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, leve |