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author | Dmitry Monakhov <dmonakhov@openvz.org> | 2012-09-29 00:41:21 -0400 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2012-09-29 00:41:21 -0400 |
commit | 17335dcc471199717839b2fa3492ca36f70f1168 (patch) | |
tree | 5f39f51868f60f8be94ca7e811d34bba443ef288 /fs/ext4 | |
parent | 28a535f9a0df060569dcc786e5bc2e1de43d7dc7 (diff) | |
download | linux-3.10-17335dcc471199717839b2fa3492ca36f70f1168.tar.gz linux-3.10-17335dcc471199717839b2fa3492ca36f70f1168.tar.bz2 linux-3.10-17335dcc471199717839b2fa3492ca36f70f1168.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')
-rw-r--r-- | fs/ext4/ext4.h | 17 | ||||
-rw-r--r-- | fs/ext4/indirect.c | 14 | ||||
-rw-r--r-- | fs/ext4/inode.c | 5 | ||||
-rw-r--r-- | fs/ext4/move_extent.c | 8 |
4 files changed, 44 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index edb04957942..1be2b4472a8 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 */ diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index 61f13e57975..8d849dae842 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -810,11 +810,25 @@ retry: if (unlikely(!list_empty(&ei->i_completed_io_list))) ext4_flush_completed_IO(inode); + /* + * Nolock dioread optimization may be dynamically disabled + * via ext4_inode_block_unlocked_dio(). Check inode's state + * while holding extra i_dio_count ref. + */ + atomic_inc(&inode->i_dio_count); + smp_mb(); + if (unlikely(ext4_test_inode_state(inode, + EXT4_STATE_DIOREAD_LOCK))) { + inode_dio_done(inode); + goto locked; + } ret = __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, offset, nr_segs, ext4_get_block, NULL, NULL, 0); + inode_dio_done(inode); } else { +locked: ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, ext4_get_block); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 09d0488e9a1..bdd399bc2ab 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4720,6 +4720,10 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val) return err; } + /* Wait for all existing dio workers */ + ext4_inode_block_unlocked_dio(inode); + inode_dio_wait(inode); + jbd2_journal_lock_updates(journal); /* @@ -4739,6 +4743,7 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val) ext4_set_aops(inode); jbd2_journal_unlock_updates(journal); + ext4_inode_resume_unlocked_dio(inode); /* Finally we can mark the inode as dirty. */ diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index 8076b96b529..292daeeed45 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -1323,6 +1323,12 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, /* Protect orig and donor inodes against a truncate */ mext_inode_double_lock(orig_inode, donor_inode); + /* Wait for all existing dio workers */ + ext4_inode_block_unlocked_dio(orig_inode); + ext4_inode_block_unlocked_dio(donor_inode); + inode_dio_wait(orig_inode); + inode_dio_wait(donor_inode); + /* Protect extent tree against block allocations via delalloc */ double_down_write_data_sem(orig_inode, donor_inode); /* Check the filesystem environment whether move_extent can be done */ @@ -1521,6 +1527,8 @@ out: kfree(holecheck_path); } double_up_write_data_sem(orig_inode, donor_inode); + ext4_inode_resume_unlocked_dio(orig_inode); + ext4_inode_resume_unlocked_dio(donor_inode); mext_inode_double_unlock(orig_inode, donor_inode); return ret; |