Commit d52a1365 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: selftests: remove impossible inline extent at non-zero file offset 



In our inode-tests.c, we create an inline offset at file offset 5, which
is no longer possible since the introduction of tree-checker.

Thus I don't think we should spend time maintaining some corner cases
which are already ruled out by tree-checker.

So this patch will:

- Change the inline extent to start at file offset 0

  Also change its length to 6 to cover the original length

- Add an extra ASSERT() for btrfs_add_extent_mapping()

  This is to make sure tree-checker is working correctly.

- Update the inode selftest

Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent aa5d3003

fs/btrfs/extent_map.c

+7 −0
Original line number Diff line number Diff line
@@ -638,6 +638,13 @@ int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info, 
	int ret;

	struct extent_map *em = *em_in;



	/*

	 * Tree-checker should have rejected any inline extent with non-zero

	 * file offset. Here just do a sanity check.

	 */

	if (em->block_start == EXTENT_MAP_INLINE)

		ASSERT(em->start == 0);



	ret = add_extent_mapping(em_tree, em, 0);

	/* it is possible that someone inserted the extent into the tree

	 * while we had the lock dropped.  It is also possible that

fs/btrfs/tests/inode-tests.c

+19 −38
Original line number Diff line number Diff line
@@ -73,8 +73,8 @@ static void insert_inode_item_key(struct btrfs_root *root) 
 * diagram of how the extents will look though this may not be possible we still

 * want to make sure everything acts normally (the last number is not inclusive)

 *

 * [0 - 5][5 -  6][     6 - 4096     ][ 4096 - 4100][4100 - 8195][8195 - 12291]

 * [hole ][inline][hole but no extent][  hole   ][   regular ][regular1 split]

 * [0  - 6][     6 - 4096     ][ 4096 - 4100][4100 - 8195][8195  -  12291]

 * [inline][hole but no extent][    hole    ][   regular ][regular1 split]

 *

 * [12291 - 16387][16387 - 24579][24579 - 28675][ 28675 - 32771][32771 - 36867 ]

 * [    hole    ][regular1 split][   prealloc ][   prealloc1  ][prealloc1 written]
@@ -91,19 +91,12 @@ static void setup_file_extents(struct btrfs_root *root, u32 sectorsize) 
	u64 disk_bytenr = SZ_1M;

	u64 offset = 0;



	/* First we want a hole */

	insert_extent(root, offset, 5, 5, 0, 0, 0, BTRFS_FILE_EXTENT_REG, 0,

		      slot);

	slot++;

	offset += 5;



	/*

	 * Now we want an inline extent, I don't think this is possible but hey

	 * why not?  Also keep in mind if we have an inline extent it counts as

	 * the whole first page.  If we were to expand it we would have to cow

	 * and we wouldn't have an inline extent anymore.

	 * Tree-checker has strict limits on inline extents that they can only

	 * exist at file offset 0, thus we can only have one inline file extent

	 * at most.

	 */

	insert_extent(root, offset, 1, 1, 0, 0, 0, BTRFS_FILE_EXTENT_INLINE, 0,

	insert_extent(root, offset, 6, 6, 0, 0, 0, BTRFS_FILE_EXTENT_INLINE, 0,

		      slot);

	slot++;

	offset = sectorsize;
@@ -282,37 +275,25 @@ static noinline int test_btrfs_get_extent(u32 sectorsize, u32 nodesize) 
		test_err("got an error when we shouldn't have");

		goto out;

	}

	if (em->block_start != EXTENT_MAP_HOLE) {

		test_err("expected a hole, got %llu", em->block_start);

		goto out;

	}

	if (em->start != 0 || em->len != 5) {

		test_err(

		"unexpected extent wanted start 0 len 5, got start %llu len %llu",

			em->start, em->len);

		goto out;

	}

	if (em->flags != 0) {

		test_err("unexpected flags set, want 0 have %lu", em->flags);

		goto out;

	}

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

	free_extent_map(em);



	em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize);

	if (IS_ERR(em)) {

		test_err("got an error when we shouldn't have");

		goto out;

	}

	if (em->block_start != EXTENT_MAP_INLINE) {

		test_err("expected an inline, got %llu", em->block_start);

		goto out;

	}



	if (em->start != offset || em->len != (sectorsize - 5)) {

	/*

	 * For inline extent, we always round up the em to sectorsize, as

	 * they are either:

	 *

	 * a) a hidden hole

	 *    The range will be zeroed at inline extent read time.

	 *

	 * b) a file extent with unaligned bytenr

	 *    Tree checker will reject it.

	 */

	if (em->start != 0 || em->len != sectorsize) {

		test_err(

	"unexpected extent wanted start %llu len 1, got start %llu len %llu",

			offset, em->start, em->len);

	"unexpected extent wanted start 0 len %u, got start %llu len %llu",

			sectorsize, em->start, em->len);

		goto out;

	}

	if (em->flags != 0) {