[PATCH 1/4] btrfs: export btrfs_match_compress_type(), move it to compression.h

Export btrfs_match_compress_type() from being a static and locally used
function in super.c and move it to compression.c, exporting it in
compression.h. This allows it to be used in the next patches as validation
for compression algorithm names.

Assisted-by: Gemini:3.1-pro antigravity-cli-1.1.5
Signed-off-by: koraynilay <[email protected]>
---
 fs/btrfs/compression.c | 17 +++++++++++++++++
 fs/btrfs/compression.h |  1 +
 fs/btrfs/super.c       |  8 --------
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index ffb6b52863a7..58138f300b58 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1660,3 +1660,20 @@ int btrfs_compress_str2level(unsigned int type, const char *str, int *level_ret)
 	*level_ret = btrfs_compress_set_level(type, level);
 	return 0;
 }
+
+/**
+ * btrfs_match_compress_type - Check if the string matches the compression type
+ * @string:         The string to check
+ * @type:           The compression type string (name) to match against (e.g. "zstd")
+ * @may_have_level: If true, the string may have a level suffix (e.g., ":1")
+ *
+ * Return: %true if the string matches the type and, if %may_have_level is %true,
+ * has a level suffix, %false otherwise.
+ */
+bool btrfs_match_compress_type(const char *string, const char *type, bool may_have_level)
+{
+	const int len = strlen(type);
+
+	return (strncmp(string, type, len) == 0) &&
+		((may_have_level && string[len] == ':') || string[len] == '\0');
+}
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 1022dc53ec51..e67ba47b4cdc 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -97,6 +97,7 @@ void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered,
 void btrfs_submit_compressed_read(struct btrfs_bio *bbio);
 
 int btrfs_compress_str2level(unsigned int type, const char *str, int *level_ret);
+bool btrfs_match_compress_type(const char *string, const char *type, bool may_have_level);
 
 struct folio *btrfs_alloc_compr_folio(struct btrfs_fs_info *fs_info, gfp_t gfp);
 void btrfs_free_compr_folio(struct folio *folio);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f4e34898d581..7a21085c33c5 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -264,14 +264,6 @@ static const struct fs_parameter_spec btrfs_fs_parameters[] = {
 	{}
 };
 
-static bool btrfs_match_compress_type(const char *string, const char *type, bool may_have_level)
-{
-	const 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,
 				const struct fs_parameter *param, int opt)
 {
-- 
2.55.0