From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Denis Efremov <efremov@linux.com>,
"David S. Miller" <davem@davemloft.net>,
Song Liu <song@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>,
Finn Thain <fthain@telegraphics.com.au>,
Michael Schmitz <schmitzmic@gmail.com>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-ide@vger.kernel.org, linux-raid@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-m68k@lists.linux-m68k.org
Subject: simplify gendisk lookup and remove struct block_device aliases v4
Date: Thu, 29 Oct 2020 15:58:23 +0100 [thread overview]
Message-ID: <20201029145841.144173-1-hch@lst.de> (raw)
Hi all,
this series removes the annoying struct block_device aliases, which can
happen for a bunch of old floppy drivers (and z2ram). In that case
multiple struct block device instances for different dev_t's can point
to the same gendisk, without being partitions. The cause for that
is the probe/get callback registered through blk_register_regions.
This series removes blk_register_region entirely, splitting it it into
a simple xarray lookup of registered gendisks, and a probe callback
stored in the major_names array that can be used for modprobe overrides
or creating devices on demands when no gendisk is found. The old
remapping is gone entirely, and instead the 4 remaining drivers just
register a gendisk for each operating mode. In case of the two drivers
that have lots of aliases that is done on-demand using the new probe
callback, while for the other two I simply register all at probe time
to keep things simple.
Note that the m68k drivers are compile tested only.
Changes since v3:
- keep kobj_map for char dev lookup for now, as the testbot found
some very strange and unexplained regressions, so I'll get back to
this later separately
- fix a commit message typo
Changes since v2:
- fix a wrong variable passed to ERR_PTR in the floppy driver
- slightly adjust the del_gendisk cleanups to prepare for the next
series touching this area
Changes since v1:
- add back a missing kobject_put in the cdev code
- improve the xarray delete loops
next reply other threads:[~2020-10-29 15:11 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-29 14:58 Christoph Hellwig [this message]
2020-10-29 14:58 ` [PATCH 01/18] block: cleanup del_gendisk a bit Christoph Hellwig
2020-10-29 14:58 ` [PATCH 02/18] block: open code kobj_map into in block/genhd.c Christoph Hellwig
2020-10-29 19:22 ` Greg Kroah-Hartman
2020-10-29 19:32 ` Christoph Hellwig
2020-10-30 10:40 ` Greg Kroah-Hartman
2020-10-30 10:49 ` Geert Uytterhoeven
2020-10-30 11:06 ` Greg Kroah-Hartman
2020-10-31 8:53 ` Christoph Hellwig
2020-10-29 14:58 ` [PATCH 03/18] block: split block_class_lock Christoph Hellwig
2020-10-29 14:58 ` [PATCH 04/18] block: rework requesting modules for unclaimed devices Christoph Hellwig
2020-10-29 14:58 ` [PATCH 05/18] block: add an optional probe callback to major_names Christoph Hellwig
2020-10-29 14:58 ` [PATCH 06/18] ide: remove ide_{,un}register_region Christoph Hellwig
2020-10-29 14:58 ` [PATCH 07/18] swim: don't call blk_register_region Christoph Hellwig
2020-10-29 14:58 ` [PATCH 08/18] sd: use __register_blkdev to avoid a modprobe for an unregistered dev_t Christoph Hellwig
2020-10-30 2:13 ` Martin K. Petersen
2020-10-29 14:58 ` [PATCH 09/18] brd: use __register_blkdev to allocate devices on demand Christoph Hellwig
2020-10-29 14:58 ` [PATCH 10/18] loop: " Christoph Hellwig
2020-10-29 14:58 ` [PATCH 11/18] md: " Christoph Hellwig
2020-10-29 14:58 ` [PATCH 12/18] ide: switch to __register_blkdev for command set probing Christoph Hellwig
2020-10-29 14:58 ` [PATCH 13/18] floppy: use a separate gendisk for each media format Christoph Hellwig
2020-10-29 14:58 ` [PATCH 14/18] amiflop: use separate gendisks for Amiga vs MS-DOS mode Christoph Hellwig
2020-10-29 14:58 ` [PATCH 15/18] ataflop: use a separate gendisk for each media format Christoph Hellwig
2020-10-29 14:58 ` [PATCH 16/18] z2ram: reindent Christoph Hellwig
2020-10-29 14:58 ` [PATCH 17/18] z2ram: use separate gendisk for the different modes Christoph Hellwig
2020-10-30 0:11 ` [PATCH] z2ram: MODULE_LICENSE update and neatening Joe Perches
2020-10-30 1:01 ` James Bottomley
2020-10-30 1:23 ` Joe Perches
2020-10-29 14:58 ` [PATCH 18/18] block: switch gendisk lookup to a simple xarray Christoph Hellwig
2020-11-11 7:57 ` simplify gendisk lookup and remove struct block_device aliases v4 Christoph Hellwig
2020-11-11 16:17 ` Jens Axboe
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