[PATCH v2] ext4: fix warning when turn on dioread_nolock and inline_data

[PATCH v2] ext4: fix warning when turn on dioread_nolock and inline_data

[yangerkun]

mkfs.ext4 -O inline_data /dev/vdb
mount -o dioread_nolock /dev/vdb /mnt
echo "some inline data..." >> /mnt/test-file
echo "some inline data..." >> /mnt/test-file
sync

The above script will trigger "WARN_ON(!io_end->handle && sbi->s_journal)"
because ext4_should_dioread_nolock() returns false for a file with inline
data. Move the check to a place after we have already removed the inline
data and prepared inode to write normal pages.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: yangerkun <yangerkun@huawei.com>
---
 fs/ext4/inode.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c7f77c6..3f2a366 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2769,15 +2769,6 @@ static int ext4_writepages(struct address_space *mapping,
 		goto out_writepages;
 	}
 
-	if (ext4_should_dioread_nolock(inode)) {
-		/*
-		 * We may need to convert up to one extent per block in
-		 * the page and we may dirty the inode.
-		 */
-		rsv_blocks = 1 + ext4_chunk_trans_blocks(inode,
-						PAGE_SIZE >> inode->i_blkbits);
-	}
-
 	/*
 	 * If we have inline data and arrive here, it means that
 	 * we will soon create the block for the 1st page, so
@@ -2796,6 +2787,15 @@ static int ext4_writepages(struct address_space *mapping,
 		ext4_journal_stop(handle);
 	}
 
+	if (ext4_should_dioread_nolock(inode)) {
+		/*
+		 * We may need to convert up to one extent per block in
+		 * the page and we may dirty the inode.
+		 */
+		rsv_blocks = 1 + ext4_chunk_trans_blocks(inode,
+						PAGE_SIZE >> inode->i_blkbits);
+	}
+
 	if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 		range_whole = 1;
 
-- 
2.7.4

Re: [PATCH v2] ext4: fix warning when turn on dioread_nolock and inline_data

[Theodore Y. Ts'o]

On Fri, Jul 05, 2019 at 04:01:34PM +0800, yangerkun wrote:
> mkfs.ext4 -O inline_data /dev/vdb
> mount -o dioread_nolock /dev/vdb /mnt
> echo "some inline data..." >> /mnt/test-file
> echo "some inline data..." >> /mnt/test-file
> sync
> 
> The above script will trigger "WARN_ON(!io_end->handle && sbi->s_journal)"
> because ext4_should_dioread_nolock() returns false for a file with inline
> data. Move the check to a place after we have already removed the inline
> data and prepared inode to write normal pages.
> 
> Reviewed-by: Jan Kara <jack@suse.cz>
> Signed-off-by: yangerkun <yangerkun@huawei.com>

Thanks, applied.

					- Ted