On Feb 2, 2017, at 10:34, Jan Kara <jack@xxxxxxx> wrote: > > Provide helper functions for setting up dynamically allocated > backing_dev_info structures for filesystems and cleaning them up on > superblock destruction. > > CC: linux-mtd@xxxxxxxxxxxxxxxxxxx > CC: linux-nfs@xxxxxxxxxxxxxxx > CC: Petr Vandrovec <petr@xxxxxxxxxxxxxx> > CC: linux-nilfs@xxxxxxxxxxxxxxx > CC: cluster-devel@xxxxxxxxxx > CC: osd-dev@xxxxxxxxxxxx > CC: codalist@xxxxxxxxxxxxxxx > CC: linux-afs@xxxxxxxxxxxxxxxxxxx > CC: ecryptfs@xxxxxxxxxxxxxxx > CC: linux-cifs@xxxxxxxxxxxxxxx > CC: ceph-devel@xxxxxxxxxxxxxxx > CC: linux-btrfs@xxxxxxxxxxxxxxx > CC: v9fs-developer@xxxxxxxxxxxxxxxxxxxxx > CC: lustre-devel@xxxxxxxxxxxxxxxx > Signed-off-by: Jan Kara <jack@xxxxxxx> > --- > fs/super.c | 49 ++++++++++++++++++++++++++++++++++++++++ > include/linux/backing-dev-defs.h | 2 +- > include/linux/fs.h | 6 +++++ > 3 files changed, 56 insertions(+), 1 deletion(-) > > diff --git a/fs/super.c b/fs/super.c > index ea662b0e5e78..31dc4c6450ef 100644 > --- a/fs/super.c > +++ b/fs/super.c > @@ -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); > @@ -1249,6 +1254,50 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data) > } > > /* > + * Setup private BDI for given superblock. I gets automatically cleaned up (typo) s/I/It/ Looks fine otherwise. > + * 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. > */ > diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h > index 2ecafc8a2d06..70080b4217f4 100644 > --- a/include/linux/backing-dev-defs.h > +++ b/include/linux/backing-dev-defs.h > @@ -143,7 +143,7 @@ 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 registered:1; /* Is bdi registered? */ > diff --git a/include/linux/fs.h b/include/linux/fs.h > index c930cbc19342..8ed8b6d1bc54 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -1267,6 +1267,9 @@ 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 */ > @@ -2103,6 +2106,9 @@ 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); > > -- > 2.10.2 > > _______________________________________________ > lustre-devel mailing list > lustre-devel@xxxxxxxxxxxxxxxx > http://lists.lustre.org/listinfo.cgi/lustre-devel-lustre.org Cheers, Andreas -- Andreas Dilger Lustre Principal Architect Intel Corporation