diff options
Diffstat (limited to 'fs/ocfs2/dlmglue.c')
-rw-r--r-- | fs/ocfs2/dlmglue.c | 475 |
1 files changed, 371 insertions, 104 deletions
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index 20c6ca8ac7f..764d15defd8 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -46,6 +46,7 @@ #include "ocfs2.h" #include "alloc.h" +#include "dcache.h" #include "dlmglue.h" #include "extent_map.h" #include "heartbeat.h" @@ -69,6 +70,9 @@ struct ocfs2_mask_waiter { static void ocfs2_inode_ast_func(void *opaque); static void ocfs2_inode_bast_func(void *opaque, int level); +static void ocfs2_dentry_ast_func(void *opaque); +static void ocfs2_dentry_bast_func(void *opaque, + int level); static void ocfs2_super_ast_func(void *opaque); static void ocfs2_super_bast_func(void *opaque, int level); @@ -76,32 +80,57 @@ static void ocfs2_rename_ast_func(void *opaque); static void ocfs2_rename_bast_func(void *opaque, int level); +/* + * Return value from ocfs2_convert_worker_t functions. + * + * These control the precise actions of ocfs2_generic_unblock_lock() + * and ocfs2_process_blocked_lock() + * + */ +enum ocfs2_unblock_action { + UNBLOCK_CONTINUE = 0, /* Continue downconvert */ + UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire + * ->post_unlock callback */ + UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire + * ->post_unlock() callback. */ +}; + +struct ocfs2_unblock_ctl { + int requeue; + enum ocfs2_unblock_action unblock_action; +}; + /* 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); + struct ocfs2_unblock_ctl *ctl); static int ocfs2_unblock_data(struct ocfs2_lock_res *lockres, - int *requeue); + struct ocfs2_unblock_ctl *ctl); static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres, - int *requeue); + struct ocfs2_unblock_ctl *ctl); +static int ocfs2_unblock_dentry_lock(struct ocfs2_lock_res *lockres, + struct ocfs2_unblock_ctl *ctl); 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_unblock_ctl *ctl); + +static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, + struct ocfs2_lock_res *lockres); 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 *); + int (*unblock)(struct ocfs2_lock_res *, struct ocfs2_unblock_ctl *); + void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *); }; +typedef int (ocfs2_convert_worker_t)(struct ocfs2_lock_res *, int); +static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb, + struct ocfs2_lock_res *lockres, + struct ocfs2_unblock_ctl *ctl, + ocfs2_convert_worker_t *worker); + static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = { .ast = ocfs2_inode_ast_func, .bast = ocfs2_inode_bast_func, @@ -116,9 +145,6 @@ static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = { .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, @@ -140,6 +166,14 @@ static struct ocfs2_lock_res_ops ocfs2_rename_lops = { .unblock = ocfs2_unblock_osb_lock, }; +static struct ocfs2_lock_res_ops ocfs2_dentry_lops = { + .ast = ocfs2_dentry_ast_func, + .bast = ocfs2_dentry_bast_func, + .unlock_ast = ocfs2_unlock_ast_func, + .unblock = ocfs2_unblock_dentry_lock, + .post_unlock = ocfs2_dentry_post_unlock, +}; + static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres) { return lockres->l_type == OCFS2_LOCK_TYPE_META || @@ -172,6 +206,13 @@ static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres) return (struct inode *) lockres->l_priv; } +static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres) +{ + BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY); + + return (struct ocfs2_dentry_lock *)lockres->l_priv; +} + static int ocfs2_lock_create(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres, int level, @@ -204,22 +245,6 @@ 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, @@ -265,13 +290,9 @@ static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res) 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; @@ -319,9 +340,59 @@ void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, break; }; - ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, - OCFS2_I(inode)->ip_blkno, - inode->i_generation, ops, inode); + ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno, + inode->i_generation, res->l_name); + ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode); +} + +static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres) +{ + __be64 inode_blkno_be; + + memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], + sizeof(__be64)); + + return be64_to_cpu(inode_blkno_be); +} + +void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl, + u64 parent, struct inode *inode) +{ + int len; + u64 inode_blkno = OCFS2_I(inode)->ip_blkno; + __be64 inode_blkno_be = cpu_to_be64(inode_blkno); + struct ocfs2_lock_res *lockres = &dl->dl_lockres; + + ocfs2_lock_res_init_once(lockres); + + /* + * Unfortunately, the standard lock naming scheme won't work + * here because we have two 16 byte values to use. Instead, + * we'll stuff the inode number as a binary value. We still + * want error prints to show something without garbling the + * display, so drop a null byte in there before the inode + * number. A future version of OCFS2 will likely use all + * binary lock names. The stringified names have been a + * tremendous aid in debugging, but now that the debugfs + * interface exists, we can mangle things there if need be. + * + * NOTE: We also drop the standard "pad" value (the total lock + * name size stays the same though - the last part is all + * zeros due to the memset in ocfs2_lock_res_init_once() + */ + len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START, + "%c%016llx", + ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY), + (long long)parent); + + BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1)); + + memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be, + sizeof(__be64)); + + ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres, + OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops, + dl); } static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res, @@ -330,8 +401,9 @@ static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res, /* Superblock lockres doesn't come from a slab so we call init * once on it manually. */ ocfs2_lock_res_init_once(res); + ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO, + 0, res->l_name); ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER, - OCFS2_SUPER_BLOCK_BLKNO, 0, &ocfs2_super_lops, osb); } @@ -341,7 +413,8 @@ static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res, /* 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_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name); + ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME, &ocfs2_rename_lops, osb); } @@ -627,9 +700,10 @@ static void ocfs2_generic_bast_func(struct ocfs2_super *osb, ocfs2_schedule_blocked_lock(osb, lockres); spin_unlock_irqrestore(&lockres->l_lock, flags); + wake_up(&lockres->l_event); + ocfs2_kick_vote_thread(osb); - wake_up(&lockres->l_event); mlog_exit_void(); } @@ -690,9 +764,9 @@ static void ocfs2_generic_ast_func(struct ocfs2_lock_res *lockres, /* 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); + spin_unlock_irqrestore(&lockres->l_lock, flags); } static void ocfs2_super_ast_func(void *opaque) @@ -757,6 +831,27 @@ static void ocfs2_rename_bast_func(void *opaque, mlog_exit_void(); } +static void ocfs2_dentry_ast_func(void *opaque) +{ + struct ocfs2_lock_res *lockres = opaque; + + BUG_ON(!lockres); + + ocfs2_generic_ast_func(lockres, 1); +} + +static void ocfs2_dentry_bast_func(void *opaque, int level) +{ + struct ocfs2_lock_res *lockres = opaque; + struct ocfs2_dentry_lock *dl = lockres->l_priv; + struct ocfs2_super *osb = OCFS2_SB(dl->dl_inode->i_sb); + + mlog(0, "Dentry bast: level: %d, name: %s\n", level, + lockres->l_name); + + ocfs2_generic_bast_func(osb, lockres, level); +} + static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, int convert) { @@ -1076,10 +1171,11 @@ static void ocfs2_cluster_unlock(struct ocfs2_super *osb, mlog_exit_void(); } -static int ocfs2_create_new_inode_lock(struct inode *inode, - struct ocfs2_lock_res *lockres) +int ocfs2_create_new_lock(struct ocfs2_super *osb, + struct ocfs2_lock_res *lockres, + int ex) { - struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + int level = ex ? LKM_EXMODE : LKM_PRMODE; unsigned long flags; spin_lock_irqsave(&lockres->l_lock, flags); @@ -1087,7 +1183,7 @@ static int ocfs2_create_new_inode_lock(struct inode *inode, lockres_or_flags(lockres, OCFS2_LOCK_LOCAL); spin_unlock_irqrestore(&lockres->l_lock, flags); - return ocfs2_lock_create(osb, lockres, LKM_EXMODE, LKM_LOCAL); + return ocfs2_lock_create(osb, lockres, level, LKM_LOCAL); } /* Grants us an EX lock on the data and metadata resources, skipping @@ -1099,6 +1195,7 @@ static int ocfs2_create_new_inode_lock(struct inode *inode, int ocfs2_create_new_inode_locks(struct inode *inode) { int ret; + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); BUG_ON(!inode); BUG_ON(!ocfs2_inode_is_new(inode)); @@ -1115,22 +1212,19 @@ int ocfs2_create_new_inode_locks(struct inode *inode) * 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); + ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1); if (ret) { mlog_errno(ret); goto bail; } - ret = ocfs2_create_new_inode_lock(inode, - &OCFS2_I(inode)->ip_meta_lockres); + ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1); if (ret) { mlog_errno(ret); goto bail; } - ret = ocfs2_create_new_inode_lock(inode, - &OCFS2_I(inode)->ip_data_lockres); + ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1); if (ret) { mlog_errno(ret); goto bail; @@ -1809,6 +1903,34 @@ void ocfs2_rename_unlock(struct ocfs2_super *osb) ocfs2_cluster_unlock(osb, lockres, LKM_EXMODE); } +int ocfs2_dentry_lock(struct dentry *dentry, int ex) +{ + int ret; + int level = ex ? LKM_EXMODE : LKM_PRMODE; + struct ocfs2_dentry_lock *dl = dentry->d_fsdata; + struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); + + BUG_ON(!dl); + + if (ocfs2_is_hard_readonly(osb)) + return -EROFS; + + ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0); + if (ret < 0) + mlog_errno(ret); + + return ret; +} + +void ocfs2_dentry_unlock(struct dentry *dentry, int ex) +{ + int level = ex ? LKM_EXMODE : LKM_PRMODE; + struct ocfs2_dentry_lock *dl = dentry->d_fsdata; + struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); + + ocfs2_cluster_unlock(osb, &dl->dl_lockres, level); +} + /* 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. */ @@ -1939,9 +2061,16 @@ static int ocfs2_dlm_seq_show(struct seq_file *m, void *v) if (!lockres) return -EINVAL; - seq_printf(m, "0x%x\t" - "%.*s\t" - "%d\t" + seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION); + + if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY) + seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1, + lockres->l_name, + (unsigned int)ocfs2_get_dentry_lock_ino(lockres)); + else + seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name); + + seq_printf(m, "%d\t" "0x%lx\t" "0x%x\t" "0x%x\t" @@ -1949,8 +2078,6 @@ static int ocfs2_dlm_seq_show(struct seq_file *m, void *v) "%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, @@ -2311,25 +2438,21 @@ void ocfs2_mark_lockres_freeing(struct ocfs2_lock_res *lockres) spin_unlock_irqrestore(&lockres->l_lock, flags); } -static void ocfs2_drop_osb_locks(struct ocfs2_super *osb) +void ocfs2_simple_drop_lockres(struct ocfs2_super *osb, + struct ocfs2_lock_res *lockres) { - 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); + int ret; - status = ocfs2_drop_lock(osb, &osb->osb_rename_lockres, NULL); - if (status < 0) - mlog_errno(status); + ocfs2_mark_lockres_freeing(lockres); + ret = ocfs2_drop_lock(osb, lockres, NULL); + if (ret) + mlog_errno(ret); +} - mlog_exit(status); +static void ocfs2_drop_osb_locks(struct ocfs2_super *osb) +{ + ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres); + ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres); } static void ocfs2_meta_pre_drop(struct ocfs2_lock_res *lockres, void *data) @@ -2599,7 +2722,7 @@ leave: static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres, - int *requeue, + struct ocfs2_unblock_ctl *ctl, ocfs2_convert_worker_t *worker) { unsigned long flags; @@ -2615,7 +2738,7 @@ static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb, recheck: if (lockres->l_flags & OCFS2_LOCK_BUSY) { - *requeue = 1; + ctl->requeue = 1; ret = ocfs2_prepare_cancel_convert(osb, lockres); spin_unlock_irqrestore(&lockres->l_lock, flags); if (ret) { @@ -2631,7 +2754,7 @@ recheck: if ((lockres->l_blocking == LKM_EXMODE) && (lockres->l_ex_holders || lockres->l_ro_holders)) { spin_unlock_irqrestore(&lockres->l_lock, flags); - *requeue = 1; + ctl->requeue = 1; ret = 0; goto leave; } @@ -2641,7 +2764,7 @@ recheck: if (lockres->l_blocking == LKM_PRMODE && lockres->l_ex_holders) { spin_unlock_irqrestore(&lockres->l_lock, flags); - *requeue = 1; + ctl->requeue = 1; ret = 0; goto leave; } @@ -2659,7 +2782,10 @@ recheck: blocking = lockres->l_blocking; spin_unlock_irqrestore(&lockres->l_lock, flags); - worker(lockres, blocking); + ctl->unblock_action = worker(lockres, blocking); + + if (ctl->unblock_action == UNBLOCK_STOP_POST) + goto leave; spin_lock_irqsave(&lockres->l_lock, flags); if (blocking != lockres->l_blocking) { @@ -2669,7 +2795,7 @@ recheck: } downconvert: - *requeue = 0; + ctl->requeue = 0; new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking); ocfs2_prepare_downconvert(lockres, new_level); @@ -2680,14 +2806,12 @@ leave: return ret; } -static void ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, - int blocking) +static int 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; @@ -2708,11 +2832,11 @@ static void ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, filemap_fdatawait(mapping); } - mlog_exit_void(); + return UNBLOCK_CONTINUE; } int ocfs2_unblock_data(struct ocfs2_lock_res *lockres, - int *requeue) + struct ocfs2_unblock_ctl *ctl) { int status; struct inode *inode; @@ -2726,22 +2850,20 @@ int ocfs2_unblock_data(struct ocfs2_lock_res *lockres, mlog(0, "unblock inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); - status = ocfs2_generic_unblock_lock(osb, - lockres, - requeue, + status = ocfs2_generic_unblock_lock(osb, lockres, ctl, ocfs2_data_convert_worker); if (status < 0) mlog_errno(status); mlog(0, "inode %llu, requeue = %d\n", - (unsigned long long)OCFS2_I(inode)->ip_blkno, *requeue); + (unsigned long long)OCFS2_I(inode)->ip_blkno, ctl->requeue); mlog_exit(status); return status; } static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres, - int *requeue) + struct ocfs2_unblock_ctl *ctl) { int status; struct inode *inode; @@ -2753,9 +2875,7 @@ static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres, inode = ocfs2_lock_res_inode(lockres); status = ocfs2_generic_unblock_lock(OCFS2_SB(inode->i_sb), - lockres, - requeue, - NULL); + lockres, ctl, NULL); if (status < 0) mlog_errno(status); @@ -2763,9 +2883,8 @@ static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres, return status; } - -int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres, - int *requeue) +static int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres, + struct ocfs2_unblock_ctl *ctl) { int status; struct inode *inode; @@ -2777,21 +2896,165 @@ int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres, mlog(0, "unblock inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); - status = ocfs2_do_unblock_meta(inode, requeue); + status = ocfs2_do_unblock_meta(inode, &ctl->requeue); if (status < 0) mlog_errno(status); mlog(0, "inode %llu, requeue = %d\n", - (unsigned long long)OCFS2_I(inode)->ip_blkno, *requeue); + (unsigned long long)OCFS2_I(inode)->ip_blkno, ctl->requeue); mlog_exit(status); return status; } +/* + * Does the final reference drop on our dentry lock. Right now this + * happens in the vote thread, but we could choose to simplify the + * dlmglue API and push these off to the ocfs2_wq in the future. + */ +static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, + struct ocfs2_lock_res *lockres) +{ + struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); + ocfs2_dentry_lock_put(osb, dl); +} + +/* + * d_delete() matching dentries before the lock downconvert. + * + * At this point, any process waiting to destroy the + * dentry_lock due to last ref count is stopped by the + * OCFS2_LOCK_QUEUED flag. + * + * We have two potential problems + * + * 1) If we do the last reference drop on our dentry_lock (via dput) + * we'll wind up in ocfs2_release_dentry_lock(), waiting on + * the downconvert to finish. Instead we take an elevated + * reference and push the drop until after we've completed our + * unblock processing. + * + * 2) There might be another process with a final reference, + * waiting on us to finish processing. If this is the case, we + * detect it and exit out - there's no more dentries anyway. + */ +static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, + int blocking) +{ + struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); + struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode); + struct dentry *dentry; + unsigned long flags; + int extra_ref = 0; + + /* + * This node is blocking another node from getting a read + * lock. This happens when we've renamed within a + * directory. We've forced the other nodes to d_delete(), but + * we never actually dropped our lock because it's still + * valid. The downconvert code will retain a PR for this node, + * so there's no further work to do. + */ + if (blocking == LKM_PRMODE) + return UNBLOCK_CONTINUE; + + /* + * Mark this inode as potentially orphaned. The code in + * ocfs2_delete_inode() will figure out whether it actually + * needs to be freed or not. + */ + spin_lock(&oi->ip_lock); + oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED; + spin_unlock(&oi->ip_lock); + + /* + * Yuck. We need to make sure however that the check of + * OCFS2_LOCK_FREEING and the extra reference are atomic with + * respect to a reference decrement or the setting of that + * flag. + */ + spin_lock_irqsave(&lockres->l_lock, flags); + spin_lock(&dentry_attach_lock); + if (!(lockres->l_flags & OCFS2_LOCK_FREEING) + && dl->dl_count) { + dl->dl_count++; + extra_ref = 1; + } + spin_unlock(&dentry_attach_lock); + spin_unlock_irqrestore(&lockres->l_lock, flags); + + mlog(0, "extra_ref = %d\n", extra_ref); + + /* + * We have a process waiting on us in ocfs2_dentry_iput(), + * which means we can't have any more outstanding + * aliases. There's no need to do any more work. + */ + if (!extra_ref) + return UNBLOCK_CONTINUE; + + spin_lock(&dentry_attach_lock); + while (1) { + dentry = ocfs2_find_local_alias(dl->dl_inode, + dl->dl_parent_blkno, 1); + if (!dentry) + break; + spin_unlock(&dentry_attach_lock); + + mlog(0, "d_delete(%.*s);\n", dentry->d_name.len, + dentry->d_name.name); + + /* + * The following dcache calls may do an + * iput(). Normally we don't want that from the + * downconverting thread, but in this case it's ok + * because the requesting node already has an + * exclusive lock on the inode, so it can't be queued + * for a downconvert. + */ + d_delete(dentry); + dput(dentry); + + spin_lock(&dentry_attach_lock); + } + spin_unlock(&dentry_attach_lock); + + /* + * If we are the last holder of this dentry lock, there is no + * reason to downconvert so skip straight to the unlock. + */ + if (dl->dl_count == 1) + return UNBLOCK_STOP_POST; + + return UNBLOCK_CONTINUE_POST; +} + +static int ocfs2_unblock_dentry_lock(struct ocfs2_lock_res *lockres, + struct ocfs2_unblock_ctl *ctl) +{ + int ret; + struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); + struct ocfs2_super *osb = OCFS2_SB(dl->dl_inode->i_sb); + + mlog(0, "unblock dentry lock: %llu\n", + (unsigned long long)OCFS2_I(dl->dl_inode)->ip_blkno); + + ret = ocfs2_generic_unblock_lock(osb, + lockres, + ctl, + ocfs2_dentry_convert_worker); + if (ret < 0) + mlog_errno(ret); + + mlog(0, "requeue = %d, post = %d\n", ctl->requeue, ctl->unblock_action); + + return ret; +} + /* 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) + struct ocfs2_unblock_ctl *ctl) { int status; struct ocfs2_super *osb; @@ -2804,7 +3067,7 @@ static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres, status = ocfs2_generic_unblock_lock(osb, lockres, - requeue, + ctl, NULL); if (status < 0) mlog_errno(status); @@ -2817,7 +3080,7 @@ void ocfs2_process_blocked_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres) { int status; - int requeue = 0; + struct ocfs2_unblock_ctl ctl = {0, 0,}; unsigned long flags; /* Our reference to the lockres in this function can be @@ -2842,21 +3105,25 @@ void ocfs2_process_blocked_lock(struct ocfs2_super *osb, goto unqueue; spin_unlock_irqrestore(&lockres->l_lock, flags); - status = lockres->l_ops->unblock(lockres, &requeue); + status = lockres->l_ops->unblock(lockres, &ctl); if (status < 0) mlog_errno(status); spin_lock_irqsave(&lockres->l_lock, flags); unqueue: - if (lockres->l_flags & OCFS2_LOCK_FREEING || !requeue) { + if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.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"); + ctl.requeue ? "yes" : "no"); spin_unlock_irqrestore(&lockres->l_lock, flags); + if (ctl.unblock_action != UNBLOCK_CONTINUE + && lockres->l_ops->post_unlock) + lockres->l_ops->post_unlock(osb, lockres); + mlog_exit_void(); } |