[PATCH 02/11] ext4: Allow unaligned unlocked DAX IO

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Currently we don't allow unaligned writes without inode_lock. This is
because zeroing of partial blocks could cause data corruption for racing
unaligned writes to the same block. However DAX handles zeroing during
block allocation and thus zeroing of partial blocks cannot race. Allow
DAX unaligned IO to run without inode_lock.

Signed-off-by: Jan Kara <jack@xxxxxxx>
---
 fs/ext4/file.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index a6a7becb9465..55f8b922b76d 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -161,7 +161,8 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 	iocb->private = &overwrite;
 	/* Check whether we do a DIO overwrite or not */
-	if (o_direct && ext4_should_dioread_nolock(inode) && !unaligned_aio &&
+	if (((o_direct && !unaligned_aio) || IS_DAX(inode)) &&
+	    ext4_should_dioread_nolock(inode) &&
 	    ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from)))
 		overwrite = 1;
 
-- 
2.6.6

--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux