@@ -446,6 +446,11 @@ void generic_shutdown_super(struct super_block *sb)
hlist_del_init(&sb->s_instances);
spin_unlock(&sb_lock);
up_write(&sb->s_umount);
+ if (sb->s_iflags & SB_I_DYNBDI) {
+ bdi_put(sb->s_bdi);
+ sb->s_bdi = &noop_backing_dev_info;
+ sb->s_iflags &= ~SB_I_DYNBDI;
+ }
}
EXPORT_SYMBOL(generic_shutdown_super);
@@ -1256,6 +1261,50 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
}
/*
+ * Setup private BDI for given superblock. It gets automatically cleaned up
+ * in generic_shutdown_super().
+ */
+int super_setup_bdi_name(struct super_block *sb, char *fmt, ...)
+{
+ struct backing_dev_info *bdi;
+ int err;
+ va_list args;
+
+ bdi = bdi_alloc(GFP_KERNEL);
+ if (!bdi)
+ return -ENOMEM;
+
+ bdi->name = sb->s_type->name;
+
+ va_start(args, fmt);
+ err = bdi_register_va(bdi, NULL, fmt, args);
+ va_end(args);
+ if (err) {
+ bdi_put(bdi);
+ return err;
+ }
+ WARN_ON(sb->s_bdi != &noop_backing_dev_info);
+ sb->s_bdi = bdi;
+ sb->s_iflags |= SB_I_DYNBDI;
+
+ return 0;
+}
+EXPORT_SYMBOL(super_setup_bdi_name);
+
+/*
+ * Setup private BDI for given superblock. I gets automatically cleaned up
+ * in generic_shutdown_super().
+ */
+int super_setup_bdi(struct super_block *sb)
+{
+ static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
+
+ return super_setup_bdi_name(sb, "%.28s-%ld", sb->s_type->name,
+ atomic_long_inc_return(&bdi_seq));
+}
+EXPORT_SYMBOL(super_setup_bdi);
+
+/*
* This is an internal function, please use sb_end_{write,pagefault,intwrite}
* instead.
*/
@@ -146,7 +146,7 @@ struct backing_dev_info {
congested_fn *congested_fn; /* Function pointer if device is md/dm */
void *congested_data; /* Pointer to aux data for congested func */
- char *name;
+ const char *name;
struct kref refcnt; /* Reference counter for the structure */
unsigned int capabilities; /* Device capabilities */
@@ -1272,6 +1272,9 @@ struct mm_struct;
/* sb->s_iflags to limit user namespace mounts */
#define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */
+/* Temporary flag until all filesystems are converted to dynamic bdis */
+#define SB_I_DYNBDI 0x00000100
+
/* Possible states of 'frozen' field */
enum {
SB_UNFROZEN = 0, /* FS is unfrozen */
@@ -2121,6 +2124,9 @@ extern int vfs_ustat(dev_t, struct kstatfs *);
extern int freeze_super(struct super_block *super);
extern int thaw_super(struct super_block *super);
extern bool our_mnt(struct vfsmount *mnt);
+extern __printf(2, 3)
+int super_setup_bdi_name(struct super_block *sb, char *fmt, ...);
+extern int super_setup_bdi(struct super_block *sb);
extern int current_umask(void);
Provide helper functions for setting up dynamically allocated backing_dev_info structures for filesystems and cleaning them up on superblock destruction. CC: linux-mtd@lists.infradead.org CC: linux-nfs@vger.kernel.org CC: Petr Vandrovec <petr@vandrovec.name> CC: linux-nilfs@vger.kernel.org CC: cluster-devel@redhat.com CC: osd-dev@open-osd.org CC: codalist@coda.cs.cmu.edu CC: linux-afs@lists.infradead.org CC: ecryptfs@vger.kernel.org CC: linux-cifs@vger.kernel.org CC: ceph-devel@vger.kernel.org CC: linux-btrfs@vger.kernel.org CC: v9fs-developer@lists.sourceforge.net CC: lustre-devel@lists.lustre.org Signed-off-by: Jan Kara <jack@suse.cz> --- fs/super.c | 49 ++++++++++++++++++++++++++++++++++++++++ include/linux/backing-dev-defs.h | 2 +- include/linux/fs.h | 6 +++++ 3 files changed, 56 insertions(+), 1 deletion(-)