From 17335dcc471199717839b2fa3492ca36f70f1168 Mon Sep 17 00:00:00 2001 From: Dmitry Monakhov Date: Sat, 29 Sep 2012 00:41:21 -0400 Subject: ext4: serialize dio nonlocked reads with defrag workers Inode's block defrag and ext4_change_inode_journal_flag() may affect nonlocked DIO reads result, so proper synchronization required. - Add missed inode_dio_wait() calls where appropriate - Check inode state under extra i_dio_count reference. Reviewed-by: Jan Kara Signed-off-by: Dmitry Monakhov Signed-off-by: "Theodore Ts'o" --- fs/ext4/ext4.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'fs/ext4/ext4.h') diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index edb049579420..1be2b4472a83 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1358,6 +1358,8 @@ enum { EXT4_STATE_DIO_UNWRITTEN, /* need convert on dio done*/ EXT4_STATE_NEWENTRY, /* File just added to dir */ EXT4_STATE_DELALLOC_RESERVED, /* blks already reserved for delalloc */ + EXT4_STATE_DIOREAD_LOCK, /* Disable support for dio read + nolocking */ }; #define EXT4_INODE_BIT_FNS(name, field, offset) \ @@ -2469,6 +2471,21 @@ static inline void set_bitmap_uptodate(struct buffer_head *bh) set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state); } +/* + * Disable DIO read nolock optimization, so new dioreaders will be forced + * to grab i_mutex + */ +static inline void ext4_inode_block_unlocked_dio(struct inode *inode) +{ + ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK); + smp_mb(); +} +static inline void ext4_inode_resume_unlocked_dio(struct inode *inode) +{ + smp_mb(); + ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK); +} + #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) /* For ioend & aio unwritten conversion wait queues */ -- cgit v1.2.3-58-ga151