--- /dev/null
+/*
+ * 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.
+ */
+
+#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/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 <linux/lockref.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
+ *
+ */
+
+static 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;
+ 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)
+{
+ spin_lock(&lru_lock);
+ if (!list_empty(&gl->gl_lru)) {
+ list_del_init(&gl->gl_lru);
+ atomic_dec(&lru_count);
+ clear_bit(GLF_LRU, &gl->gl_flags);
+ }
+ spin_unlock(&lru_lock);
+}
+
+/**
+ * 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 (lockref_put_or_lock(&gl->gl_lockref))
+ return;
+
+ lockref_mark_dead(&gl->gl_lockref);
+
+ gfs2_glock_remove_from_lru(gl);
+ spin_unlock(&gl->gl_lockref.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 (lockref_get_not_dead(&gl->gl_lockref))
+ 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_atomic();
+ 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) {
+ GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
+ if (held2)
+ gl->gl_lockref.count++;
+ else
+ gl->gl_lockref.count--;
+ }
+ 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_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;
+ 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 */
+ pr_err("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) {
+ pr_err("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_atomic();
+ gl->gl_lockref.count++;
+ if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
+ gl->gl_lockref.count--;
+ return;
+
+out_unlock:
+ clear_bit(GLF_LOCK, &gl->gl_flags);
+ smp_mb__after_atomic();
+ 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_NOFS);
+ 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_NOFS);
+ 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;
+ 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_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->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 = _RET_IP_;
+ 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 = _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);
+ gh->gh_gl = NULL;
+ gh->gh_ip = 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, 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;
+
+ pr_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:
+ pr_err("original: %pSR\n", (void *)gh2->gh_ip);
+ pr_err("pid: %d\n", pid_nr(gh2->gh_owner_pid));
+ pr_err("lock type: %d req lock state : %d\n",
+ gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
+ pr_err("new: %pSR\n", (void *)gh->gh_ip);
+ pr_err("pid: %d\n", pid_nr(gh->gh_owner_pid));
+ pr_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 (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++;
+ if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
+ gl->gl_lockref.count--;
+ }
+ 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, 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;
+ }
+ }
+
+ gl->gl_lockref.count++;
+ set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
+ spin_unlock(&gl->gl_spin);
+
+ 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);
+ if (!spin_trylock(&gl->gl_spin)) {
+add_back_to_lru:
+ list_add(&gl->gl_lru, &lru_list);
+ atomic_inc(&lru_count);
+ continue;
+ }
+ if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
+ spin_unlock(&gl->gl_spin);
+ goto add_back_to_lru;
+ }
+ clear_bit(GLF_LRU, &gl->gl_flags);
+ 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));
+ if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
+ gl->gl_lockref.count--;
+ spin_unlock(&gl->gl_spin);
+ 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_entry(lru_list.next, 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,
+};
+
+/**
+ * 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) && lockref_get_not_dead(&gl->gl_lockref))
+ 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 void dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
+{
+ spin_lock(&gl->gl_spin);
+ gfs2_dump_glock(seq, gl);
+ spin_unlock(&gl->gl_spin);
+}
+
+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
+ *
+ */
+
+static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
+{
+ struct task_struct *gh_owner = NULL;
+ char flags_buf[32];
+
+ rcu_read_lock();
+ 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);
+ 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 (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.
+ *
+ */
+
+void 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];
+
+ 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),
+ (int)gl->gl_lockref.count, gl->gl_hold_time);
+
+ list_for_each_entry(gh, &gl->gl_holders, gh_list)
+ dump_holder(seq, gh);
+
+ if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
+ glops->go_dump(seq, gl);
+}
+
+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 ||
+ __lockref_is_dead(&gi->gl->gl_lockref));
+
+ 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)
+{
+ dump_glock(seq, iter_ptr);
+ return 0;
+}
+
+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)
+{
+ struct dentry *dent;
+
+ dent = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
+ if (IS_ERR_OR_NULL(dent))
+ goto fail;
+ sdp->debugfs_dir = dent;
+
+ dent = debugfs_create_file("glocks",
+ S_IFREG | S_IRUGO,
+ sdp->debugfs_dir, sdp,
+ &gfs2_glocks_fops);
+ if (IS_ERR_OR_NULL(dent))
+ goto fail;
+ sdp->debugfs_dentry_glocks = dent;
+
+ dent = debugfs_create_file("glstats",
+ S_IFREG | S_IRUGO,
+ sdp->debugfs_dir, sdp,
+ &gfs2_glstats_fops);
+ if (IS_ERR_OR_NULL(dent))
+ goto fail;
+ sdp->debugfs_dentry_glstats = dent;
+
+ dent = debugfs_create_file("sbstats",
+ S_IFREG | S_IRUGO,
+ sdp->debugfs_dir, sdp,
+ &gfs2_sbstats_fops);
+ if (IS_ERR_OR_NULL(dent))
+ goto fail;
+ sdp->debugfs_dentry_sbstats = dent;
+
+ return 0;
+fail:
+ gfs2_delete_debugfs_file(sdp);
+ return dent ? PTR_ERR(dent) : -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);
+ if (IS_ERR(gfs2_root))
+ return PTR_ERR(gfs2_root);
+ return gfs2_root ? 0 : -ENOMEM;
+}
+
+void gfs2_unregister_debugfs(void)
+{
+ debugfs_remove(gfs2_root);
+ gfs2_root = NULL;
+}
Code Review / kvmfornfv.git / blobdiff