From d666e20e2e7983d03bbf5e208b8485541ae616a1 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 30 Mar 2022 07:29:04 +0200 Subject: zram: cleanup reset_store Use a local variable for the gendisk instead of the part0 block_device, as the gendisk is what this function actually operates on. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220330052917.2566582-3-hch@lst.de Signed-off-by: Jens Axboe --- drivers/block/zram/zram_drv.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/block/zram') diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 59ff444bf6c7..387d8697d700 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1786,7 +1786,7 @@ static ssize_t reset_store(struct device *dev, int ret; unsigned short do_reset; struct zram *zram; - struct block_device *bdev; + struct gendisk *disk; ret = kstrtou16(buf, 10, &do_reset); if (ret) @@ -1796,26 +1796,26 @@ static ssize_t reset_store(struct device *dev, return -EINVAL; zram = dev_to_zram(dev); - bdev = zram->disk->part0; + disk = zram->disk; - mutex_lock(&bdev->bd_disk->open_mutex); + mutex_lock(&disk->open_mutex); /* Do not reset an active device or claimed device */ - if (bdev->bd_openers || zram->claim) { - mutex_unlock(&bdev->bd_disk->open_mutex); + if (disk->part0->bd_openers || zram->claim) { + mutex_unlock(&disk->open_mutex); return -EBUSY; } /* From now on, anyone can't open /dev/zram[0-9] */ zram->claim = true; - mutex_unlock(&bdev->bd_disk->open_mutex); + mutex_unlock(&disk->open_mutex); /* Make sure all the pending I/O are finished */ - sync_blockdev(bdev); + sync_blockdev(disk->part0); zram_reset_device(zram); - mutex_lock(&bdev->bd_disk->open_mutex); + mutex_lock(&disk->open_mutex); zram->claim = false; - mutex_unlock(&bdev->bd_disk->open_mutex); + mutex_unlock(&disk->open_mutex); return len; } -- cgit From 7a86d6dc1493326feb0d3ce5af2f34401dd3defa Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 30 Mar 2022 07:29:05 +0200 Subject: zram: cleanup zram_remove Remove the bdev variable and just use the gendisk pointed to by the zram_device directly. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220330052917.2566582-4-hch@lst.de Signed-off-by: Jens Axboe --- drivers/block/zram/zram_drv.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'drivers/block/zram') diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 387d8697d700..70d4bd662ab6 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1986,19 +1986,18 @@ out_free_dev: static int zram_remove(struct zram *zram) { - struct block_device *bdev = zram->disk->part0; bool claimed; - mutex_lock(&bdev->bd_disk->open_mutex); - if (bdev->bd_openers) { - mutex_unlock(&bdev->bd_disk->open_mutex); + mutex_lock(&zram->disk->open_mutex); + if (zram->disk->part0->bd_openers) { + mutex_unlock(&zram->disk->open_mutex); return -EBUSY; } claimed = zram->claim; if (!claimed) zram->claim = true; - mutex_unlock(&bdev->bd_disk->open_mutex); + mutex_unlock(&zram->disk->open_mutex); zram_debugfs_unregister(zram); @@ -2010,7 +2009,7 @@ static int zram_remove(struct zram *zram) ; } else { /* Make sure all the pending I/O are finished */ - sync_blockdev(bdev); + sync_blockdev(zram->disk->part0); zram_reset_device(zram); } -- cgit From dbdc1be32591af023db2812706f01e6cd2f42bfc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 30 Mar 2022 07:29:06 +0200 Subject: block: add a disk_openers helper Add a helper that returns the openers for a given gendisk to avoid having drivers poke into disk->part0 to get at this information in a somewhat cumbersome way. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220330052917.2566582-5-hch@lst.de Signed-off-by: Jens Axboe --- drivers/block/nbd.c | 4 ++-- drivers/block/zram/zram_drv.c | 4 ++-- include/linux/blkdev.h | 15 +++++++++++++++ 3 files changed, 19 insertions(+), 4 deletions(-) (limited to 'drivers/block/zram') diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index dab24c58d5cc..526389351784 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1219,7 +1219,7 @@ static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg) static void nbd_bdev_reset(struct nbd_device *nbd) { - if (nbd->disk->part0->bd_openers > 1) + if (disk_openers(nbd->disk) > 1) return; set_capacity(nbd->disk, 0); } @@ -1576,7 +1576,7 @@ static void nbd_release(struct gendisk *disk, fmode_t mode) struct nbd_device *nbd = disk->private_data; if (test_bit(NBD_RT_DISCONNECT_ON_CLOSE, &nbd->config->runtime_flags) && - disk->part0->bd_openers == 0) + disk_openers(disk) == 0) nbd_disconnect_and_put(nbd); nbd_config_put(nbd); diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 70d4bd662ab6..dc5ac5963377 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1800,7 +1800,7 @@ static ssize_t reset_store(struct device *dev, mutex_lock(&disk->open_mutex); /* Do not reset an active device or claimed device */ - if (disk->part0->bd_openers || zram->claim) { + if (disk_openers(disk) || zram->claim) { mutex_unlock(&disk->open_mutex); return -EBUSY; } @@ -1989,7 +1989,7 @@ static int zram_remove(struct zram *zram) bool claimed; mutex_lock(&zram->disk->open_mutex); - if (zram->disk->part0->bd_openers) { + if (disk_openers(zram->disk)) { mutex_unlock(&zram->disk->open_mutex); return -EBUSY; } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c9b5925af5a3..436645bde13f 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -176,6 +176,21 @@ static inline bool disk_live(struct gendisk *disk) return !inode_unhashed(disk->part0->bd_inode); } +/** + * disk_openers - returns how many openers are there for a disk + * @disk: disk to check + * + * This returns the number of openers for a disk. Note that this value is only + * stable if disk->open_mutex is held. + * + * Note: Due to a quirk in the block layer open code, each open partition is + * only counted once even if there are multiple openers. + */ +static inline unsigned int disk_openers(struct gendisk *disk) +{ + return disk->part0->bd_openers; +} + /* * The gendisk is refcounted by the part0 block_device, and the bd_device * therein is also used for device model presentation in sysfs. -- cgit