| /* |
| * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. |
| * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
| * |
| * This copyrighted material is made available to anyone wishing to use, |
| * modify, copy, or redistribute it subject to the terms and conditions |
| * of the GNU General Public License version 2. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/buffer_head.h> |
| #include <linux/delay.h> |
| #include <linux/sort.h> |
| #include <linux/jhash.h> |
| #include <linux/kallsyms.h> |
| #include <linux/gfs2_ondisk.h> |
| #include <linux/list.h> |
| #include <linux/wait.h> |
| #include <linux/module.h> |
| #include <asm/uaccess.h> |
| #include <linux/seq_file.h> |
| #include <linux/debugfs.h> |
| #include <linux/kthread.h> |
| #include <linux/freezer.h> |
| #include <linux/workqueue.h> |
| #include <linux/jiffies.h> |
| #include <linux/rcupdate.h> |
| #include <linux/rculist_bl.h> |
| #include <linux/bit_spinlock.h> |
| #include <linux/percpu.h> |
| #include <linux/list_sort.h> |
| |
| #include "gfs2.h" |
| #include "incore.h" |
| #include "glock.h" |
| #include "glops.h" |
| #include "inode.h" |
| #include "lops.h" |
| #include "meta_io.h" |
| #include "quota.h" |
| #include "super.h" |
| #include "util.h" |
| #include "bmap.h" |
| #define CREATE_TRACE_POINTS |
| #include "trace_gfs2.h" |
| |
| struct gfs2_glock_iter { |
| int hash; /* hash bucket index */ |
| unsigned nhash; /* Index within current bucket */ |
| struct gfs2_sbd *sdp; /* incore superblock */ |
| struct gfs2_glock *gl; /* current glock struct */ |
| loff_t last_pos; /* last position */ |
| }; |
| |
| typedef void (*glock_examiner) (struct gfs2_glock * gl); |
| |
| static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); |
| |
| static struct dentry *gfs2_root; |
| static struct workqueue_struct *glock_workqueue; |
| struct workqueue_struct *gfs2_delete_workqueue; |
| static LIST_HEAD(lru_list); |
| static atomic_t lru_count = ATOMIC_INIT(0); |
| static DEFINE_SPINLOCK(lru_lock); |
| |
| #define GFS2_GL_HASH_SHIFT 15 |
| #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
| #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) |
| |
| static struct hlist_bl_head gl_hash_table[GFS2_GL_HASH_SIZE]; |
| static struct dentry *gfs2_root; |
| |
| /** |
| * gl_hash() - Turn glock number into hash bucket number |
| * @lock: The glock number |
| * |
| * Returns: The number of the corresponding hash bucket |
| */ |
| |
| static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
| const struct lm_lockname *name) |
| { |
| unsigned int h; |
| |
| h = jhash(&name->ln_number, sizeof(u64), 0); |
| h = jhash(&name->ln_type, sizeof(unsigned int), h); |
| h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
| h &= GFS2_GL_HASH_MASK; |
| |
| return h; |
| } |
| |
| static inline void spin_lock_bucket(unsigned int hash) |
| { |
| hlist_bl_lock(&gl_hash_table[hash]); |
| } |
| |
| static inline void spin_unlock_bucket(unsigned int hash) |
| { |
| hlist_bl_unlock(&gl_hash_table[hash]); |
| } |
| |
| static void gfs2_glock_dealloc(struct rcu_head *rcu) |
| { |
| struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu); |
| |
| if (gl->gl_ops->go_flags & GLOF_ASPACE) { |
| kmem_cache_free(gfs2_glock_aspace_cachep, gl); |
| } else { |
| kfree(gl->gl_lksb.sb_lvbptr); |
| kmem_cache_free(gfs2_glock_cachep, gl); |
| } |
| } |
| |
| void gfs2_glock_free(struct gfs2_glock *gl) |
| { |
| struct gfs2_sbd *sdp = gl->gl_sbd; |
| |
| call_rcu(&gl->gl_rcu, gfs2_glock_dealloc); |
| if (atomic_dec_and_test(&sdp->sd_glock_disposal)) |
| wake_up(&sdp->sd_glock_wait); |
| } |
| |
| /** |
| * gfs2_glock_hold() - increment reference count on glock |
| * @gl: The glock to hold |
| * |
| */ |
| |
| void gfs2_glock_hold(struct gfs2_glock *gl) |
| { |
| GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0); |
| atomic_inc(&gl->gl_ref); |
| } |
| |
| /** |
| * demote_ok - Check to see if it's ok to unlock a glock |
| * @gl: the glock |
| * |
| * Returns: 1 if it's ok |
| */ |
| |
| static int demote_ok(const struct gfs2_glock *gl) |
| { |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| |
| if (gl->gl_state == LM_ST_UNLOCKED) |
| return 0; |
| if (!list_empty(&gl->gl_holders)) |
| return 0; |
| if (glops->go_demote_ok) |
| return glops->go_demote_ok(gl); |
| return 1; |
| } |
| |
| |
| void gfs2_glock_add_to_lru(struct gfs2_glock *gl) |
| { |
| spin_lock(&lru_lock); |
| |
| if (!list_empty(&gl->gl_lru)) |
| list_del_init(&gl->gl_lru); |
| else |
| atomic_inc(&lru_count); |
| |
| list_add_tail(&gl->gl_lru, &lru_list); |
| set_bit(GLF_LRU, &gl->gl_flags); |
| spin_unlock(&lru_lock); |
| } |
| |
| static void __gfs2_glock_remove_from_lru(struct gfs2_glock *gl) |
| { |
| if (!list_empty(&gl->gl_lru)) { |
| list_del_init(&gl->gl_lru); |
| atomic_dec(&lru_count); |
| clear_bit(GLF_LRU, &gl->gl_flags); |
| } |
| } |
| |
| static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl) |
| { |
| spin_lock(&lru_lock); |
| __gfs2_glock_remove_from_lru(gl); |
| spin_unlock(&lru_lock); |
| } |
| |
| /** |
| * gfs2_glock_put_nolock() - Decrement reference count on glock |
| * @gl: The glock to put |
| * |
| * This function should only be used if the caller has its own reference |
| * to the glock, in addition to the one it is dropping. |
| */ |
| |
| void gfs2_glock_put_nolock(struct gfs2_glock *gl) |
| { |
| if (atomic_dec_and_test(&gl->gl_ref)) |
| GLOCK_BUG_ON(gl, 1); |
| } |
| |
| /** |
| * gfs2_glock_put() - Decrement reference count on glock |
| * @gl: The glock to put |
| * |
| */ |
| |
| void gfs2_glock_put(struct gfs2_glock *gl) |
| { |
| struct gfs2_sbd *sdp = gl->gl_sbd; |
| struct address_space *mapping = gfs2_glock2aspace(gl); |
| |
| if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) { |
| __gfs2_glock_remove_from_lru(gl); |
| spin_unlock(&lru_lock); |
| spin_lock_bucket(gl->gl_hash); |
| hlist_bl_del_rcu(&gl->gl_list); |
| spin_unlock_bucket(gl->gl_hash); |
| GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
| GLOCK_BUG_ON(gl, mapping && mapping->nrpages); |
| trace_gfs2_glock_put(gl); |
| sdp->sd_lockstruct.ls_ops->lm_put_lock(gl); |
| } |
| } |
| |
| /** |
| * search_bucket() - Find struct gfs2_glock by lock number |
| * @bucket: the bucket to search |
| * @name: The lock name |
| * |
| * Returns: NULL, or the struct gfs2_glock with the requested number |
| */ |
| |
| static struct gfs2_glock *search_bucket(unsigned int hash, |
| const struct gfs2_sbd *sdp, |
| const struct lm_lockname *name) |
| { |
| struct gfs2_glock *gl; |
| struct hlist_bl_node *h; |
| |
| hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) { |
| if (!lm_name_equal(&gl->gl_name, name)) |
| continue; |
| if (gl->gl_sbd != sdp) |
| continue; |
| if (atomic_inc_not_zero(&gl->gl_ref)) |
| return gl; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * may_grant - check if its ok to grant a new lock |
| * @gl: The glock |
| * @gh: The lock request which we wish to grant |
| * |
| * Returns: true if its ok to grant the lock |
| */ |
| |
| static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) |
| { |
| const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); |
| if ((gh->gh_state == LM_ST_EXCLUSIVE || |
| gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) |
| return 0; |
| if (gl->gl_state == gh->gh_state) |
| return 1; |
| if (gh->gh_flags & GL_EXACT) |
| return 0; |
| if (gl->gl_state == LM_ST_EXCLUSIVE) { |
| if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) |
| return 1; |
| if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) |
| return 1; |
| } |
| if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
| return 1; |
| return 0; |
| } |
| |
| static void gfs2_holder_wake(struct gfs2_holder *gh) |
| { |
| clear_bit(HIF_WAIT, &gh->gh_iflags); |
| smp_mb__after_clear_bit(); |
| wake_up_bit(&gh->gh_iflags, HIF_WAIT); |
| } |
| |
| /** |
| * do_error - Something unexpected has happened during a lock request |
| * |
| */ |
| |
| static inline void do_error(struct gfs2_glock *gl, const int ret) |
| { |
| struct gfs2_holder *gh, *tmp; |
| |
| list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { |
| if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| continue; |
| if (ret & LM_OUT_ERROR) |
| gh->gh_error = -EIO; |
| else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) |
| gh->gh_error = GLR_TRYFAILED; |
| else |
| continue; |
| list_del_init(&gh->gh_list); |
| trace_gfs2_glock_queue(gh, 0); |
| gfs2_holder_wake(gh); |
| } |
| } |
| |
| /** |
| * do_promote - promote as many requests as possible on the current queue |
| * @gl: The glock |
| * |
| * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
| * if a type specific operation is underway. |
| */ |
| |
| static int do_promote(struct gfs2_glock *gl) |
| __releases(&gl->gl_spin) |
| __acquires(&gl->gl_spin) |
| { |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| struct gfs2_holder *gh, *tmp; |
| int ret; |
| |
| restart: |
| list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { |
| if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| continue; |
| if (may_grant(gl, gh)) { |
| if (gh->gh_list.prev == &gl->gl_holders && |
| glops->go_lock) { |
| spin_unlock(&gl->gl_spin); |
| /* FIXME: eliminate this eventually */ |
| ret = glops->go_lock(gh); |
| spin_lock(&gl->gl_spin); |
| if (ret) { |
| if (ret == 1) |
| return 2; |
| gh->gh_error = ret; |
| list_del_init(&gh->gh_list); |
| trace_gfs2_glock_queue(gh, 0); |
| gfs2_holder_wake(gh); |
| goto restart; |
| } |
| set_bit(HIF_HOLDER, &gh->gh_iflags); |
| trace_gfs2_promote(gh, 1); |
| gfs2_holder_wake(gh); |
| goto restart; |
| } |
| set_bit(HIF_HOLDER, &gh->gh_iflags); |
| trace_gfs2_promote(gh, 0); |
| gfs2_holder_wake(gh); |
| continue; |
| } |
| if (gh->gh_list.prev == &gl->gl_holders) |
| return 1; |
| do_error(gl, 0); |
| break; |
| } |
| return 0; |
| } |
| |
| /** |
| * find_first_waiter - find the first gh that's waiting for the glock |
| * @gl: the glock |
| */ |
| |
| static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) |
| { |
| struct gfs2_holder *gh; |
| |
| list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
| if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| return gh; |
| } |
| return NULL; |
| } |
| |
| /** |
| * state_change - record that the glock is now in a different state |
| * @gl: the glock |
| * @new_state the new state |
| * |
| */ |
| |
| static void state_change(struct gfs2_glock *gl, unsigned int new_state) |
| { |
| int held1, held2; |
| |
| held1 = (gl->gl_state != LM_ST_UNLOCKED); |
| held2 = (new_state != LM_ST_UNLOCKED); |
| |
| if (held1 != held2) { |
| if (held2) |
| gfs2_glock_hold(gl); |
| else |
| gfs2_glock_put_nolock(gl); |
| } |
| if (held1 && held2 && list_empty(&gl->gl_holders)) |
| clear_bit(GLF_QUEUED, &gl->gl_flags); |
| |
| if (new_state != gl->gl_target) |
| /* shorten our minimum hold time */ |
| gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR, |
| GL_GLOCK_MIN_HOLD); |
| gl->gl_state = new_state; |
| gl->gl_tchange = jiffies; |
| } |
| |
| static void gfs2_demote_wake(struct gfs2_glock *gl) |
| { |
| gl->gl_demote_state = LM_ST_EXCLUSIVE; |
| clear_bit(GLF_DEMOTE, &gl->gl_flags); |
| smp_mb__after_clear_bit(); |
| wake_up_bit(&gl->gl_flags, GLF_DEMOTE); |
| } |
| |
| /** |
| * finish_xmote - The DLM has replied to one of our lock requests |
| * @gl: The glock |
| * @ret: The status from the DLM |
| * |
| */ |
| |
| static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) |
| { |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| struct gfs2_holder *gh; |
| unsigned state = ret & LM_OUT_ST_MASK; |
| int rv; |
| |
| spin_lock(&gl->gl_spin); |
| trace_gfs2_glock_state_change(gl, state); |
| state_change(gl, state); |
| gh = find_first_waiter(gl); |
| |
| /* Demote to UN request arrived during demote to SH or DF */ |
| if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && |
| state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) |
| gl->gl_target = LM_ST_UNLOCKED; |
| |
| /* Check for state != intended state */ |
| if (unlikely(state != gl->gl_target)) { |
| if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { |
| /* move to back of queue and try next entry */ |
| if (ret & LM_OUT_CANCELED) { |
| if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) |
| list_move_tail(&gh->gh_list, &gl->gl_holders); |
| gh = find_first_waiter(gl); |
| gl->gl_target = gh->gh_state; |
| goto retry; |
| } |
| /* Some error or failed "try lock" - report it */ |
| if ((ret & LM_OUT_ERROR) || |
| (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { |
| gl->gl_target = gl->gl_state; |
| do_error(gl, ret); |
| goto out; |
| } |
| } |
| switch(state) { |
| /* Unlocked due to conversion deadlock, try again */ |
| case LM_ST_UNLOCKED: |
| retry: |
| do_xmote(gl, gh, gl->gl_target); |
| break; |
| /* Conversion fails, unlock and try again */ |
| case LM_ST_SHARED: |
| case LM_ST_DEFERRED: |
| do_xmote(gl, gh, LM_ST_UNLOCKED); |
| break; |
| default: /* Everything else */ |
| printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); |
| GLOCK_BUG_ON(gl, 1); |
| } |
| spin_unlock(&gl->gl_spin); |
| return; |
| } |
| |
| /* Fast path - we got what we asked for */ |
| if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) |
| gfs2_demote_wake(gl); |
| if (state != LM_ST_UNLOCKED) { |
| if (glops->go_xmote_bh) { |
| spin_unlock(&gl->gl_spin); |
| rv = glops->go_xmote_bh(gl, gh); |
| spin_lock(&gl->gl_spin); |
| if (rv) { |
| do_error(gl, rv); |
| goto out; |
| } |
| } |
| rv = do_promote(gl); |
| if (rv == 2) |
| goto out_locked; |
| } |
| out: |
| clear_bit(GLF_LOCK, &gl->gl_flags); |
| out_locked: |
| spin_unlock(&gl->gl_spin); |
| } |
| |
| /** |
| * do_xmote - Calls the DLM to change the state of a lock |
| * @gl: The lock state |
| * @gh: The holder (only for promotes) |
| * @target: The target lock state |
| * |
| */ |
| |
| static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) |
| __releases(&gl->gl_spin) |
| __acquires(&gl->gl_spin) |
| { |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| struct gfs2_sbd *sdp = gl->gl_sbd; |
| unsigned int lck_flags = gh ? gh->gh_flags : 0; |
| int ret; |
| |
| lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | |
| LM_FLAG_PRIORITY); |
| GLOCK_BUG_ON(gl, gl->gl_state == target); |
| GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target); |
| if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && |
| glops->go_inval) { |
| set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); |
| do_error(gl, 0); /* Fail queued try locks */ |
| } |
| gl->gl_req = target; |
| set_bit(GLF_BLOCKING, &gl->gl_flags); |
| if ((gl->gl_req == LM_ST_UNLOCKED) || |
| (gl->gl_state == LM_ST_EXCLUSIVE) || |
| (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB))) |
| clear_bit(GLF_BLOCKING, &gl->gl_flags); |
| spin_unlock(&gl->gl_spin); |
| if (glops->go_sync) |
| glops->go_sync(gl); |
| if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) |
| glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); |
| clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); |
| |
| gfs2_glock_hold(gl); |
| if (sdp->sd_lockstruct.ls_ops->lm_lock) { |
| /* lock_dlm */ |
| ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags); |
| if (ret) { |
| printk(KERN_ERR "GFS2: lm_lock ret %d\n", ret); |
| GLOCK_BUG_ON(gl, 1); |
| } |
| } else { /* lock_nolock */ |
| finish_xmote(gl, target); |
| if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| gfs2_glock_put(gl); |
| } |
| |
| spin_lock(&gl->gl_spin); |
| } |
| |
| /** |
| * find_first_holder - find the first "holder" gh |
| * @gl: the glock |
| */ |
| |
| static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) |
| { |
| struct gfs2_holder *gh; |
| |
| if (!list_empty(&gl->gl_holders)) { |
| gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); |
| if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| return gh; |
| } |
| return NULL; |
| } |
| |
| /** |
| * run_queue - do all outstanding tasks related to a glock |
| * @gl: The glock in question |
| * @nonblock: True if we must not block in run_queue |
| * |
| */ |
| |
| static void run_queue(struct gfs2_glock *gl, const int nonblock) |
| __releases(&gl->gl_spin) |
| __acquires(&gl->gl_spin) |
| { |
| struct gfs2_holder *gh = NULL; |
| int ret; |
| |
| if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) |
| return; |
| |
| GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); |
| |
| if (test_bit(GLF_DEMOTE, &gl->gl_flags) && |
| gl->gl_demote_state != gl->gl_state) { |
| if (find_first_holder(gl)) |
| goto out_unlock; |
| if (nonblock) |
| goto out_sched; |
| set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); |
| GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
| gl->gl_target = gl->gl_demote_state; |
| } else { |
| if (test_bit(GLF_DEMOTE, &gl->gl_flags)) |
| gfs2_demote_wake(gl); |
| ret = do_promote(gl); |
| if (ret == 0) |
| goto out_unlock; |
| if (ret == 2) |
| goto out; |
| gh = find_first_waiter(gl); |
| gl->gl_target = gh->gh_state; |
| if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) |
| do_error(gl, 0); /* Fail queued try locks */ |
| } |
| do_xmote(gl, gh, gl->gl_target); |
| out: |
| return; |
| |
| out_sched: |
| clear_bit(GLF_LOCK, &gl->gl_flags); |
| smp_mb__after_clear_bit(); |
| gfs2_glock_hold(gl); |
| if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| gfs2_glock_put_nolock(gl); |
| return; |
| |
| out_unlock: |
| clear_bit(GLF_LOCK, &gl->gl_flags); |
| smp_mb__after_clear_bit(); |
| return; |
| } |
| |
| static void delete_work_func(struct work_struct *work) |
| { |
| struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete); |
| struct gfs2_sbd *sdp = gl->gl_sbd; |
| struct gfs2_inode *ip; |
| struct inode *inode; |
| u64 no_addr = gl->gl_name.ln_number; |
| |
| ip = gl->gl_object; |
| /* Note: Unsafe to dereference ip as we don't hold right refs/locks */ |
| |
| if (ip) |
| inode = gfs2_ilookup(sdp->sd_vfs, no_addr, 1); |
| else |
| inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED); |
| if (inode && !IS_ERR(inode)) { |
| d_prune_aliases(inode); |
| iput(inode); |
| } |
| gfs2_glock_put(gl); |
| } |
| |
| static void glock_work_func(struct work_struct *work) |
| { |
| unsigned long delay = 0; |
| struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
| int drop_ref = 0; |
| |
| if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) { |
| finish_xmote(gl, gl->gl_reply); |
| drop_ref = 1; |
| } |
| spin_lock(&gl->gl_spin); |
| if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
| gl->gl_state != LM_ST_UNLOCKED && |
| gl->gl_demote_state != LM_ST_EXCLUSIVE) { |
| unsigned long holdtime, now = jiffies; |
| |
| holdtime = gl->gl_tchange + gl->gl_hold_time; |
| if (time_before(now, holdtime)) |
| delay = holdtime - now; |
| |
| if (!delay) { |
| clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags); |
| set_bit(GLF_DEMOTE, &gl->gl_flags); |
| } |
| } |
| run_queue(gl, 0); |
| spin_unlock(&gl->gl_spin); |
| if (!delay) |
| gfs2_glock_put(gl); |
| else { |
| if (gl->gl_name.ln_type != LM_TYPE_INODE) |
| delay = 0; |
| if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
| gfs2_glock_put(gl); |
| } |
| if (drop_ref) |
| gfs2_glock_put(gl); |
| } |
| |
| /** |
| * gfs2_glock_get() - Get a glock, or create one if one doesn't exist |
| * @sdp: The GFS2 superblock |
| * @number: the lock number |
| * @glops: The glock_operations to use |
| * @create: If 0, don't create the glock if it doesn't exist |
| * @glp: the glock is returned here |
| * |
| * This does not lock a glock, just finds/creates structures for one. |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
| const struct gfs2_glock_operations *glops, int create, |
| struct gfs2_glock **glp) |
| { |
| struct super_block *s = sdp->sd_vfs; |
| struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
| struct gfs2_glock *gl, *tmp; |
| unsigned int hash = gl_hash(sdp, &name); |
| struct address_space *mapping; |
| struct kmem_cache *cachep; |
| |
| rcu_read_lock(); |
| gl = search_bucket(hash, sdp, &name); |
| rcu_read_unlock(); |
| |
| *glp = gl; |
| if (gl) |
| return 0; |
| if (!create) |
| return -ENOENT; |
| |
| if (glops->go_flags & GLOF_ASPACE) |
| cachep = gfs2_glock_aspace_cachep; |
| else |
| cachep = gfs2_glock_cachep; |
| gl = kmem_cache_alloc(cachep, GFP_KERNEL); |
| if (!gl) |
| return -ENOMEM; |
| |
| memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); |
| |
| if (glops->go_flags & GLOF_LVB) { |
| gl->gl_lksb.sb_lvbptr = kzalloc(GFS2_MIN_LVB_SIZE, GFP_KERNEL); |
| if (!gl->gl_lksb.sb_lvbptr) { |
| kmem_cache_free(cachep, gl); |
| return -ENOMEM; |
| } |
| } |
| |
| atomic_inc(&sdp->sd_glock_disposal); |
| gl->gl_sbd = sdp; |
| gl->gl_flags = 0; |
| gl->gl_name = name; |
| atomic_set(&gl->gl_ref, 1); |
| gl->gl_state = LM_ST_UNLOCKED; |
| gl->gl_target = LM_ST_UNLOCKED; |
| gl->gl_demote_state = LM_ST_EXCLUSIVE; |
| gl->gl_hash = hash; |
| gl->gl_ops = glops; |
| gl->gl_dstamp = ktime_set(0, 0); |
| preempt_disable(); |
| /* We use the global stats to estimate the initial per-glock stats */ |
| gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type]; |
| preempt_enable(); |
| gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0; |
| gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0; |
| gl->gl_tchange = jiffies; |
| gl->gl_object = NULL; |
| gl->gl_hold_time = GL_GLOCK_DFT_HOLD; |
| INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
| INIT_WORK(&gl->gl_delete, delete_work_func); |
| |
| mapping = gfs2_glock2aspace(gl); |
| if (mapping) { |
| mapping->a_ops = &gfs2_meta_aops; |
| mapping->host = s->s_bdev->bd_inode; |
| mapping->flags = 0; |
| mapping_set_gfp_mask(mapping, GFP_NOFS); |
| mapping->private_data = NULL; |
| mapping->backing_dev_info = s->s_bdi; |
| mapping->writeback_index = 0; |
| } |
| |
| spin_lock_bucket(hash); |
| tmp = search_bucket(hash, sdp, &name); |
| if (tmp) { |
| spin_unlock_bucket(hash); |
| kfree(gl->gl_lksb.sb_lvbptr); |
| kmem_cache_free(cachep, gl); |
| atomic_dec(&sdp->sd_glock_disposal); |
| gl = tmp; |
| } else { |
| hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]); |
| spin_unlock_bucket(hash); |
| } |
| |
| *glp = gl; |
| |
| return 0; |
| } |
| |
| /** |
| * gfs2_holder_init - initialize a struct gfs2_holder in the default way |
| * @gl: the glock |
| * @state: the state we're requesting |
| * @flags: the modifier flags |
| * @gh: the holder structure |
| * |
| */ |
| |
| void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
| struct gfs2_holder *gh) |
| { |
| INIT_LIST_HEAD(&gh->gh_list); |
| gh->gh_gl = gl; |
| gh->gh_ip = (unsigned long)__builtin_return_address(0); |
| gh->gh_owner_pid = get_pid(task_pid(current)); |
| gh->gh_state = state; |
| gh->gh_flags = flags; |
| gh->gh_error = 0; |
| gh->gh_iflags = 0; |
| gfs2_glock_hold(gl); |
| } |
| |
| /** |
| * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it |
| * @state: the state we're requesting |
| * @flags: the modifier flags |
| * @gh: the holder structure |
| * |
| * Don't mess with the glock. |
| * |
| */ |
| |
| void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
| { |
| gh->gh_state = state; |
| gh->gh_flags = flags; |
| gh->gh_iflags = 0; |
| gh->gh_ip = (unsigned long)__builtin_return_address(0); |
| if (gh->gh_owner_pid) |
| put_pid(gh->gh_owner_pid); |
| gh->gh_owner_pid = get_pid(task_pid(current)); |
| } |
| |
| /** |
| * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) |
| * @gh: the holder structure |
| * |
| */ |
| |
| void gfs2_holder_uninit(struct gfs2_holder *gh) |
| { |
| put_pid(gh->gh_owner_pid); |
| gfs2_glock_put(gh->gh_gl); |
| gh->gh_gl = NULL; |
| gh->gh_ip = 0; |
| } |
| |
| /** |
| * gfs2_glock_holder_wait |
| * @word: unused |
| * |
| * This function and gfs2_glock_demote_wait both show up in the WCHAN |
| * field. Thus I've separated these otherwise identical functions in |
| * order to be more informative to the user. |
| */ |
| |
| static int gfs2_glock_holder_wait(void *word) |
| { |
| schedule(); |
| return 0; |
| } |
| |
| static int gfs2_glock_demote_wait(void *word) |
| { |
| schedule(); |
| return 0; |
| } |
| |
| /** |
| * gfs2_glock_wait - wait on a glock acquisition |
| * @gh: the glock holder |
| * |
| * Returns: 0 on success |
| */ |
| |
| int gfs2_glock_wait(struct gfs2_holder *gh) |
| { |
| unsigned long time1 = jiffies; |
| |
| might_sleep(); |
| wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE); |
| if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */ |
| /* Lengthen the minimum hold time. */ |
| gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time + |
| GL_GLOCK_HOLD_INCR, |
| GL_GLOCK_MAX_HOLD); |
| return gh->gh_error; |
| } |
| |
| /** |
| * handle_callback - process a demote request |
| * @gl: the glock |
| * @state: the state the caller wants us to change to |
| * |
| * There are only two requests that we are going to see in actual |
| * practise: LM_ST_SHARED and LM_ST_UNLOCKED |
| */ |
| |
| static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
| unsigned long delay, bool remote) |
| { |
| int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
| |
| set_bit(bit, &gl->gl_flags); |
| if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { |
| gl->gl_demote_state = state; |
| gl->gl_demote_time = jiffies; |
| } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
| gl->gl_demote_state != state) { |
| gl->gl_demote_state = LM_ST_UNLOCKED; |
| } |
| if (gl->gl_ops->go_callback) |
| gl->gl_ops->go_callback(gl, remote); |
| trace_gfs2_demote_rq(gl, remote); |
| } |
| |
| void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
| { |
| struct va_format vaf; |
| va_list args; |
| |
| va_start(args, fmt); |
| |
| if (seq) { |
| seq_vprintf(seq, fmt, args); |
| } else { |
| vaf.fmt = fmt; |
| vaf.va = &args; |
| |
| printk(KERN_ERR " %pV", &vaf); |
| } |
| |
| va_end(args); |
| } |
| |
| /** |
| * add_to_queue - Add a holder to the wait queue (but look for recursion) |
| * @gh: the holder structure to add |
| * |
| * Eventually we should move the recursive locking trap to a |
| * debugging option or something like that. This is the fast |
| * path and needs to have the minimum number of distractions. |
| * |
| */ |
| |
| static inline void add_to_queue(struct gfs2_holder *gh) |
| __releases(&gl->gl_spin) |
| __acquires(&gl->gl_spin) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| struct gfs2_sbd *sdp = gl->gl_sbd; |
| struct list_head *insert_pt = NULL; |
| struct gfs2_holder *gh2; |
| int try_futile = 0; |
| |
| BUG_ON(gh->gh_owner_pid == NULL); |
| if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
| BUG(); |
| |
| if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
| if (test_bit(GLF_LOCK, &gl->gl_flags)) |
| try_futile = !may_grant(gl, gh); |
| if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) |
| goto fail; |
| } |
| |
| list_for_each_entry(gh2, &gl->gl_holders, gh_list) { |
| if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && |
| (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) |
| goto trap_recursive; |
| if (try_futile && |
| !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { |
| fail: |
| gh->gh_error = GLR_TRYFAILED; |
| gfs2_holder_wake(gh); |
| return; |
| } |
| if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
| continue; |
| if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) |
| insert_pt = &gh2->gh_list; |
| } |
| set_bit(GLF_QUEUED, &gl->gl_flags); |
| trace_gfs2_glock_queue(gh, 1); |
| gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT); |
| gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT); |
| if (likely(insert_pt == NULL)) { |
| list_add_tail(&gh->gh_list, &gl->gl_holders); |
| if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) |
| goto do_cancel; |
| return; |
| } |
| list_add_tail(&gh->gh_list, insert_pt); |
| do_cancel: |
| gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); |
| if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { |
| spin_unlock(&gl->gl_spin); |
| if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
| sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
| spin_lock(&gl->gl_spin); |
| } |
| return; |
| |
| trap_recursive: |
| printk(KERN_ERR "original: %pSR\n", (void *)gh2->gh_ip); |
| printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); |
| printk(KERN_ERR "lock type: %d req lock state : %d\n", |
| gh2->gh_gl->gl_name.ln_type, gh2->gh_state); |
| printk(KERN_ERR "new: %pSR\n", (void *)gh->gh_ip); |
| printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); |
| printk(KERN_ERR "lock type: %d req lock state : %d\n", |
| gh->gh_gl->gl_name.ln_type, gh->gh_state); |
| gfs2_dump_glock(NULL, gl); |
| BUG(); |
| } |
| |
| /** |
| * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) |
| * @gh: the holder structure |
| * |
| * if (gh->gh_flags & GL_ASYNC), this never returns an error |
| * |
| * Returns: 0, GLR_TRYFAILED, or errno on failure |
| */ |
| |
| int gfs2_glock_nq(struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| struct gfs2_sbd *sdp = gl->gl_sbd; |
| int error = 0; |
| |
| if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
| return -EIO; |
| |
| if (test_bit(GLF_LRU, &gl->gl_flags)) |
| gfs2_glock_remove_from_lru(gl); |
| |
| spin_lock(&gl->gl_spin); |
| add_to_queue(gh); |
| if ((LM_FLAG_NOEXP & gh->gh_flags) && |
| test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) |
| set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
| run_queue(gl, 1); |
| spin_unlock(&gl->gl_spin); |
| |
| if (!(gh->gh_flags & GL_ASYNC)) |
| error = gfs2_glock_wait(gh); |
| |
| return error; |
| } |
| |
| /** |
| * gfs2_glock_poll - poll to see if an async request has been completed |
| * @gh: the holder |
| * |
| * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on |
| */ |
| |
| int gfs2_glock_poll(struct gfs2_holder *gh) |
| { |
| return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
| } |
| |
| /** |
| * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) |
| * @gh: the glock holder |
| * |
| */ |
| |
| void gfs2_glock_dq(struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| unsigned delay = 0; |
| int fast_path = 0; |
| |
| spin_lock(&gl->gl_spin); |
| if (gh->gh_flags & GL_NOCACHE) |
| handle_callback(gl, LM_ST_UNLOCKED, 0, false); |
| |
| list_del_init(&gh->gh_list); |
| if (find_first_holder(gl) == NULL) { |
| if (glops->go_unlock) { |
| GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
| spin_unlock(&gl->gl_spin); |
| glops->go_unlock(gh); |
| spin_lock(&gl->gl_spin); |
| clear_bit(GLF_LOCK, &gl->gl_flags); |
| } |
| if (list_empty(&gl->gl_holders) && |
| !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
| !test_bit(GLF_DEMOTE, &gl->gl_flags)) |
| fast_path = 1; |
| } |
| if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl)) |
| gfs2_glock_add_to_lru(gl); |
| |
| trace_gfs2_glock_queue(gh, 0); |
| spin_unlock(&gl->gl_spin); |
| if (likely(fast_path)) |
| return; |
| |
| gfs2_glock_hold(gl); |
| if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
| !test_bit(GLF_DEMOTE, &gl->gl_flags) && |
| gl->gl_name.ln_type == LM_TYPE_INODE) |
| delay = gl->gl_hold_time; |
| if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
| gfs2_glock_put(gl); |
| } |
| |
| void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| gfs2_glock_dq(gh); |
| might_sleep(); |
| wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE); |
| } |
| |
| /** |
| * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it |
| * @gh: the holder structure |
| * |
| */ |
| |
| void gfs2_glock_dq_uninit(struct gfs2_holder *gh) |
| { |
| gfs2_glock_dq(gh); |
| gfs2_holder_uninit(gh); |
| } |
| |
| /** |
| * gfs2_glock_nq_num - acquire a glock based on lock number |
| * @sdp: the filesystem |
| * @number: the lock number |
| * @glops: the glock operations for the type of glock |
| * @state: the state to acquire the glock in |
| * @flags: modifier flags for the acquisition |
| * @gh: the struct gfs2_holder |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
| const struct gfs2_glock_operations *glops, |
| unsigned int state, int flags, struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl; |
| int error; |
| |
| error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); |
| if (!error) { |
| error = gfs2_glock_nq_init(gl, state, flags, gh); |
| gfs2_glock_put(gl); |
| } |
| |
| return error; |
| } |
| |
| /** |
| * glock_compare - Compare two struct gfs2_glock structures for sorting |
| * @arg_a: the first structure |
| * @arg_b: the second structure |
| * |
| */ |
| |
| static int glock_compare(const void *arg_a, const void *arg_b) |
| { |
| const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
| const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; |
| const struct lm_lockname *a = &gh_a->gh_gl->gl_name; |
| const struct lm_lockname *b = &gh_b->gh_gl->gl_name; |
| |
| if (a->ln_number > b->ln_number) |
| return 1; |
| if (a->ln_number < b->ln_number) |
| return -1; |
| BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
| return 0; |
| } |
| |
| /** |
| * nq_m_sync - synchonously acquire more than one glock in deadlock free order |
| * @num_gh: the number of structures |
| * @ghs: an array of struct gfs2_holder structures |
| * |
| * Returns: 0 on success (all glocks acquired), |
| * errno on failure (no glocks acquired) |
| */ |
| |
| static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, |
| struct gfs2_holder **p) |
| { |
| unsigned int x; |
| int error = 0; |
| |
| for (x = 0; x < num_gh; x++) |
| p[x] = &ghs[x]; |
| |
| sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); |
| |
| for (x = 0; x < num_gh; x++) { |
| p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
| |
| error = gfs2_glock_nq(p[x]); |
| if (error) { |
| while (x--) |
| gfs2_glock_dq(p[x]); |
| break; |
| } |
| } |
| |
| return error; |
| } |
| |
| /** |
| * gfs2_glock_nq_m - acquire multiple glocks |
| * @num_gh: the number of structures |
| * @ghs: an array of struct gfs2_holder structures |
| * |
| * |
| * Returns: 0 on success (all glocks acquired), |
| * errno on failure (no glocks acquired) |
| */ |
| |
| int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) |
| { |
| struct gfs2_holder *tmp[4]; |
| struct gfs2_holder **pph = tmp; |
| int error = 0; |
| |
| switch(num_gh) { |
| case 0: |
| return 0; |
| case 1: |
| ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
| return gfs2_glock_nq(ghs); |
| default: |
| if (num_gh <= 4) |
| break; |
| pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
| if (!pph) |
| return -ENOMEM; |
| } |
| |
| error = nq_m_sync(num_gh, ghs, pph); |
| |
| if (pph != tmp) |
| kfree(pph); |
| |
| return error; |
| } |
| |
| /** |
| * gfs2_glock_dq_m - release multiple glocks |
| * @num_gh: the number of structures |
| * @ghs: an array of struct gfs2_holder structures |
| * |
| */ |
| |
| void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) |
| { |
| while (num_gh--) |
| gfs2_glock_dq(&ghs[num_gh]); |
| } |
| |
| void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
| { |
| unsigned long delay = 0; |
| unsigned long holdtime; |
| unsigned long now = jiffies; |
| |
| gfs2_glock_hold(gl); |
| holdtime = gl->gl_tchange + gl->gl_hold_time; |
| if (test_bit(GLF_QUEUED, &gl->gl_flags) && |
| gl->gl_name.ln_type == LM_TYPE_INODE) { |
| if (time_before(now, holdtime)) |
| delay = holdtime - now; |
| if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
| delay = gl->gl_hold_time; |
| } |
| |
| spin_lock(&gl->gl_spin); |
| handle_callback(gl, state, delay, true); |
| spin_unlock(&gl->gl_spin); |
| if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
| gfs2_glock_put(gl); |
| } |
| |
| /** |
| * gfs2_should_freeze - Figure out if glock should be frozen |
| * @gl: The glock in question |
| * |
| * Glocks are not frozen if (a) the result of the dlm operation is |
| * an error, (b) the locking operation was an unlock operation or |
| * (c) if there is a "noexp" flagged request anywhere in the queue |
| * |
| * Returns: 1 if freezing should occur, 0 otherwise |
| */ |
| |
| static int gfs2_should_freeze(const struct gfs2_glock *gl) |
| { |
| const struct gfs2_holder *gh; |
| |
| if (gl->gl_reply & ~LM_OUT_ST_MASK) |
| return 0; |
| if (gl->gl_target == LM_ST_UNLOCKED) |
| return 0; |
| |
| list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
| if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| continue; |
| if (LM_FLAG_NOEXP & gh->gh_flags) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /** |
| * gfs2_glock_complete - Callback used by locking |
| * @gl: Pointer to the glock |
| * @ret: The return value from the dlm |
| * |
| * The gl_reply field is under the gl_spin lock so that it is ok |
| * to use a bitfield shared with other glock state fields. |
| */ |
| |
| void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
| { |
| struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; |
| |
| spin_lock(&gl->gl_spin); |
| gl->gl_reply = ret; |
| |
| if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) { |
| if (gfs2_should_freeze(gl)) { |
| set_bit(GLF_FROZEN, &gl->gl_flags); |
| spin_unlock(&gl->gl_spin); |
| return; |
| } |
| } |
| |
| spin_unlock(&gl->gl_spin); |
| set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
| smp_wmb(); |
| gfs2_glock_hold(gl); |
| if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| gfs2_glock_put(gl); |
| } |
| |
| static int glock_cmp(void *priv, struct list_head *a, struct list_head *b) |
| { |
| struct gfs2_glock *gla, *glb; |
| |
| gla = list_entry(a, struct gfs2_glock, gl_lru); |
| glb = list_entry(b, struct gfs2_glock, gl_lru); |
| |
| if (gla->gl_name.ln_number > glb->gl_name.ln_number) |
| return 1; |
| if (gla->gl_name.ln_number < glb->gl_name.ln_number) |
| return -1; |
| |
| return 0; |
| } |
| |
| /** |
| * gfs2_dispose_glock_lru - Demote a list of glocks |
| * @list: The list to dispose of |
| * |
| * Disposing of glocks may involve disk accesses, so that here we sort |
| * the glocks by number (i.e. disk location of the inodes) so that if |
| * there are any such accesses, they'll be sent in order (mostly). |
| * |
| * Must be called under the lru_lock, but may drop and retake this |
| * lock. While the lru_lock is dropped, entries may vanish from the |
| * list, but no new entries will appear on the list (since it is |
| * private) |
| */ |
| |
| static void gfs2_dispose_glock_lru(struct list_head *list) |
| __releases(&lru_lock) |
| __acquires(&lru_lock) |
| { |
| struct gfs2_glock *gl; |
| |
| list_sort(NULL, list, glock_cmp); |
| |
| while(!list_empty(list)) { |
| gl = list_entry(list->next, struct gfs2_glock, gl_lru); |
| list_del_init(&gl->gl_lru); |
| clear_bit(GLF_LRU, &gl->gl_flags); |
| gfs2_glock_hold(gl); |
| spin_unlock(&lru_lock); |
| spin_lock(&gl->gl_spin); |
| if (demote_ok(gl)) |
| handle_callback(gl, LM_ST_UNLOCKED, 0, false); |
| WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags)); |
| if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| gfs2_glock_put_nolock(gl); |
| spin_unlock(&gl->gl_spin); |
| spin_lock(&lru_lock); |
| } |
| } |
| |
| /** |
| * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote |
| * @nr: The number of entries to scan |
| * |
| * This function selects the entries on the LRU which are able to |
| * be demoted, and then kicks off the process by calling |
| * gfs2_dispose_glock_lru() above. |
| */ |
| |
| static void gfs2_scan_glock_lru(int nr) |
| { |
| struct gfs2_glock *gl; |
| LIST_HEAD(skipped); |
| LIST_HEAD(dispose); |
| |
| spin_lock(&lru_lock); |
| while(nr && !list_empty(&lru_list)) { |
| gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); |
| |
| /* Test for being demotable */ |
| if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
| list_move(&gl->gl_lru, &dispose); |
| atomic_dec(&lru_count); |
| nr--; |
| continue; |
| } |
| |
| list_move(&gl->gl_lru, &skipped); |
| } |
| list_splice(&skipped, &lru_list); |
| if (!list_empty(&dispose)) |
| gfs2_dispose_glock_lru(&dispose); |
| spin_unlock(&lru_lock); |
| } |
| |
| static int gfs2_shrink_glock_memory(struct shrinker *shrink, |
| struct shrink_control *sc) |
| { |
| if (sc->nr_to_scan) { |
| if (!(sc->gfp_mask & __GFP_FS)) |
| return -1; |
| gfs2_scan_glock_lru(sc->nr_to_scan); |
| } |
| |
| return vfs_pressure_ratio(atomic_read(&lru_count)); |
| } |
| |
| static struct shrinker glock_shrinker = { |
| .shrink = gfs2_shrink_glock_memory, |
| .seeks = DEFAULT_SEEKS, |
| }; |
| |
| /** |
| * examine_bucket - Call a function for glock in a hash bucket |
| * @examiner: the function |
| * @sdp: the filesystem |
| * @bucket: the bucket |
| * |
| */ |
| |
| static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp, |
| unsigned int hash) |
| { |
| struct gfs2_glock *gl; |
| struct hlist_bl_head *head = &gl_hash_table[hash]; |
| struct hlist_bl_node *pos; |
| |
| rcu_read_lock(); |
| hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) { |
| if ((gl->gl_sbd == sdp) && atomic_inc_not_zero(&gl->gl_ref)) |
| examiner(gl); |
| } |
| rcu_read_unlock(); |
| cond_resched(); |
| } |
| |
| static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp) |
| { |
| unsigned x; |
| |
| for (x = 0; x < GFS2_GL_HASH_SIZE; x++) |
| examine_bucket(examiner, sdp, x); |
| } |
| |
| |
| /** |
| * thaw_glock - thaw out a glock which has an unprocessed reply waiting |
| * @gl: The glock to thaw |
| * |
| */ |
| |
| static void thaw_glock(struct gfs2_glock *gl) |
| { |
| if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) |
| goto out; |
| set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
| if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) { |
| out: |
| gfs2_glock_put(gl); |
| } |
| } |
| |
| /** |
| * clear_glock - look at a glock and see if we can free it from glock cache |
| * @gl: the glock to look at |
| * |
| */ |
| |
| static void clear_glock(struct gfs2_glock *gl) |
| { |
| gfs2_glock_remove_from_lru(gl); |
| |
| spin_lock(&gl->gl_spin); |
| if (gl->gl_state != LM_ST_UNLOCKED) |
| handle_callback(gl, LM_ST_UNLOCKED, 0, false); |
| spin_unlock(&gl->gl_spin); |
| if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
| gfs2_glock_put(gl); |
| } |
| |
| /** |
| * gfs2_glock_thaw - Thaw any frozen glocks |
| * @sdp: The super block |
| * |
| */ |
| |
| void gfs2_glock_thaw(struct gfs2_sbd *sdp) |
| { |
| glock_hash_walk(thaw_glock, sdp); |
| } |
| |
| static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
| { |
| int ret; |
| spin_lock(&gl->gl_spin); |
| ret = gfs2_dump_glock(seq, gl); |
| spin_unlock(&gl->gl_spin); |
| return ret; |
| } |
| |
| static void dump_glock_func(struct gfs2_glock *gl) |
| { |
| dump_glock(NULL, gl); |
| } |
| |
| /** |
| * gfs2_gl_hash_clear - Empty out the glock hash table |
| * @sdp: the filesystem |
| * @wait: wait until it's all gone |
| * |
| * Called when unmounting the filesystem. |
| */ |
| |
| void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
| { |
| set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags); |
| flush_workqueue(glock_workqueue); |
| glock_hash_walk(clear_glock, sdp); |
| flush_workqueue(glock_workqueue); |
| wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0); |
| glock_hash_walk(dump_glock_func, sdp); |
| } |
| |
| void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
| { |
| struct gfs2_glock *gl = ip->i_gl; |
| int ret; |
| |
| ret = gfs2_truncatei_resume(ip); |
| gfs2_assert_withdraw(gl->gl_sbd, ret == 0); |
| |
| spin_lock(&gl->gl_spin); |
| clear_bit(GLF_LOCK, &gl->gl_flags); |
| run_queue(gl, 1); |
| spin_unlock(&gl->gl_spin); |
| } |
| |
| static const char *state2str(unsigned state) |
| { |
| switch(state) { |
| case LM_ST_UNLOCKED: |
| return "UN"; |
| case LM_ST_SHARED: |
| return "SH"; |
| case LM_ST_DEFERRED: |
| return "DF"; |
| case LM_ST_EXCLUSIVE: |
| return "EX"; |
| } |
| return "??"; |
| } |
| |
| static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) |
| { |
| char *p = buf; |
| if (flags & LM_FLAG_TRY) |
| *p++ = 't'; |
| if (flags & LM_FLAG_TRY_1CB) |
| *p++ = 'T'; |
| if (flags & LM_FLAG_NOEXP) |
| *p++ = 'e'; |
| if (flags & LM_FLAG_ANY) |
| *p++ = 'A'; |
| if (flags & LM_FLAG_PRIORITY) |
| *p++ = 'p'; |
| if (flags & GL_ASYNC) |
| *p++ = 'a'; |
| if (flags & GL_EXACT) |
| *p++ = 'E'; |
| if (flags & GL_NOCACHE) |
| *p++ = 'c'; |
| if (test_bit(HIF_HOLDER, &iflags)) |
| *p++ = 'H'; |
| if (test_bit(HIF_WAIT, &iflags)) |
| *p++ = 'W'; |
| if (test_bit(HIF_FIRST, &iflags)) |
| *p++ = 'F'; |
| *p = 0; |
| return buf; |
| } |
| |
| /** |
| * dump_holder - print information about a glock holder |
| * @seq: the seq_file struct |
| * @gh: the glock holder |
| * |
| * Returns: 0 on success, -ENOBUFS when we run out of space |
| */ |
| |
| static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
| { |
| struct task_struct *gh_owner = NULL; |
| char flags_buf[32]; |
| |
| if (gh->gh_owner_pid) |
| gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
| gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n", |
| state2str(gh->gh_state), |
| hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), |
| gh->gh_error, |
| gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, |
| gh_owner ? gh_owner->comm : "(ended)", |
| (void *)gh->gh_ip); |
| return 0; |
| } |
| |
| static const char *gflags2str(char *buf, const struct gfs2_glock *gl) |
| { |
| const unsigned long *gflags = &gl->gl_flags; |
| char *p = buf; |
| |
| if (test_bit(GLF_LOCK, gflags)) |
| *p++ = 'l'; |
| if (test_bit(GLF_DEMOTE, gflags)) |
| *p++ = 'D'; |
| if (test_bit(GLF_PENDING_DEMOTE, gflags)) |
| *p++ = 'd'; |
| if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) |
| *p++ = 'p'; |
| if (test_bit(GLF_DIRTY, gflags)) |
| *p++ = 'y'; |
| if (test_bit(GLF_LFLUSH, gflags)) |
| *p++ = 'f'; |
| if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) |
| *p++ = 'i'; |
| if (test_bit(GLF_REPLY_PENDING, gflags)) |
| *p++ = 'r'; |
| if (test_bit(GLF_INITIAL, gflags)) |
| *p++ = 'I'; |
| if (test_bit(GLF_FROZEN, gflags)) |
| *p++ = 'F'; |
| if (test_bit(GLF_QUEUED, gflags)) |
| *p++ = 'q'; |
| if (test_bit(GLF_LRU, gflags)) |
| *p++ = 'L'; |
| if (gl->gl_object) |
| *p++ = 'o'; |
| if (test_bit(GLF_BLOCKING, gflags)) |
| *p++ = 'b'; |
| *p = 0; |
| return buf; |
| } |
| |
| /** |
| * gfs2_dump_glock - print information about a glock |
| * @seq: The seq_file struct |
| * @gl: the glock |
| * |
| * The file format is as follows: |
| * One line per object, capital letters are used to indicate objects |
| * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, |
| * other objects are indented by a single space and follow the glock to |
| * which they are related. Fields are indicated by lower case letters |
| * followed by a colon and the field value, except for strings which are in |
| * [] so that its possible to see if they are composed of spaces for |
| * example. The field's are n = number (id of the object), f = flags, |
| * t = type, s = state, r = refcount, e = error, p = pid. |
| * |
| * Returns: 0 on success, -ENOBUFS when we run out of space |
| */ |
| |
| int gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
| { |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| unsigned long long dtime; |
| const struct gfs2_holder *gh; |
| char gflags_buf[32]; |
| int error = 0; |
| |
| dtime = jiffies - gl->gl_demote_time; |
| dtime *= 1000000/HZ; /* demote time in uSec */ |
| if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) |
| dtime = 0; |
| gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d v:%d r:%d m:%ld\n", |
| state2str(gl->gl_state), |
| gl->gl_name.ln_type, |
| (unsigned long long)gl->gl_name.ln_number, |
| gflags2str(gflags_buf, gl), |
| state2str(gl->gl_target), |
| state2str(gl->gl_demote_state), dtime, |
| atomic_read(&gl->gl_ail_count), |
| atomic_read(&gl->gl_revokes), |
| atomic_read(&gl->gl_ref), gl->gl_hold_time); |
| |
| list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
| error = dump_holder(seq, gh); |
| if (error) |
| goto out; |
| } |
| if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
| error = glops->go_dump(seq, gl); |
| out: |
| return error; |
| } |
| |
| static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr) |
| { |
| struct gfs2_glock *gl = iter_ptr; |
| |
| seq_printf(seq, "G: n:%u/%llx rtt:%lld/%lld rttb:%lld/%lld irt:%lld/%lld dcnt: %lld qcnt: %lld\n", |
| gl->gl_name.ln_type, |
| (unsigned long long)gl->gl_name.ln_number, |
| (long long)gl->gl_stats.stats[GFS2_LKS_SRTT], |
| (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR], |
| (long long)gl->gl_stats.stats[GFS2_LKS_SRTTB], |
| (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB], |
| (long long)gl->gl_stats.stats[GFS2_LKS_SIRT], |
| (long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR], |
| (long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT], |
| (long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]); |
| return 0; |
| } |
| |
| static const char *gfs2_gltype[] = { |
| "type", |
| "reserved", |
| "nondisk", |
| "inode", |
| "rgrp", |
| "meta", |
| "iopen", |
| "flock", |
| "plock", |
| "quota", |
| "journal", |
| }; |
| |
| static const char *gfs2_stype[] = { |
| [GFS2_LKS_SRTT] = "srtt", |
| [GFS2_LKS_SRTTVAR] = "srttvar", |
| [GFS2_LKS_SRTTB] = "srttb", |
| [GFS2_LKS_SRTTVARB] = "srttvarb", |
| [GFS2_LKS_SIRT] = "sirt", |
| [GFS2_LKS_SIRTVAR] = "sirtvar", |
| [GFS2_LKS_DCOUNT] = "dlm", |
| [GFS2_LKS_QCOUNT] = "queue", |
| }; |
| |
| #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype)) |
| |
| static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr) |
| { |
| struct gfs2_glock_iter *gi = seq->private; |
| struct gfs2_sbd *sdp = gi->sdp; |
| unsigned index = gi->hash >> 3; |
| unsigned subindex = gi->hash & 0x07; |
| s64 value; |
| int i; |
| |
| if (index == 0 && subindex != 0) |
| return 0; |
| |
| seq_printf(seq, "%-10s %8s:", gfs2_gltype[index], |
| (index == 0) ? "cpu": gfs2_stype[subindex]); |
| |
| for_each_possible_cpu(i) { |
| const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i); |
| if (index == 0) { |
| value = i; |
| } else { |
| value = lkstats->lkstats[index - 1].stats[subindex]; |
| } |
| seq_printf(seq, " %15lld", (long long)value); |
| } |
| seq_putc(seq, '\n'); |
| return 0; |
| } |
| |
| int __init gfs2_glock_init(void) |
| { |
| unsigned i; |
| for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { |
| INIT_HLIST_BL_HEAD(&gl_hash_table[i]); |
| } |
| |
| glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM | |
| WQ_HIGHPRI | WQ_FREEZABLE, 0); |
| if (!glock_workqueue) |
| return -ENOMEM; |
| gfs2_delete_workqueue = alloc_workqueue("delete_workqueue", |
| WQ_MEM_RECLAIM | WQ_FREEZABLE, |
| 0); |
| if (!gfs2_delete_workqueue) { |
| destroy_workqueue(glock_workqueue); |
| return -ENOMEM; |
| } |
| |
| register_shrinker(&glock_shrinker); |
| |
| return 0; |
| } |
| |
| void gfs2_glock_exit(void) |
| { |
| unregister_shrinker(&glock_shrinker); |
| destroy_workqueue(glock_workqueue); |
| destroy_workqueue(gfs2_delete_workqueue); |
| } |
| |
| static inline struct gfs2_glock *glock_hash_chain(unsigned hash) |
| { |
| return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]), |
| struct gfs2_glock, gl_list); |
| } |
| |
| static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl) |
| { |
| return hlist_bl_entry(rcu_dereference(gl->gl_list.next), |
| struct gfs2_glock, gl_list); |
| } |
| |
| static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
| { |
| struct gfs2_glock *gl; |
| |
| do { |
| gl = gi->gl; |
| if (gl) { |
| gi->gl = glock_hash_next(gl); |
| gi->nhash++; |
| } else { |
| if (gi->hash >= GFS2_GL_HASH_SIZE) { |
| rcu_read_unlock(); |
| return 1; |
| } |
| gi->gl = glock_hash_chain(gi->hash); |
| gi->nhash = 0; |
| } |
| while (gi->gl == NULL) { |
| gi->hash++; |
| if (gi->hash >= GFS2_GL_HASH_SIZE) { |
| rcu_read_unlock(); |
| return 1; |
| } |
| gi->gl = glock_hash_chain(gi->hash); |
| gi->nhash = 0; |
| } |
| /* Skip entries for other sb and dead entries */ |
| } while (gi->sdp != gi->gl->gl_sbd || atomic_read(&gi->gl->gl_ref) == 0); |
| |
| return 0; |
| } |
| |
| static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct gfs2_glock_iter *gi = seq->private; |
| loff_t n = *pos; |
| |
| if (gi->last_pos <= *pos) |
| n = gi->nhash + (*pos - gi->last_pos); |
| else |
| gi->hash = 0; |
| |
| gi->nhash = 0; |
| rcu_read_lock(); |
| |
| do { |
| if (gfs2_glock_iter_next(gi)) |
| return NULL; |
| } while (n--); |
| |
| gi->last_pos = *pos; |
| return gi->gl; |
| } |
| |
| static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
| loff_t *pos) |
| { |
| struct gfs2_glock_iter *gi = seq->private; |
| |
| (*pos)++; |
| gi->last_pos = *pos; |
| if (gfs2_glock_iter_next(gi)) |
| return NULL; |
| |
| return gi->gl; |
| } |
| |
| static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
| { |
| struct gfs2_glock_iter *gi = seq->private; |
| |
| if (gi->gl) |
| rcu_read_unlock(); |
| gi->gl = NULL; |
| } |
| |
| static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
| { |
| return dump_glock(seq, iter_ptr); |
| } |
| |
| static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct gfs2_glock_iter *gi = seq->private; |
| |
| gi->hash = *pos; |
| if (*pos >= GFS2_NR_SBSTATS) |
| return NULL; |
| preempt_disable(); |
| return SEQ_START_TOKEN; |
| } |
| |
| static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr, |
| loff_t *pos) |
| { |
| struct gfs2_glock_iter *gi = seq->private; |
| (*pos)++; |
| gi->hash++; |
| if (gi->hash >= GFS2_NR_SBSTATS) { |
| preempt_enable(); |
| return NULL; |
| } |
| return SEQ_START_TOKEN; |
| } |
| |
| static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr) |
| { |
| preempt_enable(); |
| } |
| |
| static const struct seq_operations gfs2_glock_seq_ops = { |
| .start = gfs2_glock_seq_start, |
| .next = gfs2_glock_seq_next, |
| .stop = gfs2_glock_seq_stop, |
| .show = gfs2_glock_seq_show, |
| }; |
| |
| static const struct seq_operations gfs2_glstats_seq_ops = { |
| .start = gfs2_glock_seq_start, |
| .next = gfs2_glock_seq_next, |
| .stop = gfs2_glock_seq_stop, |
| .show = gfs2_glstats_seq_show, |
| }; |
| |
| static const struct seq_operations gfs2_sbstats_seq_ops = { |
| .start = gfs2_sbstats_seq_start, |
| .next = gfs2_sbstats_seq_next, |
| .stop = gfs2_sbstats_seq_stop, |
| .show = gfs2_sbstats_seq_show, |
| }; |
| |
| #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL) |
| |
| static int gfs2_glocks_open(struct inode *inode, struct file *file) |
| { |
| int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
| sizeof(struct gfs2_glock_iter)); |
| if (ret == 0) { |
| struct seq_file *seq = file->private_data; |
| struct gfs2_glock_iter *gi = seq->private; |
| gi->sdp = inode->i_private; |
| seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN); |
| if (seq->buf) |
| seq->size = GFS2_SEQ_GOODSIZE; |
| } |
| return ret; |
| } |
| |
| static int gfs2_glstats_open(struct inode *inode, struct file *file) |
| { |
| int ret = seq_open_private(file, &gfs2_glstats_seq_ops, |
| sizeof(struct gfs2_glock_iter)); |
| if (ret == 0) { |
| struct seq_file *seq = file->private_data; |
| struct gfs2_glock_iter *gi = seq->private; |
| gi->sdp = inode->i_private; |
| seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN); |
| if (seq->buf) |
| seq->size = GFS2_SEQ_GOODSIZE; |
| } |
| return ret; |
| } |
| |
| static int gfs2_sbstats_open(struct inode *inode, struct file *file) |
| { |
| int ret = seq_open_private(file, &gfs2_sbstats_seq_ops, |
| sizeof(struct gfs2_glock_iter)); |
| if (ret == 0) { |
| struct seq_file *seq = file->private_data; |
| struct gfs2_glock_iter *gi = seq->private; |
| gi->sdp = inode->i_private; |
| } |
| return ret; |
| } |
| |
| static const struct file_operations gfs2_glocks_fops = { |
| .owner = THIS_MODULE, |
| .open = gfs2_glocks_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_private, |
| }; |
| |
| static const struct file_operations gfs2_glstats_fops = { |
| .owner = THIS_MODULE, |
| .open = gfs2_glstats_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_private, |
| }; |
| |
| static const struct file_operations gfs2_sbstats_fops = { |
| .owner = THIS_MODULE, |
| .open = gfs2_sbstats_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_private, |
| }; |
| |
| int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) |
| { |
| sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
| if (!sdp->debugfs_dir) |
| return -ENOMEM; |
| sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", |
| S_IFREG | S_IRUGO, |
| sdp->debugfs_dir, sdp, |
| &gfs2_glocks_fops); |
| if (!sdp->debugfs_dentry_glocks) |
| goto fail; |
| |
| sdp->debugfs_dentry_glstats = debugfs_create_file("glstats", |
| S_IFREG | S_IRUGO, |
| sdp->debugfs_dir, sdp, |
| &gfs2_glstats_fops); |
| if (!sdp->debugfs_dentry_glstats) |
| goto fail; |
| |
| sdp->debugfs_dentry_sbstats = debugfs_create_file("sbstats", |
| S_IFREG | S_IRUGO, |
| sdp->debugfs_dir, sdp, |
| &gfs2_sbstats_fops); |
| if (!sdp->debugfs_dentry_sbstats) |
| goto fail; |
| |
| return 0; |
| fail: |
| gfs2_delete_debugfs_file(sdp); |
| return -ENOMEM; |
| } |
| |
| void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) |
| { |
| if (sdp->debugfs_dir) { |
| if (sdp->debugfs_dentry_glocks) { |
| debugfs_remove(sdp->debugfs_dentry_glocks); |
| sdp->debugfs_dentry_glocks = NULL; |
| } |
| if (sdp->debugfs_dentry_glstats) { |
| debugfs_remove(sdp->debugfs_dentry_glstats); |
| sdp->debugfs_dentry_glstats = NULL; |
| } |
| if (sdp->debugfs_dentry_sbstats) { |
| debugfs_remove(sdp->debugfs_dentry_sbstats); |
| sdp->debugfs_dentry_sbstats = NULL; |
| } |
| debugfs_remove(sdp->debugfs_dir); |
| sdp->debugfs_dir = NULL; |
| } |
| } |
| |
| int gfs2_register_debugfs(void) |
| { |
| gfs2_root = debugfs_create_dir("gfs2", NULL); |
| return gfs2_root ? 0 : -ENOMEM; |
| } |
| |
| void gfs2_unregister_debugfs(void) |
| { |
| debugfs_remove(gfs2_root); |
| gfs2_root = NULL; |
| } |