--- /dev/null
+/*
+ * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License version 2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.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/lm_interface.h>
+#include <linux/wait.h>
+#include <linux/module.h>
+#include <linux/rwsem.h>
+#include <asm/uaccess.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "glock.h"
+#include "glops.h"
+#include "inode.h"
+#include "lm.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "quota.h"
+#include "super.h"
+#include "util.h"
+
+struct gfs2_gl_hash_bucket {
+ struct hlist_head hb_list;
+};
+
+struct glock_iter {
+ int hash; /* hash bucket index */
+ struct gfs2_sbd *sdp; /* incore superblock */
+ struct gfs2_glock *gl; /* current glock struct */
+ struct hlist_head *hb_list; /* current hash bucket ptr */
+ struct seq_file *seq; /* sequence file for debugfs */
+ char string[512]; /* scratch space */
+};
+
+typedef void (*glock_examiner) (struct gfs2_glock * gl);
+
+static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
+static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl);
+static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh);
+static void gfs2_glock_drop_th(struct gfs2_glock *gl);
+static DECLARE_RWSEM(gfs2_umount_flush_sem);
+static struct dentry *gfs2_root;
+
+#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 gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
+static struct dentry *gfs2_root;
+
+/*
+ * Despite what you might think, the numbers below are not arbitrary :-)
+ * They are taken from the ipv4 routing hash code, which is well tested
+ * and thus should be nearly optimal. Later on we might tweek the numbers
+ * but for now this should be fine.
+ *
+ * The reason for putting the locks in a separate array from the list heads
+ * is that we can have fewer locks than list heads and save memory. We use
+ * the same hash function for both, but with a different hash mask.
+ */
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
+ defined(CONFIG_PROVE_LOCKING)
+
+#ifdef CONFIG_LOCKDEP
+# define GL_HASH_LOCK_SZ 256
+#else
+# if NR_CPUS >= 32
+# define GL_HASH_LOCK_SZ 4096
+# elif NR_CPUS >= 16
+# define GL_HASH_LOCK_SZ 2048
+# elif NR_CPUS >= 8
+# define GL_HASH_LOCK_SZ 1024
+# elif NR_CPUS >= 4
+# define GL_HASH_LOCK_SZ 512
+# else
+# define GL_HASH_LOCK_SZ 256
+# endif
+#endif
+
+/* We never want more locks than chains */
+#if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
+# undef GL_HASH_LOCK_SZ
+# define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
+#endif
+
+static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
+
+static inline rwlock_t *gl_lock_addr(unsigned int x)
+{
+ return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
+}
+#else /* not SMP, so no spinlocks required */
+static inline rwlock_t *gl_lock_addr(unsigned int x)
+{
+ return NULL;
+}
+#endif
+
+/**
+ * relaxed_state_ok - is a requested lock compatible with the current lock mode?
+ * @actual: the current state of the lock
+ * @requested: the lock state that was requested by the caller
+ * @flags: the modifier flags passed in by the caller
+ *
+ * Returns: 1 if the locks are compatible, 0 otherwise
+ */
+
+static inline int relaxed_state_ok(unsigned int actual, unsigned requested,
+ int flags)
+{
+ if (actual == requested)
+ return 1;
+
+ if (flags & GL_EXACT)
+ return 0;
+
+ if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED)
+ return 1;
+
+ if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY))
+ return 1;
+
+ return 0;
+}
+
+/**
+ * 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;
+}
+
+/**
+ * glock_free() - Perform a few checks and then release struct gfs2_glock
+ * @gl: The glock to release
+ *
+ * Also calls lock module to release its internal structure for this glock.
+ *
+ */
+
+static void glock_free(struct gfs2_glock *gl)
+{
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ struct inode *aspace = gl->gl_aspace;
+
+ gfs2_lm_put_lock(sdp, gl->gl_lock);
+
+ if (aspace)
+ gfs2_aspace_put(aspace);
+
+ kmem_cache_free(gfs2_glock_cachep, gl);
+}
+
+/**
+ * gfs2_glock_hold() - increment reference count on glock
+ * @gl: The glock to hold
+ *
+ */
+
+void gfs2_glock_hold(struct gfs2_glock *gl)
+{
+ atomic_inc(&gl->gl_ref);
+}
+
+/**
+ * gfs2_glock_put() - Decrement reference count on glock
+ * @gl: The glock to put
+ *
+ */
+
+int gfs2_glock_put(struct gfs2_glock *gl)
+{
+ int rv = 0;
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+
+ write_lock(gl_lock_addr(gl->gl_hash));
+ if (atomic_dec_and_test(&gl->gl_ref)) {
+ hlist_del(&gl->gl_list);
+ write_unlock(gl_lock_addr(gl->gl_hash));
+ BUG_ON(spin_is_locked(&gl->gl_spin));
+ gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED);
+ gfs2_assert(sdp, list_empty(&gl->gl_reclaim));
+ gfs2_assert(sdp, list_empty(&gl->gl_holders));
+ gfs2_assert(sdp, list_empty(&gl->gl_waiters1));
+ gfs2_assert(sdp, list_empty(&gl->gl_waiters3));
+ glock_free(gl);
+ rv = 1;
+ goto out;
+ }
+ write_unlock(gl_lock_addr(gl->gl_hash));
+out:
+ return rv;
+}
+
+/**
+ * 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_node *h;
+
+ hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
+ if (!lm_name_equal(&gl->gl_name, name))
+ continue;
+ if (gl->gl_sbd != sdp)
+ continue;
+
+ atomic_inc(&gl->gl_ref);
+
+ return gl;
+ }
+
+ return NULL;
+}
+
+/**
+ * gfs2_glock_find() - Find glock by lock number
+ * @sdp: The GFS2 superblock
+ * @name: The lock name
+ *
+ * Returns: NULL, or the struct gfs2_glock with the requested number
+ */
+
+static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp,
+ const struct lm_lockname *name)
+{
+ unsigned int hash = gl_hash(sdp, name);
+ struct gfs2_glock *gl;
+
+ read_lock(gl_lock_addr(hash));
+ gl = search_bucket(hash, sdp, name);
+ read_unlock(gl_lock_addr(hash));
+
+ 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 lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
+ struct gfs2_glock *gl, *tmp;
+ unsigned int hash = gl_hash(sdp, &name);
+ int error;
+
+ read_lock(gl_lock_addr(hash));
+ gl = search_bucket(hash, sdp, &name);
+ read_unlock(gl_lock_addr(hash));
+
+ if (gl || !create) {
+ *glp = gl;
+ return 0;
+ }
+
+ gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
+ if (!gl)
+ return -ENOMEM;
+
+ gl->gl_flags = 0;
+ gl->gl_name = name;
+ atomic_set(&gl->gl_ref, 1);
+ gl->gl_state = LM_ST_UNLOCKED;
+ gl->gl_hash = hash;
+ gl->gl_owner_pid = 0;
+ gl->gl_ip = 0;
+ gl->gl_ops = glops;
+ gl->gl_req_gh = NULL;
+ gl->gl_req_bh = NULL;
+ gl->gl_vn = 0;
+ gl->gl_stamp = jiffies;
+ gl->gl_object = NULL;
+ gl->gl_sbd = sdp;
+ gl->gl_aspace = NULL;
+ lops_init_le(&gl->gl_le, &gfs2_glock_lops);
+
+ /* If this glock protects actual on-disk data or metadata blocks,
+ create a VFS inode to manage the pages/buffers holding them. */
+ if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) {
+ gl->gl_aspace = gfs2_aspace_get(sdp);
+ if (!gl->gl_aspace) {
+ error = -ENOMEM;
+ goto fail;
+ }
+ }
+
+ error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock);
+ if (error)
+ goto fail_aspace;
+
+ write_lock(gl_lock_addr(hash));
+ tmp = search_bucket(hash, sdp, &name);
+ if (tmp) {
+ write_unlock(gl_lock_addr(hash));
+ glock_free(gl);
+ gl = tmp;
+ } else {
+ hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
+ write_unlock(gl_lock_addr(hash));
+ }
+
+ *glp = gl;
+
+ return 0;
+
+fail_aspace:
+ if (gl->gl_aspace)
+ gfs2_aspace_put(gl->gl_aspace);
+fail:
+ kmem_cache_free(gfs2_glock_cachep, gl);
+ return error;
+}
+
+/**
+ * gfs2_holder_init - initialize a struct gfs2_holder in the default way
+ * @gl: the glock
+ * @state: the state we're requesting
+ * @flags: the modifier flags
+ * @gh: the holder structure
+ *
+ */
+
+void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
+ struct gfs2_holder *gh)
+{
+ INIT_LIST_HEAD(&gh->gh_list);
+ gh->gh_gl = gl;
+ gh->gh_ip = (unsigned long)__builtin_return_address(0);
+ gh->gh_owner_pid = current->pid;
+ gh->gh_state = state;
+ gh->gh_flags = flags;
+ gh->gh_error = 0;
+ gh->gh_iflags = 0;
+ gfs2_glock_hold(gl);
+}
+
+/**
+ * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
+ * @state: the state we're requesting
+ * @flags: the modifier flags
+ * @gh: the holder structure
+ *
+ * Don't mess with the glock.
+ *
+ */
+
+void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
+{
+ gh->gh_state = state;
+ gh->gh_flags = flags;
+ gh->gh_iflags = 0;
+ gh->gh_ip = (unsigned long)__builtin_return_address(0);
+}
+
+/**
+ * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
+ * @gh: the holder structure
+ *
+ */
+
+void gfs2_holder_uninit(struct gfs2_holder *gh)
+{
+ gfs2_glock_put(gh->gh_gl);
+ gh->gh_gl = NULL;
+ gh->gh_ip = 0;
+}
+
+static void gfs2_holder_wake(struct gfs2_holder *gh)
+{
+ clear_bit(HIF_WAIT, &gh->gh_iflags);
+ smp_mb();
+ wake_up_bit(&gh->gh_iflags, HIF_WAIT);
+}
+
+static int holder_wait(void *word)
+{
+ schedule();
+ return 0;
+}
+
+static void wait_on_holder(struct gfs2_holder *gh)
+{
+ might_sleep();
+ wait_on_bit(&gh->gh_iflags, HIF_WAIT, holder_wait, TASK_UNINTERRUPTIBLE);
+}
+
+/**
+ * rq_mutex - process a mutex request in the queue
+ * @gh: the glock holder
+ *
+ * Returns: 1 if the queue is blocked
+ */
+
+static int rq_mutex(struct gfs2_holder *gh)
+{
+ struct gfs2_glock *gl = gh->gh_gl;
+
+ list_del_init(&gh->gh_list);
+ /* gh->gh_error never examined. */
+ set_bit(GLF_LOCK, &gl->gl_flags);
+ clear_bit(HIF_WAIT, &gh->gh_iflags);
+ smp_mb();
+ wake_up_bit(&gh->gh_iflags, HIF_WAIT);
+
+ return 1;
+}
+
+/**
+ * rq_promote - process a promote request in the queue
+ * @gh: the glock holder
+ *
+ * Acquire a new inter-node lock, or change a lock state to more restrictive.
+ *
+ * Returns: 1 if the queue is blocked
+ */
+
+static int rq_promote(struct gfs2_holder *gh)
+{
+ struct gfs2_glock *gl = gh->gh_gl;
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+
+ if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
+ if (list_empty(&gl->gl_holders)) {
+ gl->gl_req_gh = gh;
+ set_bit(GLF_LOCK, &gl->gl_flags);
+ spin_unlock(&gl->gl_spin);
+
+ if (atomic_read(&sdp->sd_reclaim_count) >
+ gfs2_tune_get(sdp, gt_reclaim_limit) &&
+ !(gh->gh_flags & LM_FLAG_PRIORITY)) {
+ gfs2_reclaim_glock(sdp);
+ gfs2_reclaim_glock(sdp);
+ }
+
+ gfs2_glock_xmote_th(gh->gh_gl, gh);
+ spin_lock(&gl->gl_spin);
+ }
+ return 1;
+ }
+
+ if (list_empty(&gl->gl_holders)) {
+ set_bit(HIF_FIRST, &gh->gh_iflags);
+ set_bit(GLF_LOCK, &gl->gl_flags);
+ } else {
+ struct gfs2_holder *next_gh;
+ if (gh->gh_state == LM_ST_EXCLUSIVE)
+ return 1;
+ next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder,
+ gh_list);
+ if (next_gh->gh_state == LM_ST_EXCLUSIVE)
+ return 1;
+ }
+
+ list_move_tail(&gh->gh_list, &gl->gl_holders);
+ gh->gh_error = 0;
+ set_bit(HIF_HOLDER, &gh->gh_iflags);
+
+ gfs2_holder_wake(gh);
+
+ return 0;
+}
+
+/**
+ * rq_demote - process a demote request in the queue
+ * @gh: the glock holder
+ *
+ * Returns: 1 if the queue is blocked
+ */
+
+static int rq_demote(struct gfs2_glock *gl)
+{
+ if (!list_empty(&gl->gl_holders))
+ return 1;
+
+ if (gl->gl_state == gl->gl_demote_state ||
+ gl->gl_state == LM_ST_UNLOCKED) {
+ clear_bit(GLF_DEMOTE, &gl->gl_flags);
+ return 0;
+ }
+ set_bit(GLF_LOCK, &gl->gl_flags);
+ spin_unlock(&gl->gl_spin);
+ if (gl->gl_demote_state == LM_ST_UNLOCKED ||
+ gl->gl_state != LM_ST_EXCLUSIVE)
+ gfs2_glock_drop_th(gl);
+ else
+ gfs2_glock_xmote_th(gl, NULL);
+ spin_lock(&gl->gl_spin);
+
+ return 0;
+}
+
+/**
+ * run_queue - process holder structures on a glock
+ * @gl: the glock
+ *
+ */
+static void run_queue(struct gfs2_glock *gl)
+{
+ struct gfs2_holder *gh;
+ int blocked = 1;
+
+ for (;;) {
+ if (test_bit(GLF_LOCK, &gl->gl_flags))
+ break;
+
+ if (!list_empty(&gl->gl_waiters1)) {
+ gh = list_entry(gl->gl_waiters1.next,
+ struct gfs2_holder, gh_list);
+
+ if (test_bit(HIF_MUTEX, &gh->gh_iflags))
+ blocked = rq_mutex(gh);
+ else
+ gfs2_assert_warn(gl->gl_sbd, 0);
+
+ } else if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
+ blocked = rq_demote(gl);
+ } else if (!list_empty(&gl->gl_waiters3)) {
+ gh = list_entry(gl->gl_waiters3.next,
+ struct gfs2_holder, gh_list);
+
+ if (test_bit(HIF_PROMOTE, &gh->gh_iflags))
+ blocked = rq_promote(gh);
+ else
+ gfs2_assert_warn(gl->gl_sbd, 0);
+
+ } else
+ break;
+
+ if (blocked)
+ break;
+ }
+}
+
+/**
+ * gfs2_glmutex_lock - acquire a local lock on a glock
+ * @gl: the glock
+ *
+ * Gives caller exclusive access to manipulate a glock structure.
+ */
+
+static void gfs2_glmutex_lock(struct gfs2_glock *gl)
+{
+ struct gfs2_holder gh;
+
+ gfs2_holder_init(gl, 0, 0, &gh);
+ set_bit(HIF_MUTEX, &gh.gh_iflags);
+ if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags))
+ BUG();
+
+ spin_lock(&gl->gl_spin);
+ if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
+ list_add_tail(&gh.gh_list, &gl->gl_waiters1);
+ } else {
+ gl->gl_owner_pid = current->pid;
+ gl->gl_ip = (unsigned long)__builtin_return_address(0);
+ clear_bit(HIF_WAIT, &gh.gh_iflags);
+ smp_mb();
+ wake_up_bit(&gh.gh_iflags, HIF_WAIT);
+ }
+ spin_unlock(&gl->gl_spin);
+
+ wait_on_holder(&gh);
+ gfs2_holder_uninit(&gh);
+}
+
+/**
+ * gfs2_glmutex_trylock - try to acquire a local lock on a glock
+ * @gl: the glock
+ *
+ * Returns: 1 if the glock is acquired
+ */
+
+static int gfs2_glmutex_trylock(struct gfs2_glock *gl)
+{
+ int acquired = 1;
+
+ spin_lock(&gl->gl_spin);
+ if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
+ acquired = 0;
+ } else {
+ gl->gl_owner_pid = current->pid;
+ gl->gl_ip = (unsigned long)__builtin_return_address(0);
+ }
+ spin_unlock(&gl->gl_spin);
+
+ return acquired;
+}
+
+/**
+ * gfs2_glmutex_unlock - release a local lock on a glock
+ * @gl: the glock
+ *
+ */
+
+static void gfs2_glmutex_unlock(struct gfs2_glock *gl)
+{
+ spin_lock(&gl->gl_spin);
+ clear_bit(GLF_LOCK, &gl->gl_flags);
+ gl->gl_owner_pid = 0;
+ gl->gl_ip = 0;
+ run_queue(gl);
+ BUG_ON(!spin_is_locked(&gl->gl_spin));
+ spin_unlock(&gl->gl_spin);
+}
+
+/**
+ * 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)
+{
+ spin_lock(&gl->gl_spin);
+ if (test_and_set_bit(GLF_DEMOTE, &gl->gl_flags) == 0) {
+ gl->gl_demote_state = state;
+ gl->gl_demote_time = jiffies;
+ } else if (gl->gl_demote_state != LM_ST_UNLOCKED) {
+ gl->gl_demote_state = state;
+ }
+ spin_unlock(&gl->gl_spin);
+}
+
+/**
+ * state_change - record that the glock is now in a different state
+ * @gl: the glock
+ * @new_state the new state
+ *
+ */
+
+static void state_change(struct gfs2_glock *gl, unsigned int new_state)
+{
+ int held1, held2;
+
+ held1 = (gl->gl_state != LM_ST_UNLOCKED);
+ held2 = (new_state != LM_ST_UNLOCKED);
+
+ if (held1 != held2) {
+ if (held2)
+ gfs2_glock_hold(gl);
+ else
+ gfs2_glock_put(gl);
+ }
+
+ gl->gl_state = new_state;
+}
+
+/**
+ * xmote_bh - Called after the lock module is done acquiring a lock
+ * @gl: The glock in question
+ * @ret: the int returned from the lock module
+ *
+ */
+
+static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
+{
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ const struct gfs2_glock_operations *glops = gl->gl_ops;
+ struct gfs2_holder *gh = gl->gl_req_gh;
+ int prev_state = gl->gl_state;
+ int op_done = 1;
+
+ gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
+ gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
+ gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC));
+
+ state_change(gl, ret & LM_OUT_ST_MASK);
+
+ if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) {
+ if (glops->go_inval)
+ glops->go_inval(gl, DIO_METADATA);
+ } else if (gl->gl_state == LM_ST_DEFERRED) {
+ /* We might not want to do this here.
+ Look at moving to the inode glops. */
+ if (glops->go_inval)
+ glops->go_inval(gl, 0);
+ }
+
+ /* Deal with each possible exit condition */
+
+ if (!gh) {
+ gl->gl_stamp = jiffies;
+ if (ret & LM_OUT_CANCELED)
+ op_done = 0;
+ else
+ clear_bit(GLF_DEMOTE, &gl->gl_flags);
+ } else {
+ spin_lock(&gl->gl_spin);
+ list_del_init(&gh->gh_list);
+ gh->gh_error = -EIO;
+ if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+ goto out;
+ gh->gh_error = GLR_CANCELED;
+ if (ret & LM_OUT_CANCELED)
+ goto out;
+ if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
+ list_add_tail(&gh->gh_list, &gl->gl_holders);
+ gh->gh_error = 0;
+ set_bit(HIF_HOLDER, &gh->gh_iflags);
+ set_bit(HIF_FIRST, &gh->gh_iflags);
+ op_done = 0;
+ goto out;
+ }
+ gh->gh_error = GLR_TRYFAILED;
+ if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
+ goto out;
+ gh->gh_error = -EINVAL;
+ if (gfs2_assert_withdraw(sdp, 0) == -1)
+ fs_err(sdp, "ret = 0x%.8X\n", ret);
+out:
+ spin_unlock(&gl->gl_spin);
+ }
+
+ if (glops->go_xmote_bh)
+ glops->go_xmote_bh(gl);
+
+ if (op_done) {
+ spin_lock(&gl->gl_spin);
+ gl->gl_req_gh = NULL;
+ gl->gl_req_bh = NULL;
+ clear_bit(GLF_LOCK, &gl->gl_flags);
+ run_queue(gl);
+ spin_unlock(&gl->gl_spin);
+ }
+
+ gfs2_glock_put(gl);
+
+ if (gh)
+ gfs2_holder_wake(gh);
+}
+
+/**
+ * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
+ * @gl: The glock in question
+ * @state: the requested state
+ * @flags: modifier flags to the lock call
+ *
+ */
+
+void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh)
+{
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ int flags = gh ? gh->gh_flags : 0;
+ unsigned state = gh ? gh->gh_state : gl->gl_demote_state;
+ const struct gfs2_glock_operations *glops = gl->gl_ops;
+ int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB |
+ LM_FLAG_NOEXP | LM_FLAG_ANY |
+ LM_FLAG_PRIORITY);
+ unsigned int lck_ret;
+
+ if (glops->go_xmote_th)
+ glops->go_xmote_th(gl);
+
+ gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
+ gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
+ gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED);
+ gfs2_assert_warn(sdp, state != gl->gl_state);
+
+ gfs2_glock_hold(gl);
+ gl->gl_req_bh = xmote_bh;
+
+ lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags);
+
+ if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR)))
+ return;
+
+ if (lck_ret & LM_OUT_ASYNC)
+ gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC);
+ else
+ xmote_bh(gl, lck_ret);
+}
+
+/**
+ * drop_bh - Called after a lock module unlock completes
+ * @gl: the glock
+ * @ret: the return status
+ *
+ * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
+ * Doesn't drop the reference on the glock the top half took out
+ *
+ */
+
+static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
+{
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ const struct gfs2_glock_operations *glops = gl->gl_ops;
+ struct gfs2_holder *gh = gl->gl_req_gh;
+
+ gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
+ gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
+ gfs2_assert_warn(sdp, !ret);
+
+ state_change(gl, LM_ST_UNLOCKED);
+ clear_bit(GLF_DEMOTE, &gl->gl_flags);
+
+ if (glops->go_inval)
+ glops->go_inval(gl, DIO_METADATA);
+
+ if (gh) {
+ spin_lock(&gl->gl_spin);
+ list_del_init(&gh->gh_list);
+ gh->gh_error = 0;
+ spin_unlock(&gl->gl_spin);
+ }
+
+ spin_lock(&gl->gl_spin);
+ gl->gl_req_gh = NULL;
+ gl->gl_req_bh = NULL;
+ clear_bit(GLF_LOCK, &gl->gl_flags);
+ run_queue(gl);
+ spin_unlock(&gl->gl_spin);
+
+ gfs2_glock_put(gl);
+
+ if (gh)
+ gfs2_holder_wake(gh);
+}
+
+/**
+ * gfs2_glock_drop_th - call into the lock module to unlock a lock
+ * @gl: the glock
+ *
+ */
+
+static void gfs2_glock_drop_th(struct gfs2_glock *gl)
+{
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ const struct gfs2_glock_operations *glops = gl->gl_ops;
+ unsigned int ret;
+
+ if (glops->go_drop_th)
+ glops->go_drop_th(gl);
+
+ gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
+ gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
+ gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED);
+
+ gfs2_glock_hold(gl);
+ gl->gl_req_bh = drop_bh;
+
+ ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state);
+
+ if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR)))
+ return;
+
+ if (!ret)
+ drop_bh(gl, ret);
+ else
+ gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC);
+}
+
+/**
+ * do_cancels - cancel requests for locks stuck waiting on an expire flag
+ * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
+ *
+ * Don't cancel GL_NOCANCEL requests.
+ */
+
+static void do_cancels(struct gfs2_holder *gh)
+{
+ struct gfs2_glock *gl = gh->gh_gl;
+
+ spin_lock(&gl->gl_spin);
+
+ while (gl->gl_req_gh != gh &&
+ !test_bit(HIF_HOLDER, &gh->gh_iflags) &&
+ !list_empty(&gh->gh_list)) {
+ if (gl->gl_req_bh && !(gl->gl_req_gh &&
+ (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) {
+ spin_unlock(&gl->gl_spin);
+ gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock);
+ msleep(100);
+ spin_lock(&gl->gl_spin);
+ } else {
+ spin_unlock(&gl->gl_spin);
+ msleep(100);
+ spin_lock(&gl->gl_spin);
+ }
+ }
+
+ spin_unlock(&gl->gl_spin);
+}
+
+/**
+ * glock_wait_internal - wait on a glock acquisition
+ * @gh: the glock holder
+ *
+ * Returns: 0 on success
+ */
+
+static int glock_wait_internal(struct gfs2_holder *gh)
+{
+ struct gfs2_glock *gl = gh->gh_gl;
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ const struct gfs2_glock_operations *glops = gl->gl_ops;
+
+ if (test_bit(HIF_ABORTED, &gh->gh_iflags))
+ return -EIO;
+
+ if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
+ spin_lock(&gl->gl_spin);
+ if (gl->gl_req_gh != gh &&
+ !test_bit(HIF_HOLDER, &gh->gh_iflags) &&
+ !list_empty(&gh->gh_list)) {
+ list_del_init(&gh->gh_list);
+ gh->gh_error = GLR_TRYFAILED;
+ run_queue(gl);
+ spin_unlock(&gl->gl_spin);
+ return gh->gh_error;
+ }
+ spin_unlock(&gl->gl_spin);
+ }
+
+ if (gh->gh_flags & LM_FLAG_PRIORITY)
+ do_cancels(gh);
+
+ wait_on_holder(gh);
+ if (gh->gh_error)
+ return gh->gh_error;
+
+ gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags));
+ gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state,
+ gh->gh_flags));
+
+ if (test_bit(HIF_FIRST, &gh->gh_iflags)) {
+ gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
+
+ if (glops->go_lock) {
+ gh->gh_error = glops->go_lock(gh);
+ if (gh->gh_error) {
+ spin_lock(&gl->gl_spin);
+ list_del_init(&gh->gh_list);
+ spin_unlock(&gl->gl_spin);
+ }
+ }
+
+ spin_lock(&gl->gl_spin);
+ gl->gl_req_gh = NULL;
+ gl->gl_req_bh = NULL;
+ clear_bit(GLF_LOCK, &gl->gl_flags);
+ run_queue(gl);
+ spin_unlock(&gl->gl_spin);
+ }
+
+ return gh->gh_error;
+}
+
+static inline struct gfs2_holder *
+find_holder_by_owner(struct list_head *head, pid_t pid)
+{
+ struct gfs2_holder *gh;
+
+ list_for_each_entry(gh, head, gh_list) {
+ if (gh->gh_owner_pid == pid)
+ return gh;
+ }
+
+ return NULL;
+}
+
+static void print_dbg(struct glock_iter *gi, const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ if (gi) {
+ vsprintf(gi->string, fmt, args);
+ seq_printf(gi->seq, gi->string);
+ }
+ else
+ vprintk(fmt, args);
+ va_end(args);
+}
+
+/**
+ * add_to_queue - Add a holder to the wait queue (but look for recursion)
+ * @gh: the holder structure to add
+ *
+ */
+
+static void add_to_queue(struct gfs2_holder *gh)
+{
+ struct gfs2_glock *gl = gh->gh_gl;
+ struct gfs2_holder *existing;
+
+ BUG_ON(!gh->gh_owner_pid);
+ if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
+ BUG();
+
+ existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner_pid);
+ if (existing) {
+ print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);
+ printk(KERN_INFO "pid : %d\n", existing->gh_owner_pid);
+ printk(KERN_INFO "lock type : %d lock state : %d\n",
+ existing->gh_gl->gl_name.ln_type, existing->gh_gl->gl_state);
+ print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
+ printk(KERN_INFO "pid : %d\n", gh->gh_owner_pid);
+ printk(KERN_INFO "lock type : %d lock state : %d\n",
+ gl->gl_name.ln_type, gl->gl_state);
+ BUG();
+ }
+
+ existing = find_holder_by_owner(&gl->gl_waiters3, gh->gh_owner_pid);
+ if (existing) {
+ print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);
+ print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
+ BUG();
+ }
+
+ if (gh->gh_flags & LM_FLAG_PRIORITY)
+ list_add(&gh->gh_list, &gl->gl_waiters3);
+ else
+ list_add_tail(&gh->gh_list, &gl->gl_waiters3);
+}
+
+/**
+ * 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;
+
+restart:
+ if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
+ set_bit(HIF_ABORTED, &gh->gh_iflags);
+ return -EIO;
+ }
+
+ set_bit(HIF_PROMOTE, &gh->gh_iflags);
+
+ spin_lock(&gl->gl_spin);
+ add_to_queue(gh);
+ run_queue(gl);
+ spin_unlock(&gl->gl_spin);
+
+ if (!(gh->gh_flags & GL_ASYNC)) {
+ error = glock_wait_internal(gh);
+ if (error == GLR_CANCELED) {
+ msleep(100);
+ goto restart;
+ }
+ }
+
+ 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)
+{
+ struct gfs2_glock *gl = gh->gh_gl;
+ int ready = 0;
+
+ spin_lock(&gl->gl_spin);
+
+ if (test_bit(HIF_HOLDER, &gh->gh_iflags))
+ ready = 1;
+ else if (list_empty(&gh->gh_list)) {
+ if (gh->gh_error == GLR_CANCELED) {
+ spin_unlock(&gl->gl_spin);
+ msleep(100);
+ if (gfs2_glock_nq(gh))
+ return 1;
+ return 0;
+ } else
+ ready = 1;
+ }
+
+ spin_unlock(&gl->gl_spin);
+
+ return ready;
+}
+
+/**
+ * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
+ * @gh: the holder structure
+ *
+ * Returns: 0, GLR_TRYFAILED, or errno on failure
+ */
+
+int gfs2_glock_wait(struct gfs2_holder *gh)
+{
+ int error;
+
+ error = glock_wait_internal(gh);
+ if (error == GLR_CANCELED) {
+ msleep(100);
+ gh->gh_flags &= ~GL_ASYNC;
+ error = gfs2_glock_nq(gh);
+ }
+
+ return error;
+}
+
+/**
+ * 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;
+
+ if (gh->gh_flags & GL_NOCACHE)
+ handle_callback(gl, LM_ST_UNLOCKED);
+
+ gfs2_glmutex_lock(gl);
+
+ spin_lock(&gl->gl_spin);
+ list_del_init(&gh->gh_list);
+
+ if (list_empty(&gl->gl_holders)) {
+ spin_unlock(&gl->gl_spin);
+
+ if (glops->go_unlock)
+ glops->go_unlock(gh);
+
+ spin_lock(&gl->gl_spin);
+ gl->gl_stamp = jiffies;
+ }
+
+ clear_bit(GLF_LOCK, &gl->gl_flags);
+ run_queue(gl);
+ spin_unlock(&gl->gl_spin);
+}
+
+/**
+ * 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 aquisition
+ * @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
+ *
+ * Figure out how big an impact this function has. Either:
+ * 1) Replace this code with code that calls gfs2_glock_prefetch()
+ * 2) Forget async stuff and just call nq_m_sync()
+ * 3) Leave it like it is
+ *
+ * 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)
+{
+ int *e;
+ unsigned int x;
+ int borked = 0, serious = 0;
+ int error = 0;
+
+ if (!num_gh)
+ return 0;
+
+ if (num_gh == 1) {
+ ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
+ return gfs2_glock_nq(ghs);
+ }
+
+ e = kcalloc(num_gh, sizeof(struct gfs2_holder *), GFP_KERNEL);
+ if (!e)
+ return -ENOMEM;
+
+ for (x = 0; x < num_gh; x++) {
+ ghs[x].gh_flags |= LM_FLAG_TRY | GL_ASYNC;
+ error = gfs2_glock_nq(&ghs[x]);
+ if (error) {
+ borked = 1;
+ serious = error;
+ num_gh = x;
+ break;
+ }
+ }
+
+ for (x = 0; x < num_gh; x++) {
+ error = e[x] = glock_wait_internal(&ghs[x]);
+ if (error) {
+ borked = 1;
+ if (error != GLR_TRYFAILED && error != GLR_CANCELED)
+ serious = error;
+ }
+ }
+
+ if (!borked) {
+ kfree(e);
+ return 0;
+ }
+
+ for (x = 0; x < num_gh; x++)
+ if (!e[x])
+ gfs2_glock_dq(&ghs[x]);
+
+ if (serious)
+ error = serious;
+ else {
+ for (x = 0; x < num_gh; x++)
+ gfs2_holder_reinit(ghs[x].gh_state, ghs[x].gh_flags,
+ &ghs[x]);
+ error = nq_m_sync(num_gh, ghs, (struct gfs2_holder **)e);
+ }
+
+ kfree(e);
+
+ 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)
+{
+ unsigned int x;
+
+ for (x = 0; x < num_gh; x++)
+ gfs2_glock_dq(&ghs[x]);
+}
+
+/**
+ * gfs2_glock_dq_uninit_m - release multiple glocks
+ * @num_gh: the number of structures
+ * @ghs: an array of struct gfs2_holder structures
+ *
+ */
+
+void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
+{
+ unsigned int x;
+
+ for (x = 0; x < num_gh; x++)
+ gfs2_glock_dq_uninit(&ghs[x]);
+}
+
+/**
+ * gfs2_lvb_hold - attach a LVB from a glock
+ * @gl: The glock in question
+ *
+ */
+
+int gfs2_lvb_hold(struct gfs2_glock *gl)
+{
+ int error;
+
+ gfs2_glmutex_lock(gl);
+
+ if (!atomic_read(&gl->gl_lvb_count)) {
+ error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb);
+ if (error) {
+ gfs2_glmutex_unlock(gl);
+ return error;
+ }
+ gfs2_glock_hold(gl);
+ }
+ atomic_inc(&gl->gl_lvb_count);
+
+ gfs2_glmutex_unlock(gl);
+
+ return 0;
+}
+
+/**
+ * gfs2_lvb_unhold - detach a LVB from a glock
+ * @gl: The glock in question
+ *
+ */
+
+void gfs2_lvb_unhold(struct gfs2_glock *gl)
+{
+ gfs2_glock_hold(gl);
+ gfs2_glmutex_lock(gl);
+
+ gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0);
+ if (atomic_dec_and_test(&gl->gl_lvb_count)) {
+ gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb);
+ gl->gl_lvb = NULL;
+ gfs2_glock_put(gl);
+ }
+
+ gfs2_glmutex_unlock(gl);
+ gfs2_glock_put(gl);
+}
+
+static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
+ unsigned int state)
+{
+ struct gfs2_glock *gl;
+
+ gl = gfs2_glock_find(sdp, name);
+ if (!gl)
+ return;
+
+ handle_callback(gl, state);
+
+ spin_lock(&gl->gl_spin);
+ run_queue(gl);
+ spin_unlock(&gl->gl_spin);
+
+ gfs2_glock_put(gl);
+}
+
+/**
+ * gfs2_glock_cb - Callback used by locking module
+ * @sdp: Pointer to the superblock
+ * @type: Type of callback
+ * @data: Type dependent data pointer
+ *
+ * Called by the locking module when it wants to tell us something.
+ * Either we need to drop a lock, one of our ASYNC requests completed, or
+ * a journal from another client needs to be recovered.
+ */
+
+void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
+{
+ struct gfs2_sbd *sdp = cb_data;
+
+ switch (type) {
+ case LM_CB_NEED_E:
+ blocking_cb(sdp, data, LM_ST_UNLOCKED);
+ return;
+
+ case LM_CB_NEED_D:
+ blocking_cb(sdp, data, LM_ST_DEFERRED);
+ return;
+
+ case LM_CB_NEED_S:
+ blocking_cb(sdp, data, LM_ST_SHARED);
+ return;
+
+ case LM_CB_ASYNC: {
+ struct lm_async_cb *async = data;
+ struct gfs2_glock *gl;
+
+ down_read(&gfs2_umount_flush_sem);
+ gl = gfs2_glock_find(sdp, &async->lc_name);
+ if (gfs2_assert_warn(sdp, gl))
+ return;
+ if (!gfs2_assert_warn(sdp, gl->gl_req_bh))
+ gl->gl_req_bh(gl, async->lc_ret);
+ gfs2_glock_put(gl);
+ up_read(&gfs2_umount_flush_sem);
+ return;
+ }
+
+ case LM_CB_NEED_RECOVERY:
+ gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data);
+ if (sdp->sd_recoverd_process)
+ wake_up_process(sdp->sd_recoverd_process);
+ return;
+
+ case LM_CB_DROPLOCKS:
+ gfs2_gl_hash_clear(sdp, NO_WAIT);
+ gfs2_quota_scan(sdp);
+ return;
+
+ default:
+ gfs2_assert_warn(sdp, 0);
+ return;
+ }
+}
+
+/**
+ * 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(struct gfs2_glock *gl)
+{
+ const struct gfs2_glock_operations *glops = gl->gl_ops;
+ int demote = 1;
+
+ if (test_bit(GLF_STICKY, &gl->gl_flags))
+ demote = 0;
+ else if (glops->go_demote_ok)
+ demote = glops->go_demote_ok(gl);
+
+ return demote;
+}
+
+/**
+ * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
+ * @gl: the glock
+ *
+ */
+
+void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
+{
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+
+ spin_lock(&sdp->sd_reclaim_lock);
+ if (list_empty(&gl->gl_reclaim)) {
+ gfs2_glock_hold(gl);
+ list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list);
+ atomic_inc(&sdp->sd_reclaim_count);
+ }
+ spin_unlock(&sdp->sd_reclaim_lock);
+
+ wake_up(&sdp->sd_reclaim_wq);
+}
+
+/**
+ * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
+ * @sdp: the filesystem
+ *
+ * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
+ * different glock and we notice that there are a lot of glocks in the
+ * reclaim list.
+ *
+ */
+
+void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
+{
+ struct gfs2_glock *gl;
+
+ spin_lock(&sdp->sd_reclaim_lock);
+ if (list_empty(&sdp->sd_reclaim_list)) {
+ spin_unlock(&sdp->sd_reclaim_lock);
+ return;
+ }
+ gl = list_entry(sdp->sd_reclaim_list.next,
+ struct gfs2_glock, gl_reclaim);
+ list_del_init(&gl->gl_reclaim);
+ spin_unlock(&sdp->sd_reclaim_lock);
+
+ atomic_dec(&sdp->sd_reclaim_count);
+ atomic_inc(&sdp->sd_reclaimed);
+
+ if (gfs2_glmutex_trylock(gl)) {
+ if (list_empty(&gl->gl_holders) &&
+ gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
+ handle_callback(gl, LM_ST_UNLOCKED);
+ gfs2_glmutex_unlock(gl);
+ }
+
+ gfs2_glock_put(gl);
+}
+
+/**
+ * examine_bucket - Call a function for glock in a hash bucket
+ * @examiner: the function
+ * @sdp: the filesystem
+ * @bucket: the bucket
+ *
+ * Returns: 1 if the bucket has entries
+ */
+
+static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
+ unsigned int hash)
+{
+ struct gfs2_glock *gl, *prev = NULL;
+ int has_entries = 0;
+ struct hlist_head *head = &gl_hash_table[hash].hb_list;
+
+ read_lock(gl_lock_addr(hash));
+ /* Can't use hlist_for_each_entry - don't want prefetch here */
+ if (hlist_empty(head))
+ goto out;
+ gl = list_entry(head->first, struct gfs2_glock, gl_list);
+ while(1) {
+ if (gl->gl_sbd == sdp) {
+ gfs2_glock_hold(gl);
+ read_unlock(gl_lock_addr(hash));
+ if (prev)
+ gfs2_glock_put(prev);
+ prev = gl;
+ examiner(gl);
+ has_entries = 1;
+ read_lock(gl_lock_addr(hash));
+ }
+ if (gl->gl_list.next == NULL)
+ break;
+ gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
+ }
+out:
+ read_unlock(gl_lock_addr(hash));
+ if (prev)
+ gfs2_glock_put(prev);
+ return has_entries;
+}
+
+/**
+ * scan_glock - look at a glock and see if we can reclaim it
+ * @gl: the glock to look at
+ *
+ */
+
+static void scan_glock(struct gfs2_glock *gl)
+{
+ if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object)
+ return;
+
+ if (gfs2_glmutex_trylock(gl)) {
+ if (list_empty(&gl->gl_holders) &&
+ gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
+ goto out_schedule;
+ gfs2_glmutex_unlock(gl);
+ }
+ return;
+
+out_schedule:
+ gfs2_glmutex_unlock(gl);
+ gfs2_glock_schedule_for_reclaim(gl);
+}
+
+/**
+ * gfs2_scand_internal - Look for glocks and inodes to toss from memory
+ * @sdp: the filesystem
+ *
+ */
+
+void gfs2_scand_internal(struct gfs2_sbd *sdp)
+{
+ unsigned int x;
+
+ for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
+ examine_bucket(scan_glock, sdp, x);
+}
+
+/**
+ * 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)
+{
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ int released;
+
+ spin_lock(&sdp->sd_reclaim_lock);
+ if (!list_empty(&gl->gl_reclaim)) {
+ list_del_init(&gl->gl_reclaim);
+ atomic_dec(&sdp->sd_reclaim_count);
+ spin_unlock(&sdp->sd_reclaim_lock);
+ released = gfs2_glock_put(gl);
+ gfs2_assert(sdp, !released);
+ } else {
+ spin_unlock(&sdp->sd_reclaim_lock);
+ }
+
+ if (gfs2_glmutex_trylock(gl)) {
+ if (list_empty(&gl->gl_holders) &&
+ gl->gl_state != LM_ST_UNLOCKED)
+ handle_callback(gl, LM_ST_UNLOCKED);
+ gfs2_glmutex_unlock(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, or when inter-node lock manager
+ * requests DROPLOCKS because it is running out of capacity.
+ */
+
+void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait)
+{
+ unsigned long t;
+ unsigned int x;
+ int cont;
+
+ t = jiffies;
+
+ for (;;) {
+ cont = 0;
+ for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
+ if (examine_bucket(clear_glock, sdp, x))
+ cont = 1;
+ }
+
+ if (!wait || !cont)
+ break;
+
+ if (time_after_eq(jiffies,
+ t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
+ fs_warn(sdp, "Unmount seems to be stalled. "
+ "Dumping lock state...\n");
+ gfs2_dump_lockstate(sdp);
+ t = jiffies;
+ }
+
+ down_write(&gfs2_umount_flush_sem);
+ invalidate_inodes(sdp->sd_vfs);
+ up_write(&gfs2_umount_flush_sem);
+ msleep(10);
+ }
+}
+
+/*
+ * Diagnostic routines to help debug distributed deadlock
+ */
+
+static void gfs2_print_symbol(struct glock_iter *gi, const char *fmt,
+ unsigned long address)
+{
+/* when sprint_symbol becomes available in the new kernel, replace this */
+/* function with:
+ char buffer[KSYM_SYMBOL_LEN];
+
+ sprint_symbol(buffer, address);
+ print_dbg(gi, fmt, buffer);
+*/
+ if (gi)
+ print_dbg(gi, fmt, address);
+ else
+ print_symbol(fmt, address);
+}
+
+/**
+ * dump_holder - print information about a glock holder
+ * @str: a string naming the type of holder
+ * @gh: the glock holder
+ *
+ * Returns: 0 on success, -ENOBUFS when we run out of space
+ */
+
+static int dump_holder(struct glock_iter *gi, char *str,
+ struct gfs2_holder *gh)
+{
+ unsigned int x;
+ struct task_struct *gh_owner;
+
+ print_dbg(gi, " %s\n", str);
+ if (gh->gh_owner_pid) {
+ print_dbg(gi, " owner = %ld ", (long)gh->gh_owner_pid);
+ gh_owner = find_task_by_pid(gh->gh_owner_pid);
+ if (gh_owner)
+ print_dbg(gi, "(%s)\n", gh_owner->comm);
+ else
+ print_dbg(gi, "(ended)\n");
+ } else
+ print_dbg(gi, " owner = -1\n");
+ print_dbg(gi, " gh_state = %u\n", gh->gh_state);
+ print_dbg(gi, " gh_flags =");
+ for (x = 0; x < 32; x++)
+ if (gh->gh_flags & (1 << x))
+ print_dbg(gi, " %u", x);
+ print_dbg(gi, " \n");
+ print_dbg(gi, " error = %d\n", gh->gh_error);
+ print_dbg(gi, " gh_iflags =");
+ for (x = 0; x < 32; x++)
+ if (test_bit(x, &gh->gh_iflags))
+ print_dbg(gi, " %u", x);
+ print_dbg(gi, " \n");
+ gfs2_print_symbol(gi, " initialized at: %s\n", gh->gh_ip);
+
+ return 0;
+}
+
+/**
+ * dump_inode - print information about an inode
+ * @ip: the inode
+ *
+ * Returns: 0 on success, -ENOBUFS when we run out of space
+ */
+
+static int dump_inode(struct glock_iter *gi, struct gfs2_inode *ip)
+{
+ unsigned int x;
+
+ print_dbg(gi, " Inode:\n");
+ print_dbg(gi, " num = %llu/%llu\n",
+ ip->i_num.no_formal_ino, ip->i_num.no_addr);
+ print_dbg(gi, " type = %u\n", IF2DT(ip->i_inode.i_mode));
+ print_dbg(gi, " i_flags =");
+ for (x = 0; x < 32; x++)
+ if (test_bit(x, &ip->i_flags))
+ print_dbg(gi, " %u", x);
+ print_dbg(gi, " \n");
+ return 0;
+}
+
+/**
+ * dump_glock - print information about a glock
+ * @gl: the glock
+ * @count: where we are in the buffer
+ *
+ * Returns: 0 on success, -ENOBUFS when we run out of space
+ */
+
+static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl)
+{
+ struct gfs2_holder *gh;
+ unsigned int x;
+ int error = -ENOBUFS;
+ struct task_struct *gl_owner;
+
+ spin_lock(&gl->gl_spin);
+
+ print_dbg(gi, "Glock 0x%p (%u, %llu)\n", gl, gl->gl_name.ln_type,
+ (unsigned long long)gl->gl_name.ln_number);
+ print_dbg(gi, " gl_flags =");
+ for (x = 0; x < 32; x++) {
+ if (test_bit(x, &gl->gl_flags))
+ print_dbg(gi, " %u", x);
+ }
+ if (!test_bit(GLF_LOCK, &gl->gl_flags))
+ print_dbg(gi, " (unlocked)");
+ print_dbg(gi, " \n");
+ print_dbg(gi, " gl_ref = %d\n", atomic_read(&gl->gl_ref));
+ print_dbg(gi, " gl_state = %u\n", gl->gl_state);
+ if (gl->gl_owner_pid) {
+ gl_owner = find_task_by_pid(gl->gl_owner_pid);
+ if (gl_owner)
+ print_dbg(gi, " gl_owner = pid %d (%s)\n",
+ gl->gl_owner_pid, gl_owner->comm);
+ else
+ print_dbg(gi, " gl_owner = %d (ended)\n",
+ gl->gl_owner_pid);
+ } else
+ print_dbg(gi, " gl_owner = -1\n");
+ print_dbg(gi, " gl_ip = %lu\n", gl->gl_ip);
+ print_dbg(gi, " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no");
+ print_dbg(gi, " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no");
+ print_dbg(gi, " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count));
+ print_dbg(gi, " object = %s\n", (gl->gl_object) ? "yes" : "no");
+ print_dbg(gi, " le = %s\n",
+ (list_empty(&gl->gl_le.le_list)) ? "no" : "yes");
+ print_dbg(gi, " reclaim = %s\n",
+ (list_empty(&gl->gl_reclaim)) ? "no" : "yes");
+ if (gl->gl_aspace)
+ print_dbg(gi, " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace,
+ gl->gl_aspace->i_mapping->nrpages);
+ else
+ print_dbg(gi, " aspace = no\n");
+ print_dbg(gi, " ail = %d\n", atomic_read(&gl->gl_ail_count));
+ if (gl->gl_req_gh) {
+ error = dump_holder(gi, "Request", gl->gl_req_gh);
+ if (error)
+ goto out;
+ }
+ list_for_each_entry(gh, &gl->gl_holders, gh_list) {
+ error = dump_holder(gi, "Holder", gh);
+ if (error)
+ goto out;
+ }
+ list_for_each_entry(gh, &gl->gl_waiters1, gh_list) {
+ error = dump_holder(gi, "Waiter1", gh);
+ if (error)
+ goto out;
+ }
+ list_for_each_entry(gh, &gl->gl_waiters3, gh_list) {
+ error = dump_holder(gi, "Waiter3", gh);
+ if (error)
+ goto out;
+ }
+ if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
+ print_dbg(gi, " Demotion req to state %u (%llu uS ago)\n",
+ gl->gl_demote_state,
+ (u64)(jiffies - gl->gl_demote_time)*(1000000/HZ));
+ }
+ if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) {
+ if (!test_bit(GLF_LOCK, &gl->gl_flags) &&
+ list_empty(&gl->gl_holders)) {
+ error = dump_inode(gi, gl->gl_object);
+ if (error)
+ goto out;
+ } else {
+ error = -ENOBUFS;
+ print_dbg(gi, " Inode: busy\n");
+ }
+ }
+
+ error = 0;
+
+out:
+ spin_unlock(&gl->gl_spin);
+ return error;
+}
+
+/**
+ * gfs2_dump_lockstate - print out the current lockstate
+ * @sdp: the filesystem
+ * @ub: the buffer to copy the information into
+ *
+ * If @ub is NULL, dump the lockstate to the console.
+ *
+ */
+
+static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
+{
+ struct gfs2_glock *gl;
+ struct hlist_node *h;
+ unsigned int x;
+ int error = 0;
+
+ for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
+
+ read_lock(gl_lock_addr(x));
+
+ hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
+ if (gl->gl_sbd != sdp)
+ continue;
+
+ error = dump_glock(NULL, gl);
+ if (error)
+ break;
+ }
+
+ read_unlock(gl_lock_addr(x));
+
+ if (error)
+ break;
+ }
+
+
+ return error;
+}
+
+int __init gfs2_glock_init(void)
+{
+ unsigned i;
+ for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
+ INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
+ }
+#ifdef GL_HASH_LOCK_SZ
+ for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
+ rwlock_init(&gl_hash_locks[i]);
+ }
+#endif
+ return 0;
+}
+
+static int gfs2_glock_iter_next(struct glock_iter *gi)
+{
+ while (1) {
+ if (!gi->hb_list) { /* If we don't have a hash bucket yet */
+ gi->hb_list = &gl_hash_table[gi->hash].hb_list;
+ if (hlist_empty(gi->hb_list)) {
+ gi->hash++;
+ gi->hb_list = NULL;
+ if (gi->hash >= GFS2_GL_HASH_SIZE)
+ return 1;
+ else
+ continue;
+ }
+ if (!hlist_empty(gi->hb_list)) {
+ gi->gl = list_entry(gi->hb_list->first,
+ struct gfs2_glock,
+ gl_list);
+ }
+ } else {
+ if (gi->gl->gl_list.next == NULL) {
+ gi->hash++;
+ gi->hb_list = NULL;
+ continue;
+ }
+ gi->gl = list_entry(gi->gl->gl_list.next,
+ struct gfs2_glock, gl_list);
+ }
+ if (gi->gl)
+ break;
+ }
+ return 0;
+}
+
+static void gfs2_glock_iter_free(struct glock_iter *gi)
+{
+ kfree(gi);
+}
+
+static struct glock_iter *gfs2_glock_iter_init(struct gfs2_sbd *sdp)
+{
+ struct glock_iter *gi;
+
+ gi = kmalloc(sizeof (*gi), GFP_KERNEL);
+ if (!gi)
+ return NULL;
+
+ gi->sdp = sdp;
+ gi->hash = 0;
+ gi->gl = NULL;
+ gi->hb_list = NULL;
+ gi->seq = NULL;
+ memset(gi->string, 0, sizeof(gi->string));
+
+ if (gfs2_glock_iter_next(gi)) {
+ gfs2_glock_iter_free(gi);
+ return NULL;
+ }
+
+ return gi;
+}
+
+static void *gfs2_glock_seq_start(struct seq_file *file, loff_t *pos)
+{
+ struct glock_iter *gi;
+ loff_t n = *pos;
+
+ gi = gfs2_glock_iter_init(file->private);
+ if (!gi)
+ return NULL;
+
+ while (n--) {
+ if (gfs2_glock_iter_next(gi)) {
+ gfs2_glock_iter_free(gi);
+ return NULL;
+ }
+ }
+
+ return gi;
+}
+
+static void *gfs2_glock_seq_next(struct seq_file *file, void *iter_ptr,
+ loff_t *pos)
+{
+ struct glock_iter *gi = iter_ptr;
+
+ (*pos)++;
+
+ if (gfs2_glock_iter_next(gi)) {
+ gfs2_glock_iter_free(gi);
+ return NULL;
+ }
+
+ return gi;
+}
+
+static void gfs2_glock_seq_stop(struct seq_file *file, void *iter_ptr)
+{
+ /* nothing for now */
+}
+
+static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr)
+{
+ struct glock_iter *gi = iter_ptr;
+
+ gi->seq = file;
+ dump_glock(gi, gi->gl);
+
+ return 0;
+}
+
+static 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 int gfs2_debugfs_open(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq;
+ int ret;
+
+ ret = seq_open(file, &gfs2_glock_seq_ops);
+ if (ret)
+ return ret;
+
+ seq = file->private_data;
+ seq->private = inode->i_private;
+
+ return 0;
+}
+
+static const struct file_operations gfs2_debug_fops = {
+ .owner = THIS_MODULE,
+ .open = gfs2_debugfs_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release
+};
+
+int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
+{
+ sdp->debugfs_dentry = debugfs_create_file(sdp->sd_table_name,
+ S_IFREG | S_IRUGO,
+ gfs2_root, sdp,
+ &gfs2_debug_fops);
+ if (!sdp->debugfs_dentry)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
+{
+ if (sdp && sdp->debugfs_dentry)
+ debugfs_remove(sdp->debugfs_dentry);
+}
+
+int gfs2_register_debugfs(void)
+{
+ gfs2_root = debugfs_create_dir("gfs2", NULL);
+ return gfs2_root ? 0 : -ENOMEM;
+}
+
+void gfs2_unregister_debugfs(void)
+{
+ debugfs_remove(gfs2_root);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff