We need to call extent_range_clear_dirty_for_io()
on compression range to prevent application from changing
page content, while pages compressing.
extent_range_clear_dirty_for_io() run on each loop iteration,
"(end - start)" can be much (up to 1024 times) bigger
then compression range (BTRFS_MAX_UNCOMPRESSED).
That produce extra calls to page managment code.
Fix that behaviour by call extent_range_clear_dirty_for_io()
only once.
v1 -> v2:
- Make that more obviously and more safeprone
v2 -> v3:
- Rebased on:
Btrfs: compress_file_range() remove dead variable num_bytes
- Update change log
- Add comments
v3 -> v4:
- Rebased on: kdave for-next
- To avoid dirty bit clear/set behaviour change
call clear_bit once, istead of per compression range
Signed-off-by: Timofey Titovets <nefelim4ag@xxxxxxxxx>
---
fs/btrfs/inode.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b93fe05a39c7..5816dd3cb6e6 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -536,8 +536,10 @@ static noinline void compress_file_range(struct inode *inode,
* If the compression fails for any reason, we set the pages
* dirty again later on.
*/
- extent_range_clear_dirty_for_io(inode, start, end);
- redirty = 1;
+ if (!redirty) {
+ extent_range_clear_dirty_for_io(inode, start, end);
+ redirty = 1;
+ }
/* Compression level is applied here and only here */
ret = btrfs_compress_pages(
--
2.14.2
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
