On Wed 18-11-20 09:47:52, Christoph Hellwig wrote:
> Stop passing the whole device as a separate argument given that it
> can be trivially deducted.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
The patch looks good to me. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> drivers/block/loop.c | 12 +++-----
> fs/block_dev.c | 69 +++++++++++++++++++-----------------------
> include/linux/blkdev.h | 6 ++--
> 3 files changed, 38 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index b42c728620c9e4..599e94a7e69259 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -1071,7 +1071,6 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
> struct file *file;
> struct inode *inode;
> struct address_space *mapping;
> - struct block_device *claimed_bdev = NULL;
> int error;
> loff_t size;
> bool partscan;
> @@ -1090,8 +1089,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
> * here to avoid changing device under exclusive owner.
> */
> if (!(mode & FMODE_EXCL)) {
> - claimed_bdev = bdev->bd_contains;
> - error = bd_prepare_to_claim(bdev, claimed_bdev, loop_configure);
> + error = bd_prepare_to_claim(bdev, loop_configure);
> if (error)
> goto out_putf;
> }
> @@ -1178,15 +1176,15 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
> mutex_unlock(&loop_ctl_mutex);
> if (partscan)
> loop_reread_partitions(lo, bdev);
> - if (claimed_bdev)
> - bd_abort_claiming(bdev, claimed_bdev, loop_configure);
> + if (!(mode & FMODE_EXCL))
> + bd_abort_claiming(bdev, loop_configure);
> return 0;
>
> out_unlock:
> mutex_unlock(&loop_ctl_mutex);
> out_bdev:
> - if (claimed_bdev)
> - bd_abort_claiming(bdev, claimed_bdev, loop_configure);
> + if (!(mode & FMODE_EXCL))
> + bd_abort_claiming(bdev, loop_configure);
> out_putf:
> fput(file);
> out:
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index e94633dc6ad93b..dd52dbd266cde7 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -110,24 +110,20 @@ EXPORT_SYMBOL(invalidate_bdev);
> int truncate_bdev_range(struct block_device *bdev, fmode_t mode,
> loff_t lstart, loff_t lend)
> {
> - struct block_device *claimed_bdev = NULL;
> - int err;
> -
> /*
> * If we don't hold exclusive handle for the device, upgrade to it
> * while we discard the buffer cache to avoid discarding buffers
> * under live filesystem.
> */
> if (!(mode & FMODE_EXCL)) {
> - claimed_bdev = bdev->bd_contains;
> - err = bd_prepare_to_claim(bdev, claimed_bdev,
> - truncate_bdev_range);
> + int err = bd_prepare_to_claim(bdev, truncate_bdev_range);
> if (err)
> return err;
> }
> +
> truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend);
> - if (claimed_bdev)
> - bd_abort_claiming(bdev, claimed_bdev, truncate_bdev_range);
> + if (!(mode & FMODE_EXCL))
> + bd_abort_claiming(bdev, truncate_bdev_range);
> return 0;
> }
> EXPORT_SYMBOL(truncate_bdev_range);
> @@ -1047,7 +1043,6 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole,
> /**
> * bd_prepare_to_claim - claim a block device
> * @bdev: block device of interest
> - * @whole: the whole device containing @bdev, may equal @bdev
> * @holder: holder trying to claim @bdev
> *
> * Claim @bdev. This function fails if @bdev is already claimed by another
> @@ -1057,9 +1052,10 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole,
> * RETURNS:
> * 0 if @bdev can be claimed, -EBUSY otherwise.
> */
> -int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole,
> - void *holder)
> +int bd_prepare_to_claim(struct block_device *bdev, void *holder)
> {
> + struct block_device *whole = bdev->bd_contains;
> +
> retry:
> spin_lock(&bdev_lock);
> /* if someone else claimed, fail */
> @@ -1099,15 +1095,15 @@ static void bd_clear_claiming(struct block_device *whole, void *holder)
> /**
> * bd_finish_claiming - finish claiming of a block device
> * @bdev: block device of interest
> - * @whole: whole block device
> * @holder: holder that has claimed @bdev
> *
> * Finish exclusive open of a block device. Mark the device as exlusively
> * open by the holder and wake up all waiters for exclusive open to finish.
> */
> -static void bd_finish_claiming(struct block_device *bdev,
> - struct block_device *whole, void *holder)
> +static void bd_finish_claiming(struct block_device *bdev, void *holder)
> {
> + struct block_device *whole = bdev->bd_contains;
> +
> spin_lock(&bdev_lock);
> BUG_ON(!bd_may_claim(bdev, whole, holder));
> /*
> @@ -1132,11 +1128,10 @@ static void bd_finish_claiming(struct block_device *bdev,
> * also used when exclusive open is not actually desired and we just needed
> * to block other exclusive openers for a while.
> */
> -void bd_abort_claiming(struct block_device *bdev, struct block_device *whole,
> - void *holder)
> +void bd_abort_claiming(struct block_device *bdev, void *holder)
> {
> spin_lock(&bdev_lock);
> - bd_clear_claiming(whole, holder);
> + bd_clear_claiming(bdev->bd_contains, holder);
> spin_unlock(&bdev_lock);
> }
> EXPORT_SYMBOL(bd_abort_claiming);
> @@ -1434,7 +1429,7 @@ static void put_disk_and_module(struct gendisk *disk)
> static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
> int for_part)
> {
> - struct block_device *whole = NULL, *claiming = NULL;
> + struct block_device *whole = NULL;
> struct gendisk *disk = bdev->bd_disk;
> int ret;
> bool first_open = false, unblock_events = true, need_restart;
> @@ -1462,11 +1457,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
>
> if (!for_part && (mode & FMODE_EXCL)) {
> WARN_ON_ONCE(!holder);
> - if (whole)
> - claiming = whole;
> - else
> - claiming = bdev;
> - ret = bd_prepare_to_claim(bdev, claiming, holder);
> + ret = bd_prepare_to_claim(bdev, holder);
> if (ret)
> goto out_put_whole;
> }
> @@ -1543,21 +1534,23 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
> }
> }
> bdev->bd_openers++;
> - if (for_part)
> + if (for_part) {
> bdev->bd_part_count++;
> - if (claiming)
> - bd_finish_claiming(bdev, claiming, holder);
> + } else if (mode & FMODE_EXCL) {
> + bd_finish_claiming(bdev, holder);
>
> - /*
> - * Block event polling for write claims if requested. Any write holder
> - * makes the write_holder state stick until all are released. This is
> - * good enough and tracking individual writeable reference is too
> - * fragile given the way @mode is used in blkdev_get/put().
> - */
> - if (claiming && (mode & FMODE_WRITE) && !bdev->bd_write_holder &&
> - (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
> - bdev->bd_write_holder = true;
> - unblock_events = false;
> + /*
> + * Block event polling for write claims if requested. Any write
> + * holder makes the write_holder state stick until all are
> + * released. This is good enough and tracking individual
> + * writeable reference is too fragile given the way @mode is
> + * used in blkdev_get/put().
> + */
> + if ((mode & FMODE_WRITE) && !bdev->bd_write_holder &&
> + (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
> + bdev->bd_write_holder = true;
> + unblock_events = false;
> + }
> }
> mutex_unlock(&bdev->bd_mutex);
>
> @@ -1578,8 +1571,8 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
> __blkdev_put(bdev->bd_contains, mode, 1);
> bdev->bd_contains = NULL;
> out_unlock_bdev:
> - if (claiming)
> - bd_abort_claiming(bdev, claiming, holder);
> + if (!for_part && (mode & FMODE_EXCL))
> + bd_abort_claiming(bdev, holder);
> mutex_unlock(&bdev->bd_mutex);
> disk_unblock_events(disk);
> out_put_whole:
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 044d9dd159d882..696b2f9c5529d8 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -1988,10 +1988,8 @@ void blkdev_show(struct seq_file *seqf, off_t offset);
> struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
> void *holder);
> struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder);
> -int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole,
> - void *holder);
> -void bd_abort_claiming(struct block_device *bdev, struct block_device *whole,
> - void *holder);
> +int bd_prepare_to_claim(struct block_device *bdev, void *holder);
> +void bd_abort_claiming(struct block_device *bdev, void *holder);
> void blkdev_put(struct block_device *bdev, fmode_t mode);
>
> struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
> --
> 2.29.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
