diff options
| -rw-r--r-- | fs/ext4/ext4.h | 30 | ||||
| -rw-r--r-- | fs/ext4/mballoc.c | 10 |
2 files changed, 38 insertions, 2 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 70aa951ecb3..2e9a2036c11 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -952,6 +952,7 @@ struct ext4_sb_info { atomic_t s_mb_lost_chunks; atomic_t s_mb_preallocated; atomic_t s_mb_discarded; + atomic_t s_lock_busy; /* locality groups */ struct ext4_locality_group *s_locality_groups; @@ -1593,15 +1594,42 @@ struct ext4_group_info { #define EXT4_MB_GRP_NEED_INIT(grp) \ (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state))) +#define EXT4_MAX_CONTENTION 8 +#define EXT4_CONTENTION_THRESHOLD 2 + static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb, ext4_group_t group) { return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group); } +/* + * Returns true if the filesystem is busy enough that attempts to + * access the block group locks has run into contention. + */ +static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi) +{ + return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD); +} + static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group) { - spin_lock(ext4_group_lock_ptr(sb, group)); + spinlock_t *lock = ext4_group_lock_ptr(sb, group); + if (spin_trylock(lock)) + /* + * We're able to grab the lock right away, so drop the + * lock contention counter. + */ + atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0); + else { + /* + * The lock is busy, so bump the contention counter, + * and then wait on the spin lock. + */ + atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1, + EXT4_MAX_CONTENTION); + spin_lock(lock); + } } static inline void ext4_unlock_group(struct super_block *sb, diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 90a30ce822f..faf5bd056a9 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4191,9 +4191,17 @@ static void ext4_mb_group_or_file(struct ext4_allocation_context *ac) return; size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len; - isize = i_size_read(ac->ac_inode) >> bsbits; + isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1) + >> bsbits; size = max(size, isize); + if ((size == isize) && + !ext4_fs_is_busy(sbi) && + (atomic_read(&ac->ac_inode->i_writecount) == 0)) { + ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC; + return; + } + /* don't use group allocation for large files */ if (size >= sbi->s_mb_stream_request) { ac->ac_flags |= EXT4_MB_STREAM_ALLOC; |