btrfs: dev-replace: move replace members out of fs_info

The replace_wait and bio_counter were mistakenly added to fs_info in
commit c404e0dc2c843b154f ("Btrfs: fix use-after-free in the finishing
procedure of the device replace"), but they logically belong to
fs_info::dev_replace. Besides, bio_counter is a very generic name and is
confusing in bare fs_info context.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

3 files changed, 16 insertions, 15 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index daa273c7e150..e8244c0b0597 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -365,6 +365,9 @@ struct btrfs_dev_replace {
         wait_queue_head_t read_lock_wq;
 
         struct btrfs_scrub_progress scrub_progress;
+
+        struct percpu_counter bio_counter;
+        wait_queue_head_t replace_wait;
 };
 
 /* For raid type sysfs entries */
@@ -1087,9 +1090,6 @@ struct btrfs_fs_info {
         /* device replace state */
         struct btrfs_dev_replace dev_replace;
 
-        struct percpu_counter bio_counter;
-        wait_queue_head_t replace_wait;
-
         struct semaphore uuid_tree_rescan_sem;
 
         /* Used to reclaim the metadata space in the background. */
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index c7f2d6b91a6f..d1ea76bccaaf 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -545,8 +545,8 @@ int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info,
 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
 {
         set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
-        wait_event(fs_info->replace_wait, !percpu_counter_sum(
-                   &fs_info->bio_counter));
+        wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum(
+                   &fs_info->dev_replace.bio_counter));
 }
 
 /*
@@ -555,7 +555,7 @@ static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info)
 {
         clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
-        wake_up(&fs_info->replace_wait);
+        wake_up(&fs_info->dev_replace.replace_wait);
 }
 
 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
@@ -997,25 +997,25 @@ void btrfs_dev_replace_set_lock_blocking(
 
 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
 {
-        percpu_counter_inc(&fs_info->bio_counter);
+        percpu_counter_inc(&fs_info->dev_replace.bio_counter);
 }
 
 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount)
 {
-        percpu_counter_sub(&fs_info->bio_counter, amount);
-        cond_wake_up_nomb(&fs_info->replace_wait);
+        percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount);
+        cond_wake_up_nomb(&fs_info->dev_replace.replace_wait);
 }
 
 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
 {
         while (1) {
-                percpu_counter_inc(&fs_info->bio_counter);
+                percpu_counter_inc(&fs_info->dev_replace.bio_counter);
                 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING,
                                      &fs_info->fs_state)))
                         break;
 
                 btrfs_bio_counter_dec(fs_info);
-                wait_event(fs_info->replace_wait,
+                wait_event(fs_info->dev_replace.replace_wait,
                            !test_bit(BTRFS_FS_STATE_DEV_REPLACING,
                                      &fs_info->fs_state));
         }
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 79903243877b..27f6a3348f94 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2156,7 +2156,7 @@ static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
         rwlock_init(&fs_info->dev_replace.lock);
         atomic_set(&fs_info->dev_replace.blocking_readers, 0);
-        init_waitqueue_head(&fs_info->replace_wait);
+        init_waitqueue_head(&fs_info->dev_replace.replace_wait);
         init_waitqueue_head(&fs_info->dev_replace.read_lock_wq);
 }
 
@@ -2646,7 +2646,8 @@ int open_ctree(struct super_block *sb,
                 goto fail_dirty_metadata_bytes;
         }
 
-        ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
+        ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
+                        GFP_KERNEL);
         if (ret) {
                 err = ret;
                 goto fail_delalloc_bytes;
@@ -3307,7 +3308,7 @@ fail_iput:
 
         iput(fs_info->btree_inode);
 fail_bio_counter:
-        percpu_counter_destroy(&fs_info->bio_counter);
+        percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
 fail_delalloc_bytes:
         percpu_counter_destroy(&fs_info->delalloc_bytes);
 fail_dirty_metadata_bytes:
@@ -4016,7 +4017,7 @@ void close_ctree(struct btrfs_fs_info *fs_info)
 
         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
         percpu_counter_destroy(&fs_info->delalloc_bytes);
-        percpu_counter_destroy(&fs_info->bio_counter);
+        percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
         cleanup_srcu_struct(&fs_info->subvol_srcu);
 
         btrfs_free_stripe_hash_table(fs_info);