From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-bcache@vger.kernel.org, Jan Kara <jack@suse.cz>,
linux-fsdevel@vger.kernel.org, Mike Snitzer <snitzer@redhat.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jan Kara <jack@suse.com>, Josef Bacik <josef@toxicpanda.com>,
Coly Li <colyli@suse.de>,
linux-block@vger.kernel.org, Richard Weinberger <richard@nod.at>,
dm-devel@redhat.com, linux-mtd@lists.infradead.org,
Johannes Thumshirn <johannes.thumshirn@wdc.com>,
Tejun Heo <tj@kernel.org>,
xen-devel@lists.xenproject.org, linux-mm@kvack.org
Subject: [dm-devel] [PATCH 06/45] zram: remove the claim mechanism
Date: Tue, 24 Nov 2020 14:27:12 +0100 [thread overview]
Message-ID: <20201124132751.3747337-7-hch@lst.de> (raw)
In-Reply-To: <20201124132751.3747337-1-hch@lst.de>
The zram claim mechanism was added to ensure no new opens come in
during teardown. But the proper way to archive that is to call
del_gendisk first, which takes care of all that. Once del_gendisk
is called in the right place, the reset side can also be simplified
as no I/O can be outstanding on a block device that is not open.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/block/zram/zram_drv.c | 72 ++++++++---------------------------
1 file changed, 15 insertions(+), 57 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 6d15d51cee2b7e..2e6d75ec1afddb 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1756,64 +1756,33 @@ static ssize_t disksize_store(struct device *dev,
static ssize_t reset_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
- int ret;
- unsigned short do_reset;
- struct zram *zram;
+ struct zram *zram = dev_to_zram(dev);
struct block_device *bdev;
+ unsigned short do_reset;
+ int ret = 0;
ret = kstrtou16(buf, 10, &do_reset);
if (ret)
return ret;
-
if (!do_reset)
return -EINVAL;
- zram = dev_to_zram(dev);
bdev = bdget_disk(zram->disk, 0);
if (!bdev)
return -ENOMEM;
mutex_lock(&bdev->bd_mutex);
- /* Do not reset an active device or claimed device */
- if (bdev->bd_openers || zram->claim) {
- mutex_unlock(&bdev->bd_mutex);
- bdput(bdev);
- return -EBUSY;
- }
-
- /* From now on, anyone can't open /dev/zram[0-9] */
- zram->claim = true;
+ if (bdev->bd_openers)
+ ret = -EBUSY;
+ else
+ zram_reset_device(zram);
mutex_unlock(&bdev->bd_mutex);
-
- /* Make sure all the pending I/O are finished */
- fsync_bdev(bdev);
- zram_reset_device(zram);
bdput(bdev);
- mutex_lock(&bdev->bd_mutex);
- zram->claim = false;
- mutex_unlock(&bdev->bd_mutex);
-
- return len;
-}
-
-static int zram_open(struct block_device *bdev, fmode_t mode)
-{
- int ret = 0;
- struct zram *zram;
-
- WARN_ON(!mutex_is_locked(&bdev->bd_mutex));
-
- zram = bdev->bd_disk->private_data;
- /* zram was claimed to reset so open request fails */
- if (zram->claim)
- ret = -EBUSY;
-
- return ret;
+ return ret ? ret : len;
}
static const struct block_device_operations zram_devops = {
- .open = zram_open,
.submit_bio = zram_submit_bio,
.swap_slot_free_notify = zram_slot_free_notify,
.rw_page = zram_rw_page,
@@ -1821,7 +1790,6 @@ static const struct block_device_operations zram_devops = {
};
static const struct block_device_operations zram_wb_devops = {
- .open = zram_open,
.submit_bio = zram_submit_bio,
.swap_slot_free_notify = zram_slot_free_notify,
.owner = THIS_MODULE
@@ -1974,32 +1942,22 @@ static int zram_add(void)
static int zram_remove(struct zram *zram)
{
- struct block_device *bdev;
-
- bdev = bdget_disk(zram->disk, 0);
- if (!bdev)
- return -ENOMEM;
+ struct block_device *bdev = bdget_disk(zram->disk, 0);
- mutex_lock(&bdev->bd_mutex);
- if (bdev->bd_openers || zram->claim) {
- mutex_unlock(&bdev->bd_mutex);
+ if (bdev) {
+ if (bdev->bd_openers) {
+ bdput(bdev);
+ return -EBUSY;
+ }
bdput(bdev);
- return -EBUSY;
}
- zram->claim = true;
- mutex_unlock(&bdev->bd_mutex);
-
+ del_gendisk(zram->disk);
zram_debugfs_unregister(zram);
-
- /* Make sure all the pending I/O are finished */
- fsync_bdev(bdev);
zram_reset_device(zram);
- bdput(bdev);
pr_info("Removed device: %s\n", zram->disk->disk_name);
- del_gendisk(zram->disk);
blk_cleanup_queue(zram->disk->queue);
put_disk(zram->disk);
kfree(zram);
--
2.29.2
--
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next prev parent reply other threads:[~2020-11-24 13:32 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-24 13:27 [dm-devel] merge struct block_device and struct hd_struct v2 Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 01/45] blk-cgroup: fix a hd_struct leak in blkcg_fill_root_iostats Christoph Hellwig
2020-11-25 6:41 ` Hannes Reinecke
2020-11-24 13:27 ` [dm-devel] [PATCH 02/45] filemap: consistently use ->f_mapping over ->i_mapping Christoph Hellwig
2020-11-24 13:53 ` Matthew Wilcox
2020-11-25 6:41 ` Hannes Reinecke
2020-11-25 12:16 ` Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 03/45] fs: remove get_super_thawed and get_super_exclusive_thawed Christoph Hellwig
2020-11-25 6:42 ` Hannes Reinecke
2020-11-25 12:19 ` Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 04/45] fs: simplify freeze_bdev/thaw_bdev Christoph Hellwig
2020-11-25 6:07 ` Chao Yu
2020-11-25 12:29 ` Jan Kara
2020-11-25 16:22 ` Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 05/45] mtip32xx: remove the call to fsync_bdev on removal Christoph Hellwig
2020-11-25 12:31 ` Jan Kara
2020-11-24 13:27 ` Christoph Hellwig [this message]
2020-11-25 12:37 ` [dm-devel] [PATCH 06/45] zram: remove the claim mechanism Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 07/45] zram: do not call set_blocksize Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 08/45] loop: " Christoph Hellwig
2020-11-25 13:37 ` Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 09/45] dm: simplify flush_bio initialization in __send_empty_flush Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 10/45] dm: remove the block_device reference in struct mapped_device Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 11/45] block: remove a duplicate __disk_get_part prototype Christoph Hellwig
2020-11-24 17:36 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 12/45] block: remove a superflous check in blkpg_do_ioctl Christoph Hellwig
2020-11-24 17:37 ` Tejun Heo
2020-11-25 13:39 ` Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 13/45] block: add a bdev_kobj helper Christoph Hellwig
2020-11-24 13:41 ` Coly Li
2020-11-24 17:37 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 14/45] block: use disk_part_iter_exit in disk_part_iter_next Christoph Hellwig
2020-11-24 17:37 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 15/45] block: use put_device in put_disk Christoph Hellwig
2020-11-24 17:37 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 16/45] block: change the hash used for looking up block devices Christoph Hellwig
2020-11-24 17:38 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 17/45] init: refactor name_to_dev_t Christoph Hellwig
2020-11-24 17:38 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 18/45] init: refactor devt_from_partuuid Christoph Hellwig
2020-11-24 17:38 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 19/45] init: cleanup match_dev_by_uuid and match_dev_by_label Christoph Hellwig
2020-11-24 17:39 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 20/45] block: refactor __blkdev_put Christoph Hellwig
2020-11-24 17:41 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 21/45] block: refactor blkdev_get Christoph Hellwig
2020-11-24 18:03 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 22/45] block: opencode devcgroup_inode_permission Christoph Hellwig
2020-11-24 18:05 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 23/45] block: remove i_bdev Christoph Hellwig
2020-11-24 13:38 ` Coly Li
2020-11-24 19:37 ` Tejun Heo
2020-11-25 16:29 ` Christoph Hellwig
2020-11-25 20:19 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 24/45] blk-cgroup: stop abusing get_gendisk Christoph Hellwig
2020-11-24 19:46 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 25/45] block: reference struct block_device from struct hd_struct Christoph Hellwig
2020-11-24 21:18 ` Tejun Heo
2020-11-25 16:45 ` Christoph Hellwig
2020-11-25 20:20 ` Tejun Heo
2020-11-26 8:16 ` Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 26/45] block: remove ->bd_contains Christoph Hellwig
2020-11-24 21:19 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 27/45] block: simplify the block device claiming interface Christoph Hellwig
2020-11-24 21:19 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 28/45] block: simplify part_to_disk Christoph Hellwig
2020-11-24 21:20 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 29/45] block: initialize struct block_device in bdev_alloc Christoph Hellwig
2020-11-24 21:20 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 30/45] block: remove the nr_sects field in struct hd_struct Christoph Hellwig
2020-11-24 13:34 ` Coly Li
2020-11-25 6:10 ` Chao Yu
2020-11-24 13:27 ` [dm-devel] [PATCH 31/45] block: move disk stat accounting to struct block_device Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 32/45] block: move the start_sect field " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 33/45] block: move the partition_meta_info " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 34/45] block: move holder_dir " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 35/45] block: move make_it_fail " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 36/45] block: move the policy field " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 37/45] block: allocate struct hd_struct as part of struct bdev_inode Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 38/45] block: switch partition lookup to use struct block_device Christoph Hellwig
2020-11-24 13:32 ` Coly Li
2020-11-25 6:11 ` Chao Yu
2020-11-24 13:27 ` [dm-devel] [PATCH 39/45] block: remove the partno field from struct hd_struct Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 40/45] block: pass a block_device to blk_alloc_devt Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 41/45] block: pass a block_device to invalidate_partition Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 42/45] block: switch disk_part_iter_* to use a struct block_device Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 43/45] f2fs: remove a few bd_part checks Christoph Hellwig
2020-11-25 6:12 ` Chao Yu
2020-11-24 13:27 ` [dm-devel] [PATCH 44/45] block: merge struct block_device and struct hd_struct Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 45/45] block: stop using bdget_disk for partition 0 Christoph Hellwig
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