From 23019d3e6617a8ec99a8d2f5947aa3dd8a74a1b8 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 25 Feb 2025 14:30:44 +1030 Subject: [PATCH] btrfs: properly limit inline data extent according to block size Btrfs utilizes inline data extent for the following cases: - Regular small files - Symlinks And "btrfs check" detects any file extents that are too large as an error. It's not a problem for 4K block size, but for the incoming smaller block sizes (2K), it can cause problems due to bad limits: - Non-compressed inline data extents We do not allow a non-compressed inline data extent to be as large as block size. - Symlinks Currently the only real limit on symlinks are 4K, which can be larger than 2K block size. These will result btrfs-check to report too large file extents. Fix it by adding proper size checks for the above cases. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/inode.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 012ac47351fc..0740a42d393b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -570,6 +570,10 @@ static bool can_cow_file_range_inline(struct btrfs_inode *inode, if (size > fs_info->sectorsize) return false; + /* We do not allow a non-compressed extent to be as large as block size. */ + if (data_len >= fs_info->sectorsize) + return false; + /* We cannot exceed the maximum inline data size. */ if (data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info)) return false; @@ -8670,7 +8674,12 @@ static int btrfs_symlink(struct mnt_idmap *idmap, struct inode *dir, struct extent_buffer *leaf; name_len = strlen(symname); - if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info)) + /* + * Symlinks utilize uncompressed inline extent data, which should not + * reach block size. + */ + if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) || + name_len >= fs_info->sectorsize) return -ENAMETOOLONG; inode = new_inode(dir->i_sb); -- 2.50.1