btrfs: use better definition of number of compression type

The compression type upper limit constant is the same as the last value
and this is confusing.  In order to keep coding style consistent, use
BTRFS_NR_COMPRESS_TYPES as the total number that follows the idom of
'NR' being one more than the last value.

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
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 d70c464..93deaf0 100644 (file)
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -39,6 +39,8 @@ const char* btrfs_compress_type2str(enum btrfs_compression_type type)
        case BTRFS_COMPRESS_ZSTD:
        case BTRFS_COMPRESS_NONE:
                return btrfs_compress_types[type];
+       default:
+               break;
        }
 
        return NULL;

diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index dd39227..52dce11 100644 (file)
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -105,7 +105,7 @@ enum btrfs_compression_type {
        BTRFS_COMPRESS_ZLIB  = 1,
        BTRFS_COMPRESS_LZO   = 2,
        BTRFS_COMPRESS_ZSTD  = 3,
-       BTRFS_COMPRESS_TYPES = 3,
+       BTRFS_NR_COMPRESS_TYPES = 4,
 };
 
 struct workspace_manager {
@@ -163,7 +163,7 @@ struct btrfs_compress_op {
 };
 
 /* The heuristic workspaces are managed via the 0th workspace manager */
-#define BTRFS_NR_WORKSPACE_MANAGERS    (BTRFS_COMPRESS_TYPES + 1)
+#define BTRFS_NR_WORKSPACE_MANAGERS    BTRFS_NR_COMPRESS_TYPES
 
 extern const struct btrfs_compress_op btrfs_heuristic_compress;
 extern const struct btrfs_compress_op btrfs_zlib_compress;

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index d7a1bd7..5892fa9 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1409,7 +1409,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
                return -EINVAL;
 
        if (do_compress) {
-               if (range->compress_type > BTRFS_COMPRESS_TYPES)
+               if (range->compress_type >= BTRFS_NR_COMPRESS_TYPES)
                        return -EINVAL;
                if (range->compress_type)
                        compress_type = range->compress_type;

diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index 9699c91..f475161 100644 (file)
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -233,11 +233,11 @@ static int check_extent_data_item(struct extent_buffer *leaf,
         * Support for new compression/encryption must introduce incompat flag,
         * and must be caught in open_ctree().
         */
-       if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) {
+       if (btrfs_file_extent_compression(leaf, fi) >= BTRFS_NR_COMPRESS_TYPES) {
                file_extent_err(leaf, slot,
        "invalid compression for file extent, have %u expect range [0, %u]",
                        btrfs_file_extent_compression(leaf, fi),
-                       BTRFS_COMPRESS_TYPES);
+                       BTRFS_NR_COMPRESS_TYPES - 1);
                return -EUCLEAN;
        }
        if (btrfs_file_extent_encryption(leaf, fi)) {