From: Christoph Hellwig <hch@lst.de> To: Jens Axboe <axboe@kernel.dk>, Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com, linux-block@vger.kernel.org Subject: [PATCH 1/8] block: make the block holder code optional Date: Wed, 4 Aug 2021 11:41:40 +0200 [thread overview] Message-ID: <20210804094147.459763-2-hch@lst.de> (raw) In-Reply-To: <20210804094147.459763-1-hch@lst.de> Move the block holder code into a separate file as it is not in any way related to the other block_dev.c code, and add a new selectable config option for it so that we don't have to build it without any remapped drivers selected. The Kconfig symbol contains a _DEPRECATED suffix to match the comments added in commit 49731baa41df ("block: restore multiple bd_link_disk_holder() support"). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> --- block/Kconfig | 4 ++ block/Makefile | 1 + block/holder.c | 139 ++++++++++++++++++++++++++++++++++++ drivers/md/Kconfig | 2 + drivers/md/bcache/Kconfig | 1 + fs/block_dev.c | 144 +------------------------------------- include/linux/blk_types.h | 2 +- include/linux/genhd.h | 4 +- 8 files changed, 151 insertions(+), 146 deletions(-) create mode 100644 block/holder.c diff --git a/block/Kconfig b/block/Kconfig index 15dfb7660645..bac87d773c54 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -241,4 +241,8 @@ config BLK_MQ_RDMA config BLK_PM def_bool BLOCK && PM +# do not use in new code +config BLOCK_HOLDER_DEPRECATED + bool + source "block/Kconfig.iosched" diff --git a/block/Makefile b/block/Makefile index c72592b4cf31..0d951adce796 100644 --- a/block/Makefile +++ b/block/Makefile @@ -41,3 +41,4 @@ obj-$(CONFIG_BLK_SED_OPAL) += sed-opal.o obj-$(CONFIG_BLK_PM) += blk-pm.o obj-$(CONFIG_BLK_INLINE_ENCRYPTION) += keyslot-manager.o blk-crypto.o obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) += blk-crypto-fallback.o +obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED) += holder.o diff --git a/block/holder.c b/block/holder.c new file mode 100644 index 000000000000..904a1dcd5c12 --- /dev/null +++ b/block/holder.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/genhd.h> + +struct bd_holder_disk { + struct list_head list; + struct gendisk *disk; + int refcnt; +}; + +static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, + struct gendisk *disk) +{ + struct bd_holder_disk *holder; + + list_for_each_entry(holder, &bdev->bd_holder_disks, list) + if (holder->disk == disk) + return holder; + return NULL; +} + +static int add_symlink(struct kobject *from, struct kobject *to) +{ + return sysfs_create_link(from, to, kobject_name(to)); +} + +static void del_symlink(struct kobject *from, struct kobject *to) +{ + sysfs_remove_link(from, kobject_name(to)); +} + +/** + * bd_link_disk_holder - create symlinks between holding disk and slave bdev + * @bdev: the claimed slave bdev + * @disk: the holding disk + * + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. + * + * This functions creates the following sysfs symlinks. + * + * - from "slaves" directory of the holder @disk to the claimed @bdev + * - from "holders" directory of the @bdev to the holder @disk + * + * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is + * passed to bd_link_disk_holder(), then: + * + * /sys/block/dm-0/slaves/sda --> /sys/block/sda + * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 + * + * 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. + * + * CONTEXT: + * Might sleep. + * + * RETURNS: + * 0 on success, -errno on failure. + */ +int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) +{ + struct bd_holder_disk *holder; + int ret = 0; + + mutex_lock(&bdev->bd_disk->open_mutex); + + WARN_ON_ONCE(!bdev->bd_holder); + + /* FIXME: remove the following once add_disk() handles errors */ + if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) + goto out_unlock; + + holder = bd_find_holder_disk(bdev, disk); + if (holder) { + holder->refcnt++; + goto out_unlock; + } + + holder = kzalloc(sizeof(*holder), GFP_KERNEL); + if (!holder) { + ret = -ENOMEM; + goto out_unlock; + } + + INIT_LIST_HEAD(&holder->list); + holder->disk = disk; + holder->refcnt = 1; + + ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); + if (ret) + goto out_free; + + ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); + if (ret) + goto out_del; + /* + * bdev could be deleted beneath us which would implicitly destroy + * the holder directory. Hold on to it. + */ + kobject_get(bdev->bd_holder_dir); + + list_add(&holder->list, &bdev->bd_holder_disks); + goto out_unlock; + +out_del: + del_symlink(disk->slave_dir, bdev_kobj(bdev)); +out_free: + kfree(holder); +out_unlock: + mutex_unlock(&bdev->bd_disk->open_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(bd_link_disk_holder); + +/** + * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() + * @bdev: the calimed slave bdev + * @disk: the holding disk + * + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. + * + * CONTEXT: + * Might sleep. + */ +void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) +{ + struct bd_holder_disk *holder; + + mutex_lock(&bdev->bd_disk->open_mutex); + holder = bd_find_holder_disk(bdev, disk); + if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { + del_symlink(disk->slave_dir, bdev_kobj(bdev)); + del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); + kobject_put(bdev->bd_holder_dir); + list_del_init(&holder->list); + kfree(holder); + } + mutex_unlock(&bdev->bd_disk->open_mutex); +} +EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 0602e82a9516..f821dae101a9 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -15,6 +15,7 @@ if MD config BLK_DEV_MD tristate "RAID support" + select BLOCK_HOLDER_DEPRECATED if SYSFS help This driver lets you combine several hard disk partitions into one logical block device. This can be used to simply append one @@ -201,6 +202,7 @@ config BLK_DEV_DM_BUILTIN config BLK_DEV_DM tristate "Device mapper support" + select BLOCK_HOLDER_DEPRECATED if SYSFS select BLK_DEV_DM_BUILTIN depends on DAX || DAX=n help diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig index d1ca4d059c20..cf3e8096942a 100644 --- a/drivers/md/bcache/Kconfig +++ b/drivers/md/bcache/Kconfig @@ -2,6 +2,7 @@ config BCACHE tristate "Block device as cache" + select BLOCK_HOLDER_DEPRECATED if SYSFS select CRC64 help Allows a block device to be used as cache for other devices; uses diff --git a/fs/block_dev.c b/fs/block_dev.c index 6658f40ae492..ae9651cad923 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -902,7 +902,7 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) bdev->bd_disk = disk; bdev->bd_partno = partno; bdev->bd_inode = inode; -#ifdef CONFIG_SYSFS +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED INIT_LIST_HEAD(&bdev->bd_holder_disks); #endif bdev->bd_stats = alloc_percpu(struct disk_stats); @@ -1063,148 +1063,6 @@ void bd_abort_claiming(struct block_device *bdev, void *holder) } EXPORT_SYMBOL(bd_abort_claiming); -#ifdef CONFIG_SYSFS -struct bd_holder_disk { - struct list_head list; - struct gendisk *disk; - int refcnt; -}; - -static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, - struct gendisk *disk) -{ - struct bd_holder_disk *holder; - - list_for_each_entry(holder, &bdev->bd_holder_disks, list) - if (holder->disk == disk) - return holder; - return NULL; -} - -static int add_symlink(struct kobject *from, struct kobject *to) -{ - return sysfs_create_link(from, to, kobject_name(to)); -} - -static void del_symlink(struct kobject *from, struct kobject *to) -{ - sysfs_remove_link(from, kobject_name(to)); -} - -/** - * bd_link_disk_holder - create symlinks between holding disk and slave bdev - * @bdev: the claimed slave bdev - * @disk: the holding disk - * - * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. - * - * This functions creates the following sysfs symlinks. - * - * - from "slaves" directory of the holder @disk to the claimed @bdev - * - from "holders" directory of the @bdev to the holder @disk - * - * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is - * passed to bd_link_disk_holder(), then: - * - * /sys/block/dm-0/slaves/sda --> /sys/block/sda - * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 - * - * 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. - * - * CONTEXT: - * Might sleep. - * - * RETURNS: - * 0 on success, -errno on failure. - */ -int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) -{ - struct bd_holder_disk *holder; - int ret = 0; - - mutex_lock(&bdev->bd_disk->open_mutex); - - WARN_ON_ONCE(!bdev->bd_holder); - - /* FIXME: remove the following once add_disk() handles errors */ - if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) - goto out_unlock; - - holder = bd_find_holder_disk(bdev, disk); - if (holder) { - holder->refcnt++; - goto out_unlock; - } - - holder = kzalloc(sizeof(*holder), GFP_KERNEL); - if (!holder) { - ret = -ENOMEM; - goto out_unlock; - } - - INIT_LIST_HEAD(&holder->list); - holder->disk = disk; - holder->refcnt = 1; - - ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); - if (ret) - goto out_free; - - ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); - if (ret) - goto out_del; - /* - * bdev could be deleted beneath us which would implicitly destroy - * the holder directory. Hold on to it. - */ - kobject_get(bdev->bd_holder_dir); - - list_add(&holder->list, &bdev->bd_holder_disks); - goto out_unlock; - -out_del: - del_symlink(disk->slave_dir, bdev_kobj(bdev)); -out_free: - kfree(holder); -out_unlock: - mutex_unlock(&bdev->bd_disk->open_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(bd_link_disk_holder); - -/** - * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() - * @bdev: the calimed slave bdev - * @disk: the holding disk - * - * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. - * - * CONTEXT: - * Might sleep. - */ -void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) -{ - struct bd_holder_disk *holder; - - mutex_lock(&bdev->bd_disk->open_mutex); - - holder = bd_find_holder_disk(bdev, disk); - - if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { - del_symlink(disk->slave_dir, bdev_kobj(bdev)); - del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); - kobject_put(bdev->bd_holder_dir); - list_del_init(&holder->list); - kfree(holder); - } - - mutex_unlock(&bdev->bd_disk->open_mutex); -} -EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); -#endif - static void blkdev_flush_mapping(struct block_device *bdev) { WARN_ON_ONCE(bdev->bd_holders); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 290f9061b29a..7a4e139d24ef 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -34,7 +34,7 @@ struct block_device { void * bd_holder; int bd_holders; bool bd_write_holder; -#ifdef CONFIG_SYSFS +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED struct list_head bd_holder_disks; #endif struct kobject *bd_holder_dir; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 849486de81c6..e21a91c16a79 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -318,7 +318,7 @@ void set_capacity(struct gendisk *disk, sector_t size); int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long); long compat_blkdev_ioctl(struct file *, unsigned, unsigned long); -#ifdef CONFIG_SYSFS +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk); void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk); #else @@ -331,7 +331,7 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) { } -#endif /* CONFIG_SYSFS */ +#endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */ dev_t part_devt(struct gendisk *disk, u8 partno); void inc_diskseq(struct gendisk *disk); -- 2.30.2
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de> To: Jens Axboe <axboe@kernel.dk>, Mike Snitzer <snitzer@redhat.com> Cc: linux-block@vger.kernel.org, dm-devel@redhat.com Subject: [dm-devel] [PATCH 1/8] block: make the block holder code optional Date: Wed, 4 Aug 2021 11:41:40 +0200 [thread overview] Message-ID: <20210804094147.459763-2-hch@lst.de> (raw) In-Reply-To: <20210804094147.459763-1-hch@lst.de> Move the block holder code into a separate file as it is not in any way related to the other block_dev.c code, and add a new selectable config option for it so that we don't have to build it without any remapped drivers selected. The Kconfig symbol contains a _DEPRECATED suffix to match the comments added in commit 49731baa41df ("block: restore multiple bd_link_disk_holder() support"). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> --- block/Kconfig | 4 ++ block/Makefile | 1 + block/holder.c | 139 ++++++++++++++++++++++++++++++++++++ drivers/md/Kconfig | 2 + drivers/md/bcache/Kconfig | 1 + fs/block_dev.c | 144 +------------------------------------- include/linux/blk_types.h | 2 +- include/linux/genhd.h | 4 +- 8 files changed, 151 insertions(+), 146 deletions(-) create mode 100644 block/holder.c diff --git a/block/Kconfig b/block/Kconfig index 15dfb7660645..bac87d773c54 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -241,4 +241,8 @@ config BLK_MQ_RDMA config BLK_PM def_bool BLOCK && PM +# do not use in new code +config BLOCK_HOLDER_DEPRECATED + bool + source "block/Kconfig.iosched" diff --git a/block/Makefile b/block/Makefile index c72592b4cf31..0d951adce796 100644 --- a/block/Makefile +++ b/block/Makefile @@ -41,3 +41,4 @@ obj-$(CONFIG_BLK_SED_OPAL) += sed-opal.o obj-$(CONFIG_BLK_PM) += blk-pm.o obj-$(CONFIG_BLK_INLINE_ENCRYPTION) += keyslot-manager.o blk-crypto.o obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) += blk-crypto-fallback.o +obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED) += holder.o diff --git a/block/holder.c b/block/holder.c new file mode 100644 index 000000000000..904a1dcd5c12 --- /dev/null +++ b/block/holder.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/genhd.h> + +struct bd_holder_disk { + struct list_head list; + struct gendisk *disk; + int refcnt; +}; + +static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, + struct gendisk *disk) +{ + struct bd_holder_disk *holder; + + list_for_each_entry(holder, &bdev->bd_holder_disks, list) + if (holder->disk == disk) + return holder; + return NULL; +} + +static int add_symlink(struct kobject *from, struct kobject *to) +{ + return sysfs_create_link(from, to, kobject_name(to)); +} + +static void del_symlink(struct kobject *from, struct kobject *to) +{ + sysfs_remove_link(from, kobject_name(to)); +} + +/** + * bd_link_disk_holder - create symlinks between holding disk and slave bdev + * @bdev: the claimed slave bdev + * @disk: the holding disk + * + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. + * + * This functions creates the following sysfs symlinks. + * + * - from "slaves" directory of the holder @disk to the claimed @bdev + * - from "holders" directory of the @bdev to the holder @disk + * + * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is + * passed to bd_link_disk_holder(), then: + * + * /sys/block/dm-0/slaves/sda --> /sys/block/sda + * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 + * + * 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. + * + * CONTEXT: + * Might sleep. + * + * RETURNS: + * 0 on success, -errno on failure. + */ +int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) +{ + struct bd_holder_disk *holder; + int ret = 0; + + mutex_lock(&bdev->bd_disk->open_mutex); + + WARN_ON_ONCE(!bdev->bd_holder); + + /* FIXME: remove the following once add_disk() handles errors */ + if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) + goto out_unlock; + + holder = bd_find_holder_disk(bdev, disk); + if (holder) { + holder->refcnt++; + goto out_unlock; + } + + holder = kzalloc(sizeof(*holder), GFP_KERNEL); + if (!holder) { + ret = -ENOMEM; + goto out_unlock; + } + + INIT_LIST_HEAD(&holder->list); + holder->disk = disk; + holder->refcnt = 1; + + ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); + if (ret) + goto out_free; + + ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); + if (ret) + goto out_del; + /* + * bdev could be deleted beneath us which would implicitly destroy + * the holder directory. Hold on to it. + */ + kobject_get(bdev->bd_holder_dir); + + list_add(&holder->list, &bdev->bd_holder_disks); + goto out_unlock; + +out_del: + del_symlink(disk->slave_dir, bdev_kobj(bdev)); +out_free: + kfree(holder); +out_unlock: + mutex_unlock(&bdev->bd_disk->open_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(bd_link_disk_holder); + +/** + * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() + * @bdev: the calimed slave bdev + * @disk: the holding disk + * + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. + * + * CONTEXT: + * Might sleep. + */ +void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) +{ + struct bd_holder_disk *holder; + + mutex_lock(&bdev->bd_disk->open_mutex); + holder = bd_find_holder_disk(bdev, disk); + if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { + del_symlink(disk->slave_dir, bdev_kobj(bdev)); + del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); + kobject_put(bdev->bd_holder_dir); + list_del_init(&holder->list); + kfree(holder); + } + mutex_unlock(&bdev->bd_disk->open_mutex); +} +EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 0602e82a9516..f821dae101a9 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -15,6 +15,7 @@ if MD config BLK_DEV_MD tristate "RAID support" + select BLOCK_HOLDER_DEPRECATED if SYSFS help This driver lets you combine several hard disk partitions into one logical block device. This can be used to simply append one @@ -201,6 +202,7 @@ config BLK_DEV_DM_BUILTIN config BLK_DEV_DM tristate "Device mapper support" + select BLOCK_HOLDER_DEPRECATED if SYSFS select BLK_DEV_DM_BUILTIN depends on DAX || DAX=n help diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig index d1ca4d059c20..cf3e8096942a 100644 --- a/drivers/md/bcache/Kconfig +++ b/drivers/md/bcache/Kconfig @@ -2,6 +2,7 @@ config BCACHE tristate "Block device as cache" + select BLOCK_HOLDER_DEPRECATED if SYSFS select CRC64 help Allows a block device to be used as cache for other devices; uses diff --git a/fs/block_dev.c b/fs/block_dev.c index 6658f40ae492..ae9651cad923 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -902,7 +902,7 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) bdev->bd_disk = disk; bdev->bd_partno = partno; bdev->bd_inode = inode; -#ifdef CONFIG_SYSFS +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED INIT_LIST_HEAD(&bdev->bd_holder_disks); #endif bdev->bd_stats = alloc_percpu(struct disk_stats); @@ -1063,148 +1063,6 @@ void bd_abort_claiming(struct block_device *bdev, void *holder) } EXPORT_SYMBOL(bd_abort_claiming); -#ifdef CONFIG_SYSFS -struct bd_holder_disk { - struct list_head list; - struct gendisk *disk; - int refcnt; -}; - -static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, - struct gendisk *disk) -{ - struct bd_holder_disk *holder; - - list_for_each_entry(holder, &bdev->bd_holder_disks, list) - if (holder->disk == disk) - return holder; - return NULL; -} - -static int add_symlink(struct kobject *from, struct kobject *to) -{ - return sysfs_create_link(from, to, kobject_name(to)); -} - -static void del_symlink(struct kobject *from, struct kobject *to) -{ - sysfs_remove_link(from, kobject_name(to)); -} - -/** - * bd_link_disk_holder - create symlinks between holding disk and slave bdev - * @bdev: the claimed slave bdev - * @disk: the holding disk - * - * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. - * - * This functions creates the following sysfs symlinks. - * - * - from "slaves" directory of the holder @disk to the claimed @bdev - * - from "holders" directory of the @bdev to the holder @disk - * - * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is - * passed to bd_link_disk_holder(), then: - * - * /sys/block/dm-0/slaves/sda --> /sys/block/sda - * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 - * - * 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. - * - * CONTEXT: - * Might sleep. - * - * RETURNS: - * 0 on success, -errno on failure. - */ -int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) -{ - struct bd_holder_disk *holder; - int ret = 0; - - mutex_lock(&bdev->bd_disk->open_mutex); - - WARN_ON_ONCE(!bdev->bd_holder); - - /* FIXME: remove the following once add_disk() handles errors */ - if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) - goto out_unlock; - - holder = bd_find_holder_disk(bdev, disk); - if (holder) { - holder->refcnt++; - goto out_unlock; - } - - holder = kzalloc(sizeof(*holder), GFP_KERNEL); - if (!holder) { - ret = -ENOMEM; - goto out_unlock; - } - - INIT_LIST_HEAD(&holder->list); - holder->disk = disk; - holder->refcnt = 1; - - ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); - if (ret) - goto out_free; - - ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); - if (ret) - goto out_del; - /* - * bdev could be deleted beneath us which would implicitly destroy - * the holder directory. Hold on to it. - */ - kobject_get(bdev->bd_holder_dir); - - list_add(&holder->list, &bdev->bd_holder_disks); - goto out_unlock; - -out_del: - del_symlink(disk->slave_dir, bdev_kobj(bdev)); -out_free: - kfree(holder); -out_unlock: - mutex_unlock(&bdev->bd_disk->open_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(bd_link_disk_holder); - -/** - * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() - * @bdev: the calimed slave bdev - * @disk: the holding disk - * - * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. - * - * CONTEXT: - * Might sleep. - */ -void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) -{ - struct bd_holder_disk *holder; - - mutex_lock(&bdev->bd_disk->open_mutex); - - holder = bd_find_holder_disk(bdev, disk); - - if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { - del_symlink(disk->slave_dir, bdev_kobj(bdev)); - del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); - kobject_put(bdev->bd_holder_dir); - list_del_init(&holder->list); - kfree(holder); - } - - mutex_unlock(&bdev->bd_disk->open_mutex); -} -EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); -#endif - static void blkdev_flush_mapping(struct block_device *bdev) { WARN_ON_ONCE(bdev->bd_holders); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 290f9061b29a..7a4e139d24ef 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -34,7 +34,7 @@ struct block_device { void * bd_holder; int bd_holders; bool bd_write_holder; -#ifdef CONFIG_SYSFS +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED struct list_head bd_holder_disks; #endif struct kobject *bd_holder_dir; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 849486de81c6..e21a91c16a79 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -318,7 +318,7 @@ void set_capacity(struct gendisk *disk, sector_t size); int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long); long compat_blkdev_ioctl(struct file *, unsigned, unsigned long); -#ifdef CONFIG_SYSFS +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk); void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk); #else @@ -331,7 +331,7 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) { } -#endif /* CONFIG_SYSFS */ +#endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */ dev_t part_devt(struct gendisk *disk, u8 partno); void inc_diskseq(struct gendisk *disk); -- 2.30.2 -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel
next prev parent reply other threads:[~2021-08-04 9:43 UTC|newest] Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-04 9:41 use regular gendisk registration in device mapper v2 Christoph Hellwig 2021-08-04 9:41 ` [dm-devel] " Christoph Hellwig 2021-08-04 9:41 ` Christoph Hellwig [this message] 2021-08-04 9:41 ` [dm-devel] [PATCH 1/8] block: make the block holder code optional Christoph Hellwig 2021-08-04 9:41 ` [PATCH 2/8] block: remove the extra kobject reference in bd_link_disk_holder Christoph Hellwig 2021-08-04 9:41 ` [dm-devel] " Christoph Hellwig 2021-08-04 9:41 ` [PATCH 3/8] block: look up holders by bdev Christoph Hellwig 2021-08-04 9:41 ` [dm-devel] " Christoph Hellwig 2021-08-04 9:41 ` [PATCH 4/8] block: support delayed holder registration Christoph Hellwig 2021-08-04 9:41 ` [dm-devel] " Christoph Hellwig [not found] ` <CGME20210810213058eucas1p109323e3c3ecaa76d37d8cf63b6d8ecfd@eucas1p1.samsung.com> 2021-08-10 21:30 ` Marek Szyprowski 2021-08-10 21:30 ` [dm-devel] " Marek Szyprowski 2021-08-14 21:13 ` Guenter Roeck 2021-08-14 21:13 ` Guenter Roeck 2021-08-15 7:07 ` Christoph Hellwig 2021-08-15 7:07 ` Christoph Hellwig 2021-08-15 14:27 ` Guenter Roeck 2021-08-15 14:27 ` Guenter Roeck 2021-08-16 7:21 ` Christoph Hellwig 2021-08-16 7:21 ` Christoph Hellwig 2021-08-16 14:17 ` Guenter Roeck 2021-08-16 14:17 ` Guenter Roeck 2021-08-20 15:08 ` Christoph Hellwig 2021-08-20 15:08 ` Christoph Hellwig 2021-08-21 3:17 ` Guenter Roeck 2021-08-21 3:17 ` Guenter Roeck 2021-08-18 2:51 ` Guenter Roeck 2021-08-18 2:51 ` Guenter Roeck 2021-08-04 9:41 ` [PATCH 5/8] dm: cleanup cleanup_mapped_device Christoph Hellwig 2021-08-04 9:41 ` [dm-devel] " Christoph Hellwig 2021-08-04 9:41 ` [PATCH 6/8] dm: move setting md->type into dm_setup_md_queue Christoph Hellwig 2021-08-04 9:41 ` [dm-devel] " Christoph Hellwig 2021-08-04 9:41 ` [PATCH 7/8] dm: delay registering the gendisk Christoph Hellwig 2021-08-04 9:41 ` [dm-devel] " Christoph Hellwig 2021-08-09 23:31 ` Alasdair G Kergon 2021-08-09 23:31 ` Alasdair G Kergon 2021-08-10 0:17 ` Alasdair G Kergon 2021-08-10 0:17 ` Alasdair G Kergon 2021-08-10 13:12 ` Peter Rajnoha 2021-08-10 13:12 ` Peter Rajnoha 2021-08-10 15:05 ` Alasdair G Kergon 2021-08-10 15:05 ` Alasdair G Kergon 2022-07-07 3:29 ` Yu Kuai 2022-07-07 3:29 ` [dm-devel] " Yu Kuai 2022-07-07 5:24 ` Christoph Hellwig 2022-07-07 5:24 ` [dm-devel] " Christoph Hellwig 2022-07-07 7:20 ` Yu Kuai 2022-07-07 7:20 ` [dm-devel] " Yu Kuai 2022-07-15 3:24 ` Yu Kuai 2022-07-15 3:24 ` [dm-devel] " Yu Kuai 2022-08-01 1:04 ` Yu Kuai 2022-08-01 1:04 ` [dm-devel] " Yu Kuai 2021-08-04 9:41 ` [PATCH 8/8] block: remove support for delayed queue registrations Christoph Hellwig 2021-08-04 9:41 ` [dm-devel] " Christoph Hellwig 2021-08-09 17:51 ` use regular gendisk registration in device mapper v2 Jens Axboe 2021-08-09 17:51 ` [dm-devel] " Jens Axboe 2021-08-10 0:36 ` Alasdair G Kergon 2021-08-10 0:36 ` Alasdair G Kergon 2021-08-10 14:41 ` Alasdair G Kergon 2021-08-10 14:41 ` Alasdair G Kergon 2021-08-19 15:58 ` holders not working properly, regression [was: Re: use regular gendisk registration in device mapper v2] Mike Snitzer 2021-08-19 15:58 ` [dm-devel] " Mike Snitzer 2021-08-19 18:05 ` Christoph Hellwig 2021-08-19 18:05 ` [dm-devel] " Christoph Hellwig 2021-08-19 22:08 ` Mike Snitzer 2021-08-19 22:08 ` [dm-devel] " Mike Snitzer -- strict thread matches above, loose matches on Subject: below -- 2021-07-25 5:54 use regular gendisk registration in device mapper Christoph Hellwig 2021-07-25 5:54 ` [PATCH 1/8] block: make the block holder code optional Christoph Hellwig 2021-07-29 16:25 ` Mike Snitzer
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