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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
- * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
- */
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
- #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/hash.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 <linux/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 <linux/lockref.h>
- #include <linux/rhashtable.h>
- #include <linux/pid_namespace.h>
- #include <linux/fdtable.h>
- #include <linux/file.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 {
- struct gfs2_sbd *sdp; /* incore superblock */
- struct rhashtable_iter hti; /* rhashtable iterator */
- 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 void __gfs2_glock_dq(struct gfs2_holder *gh);
- static void handle_callback(struct gfs2_glock *gl, unsigned int state,
- unsigned long delay, bool remote);
- 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 BIT(GFS2_GL_HASH_SHIFT)
- static const struct rhashtable_params ht_parms = {
- .nelem_hint = GFS2_GL_HASH_SIZE * 3 / 4,
- .key_len = offsetofend(struct lm_lockname, ln_type),
- .key_offset = offsetof(struct gfs2_glock, gl_name),
- .head_offset = offsetof(struct gfs2_glock, gl_node),
- };
- static struct rhashtable gl_hash_table;
- #define GLOCK_WAIT_TABLE_BITS 12
- #define GLOCK_WAIT_TABLE_SIZE (1 << GLOCK_WAIT_TABLE_BITS)
- static wait_queue_head_t glock_wait_table[GLOCK_WAIT_TABLE_SIZE] __cacheline_aligned;
- struct wait_glock_queue {
- struct lm_lockname *name;
- wait_queue_entry_t wait;
- };
- static int glock_wake_function(wait_queue_entry_t *wait, unsigned int mode,
- int sync, void *key)
- {
- struct wait_glock_queue *wait_glock =
- container_of(wait, struct wait_glock_queue, wait);
- struct lm_lockname *wait_name = wait_glock->name;
- struct lm_lockname *wake_name = key;
- if (wake_name->ln_sbd != wait_name->ln_sbd ||
- wake_name->ln_number != wait_name->ln_number ||
- wake_name->ln_type != wait_name->ln_type)
- return 0;
- return autoremove_wake_function(wait, mode, sync, key);
- }
- static wait_queue_head_t *glock_waitqueue(struct lm_lockname *name)
- {
- u32 hash = jhash2((u32 *)name, ht_parms.key_len / 4, 0);
- return glock_wait_table + hash_32(hash, GLOCK_WAIT_TABLE_BITS);
- }
- /**
- * wake_up_glock - Wake up waiters on a glock
- * @gl: the glock
- */
- static void wake_up_glock(struct gfs2_glock *gl)
- {
- wait_queue_head_t *wq = glock_waitqueue(&gl->gl_name);
- if (waitqueue_active(wq))
- __wake_up(wq, TASK_NORMAL, 1, &gl->gl_name);
- }
- static void gfs2_glock_dealloc(struct rcu_head *rcu)
- {
- struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
- kfree(gl->gl_lksb.sb_lvbptr);
- if (gl->gl_ops->go_flags & GLOF_ASPACE) {
- struct gfs2_glock_aspace *gla =
- container_of(gl, struct gfs2_glock_aspace, glock);
- kmem_cache_free(gfs2_glock_aspace_cachep, gla);
- } else
- kmem_cache_free(gfs2_glock_cachep, gl);
- }
- /**
- * glock_blocked_by_withdraw - determine if we can still use a glock
- * @gl: the glock
- *
- * We need to allow some glocks to be enqueued, dequeued, promoted, and demoted
- * when we're withdrawn. For example, to maintain metadata integrity, we should
- * disallow the use of inode and rgrp glocks when withdrawn. Other glocks, like
- * iopen or the transaction glocks may be safely used because none of their
- * metadata goes through the journal. So in general, we should disallow all
- * glocks that are journaled, and allow all the others. One exception is:
- * we need to allow our active journal to be promoted and demoted so others
- * may recover it and we can reacquire it when they're done.
- */
- static bool glock_blocked_by_withdraw(struct gfs2_glock *gl)
- {
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- if (likely(!gfs2_withdrawn(sdp)))
- return false;
- if (gl->gl_ops->go_flags & GLOF_NONDISK)
- return false;
- if (!sdp->sd_jdesc ||
- gl->gl_name.ln_number == sdp->sd_jdesc->jd_no_addr)
- return false;
- return true;
- }
- void gfs2_glock_free(struct gfs2_glock *gl)
- {
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- gfs2_glock_assert_withdraw(gl, atomic_read(&gl->gl_revokes) == 0);
- rhashtable_remove_fast(&gl_hash_table, &gl->gl_node, ht_parms);
- smp_mb();
- wake_up_glock(gl);
- 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, __lockref_is_dead(&gl->gl_lockref));
- lockref_get(&gl->gl_lockref);
- }
- /**
- * 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;
- /*
- * Note that demote_ok is used for the lru process of disposing of
- * glocks. For this purpose, we don't care if the glock's holders
- * have the HIF_MAY_DEMOTE flag set or not. If someone is using
- * them, don't demote.
- */
- 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)
- {
- if (!(gl->gl_ops->go_flags & GLOF_LRU))
- return;
- spin_lock(&lru_lock);
- list_move_tail(&gl->gl_lru, &lru_list);
- if (!test_bit(GLF_LRU, &gl->gl_flags)) {
- set_bit(GLF_LRU, &gl->gl_flags);
- atomic_inc(&lru_count);
- }
- spin_unlock(&lru_lock);
- }
- static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
- {
- if (!(gl->gl_ops->go_flags & GLOF_LRU))
- return;
- spin_lock(&lru_lock);
- if (test_bit(GLF_LRU, &gl->gl_flags)) {
- list_del_init(&gl->gl_lru);
- atomic_dec(&lru_count);
- clear_bit(GLF_LRU, &gl->gl_flags);
- }
- spin_unlock(&lru_lock);
- }
- /*
- * Enqueue the glock on the work queue. Passes one glock reference on to the
- * work queue.
- */
- static void __gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) {
- if (!queue_delayed_work(glock_workqueue, &gl->gl_work, delay)) {
- /*
- * We are holding the lockref spinlock, and the work was still
- * queued above. The queued work (glock_work_func) takes that
- * spinlock before dropping its glock reference(s), so it
- * cannot have dropped them in the meantime.
- */
- GLOCK_BUG_ON(gl, gl->gl_lockref.count < 2);
- gl->gl_lockref.count--;
- }
- }
- static void gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) {
- spin_lock(&gl->gl_lockref.lock);
- __gfs2_glock_queue_work(gl, delay);
- spin_unlock(&gl->gl_lockref.lock);
- }
- static void __gfs2_glock_put(struct gfs2_glock *gl)
- {
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- struct address_space *mapping = gfs2_glock2aspace(gl);
- lockref_mark_dead(&gl->gl_lockref);
- gfs2_glock_remove_from_lru(gl);
- spin_unlock(&gl->gl_lockref.lock);
- GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
- if (mapping) {
- truncate_inode_pages_final(mapping);
- if (!gfs2_withdrawn(sdp))
- GLOCK_BUG_ON(gl, !mapping_empty(mapping));
- }
- trace_gfs2_glock_put(gl);
- sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
- }
- /*
- * Cause the glock to be put in work queue context.
- */
- void gfs2_glock_queue_put(struct gfs2_glock *gl)
- {
- gfs2_glock_queue_work(gl, 0);
- }
- /**
- * gfs2_glock_put() - Decrement reference count on glock
- * @gl: The glock to put
- *
- */
- void gfs2_glock_put(struct gfs2_glock *gl)
- {
- if (lockref_put_or_lock(&gl->gl_lockref))
- return;
- __gfs2_glock_put(gl);
- }
- /**
- * may_grant - check if it's ok to grant a new lock
- * @gl: The glock
- * @current_gh: One of the current holders of @gl
- * @gh: The lock request which we wish to grant
- *
- * With our current compatibility rules, if a glock has one or more active
- * holders (HIF_HOLDER flag set), any of those holders can be passed in as
- * @current_gh; they are all the same as far as compatibility with the new @gh
- * goes.
- *
- * Returns true if it's ok to grant the lock.
- */
- static inline bool may_grant(struct gfs2_glock *gl,
- struct gfs2_holder *current_gh,
- struct gfs2_holder *gh)
- {
- if (current_gh) {
- GLOCK_BUG_ON(gl, !test_bit(HIF_HOLDER, ¤t_gh->gh_iflags));
- switch(current_gh->gh_state) {
- case LM_ST_EXCLUSIVE:
- /*
- * Here we make a special exception to grant holders
- * who agree to share the EX lock with other holders
- * who also have the bit set. If the original holder
- * has the LM_FLAG_NODE_SCOPE bit set, we grant more
- * holders with the bit set.
- */
- return gh->gh_state == LM_ST_EXCLUSIVE &&
- (current_gh->gh_flags & LM_FLAG_NODE_SCOPE) &&
- (gh->gh_flags & LM_FLAG_NODE_SCOPE);
- case LM_ST_SHARED:
- case LM_ST_DEFERRED:
- return gh->gh_state == current_gh->gh_state;
- default:
- return false;
- }
- }
- if (gl->gl_state == gh->gh_state)
- return true;
- if (gh->gh_flags & GL_EXACT)
- return false;
- if (gl->gl_state == LM_ST_EXCLUSIVE) {
- return gh->gh_state == LM_ST_SHARED ||
- gh->gh_state == LM_ST_DEFERRED;
- }
- if (gh->gh_flags & LM_FLAG_ANY)
- return gl->gl_state != LM_ST_UNLOCKED;
- return false;
- }
- static void gfs2_holder_wake(struct gfs2_holder *gh)
- {
- clear_bit(HIF_WAIT, &gh->gh_iflags);
- smp_mb__after_atomic();
- wake_up_bit(&gh->gh_iflags, HIF_WAIT);
- if (gh->gh_flags & GL_ASYNC) {
- struct gfs2_sbd *sdp = gh->gh_gl->gl_name.ln_sbd;
- wake_up(&sdp->sd_async_glock_wait);
- }
- }
- /**
- * do_error - Something unexpected has happened during a lock request
- * @gl: The glock
- * @ret: The status from the DLM
- */
- static 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_WAIT, &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);
- }
- }
- /**
- * demote_incompat_holders - demote incompatible demoteable holders
- * @gl: the glock we want to promote
- * @current_gh: the newly promoted holder
- *
- * We're passing the newly promoted holder in @current_gh, but actually, any of
- * the strong holders would do.
- */
- static void demote_incompat_holders(struct gfs2_glock *gl,
- struct gfs2_holder *current_gh)
- {
- struct gfs2_holder *gh, *tmp;
- /*
- * Demote incompatible holders before we make ourselves eligible.
- * (This holder may or may not allow auto-demoting, but we don't want
- * to demote the new holder before it's even granted.)
- */
- list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
- /*
- * Since holders are at the front of the list, we stop when we
- * find the first non-holder.
- */
- if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
- return;
- if (gh == current_gh)
- continue;
- if (test_bit(HIF_MAY_DEMOTE, &gh->gh_iflags) &&
- !may_grant(gl, current_gh, gh)) {
- /*
- * We should not recurse into do_promote because
- * __gfs2_glock_dq only calls handle_callback,
- * gfs2_glock_add_to_lru and __gfs2_glock_queue_work.
- */
- __gfs2_glock_dq(gh);
- }
- }
- }
- /**
- * 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_first_entry(&gl->gl_holders, struct gfs2_holder,
- gh_list);
- if (test_bit(HIF_HOLDER, &gh->gh_iflags))
- return gh;
- }
- return NULL;
- }
- /**
- * find_first_strong_holder - find the first non-demoteable holder
- * @gl: the glock
- *
- * Find the first holder that doesn't have the HIF_MAY_DEMOTE flag set.
- */
- static inline struct gfs2_holder *
- find_first_strong_holder(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 NULL;
- if (!test_bit(HIF_MAY_DEMOTE, &gh->gh_iflags))
- return gh;
- }
- return NULL;
- }
- /*
- * gfs2_instantiate - Call the glops instantiate function
- * @gh: The glock holder
- *
- * Returns: 0 if instantiate was successful, or error.
- */
- int gfs2_instantiate(struct gfs2_holder *gh)
- {
- struct gfs2_glock *gl = gh->gh_gl;
- const struct gfs2_glock_operations *glops = gl->gl_ops;
- int ret;
- again:
- if (!test_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags))
- goto done;
- /*
- * Since we unlock the lockref lock, we set a flag to indicate
- * instantiate is in progress.
- */
- if (test_and_set_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags)) {
- wait_on_bit(&gl->gl_flags, GLF_INSTANTIATE_IN_PROG,
- TASK_UNINTERRUPTIBLE);
- /*
- * Here we just waited for a different instantiate to finish.
- * But that may not have been successful, as when a process
- * locks an inode glock _before_ it has an actual inode to
- * instantiate into. So we check again. This process might
- * have an inode to instantiate, so might be successful.
- */
- goto again;
- }
- ret = glops->go_instantiate(gl);
- if (!ret)
- clear_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags);
- clear_and_wake_up_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags);
- if (ret)
- return ret;
- done:
- if (glops->go_held)
- return glops->go_held(gh);
- return 0;
- }
- /**
- * 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
- */
- static int do_promote(struct gfs2_glock *gl)
- {
- struct gfs2_holder *gh, *current_gh;
- bool incompat_holders_demoted = false;
- current_gh = find_first_strong_holder(gl);
- list_for_each_entry(gh, &gl->gl_holders, gh_list) {
- if (test_bit(HIF_HOLDER, &gh->gh_iflags))
- continue;
- if (!may_grant(gl, current_gh, gh)) {
- /*
- * If we get here, it means we may not grant this
- * holder for some reason. If this holder is at the
- * head of the list, it means we have a blocked holder
- * at the head, so return 1.
- */
- if (list_is_first(&gh->gh_list, &gl->gl_holders))
- return 1;
- do_error(gl, 0);
- break;
- }
- set_bit(HIF_HOLDER, &gh->gh_iflags);
- trace_gfs2_promote(gh);
- gfs2_holder_wake(gh);
- if (!incompat_holders_demoted) {
- current_gh = gh;
- demote_incompat_holders(gl, current_gh);
- incompat_holders_demoted = true;
- }
- }
- 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) {
- GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
- if (held2)
- gl->gl_lockref.count++;
- else
- gl->gl_lockref.count--;
- }
- 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_set_demote(struct gfs2_glock *gl)
- {
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- set_bit(GLF_DEMOTE, &gl->gl_flags);
- smp_mb();
- wake_up(&sdp->sd_async_glock_wait);
- }
- 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_atomic();
- 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;
- spin_lock(&gl->gl_lockref.lock);
- 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 && (ret & LM_OUT_CANCELED))
- gfs2_holder_wake(gh);
- 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 */
- fs_err(gl->gl_name.ln_sbd, "wanted %u got %u\n",
- gl->gl_target, state);
- GLOCK_BUG_ON(gl, 1);
- }
- spin_unlock(&gl->gl_lockref.lock);
- 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) {
- int rv;
- spin_unlock(&gl->gl_lockref.lock);
- rv = glops->go_xmote_bh(gl);
- spin_lock(&gl->gl_lockref.lock);
- if (rv) {
- do_error(gl, rv);
- goto out;
- }
- }
- do_promote(gl);
- }
- out:
- clear_bit(GLF_LOCK, &gl->gl_flags);
- spin_unlock(&gl->gl_lockref.lock);
- }
- static bool is_system_glock(struct gfs2_glock *gl)
- {
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
- if (gl == m_ip->i_gl)
- return true;
- return false;
- }
- /**
- * 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_lockref.lock)
- __acquires(&gl->gl_lockref.lock)
- {
- const struct gfs2_glock_operations *glops = gl->gl_ops;
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- unsigned int lck_flags = (unsigned int)(gh ? gh->gh_flags : 0);
- int ret;
- if (target != LM_ST_UNLOCKED && glock_blocked_by_withdraw(gl) &&
- gh && !(gh->gh_flags & LM_FLAG_NOEXP))
- goto skip_inval;
- 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) {
- /*
- * If another process is already doing the invalidate, let that
- * finish first. The glock state machine will get back to this
- * holder again later.
- */
- if (test_and_set_bit(GLF_INVALIDATE_IN_PROGRESS,
- &gl->gl_flags))
- return;
- 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_lockref.lock);
- if (glops->go_sync) {
- ret = glops->go_sync(gl);
- /* If we had a problem syncing (due to io errors or whatever,
- * we should not invalidate the metadata or tell dlm to
- * release the glock to other nodes.
- */
- if (ret) {
- if (cmpxchg(&sdp->sd_log_error, 0, ret)) {
- fs_err(sdp, "Error %d syncing glock \n", ret);
- gfs2_dump_glock(NULL, gl, true);
- }
- goto skip_inval;
- }
- }
- if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) {
- /*
- * The call to go_sync should have cleared out the ail list.
- * If there are still items, we have a problem. We ought to
- * withdraw, but we can't because the withdraw code also uses
- * glocks. Warn about the error, dump the glock, then fall
- * through and wait for logd to do the withdraw for us.
- */
- if ((atomic_read(&gl->gl_ail_count) != 0) &&
- (!cmpxchg(&sdp->sd_log_error, 0, -EIO))) {
- gfs2_glock_assert_warn(gl,
- !atomic_read(&gl->gl_ail_count));
- gfs2_dump_glock(NULL, gl, true);
- }
- glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
- clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
- }
- skip_inval:
- gfs2_glock_hold(gl);
- /*
- * Check for an error encountered since we called go_sync and go_inval.
- * If so, we can't withdraw from the glock code because the withdraw
- * code itself uses glocks (see function signal_our_withdraw) to
- * change the mount to read-only. Most importantly, we must not call
- * dlm to unlock the glock until the journal is in a known good state
- * (after journal replay) otherwise other nodes may use the object
- * (rgrp or dinode) and then later, journal replay will corrupt the
- * file system. The best we can do here is wait for the logd daemon
- * to see sd_log_error and withdraw, and in the meantime, requeue the
- * work for later.
- *
- * We make a special exception for some system glocks, such as the
- * system statfs inode glock, which needs to be granted before the
- * gfs2_quotad daemon can exit, and that exit needs to finish before
- * we can unmount the withdrawn file system.
- *
- * However, if we're just unlocking the lock (say, for unmount, when
- * gfs2_gl_hash_clear calls clear_glock) and recovery is complete
- * then it's okay to tell dlm to unlock it.
- */
- if (unlikely(sdp->sd_log_error && !gfs2_withdrawn(sdp)))
- gfs2_withdraw_delayed(sdp);
- if (glock_blocked_by_withdraw(gl) &&
- (target != LM_ST_UNLOCKED ||
- test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags))) {
- if (!is_system_glock(gl)) {
- handle_callback(gl, LM_ST_UNLOCKED, 0, false); /* sets demote */
- /*
- * Ordinarily, we would call dlm and its callback would call
- * finish_xmote, which would call state_change() to the new state.
- * Since we withdrew, we won't call dlm, so call state_change
- * manually, but to the UNLOCKED state we desire.
- */
- state_change(gl, LM_ST_UNLOCKED);
- /*
- * We skip telling dlm to do the locking, so we won't get a
- * reply that would otherwise clear GLF_LOCK. So we clear it here.
- */
- clear_bit(GLF_LOCK, &gl->gl_flags);
- clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
- gfs2_glock_queue_work(gl, GL_GLOCK_DFT_HOLD);
- goto out;
- } else {
- clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
- }
- }
- if (sdp->sd_lockstruct.ls_ops->lm_lock) {
- /* lock_dlm */
- ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
- if (ret == -EINVAL && gl->gl_target == LM_ST_UNLOCKED &&
- target == LM_ST_UNLOCKED &&
- test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags)) {
- finish_xmote(gl, target);
- gfs2_glock_queue_work(gl, 0);
- } else if (ret) {
- fs_err(sdp, "lm_lock ret %d\n", ret);
- GLOCK_BUG_ON(gl, !gfs2_withdrawn(sdp));
- }
- } else { /* lock_nolock */
- finish_xmote(gl, target);
- gfs2_glock_queue_work(gl, 0);
- }
- out:
- spin_lock(&gl->gl_lockref.lock);
- }
- /**
- * 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_lockref.lock)
- __acquires(&gl->gl_lockref.lock)
- {
- struct gfs2_holder *gh = NULL;
- 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);
- if (do_promote(gl) == 0)
- goto out_unlock;
- 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);
- return;
- out_sched:
- clear_bit(GLF_LOCK, &gl->gl_flags);
- smp_mb__after_atomic();
- gl->gl_lockref.count++;
- __gfs2_glock_queue_work(gl, 0);
- return;
- out_unlock:
- clear_bit(GLF_LOCK, &gl->gl_flags);
- smp_mb__after_atomic();
- return;
- }
- void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation)
- {
- struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr;
- if (ri->ri_magic == 0)
- ri->ri_magic = cpu_to_be32(GFS2_MAGIC);
- if (ri->ri_magic == cpu_to_be32(GFS2_MAGIC))
- ri->ri_generation_deleted = cpu_to_be64(generation);
- }
- bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation)
- {
- struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr;
- if (ri->ri_magic != cpu_to_be32(GFS2_MAGIC))
- return false;
- return generation <= be64_to_cpu(ri->ri_generation_deleted);
- }
- static void gfs2_glock_poke(struct gfs2_glock *gl)
- {
- int flags = LM_FLAG_TRY_1CB | LM_FLAG_ANY | GL_SKIP;
- struct gfs2_holder gh;
- int error;
- __gfs2_holder_init(gl, LM_ST_SHARED, flags, &gh, _RET_IP_);
- error = gfs2_glock_nq(&gh);
- if (!error)
- gfs2_glock_dq(&gh);
- gfs2_holder_uninit(&gh);
- }
- static bool gfs2_try_evict(struct gfs2_glock *gl)
- {
- struct gfs2_inode *ip;
- bool evicted = false;
- /*
- * If there is contention on the iopen glock and we have an inode, try
- * to grab and release the inode so that it can be evicted. This will
- * allow the remote node to go ahead and delete the inode without us
- * having to do it, which will avoid rgrp glock thrashing.
- *
- * The remote node is likely still holding the corresponding inode
- * glock, so it will run before we get to verify that the delete has
- * happened below.
- */
- spin_lock(&gl->gl_lockref.lock);
- ip = gl->gl_object;
- if (ip && !igrab(&ip->i_inode))
- ip = NULL;
- spin_unlock(&gl->gl_lockref.lock);
- if (ip) {
- struct gfs2_glock *inode_gl = NULL;
- gl->gl_no_formal_ino = ip->i_no_formal_ino;
- set_bit(GIF_DEFERRED_DELETE, &ip->i_flags);
- d_prune_aliases(&ip->i_inode);
- iput(&ip->i_inode);
- /* If the inode was evicted, gl->gl_object will now be NULL. */
- spin_lock(&gl->gl_lockref.lock);
- ip = gl->gl_object;
- if (ip) {
- inode_gl = ip->i_gl;
- lockref_get(&inode_gl->gl_lockref);
- clear_bit(GIF_DEFERRED_DELETE, &ip->i_flags);
- }
- spin_unlock(&gl->gl_lockref.lock);
- if (inode_gl) {
- gfs2_glock_poke(inode_gl);
- gfs2_glock_put(inode_gl);
- }
- evicted = !ip;
- }
- return evicted;
- }
- static void delete_work_func(struct work_struct *work)
- {
- struct delayed_work *dwork = to_delayed_work(work);
- struct gfs2_glock *gl = container_of(dwork, struct gfs2_glock, gl_delete);
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- struct inode *inode;
- u64 no_addr = gl->gl_name.ln_number;
- spin_lock(&gl->gl_lockref.lock);
- clear_bit(GLF_PENDING_DELETE, &gl->gl_flags);
- spin_unlock(&gl->gl_lockref.lock);
- if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
- /*
- * If we can evict the inode, give the remote node trying to
- * delete the inode some time before verifying that the delete
- * has happened. Otherwise, if we cause contention on the inode glock
- * immediately, the remote node will think that we still have
- * the inode in use, and so it will give up waiting.
- *
- * If we can't evict the inode, signal to the remote node that
- * the inode is still in use. We'll later try to delete the
- * inode locally in gfs2_evict_inode.
- *
- * FIXME: We only need to verify that the remote node has
- * deleted the inode because nodes before this remote delete
- * rework won't cooperate. At a later time, when we no longer
- * care about compatibility with such nodes, we can skip this
- * step entirely.
- */
- if (gfs2_try_evict(gl)) {
- if (gfs2_queue_delete_work(gl, 5 * HZ))
- return;
- }
- goto out;
- }
- inode = gfs2_lookup_by_inum(sdp, no_addr, gl->gl_no_formal_ino,
- GFS2_BLKST_UNLINKED);
- if (IS_ERR(inode)) {
- if (PTR_ERR(inode) == -EAGAIN &&
- (gfs2_queue_delete_work(gl, 5 * HZ)))
- return;
- } else {
- d_prune_aliases(inode);
- iput(inode);
- }
- out:
- 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);
- unsigned int drop_refs = 1;
- if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
- finish_xmote(gl, gl->gl_reply);
- drop_refs++;
- }
- spin_lock(&gl->gl_lockref.lock);
- 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);
- gfs2_set_demote(gl);
- }
- }
- run_queue(gl, 0);
- if (delay) {
- /* Keep one glock reference for the work we requeue. */
- drop_refs--;
- if (gl->gl_name.ln_type != LM_TYPE_INODE)
- delay = 0;
- __gfs2_glock_queue_work(gl, delay);
- }
- /*
- * Drop the remaining glock references manually here. (Mind that
- * __gfs2_glock_queue_work depends on the lockref spinlock begin held
- * here as well.)
- */
- gl->gl_lockref.count -= drop_refs;
- if (!gl->gl_lockref.count) {
- __gfs2_glock_put(gl);
- return;
- }
- spin_unlock(&gl->gl_lockref.lock);
- }
- static struct gfs2_glock *find_insert_glock(struct lm_lockname *name,
- struct gfs2_glock *new)
- {
- struct wait_glock_queue wait;
- wait_queue_head_t *wq = glock_waitqueue(name);
- struct gfs2_glock *gl;
- wait.name = name;
- init_wait(&wait.wait);
- wait.wait.func = glock_wake_function;
- again:
- prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
- rcu_read_lock();
- if (new) {
- gl = rhashtable_lookup_get_insert_fast(&gl_hash_table,
- &new->gl_node, ht_parms);
- if (IS_ERR(gl))
- goto out;
- } else {
- gl = rhashtable_lookup_fast(&gl_hash_table,
- name, ht_parms);
- }
- if (gl && !lockref_get_not_dead(&gl->gl_lockref)) {
- rcu_read_unlock();
- schedule();
- goto again;
- }
- out:
- rcu_read_unlock();
- finish_wait(wq, &wait.wait);
- return 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,
- .ln_sbd = sdp };
- struct gfs2_glock *gl, *tmp;
- struct address_space *mapping;
- int ret = 0;
- gl = find_insert_glock(&name, NULL);
- if (gl) {
- *glp = gl;
- return 0;
- }
- if (!create)
- return -ENOENT;
- if (glops->go_flags & GLOF_ASPACE) {
- struct gfs2_glock_aspace *gla =
- kmem_cache_alloc(gfs2_glock_aspace_cachep, GFP_NOFS);
- if (!gla)
- return -ENOMEM;
- gl = &gla->glock;
- } else {
- gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_NOFS);
- if (!gl)
- return -ENOMEM;
- }
- memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
- gl->gl_ops = glops;
- if (glops->go_flags & GLOF_LVB) {
- gl->gl_lksb.sb_lvbptr = kzalloc(GDLM_LVB_SIZE, GFP_NOFS);
- if (!gl->gl_lksb.sb_lvbptr) {
- gfs2_glock_dealloc(&gl->gl_rcu);
- return -ENOMEM;
- }
- }
- atomic_inc(&sdp->sd_glock_disposal);
- gl->gl_node.next = NULL;
- gl->gl_flags = glops->go_instantiate ? BIT(GLF_INSTANTIATE_NEEDED) : 0;
- gl->gl_name = name;
- lockdep_set_subclass(&gl->gl_lockref.lock, glops->go_subclass);
- gl->gl_lockref.count = 1;
- gl->gl_state = LM_ST_UNLOCKED;
- gl->gl_target = LM_ST_UNLOCKED;
- gl->gl_demote_state = LM_ST_EXCLUSIVE;
- gl->gl_dstamp = 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);
- if (gl->gl_name.ln_type == LM_TYPE_IOPEN)
- INIT_DELAYED_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->writeback_index = 0;
- }
- tmp = find_insert_glock(&name, gl);
- if (!tmp) {
- *glp = gl;
- goto out;
- }
- if (IS_ERR(tmp)) {
- ret = PTR_ERR(tmp);
- goto out_free;
- }
- *glp = tmp;
- out_free:
- gfs2_glock_dealloc(&gl->gl_rcu);
- if (atomic_dec_and_test(&sdp->sd_glock_disposal))
- wake_up(&sdp->sd_glock_wait);
- out:
- return ret;
- }
- /**
- * __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, u16 flags,
- struct gfs2_holder *gh, unsigned long ip)
- {
- INIT_LIST_HEAD(&gh->gh_list);
- gh->gh_gl = gl;
- gh->gh_ip = ip;
- gh->gh_owner_pid = get_pid(task_pid(current));
- gh->gh_state = state;
- gh->gh_flags = flags;
- 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, u16 flags, struct gfs2_holder *gh)
- {
- gh->gh_state = state;
- gh->gh_flags = flags;
- gh->gh_iflags = 0;
- gh->gh_ip = _RET_IP_;
- 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);
- gfs2_holder_mark_uninitialized(gh);
- gh->gh_ip = 0;
- }
- static void gfs2_glock_update_hold_time(struct gfs2_glock *gl,
- unsigned long start_time)
- {
- /* Have we waited longer that a second? */
- if (time_after(jiffies, start_time + HZ)) {
- /* Lengthen the minimum hold time. */
- gl->gl_hold_time = min(gl->gl_hold_time + GL_GLOCK_HOLD_INCR,
- GL_GLOCK_MAX_HOLD);
- }
- }
- /**
- * gfs2_glock_holder_ready - holder is ready and its error code can be collected
- * @gh: the glock holder
- *
- * Called when a glock holder no longer needs to be waited for because it is
- * now either held (HIF_HOLDER set; gh_error == 0), or acquiring the lock has
- * failed (gh_error != 0).
- */
- int gfs2_glock_holder_ready(struct gfs2_holder *gh)
- {
- if (gh->gh_error || (gh->gh_flags & GL_SKIP))
- return gh->gh_error;
- gh->gh_error = gfs2_instantiate(gh);
- if (gh->gh_error)
- gfs2_glock_dq(gh);
- return gh->gh_error;
- }
- /**
- * 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 start_time = jiffies;
- might_sleep();
- wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
- gfs2_glock_update_hold_time(gh->gh_gl, start_time);
- return gfs2_glock_holder_ready(gh);
- }
- static int glocks_pending(unsigned int num_gh, struct gfs2_holder *ghs)
- {
- int i;
- for (i = 0; i < num_gh; i++)
- if (test_bit(HIF_WAIT, &ghs[i].gh_iflags))
- return 1;
- return 0;
- }
- /**
- * gfs2_glock_async_wait - wait on multiple asynchronous glock acquisitions
- * @num_gh: the number of holders in the array
- * @ghs: the glock holder array
- *
- * Returns: 0 on success, meaning all glocks have been granted and are held.
- * -ESTALE if the request timed out, meaning all glocks were released,
- * and the caller should retry the operation.
- */
- int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs)
- {
- struct gfs2_sbd *sdp = ghs[0].gh_gl->gl_name.ln_sbd;
- int i, ret = 0, timeout = 0;
- unsigned long start_time = jiffies;
- might_sleep();
- /*
- * Total up the (minimum hold time * 2) of all glocks and use that to
- * determine the max amount of time we should wait.
- */
- for (i = 0; i < num_gh; i++)
- timeout += ghs[i].gh_gl->gl_hold_time << 1;
- if (!wait_event_timeout(sdp->sd_async_glock_wait,
- !glocks_pending(num_gh, ghs), timeout)) {
- ret = -ESTALE; /* request timed out. */
- goto out;
- }
- for (i = 0; i < num_gh; i++) {
- struct gfs2_holder *gh = &ghs[i];
- int ret2;
- if (test_bit(HIF_HOLDER, &gh->gh_iflags)) {
- gfs2_glock_update_hold_time(gh->gh_gl,
- start_time);
- }
- ret2 = gfs2_glock_holder_ready(gh);
- if (!ret)
- ret = ret2;
- }
- out:
- if (ret) {
- for (i = 0; i < num_gh; i++) {
- struct gfs2_holder *gh = &ghs[i];
- gfs2_glock_dq(gh);
- }
- }
- return ret;
- }
- /**
- * handle_callback - process a demote request
- * @gl: the glock
- * @state: the state the caller wants us to change to
- * @delay: zero to demote immediately; otherwise pending demote
- * @remote: true if this came from a different cluster node
- *
- * 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)
- {
- if (delay)
- set_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
- else
- gfs2_set_demote(gl);
- 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;
- pr_err("%pV", &vaf);
- }
- va_end(args);
- }
- static inline bool pid_is_meaningful(const struct gfs2_holder *gh)
- {
- if (!(gh->gh_flags & GL_NOPID))
- return true;
- if (gh->gh_state == LM_ST_UNLOCKED)
- return true;
- return false;
- }
- /**
- * 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_lockref.lock)
- __acquires(&gl->gl_lockref.lock)
- {
- struct gfs2_glock *gl = gh->gh_gl;
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- struct list_head *insert_pt = NULL;
- struct gfs2_holder *gh2;
- int try_futile = 0;
- GLOCK_BUG_ON(gl, gh->gh_owner_pid == NULL);
- if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
- GLOCK_BUG_ON(gl, true);
- if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
- if (test_bit(GLF_LOCK, &gl->gl_flags)) {
- struct gfs2_holder *current_gh;
- current_gh = find_first_strong_holder(gl);
- try_futile = !may_grant(gl, current_gh, gh);
- }
- if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
- goto fail;
- }
- list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
- if (likely(gh2->gh_owner_pid != gh->gh_owner_pid))
- continue;
- if (gh->gh_gl->gl_ops->go_type == LM_TYPE_FLOCK)
- continue;
- if (test_bit(HIF_MAY_DEMOTE, &gh2->gh_iflags))
- continue;
- if (!pid_is_meaningful(gh2))
- continue;
- goto trap_recursive;
- }
- list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
- 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;
- }
- 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_first_entry(&gl->gl_holders, struct gfs2_holder, gh_list);
- if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
- spin_unlock(&gl->gl_lockref.lock);
- if (sdp->sd_lockstruct.ls_ops->lm_cancel)
- sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
- spin_lock(&gl->gl_lockref.lock);
- }
- return;
- trap_recursive:
- fs_err(sdp, "original: %pSR\n", (void *)gh2->gh_ip);
- fs_err(sdp, "pid: %d\n", pid_nr(gh2->gh_owner_pid));
- fs_err(sdp, "lock type: %d req lock state : %d\n",
- gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
- fs_err(sdp, "new: %pSR\n", (void *)gh->gh_ip);
- fs_err(sdp, "pid: %d\n", pid_nr(gh->gh_owner_pid));
- fs_err(sdp, "lock type: %d req lock state : %d\n",
- gh->gh_gl->gl_name.ln_type, gh->gh_state);
- gfs2_dump_glock(NULL, gl, true);
- 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;
- int error = 0;
- if (glock_blocked_by_withdraw(gl) && !(gh->gh_flags & LM_FLAG_NOEXP))
- return -EIO;
- if (test_bit(GLF_LRU, &gl->gl_flags))
- gfs2_glock_remove_from_lru(gl);
- gh->gh_error = 0;
- spin_lock(&gl->gl_lockref.lock);
- add_to_queue(gh);
- if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&
- test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
- set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
- gl->gl_lockref.count++;
- __gfs2_glock_queue_work(gl, 0);
- }
- run_queue(gl, 1);
- spin_unlock(&gl->gl_lockref.lock);
- 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;
- }
- static inline bool needs_demote(struct gfs2_glock *gl)
- {
- return (test_bit(GLF_DEMOTE, &gl->gl_flags) ||
- test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags));
- }
- static void __gfs2_glock_dq(struct gfs2_holder *gh)
- {
- struct gfs2_glock *gl = gh->gh_gl;
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- unsigned delay = 0;
- int fast_path = 0;
- /*
- * This while loop is similar to function demote_incompat_holders:
- * If the glock is due to be demoted (which may be from another node
- * or even if this holder is GL_NOCACHE), the weak holders are
- * demoted as well, allowing the glock to be demoted.
- */
- while (gh) {
- /*
- * If we're in the process of file system withdraw, we cannot
- * just dequeue any glocks until our journal is recovered, lest
- * we introduce file system corruption. We need two exceptions
- * to this rule: We need to allow unlocking of nondisk glocks
- * and the glock for our own journal that needs recovery.
- */
- if (test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags) &&
- glock_blocked_by_withdraw(gl) &&
- gh->gh_gl != sdp->sd_jinode_gl) {
- sdp->sd_glock_dqs_held++;
- spin_unlock(&gl->gl_lockref.lock);
- might_sleep();
- wait_on_bit(&sdp->sd_flags, SDF_WITHDRAW_RECOVERY,
- TASK_UNINTERRUPTIBLE);
- spin_lock(&gl->gl_lockref.lock);
- }
- /*
- * This holder should not be cached, so mark it for demote.
- * Note: this should be done before the check for needs_demote
- * below.
- */
- if (gh->gh_flags & GL_NOCACHE)
- handle_callback(gl, LM_ST_UNLOCKED, 0, false);
- list_del_init(&gh->gh_list);
- clear_bit(HIF_HOLDER, &gh->gh_iflags);
- trace_gfs2_glock_queue(gh, 0);
- /*
- * If there hasn't been a demote request we are done.
- * (Let the remaining holders, if any, keep holding it.)
- */
- if (!needs_demote(gl)) {
- if (list_empty(&gl->gl_holders))
- fast_path = 1;
- break;
- }
- /*
- * If we have another strong holder (we cannot auto-demote)
- * we are done. It keeps holding it until it is done.
- */
- if (find_first_strong_holder(gl))
- break;
- /*
- * If we have a weak holder at the head of the list, it
- * (and all others like it) must be auto-demoted. If there
- * are no more weak holders, we exit the while loop.
- */
- gh = find_first_holder(gl);
- }
- if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl))
- gfs2_glock_add_to_lru(gl);
- if (unlikely(!fast_path)) {
- gl->gl_lockref.count++;
- 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;
- __gfs2_glock_queue_work(gl, delay);
- }
- }
- /**
- * 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;
- spin_lock(&gl->gl_lockref.lock);
- if (list_is_first(&gh->gh_list, &gl->gl_holders) &&
- !test_bit(HIF_HOLDER, &gh->gh_iflags)) {
- spin_unlock(&gl->gl_lockref.lock);
- gl->gl_name.ln_sbd->sd_lockstruct.ls_ops->lm_cancel(gl);
- wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
- spin_lock(&gl->gl_lockref.lock);
- }
- __gfs2_glock_dq(gh);
- spin_unlock(&gl->gl_lockref.lock);
- }
- 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, 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, u16 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 - synchronously acquire more than one glock in deadlock free order
- * @num_gh: the number of structures
- * @ghs: an array of struct gfs2_holder structures
- * @p: placeholder for the holder structure to pass back
- *
- * 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++) {
- 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:
- return gfs2_glock_nq(ghs);
- default:
- if (num_gh <= 4)
- break;
- pph = kmalloc_array(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);
- spin_lock(&gl->gl_lockref.lock);
- holdtime = gl->gl_tchange + gl->gl_hold_time;
- if (!list_empty(&gl->gl_holders) &&
- 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;
- }
- /*
- * Note 1: We cannot call demote_incompat_holders from handle_callback
- * or gfs2_set_demote due to recursion problems like: gfs2_glock_dq ->
- * handle_callback -> demote_incompat_holders -> gfs2_glock_dq
- * Plus, we only want to demote the holders if the request comes from
- * a remote cluster node because local holder conflicts are resolved
- * elsewhere.
- *
- * Note 2: if a remote node wants this glock in EX mode, lock_dlm will
- * request that we set our state to UNLOCKED. Here we mock up a holder
- * to make it look like someone wants the lock EX locally. Any SH
- * and DF requests should be able to share the lock without demoting.
- *
- * Note 3: We only want to demote the demoteable holders when there
- * are no more strong holders. The demoteable holders might as well
- * keep the glock until the last strong holder is done with it.
- */
- if (!find_first_strong_holder(gl)) {
- struct gfs2_holder mock_gh = {
- .gh_gl = gl,
- .gh_state = (state == LM_ST_UNLOCKED) ?
- LM_ST_EXCLUSIVE : state,
- .gh_iflags = BIT(HIF_HOLDER)
- };
- demote_incompat_holders(gl, &mock_gh);
- }
- handle_callback(gl, state, delay, true);
- __gfs2_glock_queue_work(gl, delay);
- spin_unlock(&gl->gl_lockref.lock);
- }
- /**
- * 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_lockref.lock 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_name.ln_sbd->sd_lockstruct;
- spin_lock(&gl->gl_lockref.lock);
- 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_lockref.lock);
- return;
- }
- }
- gl->gl_lockref.count++;
- set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
- __gfs2_glock_queue_work(gl, 0);
- spin_unlock(&gl->gl_lockref.lock);
- }
- static int glock_cmp(void *priv, const struct list_head *a,
- const 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_first_entry(list, struct gfs2_glock, gl_lru);
- list_del_init(&gl->gl_lru);
- clear_bit(GLF_LRU, &gl->gl_flags);
- if (!spin_trylock(&gl->gl_lockref.lock)) {
- add_back_to_lru:
- list_add(&gl->gl_lru, &lru_list);
- set_bit(GLF_LRU, &gl->gl_flags);
- atomic_inc(&lru_count);
- continue;
- }
- if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
- spin_unlock(&gl->gl_lockref.lock);
- goto add_back_to_lru;
- }
- gl->gl_lockref.count++;
- if (demote_ok(gl))
- handle_callback(gl, LM_ST_UNLOCKED, 0, false);
- WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
- __gfs2_glock_queue_work(gl, 0);
- spin_unlock(&gl->gl_lockref.lock);
- cond_resched_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 long gfs2_scan_glock_lru(int nr)
- {
- struct gfs2_glock *gl;
- LIST_HEAD(skipped);
- LIST_HEAD(dispose);
- long freed = 0;
- spin_lock(&lru_lock);
- while ((nr-- >= 0) && !list_empty(&lru_list)) {
- gl = list_first_entry(&lru_list, struct gfs2_glock, gl_lru);
- /* Test for being demotable */
- if (!test_bit(GLF_LOCK, &gl->gl_flags)) {
- list_move(&gl->gl_lru, &dispose);
- atomic_dec(&lru_count);
- freed++;
- 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);
- return freed;
- }
- static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink,
- struct shrink_control *sc)
- {
- if (!(sc->gfp_mask & __GFP_FS))
- return SHRINK_STOP;
- return gfs2_scan_glock_lru(sc->nr_to_scan);
- }
- static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink,
- struct shrink_control *sc)
- {
- return vfs_pressure_ratio(atomic_read(&lru_count));
- }
- static struct shrinker glock_shrinker = {
- .seeks = DEFAULT_SEEKS,
- .count_objects = gfs2_glock_shrink_count,
- .scan_objects = gfs2_glock_shrink_scan,
- };
- /**
- * glock_hash_walk - Call a function for glock in a hash bucket
- * @examiner: the function
- * @sdp: the filesystem
- *
- * Note that the function can be called multiple times on the same
- * object. So the user must ensure that the function can cope with
- * that.
- */
- static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
- {
- struct gfs2_glock *gl;
- struct rhashtable_iter iter;
- rhashtable_walk_enter(&gl_hash_table, &iter);
- do {
- rhashtable_walk_start(&iter);
- while ((gl = rhashtable_walk_next(&iter)) && !IS_ERR(gl)) {
- if (gl->gl_name.ln_sbd == sdp)
- examiner(gl);
- }
- rhashtable_walk_stop(&iter);
- } while (cond_resched(), gl == ERR_PTR(-EAGAIN));
- rhashtable_walk_exit(&iter);
- }
- bool gfs2_queue_delete_work(struct gfs2_glock *gl, unsigned long delay)
- {
- bool queued;
- spin_lock(&gl->gl_lockref.lock);
- queued = queue_delayed_work(gfs2_delete_workqueue,
- &gl->gl_delete, delay);
- if (queued)
- set_bit(GLF_PENDING_DELETE, &gl->gl_flags);
- spin_unlock(&gl->gl_lockref.lock);
- return queued;
- }
- void gfs2_cancel_delete_work(struct gfs2_glock *gl)
- {
- if (cancel_delayed_work(&gl->gl_delete)) {
- clear_bit(GLF_PENDING_DELETE, &gl->gl_flags);
- gfs2_glock_put(gl);
- }
- }
- bool gfs2_delete_work_queued(const struct gfs2_glock *gl)
- {
- return test_bit(GLF_PENDING_DELETE, &gl->gl_flags);
- }
- static void flush_delete_work(struct gfs2_glock *gl)
- {
- if (gl->gl_name.ln_type == LM_TYPE_IOPEN) {
- if (cancel_delayed_work(&gl->gl_delete)) {
- queue_delayed_work(gfs2_delete_workqueue,
- &gl->gl_delete, 0);
- }
- }
- }
- void gfs2_flush_delete_work(struct gfs2_sbd *sdp)
- {
- glock_hash_walk(flush_delete_work, sdp);
- flush_workqueue(gfs2_delete_workqueue);
- }
- /**
- * 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))
- return;
- if (!lockref_get_not_dead(&gl->gl_lockref))
- return;
- set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
- gfs2_glock_queue_work(gl, 0);
- }
- /**
- * 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_lockref.lock);
- if (!__lockref_is_dead(&gl->gl_lockref)) {
- gl->gl_lockref.count++;
- if (gl->gl_state != LM_ST_UNLOCKED)
- handle_callback(gl, LM_ST_UNLOCKED, 0, false);
- __gfs2_glock_queue_work(gl, 0);
- }
- spin_unlock(&gl->gl_lockref.lock);
- }
- /**
- * 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 void dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid)
- {
- spin_lock(&gl->gl_lockref.lock);
- gfs2_dump_glock(seq, gl, fsid);
- spin_unlock(&gl->gl_lockref.lock);
- }
- static void dump_glock_func(struct gfs2_glock *gl)
- {
- dump_glock(NULL, gl, true);
- }
- static void withdraw_dq(struct gfs2_glock *gl)
- {
- spin_lock(&gl->gl_lockref.lock);
- if (!__lockref_is_dead(&gl->gl_lockref) &&
- glock_blocked_by_withdraw(gl))
- do_error(gl, LM_OUT_ERROR); /* remove pending waiters */
- spin_unlock(&gl->gl_lockref.lock);
- }
- void gfs2_gl_dq_holders(struct gfs2_sbd *sdp)
- {
- glock_hash_walk(withdraw_dq, sdp);
- }
- /**
- * gfs2_gl_hash_clear - Empty out the glock hash table
- * @sdp: the filesystem
- *
- * 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_timeout(sdp->sd_glock_wait,
- atomic_read(&sdp->sd_glock_disposal) == 0,
- HZ * 600);
- glock_hash_walk(dump_glock_func, sdp);
- }
- 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, u16 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 & LM_FLAG_NODE_SCOPE)
- *p++ = 'n';
- 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_MAY_DEMOTE, &iflags))
- *p++ = 'D';
- if (flags & GL_SKIP)
- *p++ = 's';
- *p = 0;
- return buf;
- }
- /**
- * dump_holder - print information about a glock holder
- * @seq: the seq_file struct
- * @gh: the glock holder
- * @fs_id_buf: pointer to file system id (if requested)
- *
- */
- static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh,
- const char *fs_id_buf)
- {
- const char *comm = "(none)";
- pid_t owner_pid = 0;
- char flags_buf[32];
- rcu_read_lock();
- if (pid_is_meaningful(gh)) {
- struct task_struct *gh_owner;
- comm = "(ended)";
- owner_pid = pid_nr(gh->gh_owner_pid);
- gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
- if (gh_owner)
- comm = gh_owner->comm;
- }
- gfs2_print_dbg(seq, "%s H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
- fs_id_buf, state2str(gh->gh_state),
- hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
- gh->gh_error, (long)owner_pid, comm, (void *)gh->gh_ip);
- rcu_read_unlock();
- }
- 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 (!list_empty(&gl->gl_holders))
- *p++ = 'q';
- if (test_bit(GLF_LRU, gflags))
- *p++ = 'L';
- if (gl->gl_object)
- *p++ = 'o';
- if (test_bit(GLF_BLOCKING, gflags))
- *p++ = 'b';
- if (test_bit(GLF_PENDING_DELETE, gflags))
- *p++ = 'P';
- if (test_bit(GLF_FREEING, gflags))
- *p++ = 'x';
- if (test_bit(GLF_INSTANTIATE_NEEDED, gflags))
- *p++ = 'n';
- if (test_bit(GLF_INSTANTIATE_IN_PROG, gflags))
- *p++ = 'N';
- *p = 0;
- return buf;
- }
- /**
- * gfs2_dump_glock - print information about a glock
- * @seq: The seq_file struct
- * @gl: the glock
- * @fsid: If true, also dump the file system id
- *
- * 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.
- *
- */
- void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid)
- {
- const struct gfs2_glock_operations *glops = gl->gl_ops;
- unsigned long long dtime;
- const struct gfs2_holder *gh;
- char gflags_buf[32];
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- char fs_id_buf[sizeof(sdp->sd_fsname) + 7];
- unsigned long nrpages = 0;
- if (gl->gl_ops->go_flags & GLOF_ASPACE) {
- struct address_space *mapping = gfs2_glock2aspace(gl);
- nrpages = mapping->nrpages;
- }
- memset(fs_id_buf, 0, sizeof(fs_id_buf));
- if (fsid && sdp) /* safety precaution */
- sprintf(fs_id_buf, "fsid=%s: ", sdp->sd_fsname);
- 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, "%sG: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d "
- "v:%d r:%d m:%ld p:%lu\n",
- fs_id_buf, 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),
- (int)gl->gl_lockref.count, gl->gl_hold_time, nrpages);
- list_for_each_entry(gh, &gl->gl_holders, gh_list)
- dump_holder(seq, gh, fs_id_buf);
- if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
- glops->go_dump(seq, gl, fs_id_buf);
- }
- 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:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n",
- gl->gl_name.ln_type,
- (unsigned long long)gl->gl_name.ln_number,
- (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
- (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
- (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
- (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
- (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
- (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
- (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
- (unsigned 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_sbd *sdp = seq->private;
- loff_t pos = *(loff_t *)iter_ptr;
- unsigned index = pos >> 3;
- unsigned subindex = pos & 0x07;
- 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)
- seq_printf(seq, " %15u", i);
- else
- seq_printf(seq, " %15llu", (unsigned long long)lkstats->
- lkstats[index - 1].stats[subindex]);
- }
- seq_putc(seq, '\n');
- return 0;
- }
- int __init gfs2_glock_init(void)
- {
- int i, ret;
- ret = rhashtable_init(&gl_hash_table, &ht_parms);
- if (ret < 0)
- return ret;
- glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
- WQ_HIGHPRI | WQ_FREEZABLE, 0);
- if (!glock_workqueue) {
- rhashtable_destroy(&gl_hash_table);
- return -ENOMEM;
- }
- gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
- WQ_MEM_RECLAIM | WQ_FREEZABLE,
- 0);
- if (!gfs2_delete_workqueue) {
- destroy_workqueue(glock_workqueue);
- rhashtable_destroy(&gl_hash_table);
- return -ENOMEM;
- }
- ret = register_shrinker(&glock_shrinker, "gfs2-glock");
- if (ret) {
- destroy_workqueue(gfs2_delete_workqueue);
- destroy_workqueue(glock_workqueue);
- rhashtable_destroy(&gl_hash_table);
- return ret;
- }
- for (i = 0; i < GLOCK_WAIT_TABLE_SIZE; i++)
- init_waitqueue_head(glock_wait_table + i);
- return 0;
- }
- void gfs2_glock_exit(void)
- {
- unregister_shrinker(&glock_shrinker);
- rhashtable_destroy(&gl_hash_table);
- destroy_workqueue(glock_workqueue);
- destroy_workqueue(gfs2_delete_workqueue);
- }
- static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi, loff_t n)
- {
- struct gfs2_glock *gl = gi->gl;
- if (gl) {
- if (n == 0)
- return;
- if (!lockref_put_not_zero(&gl->gl_lockref))
- gfs2_glock_queue_put(gl);
- }
- for (;;) {
- gl = rhashtable_walk_next(&gi->hti);
- if (IS_ERR_OR_NULL(gl)) {
- if (gl == ERR_PTR(-EAGAIN)) {
- n = 1;
- continue;
- }
- gl = NULL;
- break;
- }
- if (gl->gl_name.ln_sbd != gi->sdp)
- continue;
- if (n <= 1) {
- if (!lockref_get_not_dead(&gl->gl_lockref))
- continue;
- break;
- } else {
- if (__lockref_is_dead(&gl->gl_lockref))
- continue;
- n--;
- }
- }
- gi->gl = gl;
- }
- static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(RCU)
- {
- struct gfs2_glock_iter *gi = seq->private;
- loff_t n;
- /*
- * We can either stay where we are, skip to the next hash table
- * entry, or start from the beginning.
- */
- if (*pos < gi->last_pos) {
- rhashtable_walk_exit(&gi->hti);
- rhashtable_walk_enter(&gl_hash_table, &gi->hti);
- n = *pos + 1;
- } else {
- n = *pos - gi->last_pos;
- }
- rhashtable_walk_start(&gi->hti);
- gfs2_glock_iter_next(gi, 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;
- gfs2_glock_iter_next(gi, 1);
- return gi->gl;
- }
- static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
- __releases(RCU)
- {
- struct gfs2_glock_iter *gi = seq->private;
- rhashtable_walk_stop(&gi->hti);
- }
- static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
- {
- dump_glock(seq, iter_ptr, false);
- return 0;
- }
- static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
- {
- preempt_disable();
- if (*pos >= GFS2_NR_SBSTATS)
- return NULL;
- return pos;
- }
- static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
- loff_t *pos)
- {
- (*pos)++;
- if (*pos >= GFS2_NR_SBSTATS)
- return NULL;
- return pos;
- }
- 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_sops = {
- .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,
- const struct seq_operations *ops)
- {
- int ret = seq_open_private(file, 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;
- /*
- * Initially, we are "before" the first hash table entry; the
- * first call to rhashtable_walk_next gets us the first entry.
- */
- gi->last_pos = -1;
- gi->gl = NULL;
- rhashtable_walk_enter(&gl_hash_table, &gi->hti);
- }
- return ret;
- }
- static int gfs2_glocks_open(struct inode *inode, struct file *file)
- {
- return __gfs2_glocks_open(inode, file, &gfs2_glock_seq_ops);
- }
- static int gfs2_glocks_release(struct inode *inode, struct file *file)
- {
- struct seq_file *seq = file->private_data;
- struct gfs2_glock_iter *gi = seq->private;
- if (gi->gl)
- gfs2_glock_put(gi->gl);
- rhashtable_walk_exit(&gi->hti);
- return seq_release_private(inode, file);
- }
- static int gfs2_glstats_open(struct inode *inode, struct file *file)
- {
- return __gfs2_glocks_open(inode, file, &gfs2_glstats_seq_ops);
- }
- static const struct file_operations gfs2_glocks_fops = {
- .owner = THIS_MODULE,
- .open = gfs2_glocks_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = gfs2_glocks_release,
- };
- static const struct file_operations gfs2_glstats_fops = {
- .owner = THIS_MODULE,
- .open = gfs2_glstats_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = gfs2_glocks_release,
- };
- struct gfs2_glockfd_iter {
- struct super_block *sb;
- unsigned int tgid;
- struct task_struct *task;
- unsigned int fd;
- struct file *file;
- };
- static struct task_struct *gfs2_glockfd_next_task(struct gfs2_glockfd_iter *i)
- {
- struct pid_namespace *ns = task_active_pid_ns(current);
- struct pid *pid;
- if (i->task)
- put_task_struct(i->task);
- rcu_read_lock();
- retry:
- i->task = NULL;
- pid = find_ge_pid(i->tgid, ns);
- if (pid) {
- i->tgid = pid_nr_ns(pid, ns);
- i->task = pid_task(pid, PIDTYPE_TGID);
- if (!i->task) {
- i->tgid++;
- goto retry;
- }
- get_task_struct(i->task);
- }
- rcu_read_unlock();
- return i->task;
- }
- static struct file *gfs2_glockfd_next_file(struct gfs2_glockfd_iter *i)
- {
- if (i->file) {
- fput(i->file);
- i->file = NULL;
- }
- rcu_read_lock();
- for(;; i->fd++) {
- struct inode *inode;
- i->file = task_lookup_next_fd_rcu(i->task, &i->fd);
- if (!i->file) {
- i->fd = 0;
- break;
- }
- inode = file_inode(i->file);
- if (inode->i_sb != i->sb)
- continue;
- if (get_file_rcu(i->file))
- break;
- }
- rcu_read_unlock();
- return i->file;
- }
- static void *gfs2_glockfd_seq_start(struct seq_file *seq, loff_t *pos)
- {
- struct gfs2_glockfd_iter *i = seq->private;
- if (*pos)
- return NULL;
- while (gfs2_glockfd_next_task(i)) {
- if (gfs2_glockfd_next_file(i))
- return i;
- i->tgid++;
- }
- return NULL;
- }
- static void *gfs2_glockfd_seq_next(struct seq_file *seq, void *iter_ptr,
- loff_t *pos)
- {
- struct gfs2_glockfd_iter *i = seq->private;
- (*pos)++;
- i->fd++;
- do {
- if (gfs2_glockfd_next_file(i))
- return i;
- i->tgid++;
- } while (gfs2_glockfd_next_task(i));
- return NULL;
- }
- static void gfs2_glockfd_seq_stop(struct seq_file *seq, void *iter_ptr)
- {
- struct gfs2_glockfd_iter *i = seq->private;
- if (i->file)
- fput(i->file);
- if (i->task)
- put_task_struct(i->task);
- }
- static void gfs2_glockfd_seq_show_flock(struct seq_file *seq,
- struct gfs2_glockfd_iter *i)
- {
- struct gfs2_file *fp = i->file->private_data;
- struct gfs2_holder *fl_gh = &fp->f_fl_gh;
- struct lm_lockname gl_name = { .ln_type = LM_TYPE_RESERVED };
- if (!READ_ONCE(fl_gh->gh_gl))
- return;
- spin_lock(&i->file->f_lock);
- if (gfs2_holder_initialized(fl_gh))
- gl_name = fl_gh->gh_gl->gl_name;
- spin_unlock(&i->file->f_lock);
- if (gl_name.ln_type != LM_TYPE_RESERVED) {
- seq_printf(seq, "%d %u %u/%llx\n",
- i->tgid, i->fd, gl_name.ln_type,
- (unsigned long long)gl_name.ln_number);
- }
- }
- static int gfs2_glockfd_seq_show(struct seq_file *seq, void *iter_ptr)
- {
- struct gfs2_glockfd_iter *i = seq->private;
- struct inode *inode = file_inode(i->file);
- struct gfs2_glock *gl;
- inode_lock_shared(inode);
- gl = GFS2_I(inode)->i_iopen_gh.gh_gl;
- if (gl) {
- seq_printf(seq, "%d %u %u/%llx\n",
- i->tgid, i->fd, gl->gl_name.ln_type,
- (unsigned long long)gl->gl_name.ln_number);
- }
- gfs2_glockfd_seq_show_flock(seq, i);
- inode_unlock_shared(inode);
- return 0;
- }
- static const struct seq_operations gfs2_glockfd_seq_ops = {
- .start = gfs2_glockfd_seq_start,
- .next = gfs2_glockfd_seq_next,
- .stop = gfs2_glockfd_seq_stop,
- .show = gfs2_glockfd_seq_show,
- };
- static int gfs2_glockfd_open(struct inode *inode, struct file *file)
- {
- struct gfs2_glockfd_iter *i;
- struct gfs2_sbd *sdp = inode->i_private;
- i = __seq_open_private(file, &gfs2_glockfd_seq_ops,
- sizeof(struct gfs2_glockfd_iter));
- if (!i)
- return -ENOMEM;
- i->sb = sdp->sd_vfs;
- return 0;
- }
- static const struct file_operations gfs2_glockfd_fops = {
- .owner = THIS_MODULE,
- .open = gfs2_glockfd_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release_private,
- };
- DEFINE_SEQ_ATTRIBUTE(gfs2_sbstats);
- void gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
- {
- sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
- debugfs_create_file("glocks", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
- &gfs2_glocks_fops);
- debugfs_create_file("glockfd", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
- &gfs2_glockfd_fops);
- debugfs_create_file("glstats", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
- &gfs2_glstats_fops);
- debugfs_create_file("sbstats", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
- &gfs2_sbstats_fops);
- }
- void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
- {
- debugfs_remove_recursive(sdp->debugfs_dir);
- sdp->debugfs_dir = NULL;
- }
- void gfs2_register_debugfs(void)
- {
- gfs2_root = debugfs_create_dir("gfs2", NULL);
- }
- void gfs2_unregister_debugfs(void)
- {
- debugfs_remove(gfs2_root);
- gfs2_root = NULL;
- }
|