diff options
| -rw-r--r-- | drivers/md/dm-table.c | 23 | ||||
| -rw-r--r-- | drivers/md/md.c | 4 | ||||
| -rw-r--r-- | fs/block_dev.c | 322 | ||||
| -rw-r--r-- | include/linux/fs.h | 16 |
4 files changed, 74 insertions, 291 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 90267f8d64ee..2c876ffc63df 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -328,12 +328,22 @@ static int open_dev(struct dm_dev_internal *d, dev_t dev, bdev = open_by_devnum(dev, d->dm_dev.mode); if (IS_ERR(bdev)) return PTR_ERR(bdev); - r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md)); - if (r) + + r = bd_claim(bdev, _claim_ptr); + if (r) { blkdev_put(bdev, d->dm_dev.mode); - else - d->dm_dev.bdev = bdev; - return r; + return r; + } + + r = bd_link_disk_holder(bdev, dm_disk(md)); + if (r) { + bd_release(bdev); + blkdev_put(bdev, d->dm_dev.mode); + return r; + } + + d->dm_dev.bdev = bdev; + return 0; } /* @@ -344,7 +354,8 @@ static void close_dev(struct dm_dev_internal *d, struct mapped_device *md) if (!d->dm_dev.bdev) return; - bd_release_from_disk(d->dm_dev.bdev, dm_disk(md)); + bd_unlink_disk_holder(d->dm_dev.bdev); + bd_release(d->dm_dev.bdev); blkdev_put(d->dm_dev.bdev, d->dm_dev.mode); d->dm_dev.bdev = NULL; } diff --git a/drivers/md/md.c b/drivers/md/md.c index 4e957f3140a8..c47644fca1a1 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1880,7 +1880,7 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev) rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state"); list_add_rcu(&rdev->same_set, &mddev->disks); - bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk); + bd_link_disk_holder(rdev->bdev, mddev->gendisk); /* May as well allow recovery to be retried once */ mddev->recovery_disabled = 0; @@ -1907,7 +1907,7 @@ static void unbind_rdev_from_array(mdk_rdev_t * rdev) MD_BUG(); return; } - bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk); + bd_unlink_disk_holder(rdev->bdev); list_del_rcu(&rdev->same_set); printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b)); rdev->mddev = NULL; diff --git a/fs/block_dev.c b/fs/block_dev.c index 06e8ff12b97c..9329068684d2 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -426,9 +426,6 @@ static void init_once(void *foo) mutex_init(&bdev->bd_mutex); INIT_LIST_HEAD(&bdev->bd_inodes); INIT_LIST_HEAD(&bdev->bd_list); -#ifdef CONFIG_SYSFS - INIT_LIST_HEAD(&bdev->bd_holder_list); -#endif inode_init_once(&ei->vfs_inode); /* Initialize mutex for freeze. */ mutex_init(&bdev->bd_fsfreeze_mutex); @@ -881,314 +878,83 @@ void bd_release(struct block_device *bdev) EXPORT_SYMBOL(bd_release); #ifdef CONFIG_SYSFS -/* - * Functions for bd_claim_by_kobject / bd_release_from_kobject - * - * If a kobject is passed to bd_claim_by_kobject() - * and the kobject has a parent directory, - * following symlinks are created: - * o from the kobject to the claimed bdev - * o from "holders" directory of the bdev to the parent of the kobject - * bd_release_from_kobject() removes these symlinks. - * - * Example: - * If /dev/dm-0 maps to /dev/sda, kobject corresponding to - * /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then: - * /sys/block/dm-0/slaves/sda --> /sys/block/sda - * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 - */ - static int add_symlink(struct kobject *from, struct kobject *to) { - if (!from || !to) - return 0; return sysfs_create_link(from, to, kobject_name(to)); } static void del_symlink(struct kobject *from, struct kobject *to) { - if (!from || !to) - return; sysfs_remove_link(from, kobject_name(to)); } -/* - * 'struct bd_holder' contains pointers to kobjects symlinked by - * bd_claim_by_kobject. - * It's connected to bd_holder_list which is protected by bdev->bd_sem. - */ -struct bd_holder { - struct list_head list; /* chain of holders of the bdev */ - int count; /* references from the holder */ - struct kobject *sdir; /* holder object, e.g. "/block/dm-0/slaves" */ - struct kobject *hdev; /* e.g. "/block/dm-0" */ - struct kobject *hdir; /* e.g. "/block/sda/holders" */ - struct kobject *sdev; /* e.g. "/block/sda" */ -}; - -/* - * Get references of related kobjects at once. - * Returns 1 on success. 0 on failure. - * - * Should call bd_holder_release_dirs() after successful use. - */ -static int bd_holder_grab_dirs(struct block_device *bdev, - struct bd_holder *bo) -{ - if (!bdev || !bo) - return 0; - - bo->sdir = kobject_get(bo->sdir); - if (!bo->sdir) - return 0; - - bo->hdev = kobject_get(bo->sdir->parent); - if (!bo->hdev) - goto fail_put_sdir; - - bo->sdev = kobject_get(&part_to_dev(bdev->bd_part)->kobj); - if (!bo->sdev) - goto fail_put_hdev; - - bo->hdir = kobject_get(bdev->bd_part->holder_dir); - if (!bo->hdir) - goto fail_put_sdev; - - return 1; - -fail_put_sdev: - kobject_put(bo->sdev); -fail_put_hdev: - kobject_put(bo->hdev); -fail_put_sdir: - kobject_put(bo->sdir); - - return 0; -} - -/* Put references of related kobjects at once. */ -static void bd_holder_release_dirs(struct bd_holder *bo) -{ - kobject_put(bo->hdir); - kobject_put(bo->sdev); - kobject_put(bo->hdev); - kobject_put(bo->sdir); -} - -static struct bd_holder *alloc_bd_holder(struct kobject *kobj) -{ - struct bd_holder *bo; - - bo = kzalloc(sizeof(*bo), GFP_KERNEL); - if (!bo) - return NULL; - - bo->count = 1; - bo->sdir = kobj; - - return bo; -} - -static void free_bd_holder(struct bd_holder *bo) -{ - kfree(bo); -} - /** - * find_bd_holder - find matching struct bd_holder from the block device + * bd_link_disk_holder - create symlinks between holding disk and slave bdev + * @bdev: the claimed slave bdev + * @disk: the holding disk * - * @bdev: struct block device to be searched - * @bo: target struct bd_holder + * This functions creates the following sysfs symlinks. * - * Returns matching entry with @bo in @bdev->bd_holder_list. - * If found, increment the reference count and return the pointer. - * If not found, returns NULL. - */ -static struct bd_holder *find_bd_holder(struct block_device *bdev, - struct bd_holder *bo) -{ - struct bd_holder *tmp; - - list_for_each_entry(tmp, &bdev->bd_holder_list, list) - if (tmp->sdir == bo->sdir) { - tmp->count++; - return tmp; - } - - return NULL; -} - -/** - * add_bd_holder - create sysfs symlinks for bd_claim() relationship + * - from "slaves" directory of the holder @disk to the claimed @bdev + * - from "holders" directory of the @bdev to the holder @disk * - * @bdev: block device to be bd_claimed - * @bo: preallocated and initialized by alloc_bd_holder() + * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is + * passed to bd_link_disk_holder(), then: * - * Add @bo to @bdev->bd_holder_list, create symlinks. + * /sys/block/dm-0/slaves/sda --> /sys/block/sda + * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 * - * Returns 0 if symlinks are created. - * Returns -ve if something fails. - */ -static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo) -{ - int err; - - if (!bo) - return -EINVAL; - - if (!bd_holder_grab_dirs(bdev, bo)) - return -EBUSY; - - err = add_symlink(bo->sdir, bo->sdev); - if (err) - return err; - - err = add_symlink(bo->hdir, bo->hdev); - if (err) { - del_symlink(bo->sdir, bo->sdev); - return err; - } - - list_add_tail(&bo->list, &bdev->bd_holder_list); - return 0; -} - -/** - * del_bd_holder - delete sysfs symlinks for bd_claim() relationship - * - * @bdev: block device to be bd_claimed - * @kobj: holder's kobject - * - * If there is matching entry with @kobj in @bdev->bd_holder_list - * and no other bd_claim() from the same kobject, - * remove the struct bd_holder from the list, delete symlinks for it. - * - * Returns a pointer to the struct bd_holder when it's removed from the list - * and ready to be freed. - * Returns NULL if matching claim isn't found or there is other bd_claim() - * by the same kobject. - */ -static struct bd_holder *del_bd_holder(struct block_device *bdev, - struct kobject *kobj) -{ - struct bd_holder *bo; - - list_for_each_entry(bo, &bdev->bd_holder_list, list) { - if (bo->sdir == kobj) { - bo->count--; - BUG_ON(bo->count < 0); - if (!bo->count) { - list_del(&bo->list); - del_symlink(bo->sdir, bo->sdev); - del_symlink(bo->hdir, bo->hdev); - bd_holder_release_dirs(bo); - return bo; - } - break; - } - } - - return NULL; -} - -/** - * bd_claim_by_kobject - bd_claim() with additional kobject signature - * - * @bdev: block device to be claimed - * @holder: holder's signature - * @kobj: holder's kobject + * The caller must have claimed @bdev before calling this function and + * ensure that both @bdev and @disk are valid during the creation and + * lifetime of these symlinks. * - * Do bd_claim() and if it succeeds, create sysfs symlinks between - * the bdev and the holder's kobject. - * Use bd_release_from_kobject() when relesing the claimed bdev. + * CONTEXT: + * Might sleep. * - * Returns 0 on success. (same as bd_claim()) - * Returns errno on failure. + * RETURNS: + * 0 on success, -errno on failure. */ -static int bd_claim_by_kobject(struct block_device *bdev, void *holder, - struct kobject *kobj) +int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) { - int err; - struct bd_holder *bo, *found; - - if (!kobj) - return -EINVAL; - - bo = alloc_bd_holder(kobj); - if (!bo) - return -ENOMEM; + int ret = 0; mutex_lock(&bdev->bd_mutex); - err = bd_claim(bdev, holder); - if (err) - goto fail; + WARN_ON_ONCE(!bdev->bd_holder || bdev->bd_holder_disk); - found = find_bd_holder(bdev, bo); - if (found) - goto fail; + /* FIXME: remove the following once add_disk() handles errors */ + if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) + goto out_unlock; - err = add_bd_holder(bdev, bo); - if (err) - bd_release(bdev); - else - bo = NULL; -fail: - mutex_unlock(&bdev->bd_mutex); - free_bd_holder(bo); - return err; -} + ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); + if (ret) + goto out_unlock; -/** - * bd_release_from_kobject - bd_release() with additional kobject signature - * - * @bdev: block device to be released - * @kobj: holder's kobject - * - * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject(). - */ -static void bd_release_from_kobject(struct block_device *bdev, - struct kobject *kobj) -{ - if (!kobj) - return; + ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); + if (ret) { + del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); + goto out_unlock; + } - mutex_lock(&bdev->bd_mutex); - bd_release(bdev); - free_bd_holder(del_bd_holder(bdev, kobj)); + bdev->bd_holder_disk = disk; +out_unlock: mutex_unlock(&bdev->bd_mutex); + return ret; } +EXPORT_SYMBOL_GPL(bd_link_disk_holder); -/** - * bd_claim_by_disk - wrapper function for bd_claim_by_kobject() - * - * @bdev: block device to be claimed - * @holder: holder's signature - * @disk: holder's gendisk - * - * Call bd_claim_by_kobject() with getting @disk->slave_dir. - */ -int bd_claim_by_disk(struct block_device *bdev, void *holder, - struct gendisk *disk) +void bd_unlink_disk_holder(struct block_device *bdev) { - return bd_claim_by_kobject(bdev, holder, kobject_get(disk->slave_dir)); -} -EXPORT_SYMBOL_GPL(bd_claim_by_disk); + struct gendisk *disk = bdev->bd_holder_disk; -/** - * bd_release_from_disk - wrapper function for bd_release_from_kobject() - * - * @bdev: block device to be claimed - * @disk: holder's gendisk - * - * Call bd_release_from_kobject() and put @disk->slave_dir. - */ -void bd_release_from_disk(struct block_device *bdev, struct gendisk *disk) -{ - bd_release_from_kobject(bdev, disk->slave_dir); - kobject_put(disk->slave_dir); + bdev->bd_holder_disk = NULL; + if (!disk) + return; + + del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); + del_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); } -EXPORT_SYMBOL_GPL(bd_release_from_disk); +EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); #endif /* diff --git a/include/linux/fs.h b/include/linux/fs.h index 334d68a17108..66b7f2c5d7e9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -663,7 +663,7 @@ struct block_device { void * bd_holder; int bd_holders; #ifdef CONFIG_SYSFS - struct list_head bd_holder_list; + struct gendisk * bd_holder_disk; /* for sysfs slave linkng */ #endif struct block_device * bd_contains; unsigned bd_block_size; @@ -2042,11 +2042,17 @@ extern int blkdev_put(struct block_device *, fmode_t); extern int bd_claim(struct block_device *, void *); extern void bd_release(struct block_device *); #ifdef CONFIG_SYSFS -extern int bd_claim_by_disk(struct block_device *, void *, struct gendisk *); -extern void bd_release_from_disk(struct block_device *, struct gendisk *); +extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk); +extern void bd_unlink_disk_holder(struct block_device *bdev); #else -#define bd_claim_by_disk(bdev, holder, disk) bd_claim(bdev, holder) -#define bd_release_from_disk(bdev, disk) bd_release(bdev) +static inline int bd_link_disk_holder(struct block_device *bdev, + struct gendisk *disk) +{ + return 0; +} +static inline void bd_unlink_disk_holder(struct block_device *bdev) +{ +} #endif #endif |