diff options
Diffstat (limited to 'fs/ocfs2/dlmglue.c')
| -rw-r--r-- | fs/ocfs2/dlmglue.c | 2904 |
1 files changed, 2904 insertions, 0 deletions
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c new file mode 100644 index 000000000000..e971ec2f8407 --- /dev/null +++ b/fs/ocfs2/dlmglue.c @@ -0,0 +1,2904 @@ +/* -*- 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%016"MLFx64"%08x", + ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD, 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 %"MLFu64", l_action = %u, type = %s\n", + 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 %"MLFu64"\n", lksb->status, + 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 %"MLFu64", blocking = %d, level = %d " + "type = %s\n", 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 %"MLFu64"\n", 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 %"MLFu64" take %s RW lock\n", + 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 %"MLFu64" drop %s RW lock\n", + 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 %"MLFu64" take %s DATA lock\n", + 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 %"MLFu64" drop %s DATA lock\n", + 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 %"MLFu64" was deleted while we " + "were waiting on a lock. ip_flags = 0x%x\n", + 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 %"MLFu64"\n", + 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 %"MLFu64" disk generation: %u " + "inode->i_generation: %u\n", + 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 %"MLFu64" dtime: %"MLFu64" " + "flags: 0x%x\n", oi->ip_blkno, + 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 %"MLFu64", take %s META lock\n", + 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 %"MLFu64" drop %s META lock\n", + 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 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 %"MLFu64" for downconvert!", + 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 %"MLFu64"\n", 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 %"MLFu64", requeue = %d\n", + 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 %"MLFu64"\n", OCFS2_I(inode)->ip_blkno); + + status = ocfs2_do_unblock_meta(inode, requeue); + if (status < 0) + mlog_errno(status); + + mlog(0, "inode %"MLFu64", requeue = %d\n", + 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: %"MLFu64", uid %u, gid %u, mode 0x%x\n", + 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%"MLFx64", " + "ctime_packed 0x%"MLFx64", mtime_packed 0x%"MLFx64"\n", + be16_to_cpu(lvb->lvb_inlink), be64_to_cpu(lvb->lvb_iatime_packed), + be64_to_cpu(lvb->lvb_ictime_packed), + be64_to_cpu(lvb->lvb_imtime_packed)); +} |