Thomas Gleixner | 457c899 | 2019-05-19 13:08:55 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
| 3 | * linux/fs/locks.c |
| 4 | * |
J. Bruce Fields | e9728cc | 2021-10-19 13:38:35 -0400 | [diff] [blame] | 5 | * We implement four types of file locks: BSD locks, posix locks, open |
| 6 | * file description locks, and leases. For details about BSD locks, |
| 7 | * see the flock(2) man page; for details about the other three, see |
| 8 | * fcntl(2). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | * |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 10 | * |
| 11 | * Locking conflicts and dependencies: |
| 12 | * If multiple threads attempt to lock the same byte (or flock the same file) |
| 13 | * only one can be granted the lock, and other must wait their turn. |
| 14 | * The first lock has been "applied" or "granted", the others are "waiting" |
| 15 | * and are "blocked" by the "applied" lock.. |
| 16 | * |
| 17 | * Waiting and applied locks are all kept in trees whose properties are: |
| 18 | * |
| 19 | * - the root of a tree may be an applied or waiting lock. |
| 20 | * - every other node in the tree is a waiting lock that |
| 21 | * conflicts with every ancestor of that node. |
| 22 | * |
| 23 | * Every such tree begins life as a waiting singleton which obviously |
| 24 | * satisfies the above properties. |
| 25 | * |
| 26 | * The only ways we modify trees preserve these properties: |
| 27 | * |
| 28 | * 1. We may add a new leaf node, but only after first verifying that it |
| 29 | * conflicts with all of its ancestors. |
| 30 | * 2. We may remove the root of a tree, creating a new singleton |
| 31 | * tree from the root and N new trees rooted in the immediate |
| 32 | * children. |
| 33 | * 3. If the root of a tree is not currently an applied lock, we may |
| 34 | * apply it (if possible). |
| 35 | * 4. We may upgrade the root of the tree (either extend its range, |
| 36 | * or upgrade its entire range from read to write). |
| 37 | * |
| 38 | * When an applied lock is modified in a way that reduces or downgrades any |
| 39 | * part of its range, we remove all its children (2 above). This particularly |
| 40 | * happens when a lock is unlocked. |
| 41 | * |
| 42 | * For each of those child trees we "wake up" the thread which is |
| 43 | * waiting for the lock so it can continue handling as follows: if the |
| 44 | * root of the tree applies, we do so (3). If it doesn't, it must |
| 45 | * conflict with some applied lock. We remove (wake up) all of its children |
| 46 | * (2), and add it is a new leaf to the tree rooted in the applied |
| 47 | * lock (1). We then repeat the process recursively with those |
| 48 | * children. |
| 49 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | */ |
| 51 | |
| 52 | #include <linux/capability.h> |
| 53 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 54 | #include <linux/fdtable.h> |
Jeff Layton | 5970e15 | 2022-11-20 09:15:34 -0500 | [diff] [blame] | 55 | #include <linux/filelock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | #include <linux/fs.h> |
| 57 | #include <linux/init.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | #include <linux/security.h> |
| 59 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | #include <linux/syscalls.h> |
| 61 | #include <linux/time.h> |
Dipankar Sarma | 4fb3a53 | 2005-09-16 19:28:13 -0700 | [diff] [blame] | 62 | #include <linux/rcupdate.h> |
Vitaliy Gusev | ab1f161 | 2008-01-17 00:07:08 +0000 | [diff] [blame] | 63 | #include <linux/pid_namespace.h> |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 64 | #include <linux/hashtable.h> |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 65 | #include <linux/percpu.h> |
Luis Chamberlain | dd81faa | 2022-01-21 22:13:10 -0800 | [diff] [blame] | 66 | #include <linux/sysctl.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 68 | #define CREATE_TRACE_POINTS |
| 69 | #include <trace/events/filelock.h> |
| 70 | |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 71 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | |
| 73 | #define IS_POSIX(fl) (fl->fl_flags & FL_POSIX) |
| 74 | #define IS_FLOCK(fl) (fl->fl_flags & FL_FLOCK) |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 75 | #define IS_LEASE(fl) (fl->fl_flags & (FL_LEASE|FL_DELEG|FL_LAYOUT)) |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 76 | #define IS_OFDLCK(fl) (fl->fl_flags & FL_OFDLCK) |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame] | 77 | #define IS_REMOTELCK(fl) (fl->fl_pid <= 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
J. Bruce Fields | ab83fa4 | 2011-07-26 20:10:51 -0400 | [diff] [blame] | 79 | static bool lease_breaking(struct file_lock *fl) |
| 80 | { |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 81 | return fl->fl_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING); |
| 82 | } |
| 83 | |
| 84 | static int target_leasetype(struct file_lock *fl) |
| 85 | { |
| 86 | if (fl->fl_flags & FL_UNLOCK_PENDING) |
| 87 | return F_UNLCK; |
| 88 | if (fl->fl_flags & FL_DOWNGRADE_PENDING) |
| 89 | return F_RDLCK; |
| 90 | return fl->fl_type; |
J. Bruce Fields | ab83fa4 | 2011-07-26 20:10:51 -0400 | [diff] [blame] | 91 | } |
| 92 | |
Luis Chamberlain | dd81faa | 2022-01-21 22:13:10 -0800 | [diff] [blame] | 93 | static int leases_enable = 1; |
| 94 | static int lease_break_time = 45; |
| 95 | |
| 96 | #ifdef CONFIG_SYSCTL |
| 97 | static struct ctl_table locks_sysctls[] = { |
| 98 | { |
| 99 | .procname = "leases-enable", |
| 100 | .data = &leases_enable, |
| 101 | .maxlen = sizeof(int), |
| 102 | .mode = 0644, |
| 103 | .proc_handler = proc_dointvec, |
| 104 | }, |
| 105 | #ifdef CONFIG_MMU |
| 106 | { |
| 107 | .procname = "lease-break-time", |
| 108 | .data = &lease_break_time, |
| 109 | .maxlen = sizeof(int), |
| 110 | .mode = 0644, |
| 111 | .proc_handler = proc_dointvec, |
| 112 | }, |
| 113 | #endif /* CONFIG_MMU */ |
| 114 | {} |
| 115 | }; |
| 116 | |
| 117 | static int __init init_fs_locks_sysctls(void) |
| 118 | { |
| 119 | register_sysctl_init("fs", locks_sysctls); |
| 120 | return 0; |
| 121 | } |
| 122 | early_initcall(init_fs_locks_sysctls); |
| 123 | #endif /* CONFIG_SYSCTL */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 125 | /* |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 126 | * The global file_lock_list is only used for displaying /proc/locks, so we |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 127 | * keep a list on each CPU, with each list protected by its own spinlock. |
| 128 | * Global serialization is done using file_rwsem. |
| 129 | * |
| 130 | * Note that alterations to the list also require that the relevant flc_lock is |
| 131 | * held. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 132 | */ |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 133 | struct file_lock_list_struct { |
| 134 | spinlock_t lock; |
| 135 | struct hlist_head hlist; |
| 136 | }; |
| 137 | static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list); |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 138 | DEFINE_STATIC_PERCPU_RWSEM(file_rwsem); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 139 | |
Jeff Layton | eb82dd3 | 2019-08-18 14:18:53 -0400 | [diff] [blame] | 140 | |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 141 | /* |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 142 | * The blocked_hash is used to find POSIX lock loops for deadlock detection. |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 143 | * It is protected by blocked_lock_lock. |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 144 | * |
| 145 | * We hash locks by lockowner in order to optimize searching for the lock a |
| 146 | * particular lockowner is waiting on. |
| 147 | * |
| 148 | * FIXME: make this value scale via some heuristic? We generally will want more |
| 149 | * buckets when we have more lockowners holding locks, but that's a little |
| 150 | * difficult to determine without knowing what the workload will look like. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 151 | */ |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 152 | #define BLOCKED_HASH_BITS 7 |
| 153 | static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 154 | |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 155 | /* |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 156 | * This lock protects the blocked_hash. Generally, if you're accessing it, you |
| 157 | * want to be holding this lock. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 158 | * |
NeilBrown | ada5c1d | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 159 | * In addition, it also protects the fl->fl_blocked_requests list, and the |
| 160 | * fl->fl_blocker pointer for file_lock structures that are acting as lock |
| 161 | * requests (in contrast to those that are acting as records of acquired locks). |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 162 | * |
| 163 | * Note that when we acquire this lock in order to change the above fields, |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 164 | * we often hold the flc_lock as well. In certain cases, when reading the fields |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 165 | * protected by this lock, we can skip acquiring it iff we already hold the |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 166 | * flc_lock. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 167 | */ |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 168 | static DEFINE_SPINLOCK(blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 170 | static struct kmem_cache *flctx_cache __read_mostly; |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 171 | static struct kmem_cache *filelock_cache __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 173 | static struct file_lock_context * |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 174 | locks_get_lock_context(struct inode *inode, int type) |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 175 | { |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 176 | struct file_lock_context *ctx; |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 177 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 178 | /* paired with cmpxchg() below */ |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 179 | ctx = locks_inode_context(inode); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 180 | if (likely(ctx) || type == F_UNLCK) |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 181 | goto out; |
| 182 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 183 | ctx = kmem_cache_alloc(flctx_cache, GFP_KERNEL); |
| 184 | if (!ctx) |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 185 | goto out; |
| 186 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 187 | spin_lock_init(&ctx->flc_lock); |
| 188 | INIT_LIST_HEAD(&ctx->flc_flock); |
| 189 | INIT_LIST_HEAD(&ctx->flc_posix); |
| 190 | INIT_LIST_HEAD(&ctx->flc_lease); |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 191 | |
| 192 | /* |
| 193 | * Assign the pointer if it's not already assigned. If it is, then |
| 194 | * free the context we just allocated. |
| 195 | */ |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 196 | if (cmpxchg(&inode->i_flctx, NULL, ctx)) { |
| 197 | kmem_cache_free(flctx_cache, ctx); |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 198 | ctx = locks_inode_context(inode); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 199 | } |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 200 | out: |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 201 | trace_locks_get_lock_context(inode, type, ctx); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 202 | return ctx; |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 203 | } |
| 204 | |
Jeff Layton | e24dada | 2016-01-06 21:28:41 -0500 | [diff] [blame] | 205 | static void |
| 206 | locks_dump_ctx_list(struct list_head *list, char *list_type) |
| 207 | { |
| 208 | struct file_lock *fl; |
| 209 | |
| 210 | list_for_each_entry(fl, list, fl_list) { |
| 211 | pr_warn("%s: fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", list_type, fl->fl_owner, fl->fl_flags, fl->fl_type, fl->fl_pid); |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | static void |
| 216 | locks_check_ctx_lists(struct inode *inode) |
| 217 | { |
| 218 | struct file_lock_context *ctx = inode->i_flctx; |
| 219 | |
| 220 | if (unlikely(!list_empty(&ctx->flc_flock) || |
| 221 | !list_empty(&ctx->flc_posix) || |
| 222 | !list_empty(&ctx->flc_lease))) { |
| 223 | pr_warn("Leaked locks on dev=0x%x:0x%x ino=0x%lx:\n", |
| 224 | MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), |
| 225 | inode->i_ino); |
| 226 | locks_dump_ctx_list(&ctx->flc_flock, "FLOCK"); |
| 227 | locks_dump_ctx_list(&ctx->flc_posix, "POSIX"); |
| 228 | locks_dump_ctx_list(&ctx->flc_lease, "LEASE"); |
| 229 | } |
| 230 | } |
| 231 | |
Benjamin Coddington | 3953704 | 2017-07-21 13:36:25 -0400 | [diff] [blame] | 232 | static void |
| 233 | locks_check_ctx_file_list(struct file *filp, struct list_head *list, |
| 234 | char *list_type) |
| 235 | { |
| 236 | struct file_lock *fl; |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 237 | struct inode *inode = file_inode(filp); |
Benjamin Coddington | 3953704 | 2017-07-21 13:36:25 -0400 | [diff] [blame] | 238 | |
| 239 | list_for_each_entry(fl, list, fl_list) |
| 240 | if (fl->fl_file == filp) |
| 241 | pr_warn("Leaked %s lock on dev=0x%x:0x%x ino=0x%lx " |
| 242 | " fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", |
| 243 | list_type, MAJOR(inode->i_sb->s_dev), |
| 244 | MINOR(inode->i_sb->s_dev), inode->i_ino, |
| 245 | fl->fl_owner, fl->fl_flags, fl->fl_type, fl->fl_pid); |
| 246 | } |
| 247 | |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 248 | void |
Jeff Layton | f27a0fe | 2016-01-07 15:08:51 -0500 | [diff] [blame] | 249 | locks_free_lock_context(struct inode *inode) |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 250 | { |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 251 | struct file_lock_context *ctx = locks_inode_context(inode); |
Jeff Layton | f27a0fe | 2016-01-07 15:08:51 -0500 | [diff] [blame] | 252 | |
Jeff Layton | e24dada | 2016-01-06 21:28:41 -0500 | [diff] [blame] | 253 | if (unlikely(ctx)) { |
| 254 | locks_check_ctx_lists(inode); |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 255 | kmem_cache_free(flctx_cache, ctx); |
| 256 | } |
| 257 | } |
| 258 | |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 259 | static void locks_init_lock_heads(struct file_lock *fl) |
Miklos Szeredi | a51cb91d | 2011-07-06 12:33:55 +0200 | [diff] [blame] | 260 | { |
Jeff Layton | 139ca04 | 2013-06-21 08:58:17 -0400 | [diff] [blame] | 261 | INIT_HLIST_NODE(&fl->fl_link); |
Jeff Layton | 6dee60f | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 262 | INIT_LIST_HEAD(&fl->fl_list); |
NeilBrown | ada5c1d | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 263 | INIT_LIST_HEAD(&fl->fl_blocked_requests); |
| 264 | INIT_LIST_HEAD(&fl->fl_blocked_member); |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 265 | init_waitqueue_head(&fl->fl_wait); |
Miklos Szeredi | a51cb91d | 2011-07-06 12:33:55 +0200 | [diff] [blame] | 266 | } |
| 267 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | /* Allocate an empty lock structure. */ |
Arnd Bergmann | c5b1f0d | 2010-10-27 15:46:08 +0200 | [diff] [blame] | 269 | struct file_lock *locks_alloc_lock(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | { |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 271 | struct file_lock *fl = kmem_cache_zalloc(filelock_cache, GFP_KERNEL); |
Miklos Szeredi | a51cb91d | 2011-07-06 12:33:55 +0200 | [diff] [blame] | 272 | |
| 273 | if (fl) |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 274 | locks_init_lock_heads(fl); |
Miklos Szeredi | a51cb91d | 2011-07-06 12:33:55 +0200 | [diff] [blame] | 275 | |
| 276 | return fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | } |
Arnd Bergmann | c5b1f0d | 2010-10-27 15:46:08 +0200 | [diff] [blame] | 278 | EXPORT_SYMBOL_GPL(locks_alloc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | |
Felix Blyakher | a9e61e2 | 2009-03-31 15:12:56 -0500 | [diff] [blame] | 280 | void locks_release_private(struct file_lock *fl) |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 281 | { |
NeilBrown | 5926459 | 2019-04-24 12:00:08 +1000 | [diff] [blame] | 282 | BUG_ON(waitqueue_active(&fl->fl_wait)); |
| 283 | BUG_ON(!list_empty(&fl->fl_list)); |
| 284 | BUG_ON(!list_empty(&fl->fl_blocked_requests)); |
| 285 | BUG_ON(!list_empty(&fl->fl_blocked_member)); |
| 286 | BUG_ON(!hlist_unhashed(&fl->fl_link)); |
| 287 | |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 288 | if (fl->fl_ops) { |
| 289 | if (fl->fl_ops->fl_release_private) |
| 290 | fl->fl_ops->fl_release_private(fl); |
| 291 | fl->fl_ops = NULL; |
| 292 | } |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 293 | |
Kinglong Mee | 5c97d7b | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 294 | if (fl->fl_lmops) { |
Jeff Layton | cae80b3 | 2015-04-03 09:04:04 -0400 | [diff] [blame] | 295 | if (fl->fl_lmops->lm_put_owner) { |
| 296 | fl->fl_lmops->lm_put_owner(fl->fl_owner); |
| 297 | fl->fl_owner = NULL; |
| 298 | } |
Kinglong Mee | 5c97d7b | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 299 | fl->fl_lmops = NULL; |
| 300 | } |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 301 | } |
Felix Blyakher | a9e61e2 | 2009-03-31 15:12:56 -0500 | [diff] [blame] | 302 | EXPORT_SYMBOL_GPL(locks_release_private); |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 303 | |
Dai Ngo | 591502c5 | 2022-05-02 14:19:24 -0700 | [diff] [blame] | 304 | /** |
| 305 | * locks_owner_has_blockers - Check for blocking lock requests |
| 306 | * @flctx: file lock context |
| 307 | * @owner: lock owner |
| 308 | * |
| 309 | * Return values: |
| 310 | * %true: @owner has at least one blocker |
| 311 | * %false: @owner has no blockers |
| 312 | */ |
| 313 | bool locks_owner_has_blockers(struct file_lock_context *flctx, |
| 314 | fl_owner_t owner) |
| 315 | { |
| 316 | struct file_lock *fl; |
| 317 | |
| 318 | spin_lock(&flctx->flc_lock); |
| 319 | list_for_each_entry(fl, &flctx->flc_posix, fl_list) { |
| 320 | if (fl->fl_owner != owner) |
| 321 | continue; |
| 322 | if (!list_empty(&fl->fl_blocked_requests)) { |
| 323 | spin_unlock(&flctx->flc_lock); |
| 324 | return true; |
| 325 | } |
| 326 | } |
| 327 | spin_unlock(&flctx->flc_lock); |
| 328 | return false; |
| 329 | } |
| 330 | EXPORT_SYMBOL_GPL(locks_owner_has_blockers); |
| 331 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | /* Free a lock which is not in use. */ |
J. Bruce Fields | 05fa313 | 2010-10-30 17:31:15 -0400 | [diff] [blame] | 333 | void locks_free_lock(struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | { |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 335 | locks_release_private(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | kmem_cache_free(filelock_cache, fl); |
| 337 | } |
J. Bruce Fields | 05fa313 | 2010-10-30 17:31:15 -0400 | [diff] [blame] | 338 | EXPORT_SYMBOL(locks_free_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 340 | static void |
| 341 | locks_dispose_list(struct list_head *dispose) |
| 342 | { |
| 343 | struct file_lock *fl; |
| 344 | |
| 345 | while (!list_empty(dispose)) { |
Jeff Layton | 6dee60f | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 346 | fl = list_first_entry(dispose, struct file_lock, fl_list); |
| 347 | list_del_init(&fl->fl_list); |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 348 | locks_free_lock(fl); |
| 349 | } |
| 350 | } |
| 351 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | void locks_init_lock(struct file_lock *fl) |
| 353 | { |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 354 | memset(fl, 0, sizeof(struct file_lock)); |
| 355 | locks_init_lock_heads(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | EXPORT_SYMBOL(locks_init_lock); |
| 358 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | /* |
| 360 | * Initialize a new lock from an existing file_lock structure. |
| 361 | */ |
Kinglong Mee | 3fe0fff1 | 2014-08-22 10:18:42 -0400 | [diff] [blame] | 362 | void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | { |
| 364 | new->fl_owner = fl->fl_owner; |
| 365 | new->fl_pid = fl->fl_pid; |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 366 | new->fl_file = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | new->fl_flags = fl->fl_flags; |
| 368 | new->fl_type = fl->fl_type; |
| 369 | new->fl_start = fl->fl_start; |
| 370 | new->fl_end = fl->fl_end; |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 371 | new->fl_lmops = fl->fl_lmops; |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 372 | new->fl_ops = NULL; |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 373 | |
| 374 | if (fl->fl_lmops) { |
| 375 | if (fl->fl_lmops->lm_get_owner) |
Jeff Layton | cae80b3 | 2015-04-03 09:04:04 -0400 | [diff] [blame] | 376 | fl->fl_lmops->lm_get_owner(fl->fl_owner); |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 377 | } |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 378 | } |
Kinglong Mee | 3fe0fff1 | 2014-08-22 10:18:42 -0400 | [diff] [blame] | 379 | EXPORT_SYMBOL(locks_copy_conflock); |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 380 | |
| 381 | void locks_copy_lock(struct file_lock *new, struct file_lock *fl) |
| 382 | { |
Jeff Layton | 566709b | 2014-08-11 14:09:35 -0400 | [diff] [blame] | 383 | /* "new" must be a freshly-initialized lock */ |
| 384 | WARN_ON_ONCE(new->fl_ops); |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 385 | |
Kinglong Mee | 3fe0fff1 | 2014-08-22 10:18:42 -0400 | [diff] [blame] | 386 | locks_copy_conflock(new, fl); |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 387 | |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 388 | new->fl_file = fl->fl_file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | new->fl_ops = fl->fl_ops; |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 390 | |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 391 | if (fl->fl_ops) { |
| 392 | if (fl->fl_ops->fl_copy_lock) |
| 393 | fl->fl_ops->fl_copy_lock(new, fl); |
| 394 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | EXPORT_SYMBOL(locks_copy_lock); |
| 397 | |
NeilBrown | 5946c43 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 398 | static void locks_move_blocks(struct file_lock *new, struct file_lock *fl) |
| 399 | { |
| 400 | struct file_lock *f; |
| 401 | |
| 402 | /* |
| 403 | * As ctx->flc_lock is held, new requests cannot be added to |
| 404 | * ->fl_blocked_requests, so we don't need a lock to check if it |
| 405 | * is empty. |
| 406 | */ |
| 407 | if (list_empty(&fl->fl_blocked_requests)) |
| 408 | return; |
| 409 | spin_lock(&blocked_lock_lock); |
| 410 | list_splice_init(&fl->fl_blocked_requests, &new->fl_blocked_requests); |
NeilBrown | bf77ae4 | 2019-01-03 11:04:08 +1100 | [diff] [blame] | 411 | list_for_each_entry(f, &new->fl_blocked_requests, fl_blocked_member) |
NeilBrown | 5946c43 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 412 | f->fl_blocker = new; |
| 413 | spin_unlock(&blocked_lock_lock); |
| 414 | } |
| 415 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | static inline int flock_translate_cmd(int cmd) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | switch (cmd) { |
| 418 | case LOCK_SH: |
| 419 | return F_RDLCK; |
| 420 | case LOCK_EX: |
| 421 | return F_WRLCK; |
| 422 | case LOCK_UN: |
| 423 | return F_UNLCK; |
| 424 | } |
| 425 | return -EINVAL; |
| 426 | } |
| 427 | |
| 428 | /* Fill in a file_lock structure with an appropriate FLOCK lock. */ |
Kuniyuki Iwashima | 4149be7 | 2022-07-16 21:35:31 -0700 | [diff] [blame] | 429 | static void flock_make_lock(struct file *filp, struct file_lock *fl, int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | { |
Kuniyuki Iwashima | 4149be7 | 2022-07-16 21:35:31 -0700 | [diff] [blame] | 431 | locks_init_lock(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | |
| 433 | fl->fl_file = filp; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 434 | fl->fl_owner = filp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | fl->fl_pid = current->tgid; |
| 436 | fl->fl_flags = FL_FLOCK; |
| 437 | fl->fl_type = type; |
| 438 | fl->fl_end = OFFSET_MAX; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | } |
| 440 | |
J. Bruce Fields | 0ec4f43 | 2012-07-23 15:17:17 -0400 | [diff] [blame] | 441 | static int assign_type(struct file_lock *fl, long type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | { |
| 443 | switch (type) { |
| 444 | case F_RDLCK: |
| 445 | case F_WRLCK: |
| 446 | case F_UNLCK: |
| 447 | fl->fl_type = type; |
| 448 | break; |
| 449 | default: |
| 450 | return -EINVAL; |
| 451 | } |
| 452 | return 0; |
| 453 | } |
| 454 | |
J. Bruce Fields | ef12e72 | 2014-02-03 12:13:08 -0500 | [diff] [blame] | 455 | static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl, |
| 456 | struct flock64 *l) |
| 457 | { |
| 458 | switch (l->l_whence) { |
| 459 | case SEEK_SET: |
| 460 | fl->fl_start = 0; |
| 461 | break; |
| 462 | case SEEK_CUR: |
| 463 | fl->fl_start = filp->f_pos; |
| 464 | break; |
| 465 | case SEEK_END: |
| 466 | fl->fl_start = i_size_read(file_inode(filp)); |
| 467 | break; |
| 468 | default: |
| 469 | return -EINVAL; |
| 470 | } |
| 471 | if (l->l_start > OFFSET_MAX - fl->fl_start) |
| 472 | return -EOVERFLOW; |
| 473 | fl->fl_start += l->l_start; |
| 474 | if (fl->fl_start < 0) |
| 475 | return -EINVAL; |
| 476 | |
| 477 | /* POSIX-1996 leaves the case l->l_len < 0 undefined; |
| 478 | POSIX-2001 defines it. */ |
| 479 | if (l->l_len > 0) { |
| 480 | if (l->l_len - 1 > OFFSET_MAX - fl->fl_start) |
| 481 | return -EOVERFLOW; |
Luo Meng | 1623841 | 2020-10-23 14:20:05 +0800 | [diff] [blame] | 482 | fl->fl_end = fl->fl_start + (l->l_len - 1); |
J. Bruce Fields | ef12e72 | 2014-02-03 12:13:08 -0500 | [diff] [blame] | 483 | |
| 484 | } else if (l->l_len < 0) { |
| 485 | if (fl->fl_start + l->l_len < 0) |
| 486 | return -EINVAL; |
| 487 | fl->fl_end = fl->fl_start - 1; |
| 488 | fl->fl_start += l->l_len; |
| 489 | } else |
| 490 | fl->fl_end = OFFSET_MAX; |
| 491 | |
| 492 | fl->fl_owner = current->files; |
| 493 | fl->fl_pid = current->tgid; |
| 494 | fl->fl_file = filp; |
| 495 | fl->fl_flags = FL_POSIX; |
| 496 | fl->fl_ops = NULL; |
| 497 | fl->fl_lmops = NULL; |
| 498 | |
| 499 | return assign_type(fl, l->l_type); |
| 500 | } |
| 501 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | /* Verify a "struct flock" and copy it to a "struct file_lock" as a POSIX |
| 503 | * style lock. |
| 504 | */ |
| 505 | static int flock_to_posix_lock(struct file *filp, struct file_lock *fl, |
| 506 | struct flock *l) |
| 507 | { |
J. Bruce Fields | ef12e72 | 2014-02-03 12:13:08 -0500 | [diff] [blame] | 508 | struct flock64 ll = { |
| 509 | .l_type = l->l_type, |
| 510 | .l_whence = l->l_whence, |
| 511 | .l_start = l->l_start, |
| 512 | .l_len = l->l_len, |
| 513 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | |
J. Bruce Fields | ef12e72 | 2014-02-03 12:13:08 -0500 | [diff] [blame] | 515 | return flock64_to_posix_lock(filp, fl, &ll); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | } |
| 517 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | /* default lease lock manager operations */ |
Jeff Layton | 4d01b7f | 2014-09-01 15:06:54 -0400 | [diff] [blame] | 519 | static bool |
| 520 | lease_break_callback(struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | { |
| 522 | kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG); |
Jeff Layton | 4d01b7f | 2014-09-01 15:06:54 -0400 | [diff] [blame] | 523 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | } |
| 525 | |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 526 | static void |
| 527 | lease_setup(struct file_lock *fl, void **priv) |
| 528 | { |
| 529 | struct file *filp = fl->fl_file; |
| 530 | struct fasync_struct *fa = *priv; |
| 531 | |
| 532 | /* |
| 533 | * fasync_insert_entry() returns the old entry if any. If there was no |
| 534 | * old entry, then it used "priv" and inserted it into the fasync list. |
| 535 | * Clear the pointer to indicate that it shouldn't be freed. |
| 536 | */ |
| 537 | if (!fasync_insert_entry(fa->fa_fd, filp, &fl->fl_fasync, fa)) |
| 538 | *priv = NULL; |
| 539 | |
Eric W. Biederman | 0191913 | 2017-07-16 22:05:57 -0500 | [diff] [blame] | 540 | __f_setown(filp, task_pid(current), PIDTYPE_TGID, 0); |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 541 | } |
| 542 | |
Alexey Dobriyan | 7b02196 | 2009-09-21 17:01:12 -0700 | [diff] [blame] | 543 | static const struct lock_manager_operations lease_manager_ops = { |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 544 | .lm_break = lease_break_callback, |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 545 | .lm_change = lease_modify, |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 546 | .lm_setup = lease_setup, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | }; |
| 548 | |
| 549 | /* |
| 550 | * Initialize a lease, use the default lock manager operations |
| 551 | */ |
J. Bruce Fields | 0ec4f43 | 2012-07-23 15:17:17 -0400 | [diff] [blame] | 552 | static int lease_init(struct file *filp, long type, struct file_lock *fl) |
Joe Perches | 447a564 | 2018-03-21 15:09:32 -0700 | [diff] [blame] | 553 | { |
Trond Myklebust | 75dff55 | 2006-05-07 23:02:42 -0400 | [diff] [blame] | 554 | if (assign_type(fl, type) != 0) |
| 555 | return -EINVAL; |
| 556 | |
Jeff Layton | 7ca7631 | 2014-09-01 19:04:48 -0400 | [diff] [blame] | 557 | fl->fl_owner = filp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | fl->fl_pid = current->tgid; |
| 559 | |
| 560 | fl->fl_file = filp; |
| 561 | fl->fl_flags = FL_LEASE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | fl->fl_start = 0; |
| 563 | fl->fl_end = OFFSET_MAX; |
| 564 | fl->fl_ops = NULL; |
| 565 | fl->fl_lmops = &lease_manager_ops; |
| 566 | return 0; |
| 567 | } |
| 568 | |
| 569 | /* Allocate a file_lock initialised to this type of lease */ |
J. Bruce Fields | 0ec4f43 | 2012-07-23 15:17:17 -0400 | [diff] [blame] | 570 | static struct file_lock *lease_alloc(struct file *filp, long type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 571 | { |
| 572 | struct file_lock *fl = locks_alloc_lock(); |
Trond Myklebust | 75dff55 | 2006-05-07 23:02:42 -0400 | [diff] [blame] | 573 | int error = -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | |
| 575 | if (fl == NULL) |
J. Bruce Fields | e32b8ee | 2007-03-01 14:34:35 -0500 | [diff] [blame] | 576 | return ERR_PTR(error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | |
| 578 | error = lease_init(filp, type, fl); |
Trond Myklebust | 75dff55 | 2006-05-07 23:02:42 -0400 | [diff] [blame] | 579 | if (error) { |
| 580 | locks_free_lock(fl); |
J. Bruce Fields | e32b8ee | 2007-03-01 14:34:35 -0500 | [diff] [blame] | 581 | return ERR_PTR(error); |
Trond Myklebust | 75dff55 | 2006-05-07 23:02:42 -0400 | [diff] [blame] | 582 | } |
J. Bruce Fields | e32b8ee | 2007-03-01 14:34:35 -0500 | [diff] [blame] | 583 | return fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | } |
| 585 | |
| 586 | /* Check if two locks overlap each other. |
| 587 | */ |
| 588 | static inline int locks_overlap(struct file_lock *fl1, struct file_lock *fl2) |
| 589 | { |
| 590 | return ((fl1->fl_end >= fl2->fl_start) && |
| 591 | (fl2->fl_end >= fl1->fl_start)); |
| 592 | } |
| 593 | |
| 594 | /* |
| 595 | * Check whether two locks have the same owner. |
| 596 | */ |
Matt Mackall | 33443c4 | 2006-01-08 01:05:22 -0800 | [diff] [blame] | 597 | static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | return fl1->fl_owner == fl2->fl_owner; |
| 600 | } |
| 601 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 602 | /* Must be called with the flc_lock held! */ |
Jeff Layton | 6ca10ed | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 603 | static void locks_insert_global_locks(struct file_lock *fl) |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 604 | { |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 605 | struct file_lock_list_struct *fll = this_cpu_ptr(&file_lock_list); |
| 606 | |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 607 | percpu_rwsem_assert_held(&file_rwsem); |
| 608 | |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 609 | spin_lock(&fll->lock); |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 610 | fl->fl_link_cpu = smp_processor_id(); |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 611 | hlist_add_head(&fl->fl_link, &fll->hlist); |
| 612 | spin_unlock(&fll->lock); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 613 | } |
| 614 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 615 | /* Must be called with the flc_lock held! */ |
Jeff Layton | 6ca10ed | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 616 | static void locks_delete_global_locks(struct file_lock *fl) |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 617 | { |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 618 | struct file_lock_list_struct *fll; |
| 619 | |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 620 | percpu_rwsem_assert_held(&file_rwsem); |
| 621 | |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 622 | /* |
| 623 | * Avoid taking lock if already unhashed. This is safe since this check |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 624 | * is done while holding the flc_lock, and new insertions into the list |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 625 | * also require that it be held. |
| 626 | */ |
| 627 | if (hlist_unhashed(&fl->fl_link)) |
| 628 | return; |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 629 | |
| 630 | fll = per_cpu_ptr(&file_lock_list, fl->fl_link_cpu); |
| 631 | spin_lock(&fll->lock); |
Jeff Layton | 139ca04 | 2013-06-21 08:58:17 -0400 | [diff] [blame] | 632 | hlist_del_init(&fl->fl_link); |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 633 | spin_unlock(&fll->lock); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 634 | } |
| 635 | |
Jeff Layton | 3999e49 | 2013-06-21 08:58:19 -0400 | [diff] [blame] | 636 | static unsigned long |
| 637 | posix_owner_key(struct file_lock *fl) |
| 638 | { |
Jeff Layton | 3999e49 | 2013-06-21 08:58:19 -0400 | [diff] [blame] | 639 | return (unsigned long)fl->fl_owner; |
| 640 | } |
| 641 | |
Jeff Layton | 6ca10ed | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 642 | static void locks_insert_global_blocked(struct file_lock *waiter) |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 643 | { |
Daniel Wagner | 663d5af | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 644 | lockdep_assert_held(&blocked_lock_lock); |
| 645 | |
Jeff Layton | 3999e49 | 2013-06-21 08:58:19 -0400 | [diff] [blame] | 646 | hash_add(blocked_hash, &waiter->fl_link, posix_owner_key(waiter)); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 647 | } |
| 648 | |
Jeff Layton | 6ca10ed | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 649 | static void locks_delete_global_blocked(struct file_lock *waiter) |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 650 | { |
Daniel Wagner | 663d5af | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 651 | lockdep_assert_held(&blocked_lock_lock); |
| 652 | |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 653 | hash_del(&waiter->fl_link); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 654 | } |
| 655 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | /* Remove waiter from blocker's block list. |
| 657 | * When blocker ends up pointing to itself then the list is empty. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 658 | * |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 659 | * Must be called with blocked_lock_lock held. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | */ |
Matt Mackall | 33443c4 | 2006-01-08 01:05:22 -0800 | [diff] [blame] | 661 | static void __locks_delete_block(struct file_lock *waiter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | { |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 663 | locks_delete_global_blocked(waiter); |
NeilBrown | ada5c1d | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 664 | list_del_init(&waiter->fl_blocked_member); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | } |
| 666 | |
NeilBrown | ad6bbd8 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 667 | static void __locks_wake_up_blocks(struct file_lock *blocker) |
| 668 | { |
| 669 | while (!list_empty(&blocker->fl_blocked_requests)) { |
| 670 | struct file_lock *waiter; |
| 671 | |
| 672 | waiter = list_first_entry(&blocker->fl_blocked_requests, |
| 673 | struct file_lock, fl_blocked_member); |
| 674 | __locks_delete_block(waiter); |
| 675 | if (waiter->fl_lmops && waiter->fl_lmops->lm_notify) |
| 676 | waiter->fl_lmops->lm_notify(waiter); |
| 677 | else |
| 678 | wake_up(&waiter->fl_wait); |
Linus Torvalds | dcf23ac | 2020-03-18 07:52:21 -0400 | [diff] [blame] | 679 | |
| 680 | /* |
| 681 | * The setting of fl_blocker to NULL marks the "done" |
| 682 | * point in deleting a block. Paired with acquire at the top |
| 683 | * of locks_delete_block(). |
| 684 | */ |
| 685 | smp_store_release(&waiter->fl_blocker, NULL); |
NeilBrown | ad6bbd8 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 686 | } |
| 687 | } |
| 688 | |
NeilBrown | cb03f94 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 689 | /** |
Mauro Carvalho Chehab | 529adfe8 | 2020-10-23 18:33:23 +0200 | [diff] [blame] | 690 | * locks_delete_block - stop waiting for a file lock |
NeilBrown | cb03f94 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 691 | * @waiter: the lock which was waiting |
| 692 | * |
| 693 | * lockd/nfsd need to disconnect the lock while working on it. |
| 694 | */ |
| 695 | int locks_delete_block(struct file_lock *waiter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | { |
NeilBrown | cb03f94 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 697 | int status = -ENOENT; |
| 698 | |
Linus Torvalds | dcf23ac | 2020-03-18 07:52:21 -0400 | [diff] [blame] | 699 | /* |
| 700 | * If fl_blocker is NULL, it won't be set again as this thread "owns" |
| 701 | * the lock and is the only one that might try to claim the lock. |
| 702 | * |
| 703 | * We use acquire/release to manage fl_blocker so that we can |
| 704 | * optimize away taking the blocked_lock_lock in many cases. |
| 705 | * |
| 706 | * The smp_load_acquire guarantees two things: |
| 707 | * |
| 708 | * 1/ that fl_blocked_requests can be tested locklessly. If something |
| 709 | * was recently added to that list it must have been in a locked region |
| 710 | * *before* the locked region when fl_blocker was set to NULL. |
| 711 | * |
| 712 | * 2/ that no other thread is accessing 'waiter', so it is safe to free |
| 713 | * it. __locks_wake_up_blocks is careful not to touch waiter after |
| 714 | * fl_blocker is released. |
| 715 | * |
| 716 | * If a lockless check of fl_blocker shows it to be NULL, we know that |
| 717 | * no new locks can be inserted into its fl_blocked_requests list, and |
| 718 | * can avoid doing anything further if the list is empty. |
| 719 | */ |
| 720 | if (!smp_load_acquire(&waiter->fl_blocker) && |
| 721 | list_empty(&waiter->fl_blocked_requests)) |
| 722 | return status; |
| 723 | |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 724 | spin_lock(&blocked_lock_lock); |
NeilBrown | cb03f94 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 725 | if (waiter->fl_blocker) |
| 726 | status = 0; |
NeilBrown | 5946c43 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 727 | __locks_wake_up_blocks(waiter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | __locks_delete_block(waiter); |
Linus Torvalds | dcf23ac | 2020-03-18 07:52:21 -0400 | [diff] [blame] | 729 | |
| 730 | /* |
| 731 | * The setting of fl_blocker to NULL marks the "done" point in deleting |
| 732 | * a block. Paired with acquire at the top of this function. |
| 733 | */ |
| 734 | smp_store_release(&waiter->fl_blocker, NULL); |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 735 | spin_unlock(&blocked_lock_lock); |
NeilBrown | cb03f94 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 736 | return status; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | } |
NeilBrown | cb03f94 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 738 | EXPORT_SYMBOL(locks_delete_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | |
| 740 | /* Insert waiter into blocker's block list. |
| 741 | * We use a circular list so that processes can be easily woken up in |
| 742 | * the order they blocked. The documentation doesn't require this but |
| 743 | * it seems like the reasonable thing to do. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 744 | * |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 745 | * Must be called with both the flc_lock and blocked_lock_lock held. The |
NeilBrown | ada5c1d | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 746 | * fl_blocked_requests list itself is protected by the blocked_lock_lock, |
| 747 | * but by ensuring that the flc_lock is also held on insertions we can avoid |
| 748 | * taking the blocked_lock_lock in some cases when we see that the |
| 749 | * fl_blocked_requests list is empty. |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 750 | * |
| 751 | * Rather than just adding to the list, we check for conflicts with any existing |
| 752 | * waiters, and add beneath any waiter that blocks the new waiter. |
| 753 | * Thus wakeups don't happen until needed. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 754 | */ |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 755 | static void __locks_insert_block(struct file_lock *blocker, |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 756 | struct file_lock *waiter, |
| 757 | bool conflict(struct file_lock *, |
| 758 | struct file_lock *)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | { |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 760 | struct file_lock *fl; |
NeilBrown | ada5c1d | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 761 | BUG_ON(!list_empty(&waiter->fl_blocked_member)); |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 762 | |
| 763 | new_blocker: |
| 764 | list_for_each_entry(fl, &blocker->fl_blocked_requests, fl_blocked_member) |
| 765 | if (conflict(fl, waiter)) { |
| 766 | blocker = fl; |
| 767 | goto new_blocker; |
| 768 | } |
NeilBrown | ada5c1d | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 769 | waiter->fl_blocker = blocker; |
| 770 | list_add_tail(&waiter->fl_blocked_member, &blocker->fl_blocked_requests); |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 771 | if (IS_POSIX(blocker) && !IS_OFDLCK(blocker)) |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 772 | locks_insert_global_blocked(waiter); |
NeilBrown | 5946c43 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 773 | |
| 774 | /* The requests in waiter->fl_blocked are known to conflict with |
| 775 | * waiter, but might not conflict with blocker, or the requests |
| 776 | * and lock which block it. So they all need to be woken. |
| 777 | */ |
| 778 | __locks_wake_up_blocks(waiter); |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 779 | } |
| 780 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 781 | /* Must be called with flc_lock held. */ |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 782 | static void locks_insert_block(struct file_lock *blocker, |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 783 | struct file_lock *waiter, |
| 784 | bool conflict(struct file_lock *, |
| 785 | struct file_lock *)) |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 786 | { |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 787 | spin_lock(&blocked_lock_lock); |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 788 | __locks_insert_block(blocker, waiter, conflict); |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 789 | spin_unlock(&blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 790 | } |
| 791 | |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 792 | /* |
| 793 | * Wake up processes blocked waiting for blocker. |
| 794 | * |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 795 | * Must be called with the inode->flc_lock held! |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | */ |
| 797 | static void locks_wake_up_blocks(struct file_lock *blocker) |
| 798 | { |
Jeff Layton | 4e8c765 | 2013-06-21 08:58:16 -0400 | [diff] [blame] | 799 | /* |
| 800 | * Avoid taking global lock if list is empty. This is safe since new |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 801 | * blocked requests are only added to the list under the flc_lock, and |
NeilBrown | ada5c1d | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 802 | * the flc_lock is always held here. Note that removal from the |
| 803 | * fl_blocked_requests list does not require the flc_lock, so we must |
| 804 | * recheck list_empty() after acquiring the blocked_lock_lock. |
Jeff Layton | 4e8c765 | 2013-06-21 08:58:16 -0400 | [diff] [blame] | 805 | */ |
NeilBrown | ada5c1d | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 806 | if (list_empty(&blocker->fl_blocked_requests)) |
Jeff Layton | 4e8c765 | 2013-06-21 08:58:16 -0400 | [diff] [blame] | 807 | return; |
| 808 | |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 809 | spin_lock(&blocked_lock_lock); |
NeilBrown | ad6bbd8 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 810 | __locks_wake_up_blocks(blocker); |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 811 | spin_unlock(&blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 812 | } |
| 813 | |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 814 | static void |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 815 | locks_insert_lock_ctx(struct file_lock *fl, struct list_head *before) |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 816 | { |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 817 | list_add_tail(&fl->fl_list, before); |
| 818 | locks_insert_global_locks(fl); |
| 819 | } |
| 820 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 821 | static void |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 822 | locks_unlink_lock_ctx(struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 823 | { |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 824 | locks_delete_global_locks(fl); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 825 | list_del_init(&fl->fl_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | locks_wake_up_blocks(fl); |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 827 | } |
| 828 | |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 829 | static void |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 830 | locks_delete_lock_ctx(struct file_lock *fl, struct list_head *dispose) |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 831 | { |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 832 | locks_unlink_lock_ctx(fl); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 833 | if (dispose) |
| 834 | list_add(&fl->fl_list, dispose); |
| 835 | else |
| 836 | locks_free_lock(fl); |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 837 | } |
| 838 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 839 | /* Determine if lock sys_fl blocks lock caller_fl. Common functionality |
| 840 | * checks for shared/exclusive status of overlapping locks. |
| 841 | */ |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 842 | static bool locks_conflict(struct file_lock *caller_fl, |
| 843 | struct file_lock *sys_fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | { |
| 845 | if (sys_fl->fl_type == F_WRLCK) |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 846 | return true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 847 | if (caller_fl->fl_type == F_WRLCK) |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 848 | return true; |
| 849 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | } |
| 851 | |
| 852 | /* Determine if lock sys_fl blocks lock caller_fl. POSIX specific |
| 853 | * checking before calling the locks_conflict(). |
| 854 | */ |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 855 | static bool posix_locks_conflict(struct file_lock *caller_fl, |
| 856 | struct file_lock *sys_fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | { |
| 858 | /* POSIX locks owned by the same process do not conflict with |
| 859 | * each other. |
| 860 | */ |
Jeff Layton | 9b8c869 | 2015-04-03 09:04:02 -0400 | [diff] [blame] | 861 | if (posix_same_owner(caller_fl, sys_fl)) |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 862 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 863 | |
| 864 | /* Check whether they overlap */ |
| 865 | if (!locks_overlap(caller_fl, sys_fl)) |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 866 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 867 | |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 868 | return locks_conflict(caller_fl, sys_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 869 | } |
| 870 | |
| 871 | /* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific |
| 872 | * checking before calling the locks_conflict(). |
| 873 | */ |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 874 | static bool flock_locks_conflict(struct file_lock *caller_fl, |
| 875 | struct file_lock *sys_fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | { |
| 877 | /* FLOCK locks referring to the same filp do not conflict with |
| 878 | * each other. |
| 879 | */ |
Jeff Layton | 9b8c869 | 2015-04-03 09:04:02 -0400 | [diff] [blame] | 880 | if (caller_fl->fl_file == sys_fl->fl_file) |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 881 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | |
NeilBrown | c0e1590 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 883 | return locks_conflict(caller_fl, sys_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | } |
| 885 | |
J. Bruce Fields | 6d34ac1 | 2007-05-11 16:09:32 -0400 | [diff] [blame] | 886 | void |
Marc Eshel | 9d6a8c5 | 2007-02-21 00:55:18 -0500 | [diff] [blame] | 887 | posix_test_lock(struct file *filp, struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | { |
| 889 | struct file_lock *cfl; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 890 | struct file_lock_context *ctx; |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 891 | struct inode *inode = file_inode(filp); |
Dai Ngo | 2443da2 | 2022-05-02 14:19:25 -0700 | [diff] [blame] | 892 | void *owner; |
| 893 | void (*func)(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 894 | |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 895 | ctx = locks_inode_context(inode); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 896 | if (!ctx || list_empty_careful(&ctx->flc_posix)) { |
J. Bruce Fields | 129a84d | 2007-05-10 18:38:43 -0400 | [diff] [blame] | 897 | fl->fl_type = F_UNLCK; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 898 | return; |
| 899 | } |
| 900 | |
Dai Ngo | 2443da2 | 2022-05-02 14:19:25 -0700 | [diff] [blame] | 901 | retry: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 902 | spin_lock(&ctx->flc_lock); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 903 | list_for_each_entry(cfl, &ctx->flc_posix, fl_list) { |
Dai Ngo | 2443da2 | 2022-05-02 14:19:25 -0700 | [diff] [blame] | 904 | if (!posix_locks_conflict(fl, cfl)) |
| 905 | continue; |
| 906 | if (cfl->fl_lmops && cfl->fl_lmops->lm_lock_expirable |
| 907 | && (*cfl->fl_lmops->lm_lock_expirable)(cfl)) { |
| 908 | owner = cfl->fl_lmops->lm_mod_owner; |
| 909 | func = cfl->fl_lmops->lm_expire_lock; |
| 910 | __module_get(owner); |
| 911 | spin_unlock(&ctx->flc_lock); |
| 912 | (*func)(); |
| 913 | module_put(owner); |
| 914 | goto retry; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 915 | } |
Dai Ngo | 2443da2 | 2022-05-02 14:19:25 -0700 | [diff] [blame] | 916 | locks_copy_conflock(fl, cfl); |
| 917 | goto out; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 918 | } |
| 919 | fl->fl_type = F_UNLCK; |
| 920 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 921 | spin_unlock(&ctx->flc_lock); |
J. Bruce Fields | 6d34ac1 | 2007-05-11 16:09:32 -0400 | [diff] [blame] | 922 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | EXPORT_SYMBOL(posix_test_lock); |
| 925 | |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 926 | /* |
| 927 | * Deadlock detection: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 928 | * |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 929 | * We attempt to detect deadlocks that are due purely to posix file |
| 930 | * locks. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 931 | * |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 932 | * We assume that a task can be waiting for at most one lock at a time. |
| 933 | * So for any acquired lock, the process holding that lock may be |
| 934 | * waiting on at most one other lock. That lock in turns may be held by |
| 935 | * someone waiting for at most one other lock. Given a requested lock |
| 936 | * caller_fl which is about to wait for a conflicting lock block_fl, we |
| 937 | * follow this chain of waiters to ensure we are not about to create a |
| 938 | * cycle. |
J. Bruce Fields | 97855b4 | 2007-10-30 11:20:02 -0400 | [diff] [blame] | 939 | * |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 940 | * Since we do this before we ever put a process to sleep on a lock, we |
| 941 | * are ensured that there is never a cycle; that is what guarantees that |
| 942 | * the while() loop in posix_locks_deadlock() eventually completes. |
| 943 | * |
| 944 | * Note: the above assumption may not be true when handling lock |
| 945 | * requests from a broken NFS client. It may also fail in the presence |
| 946 | * of tasks (such as posix threads) sharing the same open file table. |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 947 | * To handle those cases, we just bail out after a few iterations. |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 948 | * |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 949 | * For FL_OFDLCK locks, the owner is the filp, not the files_struct. |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 950 | * Because the owner is not even nominally tied to a thread of |
| 951 | * execution, the deadlock detection below can't reasonably work well. Just |
| 952 | * skip it for those. |
| 953 | * |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 954 | * In principle, we could do a more limited deadlock detection on FL_OFDLCK |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 955 | * locks that just checks for the case where two tasks are attempting to |
| 956 | * upgrade from read to write locks on the same inode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | */ |
J. Bruce Fields | 97855b4 | 2007-10-30 11:20:02 -0400 | [diff] [blame] | 958 | |
| 959 | #define MAX_DEADLK_ITERATIONS 10 |
| 960 | |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 961 | /* Find a lock that the owner of the given block_fl is blocking on. */ |
| 962 | static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) |
| 963 | { |
| 964 | struct file_lock *fl; |
| 965 | |
Jeff Layton | 3999e49 | 2013-06-21 08:58:19 -0400 | [diff] [blame] | 966 | hash_for_each_possible(blocked_hash, fl, fl_link, posix_owner_key(block_fl)) { |
NeilBrown | 5946c43 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 967 | if (posix_same_owner(fl, block_fl)) { |
| 968 | while (fl->fl_blocker) |
| 969 | fl = fl->fl_blocker; |
| 970 | return fl; |
| 971 | } |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 972 | } |
| 973 | return NULL; |
| 974 | } |
| 975 | |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 976 | /* Must be called with the blocked_lock_lock held! */ |
Adrian Bunk | b0904e1 | 2006-06-23 02:05:13 -0700 | [diff] [blame] | 977 | static int posix_locks_deadlock(struct file_lock *caller_fl, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | struct file_lock *block_fl) |
| 979 | { |
J. Bruce Fields | 97855b4 | 2007-10-30 11:20:02 -0400 | [diff] [blame] | 980 | int i = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 981 | |
Daniel Wagner | 663d5af | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 982 | lockdep_assert_held(&blocked_lock_lock); |
| 983 | |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 984 | /* |
| 985 | * This deadlock detector can't reasonably detect deadlocks with |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 986 | * FL_OFDLCK locks, since they aren't owned by a process, per-se. |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 987 | */ |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 988 | if (IS_OFDLCK(caller_fl)) |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 989 | return 0; |
| 990 | |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 991 | while ((block_fl = what_owner_is_waiting_for(block_fl))) { |
| 992 | if (i++ > MAX_DEADLK_ITERATIONS) |
| 993 | return 0; |
| 994 | if (posix_same_owner(caller_fl, block_fl)) |
| 995 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 996 | } |
| 997 | return 0; |
| 998 | } |
| 999 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1000 | /* Try to create a FLOCK lock on filp. We always insert new FLOCK locks |
J. Bruce Fields | 02888f4 | 2007-09-12 15:45:07 -0400 | [diff] [blame] | 1001 | * after any leases, but before any posix locks. |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 1002 | * |
| 1003 | * Note that if called with an FL_EXISTS argument, the caller may determine |
| 1004 | * whether or not a lock was successfully freed by testing the return |
| 1005 | * value for -ENOENT. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1006 | */ |
Jeff Layton | bcd7f78d | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1007 | static int flock_lock_inode(struct inode *inode, struct file_lock *request) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | { |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 1009 | struct file_lock *new_fl = NULL; |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1010 | struct file_lock *fl; |
| 1011 | struct file_lock_context *ctx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1012 | int error = 0; |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1013 | bool found = false; |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 1014 | LIST_HEAD(dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1015 | |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 1016 | ctx = locks_get_lock_context(inode, request->fl_type); |
| 1017 | if (!ctx) { |
| 1018 | if (request->fl_type != F_UNLCK) |
| 1019 | return -ENOMEM; |
| 1020 | return (request->fl_flags & FL_EXISTS) ? -ENOENT : 0; |
| 1021 | } |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1022 | |
Arnd Bergmann | b89f432 | 2010-09-18 15:09:31 +0200 | [diff] [blame] | 1023 | if (!(request->fl_flags & FL_ACCESS) && (request->fl_type != F_UNLCK)) { |
| 1024 | new_fl = locks_alloc_lock(); |
| 1025 | if (!new_fl) |
| 1026 | return -ENOMEM; |
| 1027 | } |
| 1028 | |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1029 | percpu_down_read(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1030 | spin_lock(&ctx->flc_lock); |
Trond Myklebust | f07f18d | 2006-06-29 16:38:37 -0400 | [diff] [blame] | 1031 | if (request->fl_flags & FL_ACCESS) |
| 1032 | goto find_conflict; |
Pavel Emelyanov | 84d535a | 2007-09-11 16:38:13 +0400 | [diff] [blame] | 1033 | |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1034 | list_for_each_entry(fl, &ctx->flc_flock, fl_list) { |
Jeff Layton | bcd7f78d | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1035 | if (request->fl_file != fl->fl_file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1036 | continue; |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 1037 | if (request->fl_type == fl->fl_type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1038 | goto out; |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1039 | found = true; |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1040 | locks_delete_lock_ctx(fl, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1041 | break; |
| 1042 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1043 | |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 1044 | if (request->fl_type == F_UNLCK) { |
| 1045 | if ((request->fl_flags & FL_EXISTS) && !found) |
| 1046 | error = -ENOENT; |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 1047 | goto out; |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 1048 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1049 | |
Trond Myklebust | f07f18d | 2006-06-29 16:38:37 -0400 | [diff] [blame] | 1050 | find_conflict: |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1051 | list_for_each_entry(fl, &ctx->flc_flock, fl_list) { |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 1052 | if (!flock_locks_conflict(request, fl)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1053 | continue; |
| 1054 | error = -EAGAIN; |
Miklos Szeredi | bde74e4 | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 1055 | if (!(request->fl_flags & FL_SLEEP)) |
| 1056 | goto out; |
| 1057 | error = FILE_LOCK_DEFERRED; |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1058 | locks_insert_block(fl, request, flock_locks_conflict); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1059 | goto out; |
| 1060 | } |
Trond Myklebust | f07f18d | 2006-06-29 16:38:37 -0400 | [diff] [blame] | 1061 | if (request->fl_flags & FL_ACCESS) |
| 1062 | goto out; |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 1063 | locks_copy_lock(new_fl, request); |
NeilBrown | 5946c43 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1064 | locks_move_blocks(new_fl, request); |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1065 | locks_insert_lock_ctx(new_fl, &ctx->flc_flock); |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 1066 | new_fl = NULL; |
Kirill Korotaev | 9cedc19 | 2006-06-14 17:59:35 +0400 | [diff] [blame] | 1067 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1068 | |
| 1069 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1070 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1071 | percpu_up_read(&file_rwsem); |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 1072 | if (new_fl) |
| 1073 | locks_free_lock(new_fl); |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 1074 | locks_dispose_list(&dispose); |
Jeff Layton | c883da3 | 2018-07-30 07:54:56 -0400 | [diff] [blame] | 1075 | trace_flock_lock_inode(inode, request, error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | return error; |
| 1077 | } |
| 1078 | |
Jeff Layton | b4d629a | 2016-01-07 18:27:42 -0500 | [diff] [blame] | 1079 | static int posix_lock_inode(struct inode *inode, struct file_lock *request, |
| 1080 | struct file_lock *conflock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1081 | { |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1082 | struct file_lock *fl, *tmp; |
Miklos Szeredi | 39005d0 | 2006-06-23 02:05:10 -0700 | [diff] [blame] | 1083 | struct file_lock *new_fl = NULL; |
| 1084 | struct file_lock *new_fl2 = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | struct file_lock *left = NULL; |
| 1086 | struct file_lock *right = NULL; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1087 | struct file_lock_context *ctx; |
Jeff Layton | b9746ef | 2013-06-21 08:58:13 -0400 | [diff] [blame] | 1088 | int error; |
| 1089 | bool added = false; |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 1090 | LIST_HEAD(dispose); |
Dai Ngo | 2443da2 | 2022-05-02 14:19:25 -0700 | [diff] [blame] | 1091 | void *owner; |
| 1092 | void (*func)(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 1094 | ctx = locks_get_lock_context(inode, request->fl_type); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1095 | if (!ctx) |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 1096 | return (request->fl_type == F_UNLCK) ? 0 : -ENOMEM; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1097 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1098 | /* |
| 1099 | * We may need two file_lock structures for this operation, |
| 1100 | * so we get them in advance to avoid races. |
Miklos Szeredi | 39005d0 | 2006-06-23 02:05:10 -0700 | [diff] [blame] | 1101 | * |
| 1102 | * In some cases we can be sure, that no new locks will be needed |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1103 | */ |
Miklos Szeredi | 39005d0 | 2006-06-23 02:05:10 -0700 | [diff] [blame] | 1104 | if (!(request->fl_flags & FL_ACCESS) && |
| 1105 | (request->fl_type != F_UNLCK || |
| 1106 | request->fl_start != 0 || request->fl_end != OFFSET_MAX)) { |
| 1107 | new_fl = locks_alloc_lock(); |
| 1108 | new_fl2 = locks_alloc_lock(); |
| 1109 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1110 | |
Dai Ngo | 2443da2 | 2022-05-02 14:19:25 -0700 | [diff] [blame] | 1111 | retry: |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1112 | percpu_down_read(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1113 | spin_lock(&ctx->flc_lock); |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 1114 | /* |
| 1115 | * New lock request. Walk all POSIX locks and look for conflicts. If |
| 1116 | * there are any, either return error or put the request on the |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 1117 | * blocker's list of waiters and the global blocked_hash. |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 1118 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1119 | if (request->fl_type != F_UNLCK) { |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1120 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1121 | if (!posix_locks_conflict(request, fl)) |
| 1122 | continue; |
Dai Ngo | 2443da2 | 2022-05-02 14:19:25 -0700 | [diff] [blame] | 1123 | if (fl->fl_lmops && fl->fl_lmops->lm_lock_expirable |
| 1124 | && (*fl->fl_lmops->lm_lock_expirable)(fl)) { |
| 1125 | owner = fl->fl_lmops->lm_mod_owner; |
| 1126 | func = fl->fl_lmops->lm_expire_lock; |
| 1127 | __module_get(owner); |
| 1128 | spin_unlock(&ctx->flc_lock); |
| 1129 | percpu_up_read(&file_rwsem); |
| 1130 | (*func)(); |
| 1131 | module_put(owner); |
| 1132 | goto retry; |
| 1133 | } |
Andy Adamson | 5842add | 2006-03-26 01:37:26 -0800 | [diff] [blame] | 1134 | if (conflock) |
Kinglong Mee | 3fe0fff1 | 2014-08-22 10:18:42 -0400 | [diff] [blame] | 1135 | locks_copy_conflock(conflock, fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1136 | error = -EAGAIN; |
| 1137 | if (!(request->fl_flags & FL_SLEEP)) |
| 1138 | goto out; |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 1139 | /* |
| 1140 | * Deadlock detection and insertion into the blocked |
| 1141 | * locks list must be done while holding the same lock! |
| 1142 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1143 | error = -EDEADLK; |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 1144 | spin_lock(&blocked_lock_lock); |
Jeff Layton | 945ab8f | 2019-03-25 08:15:14 -0400 | [diff] [blame] | 1145 | /* |
| 1146 | * Ensure that we don't find any locks blocked on this |
| 1147 | * request during deadlock detection. |
| 1148 | */ |
| 1149 | __locks_wake_up_blocks(request); |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 1150 | if (likely(!posix_locks_deadlock(request, fl))) { |
| 1151 | error = FILE_LOCK_DEFERRED; |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1152 | __locks_insert_block(fl, request, |
| 1153 | posix_locks_conflict); |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 1154 | } |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 1155 | spin_unlock(&blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1156 | goto out; |
NeilBrown | 7bbd1fc | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1157 | } |
| 1158 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1159 | |
| 1160 | /* If we're just looking for a conflict, we're done. */ |
| 1161 | error = 0; |
| 1162 | if (request->fl_flags & FL_ACCESS) |
| 1163 | goto out; |
| 1164 | |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1165 | /* Find the first old lock with the same owner as the new lock */ |
| 1166 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { |
| 1167 | if (posix_same_owner(request, fl)) |
| 1168 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1169 | } |
| 1170 | |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 1171 | /* Process locks with this owner. */ |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1172 | list_for_each_entry_safe_from(fl, tmp, &ctx->flc_posix, fl_list) { |
| 1173 | if (!posix_same_owner(request, fl)) |
| 1174 | break; |
| 1175 | |
| 1176 | /* Detect adjacent or overlapping regions (if same lock type) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1177 | if (request->fl_type == fl->fl_type) { |
Olaf Kirch | 449231d | 2005-08-25 16:25:35 -0700 | [diff] [blame] | 1178 | /* In all comparisons of start vs end, use |
| 1179 | * "start - 1" rather than "end + 1". If end |
| 1180 | * is OFFSET_MAX, end + 1 will become negative. |
| 1181 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1182 | if (fl->fl_end < request->fl_start - 1) |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1183 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1184 | /* If the next lock in the list has entirely bigger |
| 1185 | * addresses than the new one, insert the lock here. |
| 1186 | */ |
Olaf Kirch | 449231d | 2005-08-25 16:25:35 -0700 | [diff] [blame] | 1187 | if (fl->fl_start - 1 > request->fl_end) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1188 | break; |
| 1189 | |
| 1190 | /* If we come here, the new and old lock are of the |
| 1191 | * same type and adjacent or overlapping. Make one |
| 1192 | * lock yielding from the lower start address of both |
| 1193 | * locks to the higher end address. |
| 1194 | */ |
| 1195 | if (fl->fl_start > request->fl_start) |
| 1196 | fl->fl_start = request->fl_start; |
| 1197 | else |
| 1198 | request->fl_start = fl->fl_start; |
| 1199 | if (fl->fl_end < request->fl_end) |
| 1200 | fl->fl_end = request->fl_end; |
| 1201 | else |
| 1202 | request->fl_end = fl->fl_end; |
| 1203 | if (added) { |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1204 | locks_delete_lock_ctx(fl, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | continue; |
| 1206 | } |
| 1207 | request = fl; |
Jeff Layton | b9746ef | 2013-06-21 08:58:13 -0400 | [diff] [blame] | 1208 | added = true; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1209 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1210 | /* Processing for different lock types is a bit |
| 1211 | * more complex. |
| 1212 | */ |
| 1213 | if (fl->fl_end < request->fl_start) |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1214 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1215 | if (fl->fl_start > request->fl_end) |
| 1216 | break; |
| 1217 | if (request->fl_type == F_UNLCK) |
Jeff Layton | b9746ef | 2013-06-21 08:58:13 -0400 | [diff] [blame] | 1218 | added = true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1219 | if (fl->fl_start < request->fl_start) |
| 1220 | left = fl; |
| 1221 | /* If the next lock in the list has a higher end |
| 1222 | * address than the new one, insert the new one here. |
| 1223 | */ |
| 1224 | if (fl->fl_end > request->fl_end) { |
| 1225 | right = fl; |
| 1226 | break; |
| 1227 | } |
| 1228 | if (fl->fl_start >= request->fl_start) { |
| 1229 | /* The new lock completely replaces an old |
| 1230 | * one (This may happen several times). |
| 1231 | */ |
| 1232 | if (added) { |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1233 | locks_delete_lock_ctx(fl, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1234 | continue; |
| 1235 | } |
Jeff Layton | b84d49f | 2014-08-12 08:03:49 -0400 | [diff] [blame] | 1236 | /* |
| 1237 | * Replace the old lock with new_fl, and |
| 1238 | * remove the old one. It's safe to do the |
| 1239 | * insert here since we know that we won't be |
| 1240 | * using new_fl later, and that the lock is |
| 1241 | * just replacing an existing lock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | */ |
Jeff Layton | b84d49f | 2014-08-12 08:03:49 -0400 | [diff] [blame] | 1243 | error = -ENOLCK; |
| 1244 | if (!new_fl) |
| 1245 | goto out; |
| 1246 | locks_copy_lock(new_fl, request); |
yangerkun | 5ef1596 | 2020-06-01 17:16:16 +0800 | [diff] [blame] | 1247 | locks_move_blocks(new_fl, request); |
Jeff Layton | b84d49f | 2014-08-12 08:03:49 -0400 | [diff] [blame] | 1248 | request = new_fl; |
| 1249 | new_fl = NULL; |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1250 | locks_insert_lock_ctx(request, &fl->fl_list); |
| 1251 | locks_delete_lock_ctx(fl, &dispose); |
Jeff Layton | b9746ef | 2013-06-21 08:58:13 -0400 | [diff] [blame] | 1252 | added = true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1253 | } |
| 1254 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1255 | } |
| 1256 | |
Miklos Szeredi | 0d9a490 | 2006-06-23 02:05:09 -0700 | [diff] [blame] | 1257 | /* |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 1258 | * The above code only modifies existing locks in case of merging or |
| 1259 | * replacing. If new lock(s) need to be inserted all modifications are |
| 1260 | * done below this, so it's safe yet to bail out. |
Miklos Szeredi | 0d9a490 | 2006-06-23 02:05:09 -0700 | [diff] [blame] | 1261 | */ |
| 1262 | error = -ENOLCK; /* "no luck" */ |
| 1263 | if (right && left == right && !new_fl2) |
| 1264 | goto out; |
| 1265 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1266 | error = 0; |
| 1267 | if (!added) { |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 1268 | if (request->fl_type == F_UNLCK) { |
| 1269 | if (request->fl_flags & FL_EXISTS) |
| 1270 | error = -ENOENT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1271 | goto out; |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 1272 | } |
Miklos Szeredi | 0d9a490 | 2006-06-23 02:05:09 -0700 | [diff] [blame] | 1273 | |
| 1274 | if (!new_fl) { |
| 1275 | error = -ENOLCK; |
| 1276 | goto out; |
| 1277 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1278 | locks_copy_lock(new_fl, request); |
NeilBrown | 5946c43 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1279 | locks_move_blocks(new_fl, request); |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1280 | locks_insert_lock_ctx(new_fl, &fl->fl_list); |
Jeff Layton | 2e2f756f | 2015-02-17 17:08:23 -0500 | [diff] [blame] | 1281 | fl = new_fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1282 | new_fl = NULL; |
| 1283 | } |
| 1284 | if (right) { |
| 1285 | if (left == right) { |
| 1286 | /* The new lock breaks the old one in two pieces, |
| 1287 | * so we have to use the second new lock. |
| 1288 | */ |
| 1289 | left = new_fl2; |
| 1290 | new_fl2 = NULL; |
| 1291 | locks_copy_lock(left, right); |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1292 | locks_insert_lock_ctx(left, &fl->fl_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1293 | } |
| 1294 | right->fl_start = request->fl_end + 1; |
| 1295 | locks_wake_up_blocks(right); |
| 1296 | } |
| 1297 | if (left) { |
| 1298 | left->fl_end = request->fl_start - 1; |
| 1299 | locks_wake_up_blocks(left); |
| 1300 | } |
| 1301 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1302 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1303 | percpu_up_read(&file_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1304 | /* |
| 1305 | * Free any unused locks. |
| 1306 | */ |
| 1307 | if (new_fl) |
| 1308 | locks_free_lock(new_fl); |
| 1309 | if (new_fl2) |
| 1310 | locks_free_lock(new_fl2); |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 1311 | locks_dispose_list(&dispose); |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 1312 | trace_posix_lock_inode(inode, request, error); |
| 1313 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1314 | return error; |
| 1315 | } |
| 1316 | |
| 1317 | /** |
| 1318 | * posix_lock_file - Apply a POSIX-style lock to a file |
| 1319 | * @filp: The file to apply the lock to |
| 1320 | * @fl: The lock to be applied |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 1321 | * @conflock: Place to return a copy of the conflicting lock, if found. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1322 | * |
| 1323 | * Add a POSIX style lock to a file. |
| 1324 | * We merge adjacent & overlapping locks whenever possible. |
| 1325 | * POSIX locks are sorted by owner task, then by starting address |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 1326 | * |
| 1327 | * Note that if called with an FL_EXISTS argument, the caller may determine |
| 1328 | * whether or not a lock was successfully freed by testing the return |
| 1329 | * value for -ENOENT. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1330 | */ |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 1331 | int posix_lock_file(struct file *filp, struct file_lock *fl, |
Andy Adamson | 5842add | 2006-03-26 01:37:26 -0800 | [diff] [blame] | 1332 | struct file_lock *conflock) |
| 1333 | { |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 1334 | return posix_lock_inode(file_inode(filp), fl, conflock); |
Andy Adamson | 5842add | 2006-03-26 01:37:26 -0800 | [diff] [blame] | 1335 | } |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 1336 | EXPORT_SYMBOL(posix_lock_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | |
| 1338 | /** |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1339 | * posix_lock_inode_wait - Apply a POSIX-style lock to a file |
| 1340 | * @inode: inode of file to which lock request should be applied |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1341 | * @fl: The lock to be applied |
| 1342 | * |
Benjamin Coddington | 616fb38 | 2015-10-22 13:38:15 -0400 | [diff] [blame] | 1343 | * Apply a POSIX style lock request to an inode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1344 | */ |
Benjamin Coddington | 616fb38 | 2015-10-22 13:38:15 -0400 | [diff] [blame] | 1345 | static int posix_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1346 | { |
| 1347 | int error; |
| 1348 | might_sleep (); |
| 1349 | for (;;) { |
Jeff Layton | b4d629a | 2016-01-07 18:27:42 -0500 | [diff] [blame] | 1350 | error = posix_lock_inode(inode, fl, NULL); |
Miklos Szeredi | bde74e4 | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 1351 | if (error != FILE_LOCK_DEFERRED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1352 | break; |
Linus Torvalds | dcf23ac | 2020-03-18 07:52:21 -0400 | [diff] [blame] | 1353 | error = wait_event_interruptible(fl->fl_wait, |
| 1354 | list_empty(&fl->fl_blocked_member)); |
NeilBrown | 16306a6 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1355 | if (error) |
| 1356 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1357 | } |
NeilBrown | 16306a6 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1358 | locks_delete_block(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1359 | return error; |
| 1360 | } |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1361 | |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1362 | static void lease_clear_pending(struct file_lock *fl, int arg) |
| 1363 | { |
| 1364 | switch (arg) { |
| 1365 | case F_UNLCK: |
| 1366 | fl->fl_flags &= ~FL_UNLOCK_PENDING; |
Gustavo A. R. Silva | df561f66 | 2020-08-23 17:36:59 -0500 | [diff] [blame] | 1367 | fallthrough; |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1368 | case F_RDLCK: |
| 1369 | fl->fl_flags &= ~FL_DOWNGRADE_PENDING; |
| 1370 | } |
| 1371 | } |
| 1372 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | /* We already had a lease on this file; just change its type */ |
Jeff Layton | 7448cc3 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1374 | int lease_modify(struct file_lock *fl, int arg, struct list_head *dispose) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1375 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1376 | int error = assign_type(fl, arg); |
| 1377 | |
| 1378 | if (error) |
| 1379 | return error; |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1380 | lease_clear_pending(fl, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | locks_wake_up_blocks(fl); |
Filipe Brandenburger | 3b6e2723 | 2012-07-27 00:42:52 -0400 | [diff] [blame] | 1382 | if (arg == F_UNLCK) { |
| 1383 | struct file *filp = fl->fl_file; |
| 1384 | |
| 1385 | f_delown(filp); |
| 1386 | filp->f_owner.signum = 0; |
J. Bruce Fields | 96d6d59 | 2012-07-27 16:18:00 -0400 | [diff] [blame] | 1387 | fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync); |
| 1388 | if (fl->fl_fasync != NULL) { |
| 1389 | printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync); |
| 1390 | fl->fl_fasync = NULL; |
| 1391 | } |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1392 | locks_delete_lock_ctx(fl, dispose); |
Filipe Brandenburger | 3b6e2723 | 2012-07-27 00:42:52 -0400 | [diff] [blame] | 1393 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1394 | return 0; |
| 1395 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | EXPORT_SYMBOL(lease_modify); |
| 1397 | |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1398 | static bool past_time(unsigned long then) |
| 1399 | { |
| 1400 | if (!then) |
| 1401 | /* 0 is a special value meaning "this never expires": */ |
| 1402 | return false; |
| 1403 | return time_after(jiffies, then); |
| 1404 | } |
| 1405 | |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1406 | static void time_out_leases(struct inode *inode, struct list_head *dispose) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1407 | { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1408 | struct file_lock_context *ctx = inode->i_flctx; |
| 1409 | struct file_lock *fl, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1410 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1411 | lockdep_assert_held(&ctx->flc_lock); |
Jeff Layton | f82b4b6 | 2014-08-22 18:50:48 -0400 | [diff] [blame] | 1412 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1413 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) { |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1414 | trace_time_out_leases(inode, fl); |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1415 | if (past_time(fl->fl_downgrade_time)) |
Jeff Layton | 7448cc3 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1416 | lease_modify(fl, F_RDLCK, dispose); |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1417 | if (past_time(fl->fl_break_time)) |
Jeff Layton | 7448cc3 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1418 | lease_modify(fl, F_UNLCK, dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1419 | } |
| 1420 | } |
| 1421 | |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1422 | static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) |
| 1423 | { |
Ira Weiny | d51f527 | 2019-06-05 18:45:34 -0700 | [diff] [blame] | 1424 | bool rc; |
| 1425 | |
J. Bruce Fields | 28df3d1 | 2017-07-28 16:35:15 -0400 | [diff] [blame] | 1426 | if (lease->fl_lmops->lm_breaker_owns_lease |
| 1427 | && lease->fl_lmops->lm_breaker_owns_lease(lease)) |
| 1428 | return false; |
Ira Weiny | d51f527 | 2019-06-05 18:45:34 -0700 | [diff] [blame] | 1429 | if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT)) { |
| 1430 | rc = false; |
| 1431 | goto trace; |
| 1432 | } |
| 1433 | if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE)) { |
| 1434 | rc = false; |
| 1435 | goto trace; |
| 1436 | } |
| 1437 | |
| 1438 | rc = locks_conflict(breaker, lease); |
| 1439 | trace: |
| 1440 | trace_leases_conflict(rc, lease, breaker); |
| 1441 | return rc; |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1442 | } |
| 1443 | |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1444 | static bool |
| 1445 | any_leases_conflict(struct inode *inode, struct file_lock *breaker) |
| 1446 | { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1447 | struct file_lock_context *ctx = inode->i_flctx; |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1448 | struct file_lock *fl; |
| 1449 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1450 | lockdep_assert_held(&ctx->flc_lock); |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1451 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1452 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1453 | if (leases_conflict(fl, breaker)) |
| 1454 | return true; |
| 1455 | } |
| 1456 | return false; |
| 1457 | } |
| 1458 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1459 | /** |
| 1460 | * __break_lease - revoke all outstanding leases on file |
| 1461 | * @inode: the inode of the file to return |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1462 | * @mode: O_RDONLY: break only write leases; O_WRONLY or O_RDWR: |
| 1463 | * break all leases |
| 1464 | * @type: FL_LEASE: break leases and delegations; FL_DELEG: break |
| 1465 | * only delegations |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1466 | * |
david m. richter | 87250dd | 2007-05-09 16:10:27 -0400 | [diff] [blame] | 1467 | * break_lease (inlined for speed) has checked there already is at least |
| 1468 | * some kind of lock (maybe a lease) on this file. Leases are broken on |
| 1469 | * a call to open() or truncate(). This function can sleep unless you |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | * specified %O_NONBLOCK to your open(). |
| 1471 | */ |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1472 | int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1473 | { |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1474 | int error = 0; |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1475 | struct file_lock_context *ctx; |
Yan, Zheng | a901125 | 2015-03-27 10:34:20 +0800 | [diff] [blame] | 1476 | struct file_lock *new_fl, *fl, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1477 | unsigned long break_time; |
Al Viro | 8737c93 | 2009-12-24 06:47:55 -0500 | [diff] [blame] | 1478 | int want_write = (mode & O_ACCMODE) != O_RDONLY; |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1479 | LIST_HEAD(dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1480 | |
Al Viro | 8737c93 | 2009-12-24 06:47:55 -0500 | [diff] [blame] | 1481 | new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); |
Linus Torvalds | 6d4b9e3 | 2011-12-26 10:25:26 -0800 | [diff] [blame] | 1482 | if (IS_ERR(new_fl)) |
| 1483 | return PTR_ERR(new_fl); |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1484 | new_fl->fl_flags = type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1485 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1486 | /* typically we will check that ctx is non-NULL before calling */ |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 1487 | ctx = locks_inode_context(inode); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1488 | if (!ctx) { |
| 1489 | WARN_ON_ONCE(1); |
Wenwen Wang | cfddf9f | 2019-08-19 18:47:34 -0500 | [diff] [blame] | 1490 | goto free_lock; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1491 | } |
| 1492 | |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1493 | percpu_down_read(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1494 | spin_lock(&ctx->flc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1495 | |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1496 | time_out_leases(inode, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1497 | |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1498 | if (!any_leases_conflict(inode, new_fl)) |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1499 | goto out; |
| 1500 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1501 | break_time = 0; |
| 1502 | if (lease_break_time > 0) { |
| 1503 | break_time = jiffies + lease_break_time * HZ; |
| 1504 | if (break_time == 0) |
| 1505 | break_time++; /* so that 0 means no break time */ |
| 1506 | } |
| 1507 | |
Yan, Zheng | a901125 | 2015-03-27 10:34:20 +0800 | [diff] [blame] | 1508 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) { |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1509 | if (!leases_conflict(fl, new_fl)) |
| 1510 | continue; |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1511 | if (want_write) { |
| 1512 | if (fl->fl_flags & FL_UNLOCK_PENDING) |
| 1513 | continue; |
| 1514 | fl->fl_flags |= FL_UNLOCK_PENDING; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1515 | fl->fl_break_time = break_time; |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1516 | } else { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1517 | if (lease_breaking(fl)) |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1518 | continue; |
| 1519 | fl->fl_flags |= FL_DOWNGRADE_PENDING; |
| 1520 | fl->fl_downgrade_time = break_time; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1521 | } |
Jeff Layton | 4d01b7f | 2014-09-01 15:06:54 -0400 | [diff] [blame] | 1522 | if (fl->fl_lmops->lm_break(fl)) |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1523 | locks_delete_lock_ctx(fl, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1524 | } |
| 1525 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1526 | if (list_empty(&ctx->flc_lease)) |
Jeff Layton | 4d01b7f | 2014-09-01 15:06:54 -0400 | [diff] [blame] | 1527 | goto out; |
| 1528 | |
Jeff Layton | 843c6b2 | 2014-09-01 14:27:43 -0400 | [diff] [blame] | 1529 | if (mode & O_NONBLOCK) { |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1530 | trace_break_lease_noblock(inode, new_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1531 | error = -EWOULDBLOCK; |
| 1532 | goto out; |
| 1533 | } |
| 1534 | |
| 1535 | restart: |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1536 | fl = list_first_entry(&ctx->flc_lease, struct file_lock, fl_list); |
| 1537 | break_time = fl->fl_break_time; |
Jeff Layton | f1c6bb2 | 2014-04-15 06:17:49 -0400 | [diff] [blame] | 1538 | if (break_time != 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1539 | break_time -= jiffies; |
Jeff Layton | f1c6bb2 | 2014-04-15 06:17:49 -0400 | [diff] [blame] | 1540 | if (break_time == 0) |
| 1541 | break_time++; |
NeilBrown | fd7732e | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1542 | locks_insert_block(fl, new_fl, leases_conflict); |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1543 | trace_break_lease_block(inode, new_fl); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1544 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1545 | percpu_up_read(&file_rwsem); |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 1546 | |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1547 | locks_dispose_list(&dispose); |
Matthew Wilcox | 4321e01 | 2008-01-14 21:28:30 -0700 | [diff] [blame] | 1548 | error = wait_event_interruptible_timeout(new_fl->fl_wait, |
Linus Torvalds | dcf23ac | 2020-03-18 07:52:21 -0400 | [diff] [blame] | 1549 | list_empty(&new_fl->fl_blocked_member), |
| 1550 | break_time); |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 1551 | |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1552 | percpu_down_read(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1553 | spin_lock(&ctx->flc_lock); |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1554 | trace_break_lease_unblock(inode, new_fl); |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 1555 | locks_delete_block(new_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1556 | if (error >= 0) { |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1557 | /* |
| 1558 | * Wait for the next conflicting lease that has not been |
| 1559 | * broken yet |
| 1560 | */ |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1561 | if (error == 0) |
| 1562 | time_out_leases(inode, &dispose); |
| 1563 | if (any_leases_conflict(inode, new_fl)) |
| 1564 | goto restart; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1565 | error = 0; |
| 1566 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1567 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1568 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1569 | percpu_up_read(&file_rwsem); |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1570 | locks_dispose_list(&dispose); |
Wenwen Wang | cfddf9f | 2019-08-19 18:47:34 -0500 | [diff] [blame] | 1571 | free_lock: |
Linus Torvalds | 6d4b9e3 | 2011-12-26 10:25:26 -0800 | [diff] [blame] | 1572 | locks_free_lock(new_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1573 | return error; |
| 1574 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1575 | EXPORT_SYMBOL(__break_lease); |
| 1576 | |
| 1577 | /** |
Amir Goldstein | 76c4794 | 2018-01-03 17:14:34 +0200 | [diff] [blame] | 1578 | * lease_get_mtime - update modified time of an inode with exclusive lease |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1579 | * @inode: the inode |
Amir Goldstein | 76c4794 | 2018-01-03 17:14:34 +0200 | [diff] [blame] | 1580 | * @time: pointer to a timespec which contains the last modified time |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1581 | * |
| 1582 | * This is to force NFS clients to flush their caches for files with |
| 1583 | * exclusive leases. The justification is that if someone has an |
Randy Dunlap | a6b9191 | 2008-03-19 17:01:00 -0700 | [diff] [blame] | 1584 | * exclusive lease, then they could be modifying it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1585 | */ |
Deepa Dinamani | 95582b0 | 2018-05-08 19:36:02 -0700 | [diff] [blame] | 1586 | void lease_get_mtime(struct inode *inode, struct timespec64 *time) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1587 | { |
Jeff Layton | bfe8602 | 2014-08-22 10:18:44 -0400 | [diff] [blame] | 1588 | bool has_lease = false; |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1589 | struct file_lock_context *ctx; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1590 | struct file_lock *fl; |
Jeff Layton | bfe8602 | 2014-08-22 10:18:44 -0400 | [diff] [blame] | 1591 | |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 1592 | ctx = locks_inode_context(inode); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1593 | if (ctx && !list_empty_careful(&ctx->flc_lease)) { |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1594 | spin_lock(&ctx->flc_lock); |
Geliang Tang | 8ace5df | 2015-11-18 21:40:33 +0800 | [diff] [blame] | 1595 | fl = list_first_entry_or_null(&ctx->flc_lease, |
| 1596 | struct file_lock, fl_list); |
| 1597 | if (fl && (fl->fl_type == F_WRLCK)) |
| 1598 | has_lease = true; |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1599 | spin_unlock(&ctx->flc_lock); |
Jeff Layton | bfe8602 | 2014-08-22 10:18:44 -0400 | [diff] [blame] | 1600 | } |
| 1601 | |
| 1602 | if (has_lease) |
Deepa Dinamani | c2050a4 | 2016-09-14 07:48:06 -0700 | [diff] [blame] | 1603 | *time = current_time(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1604 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1605 | EXPORT_SYMBOL(lease_get_mtime); |
| 1606 | |
| 1607 | /** |
| 1608 | * fcntl_getlease - Enquire what lease is currently active |
| 1609 | * @filp: the file |
| 1610 | * |
| 1611 | * The value returned by this function will be one of |
| 1612 | * (if no lease break is pending): |
| 1613 | * |
| 1614 | * %F_RDLCK to indicate a shared lease is held. |
| 1615 | * |
| 1616 | * %F_WRLCK to indicate an exclusive lease is held. |
| 1617 | * |
| 1618 | * %F_UNLCK to indicate no lease is held. |
| 1619 | * |
| 1620 | * (if a lease break is pending): |
| 1621 | * |
| 1622 | * %F_RDLCK to indicate an exclusive lease needs to be |
| 1623 | * changed to a shared lease (or removed). |
| 1624 | * |
| 1625 | * %F_UNLCK to indicate the lease needs to be removed. |
| 1626 | * |
| 1627 | * XXX: sfr & willy disagree over whether F_INPROGRESS |
| 1628 | * should be returned to userspace. |
| 1629 | */ |
| 1630 | int fcntl_getlease(struct file *filp) |
| 1631 | { |
| 1632 | struct file_lock *fl; |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 1633 | struct inode *inode = file_inode(filp); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1634 | struct file_lock_context *ctx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1635 | int type = F_UNLCK; |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1636 | LIST_HEAD(dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1637 | |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 1638 | ctx = locks_inode_context(inode); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1639 | if (ctx && !list_empty_careful(&ctx->flc_lease)) { |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1640 | percpu_down_read(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1641 | spin_lock(&ctx->flc_lock); |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 1642 | time_out_leases(inode, &dispose); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1643 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
| 1644 | if (fl->fl_file != filp) |
| 1645 | continue; |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1646 | type = target_leasetype(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1647 | break; |
| 1648 | } |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1649 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1650 | percpu_up_read(&file_rwsem); |
Peter Zijlstra | 5f43086 | 2016-10-08 10:12:28 +0200 | [diff] [blame] | 1651 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1652 | locks_dispose_list(&dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1653 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1654 | return type; |
| 1655 | } |
| 1656 | |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1657 | /** |
Amir Goldstein | 387e374 | 2019-06-07 17:24:38 +0300 | [diff] [blame] | 1658 | * check_conflicting_open - see if the given file points to an inode that has |
NeilBrown | 7bbd1fc | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1659 | * an existing open that would conflict with the |
| 1660 | * desired lease. |
Amir Goldstein | 387e374 | 2019-06-07 17:24:38 +0300 | [diff] [blame] | 1661 | * @filp: file to check |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1662 | * @arg: type of lease that we're trying to acquire |
Randy Dunlap | 7fadc59 | 2015-08-09 18:43:17 -0700 | [diff] [blame] | 1663 | * @flags: current lock flags |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1664 | * |
| 1665 | * Check to see if there's an existing open fd on this file that would |
| 1666 | * conflict with the lease we're trying to set. |
| 1667 | */ |
| 1668 | static int |
Amir Goldstein | 387e374 | 2019-06-07 17:24:38 +0300 | [diff] [blame] | 1669 | check_conflicting_open(struct file *filp, const long arg, int flags) |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1670 | { |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 1671 | struct inode *inode = file_inode(filp); |
Amir Goldstein | 387e374 | 2019-06-07 17:24:38 +0300 | [diff] [blame] | 1672 | int self_wcount = 0, self_rcount = 0; |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1673 | |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 1674 | if (flags & FL_LAYOUT) |
| 1675 | return 0; |
J. Bruce Fields | aba2072 | 2021-04-16 14:00:18 -0400 | [diff] [blame] | 1676 | if (flags & FL_DELEG) |
| 1677 | /* We leave these checks to the caller */ |
| 1678 | return 0; |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 1679 | |
Amir Goldstein | 387e374 | 2019-06-07 17:24:38 +0300 | [diff] [blame] | 1680 | if (arg == F_RDLCK) |
| 1681 | return inode_is_open_for_write(inode) ? -EAGAIN : 0; |
| 1682 | else if (arg != F_WRLCK) |
| 1683 | return 0; |
| 1684 | |
| 1685 | /* |
| 1686 | * Make sure that only read/write count is from lease requestor. |
| 1687 | * Note that this will result in denying write leases when i_writecount |
| 1688 | * is negative, which is what we want. (We shouldn't grant write leases |
| 1689 | * on files open for execution.) |
| 1690 | */ |
| 1691 | if (filp->f_mode & FMODE_WRITE) |
| 1692 | self_wcount = 1; |
| 1693 | else if (filp->f_mode & FMODE_READ) |
| 1694 | self_rcount = 1; |
| 1695 | |
| 1696 | if (atomic_read(&inode->i_writecount) != self_wcount || |
| 1697 | atomic_read(&inode->i_readcount) != self_rcount) |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1698 | return -EAGAIN; |
| 1699 | |
Amir Goldstein | 387e374 | 2019-06-07 17:24:38 +0300 | [diff] [blame] | 1700 | return 0; |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1701 | } |
| 1702 | |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1703 | static int |
| 1704 | generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1705 | { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1706 | struct file_lock *fl, *my_fl = NULL, *lease; |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 1707 | struct inode *inode = file_inode(filp); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1708 | struct file_lock_context *ctx; |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1709 | bool is_deleg = (*flp)->fl_flags & FL_DELEG; |
J. Bruce Fields | c1f24ef | 2011-08-19 10:59:49 -0400 | [diff] [blame] | 1710 | int error; |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1711 | LIST_HEAD(dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1712 | |
J. Bruce Fields | 096657b | 2010-10-30 17:31:14 -0400 | [diff] [blame] | 1713 | lease = *flp; |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1714 | trace_generic_add_lease(inode, lease); |
| 1715 | |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 1716 | /* Note that arg is never F_UNLCK here */ |
| 1717 | ctx = locks_get_lock_context(inode, arg); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1718 | if (!ctx) |
| 1719 | return -ENOMEM; |
| 1720 | |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1721 | /* |
| 1722 | * In the delegation case we need mutual exclusion with |
| 1723 | * a number of operations that take the i_mutex. We trylock |
| 1724 | * because delegations are an optional optimization, and if |
| 1725 | * there's some chance of a conflict--we'd rather not |
| 1726 | * bother, maybe that's a sign this just isn't a good file to |
| 1727 | * hand out a delegation on. |
| 1728 | */ |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1729 | if (is_deleg && !inode_trylock(inode)) |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1730 | return -EAGAIN; |
| 1731 | |
| 1732 | if (is_deleg && arg == F_WRLCK) { |
| 1733 | /* Write delegations are not currently supported: */ |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1734 | inode_unlock(inode); |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1735 | WARN_ON_ONCE(1); |
| 1736 | return -EINVAL; |
| 1737 | } |
J. Bruce Fields | 096657b | 2010-10-30 17:31:14 -0400 | [diff] [blame] | 1738 | |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1739 | percpu_down_read(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1740 | spin_lock(&ctx->flc_lock); |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1741 | time_out_leases(inode, &dispose); |
Amir Goldstein | 387e374 | 2019-06-07 17:24:38 +0300 | [diff] [blame] | 1742 | error = check_conflicting_open(filp, arg, lease->fl_flags); |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1743 | if (error) |
J. Bruce Fields | 096657b | 2010-10-30 17:31:14 -0400 | [diff] [blame] | 1744 | goto out; |
Pavel Emelyanov | 85c5958 | 2007-09-20 12:45:02 +0400 | [diff] [blame] | 1745 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1746 | /* |
| 1747 | * At this point, we know that if there is an exclusive |
| 1748 | * lease on this file, then we hold it on this filp |
| 1749 | * (otherwise our open of this file would have blocked). |
| 1750 | * And if we are trying to acquire an exclusive lease, |
| 1751 | * then the file is not open by anyone (including us) |
| 1752 | * except for this filp. |
| 1753 | */ |
J. Bruce Fields | c1f24ef | 2011-08-19 10:59:49 -0400 | [diff] [blame] | 1754 | error = -EAGAIN; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1755 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1756 | if (fl->fl_file == filp && |
| 1757 | fl->fl_owner == lease->fl_owner) { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1758 | my_fl = fl; |
J. Bruce Fields | c1f24ef | 2011-08-19 10:59:49 -0400 | [diff] [blame] | 1759 | continue; |
| 1760 | } |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1761 | |
J. Bruce Fields | c1f24ef | 2011-08-19 10:59:49 -0400 | [diff] [blame] | 1762 | /* |
| 1763 | * No exclusive leases if someone else has a lease on |
| 1764 | * this file: |
| 1765 | */ |
| 1766 | if (arg == F_WRLCK) |
| 1767 | goto out; |
| 1768 | /* |
| 1769 | * Modifying our existing lease is OK, but no getting a |
| 1770 | * new lease if someone else is opening for write: |
| 1771 | */ |
| 1772 | if (fl->fl_flags & FL_UNLOCK_PENDING) |
| 1773 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1774 | } |
| 1775 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1776 | if (my_fl != NULL) { |
Jeff Layton | 0164bf0 | 2015-03-04 17:34:32 -0500 | [diff] [blame] | 1777 | lease = my_fl; |
| 1778 | error = lease->fl_lmops->lm_change(lease, arg, &dispose); |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1779 | if (error) |
| 1780 | goto out; |
| 1781 | goto out_setup; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1782 | } |
| 1783 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1784 | error = -EINVAL; |
| 1785 | if (!leases_enable) |
| 1786 | goto out; |
| 1787 | |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1788 | locks_insert_lock_ctx(lease, &ctx->flc_lease); |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1789 | /* |
| 1790 | * The check in break_lease() is lockless. It's possible for another |
| 1791 | * open to race in after we did the earlier check for a conflicting |
| 1792 | * open but before the lease was inserted. Check again for a |
| 1793 | * conflicting open and cancel the lease if there is one. |
| 1794 | * |
| 1795 | * We also add a barrier here to ensure that the insertion of the lock |
| 1796 | * precedes these checks. |
| 1797 | */ |
| 1798 | smp_mb(); |
Amir Goldstein | 387e374 | 2019-06-07 17:24:38 +0300 | [diff] [blame] | 1799 | error = check_conflicting_open(filp, arg, lease->fl_flags); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1800 | if (error) { |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1801 | locks_unlink_lock_ctx(lease); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1802 | goto out; |
| 1803 | } |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1804 | |
| 1805 | out_setup: |
| 1806 | if (lease->fl_lmops->lm_setup) |
| 1807 | lease->fl_lmops->lm_setup(lease, priv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1808 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1809 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1810 | percpu_up_read(&file_rwsem); |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1811 | locks_dispose_list(&dispose); |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1812 | if (is_deleg) |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1813 | inode_unlock(inode); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1814 | if (!error && !my_fl) |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1815 | *flp = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1816 | return error; |
| 1817 | } |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1818 | |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1819 | static int generic_delete_lease(struct file *filp, void *owner) |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1820 | { |
Jeff Layton | 0efaa7e | 2014-08-22 10:18:45 -0400 | [diff] [blame] | 1821 | int error = -EAGAIN; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1822 | struct file_lock *fl, *victim = NULL; |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 1823 | struct inode *inode = file_inode(filp); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1824 | struct file_lock_context *ctx; |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1825 | LIST_HEAD(dispose); |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1826 | |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 1827 | ctx = locks_inode_context(inode); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1828 | if (!ctx) { |
| 1829 | trace_generic_delete_lease(inode, NULL); |
| 1830 | return error; |
| 1831 | } |
| 1832 | |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1833 | percpu_down_read(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1834 | spin_lock(&ctx->flc_lock); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1835 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1836 | if (fl->fl_file == filp && |
| 1837 | fl->fl_owner == owner) { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1838 | victim = fl; |
Jeff Layton | 0efaa7e | 2014-08-22 10:18:45 -0400 | [diff] [blame] | 1839 | break; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1840 | } |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1841 | } |
Jeff Layton | a9b1b45 | 2015-03-14 09:45:35 -0400 | [diff] [blame] | 1842 | trace_generic_delete_lease(inode, victim); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1843 | if (victim) |
Jeff Layton | 7448cc3 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1844 | error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1845 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 1846 | percpu_up_read(&file_rwsem); |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1847 | locks_dispose_list(&dispose); |
Jeff Layton | 0efaa7e | 2014-08-22 10:18:45 -0400 | [diff] [blame] | 1848 | return error; |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1849 | } |
| 1850 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1851 | /** |
| 1852 | * generic_setlease - sets a lease on an open file |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1853 | * @filp: file pointer |
| 1854 | * @arg: type of lease to obtain |
| 1855 | * @flp: input - file_lock to use, output - file_lock inserted |
| 1856 | * @priv: private data for lm_setup (may be NULL if lm_setup |
| 1857 | * doesn't require it) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1858 | * |
| 1859 | * The (input) flp->fl_lmops->lm_break function is required |
| 1860 | * by break_lease(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1861 | */ |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1862 | int generic_setlease(struct file *filp, long arg, struct file_lock **flp, |
| 1863 | void **priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1864 | { |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 1865 | struct inode *inode = file_inode(filp); |
Seth Forshee | 42d0c4b | 2023-03-09 14:39:09 -0600 | [diff] [blame] | 1866 | vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_idmap(filp), inode); |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1867 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1868 | |
Seth Forshee | 42d0c4b | 2023-03-09 14:39:09 -0600 | [diff] [blame] | 1869 | if ((!vfsuid_eq_kuid(vfsuid, current_fsuid())) && !capable(CAP_LEASE)) |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1870 | return -EACCES; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1871 | if (!S_ISREG(inode->i_mode)) |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1872 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1873 | error = security_file_lock(filp, arg); |
| 1874 | if (error) |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1875 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1876 | |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1877 | switch (arg) { |
| 1878 | case F_UNLCK: |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1879 | return generic_delete_lease(filp, *priv); |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1880 | case F_RDLCK: |
| 1881 | case F_WRLCK: |
Jeff Layton | 0efaa7e | 2014-08-22 10:18:45 -0400 | [diff] [blame] | 1882 | if (!(*flp)->fl_lmops->lm_break) { |
| 1883 | WARN_ON_ONCE(1); |
| 1884 | return -ENOLCK; |
| 1885 | } |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 1886 | |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1887 | return generic_add_lease(filp, arg, flp, priv); |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1888 | default: |
Dave Jones | 8d657eb | 2012-07-13 13:35:36 -0400 | [diff] [blame] | 1889 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1890 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1891 | } |
Christoph Hellwig | 0af1a45 | 2007-07-31 00:39:22 -0700 | [diff] [blame] | 1892 | EXPORT_SYMBOL(generic_setlease); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1893 | |
Jeff Layton | 18f6622 | 2019-08-18 14:18:45 -0400 | [diff] [blame] | 1894 | /* |
| 1895 | * Kernel subsystems can register to be notified on any attempt to set |
| 1896 | * a new lease with the lease_notifier_chain. This is used by (e.g.) nfsd |
| 1897 | * to close files that it may have cached when there is an attempt to set a |
| 1898 | * conflicting lease. |
| 1899 | */ |
| 1900 | static struct srcu_notifier_head lease_notifier_chain; |
| 1901 | |
| 1902 | static inline void |
| 1903 | lease_notifier_chain_init(void) |
| 1904 | { |
| 1905 | srcu_init_notifier_head(&lease_notifier_chain); |
| 1906 | } |
| 1907 | |
| 1908 | static inline void |
| 1909 | setlease_notifier(long arg, struct file_lock *lease) |
| 1910 | { |
| 1911 | if (arg != F_UNLCK) |
| 1912 | srcu_notifier_call_chain(&lease_notifier_chain, arg, lease); |
| 1913 | } |
| 1914 | |
| 1915 | int lease_register_notifier(struct notifier_block *nb) |
| 1916 | { |
| 1917 | return srcu_notifier_chain_register(&lease_notifier_chain, nb); |
| 1918 | } |
| 1919 | EXPORT_SYMBOL_GPL(lease_register_notifier); |
| 1920 | |
| 1921 | void lease_unregister_notifier(struct notifier_block *nb) |
| 1922 | { |
| 1923 | srcu_notifier_chain_unregister(&lease_notifier_chain, nb); |
| 1924 | } |
| 1925 | EXPORT_SYMBOL_GPL(lease_unregister_notifier); |
| 1926 | |
Arnd Bergmann | b89f432 | 2010-09-18 15:09:31 +0200 | [diff] [blame] | 1927 | /** |
Jeff Layton | e51673a | 2014-08-22 18:13:28 -0400 | [diff] [blame] | 1928 | * vfs_setlease - sets a lease on an open file |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1929 | * @filp: file pointer |
| 1930 | * @arg: type of lease to obtain |
| 1931 | * @lease: file_lock to use when adding a lease |
| 1932 | * @priv: private info for lm_setup when adding a lease (may be |
NeilBrown | 7bbd1fc | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 1933 | * NULL if lm_setup doesn't require it) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1934 | * |
Jeff Layton | e51673a | 2014-08-22 18:13:28 -0400 | [diff] [blame] | 1935 | * Call this to establish a lease on the file. The "lease" argument is not |
| 1936 | * used for F_UNLCK requests and may be NULL. For commands that set or alter |
Mauro Carvalho Chehab | 80b79dd | 2017-05-27 06:07:18 -0400 | [diff] [blame] | 1937 | * an existing lease, the ``(*lease)->fl_lmops->lm_break`` operation must be |
| 1938 | * set; if not, this function will return -ENOLCK (and generate a scary-looking |
Jeff Layton | e51673a | 2014-08-22 18:13:28 -0400 | [diff] [blame] | 1939 | * stack trace). |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1940 | * |
| 1941 | * The "priv" pointer is passed directly to the lm_setup function as-is. It |
| 1942 | * may be NULL if the lm_setup operation doesn't require it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1943 | */ |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1944 | int |
| 1945 | vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1946 | { |
Jeff Layton | 18f6622 | 2019-08-18 14:18:45 -0400 | [diff] [blame] | 1947 | if (lease) |
| 1948 | setlease_notifier(arg, *lease); |
Miklos Szeredi | de2a4a5 | 2018-07-18 15:44:43 +0200 | [diff] [blame] | 1949 | if (filp->f_op->setlease) |
Jeff Layton | f82b4b6 | 2014-08-22 18:50:48 -0400 | [diff] [blame] | 1950 | return filp->f_op->setlease(filp, arg, lease, priv); |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1951 | else |
Jeff Layton | f82b4b6 | 2014-08-22 18:50:48 -0400 | [diff] [blame] | 1952 | return generic_setlease(filp, arg, lease, priv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1953 | } |
J. Bruce Fields | a9933ce | 2007-06-07 17:09:49 -0400 | [diff] [blame] | 1954 | EXPORT_SYMBOL_GPL(vfs_setlease); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1955 | |
J. Bruce Fields | 0ceaf6c | 2010-10-30 17:31:13 -0400 | [diff] [blame] | 1956 | static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1957 | { |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1958 | struct file_lock *fl; |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 1959 | struct fasync_struct *new; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1960 | int error; |
| 1961 | |
Arnd Bergmann | c5b1f0d | 2010-10-27 15:46:08 +0200 | [diff] [blame] | 1962 | fl = lease_alloc(filp, arg); |
| 1963 | if (IS_ERR(fl)) |
| 1964 | return PTR_ERR(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1965 | |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 1966 | new = fasync_alloc(); |
| 1967 | if (!new) { |
| 1968 | locks_free_lock(fl); |
| 1969 | return -ENOMEM; |
| 1970 | } |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1971 | new->fa_fd = fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1972 | |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1973 | error = vfs_setlease(filp, arg, &fl, (void **)&new); |
Jeff Layton | 2dfb928 | 2014-08-11 18:14:12 -0400 | [diff] [blame] | 1974 | if (fl) |
| 1975 | locks_free_lock(fl); |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 1976 | if (new) |
| 1977 | fasync_free(new); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1978 | return error; |
| 1979 | } |
| 1980 | |
| 1981 | /** |
J. Bruce Fields | 0ceaf6c | 2010-10-30 17:31:13 -0400 | [diff] [blame] | 1982 | * fcntl_setlease - sets a lease on an open file |
| 1983 | * @fd: open file descriptor |
| 1984 | * @filp: file pointer |
| 1985 | * @arg: type of lease to obtain |
| 1986 | * |
| 1987 | * Call this fcntl to establish a lease on the file. |
| 1988 | * Note that you also need to call %F_SETSIG to |
| 1989 | * receive a signal when the lease is broken. |
| 1990 | */ |
| 1991 | int fcntl_setlease(unsigned int fd, struct file *filp, long arg) |
| 1992 | { |
| 1993 | if (arg == F_UNLCK) |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1994 | return vfs_setlease(filp, F_UNLCK, NULL, (void **)&filp); |
J. Bruce Fields | 0ceaf6c | 2010-10-30 17:31:13 -0400 | [diff] [blame] | 1995 | return do_fcntl_add_lease(fd, filp, arg); |
| 1996 | } |
| 1997 | |
| 1998 | /** |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1999 | * flock_lock_inode_wait - Apply a FLOCK-style lock to a file |
| 2000 | * @inode: inode of the file to apply to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2001 | * @fl: The lock to be applied |
| 2002 | * |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 2003 | * Apply a FLOCK style lock request to an inode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2004 | */ |
Benjamin Coddington | 616fb38 | 2015-10-22 13:38:15 -0400 | [diff] [blame] | 2005 | static int flock_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2006 | { |
| 2007 | int error; |
| 2008 | might_sleep(); |
| 2009 | for (;;) { |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 2010 | error = flock_lock_inode(inode, fl); |
Miklos Szeredi | bde74e4 | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2011 | if (error != FILE_LOCK_DEFERRED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2012 | break; |
Linus Torvalds | dcf23ac | 2020-03-18 07:52:21 -0400 | [diff] [blame] | 2013 | error = wait_event_interruptible(fl->fl_wait, |
| 2014 | list_empty(&fl->fl_blocked_member)); |
NeilBrown | 16306a6 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 2015 | if (error) |
| 2016 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2017 | } |
NeilBrown | 16306a6 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 2018 | locks_delete_block(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2019 | return error; |
| 2020 | } |
| 2021 | |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 2022 | /** |
Benjamin Coddington | e55c34a | 2015-10-22 13:38:13 -0400 | [diff] [blame] | 2023 | * locks_lock_inode_wait - Apply a lock to an inode |
| 2024 | * @inode: inode of the file to apply to |
| 2025 | * @fl: The lock to be applied |
| 2026 | * |
| 2027 | * Apply a POSIX or FLOCK style lock request to an inode. |
| 2028 | */ |
| 2029 | int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
| 2030 | { |
| 2031 | int res = 0; |
| 2032 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { |
| 2033 | case FL_POSIX: |
| 2034 | res = posix_lock_inode_wait(inode, fl); |
| 2035 | break; |
| 2036 | case FL_FLOCK: |
| 2037 | res = flock_lock_inode_wait(inode, fl); |
| 2038 | break; |
| 2039 | default: |
| 2040 | BUG(); |
| 2041 | } |
| 2042 | return res; |
| 2043 | } |
| 2044 | EXPORT_SYMBOL(locks_lock_inode_wait); |
| 2045 | |
| 2046 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2047 | * sys_flock: - flock() system call. |
| 2048 | * @fd: the file descriptor to lock. |
| 2049 | * @cmd: the type of lock to apply. |
| 2050 | * |
| 2051 | * Apply a %FL_FLOCK style lock to an open file descriptor. |
Mauro Carvalho Chehab | 80b79dd | 2017-05-27 06:07:18 -0400 | [diff] [blame] | 2052 | * The @cmd can be one of: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2053 | * |
Mauro Carvalho Chehab | 80b79dd | 2017-05-27 06:07:18 -0400 | [diff] [blame] | 2054 | * - %LOCK_SH -- a shared lock. |
| 2055 | * - %LOCK_EX -- an exclusive lock. |
| 2056 | * - %LOCK_UN -- remove an existing lock. |
Jeff Layton | 90f7d7a | 2021-09-10 15:36:29 -0400 | [diff] [blame] | 2057 | * - %LOCK_MAND -- a 'mandatory' flock. (DEPRECATED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2058 | * |
Jeff Layton | 90f7d7a | 2021-09-10 15:36:29 -0400 | [diff] [blame] | 2059 | * %LOCK_MAND support has been removed from the kernel. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2060 | */ |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 2061 | SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2062 | { |
Kuniyuki Iwashima | db4abb4 | 2022-07-16 21:35:32 -0700 | [diff] [blame] | 2063 | int can_sleep, error, type; |
Kuniyuki Iwashima | 4149be7 | 2022-07-16 21:35:31 -0700 | [diff] [blame] | 2064 | struct file_lock fl; |
Kuniyuki Iwashima | db4abb4 | 2022-07-16 21:35:32 -0700 | [diff] [blame] | 2065 | struct fd f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2066 | |
Jeff Layton | 90f7d7a | 2021-09-10 15:36:29 -0400 | [diff] [blame] | 2067 | /* |
| 2068 | * LOCK_MAND locks were broken for a long time in that they never |
| 2069 | * conflicted with one another and didn't prevent any sort of open, |
| 2070 | * read or write activity. |
| 2071 | * |
| 2072 | * Just ignore these requests now, to preserve legacy behavior, but |
| 2073 | * throw a warning to let people know that they don't actually work. |
| 2074 | */ |
| 2075 | if (cmd & LOCK_MAND) { |
Andi Kleen | f2f2494c | 2022-11-18 15:43:57 -0800 | [diff] [blame] | 2076 | pr_warn_once("%s(%d): Attempt to set a LOCK_MAND lock via flock(2). This support has been removed and the request ignored.\n", current->comm, current->pid); |
Kuniyuki Iwashima | db4abb4 | 2022-07-16 21:35:32 -0700 | [diff] [blame] | 2077 | return 0; |
Jeff Layton | 90f7d7a | 2021-09-10 15:36:29 -0400 | [diff] [blame] | 2078 | } |
| 2079 | |
Kuniyuki Iwashima | db4abb4 | 2022-07-16 21:35:32 -0700 | [diff] [blame] | 2080 | type = flock_translate_cmd(cmd & ~LOCK_NB); |
| 2081 | if (type < 0) |
| 2082 | return type; |
| 2083 | |
| 2084 | error = -EBADF; |
| 2085 | f = fdget(fd); |
| 2086 | if (!f.file) |
| 2087 | return error; |
| 2088 | |
| 2089 | if (type != F_UNLCK && !(f.file->f_mode & (FMODE_READ | FMODE_WRITE))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2090 | goto out_putf; |
Jeff Layton | 6e129d00 | 2014-09-04 10:25:06 -0400 | [diff] [blame] | 2091 | |
Kuniyuki Iwashima | 4149be7 | 2022-07-16 21:35:31 -0700 | [diff] [blame] | 2092 | flock_make_lock(f.file, &fl, type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2093 | |
Kuniyuki Iwashima | 4149be7 | 2022-07-16 21:35:31 -0700 | [diff] [blame] | 2094 | error = security_file_lock(f.file, fl.fl_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2095 | if (error) |
Kuniyuki Iwashima | 4149be7 | 2022-07-16 21:35:31 -0700 | [diff] [blame] | 2096 | goto out_putf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2097 | |
Kuniyuki Iwashima | db4abb4 | 2022-07-16 21:35:32 -0700 | [diff] [blame] | 2098 | can_sleep = !(cmd & LOCK_NB); |
| 2099 | if (can_sleep) |
| 2100 | fl.fl_flags |= FL_SLEEP; |
| 2101 | |
Miklos Szeredi | de2a4a5 | 2018-07-18 15:44:43 +0200 | [diff] [blame] | 2102 | if (f.file->f_op->flock) |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 2103 | error = f.file->f_op->flock(f.file, |
Kuniyuki Iwashima | db4abb4 | 2022-07-16 21:35:32 -0700 | [diff] [blame] | 2104 | (can_sleep) ? F_SETLKW : F_SETLK, |
Kuniyuki Iwashima | 4149be7 | 2022-07-16 21:35:31 -0700 | [diff] [blame] | 2105 | &fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2106 | else |
Kuniyuki Iwashima | 4149be7 | 2022-07-16 21:35:31 -0700 | [diff] [blame] | 2107 | error = locks_lock_file_wait(f.file, &fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2108 | |
David Howells | 932c29a | 2022-08-17 19:41:27 +0100 | [diff] [blame] | 2109 | locks_release_private(&fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2110 | out_putf: |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 2111 | fdput(f); |
Kuniyuki Iwashima | db4abb4 | 2022-07-16 21:35:32 -0700 | [diff] [blame] | 2112 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2113 | return error; |
| 2114 | } |
| 2115 | |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2116 | /** |
| 2117 | * vfs_test_lock - test file byte range lock |
| 2118 | * @filp: The file to test lock for |
J. Bruce Fields | 6924c55 | 2007-05-11 16:22:50 -0400 | [diff] [blame] | 2119 | * @fl: The lock to test; also used to hold result |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2120 | * |
| 2121 | * Returns -ERRNO on failure. Indicates presence of conflicting lock by |
| 2122 | * setting conf->fl_type to something other than F_UNLCK. |
| 2123 | */ |
| 2124 | int vfs_test_lock(struct file *filp, struct file_lock *fl) |
| 2125 | { |
Jeff Layton | 7e8e5cc8 | 2022-11-11 06:46:52 -0500 | [diff] [blame] | 2126 | WARN_ON_ONCE(filp != fl->fl_file); |
Miklos Szeredi | de2a4a5 | 2018-07-18 15:44:43 +0200 | [diff] [blame] | 2127 | if (filp->f_op->lock) |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2128 | return filp->f_op->lock(filp, F_GETLK, fl); |
| 2129 | posix_test_lock(filp, fl); |
| 2130 | return 0; |
| 2131 | } |
| 2132 | EXPORT_SYMBOL_GPL(vfs_test_lock); |
| 2133 | |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame] | 2134 | /** |
| 2135 | * locks_translate_pid - translate a file_lock's fl_pid number into a namespace |
| 2136 | * @fl: The file_lock who's fl_pid should be translated |
| 2137 | * @ns: The namespace into which the pid should be translated |
| 2138 | * |
| 2139 | * Used to tranlate a fl_pid into a namespace virtual pid number |
| 2140 | */ |
| 2141 | static pid_t locks_translate_pid(struct file_lock *fl, struct pid_namespace *ns) |
| 2142 | { |
| 2143 | pid_t vnr; |
| 2144 | struct pid *pid; |
| 2145 | |
| 2146 | if (IS_OFDLCK(fl)) |
| 2147 | return -1; |
| 2148 | if (IS_REMOTELCK(fl)) |
| 2149 | return fl->fl_pid; |
Konstantin Khorenko | 826d7bc | 2018-06-08 17:27:11 +0300 | [diff] [blame] | 2150 | /* |
| 2151 | * If the flock owner process is dead and its pid has been already |
| 2152 | * freed, the translation below won't work, but we still want to show |
| 2153 | * flock owner pid number in init pidns. |
| 2154 | */ |
| 2155 | if (ns == &init_pid_ns) |
| 2156 | return (pid_t)fl->fl_pid; |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame] | 2157 | |
| 2158 | rcu_read_lock(); |
| 2159 | pid = find_pid_ns(fl->fl_pid, &init_pid_ns); |
| 2160 | vnr = pid_nr_ns(pid, ns); |
| 2161 | rcu_read_unlock(); |
| 2162 | return vnr; |
| 2163 | } |
| 2164 | |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2165 | static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) |
| 2166 | { |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame] | 2167 | flock->l_pid = locks_translate_pid(fl, task_active_pid_ns(current)); |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2168 | #if BITS_PER_LONG == 32 |
| 2169 | /* |
| 2170 | * Make sure we can represent the posix lock via |
| 2171 | * legacy 32bit flock. |
| 2172 | */ |
| 2173 | if (fl->fl_start > OFFT_OFFSET_MAX) |
| 2174 | return -EOVERFLOW; |
| 2175 | if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX) |
| 2176 | return -EOVERFLOW; |
| 2177 | #endif |
| 2178 | flock->l_start = fl->fl_start; |
| 2179 | flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : |
| 2180 | fl->fl_end - fl->fl_start + 1; |
| 2181 | flock->l_whence = 0; |
J. Bruce Fields | 129a84d | 2007-05-10 18:38:43 -0400 | [diff] [blame] | 2182 | flock->l_type = fl->fl_type; |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2183 | return 0; |
| 2184 | } |
| 2185 | |
| 2186 | #if BITS_PER_LONG == 32 |
| 2187 | static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) |
| 2188 | { |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame] | 2189 | flock->l_pid = locks_translate_pid(fl, task_active_pid_ns(current)); |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2190 | flock->l_start = fl->fl_start; |
| 2191 | flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : |
| 2192 | fl->fl_end - fl->fl_start + 1; |
| 2193 | flock->l_whence = 0; |
| 2194 | flock->l_type = fl->fl_type; |
| 2195 | } |
| 2196 | #endif |
| 2197 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2198 | /* Report the first existing lock that would conflict with l. |
| 2199 | * This implements the F_GETLK command of fcntl(). |
| 2200 | */ |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2201 | int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2202 | { |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2203 | struct file_lock *fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2204 | int error; |
| 2205 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2206 | fl = locks_alloc_lock(); |
| 2207 | if (fl == NULL) |
| 2208 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2209 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2210 | if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2211 | goto out; |
| 2212 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2213 | error = flock_to_posix_lock(filp, fl, flock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2214 | if (error) |
| 2215 | goto out; |
| 2216 | |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2217 | if (cmd == F_OFD_GETLK) { |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2218 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2219 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2220 | goto out; |
| 2221 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2222 | fl->fl_flags |= FL_OFDLCK; |
| 2223 | fl->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2224 | } |
| 2225 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2226 | error = vfs_test_lock(filp, fl); |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2227 | if (error) |
| 2228 | goto out; |
NeilBrown | 7bbd1fc | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 2229 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2230 | flock->l_type = fl->fl_type; |
| 2231 | if (fl->fl_type != F_UNLCK) { |
| 2232 | error = posix_lock_to_flock(flock, fl); |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2233 | if (error) |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2234 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2235 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2236 | out: |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2237 | locks_free_lock(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2238 | return error; |
| 2239 | } |
| 2240 | |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2241 | /** |
| 2242 | * vfs_lock_file - file byte range lock |
| 2243 | * @filp: The file to apply the lock to |
| 2244 | * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.) |
| 2245 | * @fl: The lock to be applied |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 2246 | * @conf: Place to return a copy of the conflicting lock, if found. |
| 2247 | * |
| 2248 | * A caller that doesn't care about the conflicting lock may pass NULL |
| 2249 | * as the final argument. |
| 2250 | * |
| 2251 | * If the filesystem defines a private ->lock() method, then @conf will |
| 2252 | * be left unchanged; so a caller that cares should initialize it to |
| 2253 | * some acceptable default. |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2254 | * |
| 2255 | * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX |
| 2256 | * locks, the ->lock() interface may return asynchronously, before the lock has |
| 2257 | * been granted or denied by the underlying filesystem, if (and only if) |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 2258 | * lm_grant is set. Callers expecting ->lock() to return asynchronously |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2259 | * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) |
| 2260 | * the request is for a blocking lock. When ->lock() does return asynchronously, |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 2261 | * it must return FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2262 | * request completes. |
| 2263 | * If the request is for non-blocking lock the file system should return |
Miklos Szeredi | bde74e4 | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2264 | * FILE_LOCK_DEFERRED then try to get the lock and call the callback routine |
| 2265 | * with the result. If the request timed out the callback routine will return a |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2266 | * nonzero return code and the file system should release the lock. The file |
| 2267 | * system is also responsible to keep a corresponding posix lock when it |
| 2268 | * grants a lock so the VFS can find out which locks are locally held and do |
| 2269 | * the correct lock cleanup when required. |
| 2270 | * The underlying filesystem must not drop the kernel lock or call |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 2271 | * ->lm_grant() before returning to the caller with a FILE_LOCK_DEFERRED |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2272 | * return code. |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2273 | */ |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 2274 | int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf) |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2275 | { |
Jeff Layton | 7e8e5cc8 | 2022-11-11 06:46:52 -0500 | [diff] [blame] | 2276 | WARN_ON_ONCE(filp != fl->fl_file); |
Miklos Szeredi | de2a4a5 | 2018-07-18 15:44:43 +0200 | [diff] [blame] | 2277 | if (filp->f_op->lock) |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2278 | return filp->f_op->lock(filp, cmd, fl); |
| 2279 | else |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 2280 | return posix_lock_file(filp, fl, conf); |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2281 | } |
| 2282 | EXPORT_SYMBOL_GPL(vfs_lock_file); |
| 2283 | |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2284 | static int do_lock_file_wait(struct file *filp, unsigned int cmd, |
| 2285 | struct file_lock *fl) |
| 2286 | { |
| 2287 | int error; |
| 2288 | |
| 2289 | error = security_file_lock(filp, fl->fl_type); |
| 2290 | if (error) |
| 2291 | return error; |
| 2292 | |
Miklos Szeredi | 764c76b | 2008-07-25 01:48:58 -0700 | [diff] [blame] | 2293 | for (;;) { |
| 2294 | error = vfs_lock_file(filp, cmd, fl, NULL); |
| 2295 | if (error != FILE_LOCK_DEFERRED) |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2296 | break; |
Linus Torvalds | dcf23ac | 2020-03-18 07:52:21 -0400 | [diff] [blame] | 2297 | error = wait_event_interruptible(fl->fl_wait, |
| 2298 | list_empty(&fl->fl_blocked_member)); |
NeilBrown | 16306a6 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 2299 | if (error) |
| 2300 | break; |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2301 | } |
NeilBrown | 16306a6 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 2302 | locks_delete_block(fl); |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2303 | |
| 2304 | return error; |
| 2305 | } |
| 2306 | |
Benjamin Coddington | 6ca7d91 | 2015-10-15 09:07:07 -0400 | [diff] [blame] | 2307 | /* Ensure that fl->fl_file has compatible f_mode for F_SETLK calls */ |
Jeff Layton | cf01f4e | 2014-05-09 11:41:54 -0400 | [diff] [blame] | 2308 | static int |
| 2309 | check_fmode_for_setlk(struct file_lock *fl) |
| 2310 | { |
| 2311 | switch (fl->fl_type) { |
| 2312 | case F_RDLCK: |
| 2313 | if (!(fl->fl_file->f_mode & FMODE_READ)) |
| 2314 | return -EBADF; |
| 2315 | break; |
| 2316 | case F_WRLCK: |
| 2317 | if (!(fl->fl_file->f_mode & FMODE_WRITE)) |
| 2318 | return -EBADF; |
| 2319 | } |
| 2320 | return 0; |
| 2321 | } |
| 2322 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2323 | /* Apply the lock described by l to an open file descriptor. |
| 2324 | * This implements both the F_SETLK and F_SETLKW commands of fcntl(). |
| 2325 | */ |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2326 | int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2327 | struct flock *flock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2328 | { |
| 2329 | struct file_lock *file_lock = locks_alloc_lock(); |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 2330 | struct inode *inode = file_inode(filp); |
Al Viro | 0b2bac2 | 2008-05-06 13:58:34 -0400 | [diff] [blame] | 2331 | struct file *f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2332 | int error; |
| 2333 | |
| 2334 | if (file_lock == NULL) |
| 2335 | return -ENOLCK; |
| 2336 | |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2337 | error = flock_to_posix_lock(filp, file_lock, flock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2338 | if (error) |
| 2339 | goto out; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2340 | |
Jeff Layton | cf01f4e | 2014-05-09 11:41:54 -0400 | [diff] [blame] | 2341 | error = check_fmode_for_setlk(file_lock); |
| 2342 | if (error) |
| 2343 | goto out; |
| 2344 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2345 | /* |
| 2346 | * If the cmd is requesting file-private locks, then set the |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2347 | * FL_OFDLCK flag and override the owner. |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2348 | */ |
| 2349 | switch (cmd) { |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2350 | case F_OFD_SETLK: |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2351 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2352 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2353 | goto out; |
| 2354 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2355 | cmd = F_SETLK; |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2356 | file_lock->fl_flags |= FL_OFDLCK; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2357 | file_lock->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2358 | break; |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2359 | case F_OFD_SETLKW: |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2360 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2361 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2362 | goto out; |
| 2363 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2364 | cmd = F_SETLKW; |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2365 | file_lock->fl_flags |= FL_OFDLCK; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2366 | file_lock->fl_owner = filp; |
Gustavo A. R. Silva | df561f66 | 2020-08-23 17:36:59 -0500 | [diff] [blame] | 2367 | fallthrough; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2368 | case F_SETLKW: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2369 | file_lock->fl_flags |= FL_SLEEP; |
| 2370 | } |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2371 | |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2372 | error = do_lock_file_wait(filp, cmd, file_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2373 | |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2374 | /* |
Jeff Layton | 0752ba80 | 2016-01-08 07:30:43 -0500 | [diff] [blame] | 2375 | * Attempt to detect a close/fcntl race and recover by releasing the |
| 2376 | * lock that was just acquired. There is no need to do that when we're |
| 2377 | * unlocking though, or for OFD locks. |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2378 | */ |
Jeff Layton | 0752ba80 | 2016-01-08 07:30:43 -0500 | [diff] [blame] | 2379 | if (!error && file_lock->fl_type != F_UNLCK && |
| 2380 | !(file_lock->fl_flags & FL_OFDLCK)) { |
Eric W. Biederman | 120ce2b | 2020-11-20 17:14:25 -0600 | [diff] [blame] | 2381 | struct files_struct *files = current->files; |
Jeff Layton | 7f3697e | 2016-01-07 16:38:10 -0500 | [diff] [blame] | 2382 | /* |
| 2383 | * We need that spin_lock here - it prevents reordering between |
| 2384 | * update of i_flctx->flc_posix and check for it done in |
| 2385 | * close(). rcu_read_lock() wouldn't do. |
| 2386 | */ |
Eric W. Biederman | 120ce2b | 2020-11-20 17:14:25 -0600 | [diff] [blame] | 2387 | spin_lock(&files->file_lock); |
| 2388 | f = files_lookup_fd_locked(files, fd); |
| 2389 | spin_unlock(&files->file_lock); |
Jeff Layton | 7f3697e | 2016-01-07 16:38:10 -0500 | [diff] [blame] | 2390 | if (f != filp) { |
| 2391 | file_lock->fl_type = F_UNLCK; |
| 2392 | error = do_lock_file_wait(filp, cmd, file_lock); |
| 2393 | WARN_ON_ONCE(error); |
| 2394 | error = -EBADF; |
| 2395 | } |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2396 | } |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2397 | out: |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 2398 | trace_fcntl_setlk(inode, file_lock, error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2399 | locks_free_lock(file_lock); |
| 2400 | return error; |
| 2401 | } |
| 2402 | |
| 2403 | #if BITS_PER_LONG == 32 |
| 2404 | /* Report the first existing lock that would conflict with l. |
| 2405 | * This implements the F_GETLK command of fcntl(). |
| 2406 | */ |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2407 | int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 *flock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2408 | { |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2409 | struct file_lock *fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2410 | int error; |
| 2411 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2412 | fl = locks_alloc_lock(); |
| 2413 | if (fl == NULL) |
| 2414 | return -ENOMEM; |
| 2415 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2416 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2417 | if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2418 | goto out; |
| 2419 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2420 | error = flock64_to_posix_lock(filp, fl, flock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2421 | if (error) |
| 2422 | goto out; |
| 2423 | |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2424 | if (cmd == F_OFD_GETLK) { |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2425 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2426 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2427 | goto out; |
| 2428 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2429 | fl->fl_flags |= FL_OFDLCK; |
| 2430 | fl->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2431 | } |
| 2432 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2433 | error = vfs_test_lock(filp, fl); |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2434 | if (error) |
| 2435 | goto out; |
| 2436 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2437 | flock->l_type = fl->fl_type; |
| 2438 | if (fl->fl_type != F_UNLCK) |
| 2439 | posix_lock_to_flock64(flock, fl); |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 2440 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2441 | out: |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2442 | locks_free_lock(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2443 | return error; |
| 2444 | } |
| 2445 | |
| 2446 | /* Apply the lock described by l to an open file descriptor. |
| 2447 | * This implements both the F_SETLK and F_SETLKW commands of fcntl(). |
| 2448 | */ |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2449 | int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2450 | struct flock64 *flock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2451 | { |
| 2452 | struct file_lock *file_lock = locks_alloc_lock(); |
Al Viro | 0b2bac2 | 2008-05-06 13:58:34 -0400 | [diff] [blame] | 2453 | struct file *f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2454 | int error; |
| 2455 | |
| 2456 | if (file_lock == NULL) |
| 2457 | return -ENOLCK; |
| 2458 | |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2459 | error = flock64_to_posix_lock(filp, file_lock, flock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2460 | if (error) |
| 2461 | goto out; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2462 | |
Jeff Layton | cf01f4e | 2014-05-09 11:41:54 -0400 | [diff] [blame] | 2463 | error = check_fmode_for_setlk(file_lock); |
| 2464 | if (error) |
| 2465 | goto out; |
| 2466 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2467 | /* |
| 2468 | * If the cmd is requesting file-private locks, then set the |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2469 | * FL_OFDLCK flag and override the owner. |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2470 | */ |
| 2471 | switch (cmd) { |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2472 | case F_OFD_SETLK: |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2473 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2474 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2475 | goto out; |
| 2476 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2477 | cmd = F_SETLK64; |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2478 | file_lock->fl_flags |= FL_OFDLCK; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2479 | file_lock->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2480 | break; |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2481 | case F_OFD_SETLKW: |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2482 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2483 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2484 | goto out; |
| 2485 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2486 | cmd = F_SETLKW64; |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2487 | file_lock->fl_flags |= FL_OFDLCK; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2488 | file_lock->fl_owner = filp; |
Gustavo A. R. Silva | df561f66 | 2020-08-23 17:36:59 -0500 | [diff] [blame] | 2489 | fallthrough; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2490 | case F_SETLKW64: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2491 | file_lock->fl_flags |= FL_SLEEP; |
| 2492 | } |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2493 | |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2494 | error = do_lock_file_wait(filp, cmd, file_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2495 | |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2496 | /* |
Jeff Layton | 0752ba80 | 2016-01-08 07:30:43 -0500 | [diff] [blame] | 2497 | * Attempt to detect a close/fcntl race and recover by releasing the |
| 2498 | * lock that was just acquired. There is no need to do that when we're |
| 2499 | * unlocking though, or for OFD locks. |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2500 | */ |
Jeff Layton | 0752ba80 | 2016-01-08 07:30:43 -0500 | [diff] [blame] | 2501 | if (!error && file_lock->fl_type != F_UNLCK && |
| 2502 | !(file_lock->fl_flags & FL_OFDLCK)) { |
Eric W. Biederman | 120ce2b | 2020-11-20 17:14:25 -0600 | [diff] [blame] | 2503 | struct files_struct *files = current->files; |
Jeff Layton | 7f3697e | 2016-01-07 16:38:10 -0500 | [diff] [blame] | 2504 | /* |
| 2505 | * We need that spin_lock here - it prevents reordering between |
| 2506 | * update of i_flctx->flc_posix and check for it done in |
| 2507 | * close(). rcu_read_lock() wouldn't do. |
| 2508 | */ |
Eric W. Biederman | 120ce2b | 2020-11-20 17:14:25 -0600 | [diff] [blame] | 2509 | spin_lock(&files->file_lock); |
| 2510 | f = files_lookup_fd_locked(files, fd); |
| 2511 | spin_unlock(&files->file_lock); |
Jeff Layton | 7f3697e | 2016-01-07 16:38:10 -0500 | [diff] [blame] | 2512 | if (f != filp) { |
| 2513 | file_lock->fl_type = F_UNLCK; |
| 2514 | error = do_lock_file_wait(filp, cmd, file_lock); |
| 2515 | WARN_ON_ONCE(error); |
| 2516 | error = -EBADF; |
| 2517 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2518 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2519 | out: |
| 2520 | locks_free_lock(file_lock); |
| 2521 | return error; |
| 2522 | } |
| 2523 | #endif /* BITS_PER_LONG == 32 */ |
| 2524 | |
| 2525 | /* |
| 2526 | * This function is called when the file is being removed |
| 2527 | * from the task's fd array. POSIX locks belonging to this task |
| 2528 | * are deleted at this time. |
| 2529 | */ |
| 2530 | void locks_remove_posix(struct file *filp, fl_owner_t owner) |
| 2531 | { |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 2532 | int error; |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 2533 | struct inode *inode = file_inode(filp); |
Miklos Szeredi | ff7b86b | 2006-06-23 02:05:11 -0700 | [diff] [blame] | 2534 | struct file_lock lock; |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2535 | struct file_lock_context *ctx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2536 | |
| 2537 | /* |
| 2538 | * If there are no locks held on this file, we don't need to call |
| 2539 | * posix_lock_file(). Another process could be setting a lock on this |
| 2540 | * file at the same time, but we wouldn't remove that lock anyway. |
| 2541 | */ |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 2542 | ctx = locks_inode_context(inode); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2543 | if (!ctx || list_empty(&ctx->flc_posix)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2544 | return; |
| 2545 | |
NeilBrown | d6367d6 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 2546 | locks_init_lock(&lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2547 | lock.fl_type = F_UNLCK; |
Miklos Szeredi | 75e1fcc | 2006-06-23 02:05:12 -0700 | [diff] [blame] | 2548 | lock.fl_flags = FL_POSIX | FL_CLOSE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2549 | lock.fl_start = 0; |
| 2550 | lock.fl_end = OFFSET_MAX; |
| 2551 | lock.fl_owner = owner; |
| 2552 | lock.fl_pid = current->tgid; |
| 2553 | lock.fl_file = filp; |
| 2554 | lock.fl_ops = NULL; |
| 2555 | lock.fl_lmops = NULL; |
| 2556 | |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 2557 | error = vfs_lock_file(filp, F_SETLK, &lock, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2558 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2559 | if (lock.fl_ops && lock.fl_ops->fl_release_private) |
| 2560 | lock.fl_ops->fl_release_private(&lock); |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2561 | trace_locks_remove_posix(inode, &lock, error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2562 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2563 | EXPORT_SYMBOL(locks_remove_posix); |
| 2564 | |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2565 | /* The i_flctx must be valid when calling into here */ |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2566 | static void |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2567 | locks_remove_flock(struct file *filp, struct file_lock_context *flctx) |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2568 | { |
NeilBrown | d6367d6 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 2569 | struct file_lock fl; |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 2570 | struct inode *inode = file_inode(filp); |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2571 | |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2572 | if (list_empty(&flctx->flc_flock)) |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2573 | return; |
| 2574 | |
Kuniyuki Iwashima | 4149be7 | 2022-07-16 21:35:31 -0700 | [diff] [blame] | 2575 | flock_make_lock(filp, &fl, F_UNLCK); |
NeilBrown | d6367d6 | 2018-11-30 10:04:08 +1100 | [diff] [blame] | 2576 | fl.fl_flags |= FL_CLOSE; |
| 2577 | |
Miklos Szeredi | de2a4a5 | 2018-07-18 15:44:43 +0200 | [diff] [blame] | 2578 | if (filp->f_op->flock) |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2579 | filp->f_op->flock(filp, F_SETLKW, &fl); |
| 2580 | else |
Jeff Layton | bcd7f78d | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 2581 | flock_lock_inode(inode, &fl); |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2582 | |
| 2583 | if (fl.fl_ops && fl.fl_ops->fl_release_private) |
| 2584 | fl.fl_ops->fl_release_private(&fl); |
| 2585 | } |
| 2586 | |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2587 | /* The i_flctx must be valid when calling into here */ |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2588 | static void |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2589 | locks_remove_lease(struct file *filp, struct file_lock_context *ctx) |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2590 | { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2591 | struct file_lock *fl, *tmp; |
| 2592 | LIST_HEAD(dispose); |
| 2593 | |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2594 | if (list_empty(&ctx->flc_lease)) |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2595 | return; |
| 2596 | |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 2597 | percpu_down_read(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 2598 | spin_lock(&ctx->flc_lock); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2599 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) |
Jeff Layton | c4e136c | 2015-02-16 19:37:42 -0500 | [diff] [blame] | 2600 | if (filp == fl->fl_file) |
| 2601 | lease_modify(fl, F_UNLCK, &dispose); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 2602 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 02e525b2 | 2019-02-21 15:38:40 +0100 | [diff] [blame] | 2603 | percpu_up_read(&file_rwsem); |
Peter Zijlstra | 5f43086 | 2016-10-08 10:12:28 +0200 | [diff] [blame] | 2604 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2605 | locks_dispose_list(&dispose); |
| 2606 | } |
| 2607 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2608 | /* |
| 2609 | * This function is called on the last close of an open file. |
| 2610 | */ |
Jeff Layton | 78ed8a1 | 2014-02-03 12:13:08 -0500 | [diff] [blame] | 2611 | void locks_remove_file(struct file *filp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2612 | { |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2613 | struct file_lock_context *ctx; |
| 2614 | |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 2615 | ctx = locks_inode_context(file_inode(filp)); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2616 | if (!ctx) |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2617 | return; |
| 2618 | |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2619 | /* remove any OFD locks */ |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2620 | locks_remove_posix(filp, filp); |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2621 | |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2622 | /* remove flock locks */ |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2623 | locks_remove_flock(filp, ctx); |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2624 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2625 | /* remove any leases */ |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2626 | locks_remove_lease(filp, ctx); |
Benjamin Coddington | 3953704 | 2017-07-21 13:36:25 -0400 | [diff] [blame] | 2627 | |
| 2628 | spin_lock(&ctx->flc_lock); |
| 2629 | locks_check_ctx_file_list(filp, &ctx->flc_posix, "POSIX"); |
| 2630 | locks_check_ctx_file_list(filp, &ctx->flc_flock, "FLOCK"); |
| 2631 | locks_check_ctx_file_list(filp, &ctx->flc_lease, "LEASE"); |
| 2632 | spin_unlock(&ctx->flc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2633 | } |
| 2634 | |
| 2635 | /** |
Marc Eshel | 9b9d2ab | 2007-01-18 17:52:58 -0500 | [diff] [blame] | 2636 | * vfs_cancel_lock - file byte range unblock lock |
| 2637 | * @filp: The file to apply the unblock to |
| 2638 | * @fl: The lock to be unblocked |
| 2639 | * |
| 2640 | * Used by lock managers to cancel blocked requests |
| 2641 | */ |
| 2642 | int vfs_cancel_lock(struct file *filp, struct file_lock *fl) |
| 2643 | { |
Jeff Layton | 7e8e5cc8 | 2022-11-11 06:46:52 -0500 | [diff] [blame] | 2644 | WARN_ON_ONCE(filp != fl->fl_file); |
Miklos Szeredi | de2a4a5 | 2018-07-18 15:44:43 +0200 | [diff] [blame] | 2645 | if (filp->f_op->lock) |
Marc Eshel | 9b9d2ab | 2007-01-18 17:52:58 -0500 | [diff] [blame] | 2646 | return filp->f_op->lock(filp, F_CANCELLK, fl); |
| 2647 | return 0; |
| 2648 | } |
Marc Eshel | 9b9d2ab | 2007-01-18 17:52:58 -0500 | [diff] [blame] | 2649 | EXPORT_SYMBOL_GPL(vfs_cancel_lock); |
| 2650 | |
Jeff Layton | ab1ddef | 2022-11-14 08:33:09 -0500 | [diff] [blame] | 2651 | /** |
| 2652 | * vfs_inode_has_locks - are any file locks held on @inode? |
| 2653 | * @inode: inode to check for locks |
| 2654 | * |
| 2655 | * Return true if there are any FL_POSIX or FL_FLOCK locks currently |
| 2656 | * set on @inode. |
| 2657 | */ |
| 2658 | bool vfs_inode_has_locks(struct inode *inode) |
| 2659 | { |
| 2660 | struct file_lock_context *ctx; |
| 2661 | bool ret; |
| 2662 | |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 2663 | ctx = locks_inode_context(inode); |
Jeff Layton | ab1ddef | 2022-11-14 08:33:09 -0500 | [diff] [blame] | 2664 | if (!ctx) |
| 2665 | return false; |
| 2666 | |
| 2667 | spin_lock(&ctx->flc_lock); |
| 2668 | ret = !list_empty(&ctx->flc_posix) || !list_empty(&ctx->flc_flock); |
| 2669 | spin_unlock(&ctx->flc_lock); |
| 2670 | return ret; |
| 2671 | } |
| 2672 | EXPORT_SYMBOL_GPL(vfs_inode_has_locks); |
| 2673 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2674 | #ifdef CONFIG_PROC_FS |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2675 | #include <linux/proc_fs.h> |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2676 | #include <linux/seq_file.h> |
| 2677 | |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2678 | struct locks_iterator { |
| 2679 | int li_cpu; |
| 2680 | loff_t li_pos; |
| 2681 | }; |
| 2682 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2683 | static void lock_get_status(struct seq_file *f, struct file_lock *fl, |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2684 | loff_t id, char *pfx, int repeat) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2685 | { |
| 2686 | struct inode *inode = NULL; |
Vitaliy Gusev | ab1f161 | 2008-01-17 00:07:08 +0000 | [diff] [blame] | 2687 | unsigned int fl_pid; |
Alexey Gladkov | 9d78ede | 2020-05-18 20:07:38 +0200 | [diff] [blame] | 2688 | struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb); |
Jeff Layton | 90f7d7a | 2021-09-10 15:36:29 -0400 | [diff] [blame] | 2689 | int type; |
Vitaliy Gusev | ab1f161 | 2008-01-17 00:07:08 +0000 | [diff] [blame] | 2690 | |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame] | 2691 | fl_pid = locks_translate_pid(fl, proc_pidns); |
| 2692 | /* |
Konstantin Khorenko | 1cf8e5d | 2018-06-08 17:27:12 +0300 | [diff] [blame] | 2693 | * If lock owner is dead (and pid is freed) or not visible in current |
| 2694 | * pidns, zero is shown as a pid value. Check lock info from |
| 2695 | * init_pid_ns to get saved lock pid value. |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame] | 2696 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2697 | |
| 2698 | if (fl->fl_file != NULL) |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 2699 | inode = file_inode(fl->fl_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2700 | |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2701 | seq_printf(f, "%lld: ", id); |
| 2702 | |
| 2703 | if (repeat) |
| 2704 | seq_printf(f, "%*s", repeat - 1 + (int)strlen(pfx), pfx); |
| 2705 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2706 | if (IS_POSIX(fl)) { |
Jeff Layton | c918d42 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 2707 | if (fl->fl_flags & FL_ACCESS) |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2708 | seq_puts(f, "ACCESS"); |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2709 | else if (IS_OFDLCK(fl)) |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2710 | seq_puts(f, "OFDLCK"); |
Jeff Layton | c918d42 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 2711 | else |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2712 | seq_puts(f, "POSIX "); |
Jeff Layton | c918d42 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 2713 | |
| 2714 | seq_printf(f, " %s ", |
Jeff Layton | f7e33bd | 2021-08-19 14:56:38 -0400 | [diff] [blame] | 2715 | (inode == NULL) ? "*NOINODE*" : "ADVISORY "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2716 | } else if (IS_FLOCK(fl)) { |
Jeff Layton | 90f7d7a | 2021-09-10 15:36:29 -0400 | [diff] [blame] | 2717 | seq_puts(f, "FLOCK ADVISORY "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2718 | } else if (IS_LEASE(fl)) { |
Jeff Layton | 8144f1f | 2014-08-11 13:36:54 -0400 | [diff] [blame] | 2719 | if (fl->fl_flags & FL_DELEG) |
| 2720 | seq_puts(f, "DELEG "); |
| 2721 | else |
| 2722 | seq_puts(f, "LEASE "); |
| 2723 | |
J. Bruce Fields | ab83fa4 | 2011-07-26 20:10:51 -0400 | [diff] [blame] | 2724 | if (lease_breaking(fl)) |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2725 | seq_puts(f, "BREAKING "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2726 | else if (fl->fl_file) |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2727 | seq_puts(f, "ACTIVE "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2728 | else |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2729 | seq_puts(f, "BREAKER "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2730 | } else { |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2731 | seq_puts(f, "UNKNOWN UNKNOWN "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2732 | } |
Jeff Layton | 90f7d7a | 2021-09-10 15:36:29 -0400 | [diff] [blame] | 2733 | type = IS_LEASE(fl) ? target_leasetype(fl) : fl->fl_type; |
Pavel Begunkov | 43e4cb9 | 2019-07-24 20:16:31 +0300 | [diff] [blame] | 2734 | |
Jeff Layton | 90f7d7a | 2021-09-10 15:36:29 -0400 | [diff] [blame] | 2735 | seq_printf(f, "%s ", (type == F_WRLCK) ? "WRITE" : |
| 2736 | (type == F_RDLCK) ? "READ" : "UNLCK"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2737 | if (inode) { |
Jeff Layton | 3648888 | 2015-04-03 09:04:04 -0400 | [diff] [blame] | 2738 | /* userspace relies on this representation of dev_t */ |
Amir Goldstein | 98ca480 | 2019-12-22 20:45:28 +0200 | [diff] [blame] | 2739 | seq_printf(f, "%d %02x:%02x:%lu ", fl_pid, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2740 | MAJOR(inode->i_sb->s_dev), |
| 2741 | MINOR(inode->i_sb->s_dev), inode->i_ino); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2742 | } else { |
Vitaliy Gusev | ab1f161 | 2008-01-17 00:07:08 +0000 | [diff] [blame] | 2743 | seq_printf(f, "%d <none>:0 ", fl_pid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2744 | } |
| 2745 | if (IS_POSIX(fl)) { |
| 2746 | if (fl->fl_end == OFFSET_MAX) |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2747 | seq_printf(f, "%Ld EOF\n", fl->fl_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2748 | else |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2749 | seq_printf(f, "%Ld %Ld\n", fl->fl_start, fl->fl_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2750 | } else { |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2751 | seq_puts(f, "0 EOF\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2752 | } |
| 2753 | } |
| 2754 | |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2755 | static struct file_lock *get_next_blocked_member(struct file_lock *node) |
| 2756 | { |
| 2757 | struct file_lock *tmp; |
| 2758 | |
| 2759 | /* NULL node or root node */ |
| 2760 | if (node == NULL || node->fl_blocker == NULL) |
| 2761 | return NULL; |
| 2762 | |
| 2763 | /* Next member in the linked list could be itself */ |
| 2764 | tmp = list_next_entry(node, fl_blocked_member); |
| 2765 | if (list_entry_is_head(tmp, &node->fl_blocker->fl_blocked_requests, fl_blocked_member) |
| 2766 | || tmp == node) { |
| 2767 | return NULL; |
| 2768 | } |
| 2769 | |
| 2770 | return tmp; |
| 2771 | } |
| 2772 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2773 | static int locks_show(struct seq_file *f, void *v) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2774 | { |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2775 | struct locks_iterator *iter = f->private; |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2776 | struct file_lock *cur, *tmp; |
Alexey Gladkov | 9d78ede | 2020-05-18 20:07:38 +0200 | [diff] [blame] | 2777 | struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb); |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2778 | int level = 0; |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2779 | |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2780 | cur = hlist_entry(v, struct file_lock, fl_link); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2781 | |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2782 | if (locks_translate_pid(cur, proc_pidns) == 0) |
Nikolay Borisov | d67fd44 | 2016-08-17 16:18:46 -0400 | [diff] [blame] | 2783 | return 0; |
| 2784 | |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2785 | /* View this crossed linked list as a binary tree, the first member of fl_blocked_requests |
| 2786 | * is the left child of current node, the next silibing in fl_blocked_member is the |
| 2787 | * right child, we can alse get the parent of current node from fl_blocker, so this |
| 2788 | * question becomes traversal of a binary tree |
| 2789 | */ |
| 2790 | while (cur != NULL) { |
| 2791 | if (level) |
| 2792 | lock_get_status(f, cur, iter->li_pos, "-> ", level); |
| 2793 | else |
| 2794 | lock_get_status(f, cur, iter->li_pos, "", level); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2795 | |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2796 | if (!list_empty(&cur->fl_blocked_requests)) { |
| 2797 | /* Turn left */ |
| 2798 | cur = list_first_entry_or_null(&cur->fl_blocked_requests, |
| 2799 | struct file_lock, fl_blocked_member); |
| 2800 | level++; |
| 2801 | } else { |
| 2802 | /* Turn right */ |
| 2803 | tmp = get_next_blocked_member(cur); |
| 2804 | /* Fall back to parent node */ |
| 2805 | while (tmp == NULL && cur->fl_blocker != NULL) { |
| 2806 | cur = cur->fl_blocker; |
| 2807 | level--; |
| 2808 | tmp = get_next_blocked_member(cur); |
| 2809 | } |
| 2810 | cur = tmp; |
| 2811 | } |
| 2812 | } |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2813 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2814 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2815 | } |
| 2816 | |
Andrey Vagin | 6c8c903 | 2015-04-16 12:49:38 -0700 | [diff] [blame] | 2817 | static void __show_fd_locks(struct seq_file *f, |
| 2818 | struct list_head *head, int *id, |
| 2819 | struct file *filp, struct files_struct *files) |
| 2820 | { |
| 2821 | struct file_lock *fl; |
| 2822 | |
| 2823 | list_for_each_entry(fl, head, fl_list) { |
| 2824 | |
| 2825 | if (filp != fl->fl_file) |
| 2826 | continue; |
| 2827 | if (fl->fl_owner != files && |
| 2828 | fl->fl_owner != filp) |
| 2829 | continue; |
| 2830 | |
| 2831 | (*id)++; |
| 2832 | seq_puts(f, "lock:\t"); |
Luo Longjun | b8da9b1 | 2021-02-25 22:58:29 -0500 | [diff] [blame] | 2833 | lock_get_status(f, fl, *id, "", 0); |
Andrey Vagin | 6c8c903 | 2015-04-16 12:49:38 -0700 | [diff] [blame] | 2834 | } |
| 2835 | } |
| 2836 | |
| 2837 | void show_fd_locks(struct seq_file *f, |
| 2838 | struct file *filp, struct files_struct *files) |
| 2839 | { |
Jeff Layton | c65454a | 2022-11-25 08:48:37 -0500 | [diff] [blame] | 2840 | struct inode *inode = file_inode(filp); |
Andrey Vagin | 6c8c903 | 2015-04-16 12:49:38 -0700 | [diff] [blame] | 2841 | struct file_lock_context *ctx; |
| 2842 | int id = 0; |
| 2843 | |
Jeff Layton | 401a8b8 | 2022-11-16 09:02:30 -0500 | [diff] [blame] | 2844 | ctx = locks_inode_context(inode); |
Andrey Vagin | 6c8c903 | 2015-04-16 12:49:38 -0700 | [diff] [blame] | 2845 | if (!ctx) |
| 2846 | return; |
| 2847 | |
| 2848 | spin_lock(&ctx->flc_lock); |
| 2849 | __show_fd_locks(f, &ctx->flc_flock, &id, filp, files); |
| 2850 | __show_fd_locks(f, &ctx->flc_posix, &id, filp, files); |
| 2851 | __show_fd_locks(f, &ctx->flc_lease, &id, filp, files); |
| 2852 | spin_unlock(&ctx->flc_lock); |
| 2853 | } |
| 2854 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2855 | static void *locks_start(struct seq_file *f, loff_t *pos) |
Jeff Layton | b03dfdec | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 2856 | __acquires(&blocked_lock_lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2857 | { |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2858 | struct locks_iterator *iter = f->private; |
Jerome Marchand | 99dc829 | 2010-10-26 14:22:33 -0700 | [diff] [blame] | 2859 | |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2860 | iter->li_pos = *pos + 1; |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 2861 | percpu_down_write(&file_rwsem); |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 2862 | spin_lock(&blocked_lock_lock); |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 2863 | return seq_hlist_start_percpu(&file_lock_list.hlist, &iter->li_cpu, *pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2864 | } |
| 2865 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2866 | static void *locks_next(struct seq_file *f, void *v, loff_t *pos) |
| 2867 | { |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2868 | struct locks_iterator *iter = f->private; |
| 2869 | |
| 2870 | ++iter->li_pos; |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 2871 | return seq_hlist_next_percpu(v, &file_lock_list.hlist, &iter->li_cpu, pos); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2872 | } |
| 2873 | |
| 2874 | static void locks_stop(struct seq_file *f, void *v) |
Jeff Layton | b03dfdec | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 2875 | __releases(&blocked_lock_lock) |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2876 | { |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 2877 | spin_unlock(&blocked_lock_lock); |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 2878 | percpu_up_write(&file_rwsem); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2879 | } |
| 2880 | |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2881 | static const struct seq_operations locks_seq_operations = { |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2882 | .start = locks_start, |
| 2883 | .next = locks_next, |
| 2884 | .stop = locks_stop, |
| 2885 | .show = locks_show, |
| 2886 | }; |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2887 | |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2888 | static int __init proc_locks_init(void) |
| 2889 | { |
Christoph Hellwig | 44414d8 | 2018-04-24 17:05:17 +0200 | [diff] [blame] | 2890 | proc_create_seq_private("locks", 0, NULL, &locks_seq_operations, |
| 2891 | sizeof(struct locks_iterator), NULL); |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2892 | return 0; |
| 2893 | } |
Paul Gortmaker | 9189922 | 2015-12-17 14:11:03 -0500 | [diff] [blame] | 2894 | fs_initcall(proc_locks_init); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2895 | #endif |
| 2896 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2897 | static int __init filelock_init(void) |
| 2898 | { |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2899 | int i; |
| 2900 | |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2901 | flctx_cache = kmem_cache_create("file_lock_ctx", |
Linus Torvalds | 3754707 | 2021-09-07 11:21:48 -0700 | [diff] [blame] | 2902 | sizeof(struct file_lock_context), 0, SLAB_PANIC, NULL); |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2903 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2904 | filelock_cache = kmem_cache_create("file_lock_cache", |
Linus Torvalds | 3754707 | 2021-09-07 11:21:48 -0700 | [diff] [blame] | 2905 | sizeof(struct file_lock), 0, SLAB_PANIC, NULL); |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 2906 | |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 2907 | for_each_possible_cpu(i) { |
| 2908 | struct file_lock_list_struct *fll = per_cpu_ptr(&file_lock_list, i); |
| 2909 | |
| 2910 | spin_lock_init(&fll->lock); |
| 2911 | INIT_HLIST_HEAD(&fll->hlist); |
| 2912 | } |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2913 | |
Jeff Layton | 18f6622 | 2019-08-18 14:18:45 -0400 | [diff] [blame] | 2914 | lease_notifier_chain_init(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2915 | return 0; |
| 2916 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2917 | core_initcall(filelock_init); |