btrfs: zoned: add asserts on splitting extent_map

We call split_zoned_em() on an extent_map on submitting a bio for it. Thus,
we can assume the extent_map is PINNED, not LOGGING, and in the modified
list. Add ASSERT()s to ensure the extent_maps after the split also has the
proper flags set and are in the modified list.

Suggested-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d8a1e58..09bd7c1 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2303,7 +2303,6 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
        struct extent_map *split_mid = NULL;
        struct extent_map *split_post = NULL;
        int ret = 0;
-       int modified;
        unsigned long flags;
 
        /* Sanity check */
@@ -2333,11 +2332,12 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
        ASSERT(em->len == len);
        ASSERT(!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags));
        ASSERT(em->block_start < EXTENT_MAP_LAST_BYTE);
+       ASSERT(test_bit(EXTENT_FLAG_PINNED, &em->flags));
+       ASSERT(!test_bit(EXTENT_FLAG_LOGGING, &em->flags));
+       ASSERT(!list_empty(&em->list));
 
        flags = em->flags;
        clear_bit(EXTENT_FLAG_PINNED, &em->flags);
-       clear_bit(EXTENT_FLAG_LOGGING, &flags);
-       modified = !list_empty(&em->list);
 
        /* First, replace the em with a new extent_map starting from * em->start */
        split_pre->start = em->start;
@@ -2351,7 +2351,7 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
        split_pre->compress_type = em->compress_type;
        split_pre->generation = em->generation;
 
-       replace_extent_mapping(em_tree, em, split_pre, modified);
+       replace_extent_mapping(em_tree, em, split_pre, 1);
 
        /*
         * Now we only have an extent_map at:
@@ -2371,7 +2371,7 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
                split_mid->flags = flags;
                split_mid->compress_type = em->compress_type;
                split_mid->generation = em->generation;
-               add_extent_mapping(em_tree, split_mid, modified);
+               add_extent_mapping(em_tree, split_mid, 1);
        }
 
        if (post) {
@@ -2385,7 +2385,7 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
                split_post->flags = flags;
                split_post->compress_type = em->compress_type;
                split_post->generation = em->generation;
-               add_extent_mapping(em_tree, split_post, modified);
+               add_extent_mapping(em_tree, split_post, 1);
        }
 
        /* Once for us */