1963 lines
47 KiB
C
1963 lines
47 KiB
C
/*
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* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU General Public License version 2.
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*/
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/completion.h>
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#include <linux/buffer_head.h>
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#include <linux/delay.h>
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#include <linux/sort.h>
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#include <linux/jhash.h>
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#include <linux/kallsyms.h>
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#include <linux/gfs2_ondisk.h>
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#include <linux/list.h>
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#include <linux/lm_interface.h>
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#include <linux/wait.h>
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#include <linux/module.h>
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#include <linux/rwsem.h>
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#include <asm/uaccess.h>
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#include <linux/seq_file.h>
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#include <linux/debugfs.h>
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#include <linux/kthread.h>
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#include <linux/freezer.h>
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#include <linux/workqueue.h>
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#include <linux/jiffies.h>
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#include "gfs2.h"
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#include "incore.h"
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#include "glock.h"
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#include "glops.h"
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#include "inode.h"
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#include "lops.h"
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#include "meta_io.h"
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#include "quota.h"
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#include "super.h"
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#include "util.h"
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struct gfs2_gl_hash_bucket {
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struct hlist_head hb_list;
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};
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struct gfs2_glock_iter {
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int hash; /* hash bucket index */
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struct gfs2_sbd *sdp; /* incore superblock */
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struct gfs2_glock *gl; /* current glock struct */
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char string[512]; /* scratch space */
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};
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typedef void (*glock_examiner) (struct gfs2_glock * gl);
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static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
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static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
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#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0)
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static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
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static DECLARE_RWSEM(gfs2_umount_flush_sem);
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static struct dentry *gfs2_root;
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static struct task_struct *scand_process;
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static unsigned int scand_secs = 5;
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static struct workqueue_struct *glock_workqueue;
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#define GFS2_GL_HASH_SHIFT 15
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#define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
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#define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
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static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
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static struct dentry *gfs2_root;
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/*
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* Despite what you might think, the numbers below are not arbitrary :-)
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* They are taken from the ipv4 routing hash code, which is well tested
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* and thus should be nearly optimal. Later on we might tweek the numbers
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* but for now this should be fine.
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*
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* The reason for putting the locks in a separate array from the list heads
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* is that we can have fewer locks than list heads and save memory. We use
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* the same hash function for both, but with a different hash mask.
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*/
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
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defined(CONFIG_PROVE_LOCKING)
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#ifdef CONFIG_LOCKDEP
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# define GL_HASH_LOCK_SZ 256
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#else
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# if NR_CPUS >= 32
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# define GL_HASH_LOCK_SZ 4096
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# elif NR_CPUS >= 16
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# define GL_HASH_LOCK_SZ 2048
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# elif NR_CPUS >= 8
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# define GL_HASH_LOCK_SZ 1024
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# elif NR_CPUS >= 4
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# define GL_HASH_LOCK_SZ 512
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# else
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# define GL_HASH_LOCK_SZ 256
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# endif
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#endif
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/* We never want more locks than chains */
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#if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
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# undef GL_HASH_LOCK_SZ
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# define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
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#endif
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static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
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static inline rwlock_t *gl_lock_addr(unsigned int x)
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{
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return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
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}
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#else /* not SMP, so no spinlocks required */
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static inline rwlock_t *gl_lock_addr(unsigned int x)
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{
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return NULL;
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}
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#endif
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/**
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* gl_hash() - Turn glock number into hash bucket number
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* @lock: The glock number
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*
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* Returns: The number of the corresponding hash bucket
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*/
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static unsigned int gl_hash(const struct gfs2_sbd *sdp,
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const struct lm_lockname *name)
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{
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unsigned int h;
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h = jhash(&name->ln_number, sizeof(u64), 0);
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h = jhash(&name->ln_type, sizeof(unsigned int), h);
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h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
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h &= GFS2_GL_HASH_MASK;
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return h;
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}
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/**
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* glock_free() - Perform a few checks and then release struct gfs2_glock
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* @gl: The glock to release
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*
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* Also calls lock module to release its internal structure for this glock.
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*
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*/
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static void glock_free(struct gfs2_glock *gl)
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{
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struct gfs2_sbd *sdp = gl->gl_sbd;
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struct inode *aspace = gl->gl_aspace;
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if (sdp->sd_lockstruct.ls_ops->lm_put_lock)
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sdp->sd_lockstruct.ls_ops->lm_put_lock(gl->gl_lock);
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if (aspace)
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gfs2_aspace_put(aspace);
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kmem_cache_free(gfs2_glock_cachep, gl);
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}
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/**
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* gfs2_glock_hold() - increment reference count on glock
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* @gl: The glock to hold
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*
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*/
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static void gfs2_glock_hold(struct gfs2_glock *gl)
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{
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atomic_inc(&gl->gl_ref);
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}
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/**
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* gfs2_glock_put() - Decrement reference count on glock
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* @gl: The glock to put
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*
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*/
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int gfs2_glock_put(struct gfs2_glock *gl)
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{
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int rv = 0;
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write_lock(gl_lock_addr(gl->gl_hash));
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if (atomic_dec_and_test(&gl->gl_ref)) {
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hlist_del(&gl->gl_list);
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write_unlock(gl_lock_addr(gl->gl_hash));
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GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_UNLOCKED);
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GLOCK_BUG_ON(gl, !list_empty(&gl->gl_reclaim));
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GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
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glock_free(gl);
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rv = 1;
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goto out;
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}
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write_unlock(gl_lock_addr(gl->gl_hash));
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out:
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return rv;
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}
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/**
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* search_bucket() - Find struct gfs2_glock by lock number
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* @bucket: the bucket to search
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* @name: The lock name
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*
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* Returns: NULL, or the struct gfs2_glock with the requested number
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*/
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static struct gfs2_glock *search_bucket(unsigned int hash,
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const struct gfs2_sbd *sdp,
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const struct lm_lockname *name)
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{
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struct gfs2_glock *gl;
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struct hlist_node *h;
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hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
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if (!lm_name_equal(&gl->gl_name, name))
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continue;
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if (gl->gl_sbd != sdp)
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continue;
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atomic_inc(&gl->gl_ref);
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return gl;
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}
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return NULL;
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}
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/**
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* gfs2_glock_find() - Find glock by lock number
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* @sdp: The GFS2 superblock
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* @name: The lock name
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*
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* Returns: NULL, or the struct gfs2_glock with the requested number
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*/
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static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp,
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const struct lm_lockname *name)
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{
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unsigned int hash = gl_hash(sdp, name);
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struct gfs2_glock *gl;
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read_lock(gl_lock_addr(hash));
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gl = search_bucket(hash, sdp, name);
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read_unlock(gl_lock_addr(hash));
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return gl;
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}
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/**
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* may_grant - check if its ok to grant a new lock
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* @gl: The glock
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* @gh: The lock request which we wish to grant
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*
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* Returns: true if its ok to grant the lock
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*/
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static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
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{
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const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
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if ((gh->gh_state == LM_ST_EXCLUSIVE ||
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gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
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return 0;
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if (gl->gl_state == gh->gh_state)
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return 1;
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if (gh->gh_flags & GL_EXACT)
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return 0;
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if (gl->gl_state == LM_ST_EXCLUSIVE) {
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if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
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return 1;
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if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
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return 1;
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}
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if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
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return 1;
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return 0;
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}
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static void gfs2_holder_wake(struct gfs2_holder *gh)
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{
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clear_bit(HIF_WAIT, &gh->gh_iflags);
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smp_mb__after_clear_bit();
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wake_up_bit(&gh->gh_iflags, HIF_WAIT);
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}
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/**
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* do_promote - promote as many requests as possible on the current queue
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* @gl: The glock
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*
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* Returns: true if there is a blocked holder at the head of the list
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*/
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static int do_promote(struct gfs2_glock *gl)
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{
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const struct gfs2_glock_operations *glops = gl->gl_ops;
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struct gfs2_holder *gh, *tmp;
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int ret;
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restart:
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list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
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if (test_bit(HIF_HOLDER, &gh->gh_iflags))
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continue;
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if (may_grant(gl, gh)) {
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if (gh->gh_list.prev == &gl->gl_holders &&
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glops->go_lock) {
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spin_unlock(&gl->gl_spin);
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/* FIXME: eliminate this eventually */
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ret = glops->go_lock(gh);
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spin_lock(&gl->gl_spin);
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if (ret) {
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gh->gh_error = ret;
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list_del_init(&gh->gh_list);
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gfs2_holder_wake(gh);
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goto restart;
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}
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set_bit(HIF_HOLDER, &gh->gh_iflags);
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gfs2_holder_wake(gh);
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goto restart;
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}
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set_bit(HIF_HOLDER, &gh->gh_iflags);
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gfs2_holder_wake(gh);
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continue;
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}
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if (gh->gh_list.prev == &gl->gl_holders)
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return 1;
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break;
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}
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return 0;
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}
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/**
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* do_error - Something unexpected has happened during a lock request
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*
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*/
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static inline void do_error(struct gfs2_glock *gl, const int ret)
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{
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struct gfs2_holder *gh, *tmp;
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list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
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if (test_bit(HIF_HOLDER, &gh->gh_iflags))
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continue;
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if (ret & LM_OUT_ERROR)
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gh->gh_error = -EIO;
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else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
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gh->gh_error = GLR_TRYFAILED;
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else
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continue;
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list_del_init(&gh->gh_list);
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gfs2_holder_wake(gh);
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}
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}
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/**
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* find_first_waiter - find the first gh that's waiting for the glock
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* @gl: the glock
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*/
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static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
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{
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struct gfs2_holder *gh;
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list_for_each_entry(gh, &gl->gl_holders, gh_list) {
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if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
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return gh;
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}
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return NULL;
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}
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/**
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* state_change - record that the glock is now in a different state
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* @gl: the glock
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* @new_state the new state
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*
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*/
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static void state_change(struct gfs2_glock *gl, unsigned int new_state)
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{
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int held1, held2;
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held1 = (gl->gl_state != LM_ST_UNLOCKED);
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held2 = (new_state != LM_ST_UNLOCKED);
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if (held1 != held2) {
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if (held2)
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gfs2_glock_hold(gl);
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else
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gfs2_glock_put(gl);
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}
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gl->gl_state = new_state;
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gl->gl_tchange = jiffies;
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}
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static void gfs2_demote_wake(struct gfs2_glock *gl)
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{
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gl->gl_demote_state = LM_ST_EXCLUSIVE;
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clear_bit(GLF_DEMOTE, &gl->gl_flags);
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smp_mb__after_clear_bit();
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wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
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}
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/**
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* finish_xmote - The DLM has replied to one of our lock requests
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* @gl: The glock
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* @ret: The status from the DLM
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*
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*/
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static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
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{
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const struct gfs2_glock_operations *glops = gl->gl_ops;
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struct gfs2_holder *gh;
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unsigned state = ret & LM_OUT_ST_MASK;
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spin_lock(&gl->gl_spin);
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state_change(gl, state);
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gh = find_first_waiter(gl);
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/* Demote to UN request arrived during demote to SH or DF */
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if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
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state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
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gl->gl_target = LM_ST_UNLOCKED;
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/* Check for state != intended state */
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if (unlikely(state != gl->gl_target)) {
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if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
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/* move to back of queue and try next entry */
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if (ret & LM_OUT_CANCELED) {
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if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
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list_move_tail(&gh->gh_list, &gl->gl_holders);
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gh = find_first_waiter(gl);
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gl->gl_target = gh->gh_state;
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goto retry;
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}
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/* Some error or failed "try lock" - report it */
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if ((ret & LM_OUT_ERROR) ||
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(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
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gl->gl_target = gl->gl_state;
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do_error(gl, ret);
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goto out;
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}
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}
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switch(state) {
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/* Unlocked due to conversion deadlock, try again */
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case LM_ST_UNLOCKED:
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retry:
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do_xmote(gl, gh, gl->gl_target);
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break;
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/* Conversion fails, unlock and try again */
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case LM_ST_SHARED:
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case LM_ST_DEFERRED:
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do_xmote(gl, gh, LM_ST_UNLOCKED);
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break;
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default: /* Everything else */
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printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
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GLOCK_BUG_ON(gl, 1);
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}
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spin_unlock(&gl->gl_spin);
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gfs2_glock_put(gl);
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return;
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}
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/* Fast path - we got what we asked for */
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if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
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gfs2_demote_wake(gl);
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if (state != LM_ST_UNLOCKED) {
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if (glops->go_xmote_bh) {
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int rv;
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spin_unlock(&gl->gl_spin);
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rv = glops->go_xmote_bh(gl, gh);
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if (rv == -EAGAIN)
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return;
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spin_lock(&gl->gl_spin);
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if (rv) {
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do_error(gl, rv);
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goto out;
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}
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}
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do_promote(gl);
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}
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out:
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clear_bit(GLF_LOCK, &gl->gl_flags);
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spin_unlock(&gl->gl_spin);
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gfs2_glock_put(gl);
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}
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static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock,
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unsigned int cur_state, unsigned int req_state,
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unsigned int flags)
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{
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int ret = LM_OUT_ERROR;
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if (!sdp->sd_lockstruct.ls_ops->lm_lock)
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return req_state == LM_ST_UNLOCKED ? 0 : req_state;
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|
|
|
if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
|
|
ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, cur_state,
|
|
req_state, flags);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
const struct gfs2_glock_operations *glops = gl->gl_ops;
|
|
struct gfs2_sbd *sdp = gl->gl_sbd;
|
|
unsigned int lck_flags = gh ? gh->gh_flags : 0;
|
|
int ret;
|
|
|
|
lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
|
|
LM_FLAG_PRIORITY);
|
|
BUG_ON(gl->gl_state == target);
|
|
BUG_ON(gl->gl_state == gl->gl_target);
|
|
if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
|
|
glops->go_inval) {
|
|
set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
|
|
do_error(gl, 0); /* Fail queued try locks */
|
|
}
|
|
spin_unlock(&gl->gl_spin);
|
|
if (glops->go_xmote_th)
|
|
glops->go_xmote_th(gl);
|
|
if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
|
|
glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
|
|
clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
|
|
|
|
gfs2_glock_hold(gl);
|
|
if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED ||
|
|
gl->gl_state == LM_ST_DEFERRED) &&
|
|
!(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
|
|
lck_flags |= LM_FLAG_TRY_1CB;
|
|
ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, target, lck_flags);
|
|
|
|
if (!(ret & LM_OUT_ASYNC)) {
|
|
finish_xmote(gl, ret);
|
|
gfs2_glock_hold(gl);
|
|
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
|
|
gfs2_glock_put(gl);
|
|
} else {
|
|
GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC);
|
|
}
|
|
spin_lock(&gl->gl_spin);
|
|
}
|
|
|
|
/**
|
|
* find_first_holder - find the first "holder" gh
|
|
* @gl: the glock
|
|
*/
|
|
|
|
static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
|
|
{
|
|
struct gfs2_holder *gh;
|
|
|
|
if (!list_empty(&gl->gl_holders)) {
|
|
gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
|
|
if (test_bit(HIF_HOLDER, &gh->gh_iflags))
|
|
return gh;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* run_queue - do all outstanding tasks related to a glock
|
|
* @gl: The glock in question
|
|
* @nonblock: True if we must not block in run_queue
|
|
*
|
|
*/
|
|
|
|
static void run_queue(struct gfs2_glock *gl, const int nonblock)
|
|
{
|
|
struct gfs2_holder *gh = NULL;
|
|
|
|
if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
|
|
return;
|
|
|
|
GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
|
|
|
|
if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
|
|
gl->gl_demote_state != gl->gl_state) {
|
|
if (find_first_holder(gl))
|
|
goto out;
|
|
if (nonblock)
|
|
goto out_sched;
|
|
set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
|
|
GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
|
|
gl->gl_target = gl->gl_demote_state;
|
|
} else {
|
|
if (test_bit(GLF_DEMOTE, &gl->gl_flags))
|
|
gfs2_demote_wake(gl);
|
|
if (do_promote(gl) == 0)
|
|
goto out;
|
|
gh = find_first_waiter(gl);
|
|
gl->gl_target = gh->gh_state;
|
|
if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
|
|
do_error(gl, 0); /* Fail queued try locks */
|
|
}
|
|
do_xmote(gl, gh, gl->gl_target);
|
|
return;
|
|
|
|
out_sched:
|
|
gfs2_glock_hold(gl);
|
|
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
|
|
gfs2_glock_put(gl);
|
|
out:
|
|
clear_bit(GLF_LOCK, &gl->gl_flags);
|
|
}
|
|
|
|
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);
|
|
|
|
if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags))
|
|
finish_xmote(gl, gl->gl_reply);
|
|
spin_lock(&gl->gl_spin);
|
|
if (test_and_clear_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_ops->go_min_hold_time;
|
|
if (time_before(now, holdtime))
|
|
delay = holdtime - now;
|
|
set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags);
|
|
}
|
|
run_queue(gl, 0);
|
|
spin_unlock(&gl->gl_spin);
|
|
if (!delay ||
|
|
queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
|
|
gfs2_glock_put(gl);
|
|
}
|
|
|
|
static int gfs2_lm_get_lock(struct gfs2_sbd *sdp, struct lm_lockname *name,
|
|
void **lockp)
|
|
{
|
|
int error = -EIO;
|
|
if (!sdp->sd_lockstruct.ls_ops->lm_get_lock)
|
|
return 0;
|
|
if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
|
|
error = sdp->sd_lockstruct.ls_ops->lm_get_lock(
|
|
sdp->sd_lockstruct.ls_lockspace, name, lockp);
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* 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_target = LM_ST_UNLOCKED;
|
|
gl->gl_demote_state = LM_ST_EXCLUSIVE;
|
|
gl->gl_hash = hash;
|
|
gl->gl_ops = glops;
|
|
gl->gl_stamp = jiffies;
|
|
gl->gl_tchange = jiffies;
|
|
gl->gl_object = NULL;
|
|
gl->gl_sbd = sdp;
|
|
gl->gl_aspace = NULL;
|
|
INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
|
|
|
|
/* 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 = get_pid(task_pid(current));
|
|
gh->gh_state = state;
|
|
gh->gh_flags = flags;
|
|
gh->gh_error = 0;
|
|
gh->gh_iflags = 0;
|
|
gfs2_glock_hold(gl);
|
|
}
|
|
|
|
/**
|
|
* gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
|
|
* @state: the state we're requesting
|
|
* @flags: the modifier flags
|
|
* @gh: the holder structure
|
|
*
|
|
* Don't mess with the glock.
|
|
*
|
|
*/
|
|
|
|
void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
|
|
{
|
|
gh->gh_state = state;
|
|
gh->gh_flags = flags;
|
|
gh->gh_iflags = 0;
|
|
gh->gh_ip = (unsigned long)__builtin_return_address(0);
|
|
}
|
|
|
|
/**
|
|
* gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
|
|
* @gh: the holder structure
|
|
*
|
|
*/
|
|
|
|
void gfs2_holder_uninit(struct gfs2_holder *gh)
|
|
{
|
|
put_pid(gh->gh_owner_pid);
|
|
gfs2_glock_put(gh->gh_gl);
|
|
gh->gh_gl = NULL;
|
|
gh->gh_ip = 0;
|
|
}
|
|
|
|
static int just_schedule(void *word)
|
|
{
|
|
schedule();
|
|
return 0;
|
|
}
|
|
|
|
static void wait_on_holder(struct gfs2_holder *gh)
|
|
{
|
|
might_sleep();
|
|
wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE);
|
|
}
|
|
|
|
static void wait_on_demote(struct gfs2_glock *gl)
|
|
{
|
|
might_sleep();
|
|
wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE);
|
|
}
|
|
|
|
/**
|
|
* 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,
|
|
int remote, unsigned long delay)
|
|
{
|
|
int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
|
|
|
|
set_bit(bit, &gl->gl_flags);
|
|
if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
|
|
gl->gl_demote_state = state;
|
|
gl->gl_demote_time = jiffies;
|
|
if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN &&
|
|
gl->gl_object)
|
|
gfs2_glock_schedule_for_reclaim(gl);
|
|
} else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
|
|
gl->gl_demote_state != state) {
|
|
gl->gl_demote_state = LM_ST_UNLOCKED;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gfs2_glock_wait - wait on a glock acquisition
|
|
* @gh: the glock holder
|
|
*
|
|
* Returns: 0 on success
|
|
*/
|
|
|
|
int gfs2_glock_wait(struct gfs2_holder *gh)
|
|
{
|
|
wait_on_holder(gh);
|
|
return gh->gh_error;
|
|
}
|
|
|
|
void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
|
|
va_start(args, fmt);
|
|
if (seq) {
|
|
struct gfs2_glock_iter *gi = seq->private;
|
|
vsprintf(gi->string, fmt, args);
|
|
seq_printf(seq, gi->string);
|
|
} else {
|
|
printk(KERN_ERR " ");
|
|
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
|
|
*
|
|
* 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)
|
|
{
|
|
struct gfs2_glock *gl = gh->gh_gl;
|
|
struct gfs2_sbd *sdp = gl->gl_sbd;
|
|
struct list_head *insert_pt = NULL;
|
|
struct gfs2_holder *gh2;
|
|
int try_lock = 0;
|
|
|
|
BUG_ON(gh->gh_owner_pid == NULL);
|
|
if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
|
|
BUG();
|
|
|
|
if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
|
|
if (test_bit(GLF_LOCK, &gl->gl_flags))
|
|
try_lock = 1;
|
|
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_lock &&
|
|
!(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
|
|
!may_grant(gl, gh)) {
|
|
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;
|
|
}
|
|
if (likely(insert_pt == NULL)) {
|
|
list_add_tail(&gh->gh_list, &gl->gl_holders);
|
|
if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
|
|
goto do_cancel;
|
|
return;
|
|
}
|
|
list_add_tail(&gh->gh_list, insert_pt);
|
|
do_cancel:
|
|
gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
|
|
if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
|
|
spin_unlock(&gl->gl_spin);
|
|
if (sdp->sd_lockstruct.ls_ops->lm_cancel)
|
|
sdp->sd_lockstruct.ls_ops->lm_cancel(gl->gl_lock);
|
|
spin_lock(&gl->gl_spin);
|
|
}
|
|
return;
|
|
|
|
trap_recursive:
|
|
print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip);
|
|
printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
|
|
printk(KERN_ERR "lock type: %d req lock state : %d\n",
|
|
gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
|
|
print_symbol(KERN_ERR "new: %s\n", gh->gh_ip);
|
|
printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
|
|
printk(KERN_ERR "lock type: %d req lock state : %d\n",
|
|
gh->gh_gl->gl_name.ln_type, gh->gh_state);
|
|
__dump_glock(NULL, gl);
|
|
BUG();
|
|
}
|
|
|
|
/**
|
|
* gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
|
|
* @gh: the holder structure
|
|
*
|
|
* if (gh->gh_flags & GL_ASYNC), this never returns an error
|
|
*
|
|
* Returns: 0, GLR_TRYFAILED, or errno on failure
|
|
*/
|
|
|
|
int gfs2_glock_nq(struct gfs2_holder *gh)
|
|
{
|
|
struct gfs2_glock *gl = gh->gh_gl;
|
|
struct gfs2_sbd *sdp = gl->gl_sbd;
|
|
int error = 0;
|
|
|
|
if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
|
|
return -EIO;
|
|
|
|
spin_lock(&gl->gl_spin);
|
|
add_to_queue(gh);
|
|
run_queue(gl, 1);
|
|
spin_unlock(&gl->gl_spin);
|
|
|
|
if (!(gh->gh_flags & GL_ASYNC))
|
|
error = gfs2_glock_wait(gh);
|
|
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* gfs2_glock_poll - poll to see if an async request has been completed
|
|
* @gh: the holder
|
|
*
|
|
* Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
|
|
*/
|
|
|
|
int gfs2_glock_poll(struct gfs2_holder *gh)
|
|
{
|
|
return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
|
|
}
|
|
|
|
/**
|
|
* gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
|
|
* @gh: the glock holder
|
|
*
|
|
*/
|
|
|
|
void gfs2_glock_dq(struct gfs2_holder *gh)
|
|
{
|
|
struct gfs2_glock *gl = gh->gh_gl;
|
|
const struct gfs2_glock_operations *glops = gl->gl_ops;
|
|
unsigned delay = 0;
|
|
int fast_path = 0;
|
|
|
|
spin_lock(&gl->gl_spin);
|
|
if (gh->gh_flags & GL_NOCACHE)
|
|
handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
|
|
|
|
list_del_init(&gh->gh_list);
|
|
if (find_first_holder(gl) == NULL) {
|
|
if (glops->go_unlock) {
|
|
GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
|
|
spin_unlock(&gl->gl_spin);
|
|
glops->go_unlock(gh);
|
|
spin_lock(&gl->gl_spin);
|
|
clear_bit(GLF_LOCK, &gl->gl_flags);
|
|
}
|
|
gl->gl_stamp = jiffies;
|
|
if (list_empty(&gl->gl_holders) &&
|
|
!test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
|
|
!test_bit(GLF_DEMOTE, &gl->gl_flags))
|
|
fast_path = 1;
|
|
}
|
|
spin_unlock(&gl->gl_spin);
|
|
if (likely(fast_path))
|
|
return;
|
|
|
|
gfs2_glock_hold(gl);
|
|
if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
|
|
!test_bit(GLF_DEMOTE, &gl->gl_flags))
|
|
delay = gl->gl_ops->go_min_hold_time;
|
|
if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
|
|
gfs2_glock_put(gl);
|
|
}
|
|
|
|
void gfs2_glock_dq_wait(struct gfs2_holder *gh)
|
|
{
|
|
struct gfs2_glock *gl = gh->gh_gl;
|
|
gfs2_glock_dq(gh);
|
|
wait_on_demote(gl);
|
|
}
|
|
|
|
/**
|
|
* 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
|
|
*
|
|
*
|
|
* Returns: 0 on success (all glocks acquired),
|
|
* errno on failure (no glocks acquired)
|
|
*/
|
|
|
|
int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
|
|
{
|
|
struct gfs2_holder *tmp[4];
|
|
struct gfs2_holder **pph = tmp;
|
|
int error = 0;
|
|
|
|
switch(num_gh) {
|
|
case 0:
|
|
return 0;
|
|
case 1:
|
|
ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
|
|
return gfs2_glock_nq(ghs);
|
|
default:
|
|
if (num_gh <= 4)
|
|
break;
|
|
pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
|
|
if (!pph)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
error = nq_m_sync(num_gh, ghs, pph);
|
|
|
|
if (pph != tmp)
|
|
kfree(pph);
|
|
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* gfs2_glock_dq_m - release multiple glocks
|
|
* @num_gh: the number of structures
|
|
* @ghs: an array of struct gfs2_holder structures
|
|
*
|
|
*/
|
|
|
|
void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
|
|
{
|
|
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]);
|
|
}
|
|
|
|
static int gfs2_lm_hold_lvb(struct gfs2_sbd *sdp, void *lock, char **lvbp)
|
|
{
|
|
int error = -EIO;
|
|
if (!sdp->sd_lockstruct.ls_ops->lm_hold_lvb)
|
|
return 0;
|
|
if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
|
|
error = sdp->sd_lockstruct.ls_ops->lm_hold_lvb(lock, lvbp);
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* gfs2_lvb_hold - attach a LVB from a glock
|
|
* @gl: The glock in question
|
|
*
|
|
*/
|
|
|
|
int gfs2_lvb_hold(struct gfs2_glock *gl)
|
|
{
|
|
int error;
|
|
|
|
if (!atomic_read(&gl->gl_lvb_count)) {
|
|
error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb);
|
|
if (error)
|
|
return error;
|
|
gfs2_glock_hold(gl);
|
|
}
|
|
atomic_inc(&gl->gl_lvb_count);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* gfs2_lvb_unhold - detach a LVB from a glock
|
|
* @gl: The glock in question
|
|
*
|
|
*/
|
|
|
|
void gfs2_lvb_unhold(struct gfs2_glock *gl)
|
|
{
|
|
struct gfs2_sbd *sdp = gl->gl_sbd;
|
|
|
|
gfs2_glock_hold(gl);
|
|
gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0);
|
|
if (atomic_dec_and_test(&gl->gl_lvb_count)) {
|
|
if (sdp->sd_lockstruct.ls_ops->lm_unhold_lvb)
|
|
sdp->sd_lockstruct.ls_ops->lm_unhold_lvb(gl->gl_lock, gl->gl_lvb);
|
|
gl->gl_lvb = NULL;
|
|
gfs2_glock_put(gl);
|
|
}
|
|
gfs2_glock_put(gl);
|
|
}
|
|
|
|
static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
|
|
unsigned int state)
|
|
{
|
|
struct gfs2_glock *gl;
|
|
unsigned long delay = 0;
|
|
unsigned long holdtime;
|
|
unsigned long now = jiffies;
|
|
|
|
gl = gfs2_glock_find(sdp, name);
|
|
if (!gl)
|
|
return;
|
|
|
|
holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
|
|
if (time_before(now, holdtime))
|
|
delay = holdtime - now;
|
|
if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
|
|
delay = gl->gl_ops->go_min_hold_time;
|
|
|
|
spin_lock(&gl->gl_spin);
|
|
handle_callback(gl, state, 1, delay);
|
|
spin_unlock(&gl->gl_spin);
|
|
if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
|
|
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;
|
|
gl->gl_reply = async->lc_ret;
|
|
set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
|
|
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
|
|
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;
|
|
|
|
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);
|
|
} else
|
|
spin_unlock(&sdp->sd_reclaim_lock);
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
int done_callback = 0;
|
|
|
|
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);
|
|
|
|
spin_lock(&gl->gl_spin);
|
|
if (find_first_holder(gl) == NULL &&
|
|
gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) {
|
|
handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
|
|
done_callback = 1;
|
|
}
|
|
spin_unlock(&gl->gl_spin);
|
|
if (!done_callback ||
|
|
queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
|
|
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 (!sdp || 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);
|
|
cond_resched();
|
|
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 (test_bit(GLF_LOCK, &gl->gl_flags))
|
|
return;
|
|
|
|
spin_lock(&gl->gl_spin);
|
|
if (find_first_holder(gl) == NULL &&
|
|
gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
|
|
gfs2_glock_schedule_for_reclaim(gl);
|
|
spin_unlock(&gl->gl_spin);
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
}
|
|
|
|
spin_lock(&gl->gl_spin);
|
|
if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED)
|
|
handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
|
|
spin_unlock(&gl->gl_spin);
|
|
gfs2_glock_hold(gl);
|
|
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
|
|
gfs2_glock_put(gl);
|
|
}
|
|
|
|
/**
|
|
* gfs2_gl_hash_clear - Empty out the glock hash table
|
|
* @sdp: the filesystem
|
|
* @wait: wait until it's all gone
|
|
*
|
|
* Called when unmounting the filesystem.
|
|
*/
|
|
|
|
void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
|
|
{
|
|
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 (!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);
|
|
}
|
|
}
|
|
|
|
static const char *state2str(unsigned state)
|
|
{
|
|
switch(state) {
|
|
case LM_ST_UNLOCKED:
|
|
return "UN";
|
|
case LM_ST_SHARED:
|
|
return "SH";
|
|
case LM_ST_DEFERRED:
|
|
return "DF";
|
|
case LM_ST_EXCLUSIVE:
|
|
return "EX";
|
|
}
|
|
return "??";
|
|
}
|
|
|
|
static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
|
|
{
|
|
char *p = buf;
|
|
if (flags & LM_FLAG_TRY)
|
|
*p++ = 't';
|
|
if (flags & LM_FLAG_TRY_1CB)
|
|
*p++ = 'T';
|
|
if (flags & LM_FLAG_NOEXP)
|
|
*p++ = 'e';
|
|
if (flags & LM_FLAG_ANY)
|
|
*p++ = 'a';
|
|
if (flags & LM_FLAG_PRIORITY)
|
|
*p++ = 'p';
|
|
if (flags & GL_ASYNC)
|
|
*p++ = 'a';
|
|
if (flags & GL_EXACT)
|
|
*p++ = 'E';
|
|
if (flags & GL_ATIME)
|
|
*p++ = 'a';
|
|
if (flags & GL_NOCACHE)
|
|
*p++ = 'c';
|
|
if (test_bit(HIF_HOLDER, &iflags))
|
|
*p++ = 'H';
|
|
if (test_bit(HIF_WAIT, &iflags))
|
|
*p++ = 'W';
|
|
if (test_bit(HIF_FIRST, &iflags))
|
|
*p++ = 'F';
|
|
*p = 0;
|
|
return buf;
|
|
}
|
|
|
|
/**
|
|
* dump_holder - print information about a glock holder
|
|
* @seq: the seq_file struct
|
|
* @gh: the glock holder
|
|
*
|
|
* Returns: 0 on success, -ENOBUFS when we run out of space
|
|
*/
|
|
|
|
static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
|
|
{
|
|
struct task_struct *gh_owner = NULL;
|
|
char buffer[KSYM_SYMBOL_LEN];
|
|
char flags_buf[32];
|
|
|
|
sprint_symbol(buffer, gh->gh_ip);
|
|
if (gh->gh_owner_pid)
|
|
gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
|
|
gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n",
|
|
state2str(gh->gh_state),
|
|
hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
|
|
gh->gh_error,
|
|
gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
|
|
gh_owner ? gh_owner->comm : "(ended)", buffer);
|
|
return 0;
|
|
}
|
|
|
|
static const char *gflags2str(char *buf, const unsigned long *gflags)
|
|
{
|
|
char *p = buf;
|
|
if (test_bit(GLF_LOCK, gflags))
|
|
*p++ = 'l';
|
|
if (test_bit(GLF_STICKY, gflags))
|
|
*p++ = 's';
|
|
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';
|
|
*p = 0;
|
|
return buf;
|
|
}
|
|
|
|
/**
|
|
* __dump_glock - print information about a glock
|
|
* @seq: The seq_file struct
|
|
* @gl: the glock
|
|
*
|
|
* The file format is as follows:
|
|
* One line per object, capital letters are used to indicate objects
|
|
* G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
|
|
* other objects are indented by a single space and follow the glock to
|
|
* which they are related. Fields are indicated by lower case letters
|
|
* followed by a colon and the field value, except for strings which are in
|
|
* [] so that its possible to see if they are composed of spaces for
|
|
* example. The field's are n = number (id of the object), f = flags,
|
|
* t = type, s = state, r = refcount, e = error, p = pid.
|
|
*
|
|
* Returns: 0 on success, -ENOBUFS when we run out of space
|
|
*/
|
|
|
|
static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
|
|
{
|
|
const struct gfs2_glock_operations *glops = gl->gl_ops;
|
|
unsigned long long dtime;
|
|
const struct gfs2_holder *gh;
|
|
char gflags_buf[32];
|
|
int error = 0;
|
|
|
|
dtime = jiffies - gl->gl_demote_time;
|
|
dtime *= 1000000/HZ; /* demote time in uSec */
|
|
if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
|
|
dtime = 0;
|
|
gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu l:%d a:%d r:%d\n",
|
|
state2str(gl->gl_state),
|
|
gl->gl_name.ln_type,
|
|
(unsigned long long)gl->gl_name.ln_number,
|
|
gflags2str(gflags_buf, &gl->gl_flags),
|
|
state2str(gl->gl_target),
|
|
state2str(gl->gl_demote_state), dtime,
|
|
atomic_read(&gl->gl_lvb_count),
|
|
atomic_read(&gl->gl_ail_count),
|
|
atomic_read(&gl->gl_ref));
|
|
|
|
list_for_each_entry(gh, &gl->gl_holders, gh_list) {
|
|
error = dump_holder(seq, gh);
|
|
if (error)
|
|
goto out;
|
|
}
|
|
if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
|
|
error = glops->go_dump(seq, gl);
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
|
|
{
|
|
int ret;
|
|
spin_lock(&gl->gl_spin);
|
|
ret = __dump_glock(seq, gl);
|
|
spin_unlock(&gl->gl_spin);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
}
|
|
|
|
/**
|
|
* gfs2_scand - Look for cached glocks and inodes to toss from memory
|
|
* @sdp: Pointer to GFS2 superblock
|
|
*
|
|
* One of these daemons runs, finding candidates to add to sd_reclaim_list.
|
|
* See gfs2_glockd()
|
|
*/
|
|
|
|
static int gfs2_scand(void *data)
|
|
{
|
|
unsigned x;
|
|
unsigned delay;
|
|
|
|
while (!kthread_should_stop()) {
|
|
for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
|
|
examine_bucket(scan_glock, NULL, x);
|
|
if (freezing(current))
|
|
refrigerator();
|
|
delay = scand_secs;
|
|
if (delay < 1)
|
|
delay = 1;
|
|
schedule_timeout_interruptible(delay * HZ);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
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
|
|
|
|
scand_process = kthread_run(gfs2_scand, NULL, "gfs2_scand");
|
|
if (IS_ERR(scand_process))
|
|
return PTR_ERR(scand_process);
|
|
|
|
glock_workqueue = create_workqueue("glock_workqueue");
|
|
if (IS_ERR(glock_workqueue)) {
|
|
kthread_stop(scand_process);
|
|
return PTR_ERR(glock_workqueue);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void gfs2_glock_exit(void)
|
|
{
|
|
destroy_workqueue(glock_workqueue);
|
|
kthread_stop(scand_process);
|
|
}
|
|
|
|
module_param(scand_secs, uint, S_IRUGO|S_IWUSR);
|
|
MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs");
|
|
|
|
static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
|
|
{
|
|
struct gfs2_glock *gl;
|
|
|
|
restart:
|
|
read_lock(gl_lock_addr(gi->hash));
|
|
gl = gi->gl;
|
|
if (gl) {
|
|
gi->gl = hlist_entry(gl->gl_list.next,
|
|
struct gfs2_glock, gl_list);
|
|
} else {
|
|
gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
|
|
struct gfs2_glock, gl_list);
|
|
}
|
|
if (gi->gl)
|
|
gfs2_glock_hold(gi->gl);
|
|
read_unlock(gl_lock_addr(gi->hash));
|
|
if (gl)
|
|
gfs2_glock_put(gl);
|
|
while (gi->gl == NULL) {
|
|
gi->hash++;
|
|
if (gi->hash >= GFS2_GL_HASH_SIZE)
|
|
return 1;
|
|
read_lock(gl_lock_addr(gi->hash));
|
|
gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
|
|
struct gfs2_glock, gl_list);
|
|
if (gi->gl)
|
|
gfs2_glock_hold(gi->gl);
|
|
read_unlock(gl_lock_addr(gi->hash));
|
|
}
|
|
|
|
if (gi->sdp != gi->gl->gl_sbd)
|
|
goto restart;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi)
|
|
{
|
|
if (gi->gl)
|
|
gfs2_glock_put(gi->gl);
|
|
gi->gl = NULL;
|
|
}
|
|
|
|
static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
struct gfs2_glock_iter *gi = seq->private;
|
|
loff_t n = *pos;
|
|
|
|
gi->hash = 0;
|
|
|
|
do {
|
|
if (gfs2_glock_iter_next(gi)) {
|
|
gfs2_glock_iter_free(gi);
|
|
return NULL;
|
|
}
|
|
} while (n--);
|
|
|
|
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)++;
|
|
|
|
if (gfs2_glock_iter_next(gi)) {
|
|
gfs2_glock_iter_free(gi);
|
|
return NULL;
|
|
}
|
|
|
|
return gi->gl;
|
|
}
|
|
|
|
static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
|
|
{
|
|
struct gfs2_glock_iter *gi = seq->private;
|
|
gfs2_glock_iter_free(gi);
|
|
}
|
|
|
|
static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
|
|
{
|
|
return dump_glock(seq, iter_ptr);
|
|
}
|
|
|
|
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 int gfs2_debugfs_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret = seq_open_private(file, &gfs2_glock_seq_ops,
|
|
sizeof(struct gfs2_glock_iter));
|
|
if (ret == 0) {
|
|
struct seq_file *seq = file->private_data;
|
|
struct gfs2_glock_iter *gi = seq->private;
|
|
gi->sdp = inode->i_private;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations gfs2_debug_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = gfs2_debugfs_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release_private,
|
|
};
|
|
|
|
int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
|
|
{
|
|
sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
|
|
if (!sdp->debugfs_dir)
|
|
return -ENOMEM;
|
|
sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
|
|
S_IFREG | S_IRUGO,
|
|
sdp->debugfs_dir, sdp,
|
|
&gfs2_debug_fops);
|
|
if (!sdp->debugfs_dentry_glocks)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
|
|
{
|
|
if (sdp && sdp->debugfs_dir) {
|
|
if (sdp->debugfs_dentry_glocks) {
|
|
debugfs_remove(sdp->debugfs_dentry_glocks);
|
|
sdp->debugfs_dentry_glocks = NULL;
|
|
}
|
|
debugfs_remove(sdp->debugfs_dir);
|
|
sdp->debugfs_dir = NULL;
|
|
}
|
|
}
|
|
|
|
int gfs2_register_debugfs(void)
|
|
{
|
|
gfs2_root = debugfs_create_dir("gfs2", NULL);
|
|
return gfs2_root ? 0 : -ENOMEM;
|
|
}
|
|
|
|
void gfs2_unregister_debugfs(void)
|
|
{
|
|
debugfs_remove(gfs2_root);
|
|
gfs2_root = NULL;
|
|
}
|