-Single directory performance is a critical for HPC workloads. In a
-typical use case an application creates a separate output file for
-each node and task in a job. As nodes and tasks increase, hundreds
-of thousands of files may be created in a single directory within
-a short window of time.
-Today, both filename lookup and file system modifying operations
-(such as create and unlink) are protected with a single lock for
-an entire ldiskfs directory. PDO project will remove this
-bottleneck by introducing a parallel locking mechanism for entire
-ldiskfs directories. This work will enable multiple application
-threads to simultaneously lookup, create and unlink in parallel.
-
-This patch contains:
- - pdirops support for ldiskfs
- - integrate with osd-ldiskfs
-
-Index: linux-3.10.0-229.1.2.fc21.x86_64/include/linux/htree_lock.h
-===================================================================
---- /dev/null
-+++ linux-3.10.0-229.1.2.fc21.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 <liang@whamcloud.com>
-+ */
-+
-+/*
-+ * 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 <linux/list.h>
-+#include <linux/spinlock.h>
-+#include <linux/sched.h>
-+
-+/*
-+ * 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-3.10.0-229.1.2.fc21.x86_64/fs/ext4/htree_lock.c
-===================================================================
---- /dev/null
-+++ linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/htree_lock.c
-@@ -0,0 +1,891 @@
-+/*
-+ * fs/ext4/htree_lock.c
-+ *
-+ * Copyright (c) 2011, 2012, Intel Corporation.
-+ *
-+ * Author: Liang Zhen <liang@whamcloud.com>
-+ */
-+#include <linux/jbd2.h>
-+#include <linux/hash.h>
-+#include <linux/module.h>
-+#include <linux/htree_lock.h>
-+
-+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);
-+
-+retry:
-+ 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.
-+ * Since thread would be waken up accidentally,
-+ * so we need check lock whether granted or not again. */
-+ if (!list_empty(&lck->lk_blocked_list)) {
-+ htree_spin_lock(lhead, HTREE_DEP_ROOT);
-+ if (list_empty(&lck->lk_blocked_list)) {
-+ htree_spin_unlock(lhead, HTREE_DEP_ROOT);
-+ return 0;
-+ }
-+ goto retry;
-+ }
-+ 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-3.10.0-229.1.2.fc21.x86_64/fs/ext4/Makefile
-===================================================================
---- linux-3.10.0-229.1.2.fc21.x86_64.orig/fs/ext4/Makefile
-+++ linux-3.10.0-229.1.2.fc21.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 page-io.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 indirect.o extents_status.o xattr.o xattr_user.o \
- xattr_trusted.o inline.o
-Index: linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/ext4.h
-===================================================================
---- linux-3.10.0-229.1.2.fc21.x86_64.orig/fs/ext4/ext4.h
-+++ linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/ext4.h
-@@ -27,6 +27,7 @@
- #include <linux/mutex.h>
- #include <linux/timer.h>
- #include <linux/wait.h>
-+#include <linux/htree_lock.h>
- #include <linux/blockgroup_lock.h>
- #include <linux/percpu_counter.h>
- #include <linux/ratelimit.h>
-@@ -821,6 +822,9 @@ struct ext4_inode_info {
- __u32 i_dtime;
- ext4_fsblk_t i_file_acl;
-
-+ /* following fields for parallel directory operations -bzzz */
-+ struct semaphore i_append_sem;
-+
- /*
- * i_block_group is the number of the block group which contains
- * this file's inode. Constant across the lifetime of the inode,
-@@ -1846,6 +1850,71 @@ struct dx_hash_info
- */
- #define HASH_NB_ALWAYS 1
-
-+/* 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,
-+ int *inlined, struct htree_lock *lck);
-+extern int __ext4_add_entry(handle_t *handle, struct dentry *dentry,
-+ struct inode *inode, struct htree_lock *lck);
-
- /*
- * Describe an inode's exact location on disk and in memory
-@@ -2088,9 +2157,17 @@ void ext4_insert_dentry(struct inode *in
- const char *name, int namelen, void *data);
- static inline 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
- }
- static unsigned char ext4_filetype_table[] = {
- DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
-Index: linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/namei.c
-===================================================================
---- linux-3.10.0-229.1.2.fc21.x86_64.orig/fs/ext4/namei.c
-+++ linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/namei.c
-@@ -53,6 +53,7 @@ struct buffer_head *ext4_append(handle_t
- ext4_lblk_t *block)
- {
- struct buffer_head *bh;
-+ struct ext4_inode_info *ei = EXT4_I(inode);
- int err = 0;
-
- if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
-@@ -60,15 +61,22 @@ struct buffer_head *ext4_append(handle_t
- EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
- return ERR_PTR(-ENOSPC);
-
-+ /* with parallel dir operations all appends
-+ * have to be serialized -bzzz */
-+ down(&ei->i_append_sem);
-+
- *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
-
- bh = ext4_bread(handle, inode, *block, 1, &err);
-- if (!bh)
-+ if (!bh) {
-+ up(&ei->i_append_sem);
- return ERR_PTR(err);
-+ }
- inode->i_size += inode->i_sb->s_blocksize;
- EXT4_I(inode)->i_disksize = inode->i_size;
- BUFFER_TRACE(bh, "get_write_access");
- err = ext4_journal_get_write_access(handle, bh);
-+ up(&ei->i_append_sem);
- if (err) {
- brelse(bh);
- ext4_std_error(inode->i_sb, err);
-@@ -246,7 +254,7 @@ 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[]);
-@@ -259,13 +267,13 @@ 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);
-
- /* checksumming functions */
- void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
-@@ -668,6 +676,227 @@ 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, inline) \
-+ __ext4_find_entry(dir, name, dirent, inline, 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.
- *
-@@ -679,10 +908,11 @@ 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;
-@@ -750,8 +980,15 @@ 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);
-@@ -792,7 +1029,70 @@ 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--;
- bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
- if (IS_ERR(bh)) {
- *err = PTR_ERR(bh);
-@@ -860,7 +1160,7 @@ 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;
-@@ -875,12 +1175,22 @@ 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--;
- }
-
-@@ -903,6 +1213,13 @@ 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);
-+ }
-+
- bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
- if (IS_ERR(bh))
- return PTR_ERR(bh);
-@@ -911,6 +1228,7 @@ 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;
- }
-
-@@ -1013,10 +1331,10 @@ 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;
-@@ -1043,7 +1361,7 @@ 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;
-@@ -1236,10 +1554,10 @@ static int is_dx_internal_node(struct in
- * 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,
-- int *inlined)
-+ int *inlined, struct htree_lock *lck)
- {
- struct super_block *sb;
- struct buffer_head *bh_use[NAMEI_RA_SIZE];
-@@ -1283,7 +1601,7 @@ static struct buffer_head * ext4_find_en
- goto restart;
- }
- 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
-@@ -1297,6 +1615,7 @@ 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;
-@@ -1389,9 +1708,12 @@ 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 = dir->i_sb;
- struct dx_hash_info hinfo;
-@@ -1400,7 +1722,7 @@ static struct buffer_head * ext4_dx_find
- ext4_lblk_t block;
- int retval;
-
-- if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
-+ if (!(frame = dx_probe(d_name, dir, &hinfo, frames, lck, err)))
- return NULL;
- do {
- block = dx_get_block(frame->at);
-@@ -1424,7 +1746,7 @@ static struct buffer_head * ext4_dx_find
-
- /* Check to see if we should continue to search */
- retval = ext4_htree_next_block(dir, hinfo.hash, frame,
-- frames, NULL);
-+ frames, NULL, lck);
- if (retval < 0) {
- ext4_warning(sb,
- "error reading index page in directory #%lu",
-@@ -1583,8 +1905,9 @@ 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;
-@@ -1647,7 +1970,14 @@ 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 - csum_size) -
- (char *) de,
-@@ -1666,13 +1996,21 @@ 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_dirent_node(handle, dir, bh2);
- if (err)
- goto journal_error;
-@@ -1945,7 +2283,7 @@ static int make_indexed_dir(handle_t *ha
- ext4_handle_dirty_dx_node(handle, dir, frame->bh);
- ext4_handle_dirty_dirent_node(handle, dir, bh);
-
-- de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
-+ de = do_split(handle, dir, &bh, frames, frame, &hinfo, NULL, &retval);
- if (!de) {
- /*
- * Even if the block split failed, we have to properly write
-@@ -2051,8 +2389,8 @@ 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;
-@@ -2087,9 +2425,10 @@ 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))
- goto out;
-+ ext4_htree_safe_relock(lck);
- ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
- dx_fallback++;
- ext4_mark_inode_dirty(handle, dir);
-@@ -2129,12 +2468,13 @@ static int ext4_add_entry(handle_t *hand
- ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
- 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;
-@@ -2148,7 +2488,7 @@ 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;
-@@ -2178,6 +2518,11 @@ 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)) {
-@@ -2277,16 +2622,43 @@ again:
- restart = 1;
- goto journal_error;
- }
-+ } 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); /* this is a no-op if err == 0 */
- cleanup:
-+ ext4_htree_dx_unlock(lck);
-+ ext4_htree_de_unlock(lck);
- brelse(bh);
- dx_release(frames);
- /* @restart is true means htree-path has been changed, we need to
-Index: linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/super.c
-===================================================================
---- linux-3.10.0-229.1.2.fc21.x86_64.orig/fs/ext4/super.c
-+++ linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/super.c
-@@ -875,5 +875,6 @@ static struct inode *ext4_alloc_inode(st
-
- ei->vfs_inode.i_version = 1;
-+ sema_init(&ei->i_append_sem, 1);
- INIT_LIST_HEAD(&ei->i_prealloc_list);
- spin_lock_init(&ei->i_prealloc_lock);
- ext4_es_init_tree(&ei->i_es_tree);
git://git.whamcloud.com / fs / lustre-release.git / commitdiff