btrfs: add __pure attribute to functions

The attribute is more relaxed than const and the functions could
dereference pointers, as long as the observable state is not changed. We
do have such functions, based on -Wsuggest-attribute=pure .

The visible effects of this patch are negligible, there are differences
in the assembly but hard to summarize.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index b97ae1b03417975e7ef3d7145bf7a581c2c04c22..1d32a07bb2d1fb7eee72fe3cd27d7dbdf155b6f3 100644 (file)
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -53,14 +53,12 @@ struct btrfs_workqueue {
        struct __btrfs_workqueue *high;
 };
 
-struct btrfs_fs_info *
-btrfs_workqueue_owner(const struct __btrfs_workqueue *wq)
+struct btrfs_fs_info * __pure btrfs_workqueue_owner(const struct __btrfs_workqueue *wq)
 {
        return wq->fs_info;
 }
 
-struct btrfs_fs_info *
-btrfs_work_owner(const struct btrfs_work *work)
+struct btrfs_fs_info * __pure btrfs_work_owner(const struct btrfs_work *work)
 {
        return work->wq->fs_info;
 }

diff --git a/fs/btrfs/async-thread.h b/fs/btrfs/async-thread.h
index c5bf2b117c05db588eb8ea0b499d4a1adaa92b65..a4434301d84dd598b787d22308633ac1e15fe504 100644 (file)
--- a/fs/btrfs/async-thread.h
+++ b/fs/btrfs/async-thread.h
@@ -41,8 +41,8 @@ void btrfs_queue_work(struct btrfs_workqueue *wq,
 void btrfs_destroy_workqueue(struct btrfs_workqueue *wq);
 void btrfs_workqueue_set_max(struct btrfs_workqueue *wq, int max);
 void btrfs_set_work_high_priority(struct btrfs_work *work);
-struct btrfs_fs_info *btrfs_work_owner(const struct btrfs_work *work);
-struct btrfs_fs_info *btrfs_workqueue_owner(const struct __btrfs_workqueue *wq);
+struct btrfs_fs_info * __pure btrfs_work_owner(const struct btrfs_work *work);
+struct btrfs_fs_info * __pure btrfs_workqueue_owner(const struct __btrfs_workqueue *wq);
 bool btrfs_workqueue_normal_congested(const struct btrfs_workqueue *wq);
 
 #endif

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index f2f9cf1149a4cb00e54a82c54916a58c67c6b131..3a4d8e27e56588113d26922bcd5c6af799030765 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1538,7 +1538,7 @@ static int comp_keys(const struct btrfs_disk_key *disk,
 /*
  * same as comp_keys only with two btrfs_key's
  */
-int btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2)
+int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2)
 {
        if (k1->objectid > k2->objectid)
                return 1;

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8d7ac1cd49b4638e692822a390ec3f5100f2c1c0..d486703009faf47fe6bb7999d9c862d0cd9c6cf4 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2508,7 +2508,7 @@ void btrfs_wait_for_snapshot_creation(struct btrfs_root *root);
 /* ctree.c */
 int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
                     int level, int *slot);
-int btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
+int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
 int btrfs_previous_item(struct btrfs_root *root,
                        struct btrfs_path *path, u64 min_objectid,
                        int type);
@@ -2907,7 +2907,7 @@ long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 int btrfs_ioctl_get_supported_features(void __user *arg);
 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode);
-int btrfs_is_empty_uuid(u8 *uuid);
+int __pure btrfs_is_empty_uuid(u8 *uuid);
 int btrfs_defrag_file(struct inode *inode, struct file *file,
                      struct btrfs_ioctl_defrag_range_args *range,
                      u64 newer_than, unsigned long max_pages);

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 48890826b5e666d0d358495ff84bf72c9e1a55c2..f639dde2a679036d6d150264158d46986b6981ec 100644 (file)
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -986,7 +986,7 @@ static int btrfs_dev_replace_kthread(void *data)
        return 0;
 }
 
-int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
+int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
 {
        if (!dev_replace->is_valid)
                return 0;

diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h
index 78c5d8f1adda3301b5178420e3ca770a0d55d597..60b70dacc299be9c50748cef1c28e498c33a5ce6 100644 (file)
--- a/fs/btrfs/dev-replace.h
+++ b/fs/btrfs/dev-replace.h
@@ -17,6 +17,6 @@ void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info);
 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info);
-int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace);
+int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace);
 
 #endif

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 589b95eb2b80ac0e3e025d5c9053977e6d54ab8c..d7a1bd74bb71c4cf252250e317c6af3ccb5a529e 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -541,7 +541,7 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
        return 0;
 }
 
-int btrfs_is_empty_uuid(u8 *uuid)
+int __pure btrfs_is_empty_uuid(u8 *uuid)
 {
        int i;
 

diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index e8a4b0ebe97f14b6f116a618cd65d799acacc422..7539696b4cbabd82318ed34a70905b92c3882fa3 100644 (file)
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -10,7 +10,7 @@
 #include "transaction.h"
 #include "block-group.h"
 
-u64 btrfs_space_info_used(struct btrfs_space_info *s_info,
+u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,
                          bool may_use_included)
 {
        ASSERT(s_info);

diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h
index 8867e84aa33dab3ea7355d0baac70461c606c9bd..2d8c811a9792fe294223c6d5c4770d91069caacb 100644 (file)
--- a/fs/btrfs/space-info.h
+++ b/fs/btrfs/space-info.h
@@ -116,7 +116,7 @@ void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
                             struct btrfs_space_info **space_info);
 struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
                                               u64 flags);
-u64 btrfs_space_info_used(struct btrfs_space_info *s_info,
+u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,
                          bool may_use_included);
 void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
 void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,