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linux/fs/ocfs2/dlmglue.c
Arjan van de Ven 4b6f5d20b0 [PATCH] Make most file operations structs in fs/ const 
This is a conversion to make the various file_operations structs in fs/
const.  Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:06 -08:00

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/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* dlmglue.c
*
* Code which implements an OCFS2 specific interface to our DLM.
*
* Copyright (C) 2003, 2004 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/crc32.h>
#include <linux/kthread.h>
#include <linux/pagemap.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <cluster/heartbeat.h>
#include <cluster/nodemanager.h>
#include <cluster/tcp.h>
#include <dlm/dlmapi.h>
#define MLOG_MASK_PREFIX ML_DLM_GLUE
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "heartbeat.h"
#include "inode.h"
#include "journal.h"
#include "slot_map.h"
#include "super.h"
#include "uptodate.h"
#include "vote.h"
#include "buffer_head_io.h"
struct ocfs2_mask_waiter {
struct list_head mw_item;
int mw_status;
struct completion mw_complete;
unsigned long mw_mask;
unsigned long mw_goal;
};
static void ocfs2_inode_ast_func(void *opaque);
static void ocfs2_inode_bast_func(void *opaque,
int level);
static void ocfs2_super_ast_func(void *opaque);
static void ocfs2_super_bast_func(void *opaque,
int level);
static void ocfs2_rename_ast_func(void *opaque);
static void ocfs2_rename_bast_func(void *opaque,
int level);
/* so far, all locks have gotten along with the same unlock ast */
static void ocfs2_unlock_ast_func(void *opaque,
enum dlm_status status);
static int ocfs2_do_unblock_meta(struct inode *inode,
int *requeue);
static int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres,
int *requeue);
static int ocfs2_unblock_data(struct ocfs2_lock_res *lockres,
int *requeue);
static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres,
int *requeue);
static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres,
int *requeue);
typedef void (ocfs2_convert_worker_t)(struct ocfs2_lock_res *, int);
static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int *requeue,
ocfs2_convert_worker_t *worker);
struct ocfs2_lock_res_ops {
void (*ast)(void *);
void (*bast)(void *, int);
void (*unlock_ast)(void *, enum dlm_status);
int (*unblock)(struct ocfs2_lock_res *, int *);
};
static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
.ast = ocfs2_inode_ast_func,
.bast = ocfs2_inode_bast_func,
.unlock_ast = ocfs2_unlock_ast_func,
.unblock = ocfs2_unblock_inode_lock,
};
static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = {
.ast = ocfs2_inode_ast_func,
.bast = ocfs2_inode_bast_func,
.unlock_ast = ocfs2_unlock_ast_func,
.unblock = ocfs2_unblock_meta,
};
static void ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
int blocking);
static struct ocfs2_lock_res_ops ocfs2_inode_data_lops = {
.ast = ocfs2_inode_ast_func,
.bast = ocfs2_inode_bast_func,
.unlock_ast = ocfs2_unlock_ast_func,
.unblock = ocfs2_unblock_data,
};
static struct ocfs2_lock_res_ops ocfs2_super_lops = {
.ast = ocfs2_super_ast_func,
.bast = ocfs2_super_bast_func,
.unlock_ast = ocfs2_unlock_ast_func,
.unblock = ocfs2_unblock_osb_lock,
};
static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
.ast = ocfs2_rename_ast_func,
.bast = ocfs2_rename_bast_func,
.unlock_ast = ocfs2_unlock_ast_func,
.unblock = ocfs2_unblock_osb_lock,
};
static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
{
return lockres->l_type == OCFS2_LOCK_TYPE_META ||
lockres->l_type == OCFS2_LOCK_TYPE_DATA ||
lockres->l_type == OCFS2_LOCK_TYPE_RW;
}
static inline int ocfs2_is_super_lock(struct ocfs2_lock_res *lockres)
{
return lockres->l_type == OCFS2_LOCK_TYPE_SUPER;
}
static inline int ocfs2_is_rename_lock(struct ocfs2_lock_res *lockres)
{
return lockres->l_type == OCFS2_LOCK_TYPE_RENAME;
}
static inline struct ocfs2_super *ocfs2_lock_res_super(struct ocfs2_lock_res *lockres)
{
BUG_ON(!ocfs2_is_super_lock(lockres)
&& !ocfs2_is_rename_lock(lockres));
return (struct ocfs2_super *) lockres->l_priv;
}
static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
{
BUG_ON(!ocfs2_is_inode_lock(lockres));
return (struct inode *) lockres->l_priv;
}
static int ocfs2_lock_create(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int level,
int dlm_flags);
static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
int wanted);
static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int level);
static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres);
static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
int convert);
#define ocfs2_log_dlm_error(_func, _stat, _lockres) do { \
mlog(ML_ERROR, "Dlm error \"%s\" while calling %s on " \
"resource %s: %s\n", dlm_errname(_stat), _func, \
_lockres->l_name, dlm_errmsg(_stat)); \
} while (0)
static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres);
static int ocfs2_meta_lock_update(struct inode *inode,
struct buffer_head **bh);
static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
static inline int ocfs2_highest_compat_lock_level(int level);
static inline int ocfs2_can_downconvert_meta_lock(struct inode *inode,
struct ocfs2_lock_res *lockres,
int new_level);
static char *ocfs2_lock_type_strings[] = {
[OCFS2_LOCK_TYPE_META] = "Meta",
[OCFS2_LOCK_TYPE_DATA] = "Data",
[OCFS2_LOCK_TYPE_SUPER] = "Super",
[OCFS2_LOCK_TYPE_RENAME] = "Rename",
/* Need to differntiate from [R]ename.. serializing writes is the
* important job it does, anyway. */
[OCFS2_LOCK_TYPE_RW] = "Write/Read",
};
static char *ocfs2_lock_type_string(enum ocfs2_lock_type type)
{
mlog_bug_on_msg(type >= OCFS2_NUM_LOCK_TYPES, "%d\n", type);
return ocfs2_lock_type_strings[type];
}
static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
u64 blkno,
u32 generation,
char *name)
{
int len;
mlog_entry_void();
BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);
len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x",
ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
(long long)blkno, generation);
BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));
mlog(0, "built lock resource with name: %s\n", name);
mlog_exit_void();
}
static spinlock_t ocfs2_dlm_tracking_lock = SPIN_LOCK_UNLOCKED;
static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
struct ocfs2_dlm_debug *dlm_debug)
{
mlog(0, "Add tracking for lockres %s\n", res->l_name);
spin_lock(&ocfs2_dlm_tracking_lock);
list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
spin_unlock(&ocfs2_dlm_tracking_lock);
}
static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
{
spin_lock(&ocfs2_dlm_tracking_lock);
if (!list_empty(&res->l_debug_list))
list_del_init(&res->l_debug_list);
spin_unlock(&ocfs2_dlm_tracking_lock);
}
static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
struct ocfs2_lock_res *res,
enum ocfs2_lock_type type,
u64 blkno,
u32 generation,
struct ocfs2_lock_res_ops *ops,
void *priv)
{
ocfs2_build_lock_name(type, blkno, generation, res->l_name);
res->l_type = type;
res->l_ops = ops;
res->l_priv = priv;
res->l_level = LKM_IVMODE;
res->l_requested = LKM_IVMODE;
res->l_blocking = LKM_IVMODE;
res->l_action = OCFS2_AST_INVALID;
res->l_unlock_action = OCFS2_UNLOCK_INVALID;
res->l_flags = OCFS2_LOCK_INITIALIZED;
ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
}
void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
{
/* This also clears out the lock status block */
memset(res, 0, sizeof(struct ocfs2_lock_res));
spin_lock_init(&res->l_lock);
init_waitqueue_head(&res->l_event);
INIT_LIST_HEAD(&res->l_blocked_list);
INIT_LIST_HEAD(&res->l_mask_waiters);
}
void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
enum ocfs2_lock_type type,
struct inode *inode)
{
struct ocfs2_lock_res_ops *ops;
switch(type) {
case OCFS2_LOCK_TYPE_RW:
ops = &ocfs2_inode_rw_lops;
break;
case OCFS2_LOCK_TYPE_META:
ops = &ocfs2_inode_meta_lops;
break;
case OCFS2_LOCK_TYPE_DATA:
ops = &ocfs2_inode_data_lops;
break;
default:
mlog_bug_on_msg(1, "type: %d\n", type);
ops = NULL; /* thanks, gcc */
break;
};
ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type,
OCFS2_I(inode)->ip_blkno,
inode->i_generation, ops, inode);
}
static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
struct ocfs2_super *osb)
{
/* Superblock lockres doesn't come from a slab so we call init
* once on it manually. */
ocfs2_lock_res_init_once(res);
ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
OCFS2_SUPER_BLOCK_BLKNO, 0,
&ocfs2_super_lops, osb);
}
static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
struct ocfs2_super *osb)
{
/* Rename lockres doesn't come from a slab so we call init
* once on it manually. */
ocfs2_lock_res_init_once(res);
ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME, 0, 0,
&ocfs2_rename_lops, osb);
}
void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
{
mlog_entry_void();
if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
return;
ocfs2_remove_lockres_tracking(res);
mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
"Lockres %s is on the blocked list\n",
res->l_name);
mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
"Lockres %s has mask waiters pending\n",
res->l_name);
mlog_bug_on_msg(spin_is_locked(&res->l_lock),
"Lockres %s is locked\n",
res->l_name);
mlog_bug_on_msg(res->l_ro_holders,
"Lockres %s has %u ro holders\n",
res->l_name, res->l_ro_holders);
mlog_bug_on_msg(res->l_ex_holders,
"Lockres %s has %u ex holders\n",
res->l_name, res->l_ex_holders);
/* Need to clear out the lock status block for the dlm */
memset(&res->l_lksb, 0, sizeof(res->l_lksb));
res->l_flags = 0UL;
mlog_exit_void();
}
static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
int level)
{
mlog_entry_void();
BUG_ON(!lockres);
switch(level) {
case LKM_EXMODE:
lockres->l_ex_holders++;
break;
case LKM_PRMODE:
lockres->l_ro_holders++;
break;
default:
BUG();
}
mlog_exit_void();
}
static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
int level)
{
mlog_entry_void();
BUG_ON(!lockres);
switch(level) {
case LKM_EXMODE:
BUG_ON(!lockres->l_ex_holders);
lockres->l_ex_holders--;
break;
case LKM_PRMODE:
BUG_ON(!lockres->l_ro_holders);
lockres->l_ro_holders--;
break;
default:
BUG();
}
mlog_exit_void();
}
/* WARNING: This function lives in a world where the only three lock
* levels are EX, PR, and NL. It *will* have to be adjusted when more
* lock types are added. */
static inline int ocfs2_highest_compat_lock_level(int level)
{
int new_level = LKM_EXMODE;
if (level == LKM_EXMODE)
new_level = LKM_NLMODE;
else if (level == LKM_PRMODE)
new_level = LKM_PRMODE;
return new_level;
}
static void lockres_set_flags(struct ocfs2_lock_res *lockres,
unsigned long newflags)
{
struct list_head *pos, *tmp;
struct ocfs2_mask_waiter *mw;
assert_spin_locked(&lockres->l_lock);
lockres->l_flags = newflags;
list_for_each_safe(pos, tmp, &lockres->l_mask_waiters) {
mw = list_entry(pos, struct ocfs2_mask_waiter, mw_item);
if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
continue;
list_del_init(&mw->mw_item);
mw->mw_status = 0;
complete(&mw->mw_complete);
}
}
static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
{
lockres_set_flags(lockres, lockres->l_flags | or);
}
static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
unsigned long clear)
{
lockres_set_flags(lockres, lockres->l_flags & ~clear);
}
static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
{
mlog_entry_void();
BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
BUG_ON(lockres->l_blocking <= LKM_NLMODE);
lockres->l_level = lockres->l_requested;
if (lockres->l_level <=
ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
lockres->l_blocking = LKM_NLMODE;
lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
}
lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
mlog_exit_void();
}
static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
{
mlog_entry_void();
BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
/* Convert from RO to EX doesn't really need anything as our
* information is already up to data. Convert from NL to
* *anything* however should mark ourselves as needing an
* update */
if (lockres->l_level == LKM_NLMODE)
lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
lockres->l_level = lockres->l_requested;
lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
mlog_exit_void();
}
static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
{
mlog_entry_void();
BUG_ON((!lockres->l_flags & OCFS2_LOCK_BUSY));
BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
if (lockres->l_requested > LKM_NLMODE &&
!(lockres->l_flags & OCFS2_LOCK_LOCAL))
lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
lockres->l_level = lockres->l_requested;
lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
mlog_exit_void();
}
static void ocfs2_inode_ast_func(void *opaque)
{
struct ocfs2_lock_res *lockres = opaque;
struct inode *inode;
struct dlm_lockstatus *lksb;
unsigned long flags;
mlog_entry_void();
inode = ocfs2_lock_res_inode(lockres);
mlog(0, "AST fired for inode %llu, l_action = %u, type = %s\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno, lockres->l_action,
ocfs2_lock_type_string(lockres->l_type));
BUG_ON(!ocfs2_is_inode_lock(lockres));
spin_lock_irqsave(&lockres->l_lock, flags);
lksb = &(lockres->l_lksb);
if (lksb->status != DLM_NORMAL) {
mlog(ML_ERROR, "ocfs2_inode_ast_func: lksb status value of %u "
"on inode %llu\n", lksb->status,
(unsigned long long)OCFS2_I(inode)->ip_blkno);
spin_unlock_irqrestore(&lockres->l_lock, flags);
mlog_exit_void();
return;
}
switch(lockres->l_action) {
case OCFS2_AST_ATTACH:
ocfs2_generic_handle_attach_action(lockres);
lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
break;
case OCFS2_AST_CONVERT:
ocfs2_generic_handle_convert_action(lockres);
break;
case OCFS2_AST_DOWNCONVERT:
ocfs2_generic_handle_downconvert_action(lockres);
break;
default:
mlog(ML_ERROR, "lockres %s: ast fired with invalid action: %u "
"lockres flags = 0x%lx, unlock action: %u\n",
lockres->l_name, lockres->l_action, lockres->l_flags,
lockres->l_unlock_action);
BUG();
}
/* data and rw locking ignores refresh flag for now. */
if (lockres->l_type != OCFS2_LOCK_TYPE_META)
lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
/* set it to something invalid so if we get called again we
* can catch it. */
lockres->l_action = OCFS2_AST_INVALID;
spin_unlock_irqrestore(&lockres->l_lock, flags);
wake_up(&lockres->l_event);
mlog_exit_void();
}
static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
int level)
{
int needs_downconvert = 0;
mlog_entry_void();
assert_spin_locked(&lockres->l_lock);
lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
if (level > lockres->l_blocking) {
/* only schedule a downconvert if we haven't already scheduled
* one that goes low enough to satisfy the level we're
* blocking. this also catches the case where we get
* duplicate BASTs */
if (ocfs2_highest_compat_lock_level(level) <
ocfs2_highest_compat_lock_level(lockres->l_blocking))
needs_downconvert = 1;
lockres->l_blocking = level;
}
mlog_exit(needs_downconvert);
return needs_downconvert;
}
static void ocfs2_generic_bast_func(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int level)
{
int needs_downconvert;
unsigned long flags;
mlog_entry_void();
BUG_ON(level <= LKM_NLMODE);
spin_lock_irqsave(&lockres->l_lock, flags);
needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
if (needs_downconvert)
ocfs2_schedule_blocked_lock(osb, lockres);
spin_unlock_irqrestore(&lockres->l_lock, flags);
ocfs2_kick_vote_thread(osb);
wake_up(&lockres->l_event);
mlog_exit_void();
}
static void ocfs2_inode_bast_func(void *opaque, int level)
{
struct ocfs2_lock_res *lockres = opaque;
struct inode *inode;
struct ocfs2_super *osb;
mlog_entry_void();
BUG_ON(!ocfs2_is_inode_lock(lockres));
inode = ocfs2_lock_res_inode(lockres);
osb = OCFS2_SB(inode->i_sb);
mlog(0, "BAST fired for inode %llu, blocking %d, level %d type %s\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno, level,
lockres->l_level, ocfs2_lock_type_string(lockres->l_type));
ocfs2_generic_bast_func(osb, lockres, level);
mlog_exit_void();
}
static void ocfs2_generic_ast_func(struct ocfs2_lock_res *lockres,
int ignore_refresh)
{
struct dlm_lockstatus *lksb = &lockres->l_lksb;
unsigned long flags;
spin_lock_irqsave(&lockres->l_lock, flags);
if (lksb->status != DLM_NORMAL) {
mlog(ML_ERROR, "lockres %s: lksb status value of %u!\n",
lockres->l_name, lksb->status);
spin_unlock_irqrestore(&lockres->l_lock, flags);
return;
}
switch(lockres->l_action) {
case OCFS2_AST_ATTACH:
ocfs2_generic_handle_attach_action(lockres);
break;
case OCFS2_AST_CONVERT:
ocfs2_generic_handle_convert_action(lockres);
break;
case OCFS2_AST_DOWNCONVERT:
ocfs2_generic_handle_downconvert_action(lockres);
break;
default:
BUG();
}
if (ignore_refresh)
lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
/* set it to something invalid so if we get called again we
* can catch it. */
lockres->l_action = OCFS2_AST_INVALID;
spin_unlock_irqrestore(&lockres->l_lock, flags);
wake_up(&lockres->l_event);
}
static void ocfs2_super_ast_func(void *opaque)
{
struct ocfs2_lock_res *lockres = opaque;
mlog_entry_void();
mlog(0, "Superblock AST fired\n");
BUG_ON(!ocfs2_is_super_lock(lockres));
ocfs2_generic_ast_func(lockres, 0);
mlog_exit_void();
}
static void ocfs2_super_bast_func(void *opaque,
int level)
{
struct ocfs2_lock_res *lockres = opaque;
struct ocfs2_super *osb;
mlog_entry_void();
mlog(0, "Superblock BAST fired\n");
BUG_ON(!ocfs2_is_super_lock(lockres));
osb = ocfs2_lock_res_super(lockres);
ocfs2_generic_bast_func(osb, lockres, level);
mlog_exit_void();
}
static void ocfs2_rename_ast_func(void *opaque)
{
struct ocfs2_lock_res *lockres = opaque;
mlog_entry_void();
mlog(0, "Rename AST fired\n");
BUG_ON(!ocfs2_is_rename_lock(lockres));
ocfs2_generic_ast_func(lockres, 1);
mlog_exit_void();
}
static void ocfs2_rename_bast_func(void *opaque,
int level)
{
struct ocfs2_lock_res *lockres = opaque;
struct ocfs2_super *osb;
mlog_entry_void();
mlog(0, "Rename BAST fired\n");
BUG_ON(!ocfs2_is_rename_lock(lockres));
osb = ocfs2_lock_res_super(lockres);
ocfs2_generic_bast_func(osb, lockres, level);
mlog_exit_void();
}
static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
int convert)
{
unsigned long flags;
mlog_entry_void();
spin_lock_irqsave(&lockres->l_lock, flags);
lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
if (convert)
lockres->l_action = OCFS2_AST_INVALID;
else
lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
spin_unlock_irqrestore(&lockres->l_lock, flags);
wake_up(&lockres->l_event);
mlog_exit_void();
}
/* Note: If we detect another process working on the lock (i.e.,
* OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
* to do the right thing in that case.
*/
static int ocfs2_lock_create(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int level,
int dlm_flags)
{
int ret = 0;
enum dlm_status status;
unsigned long flags;
mlog_entry_void();
mlog(0, "lock %s, level = %d, flags = %d\n", lockres->l_name, level,
dlm_flags);
spin_lock_irqsave(&lockres->l_lock, flags);
if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
(lockres->l_flags & OCFS2_LOCK_BUSY)) {
spin_unlock_irqrestore(&lockres->l_lock, flags);
goto bail;
}
lockres->l_action = OCFS2_AST_ATTACH;
lockres->l_requested = level;
lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
spin_unlock_irqrestore(&lockres->l_lock, flags);
status = dlmlock(osb->dlm,
level,
&lockres->l_lksb,
dlm_flags,
lockres->l_name,
lockres->l_ops->ast,
lockres,
lockres->l_ops->bast);
if (status != DLM_NORMAL) {
ocfs2_log_dlm_error("dlmlock", status, lockres);
ret = -EINVAL;
ocfs2_recover_from_dlm_error(lockres, 1);
}
mlog(0, "lock %s, successfull return from dlmlock\n", lockres->l_name);
bail:
mlog_exit(ret);
return ret;
}
static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
int flag)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&lockres->l_lock, flags);
ret = lockres->l_flags & flag;
spin_unlock_irqrestore(&lockres->l_lock, flags);
return ret;
}
static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)
{
wait_event(lockres->l_event,
!ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
}
static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)
{
wait_event(lockres->l_event,
!ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
}
/* predict what lock level we'll be dropping down to on behalf
* of another node, and return true if the currently wanted
* level will be compatible with it. */
static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
int wanted)
{
BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
}
static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
{
INIT_LIST_HEAD(&mw->mw_item);
init_completion(&mw->mw_complete);
}
static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
{
wait_for_completion(&mw->mw_complete);
/* Re-arm the completion in case we want to wait on it again */
INIT_COMPLETION(mw->mw_complete);
return mw->mw_status;
}
static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
struct ocfs2_mask_waiter *mw,
unsigned long mask,
unsigned long goal)
{
BUG_ON(!list_empty(&mw->mw_item));
assert_spin_locked(&lockres->l_lock);
list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
mw->mw_mask = mask;
mw->mw_goal = goal;
}
/* returns 0 if the mw that was removed was already satisfied, -EBUSY
* if the mask still hadn't reached its goal */
static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
struct ocfs2_mask_waiter *mw)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&lockres->l_lock, flags);
if (!list_empty(&mw->mw_item)) {
if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
ret = -EBUSY;
list_del_init(&mw->mw_item);
init_completion(&mw->mw_complete);
}
spin_unlock_irqrestore(&lockres->l_lock, flags);
return ret;
}
static int ocfs2_cluster_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int level,
int lkm_flags,
int arg_flags)
{
struct ocfs2_mask_waiter mw;
enum dlm_status status;
int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
unsigned long flags;
mlog_entry_void();
ocfs2_init_mask_waiter(&mw);
again:
wait = 0;
if (catch_signals && signal_pending(current)) {
ret = -ERESTARTSYS;
goto out;
}
spin_lock_irqsave(&lockres->l_lock, flags);
mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
"Cluster lock called on freeing lockres %s! flags "
"0x%lx\n", lockres->l_name, lockres->l_flags);
/* We only compare against the currently granted level
* here. If the lock is blocked waiting on a downconvert,
* we'll get caught below. */
if (lockres->l_flags & OCFS2_LOCK_BUSY &&
level > lockres->l_level) {
/* is someone sitting in dlm_lock? If so, wait on
* them. */
lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
wait = 1;
goto unlock;
}
if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
/* lock has not been created yet. */
spin_unlock_irqrestore(&lockres->l_lock, flags);
ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
goto again;
}
if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
!ocfs2_may_continue_on_blocked_lock(lockres, level)) {
/* is the lock is currently blocked on behalf of
* another node */
lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
wait = 1;
goto unlock;
}
if (level > lockres->l_level) {
if (lockres->l_action != OCFS2_AST_INVALID)
mlog(ML_ERROR, "lockres %s has action %u pending\n",
lockres->l_name, lockres->l_action);
lockres->l_action = OCFS2_AST_CONVERT;
lockres->l_requested = level;
lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
spin_unlock_irqrestore(&lockres->l_lock, flags);
BUG_ON(level == LKM_IVMODE);
BUG_ON(level == LKM_NLMODE);
mlog(0, "lock %s, convert from %d to level = %d\n",
lockres->l_name, lockres->l_level, level);
/* call dlm_lock to upgrade lock now */
status = dlmlock(osb->dlm,
level,
&lockres->l_lksb,
lkm_flags|LKM_CONVERT|LKM_VALBLK,
lockres->l_name,
lockres->l_ops->ast,
lockres,
lockres->l_ops->bast);
if (status != DLM_NORMAL) {
if ((lkm_flags & LKM_NOQUEUE) &&
(status == DLM_NOTQUEUED))
ret = -EAGAIN;
else {
ocfs2_log_dlm_error("dlmlock", status,
lockres);
ret = -EINVAL;
}
ocfs2_recover_from_dlm_error(lockres, 1);
goto out;
}
mlog(0, "lock %s, successfull return from dlmlock\n",
lockres->l_name);
/* At this point we've gone inside the dlm and need to
* complete our work regardless. */
catch_signals = 0;
/* wait for busy to clear and carry on */
goto again;
}
/* Ok, if we get here then we're good to go. */
ocfs2_inc_holders(lockres, level);
ret = 0;
unlock:
spin_unlock_irqrestore(&lockres->l_lock, flags);
out:
/*
* This is helping work around a lock inversion between the page lock
* and dlm locks. One path holds the page lock while calling aops
* which block acquiring dlm locks. The voting thread holds dlm
* locks while acquiring page locks while down converting data locks.
* This block is helping an aop path notice the inversion and back
* off to unlock its page lock before trying the dlm lock again.
*/
if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
wait = 0;
if (lockres_remove_mask_waiter(lockres, &mw))
ret = -EAGAIN;
else
goto again;
}
if (wait) {
ret = ocfs2_wait_for_mask(&mw);
if (ret == 0)
goto again;
mlog_errno(ret);
}
mlog_exit(ret);
return ret;
}
static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int level)
{
unsigned long flags;
mlog_entry_void();
spin_lock_irqsave(&lockres->l_lock, flags);
ocfs2_dec_holders(lockres, level);
ocfs2_vote_on_unlock(osb, lockres);
spin_unlock_irqrestore(&lockres->l_lock, flags);
mlog_exit_void();
}
static int ocfs2_create_new_inode_lock(struct inode *inode,
struct ocfs2_lock_res *lockres)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
unsigned long flags;
spin_lock_irqsave(&lockres->l_lock, flags);
BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
spin_unlock_irqrestore(&lockres->l_lock, flags);
return ocfs2_lock_create(osb, lockres, LKM_EXMODE, LKM_LOCAL);
}
/* Grants us an EX lock on the data and metadata resources, skipping
* the normal cluster directory lookup. Use this ONLY on newly created
* inodes which other nodes can't possibly see, and which haven't been
* hashed in the inode hash yet. This can give us a good performance
* increase as it'll skip the network broadcast normally associated
* with creating a new lock resource. */
int ocfs2_create_new_inode_locks(struct inode *inode)
{
int ret;
BUG_ON(!inode);
BUG_ON(!ocfs2_inode_is_new(inode));
mlog_entry_void();
mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno);
/* NOTE: That we don't increment any of the holder counts, nor
* do we add anything to a journal handle. Since this is
* supposed to be a new inode which the cluster doesn't know
* about yet, there is no need to. As far as the LVB handling
* is concerned, this is basically like acquiring an EX lock
* on a resource which has an invalid one -- we'll set it
* valid when we release the EX. */
ret = ocfs2_create_new_inode_lock(inode,
&OCFS2_I(inode)->ip_rw_lockres);
if (ret) {
mlog_errno(ret);
goto bail;
}
ret = ocfs2_create_new_inode_lock(inode,
&OCFS2_I(inode)->ip_meta_lockres);
if (ret) {
mlog_errno(ret);
goto bail;
}
ret = ocfs2_create_new_inode_lock(inode,
&OCFS2_I(inode)->ip_data_lockres);
if (ret) {
mlog_errno(ret);
goto bail;
}
bail:
mlog_exit(ret);
return ret;
}
int ocfs2_rw_lock(struct inode *inode, int write)
{
int status, level;
struct ocfs2_lock_res *lockres;
BUG_ON(!inode);
mlog_entry_void();
mlog(0, "inode %llu take %s RW lock\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
write ? "EXMODE" : "PRMODE");
lockres = &OCFS2_I(inode)->ip_rw_lockres;
level = write ? LKM_EXMODE : LKM_PRMODE;
status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0,
0);
if (status < 0)
mlog_errno(status);
mlog_exit(status);
return status;
}
void ocfs2_rw_unlock(struct inode *inode, int write)
{
int level = write ? LKM_EXMODE : LKM_PRMODE;
struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
mlog_entry_void();
mlog(0, "inode %llu drop %s RW lock\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
write ? "EXMODE" : "PRMODE");
ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
mlog_exit_void();
}
int ocfs2_data_lock_full(struct inode *inode,
int write,
int arg_flags)
{
int status = 0, level;
struct ocfs2_lock_res *lockres;
BUG_ON(!inode);
mlog_entry_void();
mlog(0, "inode %llu take %s DATA lock\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
write ? "EXMODE" : "PRMODE");
/* We'll allow faking a readonly data lock for
* rodevices. */
if (ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) {
if (write) {
status = -EROFS;
mlog_errno(status);
}
goto out;
}
lockres = &OCFS2_I(inode)->ip_data_lockres;
level = write ? LKM_EXMODE : LKM_PRMODE;
status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level,
0, arg_flags);
if (status < 0 && status != -EAGAIN)
mlog_errno(status);
out:
mlog_exit(status);
return status;
}
/* see ocfs2_meta_lock_with_page() */
int ocfs2_data_lock_with_page(struct inode *inode,
int write,
struct page *page)
{
int ret;
ret = ocfs2_data_lock_full(inode, write, OCFS2_LOCK_NONBLOCK);
if (ret == -EAGAIN) {
unlock_page(page);
if (ocfs2_data_lock(inode, write) == 0)
ocfs2_data_unlock(inode, write);
ret = AOP_TRUNCATED_PAGE;
}
return ret;
}
static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres)
{
int kick = 0;
mlog_entry_void();
/* If we know that another node is waiting on our lock, kick
* the vote thread * pre-emptively when we reach a release
* condition. */
if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
switch(lockres->l_blocking) {
case LKM_EXMODE:
if (!lockres->l_ex_holders && !lockres->l_ro_holders)
kick = 1;
break;
case LKM_PRMODE:
if (!lockres->l_ex_holders)
kick = 1;
break;
default:
BUG();
}
}
if (kick)
ocfs2_kick_vote_thread(osb);
mlog_exit_void();
}
void ocfs2_data_unlock(struct inode *inode,
int write)
{
int level = write ? LKM_EXMODE : LKM_PRMODE;
struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_data_lockres;
mlog_entry_void();
mlog(0, "inode %llu drop %s DATA lock\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
write ? "EXMODE" : "PRMODE");
if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)))
ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
mlog_exit_void();
}
#define OCFS2_SEC_BITS 34
#define OCFS2_SEC_SHIFT (64 - 34)
#define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1)
/* LVB only has room for 64 bits of time here so we pack it for
* now. */
static u64 ocfs2_pack_timespec(struct timespec *spec)
{
u64 res;
u64 sec = spec->tv_sec;
u32 nsec = spec->tv_nsec;
res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
return res;
}
/* Call this with the lockres locked. I am reasonably sure we don't
* need ip_lock in this function as anyone who would be changing those
* values is supposed to be blocked in ocfs2_meta_lock right now. */
static void __ocfs2_stuff_meta_lvb(struct inode *inode)
{
struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
struct ocfs2_meta_lvb *lvb;
mlog_entry_void();
lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
lvb->lvb_version = cpu_to_be32(OCFS2_LVB_VERSION);
lvb->lvb_isize = cpu_to_be64(i_size_read(inode));
lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
lvb->lvb_iuid = cpu_to_be32(inode->i_uid);
lvb->lvb_igid = cpu_to_be32(inode->i_gid);
lvb->lvb_imode = cpu_to_be16(inode->i_mode);
lvb->lvb_inlink = cpu_to_be16(inode->i_nlink);
lvb->lvb_iatime_packed =
cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
lvb->lvb_ictime_packed =
cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
lvb->lvb_imtime_packed =
cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
mlog_meta_lvb(0, lockres);
mlog_exit_void();
}
static void ocfs2_unpack_timespec(struct timespec *spec,
u64 packed_time)
{
spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
}
static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
{
struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
struct ocfs2_meta_lvb *lvb;
mlog_entry_void();
mlog_meta_lvb(0, lockres);
lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
/* We're safe here without the lockres lock... */
spin_lock(&oi->ip_lock);
oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
/* fast-symlinks are a special case */
if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
inode->i_blocks = 0;
else
inode->i_blocks =
ocfs2_align_bytes_to_sectors(i_size_read(inode));
inode->i_uid = be32_to_cpu(lvb->lvb_iuid);
inode->i_gid = be32_to_cpu(lvb->lvb_igid);
inode->i_mode = be16_to_cpu(lvb->lvb_imode);
inode->i_nlink = be16_to_cpu(lvb->lvb_inlink);
ocfs2_unpack_timespec(&inode->i_atime,
be64_to_cpu(lvb->lvb_iatime_packed));
ocfs2_unpack_timespec(&inode->i_mtime,
be64_to_cpu(lvb->lvb_imtime_packed));
ocfs2_unpack_timespec(&inode->i_ctime,
be64_to_cpu(lvb->lvb_ictime_packed));
spin_unlock(&oi->ip_lock);
mlog_exit_void();
}
static inline int ocfs2_meta_lvb_is_trustable(struct ocfs2_lock_res *lockres)
{
struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
if (be32_to_cpu(lvb->lvb_version) == OCFS2_LVB_VERSION)
return 1;
return 0;
}
/* Determine whether a lock resource needs to be refreshed, and
* arbitrate who gets to refresh it.
*
* 0 means no refresh needed.
*
* > 0 means you need to refresh this and you MUST call
* ocfs2_complete_lock_res_refresh afterwards. */
static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
{
unsigned long flags;
int status = 0;
mlog_entry_void();
refresh_check:
spin_lock_irqsave(&lockres->l_lock, flags);
if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
spin_unlock_irqrestore(&lockres->l_lock, flags);
goto bail;
}
if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
spin_unlock_irqrestore(&lockres->l_lock, flags);
ocfs2_wait_on_refreshing_lock(lockres);
goto refresh_check;
}
/* Ok, I'll be the one to refresh this lock. */
lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
spin_unlock_irqrestore(&lockres->l_lock, flags);
status = 1;
bail:
mlog_exit(status);
return status;
}
/* If status is non zero, I'll mark it as not being in refresh
* anymroe, but i won't clear the needs refresh flag. */
static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
int status)
{
unsigned long flags;
mlog_entry_void();
spin_lock_irqsave(&lockres->l_lock, flags);
lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
if (!status)
lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
spin_unlock_irqrestore(&lockres->l_lock, flags);
wake_up(&lockres->l_event);
mlog_exit_void();
}
/* may or may not return a bh if it went to disk. */
static int ocfs2_meta_lock_update(struct inode *inode,
struct buffer_head **bh)
{
int status = 0;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_lock_res *lockres;
struct ocfs2_dinode *fe;
mlog_entry_void();
spin_lock(&oi->ip_lock);
if (oi->ip_flags & OCFS2_INODE_DELETED) {
mlog(0, "Orphaned inode %llu was deleted while we "
"were waiting on a lock. ip_flags = 0x%x\n",
(unsigned long long)oi->ip_blkno, oi->ip_flags);
spin_unlock(&oi->ip_lock);
status = -ENOENT;
goto bail;
}
spin_unlock(&oi->ip_lock);
lockres = &oi->ip_meta_lockres;
if (!ocfs2_should_refresh_lock_res(lockres))
goto bail;
/* This will discard any caching information we might have had
* for the inode metadata. */
ocfs2_metadata_cache_purge(inode);
/* will do nothing for inode types that don't use the extent
* map (directories, bitmap files, etc) */
ocfs2_extent_map_trunc(inode, 0);
if (ocfs2_meta_lvb_is_trustable(lockres)) {
mlog(0, "Trusting LVB on inode %llu\n",
(unsigned long long)oi->ip_blkno);
ocfs2_refresh_inode_from_lvb(inode);
} else {
/* Boo, we have to go to disk. */
/* read bh, cast, ocfs2_refresh_inode */
status = ocfs2_read_block(OCFS2_SB(inode->i_sb), oi->ip_blkno,
bh, OCFS2_BH_CACHED, inode);
if (status < 0) {
mlog_errno(status);
goto bail_refresh;
}
fe = (struct ocfs2_dinode *) (*bh)->b_data;
/* This is a good chance to make sure we're not
* locking an invalid object.
*
* We bug on a stale inode here because we checked
* above whether it was wiped from disk. The wiping
* node provides a guarantee that we receive that
* message and can mark the inode before dropping any
* locks associated with it. */
if (!OCFS2_IS_VALID_DINODE(fe)) {
OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
status = -EIO;
goto bail_refresh;
}
mlog_bug_on_msg(inode->i_generation !=
le32_to_cpu(fe->i_generation),
"Invalid dinode %llu disk generation: %u "
"inode->i_generation: %u\n",
(unsigned long long)oi->ip_blkno,
le32_to_cpu(fe->i_generation),
inode->i_generation);
mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
!(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
"Stale dinode %llu dtime: %llu flags: 0x%x\n",
(unsigned long long)oi->ip_blkno,
(unsigned long long)le64_to_cpu(fe->i_dtime),
le32_to_cpu(fe->i_flags));
ocfs2_refresh_inode(inode, fe);
}
status = 0;
bail_refresh:
ocfs2_complete_lock_res_refresh(lockres, status);
bail:
mlog_exit(status);
return status;
}
static int ocfs2_assign_bh(struct inode *inode,
struct buffer_head **ret_bh,
struct buffer_head *passed_bh)
{
int status;
if (passed_bh) {
/* Ok, the update went to disk for us, use the
* returned bh. */
*ret_bh = passed_bh;
get_bh(*ret_bh);
return 0;
}
status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
OCFS2_I(inode)->ip_blkno,
ret_bh,
OCFS2_BH_CACHED,
inode);
if (status < 0)
mlog_errno(status);
return status;
}
/*
* returns < 0 error if the callback will never be called, otherwise
* the result of the lock will be communicated via the callback.
*/
int ocfs2_meta_lock_full(struct inode *inode,
struct ocfs2_journal_handle *handle,
struct buffer_head **ret_bh,
int ex,
int arg_flags)
{
int status, level, dlm_flags, acquired;
struct ocfs2_lock_res *lockres;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct buffer_head *local_bh = NULL;
BUG_ON(!inode);
mlog_entry_void();
mlog(0, "inode %llu, take %s META lock\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
ex ? "EXMODE" : "PRMODE");
status = 0;
acquired = 0;
/* We'll allow faking a readonly metadata lock for
* rodevices. */
if (ocfs2_is_hard_readonly(osb)) {
if (ex)
status = -EROFS;
goto bail;
}
if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
wait_event(osb->recovery_event,
ocfs2_node_map_is_empty(osb, &osb->recovery_map));
acquired = 0;
lockres = &OCFS2_I(inode)->ip_meta_lockres;
level = ex ? LKM_EXMODE : LKM_PRMODE;
dlm_flags = 0;
if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
dlm_flags |= LKM_NOQUEUE;
status = ocfs2_cluster_lock(osb, lockres, level, dlm_flags, arg_flags);
if (status < 0) {
if (status != -EAGAIN && status != -EIOCBRETRY)
mlog_errno(status);
goto bail;
}
/* Notify the error cleanup path to drop the cluster lock. */
acquired = 1;
/* We wait twice because a node may have died while we were in
* the lower dlm layers. The second time though, we've
* committed to owning this lock so we don't allow signals to
* abort the operation. */
if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
wait_event(osb->recovery_event,
ocfs2_node_map_is_empty(osb, &osb->recovery_map));
/* This is fun. The caller may want a bh back, or it may
* not. ocfs2_meta_lock_update definitely wants one in, but
* may or may not read one, depending on what's in the
* LVB. The result of all of this is that we've *only* gone to
* disk if we have to, so the complexity is worthwhile. */
status = ocfs2_meta_lock_update(inode, &local_bh);
if (status < 0) {
if (status != -ENOENT)
mlog_errno(status);
goto bail;
}
if (ret_bh) {
status = ocfs2_assign_bh(inode, ret_bh, local_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
}
if (handle) {
status = ocfs2_handle_add_lock(handle, inode);
if (status < 0)
mlog_errno(status);
}
bail:
if (status < 0) {
if (ret_bh && (*ret_bh)) {
brelse(*ret_bh);
*ret_bh = NULL;
}
if (acquired)
ocfs2_meta_unlock(inode, ex);
}
if (local_bh)
brelse(local_bh);
mlog_exit(status);
return status;
}
/*
* This is working around a lock inversion between tasks acquiring DLM locks
* while holding a page lock and the vote thread which blocks dlm lock acquiry
* while acquiring page locks.
*
* ** These _with_page variantes are only intended to be called from aop
* methods that hold page locks and return a very specific *positive* error
* code that aop methods pass up to the VFS -- test for errors with != 0. **
*
* The DLM is called such that it returns -EAGAIN if it would have blocked
* waiting for the vote thread. In that case we unlock our page so the vote
* thread can make progress. Once we've done this we have to return
* AOP_TRUNCATED_PAGE so the aop method that called us can bubble that back up
* into the VFS who will then immediately retry the aop call.
*
* We do a blocking lock and immediate unlock before returning, though, so that
* the lock has a great chance of being cached on this node by the time the VFS
* calls back to retry the aop. This has a potential to livelock as nodes
* ping locks back and forth, but that's a risk we're willing to take to avoid
* the lock inversion simply.
*/
int ocfs2_meta_lock_with_page(struct inode *inode,
struct ocfs2_journal_handle *handle,
struct buffer_head **ret_bh,
int ex,
struct page *page)
{
int ret;
ret = ocfs2_meta_lock_full(inode, handle, ret_bh, ex,
OCFS2_LOCK_NONBLOCK);
if (ret == -EAGAIN) {
unlock_page(page);
if (ocfs2_meta_lock(inode, handle, ret_bh, ex) == 0)
ocfs2_meta_unlock(inode, ex);
ret = AOP_TRUNCATED_PAGE;
}
return ret;
}
void ocfs2_meta_unlock(struct inode *inode,
int ex)
{
int level = ex ? LKM_EXMODE : LKM_PRMODE;
struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;
mlog_entry_void();
mlog(0, "inode %llu drop %s META lock\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
ex ? "EXMODE" : "PRMODE");
if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)))
ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
mlog_exit_void();
}
int ocfs2_super_lock(struct ocfs2_super *osb,
int ex)
{
int status;
int level = ex ? LKM_EXMODE : LKM_PRMODE;
struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
struct buffer_head *bh;
struct ocfs2_slot_info *si = osb->slot_info;
mlog_entry_void();
if (ocfs2_is_hard_readonly(osb))
return -EROFS;
status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
if (status < 0) {
mlog_errno(status);
goto bail;
}
/* The super block lock path is really in the best position to
* know when resources covered by the lock need to be
* refreshed, so we do it here. Of course, making sense of
* everything is up to the caller :) */
status = ocfs2_should_refresh_lock_res(lockres);
if (status < 0) {
mlog_errno(status);
goto bail;
}
if (status) {
bh = si->si_bh;
status = ocfs2_read_block(osb, bh->b_blocknr, &bh, 0,
si->si_inode);
if (status == 0)
ocfs2_update_slot_info(si);
ocfs2_complete_lock_res_refresh(lockres, status);
if (status < 0)
mlog_errno(status);
}
bail:
mlog_exit(status);
return status;
}
void ocfs2_super_unlock(struct ocfs2_super *osb,
int ex)
{
int level = ex ? LKM_EXMODE : LKM_PRMODE;
struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
ocfs2_cluster_unlock(osb, lockres, level);
}
int ocfs2_rename_lock(struct ocfs2_super *osb)
{
int status;
struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
if (ocfs2_is_hard_readonly(osb))
return -EROFS;
status = ocfs2_cluster_lock(osb, lockres, LKM_EXMODE, 0, 0);
if (status < 0)
mlog_errno(status);
return status;
}
void ocfs2_rename_unlock(struct ocfs2_super *osb)
{
struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
ocfs2_cluster_unlock(osb, lockres, LKM_EXMODE);
}
/* Reference counting of the dlm debug structure. We want this because
* open references on the debug inodes can live on after a mount, so
* we can't rely on the ocfs2_super to always exist. */
static void ocfs2_dlm_debug_free(struct kref *kref)
{
struct ocfs2_dlm_debug *dlm_debug;
dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
kfree(dlm_debug);
}
void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
{
if (dlm_debug)
kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
}
static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
{
kref_get(&debug->d_refcnt);
}
struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
{
struct ocfs2_dlm_debug *dlm_debug;
dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
if (!dlm_debug) {
mlog_errno(-ENOMEM);
goto out;
}
kref_init(&dlm_debug->d_refcnt);
INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
dlm_debug->d_locking_state = NULL;
out:
return dlm_debug;
}
/* Access to this is arbitrated for us via seq_file->sem. */
struct ocfs2_dlm_seq_priv {
struct ocfs2_dlm_debug *p_dlm_debug;
struct ocfs2_lock_res p_iter_res;
struct ocfs2_lock_res p_tmp_res;
};
static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
struct ocfs2_dlm_seq_priv *priv)
{
struct ocfs2_lock_res *iter, *ret = NULL;
struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
assert_spin_locked(&ocfs2_dlm_tracking_lock);
list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
/* discover the head of the list */
if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
mlog(0, "End of list found, %p\n", ret);
break;
}
/* We track our "dummy" iteration lockres' by a NULL
* l_ops field. */
if (iter->l_ops != NULL) {
ret = iter;
break;
}
}
return ret;
}
static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
{
struct ocfs2_dlm_seq_priv *priv = m->private;
struct ocfs2_lock_res *iter;
spin_lock(&ocfs2_dlm_tracking_lock);
iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
if (iter) {
/* Since lockres' have the lifetime of their container
* (which can be inodes, ocfs2_supers, etc) we want to
* copy this out to a temporary lockres while still
* under the spinlock. Obviously after this we can't
* trust any pointers on the copy returned, but that's
* ok as the information we want isn't typically held
* in them. */
priv->p_tmp_res = *iter;
iter = &priv->p_tmp_res;
}
spin_unlock(&ocfs2_dlm_tracking_lock);
return iter;
}
static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
{
}
static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
struct ocfs2_dlm_seq_priv *priv = m->private;
struct ocfs2_lock_res *iter = v;
struct ocfs2_lock_res *dummy = &priv->p_iter_res;
spin_lock(&ocfs2_dlm_tracking_lock);
iter = ocfs2_dlm_next_res(iter, priv);
list_del_init(&dummy->l_debug_list);
if (iter) {
list_add(&dummy->l_debug_list, &iter->l_debug_list);
priv->p_tmp_res = *iter;
iter = &priv->p_tmp_res;
}
spin_unlock(&ocfs2_dlm_tracking_lock);
return iter;
}
/* So that debugfs.ocfs2 can determine which format is being used */
#define OCFS2_DLM_DEBUG_STR_VERSION 1
static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
{
int i;
char *lvb;
struct ocfs2_lock_res *lockres = v;
if (!lockres)
return -EINVAL;
seq_printf(m, "0x%x\t"
"%.*s\t"
"%d\t"
"0x%lx\t"
"0x%x\t"
"0x%x\t"
"%u\t"
"%u\t"
"%d\t"
"%d\t",
OCFS2_DLM_DEBUG_STR_VERSION,
OCFS2_LOCK_ID_MAX_LEN, lockres->l_name,
lockres->l_level,
lockres->l_flags,
lockres->l_action,
lockres->l_unlock_action,
lockres->l_ro_holders,
lockres->l_ex_holders,
lockres->l_requested,
lockres->l_blocking);
/* Dump the raw LVB */
lvb = lockres->l_lksb.lvb;
for(i = 0; i < DLM_LVB_LEN; i++)
seq_printf(m, "0x%x\t", lvb[i]);
/* End the line */
seq_printf(m, "\n");
return 0;
}
static struct seq_operations ocfs2_dlm_seq_ops = {
.start = ocfs2_dlm_seq_start,
.stop = ocfs2_dlm_seq_stop,
.next = ocfs2_dlm_seq_next,
.show = ocfs2_dlm_seq_show,
};
static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
{
struct seq_file *seq = (struct seq_file *) file->private_data;
struct ocfs2_dlm_seq_priv *priv = seq->private;
struct ocfs2_lock_res *res = &priv->p_iter_res;
ocfs2_remove_lockres_tracking(res);
ocfs2_put_dlm_debug(priv->p_dlm_debug);
return seq_release_private(inode, file);
}
static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
{
int ret;
struct ocfs2_dlm_seq_priv *priv;
struct seq_file *seq;
struct ocfs2_super *osb;
priv = kzalloc(sizeof(struct ocfs2_dlm_seq_priv), GFP_KERNEL);
if (!priv) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
osb = (struct ocfs2_super *) inode->u.generic_ip;
ocfs2_get_dlm_debug(osb->osb_dlm_debug);
priv->p_dlm_debug = osb->osb_dlm_debug;
INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
ret = seq_open(file, &ocfs2_dlm_seq_ops);
if (ret) {
kfree(priv);
mlog_errno(ret);
goto out;
}
seq = (struct seq_file *) file->private_data;
seq->private = priv;
ocfs2_add_lockres_tracking(&priv->p_iter_res,
priv->p_dlm_debug);
out:
return ret;
}
static const struct file_operations ocfs2_dlm_debug_fops = {
.open = ocfs2_dlm_debug_open,
.release = ocfs2_dlm_debug_release,
.read = seq_read,
.llseek = seq_lseek,
};
static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
{
int ret = 0;
struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
dlm_debug->d_locking_state = debugfs_create_file("locking_state",
S_IFREG|S_IRUSR,
osb->osb_debug_root,
osb,
&ocfs2_dlm_debug_fops);
if (!dlm_debug->d_locking_state) {
ret = -EINVAL;
mlog(ML_ERROR,
"Unable to create locking state debugfs file.\n");
goto out;
}
ocfs2_get_dlm_debug(dlm_debug);
out:
return ret;
}
static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
{
struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
if (dlm_debug) {
debugfs_remove(dlm_debug->d_locking_state);
ocfs2_put_dlm_debug(dlm_debug);
}
}
int ocfs2_dlm_init(struct ocfs2_super *osb)
{
int status;
u32 dlm_key;
struct dlm_ctxt *dlm;
mlog_entry_void();
status = ocfs2_dlm_init_debug(osb);
if (status < 0) {
mlog_errno(status);
goto bail;
}
/* launch vote thread */
osb->vote_task = kthread_run(ocfs2_vote_thread, osb, "ocfs2vote-%d",
osb->osb_id);
if (IS_ERR(osb->vote_task)) {
status = PTR_ERR(osb->vote_task);
osb->vote_task = NULL;
mlog_errno(status);
goto bail;
}
/* used by the dlm code to make message headers unique, each
* node in this domain must agree on this. */
dlm_key = crc32_le(0, osb->uuid_str, strlen(osb->uuid_str));
/* for now, uuid == domain */
dlm = dlm_register_domain(osb->uuid_str, dlm_key);
if (IS_ERR(dlm)) {
status = PTR_ERR(dlm);
mlog_errno(status);
goto bail;
}
ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
dlm_register_eviction_cb(dlm, &osb->osb_eviction_cb);
osb->dlm = dlm;
status = 0;
bail:
if (status < 0) {
ocfs2_dlm_shutdown_debug(osb);
if (osb->vote_task)
kthread_stop(osb->vote_task);
}
mlog_exit(status);
return status;
}
void ocfs2_dlm_shutdown(struct ocfs2_super *osb)
{
mlog_entry_void();
dlm_unregister_eviction_cb(&osb->osb_eviction_cb);
ocfs2_drop_osb_locks(osb);
if (osb->vote_task) {
kthread_stop(osb->vote_task);
osb->vote_task = NULL;
}
ocfs2_lock_res_free(&osb->osb_super_lockres);
ocfs2_lock_res_free(&osb->osb_rename_lockres);
dlm_unregister_domain(osb->dlm);
osb->dlm = NULL;
ocfs2_dlm_shutdown_debug(osb);
mlog_exit_void();
}
static void ocfs2_unlock_ast_func(void *opaque, enum dlm_status status)
{
struct ocfs2_lock_res *lockres = opaque;
unsigned long flags;
mlog_entry_void();
mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name,
lockres->l_unlock_action);
spin_lock_irqsave(&lockres->l_lock, flags);
/* We tried to cancel a convert request, but it was already
* granted. All we want to do here is clear our unlock
* state. The wake_up call done at the bottom is redundant
* (ocfs2_prepare_cancel_convert doesn't sleep on this) but doesn't
* hurt anything anyway */
if (status == DLM_CANCELGRANT &&
lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
mlog(0, "Got cancelgrant for %s\n", lockres->l_name);
/* We don't clear the busy flag in this case as it
* should have been cleared by the ast which the dlm
* has called. */
goto complete_unlock;
}
if (status != DLM_NORMAL) {
mlog(ML_ERROR, "Dlm passes status %d for lock %s, "
"unlock_action %d\n", status, lockres->l_name,
lockres->l_unlock_action);
spin_unlock_irqrestore(&lockres->l_lock, flags);
return;
}
switch(lockres->l_unlock_action) {
case OCFS2_UNLOCK_CANCEL_CONVERT:
mlog(0, "Cancel convert success for %s\n", lockres->l_name);
lockres->l_action = OCFS2_AST_INVALID;
break;
case OCFS2_UNLOCK_DROP_LOCK:
lockres->l_level = LKM_IVMODE;
break;
default:
BUG();
}
lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
complete_unlock:
lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
spin_unlock_irqrestore(&lockres->l_lock, flags);
wake_up(&lockres->l_event);
mlog_exit_void();
}
typedef void (ocfs2_pre_drop_cb_t)(struct ocfs2_lock_res *, void *);
struct drop_lock_cb {
ocfs2_pre_drop_cb_t *drop_func;
void *drop_data;
};
static int ocfs2_drop_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
struct drop_lock_cb *dcb)
{
enum dlm_status status;
unsigned long flags;
/* We didn't get anywhere near actually using this lockres. */
if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
goto out;
spin_lock_irqsave(&lockres->l_lock, flags);
mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
"lockres %s, flags 0x%lx\n",
lockres->l_name, lockres->l_flags);
while (lockres->l_flags & OCFS2_LOCK_BUSY) {
mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
"%u, unlock_action = %u\n",
lockres->l_name, lockres->l_flags, lockres->l_action,
lockres->l_unlock_action);
spin_unlock_irqrestore(&lockres->l_lock, flags);
/* XXX: Today we just wait on any busy
* locks... Perhaps we need to cancel converts in the
* future? */
ocfs2_wait_on_busy_lock(lockres);
spin_lock_irqsave(&lockres->l_lock, flags);
}
if (dcb)
dcb->drop_func(lockres, dcb->drop_data);
if (lockres->l_flags & OCFS2_LOCK_BUSY)
mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
lockres->l_name);
if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);
if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
spin_unlock_irqrestore(&lockres->l_lock, flags);
goto out;
}
lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);
/* make sure we never get here while waiting for an ast to
* fire. */
BUG_ON(lockres->l_action != OCFS2_AST_INVALID);
/* is this necessary? */
lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
spin_unlock_irqrestore(&lockres->l_lock, flags);
mlog(0, "lock %s\n", lockres->l_name);
status = dlmunlock(osb->dlm, &lockres->l_lksb, LKM_VALBLK,
lockres->l_ops->unlock_ast, lockres);
if (status != DLM_NORMAL) {
ocfs2_log_dlm_error("dlmunlock", status, lockres);
mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
dlm_print_one_lock(lockres->l_lksb.lockid);
BUG();
}
mlog(0, "lock %s, successfull return from dlmunlock\n",
lockres->l_name);
ocfs2_wait_on_busy_lock(lockres);
out:
mlog_exit(0);
return 0;
}
/* Mark the lockres as being dropped. It will no longer be
* queued if blocking, but we still may have to wait on it
* being dequeued from the vote thread before we can consider
* it safe to drop.
*
* You can *not* attempt to call cluster_lock on this lockres anymore. */
void ocfs2_mark_lockres_freeing(struct ocfs2_lock_res *lockres)
{
int status;
struct ocfs2_mask_waiter mw;
unsigned long flags;
ocfs2_init_mask_waiter(&mw);
spin_lock_irqsave(&lockres->l_lock, flags);
lockres->l_flags |= OCFS2_LOCK_FREEING;
while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
spin_unlock_irqrestore(&lockres->l_lock, flags);
mlog(0, "Waiting on lockres %s\n", lockres->l_name);
status = ocfs2_wait_for_mask(&mw);
if (status)
mlog_errno(status);
spin_lock_irqsave(&lockres->l_lock, flags);
}
spin_unlock_irqrestore(&lockres->l_lock, flags);
}
static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
{
int status;
mlog_entry_void();
ocfs2_mark_lockres_freeing(&osb->osb_super_lockres);
status = ocfs2_drop_lock(osb, &osb->osb_super_lockres, NULL);
if (status < 0)
mlog_errno(status);
ocfs2_mark_lockres_freeing(&osb->osb_rename_lockres);
status = ocfs2_drop_lock(osb, &osb->osb_rename_lockres, NULL);
if (status < 0)
mlog_errno(status);
mlog_exit(status);
}
static void ocfs2_meta_pre_drop(struct ocfs2_lock_res *lockres, void *data)
{
struct inode *inode = data;
/* the metadata lock requires a bit more work as we have an
* LVB to worry about. */
if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
lockres->l_level == LKM_EXMODE &&
!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
__ocfs2_stuff_meta_lvb(inode);
}
int ocfs2_drop_inode_locks(struct inode *inode)
{
int status, err;
struct drop_lock_cb meta_dcb = { ocfs2_meta_pre_drop, inode, };
mlog_entry_void();
/* No need to call ocfs2_mark_lockres_freeing here -
* ocfs2_clear_inode has done it for us. */
err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
&OCFS2_I(inode)->ip_data_lockres,
NULL);
if (err < 0)
mlog_errno(err);
status = err;
err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
&OCFS2_I(inode)->ip_meta_lockres,
&meta_dcb);
if (err < 0)
mlog_errno(err);
if (err < 0 && !status)
status = err;
err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
&OCFS2_I(inode)->ip_rw_lockres,
NULL);
if (err < 0)
mlog_errno(err);
if (err < 0 && !status)
status = err;
mlog_exit(status);
return status;
}
static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
int new_level)
{
assert_spin_locked(&lockres->l_lock);
BUG_ON(lockres->l_blocking <= LKM_NLMODE);
if (lockres->l_level <= new_level) {
mlog(ML_ERROR, "lockres->l_level (%u) <= new_level (%u)\n",
lockres->l_level, new_level);
BUG();
}
mlog(0, "lock %s, new_level = %d, l_blocking = %d\n",
lockres->l_name, new_level, lockres->l_blocking);
lockres->l_action = OCFS2_AST_DOWNCONVERT;
lockres->l_requested = new_level;
lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
}
static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int new_level,
int lvb)
{
int ret, dlm_flags = LKM_CONVERT;
enum dlm_status status;
mlog_entry_void();
if (lvb)
dlm_flags |= LKM_VALBLK;
status = dlmlock(osb->dlm,
new_level,
&lockres->l_lksb,
dlm_flags,
lockres->l_name,
lockres->l_ops->ast,
lockres,
lockres->l_ops->bast);
if (status != DLM_NORMAL) {
ocfs2_log_dlm_error("dlmlock", status, lockres);
ret = -EINVAL;
ocfs2_recover_from_dlm_error(lockres, 1);
goto bail;
}
ret = 0;
bail:
mlog_exit(ret);
return ret;
}
/* returns 1 when the caller should unlock and call dlmunlock */
static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres)
{
assert_spin_locked(&lockres->l_lock);
mlog_entry_void();
mlog(0, "lock %s\n", lockres->l_name);
if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
/* If we're already trying to cancel a lock conversion
* then just drop the spinlock and allow the caller to
* requeue this lock. */
mlog(0, "Lockres %s, skip convert\n", lockres->l_name);
return 0;
}
/* were we in a convert when we got the bast fire? */
BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
lockres->l_action != OCFS2_AST_DOWNCONVERT);
/* set things up for the unlockast to know to just
* clear out the ast_action and unset busy, etc. */
lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;
mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
"lock %s, invalid flags: 0x%lx\n",
lockres->l_name, lockres->l_flags);
return 1;
}
static int ocfs2_cancel_convert(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres)
{
int ret;
enum dlm_status status;
mlog_entry_void();
mlog(0, "lock %s\n", lockres->l_name);
ret = 0;
status = dlmunlock(osb->dlm,
&lockres->l_lksb,
LKM_CANCEL,
lockres->l_ops->unlock_ast,
lockres);
if (status != DLM_NORMAL) {
ocfs2_log_dlm_error("dlmunlock", status, lockres);
ret = -EINVAL;
ocfs2_recover_from_dlm_error(lockres, 0);
}
mlog(0, "lock %s return from dlmunlock\n", lockres->l_name);
mlog_exit(ret);
return ret;
}
static inline int ocfs2_can_downconvert_meta_lock(struct inode *inode,
struct ocfs2_lock_res *lockres,
int new_level)
{
int ret;
mlog_entry_void();
BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE);
if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
ret = 0;
mlog(0, "lockres %s currently being refreshed -- backing "
"off!\n", lockres->l_name);
} else if (new_level == LKM_PRMODE)
ret = !lockres->l_ex_holders &&
ocfs2_inode_fully_checkpointed(inode);
else /* Must be NLMODE we're converting to. */
ret = !lockres->l_ro_holders && !lockres->l_ex_holders &&
ocfs2_inode_fully_checkpointed(inode);
mlog_exit(ret);
return ret;
}
static int ocfs2_do_unblock_meta(struct inode *inode,
int *requeue)
{
int new_level;
int set_lvb = 0;
int ret = 0;
struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;
unsigned long flags;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
mlog_entry_void();
spin_lock_irqsave(&lockres->l_lock, flags);
BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
mlog(0, "l_level=%d, l_blocking=%d\n", lockres->l_level,
lockres->l_blocking);
BUG_ON(lockres->l_level != LKM_EXMODE &&
lockres->l_level != LKM_PRMODE);
if (lockres->l_flags & OCFS2_LOCK_BUSY) {
*requeue = 1;
ret = ocfs2_prepare_cancel_convert(osb, lockres);
spin_unlock_irqrestore(&lockres->l_lock, flags);
if (ret) {
ret = ocfs2_cancel_convert(osb, lockres);
if (ret < 0)
mlog_errno(ret);
}
goto leave;
}
new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
mlog(0, "l_level=%d, l_blocking=%d, new_level=%d\n",
lockres->l_level, lockres->l_blocking, new_level);
if (ocfs2_can_downconvert_meta_lock(inode, lockres, new_level)) {
if (lockres->l_level == LKM_EXMODE)
set_lvb = 1;
/* If the lock hasn't been refreshed yet (rare), then
* our memory inode values are old and we skip
* stuffing the lvb. There's no need to actually clear
* out the lvb here as it's value is still valid. */
if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
if (set_lvb)
__ocfs2_stuff_meta_lvb(inode);
} else
mlog(0, "lockres %s: downconverting stale lock!\n",
lockres->l_name);
mlog(0, "calling ocfs2_downconvert_lock with l_level=%d, "
"l_blocking=%d, new_level=%d\n",
lockres->l_level, lockres->l_blocking, new_level);
ocfs2_prepare_downconvert(lockres, new_level);
spin_unlock_irqrestore(&lockres->l_lock, flags);
ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb);
goto leave;
}
if (!ocfs2_inode_fully_checkpointed(inode))
ocfs2_start_checkpoint(osb);
*requeue = 1;
spin_unlock_irqrestore(&lockres->l_lock, flags);
ret = 0;
leave:
mlog_exit(ret);
return ret;
}
static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int *requeue,
ocfs2_convert_worker_t *worker)
{
unsigned long flags;
int blocking;
int new_level;
int ret = 0;
mlog_entry_void();
spin_lock_irqsave(&lockres->l_lock, flags);
BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
recheck:
if (lockres->l_flags & OCFS2_LOCK_BUSY) {
*requeue = 1;
ret = ocfs2_prepare_cancel_convert(osb, lockres);
spin_unlock_irqrestore(&lockres->l_lock, flags);
if (ret) {
ret = ocfs2_cancel_convert(osb, lockres);
if (ret < 0)
mlog_errno(ret);
}
goto leave;
}
/* if we're blocking an exclusive and we have *any* holders,
* then requeue. */
if ((lockres->l_blocking == LKM_EXMODE)
&& (lockres->l_ex_holders || lockres->l_ro_holders)) {
spin_unlock_irqrestore(&lockres->l_lock, flags);
*requeue = 1;
ret = 0;
goto leave;
}
/* If it's a PR we're blocking, then only
* requeue if we've got any EX holders */
if (lockres->l_blocking == LKM_PRMODE &&
lockres->l_ex_holders) {
spin_unlock_irqrestore(&lockres->l_lock, flags);
*requeue = 1;
ret = 0;
goto leave;
}
/* If we get here, then we know that there are no more
* incompatible holders (and anyone asking for an incompatible
* lock is blocked). We can now downconvert the lock */
if (!worker)
goto downconvert;
/* Some lockres types want to do a bit of work before
* downconverting a lock. Allow that here. The worker function
* may sleep, so we save off a copy of what we're blocking as
* it may change while we're not holding the spin lock. */
blocking = lockres->l_blocking;
spin_unlock_irqrestore(&lockres->l_lock, flags);
worker(lockres, blocking);
spin_lock_irqsave(&lockres->l_lock, flags);
if (blocking != lockres->l_blocking) {
/* If this changed underneath us, then we can't drop
* it just yet. */
goto recheck;
}
downconvert:
*requeue = 0;
new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
ocfs2_prepare_downconvert(lockres, new_level);
spin_unlock_irqrestore(&lockres->l_lock, flags);
ret = ocfs2_downconvert_lock(osb, lockres, new_level, 0);
leave:
mlog_exit(ret);
return ret;
}
static void ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
int blocking)
{
struct inode *inode;
struct address_space *mapping;
mlog_entry_void();
inode = ocfs2_lock_res_inode(lockres);
mapping = inode->i_mapping;
if (filemap_fdatawrite(mapping)) {
mlog(ML_ERROR, "Could not sync inode %llu for downconvert!",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
}
sync_mapping_buffers(mapping);
if (blocking == LKM_EXMODE) {
truncate_inode_pages(mapping, 0);
unmap_mapping_range(mapping, 0, 0, 0);
} else {
/* We only need to wait on the I/O if we're not also
* truncating pages because truncate_inode_pages waits
* for us above. We don't truncate pages if we're
* blocking anything < EXMODE because we want to keep
* them around in that case. */
filemap_fdatawait(mapping);
}
mlog_exit_void();
}
int ocfs2_unblock_data(struct ocfs2_lock_res *lockres,
int *requeue)
{
int status;
struct inode *inode;
struct ocfs2_super *osb;
mlog_entry_void();
inode = ocfs2_lock_res_inode(lockres);
osb = OCFS2_SB(inode->i_sb);
mlog(0, "unblock inode %llu\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
status = ocfs2_generic_unblock_lock(osb,
lockres,
requeue,
ocfs2_data_convert_worker);
if (status < 0)
mlog_errno(status);
mlog(0, "inode %llu, requeue = %d\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno, *requeue);
mlog_exit(status);
return status;
}
static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres,
int *requeue)
{
int status;
struct inode *inode;
mlog_entry_void();
mlog(0, "Unblock lockres %s\n", lockres->l_name);
inode = ocfs2_lock_res_inode(lockres);
status = ocfs2_generic_unblock_lock(OCFS2_SB(inode->i_sb),
lockres,
requeue,
NULL);
if (status < 0)
mlog_errno(status);
mlog_exit(status);
return status;
}
int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres,
int *requeue)
{
int status;
struct inode *inode;
mlog_entry_void();
inode = ocfs2_lock_res_inode(lockres);
mlog(0, "unblock inode %llu\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
status = ocfs2_do_unblock_meta(inode, requeue);
if (status < 0)
mlog_errno(status);
mlog(0, "inode %llu, requeue = %d\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno, *requeue);
mlog_exit(status);
return status;
}
/* Generic unblock function for any lockres whose private data is an
* ocfs2_super pointer. */
static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres,
int *requeue)
{
int status;
struct ocfs2_super *osb;
mlog_entry_void();
mlog(0, "Unblock lockres %s\n", lockres->l_name);
osb = ocfs2_lock_res_super(lockres);
status = ocfs2_generic_unblock_lock(osb,
lockres,
requeue,
NULL);
if (status < 0)
mlog_errno(status);
mlog_exit(status);
return status;
}
void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres)
{
int status;
int requeue = 0;
unsigned long flags;
/* Our reference to the lockres in this function can be
* considered valid until we remove the OCFS2_LOCK_QUEUED
* flag. */
mlog_entry_void();
BUG_ON(!lockres);
BUG_ON(!lockres->l_ops);
BUG_ON(!lockres->l_ops->unblock);
mlog(0, "lockres %s blocked.\n", lockres->l_name);
/* Detect whether a lock has been marked as going away while
* the vote thread was processing other things. A lock can
* still be marked with OCFS2_LOCK_FREEING after this check,
* but short circuiting here will still save us some
* performance. */
spin_lock_irqsave(&lockres->l_lock, flags);
if (lockres->l_flags & OCFS2_LOCK_FREEING)
goto unqueue;
spin_unlock_irqrestore(&lockres->l_lock, flags);
status = lockres->l_ops->unblock(lockres, &requeue);
if (status < 0)
mlog_errno(status);
spin_lock_irqsave(&lockres->l_lock, flags);
unqueue:
if (lockres->l_flags & OCFS2_LOCK_FREEING || !requeue) {
lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
} else
ocfs2_schedule_blocked_lock(osb, lockres);
mlog(0, "lockres %s, requeue = %s.\n", lockres->l_name,
requeue ? "yes" : "no");
spin_unlock_irqrestore(&lockres->l_lock, flags);
mlog_exit_void();
}
static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres)
{
mlog_entry_void();
assert_spin_locked(&lockres->l_lock);
if (lockres->l_flags & OCFS2_LOCK_FREEING) {
/* Do not schedule a lock for downconvert when it's on
* the way to destruction - any nodes wanting access
* to the resource will get it soon. */
mlog(0, "Lockres %s won't be scheduled: flags 0x%lx\n",
lockres->l_name, lockres->l_flags);
return;
}
lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
spin_lock(&osb->vote_task_lock);
if (list_empty(&lockres->l_blocked_list)) {
list_add_tail(&lockres->l_blocked_list,
&osb->blocked_lock_list);
osb->blocked_lock_count++;
}
spin_unlock(&osb->vote_task_lock);
mlog_exit_void();
}
/* This aids in debugging situations where a bad LVB might be involved. */
void ocfs2_dump_meta_lvb_info(u64 level,
const char *function,
unsigned int line,
struct ocfs2_lock_res *lockres)
{
struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
mlog(level, "LVB information for %s (called from %s:%u):\n",
lockres->l_name, function, line);
mlog(level, "version: %u, clusters: %u\n",
be32_to_cpu(lvb->lvb_version), be32_to_cpu(lvb->lvb_iclusters));
mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n",
(unsigned long long)be64_to_cpu(lvb->lvb_isize),
be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid),
be16_to_cpu(lvb->lvb_imode));
mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, "
"mtime_packed 0x%llx\n", be16_to_cpu(lvb->lvb_inlink),
(long long)be64_to_cpu(lvb->lvb_iatime_packed),
(long long)be64_to_cpu(lvb->lvb_ictime_packed),
(long long)be64_to_cpu(lvb->lvb_imtime_packed));
}
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