From 00deaf04df35536d192544ea57b6da9a88519422 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Mon, 4 Dec 2023 16:20:29 +0000 Subject: [PATCH] btrfs: log messages at unpin_extent_range() during unexpected cases At unpin_extent_range() we trigger a WARN_ON() when we don't find an extent map or we find one with a start offset not matching the start offset of the target range. This however isn't very useful for debugging because: 1) We don't know which condition was triggered, as they are both in the same WARN_ON() call; 2) We don't know which inode was affected, from which root, for which range, what's the start offset of the extent map, and so on. So trigger a separate warning for each case and log a message for each case providing information about the inode, its root, the target range, the generation and the start offset of the extent map we found. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent_map.c | 22 ++++++++++++++++------ fs/btrfs/extent_map.h | 2 +- fs/btrfs/inode.c | 2 +- 3 files changed, 18 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index a3d69c943eec..48230a1179b0 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -280,7 +280,7 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em) /* * Unpin an extent from the cache. * - * @tree: tree to unpin the extent in + * @inode: the inode from which we are unpinning an extent range * @start: logical offset in the file * @len: length of the extent * @gen: generation that this extent has been modified in @@ -289,9 +289,10 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em) * to the generation that actually added the file item to the inode so we know * we need to sync this extent when we call fsync(). */ -int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, - u64 gen) +int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen) { + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct extent_map_tree *tree = &inode->extent_tree; int ret = 0; struct extent_map *em; bool prealloc = false; @@ -299,10 +300,19 @@ int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, write_lock(&tree->lock); em = lookup_extent_mapping(tree, start, len); - WARN_ON(!em || em->start != start); - - if (!em) + if (WARN_ON(!em)) { + btrfs_warn(fs_info, +"no extent map found for inode %llu (root %lld) when unpinning extent range [%llu, %llu), generation %llu", + btrfs_ino(inode), btrfs_root_id(inode->root), + start, len, gen); goto out; + } + + if (WARN_ON(em->start != start)) + btrfs_warn(fs_info, +"found extent map for inode %llu (root %lld) with unexpected start offset %llu when unpinning extent range [%llu, %llu), generation %llu", + btrfs_ino(inode), btrfs_root_id(inode->root), + em->start, start, len, gen); em->generation = gen; clear_bit(EXTENT_FLAG_PINNED, &em->flags); diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h index 5663137471fe..cd1a9115908d 100644 --- a/fs/btrfs/extent_map.h +++ b/fs/btrfs/extent_map.h @@ -82,7 +82,7 @@ struct extent_map *alloc_extent_map(void); void free_extent_map(struct extent_map *em); int __init extent_map_init(void); void __cold extent_map_exit(void); -int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen); +int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen); void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em); struct extent_map *search_extent_mapping(struct extent_map_tree *tree, u64 start, u64 len); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 38adab92a015..88614bb87b95 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3127,7 +3127,7 @@ int btrfs_finish_one_ordered(struct btrfs_ordered_extent *ordered_extent) ordered_extent->disk_num_bytes); } } - unpin_extent_cache(&inode->extent_tree, ordered_extent->file_offset, + unpin_extent_cache(inode, ordered_extent->file_offset, ordered_extent->num_bytes, trans->transid); if (ret < 0) { btrfs_abort_transaction(trans, ret);