Btrfs: btrfs_ioctl_clone: Truncate complete page after performing clone operation
In subpagesize-blocksize scenario, the "destination offset" argument passed to
the btrfs_ioctl_clone() can be aligned to sectorsize but may not be
necessarily aligned to the machine's page size. In such cases,
truncate_inode_pages_range() ends up zeroing out the partial page and future
read operations will return incorrect data. Hence this commit explicitly
rounds down the "destination offset" to the machine's page size.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 83c9ad3..709419c9 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3926,8 +3926,9 @@
* Truncate page cache pages so that future reads will see the cloned
* data immediately and not the previous data.
*/
- truncate_inode_pages_range(&inode->i_data, destoff,
- PAGE_CACHE_ALIGN(destoff + len) - 1);
+ truncate_inode_pages_range(&inode->i_data,
+ round_down(destoff, PAGE_CACHE_SIZE),
+ round_up(destoff + len, PAGE_CACHE_SIZE) - 1);
out_unlock:
if (!same_inode)
btrfs_double_inode_unlock(src, inode);