X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=ldiskfs%2Fkernel_patches%2Fpatches%2Frhel6.8%2Fext4-pdirop.patch;fp=ldiskfs%2Fkernel_patches%2Fpatches%2Frhel6.8%2Fext4-pdirop.patch;h=0000000000000000000000000000000000000000;hp=25c051e07c8e7f94b9e21716a0170917ee2b9b7c;hb=501a46de3bd3681c322379a10416f75b759268f7;hpb=84fa16eda4aff8ebf2a557aeebe3401589c8a10e diff --git a/ldiskfs/kernel_patches/patches/rhel6.8/ext4-pdirop.patch b/ldiskfs/kernel_patches/patches/rhel6.8/ext4-pdirop.patch deleted file mode 100644 index 25c051e..0000000 --- a/ldiskfs/kernel_patches/patches/rhel6.8/ext4-pdirop.patch +++ /dev/null @@ -1,1873 +0,0 @@ -Index: linux-2.6.32-504.3.3.el6.x86_64/include/linux/htree_lock.h -=================================================================== ---- /dev/null -+++ linux-2.6.32-504.3.3.el6.x86_64/include/linux/htree_lock.h -@@ -0,0 +1,187 @@ -+/* -+ * include/linux/htree_lock.h -+ * -+ * Copyright (c) 2011, 2012, Intel Corporation. -+ * -+ * Author: Liang Zhen -+ */ -+ -+/* -+ * htree lock -+ * -+ * htree_lock is an advanced lock, it can support five lock modes (concept is -+ * taken from DLM) and it's a sleeping lock. -+ * -+ * most common use case is: -+ * - create a htree_lock_head for data -+ * - each thread (contender) creates it's own htree_lock -+ * - contender needs to call htree_lock(lock_node, mode) to protect data and -+ * call htree_unlock to release lock -+ * -+ * Also, there is advanced use-case which is more complex, user can have -+ * PW/PR lock on particular key, it's mostly used while user holding shared -+ * lock on the htree (CW, CR) -+ * -+ * htree_lock(lock_node, HTREE_LOCK_CR); lock the htree with CR -+ * htree_node_lock(lock_node, HTREE_LOCK_PR, key...); lock @key with PR -+ * ... -+ * htree_node_unlock(lock_node);; unlock the key -+ * -+ * Another tip is, we can have N-levels of this kind of keys, all we need to -+ * do is specifying N-levels while creating htree_lock_head, then we can -+ * lock/unlock a specific level by: -+ * htree_node_lock(lock_node, mode1, key1, level1...); -+ * do something; -+ * htree_node_lock(lock_node, mode1, key2, level2...); -+ * do something; -+ * htree_node_unlock(lock_node, level2); -+ * htree_node_unlock(lock_node, level1); -+ * -+ * NB: for multi-level, should be careful about locking order to avoid deadlock -+ */ -+ -+#ifndef _LINUX_HTREE_LOCK_H -+#define _LINUX_HTREE_LOCK_H -+ -+#include -+#include -+#include -+ -+/* -+ * Lock Modes -+ * more details can be found here: -+ * http://en.wikipedia.org/wiki/Distributed_lock_manager -+ */ -+typedef enum { -+ HTREE_LOCK_EX = 0, /* exclusive lock: incompatible with all others */ -+ HTREE_LOCK_PW, /* protected write: allows only CR users */ -+ HTREE_LOCK_PR, /* protected read: allow PR, CR users */ -+ HTREE_LOCK_CW, /* concurrent write: allow CR, CW users */ -+ HTREE_LOCK_CR, /* concurrent read: allow all but EX users */ -+ HTREE_LOCK_MAX, /* number of lock modes */ -+} htree_lock_mode_t; -+ -+#define HTREE_LOCK_NL HTREE_LOCK_MAX -+#define HTREE_LOCK_INVAL 0xdead10c -+ -+enum { -+ HTREE_HBITS_MIN = 2, -+ HTREE_HBITS_DEF = 14, -+ HTREE_HBITS_MAX = 32, -+}; -+ -+enum { -+ HTREE_EVENT_DISABLE = (0), -+ HTREE_EVENT_RD = (1 << HTREE_LOCK_PR), -+ HTREE_EVENT_WR = (1 << HTREE_LOCK_PW), -+ HTREE_EVENT_RDWR = (HTREE_EVENT_RD | HTREE_EVENT_WR), -+}; -+ -+struct htree_lock; -+ -+typedef void (*htree_event_cb_t)(void *target, void *event); -+ -+struct htree_lock_child { -+ struct list_head lc_list; /* granted list */ -+ htree_event_cb_t lc_callback; /* event callback */ -+ unsigned lc_events; /* event types */ -+}; -+ -+struct htree_lock_head { -+ unsigned long lh_lock; /* bits lock */ -+ /* blocked lock list (htree_lock) */ -+ struct list_head lh_blocked_list; -+ /* # key levels */ -+ u16 lh_depth; -+ /* hash bits for key and limit number of locks */ -+ u16 lh_hbits; -+ /* counters for blocked locks */ -+ u16 lh_nblocked[HTREE_LOCK_MAX]; -+ /* counters for granted locks */ -+ u16 lh_ngranted[HTREE_LOCK_MAX]; -+ /* private data */ -+ void *lh_private; -+ /* array of children locks */ -+ struct htree_lock_child lh_children[0]; -+}; -+ -+/* htree_lock_node_t is child-lock for a specific key (ln_value) */ -+struct htree_lock_node { -+ htree_lock_mode_t ln_mode; -+ /* major hash key */ -+ u16 ln_major_key; -+ /* minor hash key */ -+ u16 ln_minor_key; -+ struct list_head ln_major_list; -+ struct list_head ln_minor_list; -+ /* alive list, all locks (granted, blocked, listening) are on it */ -+ struct list_head ln_alive_list; -+ /* blocked list */ -+ struct list_head ln_blocked_list; -+ /* granted list */ -+ struct list_head ln_granted_list; -+ void *ln_ev_target; -+}; -+ -+struct htree_lock { -+ struct task_struct *lk_task; -+ struct htree_lock_head *lk_head; -+ void *lk_private; -+ unsigned lk_depth; -+ htree_lock_mode_t lk_mode; -+ struct list_head lk_blocked_list; -+ struct htree_lock_node lk_nodes[0]; -+}; -+ -+/* create a lock head, which stands for a resource */ -+struct htree_lock_head *htree_lock_head_alloc(unsigned depth, -+ unsigned hbits, unsigned priv); -+/* free a lock head */ -+void htree_lock_head_free(struct htree_lock_head *lhead); -+/* register event callback for child lock at level @depth */ -+void htree_lock_event_attach(struct htree_lock_head *lhead, unsigned depth, -+ unsigned events, htree_event_cb_t callback); -+/* create a lock handle, which stands for a thread */ -+struct htree_lock *htree_lock_alloc(unsigned depth, unsigned pbytes); -+/* free a lock handle */ -+void htree_lock_free(struct htree_lock *lck); -+/* lock htree, when @wait is true, 0 is returned if the lock can't -+ * be granted immediately */ -+int htree_lock_try(struct htree_lock *lck, struct htree_lock_head *lhead, -+ htree_lock_mode_t mode, int wait); -+/* unlock htree */ -+void htree_unlock(struct htree_lock *lck); -+/* unlock and relock htree with @new_mode */ -+int htree_change_lock_try(struct htree_lock *lck, -+ htree_lock_mode_t new_mode, int wait); -+void htree_change_mode(struct htree_lock *lck, htree_lock_mode_t mode); -+/* require child lock (key) of htree at level @dep, @event will be sent to all -+ * listeners on this @key while lock being granted */ -+int htree_node_lock_try(struct htree_lock *lck, htree_lock_mode_t mode, -+ u32 key, unsigned dep, int wait, void *event); -+/* release child lock at level @dep, this lock will listen on it's key -+ * if @event isn't NULL, event_cb will be called against @lck while granting -+ * any other lock at level @dep with the same key */ -+void htree_node_unlock(struct htree_lock *lck, unsigned dep, void *event); -+/* stop listening on child lock at level @dep */ -+void htree_node_stop_listen(struct htree_lock *lck, unsigned dep); -+/* for debug */ -+void htree_lock_stat_print(int depth); -+void htree_lock_stat_reset(void); -+ -+#define htree_lock(lck, lh, mode) htree_lock_try(lck, lh, mode, 1) -+#define htree_change_lock(lck, mode) htree_change_lock_try(lck, mode, 1) -+ -+#define htree_lock_mode(lck) ((lck)->lk_mode) -+ -+#define htree_node_lock(lck, mode, key, dep) \ -+ htree_node_lock_try(lck, mode, key, dep, 1, NULL) -+/* this is only safe in thread context of lock owner */ -+#define htree_node_is_granted(lck, dep) \ -+ ((lck)->lk_nodes[dep].ln_mode != HTREE_LOCK_INVAL && \ -+ (lck)->lk_nodes[dep].ln_mode != HTREE_LOCK_NL) -+/* this is only safe in thread context of lock owner */ -+#define htree_node_is_listening(lck, dep) \ -+ ((lck)->lk_nodes[dep].ln_mode == HTREE_LOCK_NL) -+ -+#endif -Index: linux-2.6.32-504.3.3.el6.x86_64/fs/ext4/htree_lock.c -=================================================================== ---- /dev/null -+++ linux-2.6.32-504.3.3.el6.x86_64/fs/ext4/htree_lock.c -@@ -0,0 +1,880 @@ -+/* -+ * fs/ext4/htree_lock.c -+ * -+ * Copyright (c) 2011, 2012, Intel Corporation. -+ * -+ * Author: Liang Zhen -+ */ -+#include -+#include -+#include -+#include -+ -+enum { -+ HTREE_LOCK_BIT_EX = (1 << HTREE_LOCK_EX), -+ HTREE_LOCK_BIT_PW = (1 << HTREE_LOCK_PW), -+ HTREE_LOCK_BIT_PR = (1 << HTREE_LOCK_PR), -+ HTREE_LOCK_BIT_CW = (1 << HTREE_LOCK_CW), -+ HTREE_LOCK_BIT_CR = (1 << HTREE_LOCK_CR), -+}; -+ -+enum { -+ HTREE_LOCK_COMPAT_EX = 0, -+ HTREE_LOCK_COMPAT_PW = HTREE_LOCK_COMPAT_EX | HTREE_LOCK_BIT_CR, -+ HTREE_LOCK_COMPAT_PR = HTREE_LOCK_COMPAT_PW | HTREE_LOCK_BIT_PR, -+ HTREE_LOCK_COMPAT_CW = HTREE_LOCK_COMPAT_PW | HTREE_LOCK_BIT_CW, -+ HTREE_LOCK_COMPAT_CR = HTREE_LOCK_COMPAT_CW | HTREE_LOCK_BIT_PR | -+ HTREE_LOCK_BIT_PW, -+}; -+ -+static int htree_lock_compat[] = { -+ [HTREE_LOCK_EX] HTREE_LOCK_COMPAT_EX, -+ [HTREE_LOCK_PW] HTREE_LOCK_COMPAT_PW, -+ [HTREE_LOCK_PR] HTREE_LOCK_COMPAT_PR, -+ [HTREE_LOCK_CW] HTREE_LOCK_COMPAT_CW, -+ [HTREE_LOCK_CR] HTREE_LOCK_COMPAT_CR, -+}; -+ -+/* max allowed htree-lock depth. -+ * We only need depth=3 for ext4 although user can have higher value. */ -+#define HTREE_LOCK_DEP_MAX 16 -+ -+#ifdef HTREE_LOCK_DEBUG -+ -+static char *hl_name[] = { -+ [HTREE_LOCK_EX] "EX", -+ [HTREE_LOCK_PW] "PW", -+ [HTREE_LOCK_PR] "PR", -+ [HTREE_LOCK_CW] "CW", -+ [HTREE_LOCK_CR] "CR", -+}; -+ -+/* lock stats */ -+struct htree_lock_node_stats { -+ unsigned long long blocked[HTREE_LOCK_MAX]; -+ unsigned long long granted[HTREE_LOCK_MAX]; -+ unsigned long long retried[HTREE_LOCK_MAX]; -+ unsigned long long events; -+}; -+ -+struct htree_lock_stats { -+ struct htree_lock_node_stats nodes[HTREE_LOCK_DEP_MAX]; -+ unsigned long long granted[HTREE_LOCK_MAX]; -+ unsigned long long blocked[HTREE_LOCK_MAX]; -+}; -+ -+static struct htree_lock_stats hl_stats; -+ -+void htree_lock_stat_reset(void) -+{ -+ memset(&hl_stats, 0, sizeof(hl_stats)); -+} -+ -+void htree_lock_stat_print(int depth) -+{ -+ int i; -+ int j; -+ -+ printk(KERN_DEBUG "HTREE LOCK STATS:\n"); -+ for (i = 0; i < HTREE_LOCK_MAX; i++) { -+ printk(KERN_DEBUG "[%s]: G [%10llu], B [%10llu]\n", -+ hl_name[i], hl_stats.granted[i], hl_stats.blocked[i]); -+ } -+ for (i = 0; i < depth; i++) { -+ printk(KERN_DEBUG "HTREE CHILD [%d] STATS:\n", i); -+ for (j = 0; j < HTREE_LOCK_MAX; j++) { -+ printk(KERN_DEBUG -+ "[%s]: G [%10llu], B [%10llu], R [%10llu]\n", -+ hl_name[j], hl_stats.nodes[i].granted[j], -+ hl_stats.nodes[i].blocked[j], -+ hl_stats.nodes[i].retried[j]); -+ } -+ } -+} -+ -+#define lk_grant_inc(m) do { hl_stats.granted[m]++; } while (0) -+#define lk_block_inc(m) do { hl_stats.blocked[m]++; } while (0) -+#define ln_grant_inc(d, m) do { hl_stats.nodes[d].granted[m]++; } while (0) -+#define ln_block_inc(d, m) do { hl_stats.nodes[d].blocked[m]++; } while (0) -+#define ln_retry_inc(d, m) do { hl_stats.nodes[d].retried[m]++; } while (0) -+#define ln_event_inc(d) do { hl_stats.nodes[d].events++; } while (0) -+ -+#else /* !DEBUG */ -+ -+void htree_lock_stat_reset(void) {} -+void htree_lock_stat_print(int depth) {} -+ -+#define lk_grant_inc(m) do {} while (0) -+#define lk_block_inc(m) do {} while (0) -+#define ln_grant_inc(d, m) do {} while (0) -+#define ln_block_inc(d, m) do {} while (0) -+#define ln_retry_inc(d, m) do {} while (0) -+#define ln_event_inc(d) do {} while (0) -+ -+#endif /* DEBUG */ -+ -+EXPORT_SYMBOL(htree_lock_stat_reset); -+EXPORT_SYMBOL(htree_lock_stat_print); -+ -+#define HTREE_DEP_ROOT (-1) -+ -+#define htree_spin_lock(lhead, dep) \ -+ bit_spin_lock((dep) + 1, &(lhead)->lh_lock) -+#define htree_spin_unlock(lhead, dep) \ -+ bit_spin_unlock((dep) + 1, &(lhead)->lh_lock) -+ -+#define htree_key_event_ignore(child, ln) \ -+ (!((child)->lc_events & (1 << (ln)->ln_mode))) -+ -+static int -+htree_key_list_empty(struct htree_lock_node *ln) -+{ -+ return list_empty(&ln->ln_major_list) && list_empty(&ln->ln_minor_list); -+} -+ -+static void -+htree_key_list_del_init(struct htree_lock_node *ln) -+{ -+ struct htree_lock_node *tmp = NULL; -+ -+ if (!list_empty(&ln->ln_minor_list)) { -+ tmp = list_entry(ln->ln_minor_list.next, -+ struct htree_lock_node, ln_minor_list); -+ list_del_init(&ln->ln_minor_list); -+ } -+ -+ if (list_empty(&ln->ln_major_list)) -+ return; -+ -+ if (tmp == NULL) { /* not on minor key list */ -+ list_del_init(&ln->ln_major_list); -+ } else { -+ BUG_ON(!list_empty(&tmp->ln_major_list)); -+ list_replace_init(&ln->ln_major_list, &tmp->ln_major_list); -+ } -+} -+ -+static void -+htree_key_list_replace_init(struct htree_lock_node *old, -+ struct htree_lock_node *new) -+{ -+ if (!list_empty(&old->ln_major_list)) -+ list_replace_init(&old->ln_major_list, &new->ln_major_list); -+ -+ if (!list_empty(&old->ln_minor_list)) -+ list_replace_init(&old->ln_minor_list, &new->ln_minor_list); -+} -+ -+static void -+htree_key_event_enqueue(struct htree_lock_child *child, -+ struct htree_lock_node *ln, int dep, void *event) -+{ -+ struct htree_lock_node *tmp; -+ -+ /* NB: ALWAYS called holding lhead::lh_lock(dep) */ -+ BUG_ON(ln->ln_mode == HTREE_LOCK_NL); -+ if (event == NULL || htree_key_event_ignore(child, ln)) -+ return; -+ -+ /* shouldn't be a very long list */ -+ list_for_each_entry(tmp, &ln->ln_alive_list, ln_alive_list) { -+ if (tmp->ln_mode == HTREE_LOCK_NL) { -+ ln_event_inc(dep); -+ if (child->lc_callback != NULL) -+ child->lc_callback(tmp->ln_ev_target, event); -+ } -+ } -+} -+ -+static int -+htree_node_lock_enqueue(struct htree_lock *newlk, struct htree_lock *curlk, -+ unsigned dep, int wait, void *event) -+{ -+ struct htree_lock_child *child = &newlk->lk_head->lh_children[dep]; -+ struct htree_lock_node *newln = &newlk->lk_nodes[dep]; -+ struct htree_lock_node *curln = &curlk->lk_nodes[dep]; -+ -+ /* NB: ALWAYS called holding lhead::lh_lock(dep) */ -+ /* NB: we only expect PR/PW lock mode at here, only these two modes are -+ * allowed for htree_node_lock(asserted in htree_node_lock_internal), -+ * NL is only used for listener, user can't directly require NL mode */ -+ if ((curln->ln_mode == HTREE_LOCK_NL) || -+ (curln->ln_mode != HTREE_LOCK_PW && -+ newln->ln_mode != HTREE_LOCK_PW)) { -+ /* no conflict, attach it on granted list of @curlk */ -+ if (curln->ln_mode != HTREE_LOCK_NL) { -+ list_add(&newln->ln_granted_list, -+ &curln->ln_granted_list); -+ } else { -+ /* replace key owner */ -+ htree_key_list_replace_init(curln, newln); -+ } -+ -+ list_add(&newln->ln_alive_list, &curln->ln_alive_list); -+ htree_key_event_enqueue(child, newln, dep, event); -+ ln_grant_inc(dep, newln->ln_mode); -+ return 1; /* still hold lh_lock */ -+ } -+ -+ if (!wait) { /* can't grant and don't want to wait */ -+ ln_retry_inc(dep, newln->ln_mode); -+ newln->ln_mode = HTREE_LOCK_INVAL; -+ return -1; /* don't wait and just return -1 */ -+ } -+ -+ newlk->lk_task = current; -+ set_current_state(TASK_UNINTERRUPTIBLE); -+ /* conflict, attach it on blocked list of curlk */ -+ list_add_tail(&newln->ln_blocked_list, &curln->ln_blocked_list); -+ list_add(&newln->ln_alive_list, &curln->ln_alive_list); -+ ln_block_inc(dep, newln->ln_mode); -+ -+ htree_spin_unlock(newlk->lk_head, dep); -+ /* wait to be given the lock */ -+ if (newlk->lk_task != NULL) -+ schedule(); -+ /* granted, no doubt, wake up will set me RUNNING */ -+ if (event == NULL || htree_key_event_ignore(child, newln)) -+ return 0; /* granted without lh_lock */ -+ -+ htree_spin_lock(newlk->lk_head, dep); -+ htree_key_event_enqueue(child, newln, dep, event); -+ return 1; /* still hold lh_lock */ -+} -+ -+/* -+ * get PR/PW access to particular tree-node according to @dep and @key, -+ * it will return -1 if @wait is false and can't immediately grant this lock. -+ * All listeners(HTREE_LOCK_NL) on @dep and with the same @key will get -+ * @event if it's not NULL. -+ * NB: ALWAYS called holding lhead::lh_lock -+ */ -+static int -+htree_node_lock_internal(struct htree_lock_head *lhead, struct htree_lock *lck, -+ htree_lock_mode_t mode, u32 key, unsigned dep, -+ int wait, void *event) -+{ -+ LIST_HEAD (list); -+ struct htree_lock *tmp; -+ struct htree_lock *tmp2; -+ u16 major; -+ u16 minor; -+ u8 reverse; -+ u8 ma_bits; -+ u8 mi_bits; -+ -+ BUG_ON(mode != HTREE_LOCK_PW && mode != HTREE_LOCK_PR); -+ BUG_ON(htree_node_is_granted(lck, dep)); -+ -+ key = hash_long(key, lhead->lh_hbits); -+ -+ mi_bits = lhead->lh_hbits >> 1; -+ ma_bits = lhead->lh_hbits - mi_bits; -+ -+ lck->lk_nodes[dep].ln_major_key = major = key & ((1U << ma_bits) - 1); -+ lck->lk_nodes[dep].ln_minor_key = minor = key >> ma_bits; -+ lck->lk_nodes[dep].ln_mode = mode; -+ -+ /* -+ * The major key list is an ordered list, so searches are started -+ * at the end of the list that is numerically closer to major_key, -+ * so at most half of the list will be walked (for well-distributed -+ * keys). The list traversal aborts early if the expected key -+ * location is passed. -+ */ -+ reverse = (major >= (1 << (ma_bits - 1))); -+ -+ if (reverse) { -+ list_for_each_entry_reverse(tmp, -+ &lhead->lh_children[dep].lc_list, -+ lk_nodes[dep].ln_major_list) { -+ if (tmp->lk_nodes[dep].ln_major_key == major) { -+ goto search_minor; -+ -+ } else if (tmp->lk_nodes[dep].ln_major_key < major) { -+ /* attach _after_ @tmp */ -+ list_add(&lck->lk_nodes[dep].ln_major_list, -+ &tmp->lk_nodes[dep].ln_major_list); -+ goto out_grant_major; -+ } -+ } -+ -+ list_add(&lck->lk_nodes[dep].ln_major_list, -+ &lhead->lh_children[dep].lc_list); -+ goto out_grant_major; -+ -+ } else { -+ list_for_each_entry(tmp, &lhead->lh_children[dep].lc_list, -+ lk_nodes[dep].ln_major_list) { -+ if (tmp->lk_nodes[dep].ln_major_key == major) { -+ goto search_minor; -+ -+ } else if (tmp->lk_nodes[dep].ln_major_key > major) { -+ /* insert _before_ @tmp */ -+ list_add_tail(&lck->lk_nodes[dep].ln_major_list, -+ &tmp->lk_nodes[dep].ln_major_list); -+ goto out_grant_major; -+ } -+ } -+ -+ list_add_tail(&lck->lk_nodes[dep].ln_major_list, -+ &lhead->lh_children[dep].lc_list); -+ goto out_grant_major; -+ } -+ -+ search_minor: -+ /* -+ * NB: minor_key list doesn't have a "head", @list is just a -+ * temporary stub for helping list searching, make sure it's removed -+ * after searching. -+ * minor_key list is an ordered list too. -+ */ -+ list_add_tail(&list, &tmp->lk_nodes[dep].ln_minor_list); -+ -+ reverse = (minor >= (1 << (mi_bits - 1))); -+ -+ if (reverse) { -+ list_for_each_entry_reverse(tmp2, &list, -+ lk_nodes[dep].ln_minor_list) { -+ if (tmp2->lk_nodes[dep].ln_minor_key == minor) { -+ goto out_enqueue; -+ -+ } else if (tmp2->lk_nodes[dep].ln_minor_key < minor) { -+ /* attach _after_ @tmp2 */ -+ list_add(&lck->lk_nodes[dep].ln_minor_list, -+ &tmp2->lk_nodes[dep].ln_minor_list); -+ goto out_grant_minor; -+ } -+ } -+ -+ list_add(&lck->lk_nodes[dep].ln_minor_list, &list); -+ -+ } else { -+ list_for_each_entry(tmp2, &list, -+ lk_nodes[dep].ln_minor_list) { -+ if (tmp2->lk_nodes[dep].ln_minor_key == minor) { -+ goto out_enqueue; -+ -+ } else if (tmp2->lk_nodes[dep].ln_minor_key > minor) { -+ /* insert _before_ @tmp2 */ -+ list_add_tail(&lck->lk_nodes[dep].ln_minor_list, -+ &tmp2->lk_nodes[dep].ln_minor_list); -+ goto out_grant_minor; -+ } -+ } -+ -+ list_add_tail(&lck->lk_nodes[dep].ln_minor_list, &list); -+ } -+ -+ out_grant_minor: -+ if (list.next == &lck->lk_nodes[dep].ln_minor_list) { -+ /* new lock @lck is the first one on minor_key list, which -+ * means it has the smallest minor_key and it should -+ * replace @tmp as minor_key owner */ -+ list_replace_init(&tmp->lk_nodes[dep].ln_major_list, -+ &lck->lk_nodes[dep].ln_major_list); -+ } -+ /* remove the temporary head */ -+ list_del(&list); -+ -+ out_grant_major: -+ ln_grant_inc(dep, lck->lk_nodes[dep].ln_mode); -+ return 1; /* granted with holding lh_lock */ -+ -+ out_enqueue: -+ list_del(&list); /* remove temprary head */ -+ return htree_node_lock_enqueue(lck, tmp2, dep, wait, event); -+} -+ -+/* -+ * release the key of @lck at level @dep, and grant any blocked locks. -+ * caller will still listen on @key if @event is not NULL, which means -+ * caller can see a event (by event_cb) while granting any lock with -+ * the same key at level @dep. -+ * NB: ALWAYS called holding lhead::lh_lock -+ * NB: listener will not block anyone because listening mode is HTREE_LOCK_NL -+ */ -+static void -+htree_node_unlock_internal(struct htree_lock_head *lhead, -+ struct htree_lock *curlk, unsigned dep, void *event) -+{ -+ struct htree_lock_node *curln = &curlk->lk_nodes[dep]; -+ struct htree_lock *grtlk = NULL; -+ struct htree_lock_node *grtln; -+ struct htree_lock *poslk; -+ struct htree_lock *tmplk; -+ -+ if (!htree_node_is_granted(curlk, dep)) -+ return; -+ -+ if (!list_empty(&curln->ln_granted_list)) { -+ /* there is another granted lock */ -+ grtlk = list_entry(curln->ln_granted_list.next, -+ struct htree_lock, -+ lk_nodes[dep].ln_granted_list); -+ list_del_init(&curln->ln_granted_list); -+ } -+ -+ if (grtlk == NULL && !list_empty(&curln->ln_blocked_list)) { -+ /* -+ * @curlk is the only granted lock, so we confirmed: -+ * a) curln is key owner (attached on major/minor_list), -+ * so if there is any blocked lock, it should be attached -+ * on curln->ln_blocked_list -+ * b) we always can grant the first blocked lock -+ */ -+ grtlk = list_entry(curln->ln_blocked_list.next, -+ struct htree_lock, -+ lk_nodes[dep].ln_blocked_list); -+ BUG_ON(grtlk->lk_task == NULL); -+ wake_up_process(grtlk->lk_task); -+ } -+ -+ if (event != NULL && -+ lhead->lh_children[dep].lc_events != HTREE_EVENT_DISABLE) { -+ curln->ln_ev_target = event; -+ curln->ln_mode = HTREE_LOCK_NL; /* listen! */ -+ } else { -+ curln->ln_mode = HTREE_LOCK_INVAL; -+ } -+ -+ if (grtlk == NULL) { /* I must be the only one locking this key */ -+ struct htree_lock_node *tmpln; -+ -+ BUG_ON(htree_key_list_empty(curln)); -+ -+ if (curln->ln_mode == HTREE_LOCK_NL) /* listening */ -+ return; -+ -+ /* not listening */ -+ if (list_empty(&curln->ln_alive_list)) { /* no more listener */ -+ htree_key_list_del_init(curln); -+ return; -+ } -+ -+ tmpln = list_entry(curln->ln_alive_list.next, -+ struct htree_lock_node, ln_alive_list); -+ -+ BUG_ON(tmpln->ln_mode != HTREE_LOCK_NL); -+ -+ htree_key_list_replace_init(curln, tmpln); -+ list_del_init(&curln->ln_alive_list); -+ -+ return; -+ } -+ -+ /* have a granted lock */ -+ grtln = &grtlk->lk_nodes[dep]; -+ if (!list_empty(&curln->ln_blocked_list)) { -+ /* only key owner can be on both lists */ -+ BUG_ON(htree_key_list_empty(curln)); -+ -+ if (list_empty(&grtln->ln_blocked_list)) { -+ list_add(&grtln->ln_blocked_list, -+ &curln->ln_blocked_list); -+ } -+ list_del_init(&curln->ln_blocked_list); -+ } -+ /* -+ * NB: this is the tricky part: -+ * We have only two modes for child-lock (PR and PW), also, -+ * only owner of the key (attached on major/minor_list) can be on -+ * both blocked_list and granted_list, so @grtlk must be one -+ * of these two cases: -+ * -+ * a) @grtlk is taken from granted_list, which means we've granted -+ * more than one lock so @grtlk has to be PR, the first blocked -+ * lock must be PW and we can't grant it at all. -+ * So even @grtlk is not owner of the key (empty blocked_list), -+ * we don't care because we can't grant any lock. -+ * b) we just grant a new lock which is taken from head of blocked -+ * list, and it should be the first granted lock, and it should -+ * be the first one linked on blocked_list. -+ * -+ * Either way, we can get correct result by iterating blocked_list -+ * of @grtlk, and don't have to bother on how to find out -+ * owner of current key. -+ */ -+ list_for_each_entry_safe(poslk, tmplk, &grtln->ln_blocked_list, -+ lk_nodes[dep].ln_blocked_list) { -+ if (grtlk->lk_nodes[dep].ln_mode == HTREE_LOCK_PW || -+ poslk->lk_nodes[dep].ln_mode == HTREE_LOCK_PW) -+ break; -+ /* grant all readers */ -+ list_del_init(&poslk->lk_nodes[dep].ln_blocked_list); -+ list_add(&poslk->lk_nodes[dep].ln_granted_list, -+ &grtln->ln_granted_list); -+ -+ BUG_ON(poslk->lk_task == NULL); -+ wake_up_process(poslk->lk_task); -+ } -+ -+ /* if @curln is the owner of this key, replace it with @grtln */ -+ if (!htree_key_list_empty(curln)) -+ htree_key_list_replace_init(curln, grtln); -+ -+ if (curln->ln_mode == HTREE_LOCK_INVAL) -+ list_del_init(&curln->ln_alive_list); -+} -+ -+/* -+ * it's just wrapper of htree_node_lock_internal, it returns 1 on granted -+ * and 0 only if @wait is false and can't grant it immediately -+ */ -+int -+htree_node_lock_try(struct htree_lock *lck, htree_lock_mode_t mode, -+ u32 key, unsigned dep, int wait, void *event) -+{ -+ struct htree_lock_head *lhead = lck->lk_head; -+ int rc; -+ -+ BUG_ON(dep >= lck->lk_depth); -+ BUG_ON(lck->lk_mode == HTREE_LOCK_INVAL); -+ -+ htree_spin_lock(lhead, dep); -+ rc = htree_node_lock_internal(lhead, lck, mode, key, dep, wait, event); -+ if (rc != 0) -+ htree_spin_unlock(lhead, dep); -+ return rc >= 0; -+} -+EXPORT_SYMBOL(htree_node_lock_try); -+ -+/* it's wrapper of htree_node_unlock_internal */ -+void -+htree_node_unlock(struct htree_lock *lck, unsigned dep, void *event) -+{ -+ struct htree_lock_head *lhead = lck->lk_head; -+ -+ BUG_ON(dep >= lck->lk_depth); -+ BUG_ON(lck->lk_mode == HTREE_LOCK_INVAL); -+ -+ htree_spin_lock(lhead, dep); -+ htree_node_unlock_internal(lhead, lck, dep, event); -+ htree_spin_unlock(lhead, dep); -+} -+EXPORT_SYMBOL(htree_node_unlock); -+ -+/* stop listening on child-lock level @dep */ -+void -+htree_node_stop_listen(struct htree_lock *lck, unsigned dep) -+{ -+ struct htree_lock_node *ln = &lck->lk_nodes[dep]; -+ struct htree_lock_node *tmp; -+ -+ BUG_ON(htree_node_is_granted(lck, dep)); -+ BUG_ON(!list_empty(&ln->ln_blocked_list)); -+ BUG_ON(!list_empty(&ln->ln_granted_list)); -+ -+ if (!htree_node_is_listening(lck, dep)) -+ return; -+ -+ htree_spin_lock(lck->lk_head, dep); -+ ln->ln_mode = HTREE_LOCK_INVAL; -+ ln->ln_ev_target = NULL; -+ -+ if (htree_key_list_empty(ln)) { /* not owner */ -+ list_del_init(&ln->ln_alive_list); -+ goto out; -+ } -+ -+ /* I'm the owner... */ -+ if (list_empty(&ln->ln_alive_list)) { /* no more listener */ -+ htree_key_list_del_init(ln); -+ goto out; -+ } -+ -+ tmp = list_entry(ln->ln_alive_list.next, -+ struct htree_lock_node, ln_alive_list); -+ -+ BUG_ON(tmp->ln_mode != HTREE_LOCK_NL); -+ htree_key_list_replace_init(ln, tmp); -+ list_del_init(&ln->ln_alive_list); -+ out: -+ htree_spin_unlock(lck->lk_head, dep); -+} -+EXPORT_SYMBOL(htree_node_stop_listen); -+ -+/* release all child-locks if we have any */ -+static void -+htree_node_release_all(struct htree_lock *lck) -+{ -+ int i; -+ -+ for (i = 0; i < lck->lk_depth; i++) { -+ if (htree_node_is_granted(lck, i)) -+ htree_node_unlock(lck, i, NULL); -+ else if (htree_node_is_listening(lck, i)) -+ htree_node_stop_listen(lck, i); -+ } -+} -+ -+/* -+ * obtain htree lock, it could be blocked inside if there's conflict -+ * with any granted or blocked lock and @wait is true. -+ * NB: ALWAYS called holding lhead::lh_lock -+ */ -+static int -+htree_lock_internal(struct htree_lock *lck, int wait) -+{ -+ struct htree_lock_head *lhead = lck->lk_head; -+ int granted = 0; -+ int blocked = 0; -+ int i; -+ -+ for (i = 0; i < HTREE_LOCK_MAX; i++) { -+ if (lhead->lh_ngranted[i] != 0) -+ granted |= 1 << i; -+ if (lhead->lh_nblocked[i] != 0) -+ blocked |= 1 << i; -+ } -+ if ((htree_lock_compat[lck->lk_mode] & granted) != granted || -+ (htree_lock_compat[lck->lk_mode] & blocked) != blocked) { -+ /* will block current lock even it just conflicts with any -+ * other blocked lock, so lock like EX wouldn't starve */ -+ if (!wait) -+ return -1; -+ lhead->lh_nblocked[lck->lk_mode]++; -+ lk_block_inc(lck->lk_mode); -+ -+ lck->lk_task = current; -+ list_add_tail(&lck->lk_blocked_list, &lhead->lh_blocked_list); -+ -+ set_current_state(TASK_UNINTERRUPTIBLE); -+ htree_spin_unlock(lhead, HTREE_DEP_ROOT); -+ /* wait to be given the lock */ -+ if (lck->lk_task != NULL) -+ schedule(); -+ /* granted, no doubt. wake up will set me RUNNING */ -+ return 0; /* without lh_lock */ -+ } -+ lhead->lh_ngranted[lck->lk_mode]++; -+ lk_grant_inc(lck->lk_mode); -+ return 1; -+} -+ -+/* release htree lock. NB: ALWAYS called holding lhead::lh_lock */ -+static void -+htree_unlock_internal(struct htree_lock *lck) -+{ -+ struct htree_lock_head *lhead = lck->lk_head; -+ struct htree_lock *tmp; -+ struct htree_lock *tmp2; -+ int granted = 0; -+ int i; -+ -+ BUG_ON(lhead->lh_ngranted[lck->lk_mode] == 0); -+ -+ lhead->lh_ngranted[lck->lk_mode]--; -+ lck->lk_mode = HTREE_LOCK_INVAL; -+ -+ for (i = 0; i < HTREE_LOCK_MAX; i++) { -+ if (lhead->lh_ngranted[i] != 0) -+ granted |= 1 << i; -+ } -+ list_for_each_entry_safe(tmp, tmp2, -+ &lhead->lh_blocked_list, lk_blocked_list) { -+ /* conflict with any granted lock? */ -+ if ((htree_lock_compat[tmp->lk_mode] & granted) != granted) -+ break; -+ -+ list_del_init(&tmp->lk_blocked_list); -+ -+ BUG_ON(lhead->lh_nblocked[tmp->lk_mode] == 0); -+ -+ lhead->lh_nblocked[tmp->lk_mode]--; -+ lhead->lh_ngranted[tmp->lk_mode]++; -+ granted |= 1 << tmp->lk_mode; -+ -+ BUG_ON(tmp->lk_task == NULL); -+ wake_up_process(tmp->lk_task); -+ } -+} -+ -+/* it's wrapper of htree_lock_internal and exported interface. -+ * It always return 1 with granted lock if @wait is true, it can return 0 -+ * if @wait is false and locking request can't be granted immediately */ -+int -+htree_lock_try(struct htree_lock *lck, struct htree_lock_head *lhead, -+ htree_lock_mode_t mode, int wait) -+{ -+ int rc; -+ -+ BUG_ON(lck->lk_depth > lhead->lh_depth); -+ BUG_ON(lck->lk_head != NULL); -+ BUG_ON(lck->lk_task != NULL); -+ -+ lck->lk_head = lhead; -+ lck->lk_mode = mode; -+ -+ htree_spin_lock(lhead, HTREE_DEP_ROOT); -+ rc = htree_lock_internal(lck, wait); -+ if (rc != 0) -+ htree_spin_unlock(lhead, HTREE_DEP_ROOT); -+ return rc >= 0; -+} -+EXPORT_SYMBOL(htree_lock_try); -+ -+/* it's wrapper of htree_unlock_internal and exported interface. -+ * It will release all htree_node_locks and htree_lock */ -+void -+htree_unlock(struct htree_lock *lck) -+{ -+ BUG_ON(lck->lk_head == NULL); -+ BUG_ON(lck->lk_mode == HTREE_LOCK_INVAL); -+ -+ htree_node_release_all(lck); -+ -+ htree_spin_lock(lck->lk_head, HTREE_DEP_ROOT); -+ htree_unlock_internal(lck); -+ htree_spin_unlock(lck->lk_head, HTREE_DEP_ROOT); -+ lck->lk_head = NULL; -+ lck->lk_task = NULL; -+} -+EXPORT_SYMBOL(htree_unlock); -+ -+/* change lock mode */ -+void -+htree_change_mode(struct htree_lock *lck, htree_lock_mode_t mode) -+{ -+ BUG_ON(lck->lk_mode == HTREE_LOCK_INVAL); -+ lck->lk_mode = mode; -+} -+EXPORT_SYMBOL(htree_change_mode); -+ -+/* release htree lock, and lock it again with new mode. -+ * This function will first release all htree_node_locks and htree_lock, -+ * then try to gain htree_lock with new @mode. -+ * It always return 1 with granted lock if @wait is true, it can return 0 -+ * if @wait is false and locking request can't be granted immediately */ -+int -+htree_change_lock_try(struct htree_lock *lck, htree_lock_mode_t mode, int wait) -+{ -+ struct htree_lock_head *lhead = lck->lk_head; -+ int rc; -+ -+ BUG_ON(lhead == NULL); -+ BUG_ON(lck->lk_mode == mode); -+ BUG_ON(lck->lk_mode == HTREE_LOCK_INVAL || mode == HTREE_LOCK_INVAL); -+ -+ htree_node_release_all(lck); -+ -+ htree_spin_lock(lhead, HTREE_DEP_ROOT); -+ htree_unlock_internal(lck); -+ lck->lk_mode = mode; -+ rc = htree_lock_internal(lck, wait); -+ if (rc != 0) -+ htree_spin_unlock(lhead, HTREE_DEP_ROOT); -+ return rc >= 0; -+} -+EXPORT_SYMBOL(htree_change_lock_try); -+ -+/* create a htree_lock head with @depth levels (number of child-locks), -+ * it is a per resoruce structure */ -+struct htree_lock_head * -+htree_lock_head_alloc(unsigned depth, unsigned hbits, unsigned priv) -+{ -+ struct htree_lock_head *lhead; -+ int i; -+ -+ if (depth > HTREE_LOCK_DEP_MAX) { -+ printk(KERN_ERR "%d is larger than max htree_lock depth %d\n", -+ depth, HTREE_LOCK_DEP_MAX); -+ return NULL; -+ } -+ -+ lhead = kzalloc(offsetof(struct htree_lock_head, -+ lh_children[depth]) + priv, GFP_NOFS); -+ if (lhead == NULL) -+ return NULL; -+ -+ if (hbits < HTREE_HBITS_MIN) -+ lhead->lh_hbits = HTREE_HBITS_MIN; -+ else if (hbits > HTREE_HBITS_MAX) -+ lhead->lh_hbits = HTREE_HBITS_MAX; -+ -+ lhead->lh_lock = 0; -+ lhead->lh_depth = depth; -+ INIT_LIST_HEAD(&lhead->lh_blocked_list); -+ if (priv > 0) { -+ lhead->lh_private = (void *)lhead + -+ offsetof(struct htree_lock_head, lh_children[depth]); -+ } -+ -+ for (i = 0; i < depth; i++) { -+ INIT_LIST_HEAD(&lhead->lh_children[i].lc_list); -+ lhead->lh_children[i].lc_events = HTREE_EVENT_DISABLE; -+ } -+ return lhead; -+} -+EXPORT_SYMBOL(htree_lock_head_alloc); -+ -+/* free the htree_lock head */ -+void -+htree_lock_head_free(struct htree_lock_head *lhead) -+{ -+ int i; -+ -+ BUG_ON(!list_empty(&lhead->lh_blocked_list)); -+ for (i = 0; i < lhead->lh_depth; i++) -+ BUG_ON(!list_empty(&lhead->lh_children[i].lc_list)); -+ kfree(lhead); -+} -+EXPORT_SYMBOL(htree_lock_head_free); -+ -+/* register event callback for @events of child-lock at level @dep */ -+void -+htree_lock_event_attach(struct htree_lock_head *lhead, unsigned dep, -+ unsigned events, htree_event_cb_t callback) -+{ -+ BUG_ON(lhead->lh_depth <= dep); -+ lhead->lh_children[dep].lc_events = events; -+ lhead->lh_children[dep].lc_callback = callback; -+} -+EXPORT_SYMBOL(htree_lock_event_attach); -+ -+/* allocate a htree_lock, which is per-thread structure, @pbytes is some -+ * extra-bytes as private data for caller */ -+struct htree_lock * -+htree_lock_alloc(unsigned depth, unsigned pbytes) -+{ -+ struct htree_lock *lck; -+ int i = offsetof(struct htree_lock, lk_nodes[depth]); -+ -+ if (depth > HTREE_LOCK_DEP_MAX) { -+ printk(KERN_ERR "%d is larger than max htree_lock depth %d\n", -+ depth, HTREE_LOCK_DEP_MAX); -+ return NULL; -+ } -+ lck = kzalloc(i + pbytes, GFP_NOFS); -+ if (lck == NULL) -+ return NULL; -+ -+ if (pbytes != 0) -+ lck->lk_private = (void *)lck + i; -+ lck->lk_mode = HTREE_LOCK_INVAL; -+ lck->lk_depth = depth; -+ INIT_LIST_HEAD(&lck->lk_blocked_list); -+ -+ for (i = 0; i < depth; i++) { -+ struct htree_lock_node *node = &lck->lk_nodes[i]; -+ -+ node->ln_mode = HTREE_LOCK_INVAL; -+ INIT_LIST_HEAD(&node->ln_major_list); -+ INIT_LIST_HEAD(&node->ln_minor_list); -+ INIT_LIST_HEAD(&node->ln_alive_list); -+ INIT_LIST_HEAD(&node->ln_blocked_list); -+ INIT_LIST_HEAD(&node->ln_granted_list); -+ } -+ -+ return lck; -+} -+EXPORT_SYMBOL(htree_lock_alloc); -+ -+/* free htree_lock node */ -+void -+htree_lock_free(struct htree_lock *lck) -+{ -+ BUG_ON(lck->lk_mode != HTREE_LOCK_INVAL); -+ kfree(lck); -+} -+EXPORT_SYMBOL(htree_lock_free); -Index: linux-2.6.32-504.3.3.el6.x86_64/fs/ext4/ext4.h -=================================================================== ---- linux-2.6.32-504.3.3.el6.x86_64.orig/fs/ext4/ext4.h -+++ linux-2.6.32-504.3.3.el6.x86_64/fs/ext4/ext4.h -@@ -27,6 +27,7 @@ - #include - #include - #include -+#include - #include - #include - #ifdef __KERNEL__ -@@ -1625,6 +1626,71 @@ ext4_dir_htree_level(struct super_block - EXT4_HTREE_LEVEL : EXT4_HTREE_LEVEL_COMPAT; - } - -+/* assume name-hash is protected by upper layer */ -+#define EXT4_HTREE_LOCK_HASH 0 -+ -+enum ext4_pdo_lk_types { -+#if EXT4_HTREE_LOCK_HASH -+ EXT4_LK_HASH, -+#endif -+ EXT4_LK_DX, /* index block */ -+ EXT4_LK_DE, /* directory entry block */ -+ EXT4_LK_SPIN, /* spinlock */ -+ EXT4_LK_MAX, -+}; -+ -+/* read-only bit */ -+#define EXT4_LB_RO(b) (1 << (b)) -+/* read + write, high bits for writer */ -+#define EXT4_LB_RW(b) ((1 << (b)) | (1 << (EXT4_LK_MAX + (b)))) -+ -+enum ext4_pdo_lock_bits { -+ /* DX lock bits */ -+ EXT4_LB_DX_RO = EXT4_LB_RO(EXT4_LK_DX), -+ EXT4_LB_DX = EXT4_LB_RW(EXT4_LK_DX), -+ /* DE lock bits */ -+ EXT4_LB_DE_RO = EXT4_LB_RO(EXT4_LK_DE), -+ EXT4_LB_DE = EXT4_LB_RW(EXT4_LK_DE), -+ /* DX spinlock bits */ -+ EXT4_LB_SPIN_RO = EXT4_LB_RO(EXT4_LK_SPIN), -+ EXT4_LB_SPIN = EXT4_LB_RW(EXT4_LK_SPIN), -+ /* accurate searching */ -+ EXT4_LB_EXACT = EXT4_LB_RO(EXT4_LK_MAX << 1), -+}; -+ -+enum ext4_pdo_lock_opc { -+ /* external */ -+ EXT4_HLOCK_READDIR = (EXT4_LB_DE_RO | EXT4_LB_DX_RO), -+ EXT4_HLOCK_LOOKUP = (EXT4_LB_DE_RO | EXT4_LB_SPIN_RO | -+ EXT4_LB_EXACT), -+ EXT4_HLOCK_DEL = (EXT4_LB_DE | EXT4_LB_SPIN_RO | -+ EXT4_LB_EXACT), -+ EXT4_HLOCK_ADD = (EXT4_LB_DE | EXT4_LB_SPIN_RO), -+ -+ /* internal */ -+ EXT4_HLOCK_LOOKUP_SAFE = (EXT4_LB_DE_RO | EXT4_LB_DX_RO | -+ EXT4_LB_EXACT), -+ EXT4_HLOCK_DEL_SAFE = (EXT4_LB_DE | EXT4_LB_DX_RO | EXT4_LB_EXACT), -+ EXT4_HLOCK_SPLIT = (EXT4_LB_DE | EXT4_LB_DX | EXT4_LB_SPIN), -+}; -+ -+extern struct htree_lock_head *ext4_htree_lock_head_alloc(unsigned hbits); -+#define ext4_htree_lock_head_free(lhead) htree_lock_head_free(lhead) -+ -+extern struct htree_lock *ext4_htree_lock_alloc(void); -+#define ext4_htree_lock_free(lck) htree_lock_free(lck) -+ -+extern void ext4_htree_lock(struct htree_lock *lck, -+ struct htree_lock_head *lhead, -+ struct inode *dir, unsigned flags); -+#define ext4_htree_unlock(lck) htree_unlock(lck) -+ -+extern struct buffer_head * __ext4_find_entry(struct inode *dir, -+ const struct qstr *d_name, -+ struct ext4_dir_entry_2 **res_dir, -+ struct htree_lock *lck); -+extern int __ext4_add_entry(handle_t *handle, struct dentry *dentry, -+ struct inode *inode, struct htree_lock *lck); - void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr, - ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp); - -Index: linux-2.6.32-504.3.3.el6.x86_64/fs/ext4/namei.c -=================================================================== ---- linux-2.6.32-504.3.3.el6.x86_64.orig/fs/ext4/namei.c -+++ linux-2.6.32-504.3.3.el6.x86_64/fs/ext4/namei.c -@@ -176,7 +176,7 @@ static struct dx_frame *dx_probe(const s - struct inode *dir, - struct dx_hash_info *hinfo, - struct dx_frame *frame, -- int *err); -+ struct htree_lock *lck, int *err); - static void dx_release(struct dx_frame *frames); - static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, - struct dx_hash_info *hinfo, struct dx_map_entry map[]); -@@ -189,13 +189,13 @@ static void dx_insert_block(struct dx_fr - static int ext4_htree_next_block(struct inode *dir, __u32 hash, - struct dx_frame *frame, - struct dx_frame *frames, -- __u32 *start_hash); -+ __u32 *start_hash, struct htree_lock *lck); - static struct buffer_head * ext4_dx_find_entry(struct inode *dir, - const struct qstr *d_name, - struct ext4_dir_entry_2 **res_dir, -- int *err); -+ struct htree_lock *lck, int *err); - static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, -- struct inode *inode); -+ struct inode *inode, struct htree_lock *lck); - - /* - * p is at least 6 bytes before the end of page -@@ -368,6 +368,225 @@ struct stats dx_show_entries(struct dx_h - } - #endif /* DX_DEBUG */ - -+/* private data for htree_lock */ -+struct ext4_dir_lock_data { -+ unsigned ld_flags; /* bits-map for lock types */ -+ unsigned ld_count; /* # entries of the last DX block */ -+ struct dx_entry ld_at_entry; /* copy of leaf dx_entry */ -+ struct dx_entry *ld_at; /* position of leaf dx_entry */ -+}; -+ -+#define ext4_htree_lock_data(l) ((struct ext4_dir_lock_data *)(l)->lk_private) -+#define ext4_find_entry(dir, name, dirent) __ext4_find_entry(dir, name, dirent, NULL) -+#define ext4_add_entry(handle, dentry, inode) __ext4_add_entry(handle, dentry, inode, NULL) -+ -+/* NB: ext4_lblk_t is 32 bits so we use high bits to identify invalid blk */ -+#define EXT4_HTREE_NODE_CHANGED (0xcafeULL << 32) -+ -+static void ext4_htree_event_cb(void *target, void *event) -+{ -+ u64 *block = (u64 *)target; -+ -+ if (*block == dx_get_block((struct dx_entry *)event)) -+ *block = EXT4_HTREE_NODE_CHANGED; -+} -+ -+struct htree_lock_head *ext4_htree_lock_head_alloc(unsigned hbits) -+{ -+ struct htree_lock_head *lhead; -+ -+ lhead = htree_lock_head_alloc(EXT4_LK_MAX, hbits, 0); -+ if (lhead != NULL) { -+ htree_lock_event_attach(lhead, EXT4_LK_SPIN, HTREE_EVENT_WR, -+ ext4_htree_event_cb); -+ } -+ return lhead; -+} -+EXPORT_SYMBOL(ext4_htree_lock_head_alloc); -+ -+struct htree_lock *ext4_htree_lock_alloc(void) -+{ -+ return htree_lock_alloc(EXT4_LK_MAX, -+ sizeof(struct ext4_dir_lock_data)); -+} -+EXPORT_SYMBOL(ext4_htree_lock_alloc); -+ -+static htree_lock_mode_t ext4_htree_mode(unsigned flags) -+{ -+ switch (flags) { -+ default: /* 0 or unknown flags require EX lock */ -+ return HTREE_LOCK_EX; -+ case EXT4_HLOCK_READDIR: -+ return HTREE_LOCK_PR; -+ case EXT4_HLOCK_LOOKUP: -+ return HTREE_LOCK_CR; -+ case EXT4_HLOCK_DEL: -+ case EXT4_HLOCK_ADD: -+ return HTREE_LOCK_CW; -+ } -+} -+ -+/* return PR for read-only operations, otherwise return EX */ -+static inline htree_lock_mode_t ext4_htree_safe_mode(unsigned flags) -+{ -+ int writer = (flags & EXT4_LB_DE) == EXT4_LB_DE; -+ -+ /* 0 requires EX lock */ -+ return (flags == 0 || writer) ? HTREE_LOCK_EX : HTREE_LOCK_PR; -+} -+ -+static int ext4_htree_safe_locked(struct htree_lock *lck) -+{ -+ int writer; -+ -+ if (lck == NULL || lck->lk_mode == HTREE_LOCK_EX) -+ return 1; -+ -+ writer = (ext4_htree_lock_data(lck)->ld_flags & EXT4_LB_DE) == -+ EXT4_LB_DE; -+ if (writer) /* all readers & writers are excluded? */ -+ return lck->lk_mode == HTREE_LOCK_EX; -+ -+ /* all writers are excluded? */ -+ return lck->lk_mode == HTREE_LOCK_PR || -+ lck->lk_mode == HTREE_LOCK_PW || -+ lck->lk_mode == HTREE_LOCK_EX; -+} -+ -+/* relock htree_lock with EX mode if it's change operation, otherwise -+ * relock it with PR mode. It's noop if PDO is disabled. */ -+static void ext4_htree_safe_relock(struct htree_lock *lck) -+{ -+ if (!ext4_htree_safe_locked(lck)) { -+ unsigned flags = ext4_htree_lock_data(lck)->ld_flags; -+ -+ htree_change_lock(lck, ext4_htree_safe_mode(flags)); -+ } -+} -+ -+void ext4_htree_lock(struct htree_lock *lck, struct htree_lock_head *lhead, -+ struct inode *dir, unsigned flags) -+{ -+ htree_lock_mode_t mode = is_dx(dir) ? ext4_htree_mode(flags) : -+ ext4_htree_safe_mode(flags); -+ -+ ext4_htree_lock_data(lck)->ld_flags = flags; -+ htree_lock(lck, lhead, mode); -+ if (!is_dx(dir)) -+ ext4_htree_safe_relock(lck); /* make sure it's safe locked */ -+} -+EXPORT_SYMBOL(ext4_htree_lock); -+ -+static int ext4_htree_node_lock(struct htree_lock *lck, struct dx_entry *at, -+ unsigned lmask, int wait, void *ev) -+{ -+ u32 key = (at == NULL) ? 0 : dx_get_block(at); -+ u32 mode; -+ -+ /* NOOP if htree is well protected or caller doesn't require the lock */ -+ if (ext4_htree_safe_locked(lck) || -+ !(ext4_htree_lock_data(lck)->ld_flags & lmask)) -+ return 1; -+ -+ mode = (ext4_htree_lock_data(lck)->ld_flags & lmask) == lmask ? -+ HTREE_LOCK_PW : HTREE_LOCK_PR; -+ while (1) { -+ if (htree_node_lock_try(lck, mode, key, ffz(~lmask), wait, ev)) -+ return 1; -+ if (!(lmask & EXT4_LB_SPIN)) /* not a spinlock */ -+ return 0; -+ cpu_relax(); /* spin until granted */ -+ } -+} -+ -+static int ext4_htree_node_locked(struct htree_lock *lck, unsigned lmask) -+{ -+ return ext4_htree_safe_locked(lck) || -+ htree_node_is_granted(lck, ffz(~lmask)); -+} -+ -+static void ext4_htree_node_unlock(struct htree_lock *lck, -+ unsigned lmask, void *buf) -+{ -+ /* NB: it's safe to call mutiple times or even it's not locked */ -+ if (!ext4_htree_safe_locked(lck) && -+ htree_node_is_granted(lck, ffz(~lmask))) -+ htree_node_unlock(lck, ffz(~lmask), buf); -+} -+ -+#define ext4_htree_dx_lock(lck, key) \ -+ ext4_htree_node_lock(lck, key, EXT4_LB_DX, 1, NULL) -+#define ext4_htree_dx_lock_try(lck, key) \ -+ ext4_htree_node_lock(lck, key, EXT4_LB_DX, 0, NULL) -+#define ext4_htree_dx_unlock(lck) \ -+ ext4_htree_node_unlock(lck, EXT4_LB_DX, NULL) -+#define ext4_htree_dx_locked(lck) \ -+ ext4_htree_node_locked(lck, EXT4_LB_DX) -+ -+static void ext4_htree_dx_need_lock(struct htree_lock *lck) -+{ -+ struct ext4_dir_lock_data *ld; -+ -+ if (ext4_htree_safe_locked(lck)) -+ return; -+ -+ ld = ext4_htree_lock_data(lck); -+ switch (ld->ld_flags) { -+ default: -+ return; -+ case EXT4_HLOCK_LOOKUP: -+ ld->ld_flags = EXT4_HLOCK_LOOKUP_SAFE; -+ return; -+ case EXT4_HLOCK_DEL: -+ ld->ld_flags = EXT4_HLOCK_DEL_SAFE; -+ return; -+ case EXT4_HLOCK_ADD: -+ ld->ld_flags = EXT4_HLOCK_SPLIT; -+ return; -+ } -+} -+ -+#define ext4_htree_de_lock(lck, key) \ -+ ext4_htree_node_lock(lck, key, EXT4_LB_DE, 1, NULL) -+#define ext4_htree_de_unlock(lck) \ -+ ext4_htree_node_unlock(lck, EXT4_LB_DE, NULL) -+ -+#define ext4_htree_spin_lock(lck, key, event) \ -+ ext4_htree_node_lock(lck, key, EXT4_LB_SPIN, 0, event) -+#define ext4_htree_spin_unlock(lck) \ -+ ext4_htree_node_unlock(lck, EXT4_LB_SPIN, NULL) -+#define ext4_htree_spin_unlock_listen(lck, p) \ -+ ext4_htree_node_unlock(lck, EXT4_LB_SPIN, p) -+ -+static void ext4_htree_spin_stop_listen(struct htree_lock *lck) -+{ -+ if (!ext4_htree_safe_locked(lck) && -+ htree_node_is_listening(lck, ffz(~EXT4_LB_SPIN))) -+ htree_node_stop_listen(lck, ffz(~EXT4_LB_SPIN)); -+} -+ -+enum { -+ DX_HASH_COL_IGNORE, /* ignore collision while probing frames */ -+ DX_HASH_COL_YES, /* there is collision and it does matter */ -+ DX_HASH_COL_NO, /* there is no collision */ -+}; -+ -+static int dx_probe_hash_collision(struct htree_lock *lck, -+ struct dx_entry *entries, -+ struct dx_entry *at, u32 hash) -+{ -+ if (!(lck && ext4_htree_lock_data(lck)->ld_flags & EXT4_LB_EXACT)) { -+ return DX_HASH_COL_IGNORE; /* don't care about collision */ -+ -+ } else if (at == entries + dx_get_count(entries) - 1) { -+ return DX_HASH_COL_IGNORE; /* not in any leaf of this DX */ -+ -+ } else { /* hash collision? */ -+ return ((dx_get_hash(at + 1) & ~1) == hash) ? -+ DX_HASH_COL_YES : DX_HASH_COL_NO; -+ } -+} -+ - /* - * Probe for a directory leaf block to search. - * -@@ -379,10 +598,11 @@ struct stats dx_show_entries(struct dx_h - */ - static struct dx_frame * - dx_probe(const struct qstr *d_name, struct inode *dir, -- struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err) -+ struct dx_hash_info *hinfo, struct dx_frame *frame_in, -+ struct htree_lock *lck, int *err) - { - unsigned count, indirect; -- struct dx_entry *at, *entries, *p, *q, *m; -+ struct dx_entry *at, *entries, *p, *q, *m, *dx = NULL; - struct dx_root_info * info; - struct buffer_head *bh; - struct dx_frame *frame = frame_in; -@@ -447,8 +667,15 @@ dx_probe(const struct qstr *d_name, stru - dxtrace(printk("Look up %x", hash)); - while (1) - { -+ if (indirect == 0) { /* the last index level */ -+ /* NB: ext4_htree_dx_lock() could be noop if -+ * DX-lock flag is not set for current operation */ -+ ext4_htree_dx_lock(lck, dx); -+ ext4_htree_spin_lock(lck, dx, NULL); -+ } - count = dx_get_count(entries); -- if (!count || count > dx_get_limit(entries)) { -+ if (count == 0 || count > dx_get_limit(entries)) { -+ ext4_htree_spin_unlock(lck); /* release spin */ - ext4_warning(dir->i_sb, - "dx entry: no count or count > limit"); - brelse(bh); -@@ -489,9 +716,73 @@ dx_probe(const struct qstr *d_name, stru - frame->bh = bh; - frame->entries = entries; - frame->at = at; -- if (!indirect--) return frame; -+ -+ if (indirect == 0) { /* the last index level */ -+ struct ext4_dir_lock_data *ld; -+ u64 myblock; -+ -+ /* By default we only lock DE-block, however, we will -+ * also lock the last level DX-block if: -+ * a) there is hash collision -+ * we will set DX-lock flag (a few lines below) -+ * and redo to lock DX-block -+ * see detail in dx_probe_hash_collision() -+ * b) it's a retry from splitting -+ * we need to lock the last level DX-block so nobody -+ * else can split any leaf blocks under the same -+ * DX-block, see detail in ext4_dx_add_entry() -+ */ -+ if (ext4_htree_dx_locked(lck)) { -+ /* DX-block is locked, just lock DE-block -+ * and return */ -+ ext4_htree_spin_unlock(lck); -+ if (!ext4_htree_safe_locked(lck)) -+ ext4_htree_de_lock(lck, frame->at); -+ return frame; -+ } -+ /* it's pdirop and no DX lock */ -+ if (dx_probe_hash_collision(lck, entries, at, hash) == -+ DX_HASH_COL_YES) { -+ /* found hash collision, set DX-lock flag -+ * and retry to abtain DX-lock */ -+ ext4_htree_spin_unlock(lck); -+ ext4_htree_dx_need_lock(lck); -+ continue; -+ } -+ ld = ext4_htree_lock_data(lck); -+ /* because I don't lock DX, so @at can't be trusted -+ * after I release spinlock so I have to save it */ -+ ld->ld_at = at; -+ ld->ld_at_entry = *at; -+ ld->ld_count = dx_get_count(entries); -+ -+ frame->at = &ld->ld_at_entry; -+ myblock = dx_get_block(at); -+ -+ /* NB: ordering locking */ -+ ext4_htree_spin_unlock_listen(lck, &myblock); -+ /* other thread can split this DE-block because: -+ * a) I don't have lock for the DE-block yet -+ * b) I released spinlock on DX-block -+ * if it happened I can detect it by listening -+ * splitting event on this DE-block */ -+ ext4_htree_de_lock(lck, frame->at); -+ ext4_htree_spin_stop_listen(lck); -+ -+ if (myblock == EXT4_HTREE_NODE_CHANGED) { -+ /* someone split this DE-block before -+ * I locked it, I need to retry and lock -+ * valid DE-block */ -+ ext4_htree_de_unlock(lck); -+ continue; -+ } -+ return frame; -+ } -+ dx = at; -+ indirect--; - if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err))) - goto fail2; -+ - at = entries = ((struct dx_node *) bh->b_data)->entries; - if (dx_get_limit(entries) != dx_node_limit (dir)) { - ext4_warning(dir->i_sb, -@@ -553,7 +844,7 @@ static void dx_release (struct dx_frame - static int ext4_htree_next_block(struct inode *dir, __u32 hash, - struct dx_frame *frame, - struct dx_frame *frames, -- __u32 *start_hash) -+ __u32 *start_hash, struct htree_lock *lck) - { - struct dx_frame *p; - struct buffer_head *bh; -@@ -568,12 +859,22 @@ static int ext4_htree_next_block(struct - * this loop, num_frames indicates the number of interior - * nodes need to be read. - */ -+ ext4_htree_de_unlock(lck); - while (1) { -- if (++(p->at) < p->entries + dx_get_count(p->entries)) -- break; -+ if (num_frames > 0 || ext4_htree_dx_locked(lck)) { -+ /* num_frames > 0 : -+ * DX block -+ * ext4_htree_dx_locked: -+ * frame->at is reliable pointer returned by dx_probe, -+ * otherwise dx_probe already knew no collision */ -+ if (++(p->at) < p->entries + dx_get_count(p->entries)) -+ break; -+ } - if (p == frames) - return 0; - num_frames++; -+ if (num_frames == 1) -+ ext4_htree_dx_unlock(lck); - p--; - } - -@@ -596,6 +897,13 @@ static int ext4_htree_next_block(struct - * block so no check is necessary - */ - while (num_frames--) { -+ if (num_frames == 0) { -+ /* it's not always necessary, we just don't want to -+ * detect hash collision again */ -+ ext4_htree_dx_need_lock(lck); -+ ext4_htree_dx_lock(lck, p->at); -+ } -+ - if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at), - 0, &err))) - return err; /* Failure */ -@@ -604,6 +912,7 @@ static int ext4_htree_next_block(struct - p->bh = bh; - p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; - } -+ ext4_htree_de_lock(lck, p->at); - return 1; - } - -@@ -696,10 +1005,10 @@ int ext4_htree_fill_tree(struct file *di - } - hinfo.hash = start_hash; - hinfo.minor_hash = 0; -- frame = dx_probe(NULL, dir, &hinfo, frames, &err); -+ /* assume it's PR locked */ -+ frame = dx_probe(NULL, dir, &hinfo, frames, NULL, &err); - if (!frame) - return err; -- - /* Add '.' and '..' from the htree header */ - if (!start_hash && !start_minor_hash) { - de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; -@@ -726,7 +1035,7 @@ int ext4_htree_fill_tree(struct file *di - count += ret; - hashval = ~0; - ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, -- frame, frames, &hashval); -+ frame, frames, &hashval, NULL); - *next_hash = hashval; - if (ret < 0) { - err = ret; -@@ -826,9 +1135,17 @@ static void dx_insert_block(struct dx_fr - - static void ext4_update_dx_flag(struct inode *inode) - { -+ /* Disable it for ldiskfs, because going from a DX directory to -+ * a non-DX directory while it is in use will completely break -+ * the htree-locking. -+ * If we really want to support this operation in the future, -+ * we need to exclusively lock the directory at here which will -+ * increase complexity of code */ -+#if 0 - if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb, - EXT4_FEATURE_COMPAT_DIR_INDEX)) - ext4_clear_inode_flag(inode, EXT4_INODE_INDEX); -+#endif - } - - /* -@@ -900,9 +1217,10 @@ static inline int search_dirblock(struct - * The returned buffer_head has ->b_count elevated. The caller is expected - * to brelse() it when appropriate. - */ --static struct buffer_head * ext4_find_entry (struct inode *dir, -+struct buffer_head * __ext4_find_entry(struct inode *dir, - const struct qstr *d_name, -- struct ext4_dir_entry_2 ** res_dir) -+ struct ext4_dir_entry_2 **res_dir, -+ struct htree_lock *lck) - { - struct super_block *sb; - struct buffer_head *bh_use[NAMEI_RA_SIZE]; -@@ -923,7 +1241,7 @@ static struct buffer_head * ext4_find_en - if (namelen > EXT4_NAME_LEN) - return NULL; - if (is_dx(dir)) { -- bh = ext4_dx_find_entry(dir, d_name, res_dir, &err); -+ bh = ext4_dx_find_entry(dir, d_name, res_dir, lck, &err); - /* - * On success, or if the error was file not found, - * return. Otherwise, fall back to doing a search the -@@ -933,6 +1251,7 @@ static struct buffer_head * ext4_find_en - return bh; - dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " - "falling back\n")); -+ ext4_htree_safe_relock(lck); - } - nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); - start = EXT4_I(dir)->i_dir_start_lookup; -@@ -1008,9 +1327,12 @@ cleanup_and_exit: - brelse(bh_use[ra_ptr]); - return ret; - } -+EXPORT_SYMBOL(__ext4_find_entry); - --static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name, -- struct ext4_dir_entry_2 **res_dir, int *err) -+static struct buffer_head * ext4_dx_find_entry(struct inode *dir, -+ const struct qstr *d_name, -+ struct ext4_dir_entry_2 **res_dir, -+ struct htree_lock *lck, int *err) - { - struct super_block * sb; - struct dx_hash_info hinfo; -@@ -1026,13 +1348,16 @@ static struct buffer_head * ext4_dx_find - sb = dir->i_sb; - /* NFS may look up ".." - look at dx_root directory block */ - if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){ -- if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err))) -+ if (!(frame = dx_probe(d_name, dir, &hinfo, frames, lck, err))) - return NULL; - } else { - frame = frames; - frame->bh = NULL; /* for dx_release() */ - frame->at = (struct dx_entry *)frames; /* hack for zero entry*/ - dx_set_block(frame->at, 0); /* dx_root block is 0 */ -+ /* "." and ".." are stored in root DX lock */ -+ ext4_htree_dx_need_lock(lck); -+ ext4_htree_dx_lock(lck, NULL); - } - hash = hinfo.hash; - do { -@@ -1061,7 +1386,7 @@ static struct buffer_head * ext4_dx_find - brelse(bh); - /* Check to see if we should continue to search */ - retval = ext4_htree_next_block(dir, hash, frame, -- frames, NULL); -+ frames, NULL, lck); - if (retval < 0) { - ext4_warning(sb, - "error reading index page in directory #%lu", -@@ -1244,8 +1569,9 @@ static struct ext4_dir_entry_2* dx_pack_ - * Returns pointer to de in block into which the new entry will be inserted. - */ - static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, -- struct buffer_head **bh,struct dx_frame *frame, -- struct dx_hash_info *hinfo, int *error) -+ struct buffer_head **bh, struct dx_frame *frames, -+ struct dx_frame *frame, struct dx_hash_info *hinfo, -+ struct htree_lock *lck, int *error) - { - unsigned blocksize = dir->i_sb->s_blocksize; - unsigned count, continued; -@@ -1302,7 +1628,14 @@ static struct ext4_dir_entry_2 *do_split - hash2, split, count-split)); - - /* Fancy dance to stay within two buffers */ -- de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize); -+ if (hinfo->hash < hash2) { -+ de2 = dx_move_dirents(data1, data2, map + split, -+ count - split, blocksize); -+ } else { -+ /* make sure we will add entry to the same block which -+ * we have already locked */ -+ de2 = dx_move_dirents(data1, data2, map, split, blocksize); -+ } - de = dx_pack_dirents(data1, blocksize); - de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de, - blocksize); -@@ -1311,13 +1644,21 @@ static struct ext4_dir_entry_2 *do_split - dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1)); - dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1)); - -- /* Which block gets the new entry? */ -- if (hinfo->hash >= hash2) -- { -- swap(*bh, bh2); -- de = de2; -+ ext4_htree_spin_lock(lck, frame > frames ? (frame - 1)->at : NULL, -+ frame->at); /* notify block is being split */ -+ if (hinfo->hash < hash2) { -+ dx_insert_block(frame, hash2 + continued, newblock); -+ -+ } else { -+ /* switch block number */ -+ dx_insert_block(frame, hash2 + continued, -+ dx_get_block(frame->at)); -+ dx_set_block(frame->at, newblock); -+ (frame->at)++; - } -- dx_insert_block(frame, hash2 + continued, newblock); -+ ext4_htree_spin_unlock(lck); -+ ext4_htree_dx_unlock(lck); -+ - err = ext4_handle_dirty_metadata(handle, dir, bh2); - if (err) - goto journal_error; -@@ -1558,8 +1899,8 @@ static int make_indexed_dir(handle_t *ha - retval = ext4_handle_dirty_metadata(handle, dir, bh); - if (retval) - goto out_frames; - -- de = do_split(handle,dir, &bh, frame, &hinfo, &retval); -+ de = do_split(handle,dir, &bh, frames, frame, &hinfo, NULL, &retval); - if (!de) - goto out_frames; - dx_release(frames); -@@ -1664,8 +2005,8 @@ out: - * may not sleep between calling this and putting something into - * the entry, as someone else might have used it while you slept. - */ --static int ext4_add_entry(handle_t *handle, struct dentry *dentry, -- struct inode *inode) -+int __ext4_add_entry(handle_t *handle, struct dentry *dentry, -+ struct inode *inode, struct htree_lock *lck) - { - struct inode *dir = dentry->d_parent->d_inode; - struct buffer_head *bh; -@@ -1684,9 +2025,10 @@ static int ext4_add_entry(handle_t *hand - if (dentry->d_name.len == 2 && - memcmp(dentry->d_name.name, "..", 2) == 0) - return ext4_update_dotdot(handle, dentry, inode); -- retval = ext4_dx_add_entry(handle, dentry, inode); -+ retval = ext4_dx_add_entry(handle, dentry, inode, lck); - if (!retval || (retval != ERR_BAD_DX_DIR)) - return retval; -+ ext4_htree_safe_relock(lck); - ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); - dx_fallback++; - ext4_mark_inode_dirty(handle, dir); -@@ -1717,12 +2059,13 @@ static int ext4_add_entry(handle_t *hand - brelse(bh); - return retval; - } -+EXPORT_SYMBOL(__ext4_add_entry); - - /* - * Returns 0 for success, or a negative error value - */ - static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, -- struct inode *inode) -+ struct inode *inode, struct htree_lock *lck) - { - struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; - struct dx_entry *entries, *at; -@@ -1736,7 +2079,7 @@ static int ext4_dx_add_entry(handle_t *h - - again: - restart = 0; -- frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err); -+ frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, lck, &err); - if (!frame) - return err; - entries = frame->entries; -@@ -1763,6 +2106,11 @@ again: - struct dx_node *node2; - struct buffer_head *bh2; - -+ if (!ext4_htree_safe_locked(lck)) { /* retry with EX lock */ -+ ext4_htree_safe_relock(lck); -+ restart = 1; -+ goto cleanup; -+ } - while (frame > frames) { - if (dx_get_count((frame - 1)->entries) < - dx_get_limit((frame - 1)->entries)) { -@@ -1860,16 +2208,43 @@ again: - restart = 1; - goto cleanup; - } -+ } else if (!ext4_htree_dx_locked(lck)) { -+ struct ext4_dir_lock_data *ld = ext4_htree_lock_data(lck); -+ -+ /* not well protected, require DX lock */ -+ ext4_htree_dx_need_lock(lck); -+ at = frame > frames ? (frame - 1)->at : NULL; -+ -+ /* NB: no risk of deadlock because it's just a try. -+ * -+ * NB: we check ld_count for twice, the first time before -+ * having DX lock, the second time after holding DX lock. -+ * -+ * NB: We never free blocks for directory so far, which -+ * means value returned by dx_get_count() should equal to -+ * ld->ld_count if nobody split any DE-block under @at, -+ * and ld->ld_at still points to valid dx_entry. */ -+ if ((ld->ld_count != dx_get_count(entries)) || -+ !ext4_htree_dx_lock_try(lck, at) || -+ (ld->ld_count != dx_get_count(entries))) { -+ restart = 1; -+ goto cleanup; -+ } -+ /* OK, I've got DX lock and nothing changed */ -+ frame->at = ld->ld_at; - } -- de = do_split(handle, dir, &bh, frame, &hinfo, &err); -+ de = do_split(handle, dir, &bh, frames, frame, &hinfo, lck, &err); - if (!de) - goto cleanup; -+ - err = add_dirent_to_buf(handle, dentry, inode, de, bh); - goto cleanup; - - journal_error: - ext4_std_error(dir->i_sb, err); - cleanup: -+ ext4_htree_dx_unlock(lck); -+ ext4_htree_de_unlock(lck); - if (bh) - brelse(bh); - dx_release(frames); -Index: linux-2.6.32-504.3.3.el6.x86_64/fs/ext4/Makefile -=================================================================== ---- linux-2.6.32-504.3.3.el6.x86_64.orig/fs/ext4/Makefile -+++ linux-2.6.32-504.3.3.el6.x86_64/fs/ext4/Makefile -@@ -6,6 +6,7 @@ obj-$(CONFIG_EXT4_FS) += ext4.o - - ext4-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \ - ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \ -+ htree_lock.o \ - ext4_jbd2.o migrate.o mballoc.o block_validity.o move_extent.o \ - mmp.o -