Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
 */
 
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/buffer_head.h>
#include <linux/delay.h>
#include <linux/sort.h>
#include <linux/hash.h>
#include <linux/jhash.h>
#include <linux/kallsyms.h>
#include <linux/gfs2_ondisk.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/workqueue.h>
#include <linux/jiffies.h>
#include <linux/rcupdate.h>
#include <linux/rculist_bl.h>
#include <linux/bit_spinlock.h>
#include <linux/percpu.h>
#include <linux/list_sort.h>
#include <linux/lockref.h>
#include <linux/rhashtable.h>
 
#include "gfs2.h"
#include "incore.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "lops.h"
#include "meta_io.h"
#include "quota.h"
#include "super.h"
#include "util.h"
#include "bmap.h"
#define CREATE_TRACE_POINTS
#include "trace_gfs2.h"
 
struct gfs2_glock_iter {
<------>struct gfs2_sbd *sdp;		/* incore superblock           */
<------>struct rhashtable_iter hti;	/* rhashtable iterator         */
<------>struct gfs2_glock *gl;		/* current glock struct        */
<------>loff_t last_pos;		/* last position               */
};
 
typedef void (*glock_examiner) (struct gfs2_glock * gl);
 
static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
 
static struct dentry *gfs2_root;
static struct workqueue_struct *glock_workqueue;
struct workqueue_struct *gfs2_delete_workqueue;
static LIST_HEAD(lru_list);
static atomic_t lru_count = ATOMIC_INIT(0);
static DEFINE_SPINLOCK(lru_lock);
 
#define GFS2_GL_HASH_SHIFT      15
#define GFS2_GL_HASH_SIZE       BIT(GFS2_GL_HASH_SHIFT)
 
static const struct rhashtable_params ht_parms = {
<------>.nelem_hint = GFS2_GL_HASH_SIZE * 3 / 4,
<------>.key_len = offsetofend(struct lm_lockname, ln_type),
<------>.key_offset = offsetof(struct gfs2_glock, gl_name),
<------>.head_offset = offsetof(struct gfs2_glock, gl_node),
};
 
static struct rhashtable gl_hash_table;
 
#define GLOCK_WAIT_TABLE_BITS 12
#define GLOCK_WAIT_TABLE_SIZE (1 << GLOCK_WAIT_TABLE_BITS)
static wait_queue_head_t glock_wait_table[GLOCK_WAIT_TABLE_SIZE] __cacheline_aligned;
 
struct wait_glock_queue {
<------>struct lm_lockname *name;
<------>wait_queue_entry_t wait;
};
 
static int glock_wake_function(wait_queue_entry_t *wait, unsigned int mode,
<------><------><------>       int sync, void *key)
{
<------>struct wait_glock_queue *wait_glock =
<------><------>container_of(wait, struct wait_glock_queue, wait);
<------>struct lm_lockname *wait_name = wait_glock->name;
<------>struct lm_lockname *wake_name = key;
 
<------>if (wake_name->ln_sbd != wait_name->ln_sbd ||
<------>    wake_name->ln_number != wait_name->ln_number ||
<------>    wake_name->ln_type != wait_name->ln_type)
<------><------>return 0;
<------>return autoremove_wake_function(wait, mode, sync, key);
}
 
static wait_queue_head_t *glock_waitqueue(struct lm_lockname *name)
{
<------>u32 hash = jhash2((u32 *)name, ht_parms.key_len / 4, 0);
 
<------>return glock_wait_table + hash_32(hash, GLOCK_WAIT_TABLE_BITS);
}
 
/**
 * wake_up_glock  -  Wake up waiters on a glock
 * @gl: the glock
 */
static void wake_up_glock(struct gfs2_glock *gl)
{
<------>wait_queue_head_t *wq = glock_waitqueue(&gl->gl_name);
 
<------>if (waitqueue_active(wq))
<------><------>__wake_up(wq, TASK_NORMAL, 1, &gl->gl_name);
}
 
static void gfs2_glock_dealloc(struct rcu_head *rcu)
{
<------>struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
 
<------>kfree(gl->gl_lksb.sb_lvbptr);
<------>if (gl->gl_ops->go_flags & GLOF_ASPACE)
<------><------>kmem_cache_free(gfs2_glock_aspace_cachep, gl);
<------>else
<------><------>kmem_cache_free(gfs2_glock_cachep, gl);
}
 
/**
 * glock_blocked_by_withdraw - determine if we can still use a glock
 * @gl: the glock
 *
 * We need to allow some glocks to be enqueued, dequeued, promoted, and demoted
 * when we're withdrawn. For example, to maintain metadata integrity, we should
 * disallow the use of inode and rgrp glocks when withdrawn. Other glocks, like
 * iopen or the transaction glocks may be safely used because none of their
 * metadata goes through the journal. So in general, we should disallow all
 * glocks that are journaled, and allow all the others. One exception is:
 * we need to allow our active journal to be promoted and demoted so others
 * may recover it and we can reacquire it when they're done.
 */
static bool glock_blocked_by_withdraw(struct gfs2_glock *gl)
{
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 
<------>if (likely(!gfs2_withdrawn(sdp)))
<------><------>return false;
<------>if (gl->gl_ops->go_flags & GLOF_NONDISK)
<------><------>return false;
<------>if (!sdp->sd_jdesc ||
<------>    gl->gl_name.ln_number == sdp->sd_jdesc->jd_no_addr)
<------><------>return false;
<------>return true;
}
 
void gfs2_glock_free(struct gfs2_glock *gl)
{
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 
<------>gfs2_glock_assert_withdraw(gl, atomic_read(&gl->gl_revokes) == 0);
<------>rhashtable_remove_fast(&gl_hash_table, &gl->gl_node, ht_parms);
<------>smp_mb();
<------>wake_up_glock(gl);
<------>call_rcu(&gl->gl_rcu, gfs2_glock_dealloc);
<------>if (atomic_dec_and_test(&sdp->sd_glock_disposal))
<------><------>wake_up(&sdp->sd_glock_wait);
}
 
/**
 * gfs2_glock_hold() - increment reference count on glock
 * @gl: The glock to hold
 *
 */
 
void gfs2_glock_hold(struct gfs2_glock *gl)
{
<------>GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
<------>lockref_get(&gl->gl_lockref);
}
 
/**
 * demote_ok - Check to see if it's ok to unlock a glock
 * @gl: the glock
 *
 * Returns: 1 if it's ok
 */
 
static int demote_ok(const struct gfs2_glock *gl)
{
<------>const struct gfs2_glock_operations *glops = gl->gl_ops;
 
<------>if (gl->gl_state == LM_ST_UNLOCKED)
<------><------>return 0;
<------>if (!list_empty(&gl->gl_holders))
<------><------>return 0;
<------>if (glops->go_demote_ok)
<------><------>return glops->go_demote_ok(gl);
<------>return 1;
}
 
 
void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
{
<------>if (!(gl->gl_ops->go_flags & GLOF_LRU))
<------><------>return;
 
<------>spin_lock(&lru_lock);
 
<------>list_del(&gl->gl_lru);
<------>list_add_tail(&gl->gl_lru, &lru_list);
 
<------>if (!test_bit(GLF_LRU, &gl->gl_flags)) {
<------><------>set_bit(GLF_LRU, &gl->gl_flags);
<------><------>atomic_inc(&lru_count);
<------>}
 
<------>spin_unlock(&lru_lock);
}
 
static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
{
<------>if (!(gl->gl_ops->go_flags & GLOF_LRU))
<------><------>return;
 
<------>spin_lock(&lru_lock);
<------>if (test_bit(GLF_LRU, &gl->gl_flags)) {
<------><------>list_del_init(&gl->gl_lru);
<------><------>atomic_dec(&lru_count);
<------><------>clear_bit(GLF_LRU, &gl->gl_flags);
<------>}
<------>spin_unlock(&lru_lock);
}
 
/*
 * Enqueue the glock on the work queue.  Passes one glock reference on to the
 * work queue.
 */
static void __gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) {
<------>if (!queue_delayed_work(glock_workqueue, &gl->gl_work, delay)) {
<------><------>/*
<------><------> * We are holding the lockref spinlock, and the work was still
<------><------> * queued above.  The queued work (glock_work_func) takes that
<------><------> * spinlock before dropping its glock reference(s), so it
<------><------> * cannot have dropped them in the meantime.
<------><------> */
<------><------>GLOCK_BUG_ON(gl, gl->gl_lockref.count < 2);
<------><------>gl->gl_lockref.count--;
<------>}
}
 
static void gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) {
<------>spin_lock(&gl->gl_lockref.lock);
<------>__gfs2_glock_queue_work(gl, delay);
<------>spin_unlock(&gl->gl_lockref.lock);
}
 
static void __gfs2_glock_put(struct gfs2_glock *gl)
{
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
<------>struct address_space *mapping = gfs2_glock2aspace(gl);
 
<------>lockref_mark_dead(&gl->gl_lockref);
 
<------>gfs2_glock_remove_from_lru(gl);
<------>spin_unlock(&gl->gl_lockref.lock);
<------>GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
<------>if (mapping) {
<------><------>truncate_inode_pages_final(mapping);
<------><------>if (!gfs2_withdrawn(sdp))
<------><------><------>GLOCK_BUG_ON(gl, mapping->nrpages ||
<------><------><------><------>     mapping->nrexceptional);
<------>}
<------>trace_gfs2_glock_put(gl);
<------>sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
}
 
/*
 * Cause the glock to be put in work queue context.
 */
void gfs2_glock_queue_put(struct gfs2_glock *gl)
{
<------>gfs2_glock_queue_work(gl, 0);
}
 
/**
 * gfs2_glock_put() - Decrement reference count on glock
 * @gl: The glock to put
 *
 */
 
void gfs2_glock_put(struct gfs2_glock *gl)
{
<------>if (lockref_put_or_lock(&gl->gl_lockref))
<------><------>return;
 
<------>__gfs2_glock_put(gl);
}
 
/**
 * may_grant - check if 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_first_entry(&gl->gl_holders, 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);
<------>if (gh->gh_flags & GL_ASYNC) {
<------><------>struct gfs2_sbd *sdp = gh->gh_gl->gl_name.ln_sbd;
 
<------><------>wake_up(&sdp->sd_async_glock_wait);
<------>}
}
 
/**
 * do_error - Something unexpected has happened during a lock request
 *
 */
 
static void do_error(struct gfs2_glock *gl, const int ret)
{
<------>struct gfs2_holder *gh, *tmp;
 
<------>list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
<------><------>if (test_bit(HIF_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_lockref.lock)
__acquires(&gl->gl_lockref.lock)
{
<------>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_lockref.lock);
<------><------><------><------>/* FIXME: eliminate this eventually */
<------><------><------><------>ret = glops->go_lock(gh);
<------><------><------><------>spin_lock(&gl->gl_lockref.lock);
<------><------><------><------>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 (new_state != gl->gl_target)
<------><------>/* shorten our minimum hold time */
<------><------>gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR,
<------><------><------><------>       GL_GLOCK_MIN_HOLD);
<------>gl->gl_state = new_state;
<------>gl->gl_tchange = jiffies;
}
 
static void gfs2_set_demote(struct gfs2_glock *gl)
{
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 
<------>set_bit(GLF_DEMOTE, &gl->gl_flags);
<------>smp_mb();
<------>wake_up(&sdp->sd_async_glock_wait);
}
 
static void gfs2_demote_wake(struct gfs2_glock *gl)
{
<------>gl->gl_demote_state = LM_ST_EXCLUSIVE;
<------>clear_bit(GLF_DEMOTE, &gl->gl_flags);
<------>smp_mb__after_atomic();
<------>wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
}
 
/**
 * finish_xmote - The DLM has replied to one of our lock requests
 * @gl: The glock
 * @ret: The status from the DLM
 *
 */
 
static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
{
<------>const struct gfs2_glock_operations *glops = gl->gl_ops;
<------>struct gfs2_holder *gh;
<------>unsigned state = ret & LM_OUT_ST_MASK;
<------>int rv;
 
<------>spin_lock(&gl->gl_lockref.lock);
<------>trace_gfs2_glock_state_change(gl, state);
<------>state_change(gl, state);
<------>gh = find_first_waiter(gl);
 
<------>/* Demote to UN request arrived during demote to SH or DF */
<------>if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
<------>    state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
<------><------>gl->gl_target = LM_ST_UNLOCKED;
 
<------>/* Check for state != intended state */
<------>if (unlikely(state != gl->gl_target)) {
<------><------>if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
<------><------><------>/* move to back of queue and try next entry */
<------><------><------>if (ret & LM_OUT_CANCELED) {
<------><------><------><------>if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
<------><------><------><------><------>list_move_tail(&gh->gh_list, &gl->gl_holders);
<------><------><------><------>gh = find_first_waiter(gl);
<------><------><------><------>gl->gl_target = gh->gh_state;
<------><------><------><------>goto retry;
<------><------><------>}
<------><------><------>/* Some error or failed "try lock" - report it */
<------><------><------>if ((ret & LM_OUT_ERROR) ||
<------><------><------>    (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
<------><------><------><------>gl->gl_target = gl->gl_state;
<------><------><------><------>do_error(gl, ret);
<------><------><------><------>goto out;
<------><------><------>}
<------><------>}
<------><------>switch(state) {
<------><------>/* Unlocked due to conversion deadlock, try again */
<------><------>case LM_ST_UNLOCKED:
retry:
<------><------><------>do_xmote(gl, gh, gl->gl_target);
<------><------><------>break;
<------><------>/* Conversion fails, unlock and try again */
<------><------>case LM_ST_SHARED:
<------><------>case LM_ST_DEFERRED:
<------><------><------>do_xmote(gl, gh, LM_ST_UNLOCKED);
<------><------><------>break;
<------><------>default: /* Everything else */
<------><------><------>fs_err(gl->gl_name.ln_sbd, "wanted %u got %u\n",
<------><------><------>       gl->gl_target, state);
<------><------><------>GLOCK_BUG_ON(gl, 1);
<------><------>}
<------><------>spin_unlock(&gl->gl_lockref.lock);
<------><------>return;
<------>}
 
<------>/* Fast path - we got what we asked for */
<------>if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
<------><------>gfs2_demote_wake(gl);
<------>if (state != LM_ST_UNLOCKED) {
<------><------>if (glops->go_xmote_bh) {
<------><------><------>spin_unlock(&gl->gl_lockref.lock);
<------><------><------>rv = glops->go_xmote_bh(gl, gh);
<------><------><------>spin_lock(&gl->gl_lockref.lock);
<------><------><------>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_lockref.lock);
}
 
static bool is_system_glock(struct gfs2_glock *gl)
{
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
<------>struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 
<------>if (gl == m_ip->i_gl)
<------><------>return true;
<------>return false;
}
 
/**
 * do_xmote - Calls the DLM to change the state of a lock
 * @gl: The lock state
 * @gh: The holder (only for promotes)
 * @target: The target lock state
 *
 */
 
static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
__releases(&gl->gl_lockref.lock)
__acquires(&gl->gl_lockref.lock)
{
<------>const struct gfs2_glock_operations *glops = gl->gl_ops;
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
<------>unsigned int lck_flags = (unsigned int)(gh ? gh->gh_flags : 0);
<------>int ret;
 
<------>if (target != LM_ST_UNLOCKED && glock_blocked_by_withdraw(gl) &&
<------>    gh && !(gh->gh_flags & LM_FLAG_NOEXP))
<------><------>return;
<------>lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
<------><------>      LM_FLAG_PRIORITY);
<------>GLOCK_BUG_ON(gl, gl->gl_state == target);
<------>GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);
<------>if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
<------>    glops->go_inval) {
<------><------>/*
<------><------> * If another process is already doing the invalidate, let that
<------><------> * finish first.  The glock state machine will get back to this
<------><------> * holder again later.
<------><------> */
<------><------>if (test_and_set_bit(GLF_INVALIDATE_IN_PROGRESS,
<------><------><------><------>     &gl->gl_flags))
<------><------><------>return;
<------><------>do_error(gl, 0); /* Fail queued try locks */
<------>}
<------>gl->gl_req = target;
<------>set_bit(GLF_BLOCKING, &gl->gl_flags);
<------>if ((gl->gl_req == LM_ST_UNLOCKED) ||
<------>    (gl->gl_state == LM_ST_EXCLUSIVE) ||
<------>    (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB)))
<------><------>clear_bit(GLF_BLOCKING, &gl->gl_flags);
<------>spin_unlock(&gl->gl_lockref.lock);
<------>if (glops->go_sync) {
<------><------>ret = glops->go_sync(gl);
<------><------>/* If we had a problem syncing (due to io errors or whatever,
<------><------> * we should not invalidate the metadata or tell dlm to
<------><------> * release the glock to other nodes.
<------><------> */
<------><------>if (ret) {
<------><------><------>if (cmpxchg(&sdp->sd_log_error, 0, ret)) {
<------><------><------><------>fs_err(sdp, "Error %d syncing glock \n", ret);
<------><------><------><------>gfs2_dump_glock(NULL, gl, true);
<------><------><------>}
<------><------><------>goto skip_inval;
<------><------>}
<------>}
<------>if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) {
<------><------>/*
<------><------> * The call to go_sync should have cleared out the ail list.
<------><------> * If there are still items, we have a problem. We ought to
<------><------> * withdraw, but we can't because the withdraw code also uses
<------><------> * glocks. Warn about the error, dump the glock, then fall
<------><------> * through and wait for logd to do the withdraw for us.
<------><------> */
<------><------>if ((atomic_read(&gl->gl_ail_count) != 0) &&
<------><------>    (!cmpxchg(&sdp->sd_log_error, 0, -EIO))) {
<------><------><------>gfs2_glock_assert_warn(gl,
<------><------><------><------><------>       !atomic_read(&gl->gl_ail_count));
<------><------><------>gfs2_dump_glock(NULL, gl, true);
<------><------>}
<------><------>glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
<------><------>clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
<------>}
 
skip_inval:
<------>gfs2_glock_hold(gl);
<------>/*
<------> * Check for an error encountered since we called go_sync and go_inval.
<------> * If so, we can't withdraw from the glock code because the withdraw
<------> * code itself uses glocks (see function signal_our_withdraw) to
<------> * change the mount to read-only. Most importantly, we must not call
<------> * dlm to unlock the glock until the journal is in a known good state
<------> * (after journal replay) otherwise other nodes may use the object
<------> * (rgrp or dinode) and then later, journal replay will corrupt the
<------> * file system. The best we can do here is wait for the logd daemon
<------> * to see sd_log_error and withdraw, and in the meantime, requeue the
<------> * work for later.
<------> *
<------> * We make a special exception for some system glocks, such as the
<------> * system statfs inode glock, which needs to be granted before the
<------> * gfs2_quotad daemon can exit, and that exit needs to finish before
<------> * we can unmount the withdrawn file system.
<------> *
<------> * However, if we're just unlocking the lock (say, for unmount, when
<------> * gfs2_gl_hash_clear calls clear_glock) and recovery is complete
<------> * then it's okay to tell dlm to unlock it.
<------> */
<------>if (unlikely(sdp->sd_log_error && !gfs2_withdrawn(sdp)))
<------><------>gfs2_withdraw_delayed(sdp);
<------>if (glock_blocked_by_withdraw(gl) &&
<------>    (target != LM_ST_UNLOCKED ||
<------>     test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags))) {
<------><------>if (!is_system_glock(gl)) {
<------><------><------>gfs2_glock_queue_work(gl, GL_GLOCK_DFT_HOLD);
<------><------><------>goto out;
<------><------>} else {
<------><------><------>clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
<------><------>}
<------>}
 
<------>if (sdp->sd_lockstruct.ls_ops->lm_lock)	{
<------><------>/* lock_dlm */
<------><------>ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
<------><------>if (ret == -EINVAL && gl->gl_target == LM_ST_UNLOCKED &&
<------><------>    target == LM_ST_UNLOCKED &&
<------><------>    test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags)) {
<------><------><------>finish_xmote(gl, target);
<------><------><------>gfs2_glock_queue_work(gl, 0);
<------><------>} else if (ret) {
<------><------><------>fs_err(sdp, "lm_lock ret %d\n", ret);
<------><------><------>GLOCK_BUG_ON(gl, !gfs2_withdrawn(sdp));
<------><------>}
<------>} else { /* lock_nolock */
<------><------>finish_xmote(gl, target);
<------><------>gfs2_glock_queue_work(gl, 0);
<------>}
out:
<------>spin_lock(&gl->gl_lockref.lock);
}
 
/**
 * find_first_holder - find the first "holder" gh
 * @gl: the glock
 */
 
static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
{
<------>struct gfs2_holder *gh;
 
<------>if (!list_empty(&gl->gl_holders)) {
<------><------>gh = list_first_entry(&gl->gl_holders, struct gfs2_holder, gh_list);
<------><------>if (test_bit(HIF_HOLDER, &gh->gh_iflags))
<------><------><------>return gh;
<------>}
<------>return NULL;
}
 
/**
 * run_queue - do all outstanding tasks related to a glock
 * @gl: The glock in question
 * @nonblock: True if we must not block in run_queue
 *
 */
 
static void run_queue(struct gfs2_glock *gl, const int nonblock)
__releases(&gl->gl_lockref.lock)
__acquires(&gl->gl_lockref.lock)
{
<------>struct gfs2_holder *gh = NULL;
<------>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++;
<------>__gfs2_glock_queue_work(gl, 0);
<------>return;
 
out_unlock:
<------>clear_bit(GLF_LOCK, &gl->gl_flags);
<------>smp_mb__after_atomic();
<------>return;
}
 
void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation)
{
<------>struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr;
 
<------>if (ri->ri_magic == 0)
<------><------>ri->ri_magic = cpu_to_be32(GFS2_MAGIC);
<------>if (ri->ri_magic == cpu_to_be32(GFS2_MAGIC))
<------><------>ri->ri_generation_deleted = cpu_to_be64(generation);
}
 
bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation)
{
<------>struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr;
 
<------>if (ri->ri_magic != cpu_to_be32(GFS2_MAGIC))
<------><------>return false;
<------>return generation <= be64_to_cpu(ri->ri_generation_deleted);
}
 
static void gfs2_glock_poke(struct gfs2_glock *gl)
{
<------>int flags = LM_FLAG_TRY_1CB | LM_FLAG_ANY | GL_SKIP;
<------>struct gfs2_holder gh;
<------>int error;
 
<------>gfs2_holder_init(gl, LM_ST_SHARED, flags, &gh);
<------>error = gfs2_glock_nq(&gh);
<------>if (!error)
<------><------>gfs2_glock_dq(&gh);
<------>gfs2_holder_uninit(&gh);
}
 
static bool gfs2_try_evict(struct gfs2_glock *gl)
{
<------>struct gfs2_inode *ip;
<------>bool evicted = false;
 
<------>/*
<------> * If there is contention on the iopen glock and we have an inode, try
<------> * to grab and release the inode so that it can be evicted.  This will
<------> * allow the remote node to go ahead and delete the inode without us
<------> * having to do it, which will avoid rgrp glock thrashing.
<------> *
<------> * The remote node is likely still holding the corresponding inode
<------> * glock, so it will run before we get to verify that the delete has
<------> * happened below.
<------> */
<------>spin_lock(&gl->gl_lockref.lock);
<------>ip = gl->gl_object;
<------>if (ip && !igrab(&ip->i_inode))
<------><------>ip = NULL;
<------>spin_unlock(&gl->gl_lockref.lock);
<------>if (ip) {
<------><------>struct gfs2_glock *inode_gl = NULL;
 
<------><------>gl->gl_no_formal_ino = ip->i_no_formal_ino;
<------><------>set_bit(GIF_DEFERRED_DELETE, &ip->i_flags);
<------><------>d_prune_aliases(&ip->i_inode);
<------><------>iput(&ip->i_inode);
 
<------><------>/* If the inode was evicted, gl->gl_object will now be NULL. */
<------><------>spin_lock(&gl->gl_lockref.lock);
<------><------>ip = gl->gl_object;
<------><------>if (ip) {
<------><------><------>inode_gl = ip->i_gl;
<------><------><------>lockref_get(&inode_gl->gl_lockref);
<------><------><------>clear_bit(GIF_DEFERRED_DELETE, &ip->i_flags);
<------><------>}
<------><------>spin_unlock(&gl->gl_lockref.lock);
<------><------>if (inode_gl) {
<------><------><------>gfs2_glock_poke(inode_gl);
<------><------><------>gfs2_glock_put(inode_gl);
<------><------>}
<------><------>evicted = !ip;
<------>}
<------>return evicted;
}
 
static void delete_work_func(struct work_struct *work)
{
<------>struct delayed_work *dwork = to_delayed_work(work);
<------>struct gfs2_glock *gl = container_of(dwork, struct gfs2_glock, gl_delete);
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
<------>struct inode *inode;
<------>u64 no_addr = gl->gl_name.ln_number;
 
<------>spin_lock(&gl->gl_lockref.lock);
<------>clear_bit(GLF_PENDING_DELETE, &gl->gl_flags);
<------>spin_unlock(&gl->gl_lockref.lock);
 
<------>/* If someone's using this glock to create a new dinode, the block must
<------>   have been freed by another node, then re-used, in which case our
<------>   iopen callback is too late after the fact. Ignore it. */
<------>if (test_bit(GLF_INODE_CREATING, &gl->gl_flags))
<------><------>goto out;
 
<------>if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
<------><------>/*
<------><------> * If we can evict the inode, give the remote node trying to
<------><------> * delete the inode some time before verifying that the delete
<------><------> * has happened.  Otherwise, if we cause contention on the inode glock
<------><------> * immediately, the remote node will think that we still have
<------><------> * the inode in use, and so it will give up waiting.
<------><------> *
<------><------> * If we can't evict the inode, signal to the remote node that
<------><------> * the inode is still in use.  We'll later try to delete the
<------><------> * inode locally in gfs2_evict_inode.
<------><------> *
<------><------> * FIXME: We only need to verify that the remote node has
<------><------> * deleted the inode because nodes before this remote delete
<------><------> * rework won't cooperate.  At a later time, when we no longer
<------><------> * care about compatibility with such nodes, we can skip this
<------><------> * step entirely.
<------><------> */
<------><------>if (gfs2_try_evict(gl)) {
<------><------><------>if (gfs2_queue_delete_work(gl, 5 * HZ))
<------><------><------><------>return;
<------><------>}
<------><------>goto out;
<------>}
 
<------>inode = gfs2_lookup_by_inum(sdp, no_addr, gl->gl_no_formal_ino,
<------><------><------><------>    GFS2_BLKST_UNLINKED);
<------>if (!IS_ERR_OR_NULL(inode)) {
<------><------>d_prune_aliases(inode);
<------><------>iput(inode);
<------>}
out:
<------>gfs2_glock_put(gl);
}
 
static void glock_work_func(struct work_struct *work)
{
<------>unsigned long delay = 0;
<------>struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
<------>unsigned int drop_refs = 1;
 
<------>if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
<------><------>finish_xmote(gl, gl->gl_reply);
<------><------>drop_refs++;
<------>}
<------>spin_lock(&gl->gl_lockref.lock);
<------>if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
<------>    gl->gl_state != LM_ST_UNLOCKED &&
<------>    gl->gl_demote_state != LM_ST_EXCLUSIVE) {
<------><------>unsigned long holdtime, now = jiffies;
 
<------><------>holdtime = gl->gl_tchange + gl->gl_hold_time;
<------><------>if (time_before(now, holdtime))
<------><------><------>delay = holdtime - now;
 
<------><------>if (!delay) {
<------><------><------>clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
<------><------><------>gfs2_set_demote(gl);
<------><------>}
<------>}
<------>run_queue(gl, 0);
<------>if (delay) {
<------><------>/* Keep one glock reference for the work we requeue. */
<------><------>drop_refs--;
<------><------>if (gl->gl_name.ln_type != LM_TYPE_INODE)
<------><------><------>delay = 0;
<------><------>__gfs2_glock_queue_work(gl, delay);
<------>}
 
<------>/*
<------> * Drop the remaining glock references manually here. (Mind that
<------> * __gfs2_glock_queue_work depends on the lockref spinlock begin held
<------> * here as well.)
<------> */
<------>gl->gl_lockref.count -= drop_refs;
<------>if (!gl->gl_lockref.count) {
<------><------>__gfs2_glock_put(gl);
<------><------>return;
<------>}
<------>spin_unlock(&gl->gl_lockref.lock);
}
 
static struct gfs2_glock *find_insert_glock(struct lm_lockname *name,
<------><------><------><------><------>    struct gfs2_glock *new)
{
<------>struct wait_glock_queue wait;
<------>wait_queue_head_t *wq = glock_waitqueue(name);
<------>struct gfs2_glock *gl;
 
<------>wait.name = name;
<------>init_wait(&wait.wait);
<------>wait.wait.func = glock_wake_function;
 
again:
<------>prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
<------>rcu_read_lock();
<------>if (new) {
<------><------>gl = rhashtable_lookup_get_insert_fast(&gl_hash_table,
<------><------><------>&new->gl_node, ht_parms);
<------><------>if (IS_ERR(gl))
<------><------><------>goto out;
<------>} else {
<------><------>gl = rhashtable_lookup_fast(&gl_hash_table,
<------><------><------>name, ht_parms);
<------>}
<------>if (gl && !lockref_get_not_dead(&gl->gl_lockref)) {
<------><------>rcu_read_unlock();
<------><------>schedule();
<------><------>goto again;
<------>}
out:
<------>rcu_read_unlock();
<------>finish_wait(wq, &wait.wait);
<------>return gl;
}
 
/**
 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
 * @sdp: The GFS2 superblock
 * @number: the lock number
 * @glops: The glock_operations to use
 * @create: If 0, don't create the glock if it doesn't exist
 * @glp: the glock is returned here
 *
 * This does not lock a glock, just finds/creates structures for one.
 *
 * Returns: errno
 */
 
int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
<------><------>   const struct gfs2_glock_operations *glops, int create,
<------><------>   struct gfs2_glock **glp)
{
<------>struct super_block *s = sdp->sd_vfs;
<------>struct lm_lockname name = { .ln_number = number,
<------><------><------><------>    .ln_type = glops->go_type,
<------><------><------><------>    .ln_sbd = sdp };
<------>struct gfs2_glock *gl, *tmp;
<------>struct address_space *mapping;
<------>struct kmem_cache *cachep;
<------>int ret = 0;
 
<------>gl = find_insert_glock(&name, NULL);
<------>if (gl) {
<------><------>*glp = gl;
<------><------>return 0;
<------>}
<------>if (!create)
<------><------>return -ENOENT;
 
<------>if (glops->go_flags & GLOF_ASPACE)
<------><------>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(GDLM_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_node.next = NULL;
<------>gl->gl_flags = 0;
<------>gl->gl_name = name;
<------>lockdep_set_subclass(&gl->gl_lockref.lock, glops->go_subclass);
<------>gl->gl_lockref.count = 1;
<------>gl->gl_state = LM_ST_UNLOCKED;
<------>gl->gl_target = LM_ST_UNLOCKED;
<------>gl->gl_demote_state = LM_ST_EXCLUSIVE;
<------>gl->gl_ops = glops;
<------>gl->gl_dstamp = 0;
<------>preempt_disable();
<------>/* We use the global stats to estimate the initial per-glock stats */
<------>gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type];
<------>preempt_enable();
<------>gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0;
<------>gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0;
<------>gl->gl_tchange = jiffies;
<------>gl->gl_object = NULL;
<------>gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
<------>INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
<------>if (gl->gl_name.ln_type == LM_TYPE_IOPEN)
<------><------>INIT_DELAYED_WORK(&gl->gl_delete, delete_work_func);
 
<------>mapping = gfs2_glock2aspace(gl);
<------>if (mapping) {
                mapping->a_ops = &gfs2_meta_aops;
<------><------>mapping->host = s->s_bdev->bd_inode;
<------><------>mapping->flags = 0;
<------><------>mapping_set_gfp_mask(mapping, GFP_NOFS);
<------><------>mapping->private_data = NULL;
<------><------>mapping->writeback_index = 0;
<------>}
 
<------>tmp = find_insert_glock(&name, gl);
<------>if (!tmp) {
<------><------>*glp = gl;
<------><------>goto out;
<------>}
<------>if (IS_ERR(tmp)) {
<------><------>ret = PTR_ERR(tmp);
<------><------>goto out_free;
<------>}
<------>*glp = tmp;
 
out_free:
<------>kfree(gl->gl_lksb.sb_lvbptr);
<------>kmem_cache_free(cachep, gl);
<------>if (atomic_dec_and_test(&sdp->sd_glock_disposal))
<------><------>wake_up(&sdp->sd_glock_wait);
 
out:
<------>return ret;
}
 
/**
 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
 * @gl: the glock
 * @state: the state we're requesting
 * @flags: the modifier flags
 * @gh: the holder structure
 *
 */
 
void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, u16 flags,
<------><------>      struct gfs2_holder *gh)
{
<------>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, u16 flags, struct gfs2_holder *gh)
{
<------>gh->gh_state = state;
<------>gh->gh_flags = flags;
<------>gh->gh_iflags = 0;
<------>gh->gh_ip = _RET_IP_;
<------>put_pid(gh->gh_owner_pid);
<------>gh->gh_owner_pid = get_pid(task_pid(current));
}
 
/**
 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
 * @gh: the holder structure
 *
 */
 
void gfs2_holder_uninit(struct gfs2_holder *gh)
{
<------>put_pid(gh->gh_owner_pid);
<------>gfs2_glock_put(gh->gh_gl);
<------>gfs2_holder_mark_uninitialized(gh);
<------>gh->gh_ip = 0;
}
 
static void gfs2_glock_update_hold_time(struct gfs2_glock *gl,
<------><------><------><------><------>unsigned long start_time)
{
<------>/* Have we waited longer that a second? */
<------>if (time_after(jiffies, start_time + HZ)) {
<------><------>/* Lengthen the minimum hold time. */
<------><------>gl->gl_hold_time = min(gl->gl_hold_time + GL_GLOCK_HOLD_INCR,
<------><------><------><------>       GL_GLOCK_MAX_HOLD);
<------>}
}
 
/**
 * gfs2_glock_wait - wait on a glock acquisition
 * @gh: the glock holder
 *
 * Returns: 0 on success
 */
 
int gfs2_glock_wait(struct gfs2_holder *gh)
{
<------>unsigned long start_time = jiffies;
 
<------>might_sleep();
<------>wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
<------>gfs2_glock_update_hold_time(gh->gh_gl, start_time);
<------>return gh->gh_error;
}
 
static int glocks_pending(unsigned int num_gh, struct gfs2_holder *ghs)
{
<------>int i;
 
<------>for (i = 0; i < num_gh; i++)
<------><------>if (test_bit(HIF_WAIT, &ghs[i].gh_iflags))
<------><------><------>return 1;
<------>return 0;
}
 
/**
 * gfs2_glock_async_wait - wait on multiple asynchronous glock acquisitions
 * @num_gh: the number of holders in the array
 * @ghs: the glock holder array
 *
 * Returns: 0 on success, meaning all glocks have been granted and are held.
 *          -ESTALE if the request timed out, meaning all glocks were released,
 *          and the caller should retry the operation.
 */
 
int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs)
{
<------>struct gfs2_sbd *sdp = ghs[0].gh_gl->gl_name.ln_sbd;
<------>int i, ret = 0, timeout = 0;
<------>unsigned long start_time = jiffies;
<------>bool keep_waiting;
 
<------>might_sleep();
<------>/*
<------> * Total up the (minimum hold time * 2) of all glocks and use that to
<------> * determine the max amount of time we should wait.
<------> */
<------>for (i = 0; i < num_gh; i++)
<------><------>timeout += ghs[i].gh_gl->gl_hold_time << 1;
 
wait_for_dlm:
<------>if (!wait_event_timeout(sdp->sd_async_glock_wait,
<------><------><------><------>!glocks_pending(num_gh, ghs), timeout))
<------><------>ret = -ESTALE; /* request timed out. */
 
<------>/*
<------> * If dlm granted all our requests, we need to adjust the glock
<------> * minimum hold time values according to how long we waited.
<------> *
<------> * If our request timed out, we need to repeatedly release any held
<------> * glocks we acquired thus far to allow dlm to acquire the remaining
<------> * glocks without deadlocking.  We cannot currently cancel outstanding
<------> * glock acquisitions.
<------> *
<------> * The HIF_WAIT bit tells us which requests still need a response from
<------> * dlm.
<------> *
<------> * If dlm sent us any errors, we return the first error we find.
<------> */
<------>keep_waiting = false;
<------>for (i = 0; i < num_gh; i++) {
<------><------>/* Skip holders we have already dequeued below. */
<------><------>if (!gfs2_holder_queued(&ghs[i]))
<------><------><------>continue;
<------><------>/* Skip holders with a pending DLM response. */
<------><------>if (test_bit(HIF_WAIT, &ghs[i].gh_iflags)) {
<------><------><------>keep_waiting = true;
<------><------><------>continue;
<------><------>}
 
<------><------>if (test_bit(HIF_HOLDER, &ghs[i].gh_iflags)) {
<------><------><------>if (ret == -ESTALE)
<------><------><------><------>gfs2_glock_dq(&ghs[i]);
<------><------><------>else
<------><------><------><------>gfs2_glock_update_hold_time(ghs[i].gh_gl,
<------><------><------><------><------><------><------>    start_time);
<------><------>}
<------><------>if (!ret)
<------><------><------>ret = ghs[i].gh_error;
<------>}
 
<------>if (keep_waiting)
<------><------>goto wait_for_dlm;
 
<------>/*
<------> * At this point, we've either acquired all locks or released them all.
<------> */
<------>return ret;
}
 
/**
 * 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)
{
<------>if (delay)
<------><------>set_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
<------>else
<------><------>gfs2_set_demote(gl);
<------>if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
<------><------>gl->gl_demote_state = state;
<------><------>gl->gl_demote_time = jiffies;
<------>} else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
<------><------><------>gl->gl_demote_state != state) {
<------><------>gl->gl_demote_state = LM_ST_UNLOCKED;
<------>}
<------>if (gl->gl_ops->go_callback)
<------><------>gl->gl_ops->go_callback(gl, remote);
<------>trace_gfs2_demote_rq(gl, remote);
}
 
void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
{
<------>struct va_format vaf;
<------>va_list args;
 
<------>va_start(args, fmt);
 
<------>if (seq) {
<------><------>seq_vprintf(seq, fmt, args);
<------>} else {
<------><------>vaf.fmt = fmt;
<------><------>vaf.va = &args;
 
<------><------>pr_err("%pV", &vaf);
<------>}
 
<------>va_end(args);
}
 
/**
 * add_to_queue - Add a holder to the wait queue (but look for recursion)
 * @gh: the holder structure to add
 *
 * Eventually we should move the recursive locking trap to a
 * debugging option or something like that. This is the fast
 * path and needs to have the minimum number of distractions.
 * 
 */
 
static inline void add_to_queue(struct gfs2_holder *gh)
__releases(&gl->gl_lockref.lock)
__acquires(&gl->gl_lockref.lock)
{
<------>struct gfs2_glock *gl = gh->gh_gl;
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
<------>struct list_head *insert_pt = NULL;
<------>struct gfs2_holder *gh2;
<------>int try_futile = 0;
 
<------>GLOCK_BUG_ON(gl, gh->gh_owner_pid == NULL);
<------>if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
<------><------>GLOCK_BUG_ON(gl, true);
 
<------>if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
<------><------>if (test_bit(GLF_LOCK, &gl->gl_flags))
<------><------><------>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;
<------>}
<------>trace_gfs2_glock_queue(gh, 1);
<------>gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT);
<------>gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT);
<------>if (likely(insert_pt == NULL)) {
<------><------>list_add_tail(&gh->gh_list, &gl->gl_holders);
<------><------>if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
<------><------><------>goto do_cancel;
<------><------>return;
<------>}
<------>list_add_tail(&gh->gh_list, insert_pt);
do_cancel:
<------>gh = list_first_entry(&gl->gl_holders, struct gfs2_holder, gh_list);
<------>if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
<------><------>spin_unlock(&gl->gl_lockref.lock);
<------><------>if (sdp->sd_lockstruct.ls_ops->lm_cancel)
<------><------><------>sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
<------><------>spin_lock(&gl->gl_lockref.lock);
<------>}
<------>return;
 
trap_recursive:
<------>fs_err(sdp, "original: %pSR\n", (void *)gh2->gh_ip);
<------>fs_err(sdp, "pid: %d\n", pid_nr(gh2->gh_owner_pid));
<------>fs_err(sdp, "lock type: %d req lock state : %d\n",
<------>       gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
<------>fs_err(sdp, "new: %pSR\n", (void *)gh->gh_ip);
<------>fs_err(sdp, "pid: %d\n", pid_nr(gh->gh_owner_pid));
<------>fs_err(sdp, "lock type: %d req lock state : %d\n",
<------>       gh->gh_gl->gl_name.ln_type, gh->gh_state);
<------>gfs2_dump_glock(NULL, gl, true);
<------>BUG();
}
 
/**
 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
 * @gh: the holder structure
 *
 * if (gh->gh_flags & GL_ASYNC), this never returns an error
 *
 * Returns: 0, GLR_TRYFAILED, or errno on failure
 */
 
int gfs2_glock_nq(struct gfs2_holder *gh)
{
<------>struct gfs2_glock *gl = gh->gh_gl;
<------>int error = 0;
 
<------>if (glock_blocked_by_withdraw(gl) && !(gh->gh_flags & LM_FLAG_NOEXP))
<------><------>return -EIO;
 
<------>if (test_bit(GLF_LRU, &gl->gl_flags))
<------><------>gfs2_glock_remove_from_lru(gl);
 
<------>spin_lock(&gl->gl_lockref.lock);
<------>add_to_queue(gh);
<------>if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&
<------><------>     test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
<------><------>set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
<------><------>gl->gl_lockref.count++;
<------><------>__gfs2_glock_queue_work(gl, 0);
<------>}
<------>run_queue(gl, 1);
<------>spin_unlock(&gl->gl_lockref.lock);
 
<------>if (!(gh->gh_flags & GL_ASYNC))
<------><------>error = gfs2_glock_wait(gh);
 
<------>return error;
}
 
/**
 * gfs2_glock_poll - poll to see if an async request has been completed
 * @gh: the holder
 *
 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
 */
 
int gfs2_glock_poll(struct gfs2_holder *gh)
{
<------>return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
}
 
/**
 * 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;
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
<------>unsigned delay = 0;
<------>int fast_path = 0;
 
<------>spin_lock(&gl->gl_lockref.lock);
<------>/*
<------> * If we're in the process of file system withdraw, we cannot just
<------> * dequeue any glocks until our journal is recovered, lest we
<------> * introduce file system corruption. We need two exceptions to this
<------> * rule: We need to allow unlocking of nondisk glocks and the glock
<------> * for our own journal that needs recovery.
<------> */
<------>if (test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags) &&
<------>    glock_blocked_by_withdraw(gl) &&
<------>    gh->gh_gl != sdp->sd_jinode_gl) {
<------><------>sdp->sd_glock_dqs_held++;
<------><------>spin_unlock(&gl->gl_lockref.lock);
<------><------>might_sleep();
<------><------>wait_on_bit(&sdp->sd_flags, SDF_WITHDRAW_RECOVERY,
<------><------><------>    TASK_UNINTERRUPTIBLE);
<------><------>spin_lock(&gl->gl_lockref.lock);
<------>}
<------>if (gh->gh_flags & GL_NOCACHE)
<------><------>handle_callback(gl, LM_ST_UNLOCKED, 0, false);
 
<------>list_del_init(&gh->gh_list);
<------>clear_bit(HIF_HOLDER, &gh->gh_iflags);
<------>if (find_first_holder(gl) == NULL) {
<------><------>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);
<------>if (unlikely(!fast_path)) {
<------><------>gl->gl_lockref.count++;
<------><------>if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
<------><------>    !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
<------><------>    gl->gl_name.ln_type == LM_TYPE_INODE)
<------><------><------>delay = gl->gl_hold_time;
<------><------>__gfs2_glock_queue_work(gl, delay);
<------>}
<------>spin_unlock(&gl->gl_lockref.lock);
}
 
void gfs2_glock_dq_wait(struct gfs2_holder *gh)
{
<------>struct gfs2_glock *gl = gh->gh_gl;
<------>gfs2_glock_dq(gh);
<------>might_sleep();
<------>wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE);
}
 
/**
 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
 * @gh: the holder structure
 *
 */
 
void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
{
<------>gfs2_glock_dq(gh);
<------>gfs2_holder_uninit(gh);
}
 
/**
 * gfs2_glock_nq_num - acquire a glock based on lock number
 * @sdp: the filesystem
 * @number: the lock number
 * @glops: the glock operations for the type of glock
 * @state: the state to acquire the glock in
 * @flags: modifier flags for the acquisition
 * @gh: the struct gfs2_holder
 *
 * Returns: errno
 */
 
int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
<------><------>      const struct gfs2_glock_operations *glops,
<------><------>      unsigned int state, u16 flags, struct gfs2_holder *gh)
{
<------>struct gfs2_glock *gl;
<------>int error;
 
<------>error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
<------>if (!error) {
<------><------>error = gfs2_glock_nq_init(gl, state, flags, gh);
<------><------>gfs2_glock_put(gl);
<------>}
 
<------>return error;
}
 
/**
 * glock_compare - Compare two struct gfs2_glock structures for sorting
 * @arg_a: the first structure
 * @arg_b: the second structure
 *
 */
 
static int glock_compare(const void *arg_a, const void *arg_b)
{
<------>const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
<------>const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
<------>const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
<------>const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
 
<------>if (a->ln_number > b->ln_number)
<------><------>return 1;
<------>if (a->ln_number < b->ln_number)
<------><------>return -1;
<------>BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
<------>return 0;
}
 
/**
 * nq_m_sync - 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_array(num_gh, sizeof(struct gfs2_holder *),
<------><------><------><------>    GFP_NOFS);
<------><------>if (!pph)
<------><------><------>return -ENOMEM;
<------>}
 
<------>error = nq_m_sync(num_gh, ghs, pph);
 
<------>if (pph != tmp)
<------><------>kfree(pph);
 
<------>return error;
}
 
/**
 * gfs2_glock_dq_m - release multiple glocks
 * @num_gh: the number of structures
 * @ghs: an array of struct gfs2_holder structures
 *
 */
 
void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
{
<------>while (num_gh--)
<------><------>gfs2_glock_dq(&ghs[num_gh]);
}
 
void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
{
<------>unsigned long delay = 0;
<------>unsigned long holdtime;
<------>unsigned long now = jiffies;
 
<------>gfs2_glock_hold(gl);
<------>spin_lock(&gl->gl_lockref.lock);
<------>holdtime = gl->gl_tchange + gl->gl_hold_time;
<------>if (!list_empty(&gl->gl_holders) &&
<------>    gl->gl_name.ln_type == LM_TYPE_INODE) {
<------><------>if (time_before(now, holdtime))
<------><------><------>delay = holdtime - now;
<------><------>if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
<------><------><------>delay = gl->gl_hold_time;
<------>}
<------>handle_callback(gl, state, delay, true);
<------>__gfs2_glock_queue_work(gl, delay);
<------>spin_unlock(&gl->gl_lockref.lock);
}
 
/**
 * gfs2_should_freeze - Figure out if glock should be frozen
 * @gl: The glock in question
 *
 * Glocks are not frozen if (a) the result of the dlm operation is
 * an error, (b) the locking operation was an unlock operation or
 * (c) if there is a "noexp" flagged request anywhere in the queue
 *
 * Returns: 1 if freezing should occur, 0 otherwise
 */
 
static int gfs2_should_freeze(const struct gfs2_glock *gl)
{
<------>const struct gfs2_holder *gh;
 
<------>if (gl->gl_reply & ~LM_OUT_ST_MASK)
<------><------>return 0;
<------>if (gl->gl_target == LM_ST_UNLOCKED)
<------><------>return 0;
 
<------>list_for_each_entry(gh, &gl->gl_holders, gh_list) {
<------><------>if (test_bit(HIF_HOLDER, &gh->gh_iflags))
<------><------><------>continue;
<------><------>if (LM_FLAG_NOEXP & gh->gh_flags)
<------><------><------>return 0;
<------>}
 
<------>return 1;
}
 
/**
 * gfs2_glock_complete - Callback used by locking
 * @gl: Pointer to the glock
 * @ret: The return value from the dlm
 *
 * The gl_reply field is under the gl_lockref.lock lock so that it is ok
 * to use a bitfield shared with other glock state fields.
 */
 
void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
{
<------>struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
 
<------>spin_lock(&gl->gl_lockref.lock);
<------>gl->gl_reply = ret;
 
<------>if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
<------><------>if (gfs2_should_freeze(gl)) {
<------><------><------>set_bit(GLF_FROZEN, &gl->gl_flags);
<------><------><------>spin_unlock(&gl->gl_lockref.lock);
<------><------><------>return;
<------><------>}
<------>}
 
<------>gl->gl_lockref.count++;
<------>set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
<------>__gfs2_glock_queue_work(gl, 0);
<------>spin_unlock(&gl->gl_lockref.lock);
}
 
static int glock_cmp(void *priv, 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_first_entry(list, struct gfs2_glock, gl_lru);
<------><------>list_del_init(&gl->gl_lru);
<------><------>clear_bit(GLF_LRU, &gl->gl_flags);
<------><------>if (!spin_trylock(&gl->gl_lockref.lock)) {
add_back_to_lru:
<------><------><------>list_add(&gl->gl_lru, &lru_list);
<------><------><------>set_bit(GLF_LRU, &gl->gl_flags);
<------><------><------>atomic_inc(&lru_count);
<------><------><------>continue;
<------><------>}
<------><------>if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
<------><------><------>spin_unlock(&gl->gl_lockref.lock);
<------><------><------>goto add_back_to_lru;
<------><------>}
<------><------>gl->gl_lockref.count++;
<------><------>if (demote_ok(gl))
<------><------><------>handle_callback(gl, LM_ST_UNLOCKED, 0, false);
<------><------>WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
<------><------>__gfs2_glock_queue_work(gl, 0);
<------><------>spin_unlock(&gl->gl_lockref.lock);
<------><------>cond_resched_lock(&lru_lock);
<------>}
}
 
/**
 * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
 * @nr: The number of entries to scan
 *
 * This function selects the entries on the LRU which are able to
 * be demoted, and then kicks off the process by calling
 * gfs2_dispose_glock_lru() above.
 */
 
static long gfs2_scan_glock_lru(int nr)
{
<------>struct gfs2_glock *gl;
<------>LIST_HEAD(skipped);
<------>LIST_HEAD(dispose);
<------>long freed = 0;
 
<------>spin_lock(&lru_lock);
<------>while ((nr-- >= 0) && !list_empty(&lru_list)) {
<------><------>gl = list_first_entry(&lru_list, struct gfs2_glock, gl_lru);
 
<------><------>/* Test for being demotable */
<------><------>if (!test_bit(GLF_LOCK, &gl->gl_flags)) {
<------><------><------>list_move(&gl->gl_lru, &dispose);
<------><------><------>atomic_dec(&lru_count);
<------><------><------>freed++;
<------><------><------>continue;
<------><------>}
 
<------><------>list_move(&gl->gl_lru, &skipped);
<------>}
<------>list_splice(&skipped, &lru_list);
<------>if (!list_empty(&dispose))
<------><------>gfs2_dispose_glock_lru(&dispose);
<------>spin_unlock(&lru_lock);
 
<------>return freed;
}
 
static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink,
<------><------><------><------><------>    struct shrink_control *sc)
{
<------>if (!(sc->gfp_mask & __GFP_FS))
<------><------>return SHRINK_STOP;
<------>return gfs2_scan_glock_lru(sc->nr_to_scan);
}
 
static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink,
<------><------><------><------><------>     struct shrink_control *sc)
{
<------>return vfs_pressure_ratio(atomic_read(&lru_count));
}
 
static struct shrinker glock_shrinker = {
<------>.seeks = DEFAULT_SEEKS,
<------>.count_objects = gfs2_glock_shrink_count,
<------>.scan_objects = gfs2_glock_shrink_scan,
};
 
/**
 * glock_hash_walk - Call a function for glock in a hash bucket
 * @examiner: the function
 * @sdp: the filesystem
 *
 * Note that the function can be called multiple times on the same
 * object.  So the user must ensure that the function can cope with
 * that.
 */
 
static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
{
<------>struct gfs2_glock *gl;
<------>struct rhashtable_iter iter;
 
<------>rhashtable_walk_enter(&gl_hash_table, &iter);
 
<------>do {
<------><------>rhashtable_walk_start(&iter);
 
<------><------>while ((gl = rhashtable_walk_next(&iter)) && !IS_ERR(gl)) {
<------><------><------>if (gl->gl_name.ln_sbd == sdp)
<------><------><------><------>examiner(gl);
<------><------>}
 
<------><------>rhashtable_walk_stop(&iter);
<------>} while (cond_resched(), gl == ERR_PTR(-EAGAIN));
 
<------>rhashtable_walk_exit(&iter);
}
 
bool gfs2_queue_delete_work(struct gfs2_glock *gl, unsigned long delay)
{
<------>bool queued;
 
<------>spin_lock(&gl->gl_lockref.lock);
<------>queued = queue_delayed_work(gfs2_delete_workqueue,
<------><------><------><------>    &gl->gl_delete, delay);
<------>if (queued)
<------><------>set_bit(GLF_PENDING_DELETE, &gl->gl_flags);
<------>spin_unlock(&gl->gl_lockref.lock);
<------>return queued;
}
 
void gfs2_cancel_delete_work(struct gfs2_glock *gl)
{
<------>if (cancel_delayed_work(&gl->gl_delete)) {
<------><------>clear_bit(GLF_PENDING_DELETE, &gl->gl_flags);
<------><------>gfs2_glock_put(gl);
<------>}
}
 
bool gfs2_delete_work_queued(const struct gfs2_glock *gl)
{
<------>return test_bit(GLF_PENDING_DELETE, &gl->gl_flags);
}
 
static void flush_delete_work(struct gfs2_glock *gl)
{
<------>if (gl->gl_name.ln_type == LM_TYPE_IOPEN) {
<------><------>if (cancel_delayed_work(&gl->gl_delete)) {
<------><------><------>queue_delayed_work(gfs2_delete_workqueue,
<------><------><------><------><------>   &gl->gl_delete, 0);
<------><------>}
<------>}
}
 
void gfs2_flush_delete_work(struct gfs2_sbd *sdp)
{
<------>glock_hash_walk(flush_delete_work, sdp);
<------>flush_workqueue(gfs2_delete_workqueue);
}
 
/**
 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
 * @gl: The glock to thaw
 *
 */
 
static void thaw_glock(struct gfs2_glock *gl)
{
<------>if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
<------><------>return;
<------>if (!lockref_get_not_dead(&gl->gl_lockref))
<------><------>return;
<------>set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
<------>gfs2_glock_queue_work(gl, 0);
}
 
/**
 * clear_glock - look at a glock and see if we can free it from glock cache
 * @gl: the glock to look at
 *
 */
 
static void clear_glock(struct gfs2_glock *gl)
{
<------>gfs2_glock_remove_from_lru(gl);
 
<------>spin_lock(&gl->gl_lockref.lock);
<------>if (!__lockref_is_dead(&gl->gl_lockref)) {
<------><------>gl->gl_lockref.count++;
<------><------>if (gl->gl_state != LM_ST_UNLOCKED)
<------><------><------>handle_callback(gl, LM_ST_UNLOCKED, 0, false);
<------><------>__gfs2_glock_queue_work(gl, 0);
<------>}
<------>spin_unlock(&gl->gl_lockref.lock);
}
 
/**
 * gfs2_glock_thaw - Thaw any frozen glocks
 * @sdp: The super block
 *
 */
 
void gfs2_glock_thaw(struct gfs2_sbd *sdp)
{
<------>glock_hash_walk(thaw_glock, sdp);
}
 
static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid)
{
<------>spin_lock(&gl->gl_lockref.lock);
<------>gfs2_dump_glock(seq, gl, fsid);
<------>spin_unlock(&gl->gl_lockref.lock);
}
 
static void dump_glock_func(struct gfs2_glock *gl)
{
<------>dump_glock(NULL, gl, true);
}
 
/**
 * 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_timeout(sdp->sd_glock_wait,
<------><------><------>   atomic_read(&sdp->sd_glock_disposal) == 0,
<------><------><------>   HZ * 600);
<------>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_glock_assert_withdraw(gl, ret == 0);
 
<------>spin_lock(&gl->gl_lockref.lock);
<------>clear_bit(GLF_LOCK, &gl->gl_flags);
<------>run_queue(gl, 1);
<------>spin_unlock(&gl->gl_lockref.lock);
}
 
static const char *state2str(unsigned state)
{
<------>switch(state) {
<------>case LM_ST_UNLOCKED:
<------><------>return "UN";
<------>case LM_ST_SHARED:
<------><------>return "SH";
<------>case LM_ST_DEFERRED:
<------><------>return "DF";
<------>case LM_ST_EXCLUSIVE:
<------><------>return "EX";
<------>}
<------>return "??";
}
 
static const char *hflags2str(char *buf, u16 flags, unsigned long iflags)
{
<------>char *p = buf;
<------>if (flags & LM_FLAG_TRY)
<------><------>*p++ = 't';
<------>if (flags & LM_FLAG_TRY_1CB)
<------><------>*p++ = 'T';
<------>if (flags & LM_FLAG_NOEXP)
<------><------>*p++ = 'e';
<------>if (flags & LM_FLAG_ANY)
<------><------>*p++ = 'A';
<------>if (flags & LM_FLAG_PRIORITY)
<------><------>*p++ = 'p';
<------>if (flags & 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
 * @fs_id_buf: pointer to file system id (if requested)
 *
 */
 
static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh,
<------><------><------>const char *fs_id_buf)
{
<------>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, "%s H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
<------><------>       fs_id_buf, state2str(gh->gh_state),
<------><------>       hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
<------><------>       gh->gh_error,
<------><------>       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 (!list_empty(&gl->gl_holders))
<------><------>*p++ = 'q';
<------>if (test_bit(GLF_LRU, gflags))
<------><------>*p++ = 'L';
<------>if (gl->gl_object)
<------><------>*p++ = 'o';
<------>if (test_bit(GLF_BLOCKING, gflags))
<------><------>*p++ = 'b';
<------>if (test_bit(GLF_INODE_CREATING, gflags))
<------><------>*p++ = 'c';
<------>if (test_bit(GLF_PENDING_DELETE, gflags))
<------><------>*p++ = 'P';
<------>if (test_bit(GLF_FREEING, gflags))
<------><------>*p++ = 'x';
<------>*p = 0;
<------>return buf;
}
 
/**
 * gfs2_dump_glock - print information about a glock
 * @seq: The seq_file struct
 * @gl: the glock
 * @fsid: If true, also dump the file system id
 *
 * The file format is as follows:
 * One line per object, capital letters are used to indicate objects
 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
 * other objects are indented by a single space and follow the glock to
 * which they are related. Fields are indicated by lower case letters
 * followed by a colon and the field value, except for strings which are in
 * [] so that its possible to see if they are composed of spaces for
 * example. The field's are n = number (id of the object), f = flags,
 * t = type, s = state, r = refcount, e = error, p = pid.
 *
 */
 
void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid)
{
<------>const struct gfs2_glock_operations *glops = gl->gl_ops;
<------>unsigned long long dtime;
<------>const struct gfs2_holder *gh;
<------>char gflags_buf[32];
<------>struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
<------>char fs_id_buf[sizeof(sdp->sd_fsname) + 7];
<------>unsigned long nrpages = 0;
 
<------>if (gl->gl_ops->go_flags & GLOF_ASPACE) {
<------><------>struct address_space *mapping = gfs2_glock2aspace(gl);
 
<------><------>nrpages = mapping->nrpages;
<------>}
<------>memset(fs_id_buf, 0, sizeof(fs_id_buf));
<------>if (fsid && sdp) /* safety precaution */
<------><------>sprintf(fs_id_buf, "fsid=%s: ", sdp->sd_fsname);
<------>dtime = jiffies - gl->gl_demote_time;
<------>dtime *= 1000000/HZ; /* demote time in uSec */
<------>if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
<------><------>dtime = 0;
<------>gfs2_print_dbg(seq, "%sG:  s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d "
<------><------>       "v:%d r:%d m:%ld p:%lu\n",
<------><------>       fs_id_buf, state2str(gl->gl_state),
<------><------>       gl->gl_name.ln_type,
<------><------>       (unsigned long long)gl->gl_name.ln_number,
<------><------>       gflags2str(gflags_buf, gl),
<------><------>       state2str(gl->gl_target),
<------><------>       state2str(gl->gl_demote_state), dtime,
<------><------>       atomic_read(&gl->gl_ail_count),
<------><------>       atomic_read(&gl->gl_revokes),
<------><------>       (int)gl->gl_lockref.count, gl->gl_hold_time, nrpages);
 
<------>list_for_each_entry(gh, &gl->gl_holders, gh_list)
<------><------>dump_holder(seq, gh, fs_id_buf);
 
<------>if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
<------><------>glops->go_dump(seq, gl, fs_id_buf);
}
 
static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
{
<------>struct gfs2_glock *gl = iter_ptr;
 
<------>seq_printf(seq, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n",
<------><------>   gl->gl_name.ln_type,
<------><------>   (unsigned long long)gl->gl_name.ln_number,
<------><------>   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
<------><------>   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
<------><------>   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
<------><------>   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
<------><------>   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
<------><------>   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
<------><------>   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
<------><------>   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
<------>return 0;
}
 
static const char *gfs2_gltype[] = {
<------>"type",
<------>"reserved",
<------>"nondisk",
<------>"inode",
<------>"rgrp",
<------>"meta",
<------>"iopen",
<------>"flock",
<------>"plock",
<------>"quota",
<------>"journal",
};
 
static const char *gfs2_stype[] = {
<------>[GFS2_LKS_SRTT]		= "srtt",
<------>[GFS2_LKS_SRTTVAR]	= "srttvar",
<------>[GFS2_LKS_SRTTB]	= "srttb",
<------>[GFS2_LKS_SRTTVARB]	= "srttvarb",
<------>[GFS2_LKS_SIRT]		= "sirt",
<------>[GFS2_LKS_SIRTVAR]	= "sirtvar",
<------>[GFS2_LKS_DCOUNT]	= "dlm",
<------>[GFS2_LKS_QCOUNT]	= "queue",
};
 
#define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
 
static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
{
<------>struct gfs2_sbd *sdp = seq->private;
<------>loff_t pos = *(loff_t *)iter_ptr;
<------>unsigned index = pos >> 3;
<------>unsigned subindex = pos & 0x07;
<------>int i;
 
<------>if (index == 0 && subindex != 0)
<------><------>return 0;
 
<------>seq_printf(seq, "%-10s %8s:", gfs2_gltype[index],
<------><------>   (index == 0) ? "cpu": gfs2_stype[subindex]);
 
<------>for_each_possible_cpu(i) {
                const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i);
 
<------><------>if (index == 0)
<------><------><------>seq_printf(seq, " %15u", i);
<------><------>else
<------><------><------>seq_printf(seq, " %15llu", (unsigned long long)lkstats->
<------><------><------><------>   lkstats[index - 1].stats[subindex]);
<------>}
<------>seq_putc(seq, '\n');
<------>return 0;
}
 
int __init gfs2_glock_init(void)
{
<------>int i, ret;
 
<------>ret = rhashtable_init(&gl_hash_table, &ht_parms);
<------>if (ret < 0)
<------><------>return ret;
 
<------>glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
<------><------><------><------><------>  WQ_HIGHPRI | WQ_FREEZABLE, 0);
<------>if (!glock_workqueue) {
<------><------>rhashtable_destroy(&gl_hash_table);
<------><------>return -ENOMEM;
<------>}
<------>gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
<------><------><------><------><------><------>WQ_MEM_RECLAIM | WQ_FREEZABLE,
<------><------><------><------><------><------>0);
<------>if (!gfs2_delete_workqueue) {
<------><------>destroy_workqueue(glock_workqueue);
<------><------>rhashtable_destroy(&gl_hash_table);
<------><------>return -ENOMEM;
<------>}
 
<------>ret = register_shrinker(&glock_shrinker);
<------>if (ret) {
<------><------>destroy_workqueue(gfs2_delete_workqueue);
<------><------>destroy_workqueue(glock_workqueue);
<------><------>rhashtable_destroy(&gl_hash_table);
<------><------>return ret;
<------>}
 
<------>for (i = 0; i < GLOCK_WAIT_TABLE_SIZE; i++)
<------><------>init_waitqueue_head(glock_wait_table + i);
 
<------>return 0;
}
 
void gfs2_glock_exit(void)
{
<------>unregister_shrinker(&glock_shrinker);
<------>rhashtable_destroy(&gl_hash_table);
<------>destroy_workqueue(glock_workqueue);
<------>destroy_workqueue(gfs2_delete_workqueue);
}
 
static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi, loff_t n)
{
<------>struct gfs2_glock *gl = gi->gl;
 
<------>if (gl) {
<------><------>if (n == 0)
<------><------><------>return;
<------><------>if (!lockref_put_not_zero(&gl->gl_lockref))
<------><------><------>gfs2_glock_queue_put(gl);
<------>}
<------>for (;;) {
<------><------>gl = rhashtable_walk_next(&gi->hti);
<------><------>if (IS_ERR_OR_NULL(gl)) {
<------><------><------>if (gl == ERR_PTR(-EAGAIN)) {
<------><------><------><------>n = 1;
<------><------><------><------>continue;
<------><------><------>}
<------><------><------>gl = NULL;
<------><------><------>break;
<------><------>}
<------><------>if (gl->gl_name.ln_sbd != gi->sdp)
<------><------><------>continue;
<------><------>if (n <= 1) {
<------><------><------>if (!lockref_get_not_dead(&gl->gl_lockref))
<------><------><------><------>continue;
<------><------><------>break;
<------><------>} else {
<------><------><------>if (__lockref_is_dead(&gl->gl_lockref))
<------><------><------><------>continue;
<------><------><------>n--;
<------><------>}
<------>}
<------>gi->gl = gl;
}
 
static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
<------>__acquires(RCU)
{
<------>struct gfs2_glock_iter *gi = seq->private;
<------>loff_t n;
 
<------>/*
<------> * We can either stay where we are, skip to the next hash table
<------> * entry, or start from the beginning.
<------> */
<------>if (*pos < gi->last_pos) {
<------><------>rhashtable_walk_exit(&gi->hti);
<------><------>rhashtable_walk_enter(&gl_hash_table, &gi->hti);
<------><------>n = *pos + 1;
<------>} else {
<------><------>n = *pos - gi->last_pos;
<------>}
 
<------>rhashtable_walk_start(&gi->hti);
 
<------>gfs2_glock_iter_next(gi, n);
<------>gi->last_pos = *pos;
<------>return gi->gl;
}
 
static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
<------><------><------><------> loff_t *pos)
{
<------>struct gfs2_glock_iter *gi = seq->private;
 
<------>(*pos)++;
<------>gi->last_pos = *pos;
<------>gfs2_glock_iter_next(gi, 1);
<------>return gi->gl;
}
 
static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
<------>__releases(RCU)
{
<------>struct gfs2_glock_iter *gi = seq->private;
 
<------>rhashtable_walk_stop(&gi->hti);
}
 
static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
{
<------>dump_glock(seq, iter_ptr, false);
<------>return 0;
}
 
static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
{
<------>preempt_disable();
<------>if (*pos >= GFS2_NR_SBSTATS)
<------><------>return NULL;
<------>return pos;
}
 
static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
<------><------><------><------>   loff_t *pos)
{
<------>(*pos)++;
<------>if (*pos >= GFS2_NR_SBSTATS)
<------><------>return NULL;
<------>return pos;
}
 
static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr)
{
<------>preempt_enable();
}
 
static const struct seq_operations gfs2_glock_seq_ops = {
<------>.start = gfs2_glock_seq_start,
<------>.next  = gfs2_glock_seq_next,
<------>.stop  = gfs2_glock_seq_stop,
<------>.show  = gfs2_glock_seq_show,
};
 
static const struct seq_operations gfs2_glstats_seq_ops = {
<------>.start = gfs2_glock_seq_start,
<------>.next  = gfs2_glock_seq_next,
<------>.stop  = gfs2_glock_seq_stop,
<------>.show  = gfs2_glstats_seq_show,
};
 
static const struct seq_operations gfs2_sbstats_sops = {
<------>.start = gfs2_sbstats_seq_start,
<------>.next  = gfs2_sbstats_seq_next,
<------>.stop  = gfs2_sbstats_seq_stop,
<------>.show  = gfs2_sbstats_seq_show,
};
 
#define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL)
 
static int __gfs2_glocks_open(struct inode *inode, struct file *file,
<------><------><------>      const struct seq_operations *ops)
{
<------>int ret = seq_open_private(file, ops, sizeof(struct gfs2_glock_iter));
<------>if (ret == 0) {
<------><------>struct seq_file *seq = file->private_data;
<------><------>struct gfs2_glock_iter *gi = seq->private;
 
<------><------>gi->sdp = inode->i_private;
<------><------>seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
<------><------>if (seq->buf)
<------><------><------>seq->size = GFS2_SEQ_GOODSIZE;
<------><------>/*
<------><------> * Initially, we are "before" the first hash table entry; the
<------><------> * first call to rhashtable_walk_next gets us the first entry.
<------><------> */
<------><------>gi->last_pos = -1;
<------><------>gi->gl = NULL;
<------><------>rhashtable_walk_enter(&gl_hash_table, &gi->hti);
<------>}
<------>return ret;
}
 
static int gfs2_glocks_open(struct inode *inode, struct file *file)
{
<------>return __gfs2_glocks_open(inode, file, &gfs2_glock_seq_ops);
}
 
static int gfs2_glocks_release(struct inode *inode, struct file *file)
{
<------>struct seq_file *seq = file->private_data;
<------>struct gfs2_glock_iter *gi = seq->private;
 
<------>if (gi->gl)
<------><------>gfs2_glock_put(gi->gl);
<------>rhashtable_walk_exit(&gi->hti);
<------>return seq_release_private(inode, file);
}
 
static int gfs2_glstats_open(struct inode *inode, struct file *file)
{
<------>return __gfs2_glocks_open(inode, file, &gfs2_glstats_seq_ops);
}
 
static const struct file_operations gfs2_glocks_fops = {
<------>.owner   = THIS_MODULE,
<------>.open    = gfs2_glocks_open,
<------>.read    = seq_read,
<------>.llseek  = seq_lseek,
<------>.release = gfs2_glocks_release,
};
 
static const struct file_operations gfs2_glstats_fops = {
<------>.owner   = THIS_MODULE,
<------>.open    = gfs2_glstats_open,
<------>.read    = seq_read,
<------>.llseek  = seq_lseek,
<------>.release = gfs2_glocks_release,
};
 
DEFINE_SEQ_ATTRIBUTE(gfs2_sbstats);
 
void gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
{
<------>sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
 
<------>debugfs_create_file("glocks", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
<------><------><------>    &gfs2_glocks_fops);
 
<------>debugfs_create_file("glstats", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
<------><------><------>    &gfs2_glstats_fops);
 
<------>debugfs_create_file("sbstats", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
<------><------><------>    &gfs2_sbstats_fops);
}
 
void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
{
<------>debugfs_remove_recursive(sdp->debugfs_dir);
<------>sdp->debugfs_dir = NULL;
}
 
void gfs2_register_debugfs(void)
{
<------>gfs2_root = debugfs_create_dir("gfs2", NULL);
}
 
void gfs2_unregister_debugfs(void)
{
<------>debugfs_remove(gfs2_root);
<------>gfs2_root = NULL;
}