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@xxxxxxxxxxxxxxxxxx> --- fs/btrfs/ioctl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 8bbecda..4e11059 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3914,8 +3914,9 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, * 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); -- 2.1.0 -- 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
