Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/open.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/string.h> |
| 8 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 10 | #include <linux/fdtable.h> |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 11 | #include <linux/fsnotify.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/tty.h> |
| 14 | #include <linux/namei.h> |
| 15 | #include <linux/backing-dev.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 16 | #include <linux/capability.h> |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 17 | #include <linux/securebits.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/security.h> |
| 19 | #include <linux/mount.h> |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 20 | #include <linux/fcntl.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 21 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <asm/uaccess.h> |
| 23 | #include <linux/fs.h> |
Yoav Zach | ef3daed | 2005-06-23 00:09:58 -0700 | [diff] [blame] | 24 | #include <linux/personality.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/pagemap.h> |
| 26 | #include <linux/syscalls.h> |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 27 | #include <linux/rcupdate.h> |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 28 | #include <linux/audit.h> |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 29 | #include <linux/falloc.h> |
Al Viro | 5ad4e53 | 2009-03-29 19:50:06 -0400 | [diff] [blame] | 30 | #include <linux/fs_struct.h> |
Al Viro | b65a9cf | 2009-12-16 06:27:40 -0500 | [diff] [blame] | 31 | #include <linux/ima.h> |
Eric Paris | 2dfc1ca | 2009-12-17 20:30:52 -0500 | [diff] [blame] | 32 | #include <linux/dnotify.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
Eric Paris | e81e3f4 | 2009-12-04 15:47:36 -0500 | [diff] [blame] | 34 | #include "internal.h" |
| 35 | |
NeilBrown | 4a30131 | 2006-01-08 01:02:39 -0800 | [diff] [blame] | 36 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
| 37 | struct file *filp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | { |
Amerigo Wang | 939a942 | 2009-08-20 19:29:03 -0700 | [diff] [blame] | 39 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | struct iattr newattrs; |
| 41 | |
| 42 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ |
| 43 | if (length < 0) |
| 44 | return -EINVAL; |
| 45 | |
| 46 | newattrs.ia_size = length; |
NeilBrown | 4a30131 | 2006-01-08 01:02:39 -0800 | [diff] [blame] | 47 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
Miklos Szeredi | cc4e69d | 2005-11-07 00:59:49 -0800 | [diff] [blame] | 48 | if (filp) { |
| 49 | newattrs.ia_file = filp; |
| 50 | newattrs.ia_valid |= ATTR_FILE; |
| 51 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
Linus Torvalds | 7b82dc0 | 2007-05-08 20:10:00 -0700 | [diff] [blame] | 53 | /* Remove suid/sgid on truncate too */ |
Amerigo Wang | 939a942 | 2009-08-20 19:29:03 -0700 | [diff] [blame] | 54 | ret = should_remove_suid(dentry); |
| 55 | if (ret) |
| 56 | newattrs.ia_valid |= ret | ATTR_FORCE; |
Linus Torvalds | 7b82dc0 | 2007-05-08 20:10:00 -0700 | [diff] [blame] | 57 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 58 | mutex_lock(&dentry->d_inode->i_mutex); |
Amerigo Wang | 939a942 | 2009-08-20 19:29:03 -0700 | [diff] [blame] | 59 | ret = notify_change(dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 60 | mutex_unlock(&dentry->d_inode->i_mutex); |
Amerigo Wang | 939a942 | 2009-08-20 19:29:03 -0700 | [diff] [blame] | 61 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | } |
| 63 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 64 | static long do_sys_truncate(const char __user *pathname, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 66 | struct path path; |
| 67 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | int error; |
| 69 | |
| 70 | error = -EINVAL; |
| 71 | if (length < 0) /* sorry, but loff_t says... */ |
| 72 | goto out; |
| 73 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 74 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | if (error) |
| 76 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 77 | inode = path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
| 79 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ |
| 80 | error = -EISDIR; |
| 81 | if (S_ISDIR(inode->i_mode)) |
| 82 | goto dput_and_out; |
| 83 | |
| 84 | error = -EINVAL; |
| 85 | if (!S_ISREG(inode->i_mode)) |
| 86 | goto dput_and_out; |
| 87 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 88 | error = mnt_want_write(path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | if (error) |
| 90 | goto dput_and_out; |
| 91 | |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 92 | error = inode_permission(inode, MAY_WRITE); |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 93 | if (error) |
| 94 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | |
| 96 | error = -EPERM; |
Miklos Szeredi | c82e42d | 2008-06-24 16:50:12 +0200 | [diff] [blame] | 97 | if (IS_APPEND(inode)) |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 98 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | error = get_write_access(inode); |
| 101 | if (error) |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 102 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 104 | /* |
| 105 | * Make sure that there are no leases. get_write_access() protects |
| 106 | * against the truncate racing with a lease-granting setlease(). |
| 107 | */ |
Al Viro | 8737c93 | 2009-12-24 06:47:55 -0500 | [diff] [blame] | 108 | error = break_lease(inode, O_WRONLY); |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 109 | if (error) |
| 110 | goto put_write_and_out; |
| 111 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | error = locks_verify_truncate(inode, NULL, length); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 113 | if (!error) |
Tetsuo Handa | ea0d3ab | 2010-06-02 13:24:43 +0900 | [diff] [blame] | 114 | error = security_path_truncate(&path); |
Christoph Hellwig | 907f455 | 2010-03-03 09:05:06 -0500 | [diff] [blame] | 115 | if (!error) |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 116 | error = do_truncate(path.dentry, length, 0, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 118 | put_write_and_out: |
| 119 | put_write_access(inode); |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 120 | mnt_drop_write_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 121 | mnt_drop_write(path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 123 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | out: |
| 125 | return error; |
| 126 | } |
| 127 | |
Heiko Carstens | 4fd8da8 | 2009-09-23 17:49:55 +0200 | [diff] [blame] | 128 | SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | { |
Heiko Carstens | 4fd8da8 | 2009-09-23 17:49:55 +0200 | [diff] [blame] | 130 | return do_sys_truncate(path, length); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | } |
| 132 | |
Matt Mackall | b01ec0e | 2006-01-08 01:05:20 -0800 | [diff] [blame] | 133 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | { |
| 135 | struct inode * inode; |
| 136 | struct dentry *dentry; |
| 137 | struct file * file; |
| 138 | int error; |
| 139 | |
| 140 | error = -EINVAL; |
| 141 | if (length < 0) |
| 142 | goto out; |
| 143 | error = -EBADF; |
| 144 | file = fget(fd); |
| 145 | if (!file) |
| 146 | goto out; |
| 147 | |
| 148 | /* explicitly opened as large or we are on 64-bit box */ |
| 149 | if (file->f_flags & O_LARGEFILE) |
| 150 | small = 0; |
| 151 | |
Josef "Jeff" Sipek | 0f7fc9e4 | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 152 | dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | inode = dentry->d_inode; |
| 154 | error = -EINVAL; |
| 155 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) |
| 156 | goto out_putf; |
| 157 | |
| 158 | error = -EINVAL; |
| 159 | /* Cannot ftruncate over 2^31 bytes without large file support */ |
| 160 | if (small && length > MAX_NON_LFS) |
| 161 | goto out_putf; |
| 162 | |
| 163 | error = -EPERM; |
| 164 | if (IS_APPEND(inode)) |
| 165 | goto out_putf; |
| 166 | |
| 167 | error = locks_verify_truncate(inode, file, length); |
| 168 | if (!error) |
Tetsuo Handa | ea0d3ab | 2010-06-02 13:24:43 +0900 | [diff] [blame] | 169 | error = security_path_truncate(&file->f_path); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 170 | if (!error) |
Peter Staubach | 6e656be | 2006-06-25 05:48:36 -0700 | [diff] [blame] | 171 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | out_putf: |
| 173 | fput(file); |
| 174 | out: |
| 175 | return error; |
| 176 | } |
| 177 | |
Heiko Carstens | bdc480e | 2009-01-14 14:14:12 +0100 | [diff] [blame] | 178 | SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | { |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 180 | long ret = do_sys_ftruncate(fd, length, 1); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 181 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 182 | asmlinkage_protect(2, ret, fd, length); |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 183 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | } |
| 185 | |
| 186 | /* LFS versions of truncate are only needed on 32 bit machines */ |
| 187 | #if BITS_PER_LONG == 32 |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 188 | SYSCALL_DEFINE(truncate64)(const char __user * path, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | { |
| 190 | return do_sys_truncate(path, length); |
| 191 | } |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 192 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 193 | asmlinkage long SyS_truncate64(long path, loff_t length) |
| 194 | { |
| 195 | return SYSC_truncate64((const char __user *) path, length); |
| 196 | } |
| 197 | SYSCALL_ALIAS(sys_truncate64, SyS_truncate64); |
| 198 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 200 | SYSCALL_DEFINE(ftruncate64)(unsigned int fd, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | { |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 202 | long ret = do_sys_ftruncate(fd, length, 0); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 203 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 204 | asmlinkage_protect(2, ret, fd, length); |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 205 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | } |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 207 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 208 | asmlinkage long SyS_ftruncate64(long fd, loff_t length) |
| 209 | { |
| 210 | return SYSC_ftruncate64((unsigned int) fd, length); |
| 211 | } |
| 212 | SYSCALL_ALIAS(sys_ftruncate64, SyS_ftruncate64); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | #endif |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 214 | #endif /* BITS_PER_LONG == 32 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 216 | |
| 217 | int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 218 | { |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 219 | struct inode *inode = file->f_path.dentry->d_inode; |
| 220 | long ret; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 221 | |
| 222 | if (offset < 0 || len <= 0) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 223 | return -EINVAL; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 224 | |
| 225 | /* Return error if mode is not supported */ |
Josef Bacik | 79124f18 | 2010-11-17 20:46:15 -0500 | [diff] [blame] | 226 | if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) |
| 227 | return -EOPNOTSUPP; |
| 228 | |
| 229 | /* Punch hole must have keep size set */ |
| 230 | if ((mode & FALLOC_FL_PUNCH_HOLE) && |
| 231 | !(mode & FALLOC_FL_KEEP_SIZE)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 232 | return -EOPNOTSUPP; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 233 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 234 | if (!(file->f_mode & FMODE_WRITE)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 235 | return -EBADF; |
Marco Stornelli | 1ca551c | 2011-03-05 11:10:19 +0100 | [diff] [blame] | 236 | |
| 237 | /* It's not possible punch hole on append only file */ |
| 238 | if (mode & FALLOC_FL_PUNCH_HOLE && IS_APPEND(inode)) |
| 239 | return -EPERM; |
| 240 | |
| 241 | if (IS_IMMUTABLE(inode)) |
| 242 | return -EPERM; |
| 243 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 244 | /* |
| 245 | * Revalidate the write permissions, in case security policy has |
| 246 | * changed since the files were opened. |
| 247 | */ |
| 248 | ret = security_file_permission(file, MAY_WRITE); |
| 249 | if (ret) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 250 | return ret; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 251 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 252 | if (S_ISFIFO(inode->i_mode)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 253 | return -ESPIPE; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 254 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 255 | /* |
| 256 | * Let individual file system decide if it supports preallocation |
| 257 | * for directories or not. |
| 258 | */ |
| 259 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 260 | return -ENODEV; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 261 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 262 | /* Check for wrap through zero too */ |
| 263 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 264 | return -EFBIG; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 265 | |
Christoph Hellwig | 2fe17c1 | 2011-01-14 13:07:43 +0100 | [diff] [blame] | 266 | if (!file->f_op->fallocate) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 267 | return -EOPNOTSUPP; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 268 | |
Christoph Hellwig | 2fe17c1 | 2011-01-14 13:07:43 +0100 | [diff] [blame] | 269 | return file->f_op->fallocate(file, mode, offset, len); |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 270 | } |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 271 | |
| 272 | SYSCALL_DEFINE(fallocate)(int fd, int mode, loff_t offset, loff_t len) |
| 273 | { |
| 274 | struct file *file; |
| 275 | int error = -EBADF; |
| 276 | |
| 277 | file = fget(fd); |
| 278 | if (file) { |
| 279 | error = do_fallocate(file, mode, offset, len); |
| 280 | fput(file); |
| 281 | } |
| 282 | |
| 283 | return error; |
| 284 | } |
| 285 | |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 286 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 287 | asmlinkage long SyS_fallocate(long fd, long mode, loff_t offset, loff_t len) |
| 288 | { |
| 289 | return SYSC_fallocate((int)fd, (int)mode, offset, len); |
| 290 | } |
| 291 | SYSCALL_ALIAS(sys_fallocate, SyS_fallocate); |
| 292 | #endif |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 293 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | /* |
| 295 | * access() needs to use the real uid/gid, not the effective uid/gid. |
| 296 | * We do this by temporarily clearing all FS-related capabilities and |
| 297 | * switching the fsuid/fsgid around to the real ones. |
| 298 | */ |
Heiko Carstens | 6559eed8 | 2009-01-14 14:14:32 +0100 | [diff] [blame] | 299 | SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 301 | const struct cred *old_cred; |
| 302 | struct cred *override_cred; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 303 | struct path path; |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 304 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | int res; |
| 306 | |
| 307 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ |
| 308 | return -EINVAL; |
| 309 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 310 | override_cred = prepare_creds(); |
| 311 | if (!override_cred) |
| 312 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 314 | override_cred->fsuid = override_cred->uid; |
| 315 | override_cred->fsgid = override_cred->gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 317 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
David Howells | 1cdcbec | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 318 | /* Clear the capabilities if we switch to a non-root user */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 319 | if (override_cred->uid) |
| 320 | cap_clear(override_cred->cap_effective); |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 321 | else |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 322 | override_cred->cap_effective = |
| 323 | override_cred->cap_permitted; |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 324 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 326 | old_cred = override_creds(override_cred); |
| 327 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 328 | res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 329 | if (res) |
| 330 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 332 | inode = path.dentry->d_inode; |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 333 | |
| 334 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { |
Al Viro | 3052447 | 2008-07-22 00:02:33 -0400 | [diff] [blame] | 335 | /* |
| 336 | * MAY_EXEC on regular files is denied if the fs is mounted |
| 337 | * with the "noexec" flag. |
| 338 | */ |
| 339 | res = -EACCES; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 340 | if (path.mnt->mnt_flags & MNT_NOEXEC) |
Al Viro | 3052447 | 2008-07-22 00:02:33 -0400 | [diff] [blame] | 341 | goto out_path_release; |
| 342 | } |
| 343 | |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 344 | res = inode_permission(inode, mode | MAY_ACCESS); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 345 | /* SuS v2 requires we report a read only fs too */ |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 346 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 347 | goto out_path_release; |
Dave Hansen | 2f676cb | 2008-02-15 14:37:55 -0800 | [diff] [blame] | 348 | /* |
| 349 | * This is a rare case where using __mnt_is_readonly() |
| 350 | * is OK without a mnt_want/drop_write() pair. Since |
| 351 | * no actual write to the fs is performed here, we do |
| 352 | * not need to telegraph to that to anyone. |
| 353 | * |
| 354 | * By doing this, we accept that this access is |
| 355 | * inherently racy and know that the fs may change |
| 356 | * state before we even see this result. |
| 357 | */ |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 358 | if (__mnt_is_readonly(path.mnt)) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 359 | res = -EROFS; |
| 360 | |
| 361 | out_path_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 362 | path_put(&path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 363 | out: |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 364 | revert_creds(old_cred); |
| 365 | put_cred(override_cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | return res; |
| 367 | } |
| 368 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 369 | SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 370 | { |
| 371 | return sys_faccessat(AT_FDCWD, filename, mode); |
| 372 | } |
| 373 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 374 | SYSCALL_DEFINE1(chdir, const char __user *, filename) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 376 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | int error; |
| 378 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 379 | error = user_path_dir(filename, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | if (error) |
| 381 | goto out; |
| 382 | |
Eric Paris | 9cfcac8 | 2010-07-23 11:43:51 -0400 | [diff] [blame] | 383 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | if (error) |
| 385 | goto dput_and_out; |
| 386 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 387 | set_fs_pwd(current->fs, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | |
| 389 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 390 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | out: |
| 392 | return error; |
| 393 | } |
| 394 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 395 | SYSCALL_DEFINE1(fchdir, unsigned int, fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | { |
| 397 | struct file *file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | int error; |
| 400 | |
| 401 | error = -EBADF; |
| 402 | file = fget(fd); |
| 403 | if (!file) |
| 404 | goto out; |
| 405 | |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 406 | inode = file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | |
| 408 | error = -ENOTDIR; |
| 409 | if (!S_ISDIR(inode->i_mode)) |
| 410 | goto out_putf; |
| 411 | |
Eric Paris | 9cfcac8 | 2010-07-23 11:43:51 -0400 | [diff] [blame] | 412 | error = inode_permission(inode, MAY_EXEC | MAY_CHDIR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | if (!error) |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 414 | set_fs_pwd(current->fs, &file->f_path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | out_putf: |
| 416 | fput(file); |
| 417 | out: |
| 418 | return error; |
| 419 | } |
| 420 | |
Heiko Carstens | 3480b25 | 2009-01-14 14:14:16 +0100 | [diff] [blame] | 421 | SYSCALL_DEFINE1(chroot, const char __user *, filename) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 423 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | int error; |
| 425 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 426 | error = user_path_dir(filename, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | if (error) |
| 428 | goto out; |
| 429 | |
Eric Paris | 9cfcac8 | 2010-07-23 11:43:51 -0400 | [diff] [blame] | 430 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | if (error) |
| 432 | goto dput_and_out; |
| 433 | |
| 434 | error = -EPERM; |
| 435 | if (!capable(CAP_SYS_CHROOT)) |
| 436 | goto dput_and_out; |
Tetsuo Handa | 8b8efb4 | 2009-10-04 21:49:48 +0900 | [diff] [blame] | 437 | error = security_path_chroot(&path); |
| 438 | if (error) |
| 439 | goto dput_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 441 | set_fs_root(current->fs, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | error = 0; |
| 443 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 444 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | out: |
| 446 | return error; |
| 447 | } |
| 448 | |
Al Viro | e57712e | 2011-07-26 04:15:54 -0400 | [diff] [blame] | 449 | static int chmod_common(struct path *path, umode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | { |
Al Viro | e57712e | 2011-07-26 04:15:54 -0400 | [diff] [blame] | 451 | struct inode *inode = path->dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | struct iattr newattrs; |
Al Viro | e57712e | 2011-07-26 04:15:54 -0400 | [diff] [blame] | 453 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | |
Al Viro | e57712e | 2011-07-26 04:15:54 -0400 | [diff] [blame] | 455 | error = mnt_want_write(path->mnt); |
| 456 | if (error) |
| 457 | return error; |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 458 | mutex_lock(&inode->i_mutex); |
Al Viro | e57712e | 2011-07-26 04:15:54 -0400 | [diff] [blame] | 459 | error = security_path_chmod(path->dentry, path->mnt, mode); |
| 460 | if (error) |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 461 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 463 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
Al Viro | e57712e | 2011-07-26 04:15:54 -0400 | [diff] [blame] | 464 | error = notify_change(path->dentry, &newattrs); |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 465 | out_unlock: |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 466 | mutex_unlock(&inode->i_mutex); |
Al Viro | e57712e | 2011-07-26 04:15:54 -0400 | [diff] [blame] | 467 | mnt_drop_write(path->mnt); |
| 468 | return error; |
| 469 | } |
| 470 | |
| 471 | SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode) |
| 472 | { |
| 473 | struct file * file; |
| 474 | int err = -EBADF; |
| 475 | |
| 476 | file = fget(fd); |
| 477 | if (file) { |
| 478 | audit_inode(NULL, file->f_path.dentry); |
| 479 | err = chmod_common(&file->f_path, mode); |
| 480 | fput(file); |
| 481 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | return err; |
| 483 | } |
| 484 | |
Heiko Carstens | 6559eed8 | 2009-01-14 14:14:32 +0100 | [diff] [blame] | 485 | SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, mode_t, mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 487 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 490 | error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
Al Viro | e57712e | 2011-07-26 04:15:54 -0400 | [diff] [blame] | 491 | if (!error) { |
| 492 | error = chmod_common(&path, mode); |
| 493 | path_put(&path); |
| 494 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | return error; |
| 496 | } |
| 497 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 498 | SYSCALL_DEFINE2(chmod, const char __user *, filename, mode_t, mode) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 499 | { |
| 500 | return sys_fchmodat(AT_FDCWD, filename, mode); |
| 501 | } |
| 502 | |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 503 | static int chown_common(struct path *path, uid_t user, gid_t group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | { |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 505 | struct inode *inode = path->dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | int error; |
| 507 | struct iattr newattrs; |
| 508 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | newattrs.ia_valid = ATTR_CTIME; |
| 510 | if (user != (uid_t) -1) { |
| 511 | newattrs.ia_valid |= ATTR_UID; |
| 512 | newattrs.ia_uid = user; |
| 513 | } |
| 514 | if (group != (gid_t) -1) { |
| 515 | newattrs.ia_valid |= ATTR_GID; |
| 516 | newattrs.ia_gid = group; |
| 517 | } |
| 518 | if (!S_ISDIR(inode->i_mode)) |
Serge E. Hallyn | b537677 | 2007-10-16 23:31:36 -0700 | [diff] [blame] | 519 | newattrs.ia_valid |= |
| 520 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 521 | mutex_lock(&inode->i_mutex); |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 522 | error = security_path_chown(path, user, group); |
| 523 | if (!error) |
| 524 | error = notify_change(path->dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 525 | mutex_unlock(&inode->i_mutex); |
Miklos Szeredi | beb29e0 | 2008-07-01 15:01:29 +0200 | [diff] [blame] | 526 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | return error; |
| 528 | } |
| 529 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 530 | SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 532 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | int error; |
| 534 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 535 | error = user_path(filename, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 536 | if (error) |
| 537 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 538 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 539 | if (error) |
| 540 | goto out_release; |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 541 | error = chown_common(&path, user, group); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 542 | mnt_drop_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 543 | out_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 544 | path_put(&path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 545 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | return error; |
| 547 | } |
| 548 | |
Heiko Carstens | 6559eed8 | 2009-01-14 14:14:32 +0100 | [diff] [blame] | 549 | SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, |
| 550 | gid_t, group, int, flag) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 551 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 552 | struct path path; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 553 | int error = -EINVAL; |
Al Viro | 65cfc67 | 2011-03-13 15:56:26 -0400 | [diff] [blame] | 554 | int lookup_flags; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 555 | |
Al Viro | 65cfc67 | 2011-03-13 15:56:26 -0400 | [diff] [blame] | 556 | if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 557 | goto out; |
| 558 | |
Al Viro | 65cfc67 | 2011-03-13 15:56:26 -0400 | [diff] [blame] | 559 | lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
| 560 | if (flag & AT_EMPTY_PATH) |
| 561 | lookup_flags |= LOOKUP_EMPTY; |
| 562 | error = user_path_at(dfd, filename, lookup_flags, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 563 | if (error) |
| 564 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 565 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 566 | if (error) |
| 567 | goto out_release; |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 568 | error = chown_common(&path, user, group); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 569 | mnt_drop_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 570 | out_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 571 | path_put(&path); |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 572 | out: |
| 573 | return error; |
| 574 | } |
| 575 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 576 | SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 578 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | int error; |
| 580 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 581 | error = user_lpath(filename, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 582 | if (error) |
| 583 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 584 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 585 | if (error) |
| 586 | goto out_release; |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 587 | error = chown_common(&path, user, group); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 588 | mnt_drop_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 589 | out_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 590 | path_put(&path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 591 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | return error; |
| 593 | } |
| 594 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 595 | SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | { |
| 597 | struct file * file; |
| 598 | int error = -EBADF; |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 599 | struct dentry * dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | |
| 601 | file = fget(fd); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 602 | if (!file) |
| 603 | goto out; |
| 604 | |
npiggin@suse.de | 96029c4 | 2009-04-26 20:25:55 +1000 | [diff] [blame] | 605 | error = mnt_want_write_file(file); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 606 | if (error) |
| 607 | goto out_fput; |
Josef "Jeff" Sipek | 0f7fc9e4 | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 608 | dentry = file->f_path.dentry; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 609 | audit_inode(NULL, dentry); |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 610 | error = chown_common(&file->f_path, user, group); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 611 | mnt_drop_write(file->f_path.mnt); |
| 612 | out_fput: |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 613 | fput(file); |
| 614 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | return error; |
| 616 | } |
| 617 | |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 618 | /* |
| 619 | * You have to be very careful that these write |
| 620 | * counts get cleaned up in error cases and |
| 621 | * upon __fput(). This should probably never |
| 622 | * be called outside of __dentry_open(). |
| 623 | */ |
| 624 | static inline int __get_file_write_access(struct inode *inode, |
| 625 | struct vfsmount *mnt) |
| 626 | { |
| 627 | int error; |
| 628 | error = get_write_access(inode); |
| 629 | if (error) |
| 630 | return error; |
| 631 | /* |
| 632 | * Do not take mount writer counts on |
| 633 | * special files since no writes to |
| 634 | * the mount itself will occur. |
| 635 | */ |
| 636 | if (!special_file(inode->i_mode)) { |
| 637 | /* |
| 638 | * Balanced in __fput() |
| 639 | */ |
| 640 | error = mnt_want_write(mnt); |
| 641 | if (error) |
| 642 | put_write_access(inode); |
| 643 | } |
| 644 | return error; |
| 645 | } |
| 646 | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 647 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
Al Viro | 482928d | 2009-12-19 10:10:39 -0500 | [diff] [blame] | 648 | struct file *f, |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 649 | int (*open)(struct inode *, struct file *), |
| 650 | const struct cred *cred) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | { |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame] | 652 | static const struct file_operations empty_fops = {}; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | struct inode *inode; |
| 654 | int error; |
| 655 | |
Al Viro | 5300990 | 2009-12-19 10:15:07 -0500 | [diff] [blame] | 656 | f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 657 | FMODE_PREAD | FMODE_PWRITE; |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame] | 658 | |
| 659 | if (unlikely(f->f_flags & O_PATH)) |
| 660 | f->f_mode = FMODE_PATH; |
| 661 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | inode = dentry->d_inode; |
| 663 | if (f->f_mode & FMODE_WRITE) { |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 664 | error = __get_file_write_access(inode, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | if (error) |
| 666 | goto cleanup_file; |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 667 | if (!special_file(inode->i_mode)) |
| 668 | file_take_write(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | } |
| 670 | |
| 671 | f->f_mapping = inode->i_mapping; |
Josef "Jeff" Sipek | 0f7fc9e4 | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 672 | f->f_path.dentry = dentry; |
| 673 | f->f_path.mnt = mnt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | f->f_pos = 0; |
Nick Piggin | ee2ffa0 | 2010-08-18 04:37:35 +1000 | [diff] [blame] | 675 | file_sb_list_add(f, inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 676 | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame] | 677 | if (unlikely(f->f_mode & FMODE_PATH)) { |
| 678 | f->f_op = &empty_fops; |
| 679 | return f; |
| 680 | } |
| 681 | |
| 682 | f->f_op = fops_get(inode->i_fop); |
| 683 | |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 684 | error = security_dentry_open(f, cred); |
Yuichi Nakamura | 788e7dd | 2007-09-14 09:27:07 +0900 | [diff] [blame] | 685 | if (error) |
| 686 | goto cleanup_all; |
| 687 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 688 | if (!open && f->f_op) |
| 689 | open = f->f_op->open; |
| 690 | if (open) { |
| 691 | error = open(inode, f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | if (error) |
| 693 | goto cleanup_all; |
| 694 | } |
Mimi Zohar | 890275b5 | 2010-11-02 10:13:07 -0400 | [diff] [blame] | 695 | if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) |
| 696 | i_readcount_inc(inode); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 697 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
| 699 | |
| 700 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); |
| 701 | |
| 702 | /* NB: we're sure to have correct a_ops only after f_op->open */ |
| 703 | if (f->f_flags & O_DIRECT) { |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 704 | if (!f->f_mapping->a_ops || |
| 705 | ((!f->f_mapping->a_ops->direct_IO) && |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 706 | (!f->f_mapping->a_ops->get_xip_mem))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 707 | fput(f); |
| 708 | f = ERR_PTR(-EINVAL); |
| 709 | } |
| 710 | } |
| 711 | |
| 712 | return f; |
| 713 | |
| 714 | cleanup_all: |
| 715 | fops_put(f->f_op); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 716 | if (f->f_mode & FMODE_WRITE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | put_write_access(inode); |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 718 | if (!special_file(inode->i_mode)) { |
| 719 | /* |
| 720 | * We don't consider this a real |
| 721 | * mnt_want/drop_write() pair |
| 722 | * because it all happenend right |
| 723 | * here, so just reset the state. |
| 724 | */ |
| 725 | file_reset_write(f); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 726 | mnt_drop_write(mnt); |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 727 | } |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 728 | } |
Nick Piggin | ee2ffa0 | 2010-08-18 04:37:35 +1000 | [diff] [blame] | 729 | file_sb_list_del(f); |
Josef "Jeff" Sipek | 0f7fc9e4 | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 730 | f->f_path.dentry = NULL; |
| 731 | f->f_path.mnt = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | cleanup_file: |
| 733 | put_filp(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | dput(dentry); |
| 735 | mntput(mnt); |
| 736 | return ERR_PTR(error); |
| 737 | } |
| 738 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 739 | /** |
| 740 | * lookup_instantiate_filp - instantiates the open intent filp |
| 741 | * @nd: pointer to nameidata |
| 742 | * @dentry: pointer to dentry |
| 743 | * @open: open callback |
| 744 | * |
| 745 | * Helper for filesystems that want to use lookup open intents and pass back |
| 746 | * a fully instantiated struct file to the caller. |
| 747 | * This function is meant to be called from within a filesystem's |
| 748 | * lookup method. |
Oleg Drokin | 9a56c21 | 2006-03-25 03:07:02 -0800 | [diff] [blame] | 749 | * Beware of calling it for non-regular files! Those ->open methods might block |
| 750 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, |
| 751 | * leading to a deadlock, as nobody can open that fifo anymore, because |
| 752 | * another process to open fifo will block on locked parent when doing lookup). |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 753 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
| 754 | * path information remains valid. |
| 755 | * If the open callback is set to NULL, then the standard f_op->open() |
| 756 | * filesystem callback is substituted. |
| 757 | */ |
| 758 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, |
| 759 | int (*open)(struct inode *, struct file *)) |
| 760 | { |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 761 | const struct cred *cred = current_cred(); |
| 762 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 763 | if (IS_ERR(nd->intent.open.file)) |
| 764 | goto out; |
| 765 | if (IS_ERR(dentry)) |
| 766 | goto out_err; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 767 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 768 | nd->intent.open.file, |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 769 | open, cred); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 770 | out: |
| 771 | return nd->intent.open.file; |
| 772 | out_err: |
| 773 | release_open_intent(nd); |
Konstantin Khlebnikov | 5a9a436 | 2011-07-17 15:35:12 +0400 | [diff] [blame] | 774 | nd->intent.open.file = ERR_CAST(dentry); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 775 | goto out; |
| 776 | } |
| 777 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); |
| 778 | |
| 779 | /** |
| 780 | * nameidata_to_filp - convert a nameidata to an open filp. |
| 781 | * @nd: pointer to nameidata |
| 782 | * @flags: open flags |
| 783 | * |
| 784 | * Note that this function destroys the original nameidata |
| 785 | */ |
Al Viro | 482928d | 2009-12-19 10:10:39 -0500 | [diff] [blame] | 786 | struct file *nameidata_to_filp(struct nameidata *nd) |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 787 | { |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 788 | const struct cred *cred = current_cred(); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 789 | struct file *filp; |
| 790 | |
| 791 | /* Pick up the filp from the open intent */ |
| 792 | filp = nd->intent.open.file; |
Linus Torvalds | 2dab597 | 2011-02-11 15:53:38 -0800 | [diff] [blame] | 793 | nd->intent.open.file = NULL; |
| 794 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 795 | /* Has the filesystem initialised the file for us? */ |
Al Viro | d893f1b | 2010-10-29 03:30:42 -0400 | [diff] [blame] | 796 | if (filp->f_path.dentry == NULL) { |
| 797 | path_get(&nd->path); |
Al Viro | 482928d | 2009-12-19 10:10:39 -0500 | [diff] [blame] | 798 | filp = __dentry_open(nd->path.dentry, nd->path.mnt, filp, |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 799 | NULL, cred); |
Al Viro | d893f1b | 2010-10-29 03:30:42 -0400 | [diff] [blame] | 800 | } |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 801 | return filp; |
| 802 | } |
| 803 | |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 804 | /* |
| 805 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an |
| 806 | * error. |
| 807 | */ |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 808 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, |
| 809 | const struct cred *cred) |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 810 | { |
| 811 | int error; |
| 812 | struct file *f; |
| 813 | |
David Howells | e0e8173 | 2009-09-02 09:13:40 +0100 | [diff] [blame] | 814 | validate_creds(cred); |
| 815 | |
Tetsuo Handa | c212f9a | 2011-01-19 21:08:41 +0900 | [diff] [blame] | 816 | /* We must always pass in a valid mount pointer. */ |
| 817 | BUG_ON(!mnt); |
Christoph Hellwig | 322ee5b | 2008-02-15 14:37:24 -0800 | [diff] [blame] | 818 | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 819 | error = -ENFILE; |
| 820 | f = get_empty_filp(); |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 821 | if (f == NULL) { |
| 822 | dput(dentry); |
| 823 | mntput(mnt); |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 824 | return ERR_PTR(error); |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 825 | } |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 826 | |
Al Viro | 482928d | 2009-12-19 10:10:39 -0500 | [diff] [blame] | 827 | f->f_flags = flags; |
| 828 | return __dentry_open(dentry, mnt, f, NULL, cred); |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 829 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | EXPORT_SYMBOL(dentry_open); |
| 831 | |
Matt Mackall | b01ec0e | 2006-01-08 01:05:20 -0800 | [diff] [blame] | 832 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | { |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 834 | struct fdtable *fdt = files_fdtable(files); |
| 835 | __FD_CLR(fd, fdt->open_fds); |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 836 | if (fd < files->next_fd) |
| 837 | files->next_fd = fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | } |
| 839 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 840 | void put_unused_fd(unsigned int fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | { |
| 842 | struct files_struct *files = current->files; |
| 843 | spin_lock(&files->file_lock); |
| 844 | __put_unused_fd(files, fd); |
| 845 | spin_unlock(&files->file_lock); |
| 846 | } |
| 847 | |
| 848 | EXPORT_SYMBOL(put_unused_fd); |
| 849 | |
| 850 | /* |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 851 | * Install a file pointer in the fd array. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | * |
| 853 | * The VFS is full of places where we drop the files lock between |
| 854 | * setting the open_fds bitmap and installing the file in the file |
| 855 | * array. At any such point, we are vulnerable to a dup2() race |
| 856 | * installing a file in the array before us. We need to detect this and |
| 857 | * fput() the struct file we are about to overwrite in this case. |
| 858 | * |
| 859 | * It should never happen - if we allow dup2() do it, _really_ bad things |
| 860 | * will follow. |
| 861 | */ |
| 862 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 863 | void fd_install(unsigned int fd, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 864 | { |
| 865 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 866 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 867 | spin_lock(&files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 868 | fdt = files_fdtable(files); |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 869 | BUG_ON(fdt->fd[fd] != NULL); |
| 870 | rcu_assign_pointer(fdt->fd[fd], file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | spin_unlock(&files->file_lock); |
| 872 | } |
| 873 | |
| 874 | EXPORT_SYMBOL(fd_install); |
| 875 | |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 876 | static inline int build_open_flags(int flags, int mode, struct open_flags *op) |
| 877 | { |
| 878 | int lookup_flags = 0; |
| 879 | int acc_mode; |
| 880 | |
| 881 | if (!(flags & O_CREAT)) |
| 882 | mode = 0; |
| 883 | op->mode = mode; |
| 884 | |
| 885 | /* Must never be set by userspace */ |
| 886 | flags &= ~FMODE_NONOTIFY; |
| 887 | |
| 888 | /* |
| 889 | * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only |
| 890 | * check for O_DSYNC if the need any syncing at all we enforce it's |
| 891 | * always set instead of having to deal with possibly weird behaviour |
| 892 | * for malicious applications setting only __O_SYNC. |
| 893 | */ |
| 894 | if (flags & __O_SYNC) |
| 895 | flags |= O_DSYNC; |
| 896 | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame] | 897 | /* |
| 898 | * If we have O_PATH in the open flag. Then we |
| 899 | * cannot have anything other than the below set of flags |
| 900 | */ |
| 901 | if (flags & O_PATH) { |
| 902 | flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH; |
| 903 | acc_mode = 0; |
| 904 | } else { |
| 905 | acc_mode = MAY_OPEN | ACC_MODE(flags); |
| 906 | } |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 907 | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame] | 908 | op->open_flag = flags; |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 909 | |
| 910 | /* O_TRUNC implies we need access checks for write permissions */ |
| 911 | if (flags & O_TRUNC) |
| 912 | acc_mode |= MAY_WRITE; |
| 913 | |
| 914 | /* Allow the LSM permission hook to distinguish append |
| 915 | access from general write access. */ |
| 916 | if (flags & O_APPEND) |
| 917 | acc_mode |= MAY_APPEND; |
| 918 | |
| 919 | op->acc_mode = acc_mode; |
| 920 | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame] | 921 | op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN; |
| 922 | |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 923 | if (flags & O_CREAT) { |
| 924 | op->intent |= LOOKUP_CREATE; |
| 925 | if (flags & O_EXCL) |
| 926 | op->intent |= LOOKUP_EXCL; |
| 927 | } |
| 928 | |
| 929 | if (flags & O_DIRECTORY) |
| 930 | lookup_flags |= LOOKUP_DIRECTORY; |
| 931 | if (!(flags & O_NOFOLLOW)) |
| 932 | lookup_flags |= LOOKUP_FOLLOW; |
| 933 | return lookup_flags; |
| 934 | } |
| 935 | |
| 936 | /** |
| 937 | * filp_open - open file and return file pointer |
| 938 | * |
| 939 | * @filename: path to open |
| 940 | * @flags: open flags as per the open(2) second argument |
| 941 | * @mode: mode for the new file if O_CREAT is set, else ignored |
| 942 | * |
| 943 | * This is the helper to open a file from kernelspace if you really |
| 944 | * have to. But in generally you should not do this, so please move |
| 945 | * along, nothing to see here.. |
| 946 | */ |
| 947 | struct file *filp_open(const char *filename, int flags, int mode) |
| 948 | { |
| 949 | struct open_flags op; |
| 950 | int lookup = build_open_flags(flags, mode, &op); |
| 951 | return do_filp_open(AT_FDCWD, filename, &op, lookup); |
| 952 | } |
| 953 | EXPORT_SYMBOL(filp_open); |
| 954 | |
Al Viro | 73d049a | 2011-03-11 12:08:24 -0500 | [diff] [blame] | 955 | struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, |
| 956 | const char *filename, int flags) |
| 957 | { |
| 958 | struct open_flags op; |
| 959 | int lookup = build_open_flags(flags, 0, &op); |
| 960 | if (flags & O_CREAT) |
| 961 | return ERR_PTR(-EINVAL); |
| 962 | if (!filename && (flags & O_DIRECTORY)) |
| 963 | if (!dentry->d_inode->i_op->lookup) |
| 964 | return ERR_PTR(-ENOTDIR); |
| 965 | return do_file_open_root(dentry, mnt, filename, &op, lookup); |
| 966 | } |
| 967 | EXPORT_SYMBOL(file_open_root); |
| 968 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 969 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 970 | { |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 971 | struct open_flags op; |
| 972 | int lookup = build_open_flags(flags, mode, &op); |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 973 | char *tmp = getname(filename); |
| 974 | int fd = PTR_ERR(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 975 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | if (!IS_ERR(tmp)) { |
Ulrich Drepper | f23513e | 2007-07-15 23:40:32 -0700 | [diff] [blame] | 977 | fd = get_unused_fd_flags(flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | if (fd >= 0) { |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 979 | struct file *f = do_filp_open(dfd, tmp, &op, lookup); |
Telemaque Ndizihiwe | fed2fc1 | 2005-06-23 00:10:33 -0700 | [diff] [blame] | 980 | if (IS_ERR(f)) { |
| 981 | put_unused_fd(fd); |
| 982 | fd = PTR_ERR(f); |
| 983 | } else { |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 984 | fsnotify_open(f); |
Telemaque Ndizihiwe | fed2fc1 | 2005-06-23 00:10:33 -0700 | [diff] [blame] | 985 | fd_install(fd, f); |
| 986 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 987 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 988 | putname(tmp); |
| 989 | } |
| 990 | return fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | } |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 992 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 993 | SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, int, mode) |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 994 | { |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 995 | long ret; |
| 996 | |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 997 | if (force_o_largefile()) |
| 998 | flags |= O_LARGEFILE; |
| 999 | |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1000 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
| 1001 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 1002 | asmlinkage_protect(3, ret, filename, flags, mode); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1003 | return ret; |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 1004 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | |
Heiko Carstens | 6559eed8 | 2009-01-14 14:14:32 +0100 | [diff] [blame] | 1006 | SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, |
| 1007 | int, mode) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1008 | { |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1009 | long ret; |
| 1010 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1011 | if (force_o_largefile()) |
| 1012 | flags |= O_LARGEFILE; |
| 1013 | |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1014 | ret = do_sys_open(dfd, filename, flags, mode); |
| 1015 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 1016 | asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1017 | return ret; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1018 | } |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1019 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1020 | #ifndef __alpha__ |
| 1021 | |
| 1022 | /* |
| 1023 | * For backward compatibility? Maybe this should be moved |
| 1024 | * into arch/i386 instead? |
| 1025 | */ |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 1026 | SYSCALL_DEFINE2(creat, const char __user *, pathname, int, mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1027 | { |
| 1028 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); |
| 1029 | } |
| 1030 | |
| 1031 | #endif |
| 1032 | |
| 1033 | /* |
| 1034 | * "id" is the POSIX thread ID. We use the |
| 1035 | * files pointer for this.. |
| 1036 | */ |
| 1037 | int filp_close(struct file *filp, fl_owner_t id) |
| 1038 | { |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 1039 | int retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1040 | |
| 1041 | if (!file_count(filp)) { |
| 1042 | printk(KERN_ERR "VFS: Close: file count is 0\n"); |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 1043 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1044 | } |
| 1045 | |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 1046 | if (filp->f_op && filp->f_op->flush) |
Miklos Szeredi | 75e1fcc | 2006-06-23 02:05:12 -0700 | [diff] [blame] | 1047 | retval = filp->f_op->flush(filp, id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1048 | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame] | 1049 | if (likely(!(filp->f_mode & FMODE_PATH))) { |
| 1050 | dnotify_flush(filp, id); |
| 1051 | locks_remove_posix(filp, id); |
| 1052 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1053 | fput(filp); |
| 1054 | return retval; |
| 1055 | } |
| 1056 | |
| 1057 | EXPORT_SYMBOL(filp_close); |
| 1058 | |
| 1059 | /* |
| 1060 | * Careful here! We test whether the file pointer is NULL before |
| 1061 | * releasing the fd. This ensures that one clone task can't release |
| 1062 | * an fd while another clone is opening it. |
| 1063 | */ |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 1064 | SYSCALL_DEFINE1(close, unsigned int, fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | { |
| 1066 | struct file * filp; |
| 1067 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1068 | struct fdtable *fdt; |
Ernie Petrides | ee731f4 | 2006-09-29 02:00:13 -0700 | [diff] [blame] | 1069 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1070 | |
| 1071 | spin_lock(&files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1072 | fdt = files_fdtable(files); |
| 1073 | if (fd >= fdt->max_fds) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | goto out_unlock; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1075 | filp = fdt->fd[fd]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | if (!filp) |
| 1077 | goto out_unlock; |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 1078 | rcu_assign_pointer(fdt->fd[fd], NULL); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1079 | FD_CLR(fd, fdt->close_on_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1080 | __put_unused_fd(files, fd); |
| 1081 | spin_unlock(&files->file_lock); |
Ernie Petrides | ee731f4 | 2006-09-29 02:00:13 -0700 | [diff] [blame] | 1082 | retval = filp_close(filp, files); |
| 1083 | |
| 1084 | /* can't restart close syscall because file table entry was cleared */ |
| 1085 | if (unlikely(retval == -ERESTARTSYS || |
| 1086 | retval == -ERESTARTNOINTR || |
| 1087 | retval == -ERESTARTNOHAND || |
| 1088 | retval == -ERESTART_RESTARTBLOCK)) |
| 1089 | retval = -EINTR; |
| 1090 | |
| 1091 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1092 | |
| 1093 | out_unlock: |
| 1094 | spin_unlock(&files->file_lock); |
| 1095 | return -EBADF; |
| 1096 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1097 | EXPORT_SYMBOL(sys_close); |
| 1098 | |
| 1099 | /* |
| 1100 | * This routine simulates a hangup on the tty, to arrange that users |
| 1101 | * are given clean terminals at login time. |
| 1102 | */ |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 1103 | SYSCALL_DEFINE0(vhangup) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1104 | { |
| 1105 | if (capable(CAP_SYS_TTY_CONFIG)) { |
Alan Cox | 2cb5998 | 2008-10-13 10:40:30 +0100 | [diff] [blame] | 1106 | tty_vhangup_self(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1107 | return 0; |
| 1108 | } |
| 1109 | return -EPERM; |
| 1110 | } |
| 1111 | |
| 1112 | /* |
| 1113 | * Called when an inode is about to be open. |
| 1114 | * We use this to disallow opening large files on 32bit systems if |
| 1115 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force |
| 1116 | * on this flag in sys_open. |
| 1117 | */ |
| 1118 | int generic_file_open(struct inode * inode, struct file * filp) |
| 1119 | { |
| 1120 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) |
Alan Cox | a9c62a1 | 2007-10-16 23:30:22 -0700 | [diff] [blame] | 1121 | return -EOVERFLOW; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1122 | return 0; |
| 1123 | } |
| 1124 | |
| 1125 | EXPORT_SYMBOL(generic_file_open); |
| 1126 | |
| 1127 | /* |
| 1128 | * This is used by subsystems that don't want seekable |
Dmitry Torokhov | 06b1e10 | 2010-08-10 18:01:33 -0700 | [diff] [blame] | 1129 | * file descriptors. The function is not supposed to ever fail, the only |
| 1130 | * reason it returns an 'int' and not 'void' is so that it can be plugged |
| 1131 | * directly into file_operations structure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1132 | */ |
| 1133 | int nonseekable_open(struct inode *inode, struct file *filp) |
| 1134 | { |
| 1135 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); |
| 1136 | return 0; |
| 1137 | } |
| 1138 | |
| 1139 | EXPORT_SYMBOL(nonseekable_open); |