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authorJosef Bacik <jbacik@fusionio.com>2013-07-02 10:38:02 -0400
committerJosef Bacik <jbacik@fusionio.com>2013-07-02 11:51:49 -0400
commit0e267c44c3a402d35111d1935be1167240b5b79f (patch)
treed09bc2390133da4ca34a4d11ca34ef524d03a87d /fs/btrfs
parent7fb7d76f96bfcbea25007d190ba828b18e13d29d (diff)
downloadop-kernel-dev-0e267c44c3a402d35111d1935be1167240b5b79f.zip
op-kernel-dev-0e267c44c3a402d35111d1935be1167240b5b79f.tar.gz
Btrfs: wait ordered range before doing direct io
My recent truncate patch uncovered this bug, but I can reproduce it without the truncate patch. If you mount with -o compress-force, do a direct write to some area, do a buffered write to some other area, and then do a direct read you will get the wrong data for where you did the buffered write. This is because the generic direct io helpers only call filemap_write_and_wait once, and for compression we need it twice. So to be safe add the btrfs_wait_ordered_range to the start of the direct io function to make sure any compressed writes have truly been written. This patch makes xfstests 130 pass when you mount with -o compress-force=lzo. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/inode.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 0a43d42..55dda87 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7270,8 +7270,16 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
atomic_inc(&inode->i_dio_count);
smp_mb__after_atomic_inc();
+ /*
+ * The generic stuff only does filemap_write_and_wait_range, which isn't
+ * enough if we've written compressed pages to this area, so we need to
+ * call btrfs_wait_ordered_range to make absolutely sure that any
+ * outstanding dirty pages are on disk.
+ */
+ count = iov_length(iov, nr_segs);
+ btrfs_wait_ordered_range(inode, offset, count);
+
if (rw & WRITE) {
- count = iov_length(iov, nr_segs);
/*
* If the write DIO is beyond the EOF, we need update
* the isize, but it is protected by i_mutex. So we can
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