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Commit f9e4fb53 authored by Liu Bo's avatar Liu Bo Committed by Josef Bacik
Browse files

Btrfs: fix a bug when llseek for delalloc bytes behind prealloc extents 



xfstests case 285 complains.

It it because btrfs did not try to find unwritten delalloc
bytes(only dirty pages, not yet writeback) behind prealloc
extents, it ends up finding nothing while we're with SEEK_DATA.

Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent 1214b53f

fs/btrfs/file.c

+6 −3
Original line number Diff line number Diff line
@@ -2309,11 +2309,14 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int origin) 
					}

				}



				if (!test_bit(EXTENT_FLAG_PREALLOC,

					      &em->flags)) {

					*offset = start;

					free_extent_map(em);

					break;

				}

			}

		}



		start = em->start + em->len;

		last_end = em->start + em->len;

fs/btrfs/inode.c

+8 −3
Original line number Diff line number Diff line
@@ -5623,10 +5623,13 @@ struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *pag 
		return em;

	if (em) {

		/*

		 * if our em maps to a hole, there might

		 * actually be delalloc bytes behind it

		 * if our em maps to

		 * -  a hole or

		 * -  a pre-alloc extent,

		 * there might actually be delalloc bytes behind it.

		 */

		if (em->block_start != EXTENT_MAP_HOLE)

		if (em->block_start != EXTENT_MAP_HOLE &&

		    !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))

			return em;

		else

			hole_em = em;
@@ -5708,6 +5711,8 @@ struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *pag 
			 */

			em->block_start = hole_em->block_start;

			em->block_len = hole_len;

			if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))

				set_bit(EXTENT_FLAG_PREALLOC, &em->flags);

		} else {

			em->start = range_start;

			em->len = found;