btrfs: factor out compression mount options parsing

There are many options making the parsing a bit lengthy.  Factor the
compress options out into a helper function.  The next patch is going to
harden this function.

Signed-off-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index a0c65adce1abd23c02cdb46fa95920bfa14dd091..408ce5418c18992726f2b656332bb5b04cd84cdb 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -267,6 +267,56 @@ static inline blk_mode_t btrfs_open_mode(struct fs_context *fc)
        return sb_open_mode(fc->sb_flags) & ~BLK_OPEN_RESTRICT_WRITES;
 }
 
+static int btrfs_parse_compress(struct btrfs_fs_context *ctx,
+                               const struct fs_parameter *param, int opt)
+{
+       /*
+        * 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;
+               btrfs_set_opt(ctx->mount_opt, COMPRESS);
+               btrfs_clear_opt(ctx->mount_opt, NODATACOW);
+               btrfs_clear_opt(ctx->mount_opt, NODATASUM);
+       } else if (strncmp(param->string, "zlib", 4) == 0) {
+               ctx->compress_type = BTRFS_COMPRESS_ZLIB;
+               ctx->compress_level = btrfs_compress_str2level(BTRFS_COMPRESS_ZLIB,
+                                                              param->string + 4);
+               btrfs_set_opt(ctx->mount_opt, COMPRESS);
+               btrfs_clear_opt(ctx->mount_opt, NODATACOW);
+               btrfs_clear_opt(ctx->mount_opt, NODATASUM);
+       } else if (strncmp(param->string, "lzo", 3) == 0) {
+               ctx->compress_type = BTRFS_COMPRESS_LZO;
+               ctx->compress_level = 0;
+               btrfs_set_opt(ctx->mount_opt, COMPRESS);
+               btrfs_clear_opt(ctx->mount_opt, NODATACOW);
+               btrfs_clear_opt(ctx->mount_opt, NODATASUM);
+       } else if (strncmp(param->string, "zstd", 4) == 0) {
+               ctx->compress_type = BTRFS_COMPRESS_ZSTD;
+               ctx->compress_level = btrfs_compress_str2level(BTRFS_COMPRESS_ZSTD,
+                                                              param->string + 4);
+               btrfs_set_opt(ctx->mount_opt, COMPRESS);
+               btrfs_clear_opt(ctx->mount_opt, NODATACOW);
+               btrfs_clear_opt(ctx->mount_opt, NODATASUM);
+       } else if (strncmp(param->string, "no", 2) == 0) {
+               ctx->compress_level = 0;
+               ctx->compress_type = 0;
+               btrfs_clear_opt(ctx->mount_opt, COMPRESS);
+               btrfs_clear_opt(ctx->mount_opt, FORCE_COMPRESS);
+       } else {
+               btrfs_err(NULL, "unrecognized compression value %s", param->string);
+               return -EINVAL;
+       }
+       return 0;
+}
+
 static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
        struct btrfs_fs_context *ctx = fc->fs_private;
@@ -336,53 +386,8 @@ 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;
-                       btrfs_set_opt(ctx->mount_opt, COMPRESS);
-                       btrfs_clear_opt(ctx->mount_opt, NODATACOW);
-                       btrfs_clear_opt(ctx->mount_opt, NODATASUM);
-               } else if (strncmp(param->string, "zlib", 4) == 0) {
-                       ctx->compress_type = BTRFS_COMPRESS_ZLIB;
-                       ctx->compress_level =
-                               btrfs_compress_str2level(BTRFS_COMPRESS_ZLIB,
-                                                        param->string + 4);
-                       btrfs_set_opt(ctx->mount_opt, COMPRESS);
-                       btrfs_clear_opt(ctx->mount_opt, NODATACOW);
-                       btrfs_clear_opt(ctx->mount_opt, NODATASUM);
-               } else if (strncmp(param->string, "lzo", 3) == 0) {
-                       ctx->compress_type = BTRFS_COMPRESS_LZO;
-                       ctx->compress_level = 0;
-                       btrfs_set_opt(ctx->mount_opt, COMPRESS);
-                       btrfs_clear_opt(ctx->mount_opt, NODATACOW);
-                       btrfs_clear_opt(ctx->mount_opt, NODATASUM);
-               } else if (strncmp(param->string, "zstd", 4) == 0) {
-                       ctx->compress_type = BTRFS_COMPRESS_ZSTD;
-                       ctx->compress_level =
-                               btrfs_compress_str2level(BTRFS_COMPRESS_ZSTD,
-                                                        param->string + 4);
-                       btrfs_set_opt(ctx->mount_opt, COMPRESS);
-                       btrfs_clear_opt(ctx->mount_opt, NODATACOW);
-                       btrfs_clear_opt(ctx->mount_opt, NODATASUM);
-               } else if (strncmp(param->string, "no", 2) == 0) {
-                       ctx->compress_level = 0;
-                       ctx->compress_type = 0;
-                       btrfs_clear_opt(ctx->mount_opt, COMPRESS);
-                       btrfs_clear_opt(ctx->mount_opt, FORCE_COMPRESS);
-               } else {
-                       btrfs_err(NULL, "unrecognized compression value %s",
-                                 param->string);
+               if (btrfs_parse_compress(ctx, param, opt))
                        return -EINVAL;
-               }
                break;
        case Opt_ssd:
                if (result.negated) {