There are some cases where decompressed sectors can have padding zeros.
In kernel code, we have lines to address such situation:
/* * btrfs_getblock is doing a zero on the tail of the page too, * but this will cover anything missing from the decompressed * data. */ if (bytes < destlen) memset(kaddr+bytes, 0, destlen-bytes); kunmap_local(kaddr);
But not in U-boot code, thus we have some reports of U-boot failed to read compressed files in btrfs.
Fix it by doing the same thing of the kernel, for both inline and regular compressed extents.
Reported-by: Matwey Kornilov matwey.kornilov@gmail.com Link: https://bugzilla.suse.com/show_bug.cgi?id=1183717 Fixes: a26a6bedafcf ("fs: btrfs: Introduce btrfs_read_extent_inline() and btrfs_read_extent_reg()") Signed-off-by: Qu Wenruo wqu@suse.com --- Changelog: v2: - Fix the bug for regular and inline compressed extents --- fs/btrfs/inode.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 019d532a1a4b..2c2379303d74 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -390,10 +390,16 @@ int btrfs_read_extent_inline(struct btrfs_path *path, csize); ret = btrfs_decompress(btrfs_file_extent_compression(leaf, fi), cbuf, csize, dbuf, dsize); - if (ret < 0 || ret != dsize) { + if (ret == (u32)-1) { ret = -EIO; goto out; } + /* + * The compressed part ends before sector boundary, the remaining needs + * to be zeroed out. + */ + if (ret < dsize) + memset(dbuf + ret, 0, dsize - ret); memcpy(dest, dbuf, dsize); ret = dsize; out: @@ -494,10 +500,16 @@ int btrfs_read_extent_reg(struct btrfs_path *path,
ret = btrfs_decompress(btrfs_file_extent_compression(leaf, fi), cbuf, csize, dbuf, dsize); - if (ret != dsize) { + if (ret == (u32)-1) { ret = -EIO; goto out; } + /* + * The compressed part ends before sector boundary, the remaining needs + * to be zeroed out. + */ + if (ret < dsize) + memset(dbuf + ret, 0, dsize - ret); /* Then copy the needed part */ memcpy(dest, dbuf + btrfs_file_extent_offset(leaf, fi), len); ret = len;