btrfs: constify structs with op functions or static definitions

There are some op tables that can be easily made const, similarly the
sysfs feature and raid tables. This is motivated by PaX CONSTIFY plugin.

Signed-off-by: David Sterba <dsterba@suse.cz>

10 files changed, 13 insertions, 11 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index e9df8862012c..e7a94f8cdfd7 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -750,7 +750,7 @@ static int comp_num_workspace[BTRFS_COMPRESS_TYPES];
 static atomic_t comp_alloc_workspace[BTRFS_COMPRESS_TYPES];
 static wait_queue_head_t comp_workspace_wait[BTRFS_COMPRESS_TYPES];
 
-static struct btrfs_compress_op *btrfs_compress_op[] = {
+static const struct btrfs_compress_op * const btrfs_compress_op[] = {
         &btrfs_zlib_compress,
         &btrfs_lzo_compress,
 };
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index d181f70caae0..13a4dc0436c9 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -77,7 +77,7 @@ struct btrfs_compress_op {
                           size_t srclen, size_t destlen);
 };
 
-extern struct btrfs_compress_op btrfs_zlib_compress;
-extern struct btrfs_compress_op btrfs_lzo_compress;
+extern const struct btrfs_compress_op btrfs_zlib_compress;
+extern const struct btrfs_compress_op btrfs_lzo_compress;
 
 #endif
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ed5dcfe52f91..83671f847c7c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -54,7 +54,7 @@
 #include <asm/cpufeature.h>
 #endif
 
-static struct extent_io_ops btree_extent_io_ops;
+static const struct extent_io_ops btree_extent_io_ops;
 static void end_workqueue_fn(struct btrfs_work *work);
 static void free_fs_root(struct btrfs_root *root);
 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
@@ -4287,7 +4287,7 @@ static int btrfs_cleanup_transaction(struct btrfs_root *root)
         return 0;
 }
 
-static struct extent_io_ops btree_extent_io_ops = {
+static const struct extent_io_ops btree_extent_io_ops = {
         .readpage_end_io_hook = btree_readpage_end_io_hook,
         .readpage_io_failed_hook = btree_io_failed_hook,
         .submit_bio_hook = btree_submit_bio_hook,
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 695b0ccfb755..c668f36898d3 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -97,7 +97,7 @@ struct extent_io_tree {
         u64 dirty_bytes;
         int track_uptodate;
         spinlock_t lock;
-        struct extent_io_ops *ops;
+        const struct extent_io_ops *ops;
 };
 
 struct extent_state {
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index 617553cdb7d3..a2f051347731 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -434,7 +434,7 @@ out:
         return ret;
 }
 
-struct btrfs_compress_op btrfs_lzo_compress = {
+const struct btrfs_compress_op btrfs_lzo_compress = {
         .alloc_workspace        = lzo_alloc_workspace,
         .free_workspace         = lzo_free_workspace,
         .compress_pages         = lzo_compress_pages,
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index 129b1dd28527..dca137b04095 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -425,3 +425,5 @@ static const char *prop_compression_extract(struct inode *inode)
 
         return NULL;
 }
+
+
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 94edb0a2a026..e8a4c86d274d 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -459,7 +459,7 @@ static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
 static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13];
 static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS];
 
-static u64 supported_feature_masks[3] = {
+static const u64 supported_feature_masks[3] = {
         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 038fcf6051e0..dde9d285308e 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -35,7 +35,7 @@
 
 #define BTRFS_ROOT_TRANS_TAG 0
 
-static unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
+static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
         [TRANS_STATE_RUNNING]           = 0U,
         [TRANS_STATE_BLOCKED]           = (__TRANS_USERSPACE |
                                            __TRANS_START),
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index cd4d1315aaa9..33ed9df08a9c 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4131,7 +4131,7 @@ static int btrfs_cmp_device_info(const void *a, const void *b)
         return 0;
 }
 
-static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
+static const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
         [BTRFS_RAID_RAID10] = {
                 .sub_stripes    = 2,
                 .dev_stripes    = 1,
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index fb22fd8d8fb8..82990b8f872b 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -403,7 +403,7 @@ next:
         return ret;
 }
 
-struct btrfs_compress_op btrfs_zlib_compress = {
+const struct btrfs_compress_op btrfs_zlib_compress = {
         .alloc_workspace        = zlib_alloc_workspace,
         .free_workspace         = zlib_free_workspace,
         .compress_pages         = zlib_compress_pages,