fuse: Convert to separately allocated bdi

Allocate struct backing_dev_info separately instead of embedding it
inside the superblock. This unifies handling of bdi among users.

CC: Miklos Szeredi <miklos@szeredi.hu>
CC: linux-fsdevel@vger.kernel.org
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

3 files changed, 17 insertions, 36 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index b681b43c766e..78887f68ee6a 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -383,8 +383,8 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 
                 if (fc->num_background == fc->congestion_threshold &&
                     fc->connected && fc->bdi_initialized) {
-                        clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
-                        clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
+                        clear_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
+                        clear_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
                 }
                 fc->num_background--;
                 fc->active_background--;
@@ -575,8 +575,8 @@ void fuse_request_send_background_locked(struct fuse_conn *fc,
                 fc->blocked = 1;
         if (fc->num_background == fc->congestion_threshold &&
             fc->bdi_initialized) {
-                set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
-                set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
+                set_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
+                set_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
         }
         list_add_tail(&req->list, &fc->bg_queue);
         flush_bg_queue(fc);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 32ac2c9b09c0..0e7c79a390e0 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -631,9 +631,6 @@ struct fuse_conn {
         /** Negotiated minor version */
         unsigned minor;
 
-        /** Backing dev info */
-        struct backing_dev_info bdi;
-
         /** Entry on the fuse_conn_list */
         struct list_head entry;
 
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 6fe6a88ecb4a..90bacbc87fb3 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -386,12 +386,6 @@ static void fuse_send_destroy(struct fuse_conn *fc)
         }
 }
 
-static void fuse_bdi_destroy(struct fuse_conn *fc)
-{
-        if (fc->bdi_initialized)
-                bdi_destroy(&fc->bdi);
-}
-
 static void fuse_put_super(struct super_block *sb)
 {
         struct fuse_conn *fc = get_fuse_conn_super(sb);
@@ -403,7 +397,6 @@ static void fuse_put_super(struct super_block *sb)
         list_del(&fc->entry);
         fuse_ctl_remove_conn(fc);
         mutex_unlock(&fuse_mutex);
-        fuse_bdi_destroy(fc);
 
         fuse_conn_put(fc);
 }
@@ -928,7 +921,8 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
                         fc->no_flock = 1;
                 }
 
-                fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
+                fc->sb->s_bdi->ra_pages =
+                                min(fc->sb->s_bdi->ra_pages, ra_pages);
                 fc->minor = arg->minor;
                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
@@ -944,7 +938,7 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 
         arg->major = FUSE_KERNEL_VERSION;
         arg->minor = FUSE_KERNEL_MINOR_VERSION;
-        arg->max_readahead = fc->bdi.ra_pages * PAGE_SIZE;
+        arg->max_readahead = fc->sb->s_bdi->ra_pages * PAGE_SIZE;
         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
@@ -976,27 +970,20 @@ static void fuse_free_conn(struct fuse_conn *fc)
 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 {
         int err;
+        char *suffix = "";
 
-        fc->bdi.name = "fuse";
-        fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
-        /* fuse does it's own writeback accounting */
-        fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
-
-        err = bdi_init(&fc->bdi);
+        if (sb->s_bdev)
+                suffix = "-fuseblk";
+        err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
+                                   MINOR(fc->dev), suffix);
         if (err)
                 return err;
 
-        fc->bdi_initialized = 1;
-
-        if (sb->s_bdev) {
-                err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
-                                    MAJOR(fc->dev), MINOR(fc->dev));
-        } else {
-                err = bdi_register_dev(&fc->bdi, fc->dev);
-        }
+        sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
+        /* fuse does it's own writeback accounting */
+        sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 
-        if (err)
-                return err;
+        fc->bdi_initialized = 1;
 
         /*
          * For a single fuse filesystem use max 1% of dirty +
@@ -1010,7 +997,7 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
          *
          *    /sys/class/bdi/<bdi>/max_ratio
          */
-        bdi_set_max_ratio(&fc->bdi, 1);
+        bdi_set_max_ratio(sb->s_bdi, 1);
 
         return 0;
 }
@@ -1113,8 +1100,6 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
         if (err)
                 goto err_dev_free;
 
-        sb->s_bdi = &fc->bdi;
-
         /* Handle umasking inside the fuse code */
         if (sb->s_flags & MS_POSIXACL)
                 fc->dont_mask = 1;
@@ -1182,7 +1167,6 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
  err_dev_free:
         fuse_dev_free(fud);
  err_put_conn:
-        fuse_bdi_destroy(fc);
         fuse_conn_put(fc);
  err_fput:
         fput(file);