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authorDmitri Monakhov <dmonakhov@openvz.org>2009-01-06 23:40:04 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-07 00:59:06 +0100
commit0f64415d42760379753e6088787ce3fd3e069509 (patch)
tree85c9d3be88e56fb2d62558689744dbdd386cc745 /fs
parentmm: kill zone_is_near_oom() (diff)
downloadlinux-0f64415d42760379753e6088787ce3fd3e069509.tar.xz
linux-0f64415d42760379753e6088787ce3fd3e069509.zip
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.c13
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;