udf: Fix off-by-one error when discarding preallocation

[ Upstream commit 490a849b4a3d6e9bd67f9aa4385502dadbb70a32 ]

The condition determining whether the preallocation can be used had
an off-by-one error so we didn't discard preallocation when new
allocation was just following it. This can then confuse code in
inode_getblk().

CC: stable@vger.kernel.org
Fixes: 189b02ac597c ("udf: Discard preallocation before extending file with a hole")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 259152a08852baf6d444d83481ba7d49a81c8f26..a4e875b61f8958a6922a42971f5a566c48f8b306 100644 (file)
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -443,7 +443,7 @@ static int udf_get_block(struct inode *inode, sector_t block,
         * Block beyond EOF and prealloc extents? Just discard preallocation
         * as it is not useful and complicates things.
         */
-       if (((loff_t)block) << inode->i_blkbits > iinfo->i_lenExtents)
+       if (((loff_t)block) << inode->i_blkbits >= iinfo->i_lenExtents)
                udf_discard_prealloc(inode);
        udf_clear_extent_cache(inode);
        phys = inode_getblk(inode, block, &err, &new);