From: Filipe Manana <fdmanana@xxxxxxxx> commit 3510e684b8f6a569c2f8b86870da116e2ffeec2d upstream. After the migration to use fs context for processing mount options we had a slight change in the semantics for remounting a filesystem that was mounted with compress-force. Before we could clear compress-force by passing only "-o compress[=algo]" during a remount, but after that change that does not work anymore, force-compress is still present and one needs to pass "-o compress-force=no,compress[=algo]" to the mount command. Example, when running on a kernel 6.8+: $ mount -o compress-force=zlib:9 /dev/sdi /mnt/sdi $ mount | grep sdi /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress-force=zlib:9,discard=async,space_cache=v2,subvolid=5,subvol=/) $ mount -o remount,compress=zlib:5 /mnt/sdi $ mount | grep sdi /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress-force=zlib:5,discard=async,space_cache=v2,subvolid=5,subvol=/) On a 6.7 kernel (or older): $ mount -o compress-force=zlib:9 /dev/sdi /mnt/sdi $ mount | grep sdi /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress-force=zlib:9,discard=async,space_cache=v2,subvolid=5,subvol=/) $ mount -o remount,compress=zlib:5 /mnt/sdi $ mount | grep sdi /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress=zlib:5,discard=async,space_cache=v2,subvolid=5,subvol=/) So update btrfs_parse_param() to clear "compress-force" when "compress" is given, providing the same semantics as kernel 6.7 and older. Reported-by: Roman Mamedov <rm@xxxxxxxxxxx> Link: https://lore.kernel.org/linux-btrfs/20241014182416.13d0f8b0@nvm/ CC: stable@xxxxxxxxxxxxxxx # 6.8+ Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/super.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 98fa0f382480..3f8673f97432 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -340,6 +340,15 @@ static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param) fallthrough; case Opt_compress: case Opt_compress_type: + /* + * Provide the same semantics as older kernels that don't use fs + * context, specifying the "compress" option clears + * "force-compress" without the need to pass + * "compress-force=[no|none]" before specifying "compress". + */ + if (opt != Opt_compress_force && opt != Opt_compress_force_type) + btrfs_clear_opt(ctx->mount_opt, FORCE_COMPRESS); + if (opt == Opt_compress || opt == Opt_compress_force) { ctx->compress_type = BTRFS_COMPRESS_ZLIB; ctx->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL; -- 2.47.0 Patches currently in stable-queue which might be from fdmanana@xxxxxxxx are queue-6.11/btrfs-clear-force-compress-on-remount-when-compress-mount-option-is-given.patch queue-6.11/btrfs-fix-read-corruption-due-to-race-with-extent-map-merging.patch
