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| author | Dmitry Monakhov <dmonakhov@openvz.org> | 2012-09-29 00:41:21 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-09-29 00:41:21 -0400 |
| commit | 17335dcc471199717839b2fa3492ca36f70f1168 (patch) | |
| tree | 5f39f51868f60f8be94ca7e811d34bba443ef288 /fs/ext4/ext4.h | |
| parent | 28a535f9a0df060569dcc786e5bc2e1de43d7dc7 (diff) | |
| download | lwn-17335dcc471199717839b2fa3492ca36f70f1168.tar.gz lwn-17335dcc471199717839b2fa3492ca36f70f1168.zip | |
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 <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 17 |
1 files changed, 17 insertions, 0 deletions
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 */ |