From: Hannes Reinecke <hare@suse.de>
To: Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>
Cc: linux-bcache@vger.kernel.org, Jan Kara <jack@suse.cz>,
Mike Snitzer <snitzer@redhat.com>,
linux-mm@kvack.org,
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, linux-fsdevel@vger.kernel.org,
dm-devel@redhat.com, linux-mtd@lists.infradead.org,
Johannes Thumshirn <johannes.thumshirn@wdc.com>,
Tejun Heo <tj@kernel.org>
Subject: Re: [dm-devel] [PATCH 25/45] block: simplify bdev/disk lookup in blkdev_get
Date: Mon, 30 Nov 2020 08:36:19 +0100 [thread overview]
Message-ID: <daa050e6-8758-a458-91fe-046c5690a336@suse.de> (raw)
In-Reply-To: <20201128161510.347752-26-hch@lst.de>
On 11/28/20 5:14 PM, Christoph Hellwig wrote:
> To simplify block device lookup and a few other upcoming areas, make sure
> that we always have a struct block_device available for each disk and
> each partition, and only find existing block devices in bdget. The only
> downside of this is that each device and partition uses a little more
> memory. The upside will be that a lot of code can be simplified.
>
> With that all we need to look up the block device is to lookup the inode
> and do a few sanity checks on the gendisk, instead of the separate lookup
> for the gendisk. For blk-cgroup which wants to access a gendisk without
> opening it, a new blkdev_{get,put}_no_open low-level interface is added
> to replace the previous get_gendisk use.
>
> Note that the change to look up block device directly instead of the two
> step lookup using struct gendisk causes a subtile change in behavior:
> accessing a non-existing partition on an existing block device can now
> cause a call to request_module. That call is harmless, and in practice
> no recent system will access these nodes as they aren't created by udev
> and static /dev/ setups are unusual.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> block/blk-cgroup.c | 42 ++++----
> block/blk-iocost.c | 36 +++----
> block/blk.h | 2 +-
> block/genhd.c | 210 +++++--------------------------------
> block/partitions/core.c | 29 ++---
> fs/block_dev.c | 177 +++++++++++++++++--------------
> include/linux/blk-cgroup.h | 4 +-
> include/linux/blkdev.h | 6 ++
> include/linux/genhd.h | 7 +-
> 9 files changed, 194 insertions(+), 319 deletions(-)
>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cheers,
Hannes
--
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next prev parent reply other threads:[~2020-11-30 7:36 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-28 16:14 [dm-devel] merge struct block_device and struct hd_struct v4 Christoph Hellwig
2020-11-28 16:14 ` [dm-devel] [PATCH 01/45] blk-cgroup: fix a hd_struct leak in blkcg_fill_root_iostats Christoph Hellwig
2020-11-28 16:14 ` [dm-devel] [PATCH 02/45] filemap: consistently use ->f_mapping over ->i_mapping Christoph Hellwig
2020-11-30 9:20 ` Johannes Thumshirn
2020-11-28 16:14 ` [dm-devel] [PATCH 03/45] fs: remove get_super_thawed and get_super_exclusive_thawed Christoph Hellwig
2020-11-28 16:14 ` [dm-devel] [PATCH 04/45] fs: simplify freeze_bdev/thaw_bdev Christoph Hellwig
2020-11-30 17:55 ` Darrick J. Wong
2020-11-28 16:14 ` [dm-devel] [PATCH 05/45] mtip32xx: remove the call to fsync_bdev on removal Christoph Hellwig
2020-11-30 7:07 ` Hannes Reinecke
2020-11-30 14:48 ` Johannes Thumshirn
2020-11-28 16:14 ` [dm-devel] [PATCH 06/45] zram: do not call set_blocksize Christoph Hellwig
2020-11-28 16:14 ` [dm-devel] [PATCH 07/45] loop: " Christoph Hellwig
2020-11-30 7:07 ` Hannes Reinecke
2020-11-30 11:26 ` Johannes Thumshirn
2020-11-28 16:14 ` [dm-devel] [PATCH 08/45] dm: simplify flush_bio initialization in __send_empty_flush Christoph Hellwig
2020-11-30 7:08 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 09/45] dm: remove the block_device reference in struct mapped_device Christoph Hellwig
2020-11-28 16:14 ` [dm-devel] [PATCH 10/45] block: remove a duplicate __disk_get_part prototype Christoph Hellwig
2020-11-28 16:14 ` [dm-devel] [PATCH 11/45] block: remove a superflous check in blkpg_do_ioctl Christoph Hellwig
2020-11-30 9:20 ` Johannes Thumshirn
2020-11-28 16:14 ` [dm-devel] [PATCH 12/45] block: add a bdev_kobj helper Christoph Hellwig
2020-11-28 16:14 ` [dm-devel] [PATCH 13/45] block: use disk_part_iter_exit in disk_part_iter_next Christoph Hellwig
2020-11-28 16:14 ` [dm-devel] [PATCH 14/45] block: use put_device in put_disk Christoph Hellwig
2020-11-30 7:09 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 15/45] block: change the hash used for looking up block devices Christoph Hellwig
2020-11-30 7:10 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 16/45] block: switch bdgrab to use igrab Christoph Hellwig
2020-11-30 7:14 ` Hannes Reinecke
2020-11-30 9:09 ` Jan Kara
2020-11-30 14:52 ` Johannes Thumshirn
2020-11-28 16:14 ` [dm-devel] [PATCH 17/45] init: refactor name_to_dev_t Christoph Hellwig
2020-11-30 7:15 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 18/45] init: refactor devt_from_partuuid Christoph Hellwig
2020-11-30 7:16 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 19/45] init: cleanup match_dev_by_uuid and match_dev_by_label Christoph Hellwig
2020-11-30 7:17 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 20/45] block: refactor __blkdev_put Christoph Hellwig
2020-11-30 7:17 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 21/45] block: refactor blkdev_get Christoph Hellwig
2020-11-30 7:28 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 22/45] block: move bdput() to the callers of __blkdev_get Christoph Hellwig
2020-11-30 7:29 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 23/45] block: opencode devcgroup_inode_permission Christoph Hellwig
2020-11-30 7:30 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 24/45] block: remove i_bdev Christoph Hellwig
2020-11-30 7:31 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 25/45] block: simplify bdev/disk lookup in blkdev_get Christoph Hellwig
2020-11-30 7:36 ` Hannes Reinecke [this message]
2020-11-30 9:24 ` Jan Kara
2020-12-02 21:52 ` Tejun Heo
2020-11-28 16:14 ` [dm-devel] [PATCH 26/45] block: remove ->bd_contains Christoph Hellwig
2020-11-30 7:37 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 27/45] block: simplify the block device claiming interface Christoph Hellwig
2020-11-30 7:37 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 28/45] block: simplify part_to_disk Christoph Hellwig
2020-11-30 7:38 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 29/45] block: initialize struct block_device in bdev_alloc Christoph Hellwig
2020-11-30 7:38 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 30/45] block: remove the nr_sects field in struct hd_struct Christoph Hellwig
2020-11-30 7:39 ` Hannes Reinecke
2020-11-30 9:44 ` Jan Kara
2020-11-30 14:51 ` Christoph Hellwig
2020-11-30 15:17 ` Jan Kara
2020-11-28 16:14 ` [dm-devel] [PATCH 31/45] block: move disk stat accounting to struct block_device Christoph Hellwig
2020-11-30 7:40 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 32/45] block: move the start_sect field " Christoph Hellwig
2020-11-30 7:41 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 33/45] block: move the partition_meta_info " Christoph Hellwig
2020-11-30 7:41 ` Hannes Reinecke
2020-11-28 16:14 ` [dm-devel] [PATCH 34/45] block: move holder_dir " Christoph Hellwig
2020-11-30 7:42 ` Hannes Reinecke
2020-11-28 16:15 ` [dm-devel] [PATCH 35/45] block: move make_it_fail " Christoph Hellwig
2020-11-30 7:43 ` Hannes Reinecke
2020-11-28 16:15 ` [dm-devel] [PATCH 36/45] block: move the policy field " Christoph Hellwig
2020-11-30 7:44 ` Hannes Reinecke
2020-11-28 16:15 ` [dm-devel] [PATCH 37/45] block: allocate struct hd_struct as part of struct bdev_inode Christoph Hellwig
2020-11-30 7:46 ` Hannes Reinecke
2020-11-30 9:53 ` Jan Kara
2020-11-28 16:15 ` [dm-devel] [PATCH 38/45] block: switch partition lookup to use struct block_device Christoph Hellwig
2020-11-30 7:47 ` Hannes Reinecke
2020-11-28 16:15 ` [dm-devel] [PATCH 39/45] block: remove the partno field from struct hd_struct Christoph Hellwig
2020-11-30 7:47 ` Hannes Reinecke
2020-11-28 16:15 ` [dm-devel] [PATCH 40/45] block: pass a block_device to blk_alloc_devt Christoph Hellwig
2020-11-30 7:48 ` Hannes Reinecke
2020-11-28 16:15 ` [dm-devel] [PATCH 41/45] block: pass a block_device to invalidate_partition Christoph Hellwig
2020-11-30 7:49 ` Hannes Reinecke
2020-11-28 16:15 ` [dm-devel] [PATCH 42/45] block: switch disk_part_iter_* to use a struct block_device Christoph Hellwig
2020-11-30 7:50 ` Hannes Reinecke
2020-11-30 10:20 ` Jan Kara
2020-11-28 16:15 ` [dm-devel] [PATCH 43/45] f2fs: remove a few bd_part checks Christoph Hellwig
2020-11-30 7:50 ` Hannes Reinecke
2020-11-28 16:15 ` [dm-devel] [PATCH 44/45] block: merge struct block_device and struct hd_struct Christoph Hellwig
2020-11-30 7:51 ` Hannes Reinecke
2020-11-30 10:29 ` Jan Kara
2020-11-28 16:15 ` [dm-devel] [PATCH 45/45] block: stop using bdget_disk for partition 0 Christoph Hellwig
2020-11-30 7:51 ` Hannes Reinecke
2020-11-30 17:19 ` [dm-devel] merge struct block_device and struct hd_struct v4 Christoph Hellwig
2020-11-30 17:51 ` Jens Axboe
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