btrfs: change set_level() to bound the level passed in

Currently, the only user of set_level() is zlib which sets an internal
workspace parameter. As level is now plumbed into get_workspace(), this
can be handled there rather than separately.

This repurposes set_level() to bound the level passed in so it can be
used when setting the mounts compression level and as well as verifying
the level before getting a workspace. The other benefit is this divides
the meaning of compress(0) and get_workspace(0). The former means we
want to use the default compression level of the compression type. The
latter means we can use any workspace available.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index ccd6bb2..eb8e20b 100644 (file)
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1009,8 +1009,6 @@ int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
        int ret;
 
        workspace = get_workspace(type, level);
-
-       btrfs_compress_op[type]->set_level(workspace, level);
        ret = btrfs_compress_op[type]->compress_pages(workspace, mapping,
                                                      start, pages,
                                                      out_pages,
@@ -1563,14 +1561,25 @@ out:
        return ret;
 }
 
-unsigned int btrfs_compress_str2level(const char *str)
+/*
+ * Convert the compression suffix (eg. after "zlib" starting with ":") to
+ * level, unrecognized string will set the default level
+ */
+unsigned int btrfs_compress_str2level(unsigned int type, const char *str)
 {
-       if (strncmp(str, "zlib", 4) != 0)
+       unsigned int level = 0;
+       int ret;
+
+       if (!type)
                return 0;
 
-       /* Accepted form: zlib:1 up to zlib:9 and nothing left after the number */
-       if (str[4] == ':' && '1' <= str[5] && str[5] <= '9' && str[6] == 0)
-               return str[5] - '0';
+       if (str[0] == ':') {
+               ret = kstrtouint(str + 1, 10, &level);
+               if (ret)
+                       level = 0;
+       }
+
+       level = btrfs_compress_op[type]->set_level(level);
 
-       return BTRFS_ZLIB_DEFAULT_LEVEL;
+       return level;
 }

diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 2ab8b2f..9976fe0 100644 (file)
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -97,7 +97,7 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
                                 int mirror_num, unsigned long bio_flags);
 
-unsigned btrfs_compress_str2level(const char *str);
+unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
 
 enum btrfs_compression_type {
        BTRFS_COMPRESS_NONE  = 0,
@@ -156,7 +156,12 @@ struct btrfs_compress_op {
                          unsigned long start_byte,
                          size_t srclen, size_t destlen);
 
-       void (*set_level)(struct list_head *ws, unsigned int type);
+       /*
+        * This bounds the level set by the user to be within range of a
+        * particular compression type.  It returns the level that will be used
+        * if the level is out of bounds or the default if 0 is passed in.
+        */
+       unsigned int (*set_level)(unsigned int level);
 };
 
 /* The heuristic workspaces are managed via the 0th workspace manager */

diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index f132af4..579d53a 100644 (file)
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -507,8 +507,9 @@ out:
        return ret;
 }
 
-static void lzo_set_level(struct list_head *ws, unsigned int type)
+static unsigned int lzo_set_level(unsigned int level)
 {
+       return 0;
 }
 
 const struct btrfs_compress_op btrfs_lzo_compress = {

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f9d13a3..9ac94c9 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -529,7 +529,9 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
                                if (token != Opt_compress &&
                                    token != Opt_compress_force)
                                        info->compress_level =
-                                         btrfs_compress_str2level(args[0].from);
+                                         btrfs_compress_str2level(
+                                                       BTRFS_COMPRESS_ZLIB,
+                                                       args[0].from + 4);
                                btrfs_set_opt(info->mount_opt, COMPRESS);
                                btrfs_clear_opt(info->mount_opt, NODATACOW);
                                btrfs_clear_opt(info->mount_opt, NODATASUM);

diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index fc883a1..b86b7ad 100644 (file)
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -41,7 +41,12 @@ static void zlib_cleanup_workspace_manager(void)
 
 static struct list_head *zlib_get_workspace(unsigned int level)
 {
-       return btrfs_get_workspace(&wsm, level);
+       struct list_head *ws = btrfs_get_workspace(&wsm, level);
+       struct workspace *workspace = list_entry(ws, struct workspace, list);
+
+       workspace->level = level;
+
+       return ws;
 }
 
 static void zlib_put_workspace(struct list_head *ws)
@@ -413,15 +418,12 @@ next:
        return ret;
 }
 
-static void zlib_set_level(struct list_head *ws, unsigned int type)
+static unsigned int zlib_set_level(unsigned int level)
 {
-       struct workspace *workspace = list_entry(ws, struct workspace, list);
-       unsigned int level = btrfs_compress_level(type);
-
-       if (level > 9)
-               level = 9;
+       if (!level)
+               return BTRFS_ZLIB_DEFAULT_LEVEL;
 
-       workspace->level = level > 0 ? level : 3;
+       return min_t(unsigned int, level, 9);
 }
 
 const struct btrfs_compress_op btrfs_zlib_compress = {

diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
index 4041018..43f3be7 100644 (file)
--- a/fs/btrfs/zstd.c
+++ b/fs/btrfs/zstd.c
@@ -441,8 +441,9 @@ finish:
        return ret;
 }
 
-static void zstd_set_level(struct list_head *ws, unsigned int type)
+static unsigned int zstd_set_level(unsigned int level)
 {
+       return ZSTD_BTRFS_DEFAULT_LEVEL;
 }
 
 const struct btrfs_compress_op btrfs_zstd_compress = {