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 d70c464074209e42cc4db862385c048c1fea4c01..93deaf0cc2b84d164f9e9797f67c3f028e4f25e6 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 dd392278ab3f2324f0099f2afb03480b03323af3..52dce1176f897333a161880df0a60f788762764d 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 d7a1bd74bb71c4cf252250e317c6af3ccb5a529e..5892fa9398c36857373e93c3b835224aaa13659d 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 9699c91c958eabf64d7b34e405d2038729e546e4..f4751615a189d5755fa8d3f91321830686dd446d 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)) {