Commit fca39346 authored by Jan Kara's avatar Jan Kara Committed by Jens Axboe

fs: Provide infrastructure for dynamic BDIs in filesystems

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
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 62bf42ad
......@@ -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);
......@@ -1255,6 +1260,50 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
return ERR_PTR(error);
}
/*
* 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);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment