cifs: Convert to separately allocated bdi

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

CC: Steve French <sfrench@samba.org>
CC: linux-cifs@vger.kernel.org
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, 6 insertions, 12 deletions

diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index 07ed81cf1552..cbd216b57239 100644
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -68,7 +68,6 @@ struct cifs_sb_info {
         umode_t mnt_dir_mode;
         unsigned int mnt_cifs_flags;
         char   *mountdata; /* options received at mount time or via DFS refs */
-        struct backing_dev_info bdi;
         struct delayed_work prune_tlinks;
         struct rcu_head rcu;
         char *prepath;
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 15e1db8738ae..502eab6bdbc4 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -138,7 +138,12 @@ cifs_read_super(struct super_block *sb)
         sb->s_magic = CIFS_MAGIC_NUMBER;
         sb->s_op = &cifs_super_ops;
         sb->s_xattr = cifs_xattr_handlers;
-        sb->s_bdi = &cifs_sb->bdi;
+        rc = super_setup_bdi(sb);
+        if (rc)
+                goto out_no_root;
+        /* tune readahead according to rsize */
+        sb->s_bdi->ra_pages = cifs_sb->rsize / PAGE_SIZE;
+
         sb->s_blocksize = CIFS_MAX_MSGSIZE;
         sb->s_blocksize_bits = 14;      /* default 2**14 = CIFS_MAX_MSGSIZE */
         inode = cifs_root_iget(sb);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 9ae695ae3ed7..7f50c8949401 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3683,10 +3683,6 @@ cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info)
         int referral_walks_count = 0;
 #endif
 
-        rc = bdi_setup_and_register(&cifs_sb->bdi, "cifs");
-        if (rc)
-                return rc;
-
 #ifdef CONFIG_CIFS_DFS_UPCALL
 try_mount_again:
         /* cleanup activities if we're chasing a referral */
@@ -3714,7 +3710,6 @@ try_mount_again:
         server = cifs_get_tcp_session(volume_info);
         if (IS_ERR(server)) {
                 rc = PTR_ERR(server);
-                bdi_destroy(&cifs_sb->bdi);
                 goto out;
         }
         if ((volume_info->max_credits < 20) ||
@@ -3768,9 +3763,6 @@ try_mount_again:
         cifs_sb->wsize = server->ops->negotiate_wsize(tcon, volume_info);
         cifs_sb->rsize = server->ops->negotiate_rsize(tcon, volume_info);
 
-        /* tune readahead according to rsize */
-        cifs_sb->bdi.ra_pages = cifs_sb->rsize / PAGE_SIZE;
-
 remote_path_check:
 #ifdef CONFIG_CIFS_DFS_UPCALL
         /*
@@ -3887,7 +3879,6 @@ mount_fail_check:
                         cifs_put_smb_ses(ses);
                 else
                         cifs_put_tcp_session(server, 0);
-                bdi_destroy(&cifs_sb->bdi);
         }
 
 out:
@@ -4090,7 +4081,6 @@ cifs_umount(struct cifs_sb_info *cifs_sb)
         }
         spin_unlock(&cifs_sb->tlink_tree_lock);
 
-        bdi_destroy(&cifs_sb->bdi);
         kfree(cifs_sb->mountdata);
         kfree(cifs_sb->prepath);
         call_rcu(&cifs_sb->rcu, delayed_free);