+++ /dev/null
-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/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
-@@ -2088,8 +2157,16 @@ 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_feature_dir_index(inode->i_sb))
- 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
-@@ -52,6 +52,7 @@ 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;
-
- if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
-@@ -59,15 +60,22 @@ 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, EXT4_GET_BLOCKS_CREATE);
-- if (IS_ERR(bh))
-+ if (IS_ERR(bh)) {
-+ up(&ei->i_append_sem);
- return bh;
-+ }
- 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);
-@@ -247,7 +255,8 @@ static unsigned dx_node_limit(struct ino
- static struct dx_frame *dx_probe(struct ext4_filename *fname,
- struct inode *dir,
- struct dx_hash_info *hinfo,
-- struct dx_frame *frame);
-+ struct dx_frame *frame,
-+ struct htree_lock *lck);
- static void dx_release(struct dx_frame *frames);
- static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
- unsigned blocksize, struct dx_hash_info *hinfo,
-@@ -261,12 +270,13 @@ 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,
- struct ext4_filename *fname,
-- struct ext4_dir_entry_2 **res_dir);
-+ struct ext4_dir_entry_2 **res_dir, struct htree_lock *lck);
- static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
-- struct dentry *dentry, struct inode *inode);
-+ struct dentry *dentry, struct inode *inode,
-+ struct htree_lock *lck);
-
- /* checksumming functions */
- void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
-@@ -733,6 +743,227 @@ 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.
- *
-@@ -744,10 +975,11 @@ struct stats dx_show_entries(struct dx_h
- */
- static struct dx_frame *
- dx_probe(struct ext4_filename *fname, struct inode *dir,
-- struct dx_hash_info *hinfo, struct dx_frame *frame_in)
-+ struct dx_hash_info *hinfo, struct dx_frame *frame_in,
-+ struct htree_lock *lck)
- {
- 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 dx_frame *frame = frame_in;
- struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
-@@ -808,8 +1040,15 @@ dx_probe(struct ext4_filename *fname, st
-
- 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_inode(dir,
- "dx entry: count %u beyond limit %u",
- count, dx_get_limit(entries));
-@@ -847,8 +1086,70 @@ dx_probe(struct ext4_filename *fname, st
- dx_get_block(at)));
- frame->entries = entries;
- frame->at = at;
-- if (!indirect--)
-+
-+ 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--;
- frame++;
- frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
- if (IS_ERR(frame->bh)) {
-@@ -915,7 +1216,7 @@ 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;
-@@ -930,12 +1231,22 @@ 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--;
- }
-
-@@ -958,6 +1269,13 @@ 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);
-@@ -966,6 +1284,7 @@ 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;
- }
-
-@@ -1110,10 +1429,10 @@ int ext4_htree_fill_tree(struct file *di
- }
- hinfo.hash = start_hash;
- hinfo.minor_hash = 0;
-- frame = dx_probe(NULL, dir, &hinfo, frames);
-+ /* assume it's PR locked */
-+ frame = dx_probe(NULL, dir, &hinfo, frames, NULL);
- if (IS_ERR(frame))
- return PTR_ERR(frame);
--
- /* Add '.' and '..' from the htree header */
- if (!start_hash && !start_minor_hash) {
- de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
-@@ -1148,7 +1467,7 @@ 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;
-@@ -1372,10 +1691,10 @@ 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];
-@@ -1423,7 +1742,7 @@ static struct buffer_head * ext4_find_en
- goto restart;
- }
- if (is_dx(dir)) {
-- ret = ext4_dx_find_entry(dir, &fname, res_dir);
-+ ret = ext4_dx_find_entry(dir, &fname, res_dir, lck);
- /*
- * On success, or if the error was file not found,
- * return. Otherwise, fall back to doing a search the
-@@ -1433,6 +1752,7 @@ static struct buffer_head * ext4_find_en
- goto cleanup_and_exit;
- dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
- "falling back\n"));
-+ ext4_htree_safe_relock(lck);
- ret = NULL;
- }
- nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
-@@ -1534,10 +1854,12 @@ cleanup_and_exit:
- ext4_fname_free_filename(&fname);
- return ret;
- }
-+EXPORT_SYMBOL(__ext4_find_entry);
-
- static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
- struct ext4_filename *fname,
-- struct ext4_dir_entry_2 **res_dir)
-+ struct ext4_dir_entry_2 **res_dir,
-+ struct htree_lock *lck)
- {
- struct super_block * sb = dir->i_sb;
- struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
-@@ -1549,7 +1871,7 @@ static struct buffer_head * ext4_dx_find
- #ifdef CONFIG_EXT4_FS_ENCRYPTION
- *res_dir = NULL;
- #endif
-- frame = dx_probe(fname, dir, NULL, frames);
-+ frame = dx_probe(fname, dir, NULL, frames, lck);
- if (IS_ERR(frame))
- return (struct buffer_head *) frame;
- do {
-@@ -1571,7 +1893,7 @@ static struct buffer_head * ext4_dx_find
-
- /* Check to see if we should continue to search */
- retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
-- frames, NULL);
-+ frames, NULL, lck);
- if (retval < 0) {
- ext4_warning_inode(dir,
- "error %d reading directory index block",
-@@ -1762,8 +2084,9 @@ 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)
-+ struct buffer_head **bh, struct dx_frame *frames,
-+ struct dx_frame *frame, struct dx_hash_info *hinfo,
-+ struct htree_lock *lck)
- {
- unsigned blocksize = dir->i_sb->s_blocksize;
- unsigned count, continued;
-@@ -1825,8 +2148,14 @@ 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,
-@@ -1847,12 +2176,21 @@ static struct ext4_dir_entry_2 *do_split
- dxtrace(dx_show_leaf(dir, 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;
-@@ -2145,7 +2483,7 @@ static int make_indexed_dir(handle_t *ha
- if (retval)
- goto out_frames;
-
-- de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
-+ de = do_split(handle, dir, &bh2, frames, frame, &fname->hinfo, NULL);
- if (IS_ERR(de)) {
- retval = PTR_ERR(de);
- goto out_frames;
-@@ -2255,8 +2593,8 @@ 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 = d_inode(dentry->d_parent);
- struct buffer_head *bh = NULL;
-@@ -2297,9 +2635,10 @@ 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, &fname, dentry, inode);
-+ retval = ext4_dx_add_entry(handle, &fname, 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);
-@@ -2349,12 +2688,14 @@ out:
- 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 ext4_filename *fname,
-- struct dentry *dentry, struct inode *inode)
-+ struct dentry *dentry, struct inode *inode,
-+ struct htree_lock *lck)
- {
- struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
- struct dx_entry *entries, *at;
-@@ -2367,7 +2708,7 @@ static int ext4_dx_add_entry(handle_t *h
-
- again:
- restart = 0;
-- frame = dx_probe(fname, dir, NULL, frames);
-+ frame = dx_probe(fname, dir, NULL, frames, lck);
- if (IS_ERR(frame))
- return PTR_ERR(frame);
- entries = frame->entries;
-@@ -2397,6 +2738,11 @@ 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)) {
-@@ -2496,8 +2842,32 @@ 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, &fname->hinfo);
-+ de = do_split(handle, dir, &bh, frames, frame, &fname->hinfo, lck);
- if (IS_ERR(de)) {
- err = PTR_ERR(de);
- goto cleanup;
-@@ -2508,6 +2878,8 @@ again:
- 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
-@@ -875,6 +875,7 @@ static struct inode *ext4_alloc_inode(st
-
- ei->vfs_inode.i_version = 1;
- spin_lock_init(&ei->i_raw_lock);
-+ 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 / blobdiff