diff options
| -rw-r--r-- | drivers/mtd/mtdsuper.c | 45 | ||||
| -rw-r--r-- | fs/nfs/super.c | 4 | ||||
| -rw-r--r-- | fs/super.c | 64 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 |
4 files changed, 58 insertions, 56 deletions
diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c index 5ff001140ef4..b7e3763c47f0 100644 --- a/drivers/mtd/mtdsuper.c +++ b/drivers/mtd/mtdsuper.c @@ -20,38 +20,6 @@ #include "mtdcore.h" /* - * compare superblocks to see if they're equivalent - * - they are if the underlying MTD device is the same - */ -static int mtd_test_super(struct super_block *sb, struct fs_context *fc) -{ - struct mtd_info *mtd = fc->sget_key; - - if (sb->s_mtd == fc->sget_key) { - pr_debug("MTDSB: Match on device %d (\"%s\")\n", - mtd->index, mtd->name); - return 1; - } - - pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n", - sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name); - return 0; -} - -/* - * mark the superblock by the MTD device it is using - * - set the device number to be the correct MTD block device for pesuperstence - * of NFS exports - */ -static int mtd_set_super(struct super_block *sb, struct fs_context *fc) -{ - sb->s_mtd = fc->sget_key; - sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, sb->s_mtd->index); - sb->s_bdi = bdi_get(mtd_bdi); - return 0; -} - -/* * get a superblock on an MTD-backed filesystem */ static int mtd_get_sb(struct fs_context *fc, @@ -62,8 +30,7 @@ static int mtd_get_sb(struct fs_context *fc, struct super_block *sb; int ret; - fc->sget_key = mtd; - sb = sget_fc(fc, mtd_test_super, mtd_set_super); + sb = sget_dev(fc, MKDEV(MTD_BLOCK_MAJOR, mtd->index)); if (IS_ERR(sb)) return PTR_ERR(sb); @@ -77,6 +44,16 @@ static int mtd_get_sb(struct fs_context *fc, pr_debug("MTDSB: New superblock for device %d (\"%s\")\n", mtd->index, mtd->name); + /* + * Would usually have been set with @sb_lock held but in + * contrast to sb->s_bdev that's checked with only + * @sb_lock held, nothing checks sb->s_mtd without also + * holding sb->s_umount and we're holding sb->s_umount + * here. + */ + sb->s_mtd = mtd; + sb->s_bdi = bdi_get(mtd_bdi); + ret = fill_super(sb, fc); if (ret < 0) goto error_sb; diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 2284f749d892..0d6473cb00cb 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1339,15 +1339,13 @@ error_splat_super: void nfs_kill_super(struct super_block *s) { struct nfs_server *server = NFS_SB(s); - dev_t dev = s->s_dev; nfs_sysfs_move_sb_to_server(server); - generic_shutdown_super(s); + kill_anon_super(s); nfs_fscache_release_super_cookie(s); nfs_free_server(server); - free_anon_bdev(dev); } EXPORT_SYMBOL_GPL(nfs_kill_super); diff --git a/fs/super.c b/fs/super.c index bd8dcfc822c3..2d762ce67f6e 100644 --- a/fs/super.c +++ b/fs/super.c @@ -1373,6 +1373,50 @@ int get_tree_keyed(struct fs_context *fc, } EXPORT_SYMBOL(get_tree_keyed); +static int set_bdev_super(struct super_block *s, void *data) +{ + s->s_dev = *(dev_t *)data; + return 0; +} + +static int super_s_dev_set(struct super_block *s, struct fs_context *fc) +{ + return set_bdev_super(s, fc->sget_key); +} + +static int super_s_dev_test(struct super_block *s, struct fs_context *fc) +{ + return !(s->s_iflags & SB_I_RETIRED) && + s->s_dev == *(dev_t *)fc->sget_key; +} + +/** + * sget_dev - Find or create a superblock by device number + * @fc: Filesystem context. + * @dev: device number + * + * Find or create a superblock using the provided device number that + * will be stored in fc->sget_key. + * + * If an extant superblock is matched, then that will be returned with + * an elevated reference count that the caller must transfer or discard. + * + * If no match is made, a new superblock will be allocated and basic + * initialisation will be performed (s_type, s_fs_info, s_id, s_dev will + * be set). The superblock will be published and it will be returned in + * a partially constructed state with SB_BORN and SB_ACTIVE as yet + * unset. + * + * Return: an existing or newly created superblock on success, an error + * pointer on failure. + */ +struct super_block *sget_dev(struct fs_context *fc, dev_t dev) +{ + fc->sget_key = &dev; + return sget_fc(fc, super_s_dev_test, super_s_dev_set); +} +EXPORT_SYMBOL(sget_dev); + #ifdef CONFIG_BLOCK /* * Lock a super block that the callers holds a reference to. @@ -1431,23 +1475,6 @@ const struct blk_holder_ops fs_holder_ops = { }; EXPORT_SYMBOL_GPL(fs_holder_ops); -static int set_bdev_super(struct super_block *s, void *data) -{ - s->s_dev = *(dev_t *)data; - return 0; -} - -static int set_bdev_super_fc(struct super_block *s, struct fs_context *fc) -{ - return set_bdev_super(s, fc->sget_key); -} - -static int test_bdev_super_fc(struct super_block *s, struct fs_context *fc) -{ - return !(s->s_iflags & SB_I_RETIRED) && - s->s_dev == *(dev_t *)fc->sget_key; -} - int setup_bdev_super(struct super_block *sb, int sb_flags, struct fs_context *fc) { @@ -1525,8 +1552,7 @@ int get_tree_bdev(struct fs_context *fc, } fc->sb_flags |= SB_NOSEC; - fc->sget_key = &dev; - s = sget_fc(fc, test_bdev_super_fc, set_bdev_super_fc); + s = sget_dev(fc, dev); if (IS_ERR(s)) return PTR_ERR(s); diff --git a/include/linux/fs.h b/include/linux/fs.h index c8ff4156a0a1..4aeb3fa11927 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2397,6 +2397,7 @@ struct super_block *sget(struct file_system_type *type, int (*test)(struct super_block *,void *), int (*set)(struct super_block *,void *), int flags, void *data); +struct super_block *sget_dev(struct fs_context *fc, dev_t dev); /* Alas, no aliases. Too much hassle with bringing module.h everywhere */ #define fops_get(fops) \ |