Add support for persistent reservations. Effectively all that is done here is that a multipath version of pr_ops is created which calls into the bdev fops callback for the mpath_device selected.
Signed-off-by: John Garry <[email protected]> --- include/linux/multipath.h | 1 + lib/multipath.c | 182 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 183 insertions(+) diff --git a/include/linux/multipath.h b/include/linux/multipath.h index b18491c1d077f..7464c94fbcc3e 100644 --- a/include/linux/multipath.h +++ b/include/linux/multipath.h @@ -5,6 +5,7 @@ #include <linux/blkdev.h> #include <linux/blk-mq.h> #include <linux/cdev.h> +#include <linux/pr.h> #include <linux/srcu.h> #include <linux/io_uring/cmd.h> diff --git a/lib/multipath.c b/lib/multipath.c index 680bb4f0ae237..d2270c70b9913 100644 --- a/lib/multipath.c +++ b/lib/multipath.c @@ -466,11 +466,193 @@ static void mpath_bdev_release(struct gendisk *disk) mpath_put_head(mpath_head); } +static int mpath_pr_register(struct block_device *bdev, u64 old_key, + u64 new_key, unsigned int flags) +{ + struct mpath_head *mpath_head = dev_get_drvdata(&bdev->bd_device); + struct mpath_device *mpath_device; + int srcu_idx, ret = -EWOULDBLOCK; + + srcu_idx = srcu_read_lock(&mpath_head->srcu); + mpath_device = mpath_find_path(mpath_head); + if (mpath_device) { + const struct pr_ops *ops = mpath_device->disk->fops->pr_ops; + + if (!ops || !ops->pr_register) { + ret = -EOPNOTSUPP; + goto unlock; + } + ret = ops->pr_register(mpath_device->disk->part0, + old_key, new_key, flags); + } +unlock: + srcu_read_unlock(&mpath_head->srcu, srcu_idx); + + return ret; +} + +static int mpath_pr_reserve(struct block_device *bdev, u64 key, + enum pr_type type, unsigned flags) +{ + struct mpath_head *mpath_head = dev_get_drvdata(&bdev->bd_device); + struct mpath_device *mpath_device; + int srcu_idx, ret = -EWOULDBLOCK; + + srcu_idx = srcu_read_lock(&mpath_head->srcu); + mpath_device = mpath_find_path(mpath_head); + if (mpath_device) { + const struct pr_ops *ops = mpath_device->disk->fops->pr_ops; + + if (!ops || !ops->pr_reserve) { + ret = -EOPNOTSUPP; + goto unlock; + } + ret = ops->pr_reserve(mpath_device->disk->part0, key, + type, flags); + } +unlock: + srcu_read_unlock(&mpath_head->srcu, srcu_idx); + + return ret; +} + +static int mpath_pr_release(struct block_device *bdev, u64 key, + enum pr_type type) +{ + struct mpath_head *mpath_head = dev_get_drvdata(&bdev->bd_device); + struct mpath_device *mpath_device; + int srcu_idx, ret = -EWOULDBLOCK; + + srcu_idx = srcu_read_lock(&mpath_head->srcu); + mpath_device = mpath_find_path(mpath_head); + if (mpath_device) { + const struct pr_ops *ops = mpath_device->disk->fops->pr_ops; + + if (!ops || !ops->pr_release) { + ret = -EOPNOTSUPP; + goto unlock; + } + ret = ops->pr_release(mpath_device->disk->part0, key, type); + } +unlock: + srcu_read_unlock(&mpath_head->srcu, srcu_idx); + + return ret; +} + +static int mpath_pr_preempt(struct block_device *bdev, u64 old, u64 new, + enum pr_type type, bool abort) +{ + struct mpath_head *mpath_head = dev_get_drvdata(&bdev->bd_device); + struct mpath_device *mpath_device; + int srcu_idx, ret = -EWOULDBLOCK; + + srcu_idx = srcu_read_lock(&mpath_head->srcu); + mpath_device = mpath_find_path(mpath_head); + if (mpath_device) { + const struct pr_ops *ops = mpath_device->disk->fops->pr_ops; + + if (!ops || !ops->pr_preempt) { + ret = -EOPNOTSUPP; + goto unlock; + } + ret = ops->pr_preempt(mpath_device->disk->part0, old, + new, type, abort); + } +unlock: + srcu_read_unlock(&mpath_head->srcu, srcu_idx); + + return ret; +} + +static int mpath_pr_clear(struct block_device *bdev, u64 key) +{ + struct mpath_head *mpath_head = dev_get_drvdata(&bdev->bd_device); + struct mpath_device *mpath_device; + int srcu_idx, ret = -EWOULDBLOCK; + + srcu_idx = srcu_read_lock(&mpath_head->srcu); + mpath_device = mpath_find_path(mpath_head); + if (mpath_device) { + const struct pr_ops *ops = mpath_device->disk->fops->pr_ops; + + if (!ops || !ops->pr_clear) { + ret = -EOPNOTSUPP; + goto unlock; + } + ret = ops->pr_clear(mpath_device->disk->part0, key); + } +unlock: + srcu_read_unlock(&mpath_head->srcu, srcu_idx); + + return ret; +} + +static int mpath_pr_read_keys(struct block_device *bdev, + struct pr_keys *keys_info) +{ + struct mpath_head *mpath_head = dev_get_drvdata(&bdev->bd_device); + struct mpath_device *mpath_device; + int srcu_idx, ret = -EWOULDBLOCK; + + srcu_idx = srcu_read_lock(&mpath_head->srcu); + mpath_device = mpath_find_path(mpath_head); + if (mpath_device) { + const struct pr_ops *ops = mpath_device->disk->fops->pr_ops; + + if (!ops || !ops->pr_read_keys) { + ret = -EOPNOTSUPP; + goto unlock; + } + ret = ops->pr_read_keys(mpath_device->disk->part0, keys_info); + } +unlock: + srcu_read_unlock(&mpath_head->srcu, srcu_idx); + + return ret; +} + +static int mpath_pr_read_reservation(struct block_device *bdev, + struct pr_held_reservation *resv) +{ + struct mpath_head *mpath_head = dev_get_drvdata(&bdev->bd_device); + struct mpath_device *mpath_device; + int srcu_idx, ret = -EWOULDBLOCK; + + srcu_idx = srcu_read_lock(&mpath_head->srcu); + mpath_device = mpath_find_path(mpath_head); + if (mpath_device) { + const struct pr_ops *ops = mpath_device->disk->fops->pr_ops; + + if (!ops || !ops->pr_read_reservation) { + ret = -EOPNOTSUPP; + goto unlock; + } + ret = ops->pr_read_reservation(mpath_device->disk->part0, + resv); + } +unlock: + srcu_read_unlock(&mpath_head->srcu, srcu_idx); + + return ret; +} + +static const struct pr_ops mpath_pr_ops = { + .pr_register = mpath_pr_register, + .pr_reserve = mpath_pr_reserve, + .pr_release = mpath_pr_release, + .pr_preempt = mpath_pr_preempt, + .pr_clear = mpath_pr_clear, + .pr_read_keys = mpath_pr_read_keys, + .pr_read_reservation = mpath_pr_read_reservation, +}; + const struct block_device_operations mpath_ops = { .owner = THIS_MODULE, .open = mpath_bdev_open, .release = mpath_bdev_release, .submit_bio = mpath_bdev_submit_bio, + .pr_ops = &mpath_pr_ops, }; EXPORT_SYMBOL_GPL(mpath_ops); -- 2.43.5
