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| author | Dmitri Monakhov <dmonakhov@openvz.org> | 2009-01-07 01:40:04 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-07 02:59:06 +0300 |
| commit | 0f64415d42760379753e6088787ce3fd3e069509 (patch) | |
| tree | 85c9d3be88e56fb2d62558689744dbdd386cc745 /fs | |
| parent | 09f445e7f5107c91be12ed386350de6cd055e0a4 (diff) | |
| download | linux-0f64415d42760379753e6088787ce3fd3e069509.tar.xz | |
fs: truncate blocks outside i_size after O_DIRECT write error
In case of error extending write may have instantiated a few blocks
outside i_size. We need to trim these blocks. We have to do it
*regardless* to blocksize. At least ext2, ext3 and reiserfs interpret
(i_size < biggest block) condition as error. Fsck will complain about
wrong i_size. Then fsck will fix the error by changing i_size according
to the biggest block. This is bad because this blocks contain garbage
from previous write attempt. And result in data corruption.
####TESTCASE_BEGIN
$touch /mnt/test/BIG_FILE
## at this moment /mnt/test/BIG_FILE size and blocks equal to zero
open("/mnt/test/BIG_FILE", O_WRONLY|O_CREAT|O_DIRECT, 0666) = 3
write(3, "aaaaaaaaaaaa"..., 104857600) = -1 ENOSPC (No space left on device)
## size and block sould't be changed because write op failed.
$stat /mnt/test/BIG_FILE
File: `/mnt/test/BIG_FILE'
Size: 0 Blocks: 110896 IO Block: 1024 regular empty file
<<<<<<<<^^^^^^^^^^^^^^^^^^^^^^^^^^^^^file size is less than biggest block idx
Device: fe07h/65031d Inode: 14 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2007-01-24 20:03:38.000000000 +0300
Modify: 2007-01-24 20:03:38.000000000 +0300
Change: 2007-01-24 20:03:39.000000000 +0300
#fsck.ext3 -f /dev/VG/test
e2fsck 1.39 (29-May-2006)
Pass 1: Checking inodes, blocks, and sizes
Inode 14, i_size is 0, should be 56556544. Fix<y>? yes
Pass 2: Checking directory structure
....
#####TESTCASE_ENDdiff --git a/fs/direct-io.c b/fs/direct-io.c
index af0558d..4e88bea 100644
[akpm@linux-foundation.org: use i_size_read()]
Signed-off-by: Dmitri Monakhov <dmonakhov@openvz.org>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/direct-io.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c index af0558dbe8b7..b6d43908ff7a 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1209,6 +1209,19 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, retval = direct_io_worker(rw, iocb, inode, iov, offset, nr_segs, blkbits, get_block, end_io, dio); + /* + * In case of error extending write may have instantiated a few + * blocks outside i_size. Trim these off again for DIO_LOCKING. + * NOTE: DIO_NO_LOCK/DIO_OWN_LOCK callers have to handle this by + * it's own meaner. + */ + if (unlikely(retval < 0 && (rw & WRITE))) { + loff_t isize = i_size_read(inode); + + if (end > isize && dio_lock_type == DIO_LOCKING) + vmtruncate(inode, isize); + } + if (rw == READ && dio_lock_type == DIO_LOCKING) release_i_mutex = 0; |