[PATCH 5/5] btrfs-progs: lowmem check: Fix false alert on missing chunk or dev extent

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

When checking chunk or dev extent, lowmem mode uses chunk length as dev
extent length, and if they mismatch, report missing chunk or dev extent
like:
------
ERROR: chunk[256 4324327424) stripe 0 did not find the related dev extent
ERROR: chunk[256 4324327424) stripe 1 did not find the related dev extent
ERROR: chunk[256 4324327424) stripe 2 did not find the related dev extent
------

However, only for Single/DUP/RAID1 profiles chunk length is the same as
dev extent length.
For other profiles, this will cause tons of false alert.

Fix it by using correct stripe length when checking chunk and dev extent
items.

Reported-by: Kai Krakow <hurikhan77@gmail.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
Test cases for this bug will follow as another patchset, since we need
some infrastructure update to support multi-device mkfs/check/mount.
---
 cmds-check.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/cmds-check.c b/cmds-check.c
index 58b73608..eb3eb9e9 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -10872,7 +10872,12 @@ static int check_dev_extent_item(struct btrfs_fs_info *fs_info,
 
 	l = path.nodes[0];
 	chunk = btrfs_item_ptr(l, path.slots[0], struct btrfs_chunk);
-	if (btrfs_chunk_length(l, chunk) != length)
+	ret = btrfs_check_chunk_valid(chunk_root, l, chunk, path.slots[0],
+				      chunk_key.offset);
+	if (ret < 0)
+		goto out;
+
+	if (btrfs_stripe_length(fs_info, l, chunk) != length)
 		goto out;
 
 	num_stripes = btrfs_chunk_num_stripes(l, chunk);
@@ -11112,6 +11117,7 @@ static int check_chunk_item(struct btrfs_fs_info *fs_info,
 	struct btrfs_dev_extent *ptr;
 	u64 length;
 	u64 chunk_end;
+	u64 stripe_len;
 	u64 type;
 	int num_stripes;
 	u64 offset;
@@ -11161,6 +11167,7 @@ static int check_chunk_item(struct btrfs_fs_info *fs_info,
 	}
 
 	num_stripes = btrfs_chunk_num_stripes(eb, chunk);
+	stripe_len = btrfs_stripe_length(fs_info, eb, chunk);
 	for (i = 0; i < num_stripes; i++) {
 		btrfs_release_path(&path);
 		btrfs_init_path(&path);
@@ -11180,7 +11187,7 @@ static int check_chunk_item(struct btrfs_fs_info *fs_info,
 		offset = btrfs_dev_extent_chunk_offset(leaf, ptr);
 		if (objectid != chunk_key.objectid ||
 		    offset != chunk_key.offset ||
-		    btrfs_dev_extent_length(leaf, ptr) != length)
+		    btrfs_dev_extent_length(leaf, ptr) != stripe_len)
 			goto not_match_dev;
 		continue;
 not_match_dev:
-- 
2.12.2