On Thu, Jun 12, 2025 at 03:29:21PM +0200, Daniel Vacek wrote:

On Mon, 2 Jun 2025 at 19:29, David Sterba [off-list ref] wrote:

quoted

On Mon, Jun 02, 2025 at 05:53:19PM +0200, Daniel Vacek wrote:

quoted

Btrfs happily but incorrectly accepts the `-o compress=zlib+foo` and similar
options with any random suffix.

Fix that by explicitly checking the end of the strings.

Signed-off-by: Daniel Vacek <redacted>
---
v3 changes: Split into two patches to ease backporting,
            no functional changes.

 fs/btrfs/super.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 6291ab45ab2a5..4510c5f7a785e 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c

@@ -270,9 +270,20 @@ static inline blk_mode_t btrfs_open_mode(struct fs_context *fc)
      return sb_open_mode(fc->sb_flags) & ~BLK_OPEN_RESTRICT_WRITES;
 }

+static bool btrfs_match_compress_type(char *string, char *type, bool may_have_level)

const also here, string, type

quoted

+{
+     int len = strlen(type);
+
+     return strncmp(string, type, len) == 0 &&
+             ((may_have_level && string[len] == ':') ||
+                                 string[len] == '\0');
+}
+
 static int btrfs_parse_compress(struct btrfs_fs_context *ctx,
                              struct fs_parameter *param, int opt)
 {
+     char *string = param->string;

and here

Can be done at merge time. Or do you want a re-send?

No resend needed, I updated the patch in for-next. This was to let you
know so that I don't need to fix it in future patches.