Linux 4.12 compat: fix super_setup_bdi_name() call

Provide a format parameter to super_setup_bdi_name() so we don't create duplicate names in '/devices/virtual/bdi' sysfs namespace which would prevent us from mounting more than one ZFS filesystem at a time. Reviewed-by: Chunwei Chen <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: loli10K <[email protected]> Closes #6147
openzfs · Jun 9, 2017 · cb8210d · cb8210d
1 parent 21fd04e
commit cb8210d
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Showing 2 changed files with 6 additions and 6 deletions.
diff --git a/include/linux/vfs_compat.h b/include/linux/vfs_compat.h
@@ -73,10 +73,13 @@ truncate_setsize(struct inode *ip, loff_t new)
  * 4.12 - x.y, super_setup_bdi_name() new interface.
  */
 #if defined(HAVE_SUPER_SETUP_BDI_NAME)
+extern atomic_long_t zfs_bdi_seq;
+
 static inline int
 zpl_bdi_setup(struct super_block *sb, char *name)
 {
-	return (super_setup_bdi_name(sb, name));
+	return super_setup_bdi_name(sb, "%.28s-%ld", name,
+	    atomic_long_inc_return(&zfs_bdi_seq));
 }
 static inline void
 zpl_bdi_destroy(struct super_block *sb)
@@ -143,7 +146,6 @@ static inline int
 zpl_bdi_setup(struct super_block *sb, char *name)
 {
 	struct backing_dev_info *bdi;
-	char tmp[32];
 	int error;
 
 	bdi = kmem_zalloc(sizeof (struct backing_dev_info), KM_SLEEP);
@@ -156,8 +158,7 @@ zpl_bdi_setup(struct super_block *sb, char *name)
 		return (error);
 	}
 
-	sprintf(tmp, "%.28s%s", name, "-%d");
-	error = bdi_register(bdi, NULL, tmp,
+	error = bdi_register(bdi, NULL, "%.28s-%ld", name,
 	    atomic_long_inc_return(&zfs_bdi_seq));
 	if (error) {
 		bdi_destroy(bdi);

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
@@ -1374,8 +1374,7 @@ zfs_sb_teardown(zfs_sb_t *zsb, boolean_t unmounting)
 }
 EXPORT_SYMBOL(zfs_sb_teardown);
 
-#if !defined(HAVE_SUPER_SETUP_BDI_NAME) && \
-	!defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER) && \
+#if !defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER) && \
 	!defined(HAVE_3ARGS_BDI_SETUP_AND_REGISTER)
 atomic_long_t zfs_bdi_seq = ATOMIC_LONG_INIT(0);
 #endif