linux_dsm_epyc7002/drivers/char
Tejun Heo e525fd89d3 block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.

* blkdev_get/put() are the primary open and close functions.

* bd_claim/release() deal with exclusive open.

* open/close_bdev_exclusive() are combination of open and claim and
  the other way around, respectively.

* bd_link/unlink_disk_holder() to create and remove holder/slave
  symlinks.

* open_by_devnum() wraps bdget() + blkdev_get().

The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access.  Reorganize the interface such that,

* blkdev_get() is extended to include exclusive access management.
  @holder argument is added and, if is @FMODE_EXCL specified, it will
  gain exclusive access atomically w.r.t. other exclusive accesses.

* blkdev_put() is similarly extended.  It now takes @mode argument and
  if @FMODE_EXCL is set, it releases an exclusive access.  Also, when
  the last exclusive claim is released, the holder/slave symlinks are
  removed automatically.

* bd_claim/release() and close_bdev_exclusive() are no longer
  necessary and either made static or removed.

* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
  is no longer necessary and removed.

* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
  and blkdev_get().  It also has an unexpected extra bdev_read_only()
  test which probably should be moved into blkdev_get().

* open_by_devnum() is modified to take @holder argument and pass it to
  blkdev_get().

Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should).  This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.

open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features.  Well, let's leave them for another day.

Most conversions are straight-forward.  drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
..
agp parisc-agp: fix missing slab.h include 2010-10-29 13:26:48 -04:00
hw_random llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
ip2 drivers/char/ip2/Makefile: replace the use of <module>-objs with <module>-y 2010-10-27 18:03:14 -07:00
ipmi drivers/char/ipmi/Makefile: replace the use of <module>-objs with <module>-y 2010-10-27 18:03:14 -07:00
mwave drivers/char/mwave/Makefile: clean up 2010-10-27 18:03:15 -07:00
pcmcia drivers/char/pcmcia/ipwireless/Makefile: Makefile: replace the use of <module>-objs with <module>-y 2010-10-27 18:03:15 -07:00
rio drivers/char/rio/Makefile: replace the use of <module>-objs with <module>-y 2010-10-27 18:03:15 -07:00
tpm Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
xilinx_hwicap Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
amiserial.c tty: icount changeover for other main devices 2010-10-22 10:20:05 -07:00
apm-emulation.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
applicom.c drivers/char/applicom.c: fix information leak to userland 2010-10-27 18:03:14 -07:00
applicom.h
bfin_jtag_comm.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
bfin-otp.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
briq_panel.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
bsr.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
cd1865.h
cs5535_gpio.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
cyclades.c tty: icount changeover for other main devices 2010-10-22 10:20:05 -07:00
digi1.h
digiFep1.h
digiPCI.h
ds1302.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
ds1620.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
dsp56k.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
dtlk.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
efirtc.c efirtc: explicitly set llseek to no_llseek 2009-12-16 07:19:59 -08:00
epca.c epca: Kill the big kernel lock 2010-08-10 13:47:40 -07:00
epca.h
epcaconfig.h
generic_nvram.c drivers: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:04 +02:00
generic_serial.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
genrtc.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
hangcheck-timer.c Input: sysrq - drop tty argument form handle_sysrq() 2010-08-21 00:34:45 -07:00
hpet.c drivers/char/hpet.c: fix information leak to userland 2010-10-26 16:52:11 -07:00
hvc_beat.c Merge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6 2010-02-25 15:38:37 -08:00
hvc_console.c drivers/char/hvc_console.c: remove unneeded __set_current_state(TASK_RUNNING) 2010-10-27 18:03:14 -07:00
hvc_console.h hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_irq.c
hvc_iseries.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
hvc_iucv.c [S390] hvc_iucv: do not call iucv_unregister if iucv_register failed 2010-10-25 16:10:17 +02:00
hvc_rtas.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_tile.c char: hvc: check for error case 2010-10-14 14:48:12 -04:00
hvc_udbg.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_vio.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_xen.c Merge branch 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen 2010-10-28 17:11:17 -07:00
hvcs.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hvsi.c Input: sysrq - drop tty argument form handle_sysrq() 2010-08-21 00:34:45 -07:00
i8k.c drivers: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:04 +02:00
isicom.c isicom: kill off the BKL 2010-08-10 13:47:40 -07:00
istallion.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
Kconfig add ttyprintk driver 2010-10-22 10:20:02 -07:00
lp.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
Makefile TTY: create drivers/tty/vt and move the vt code there 2010-11-05 08:16:52 -07:00
mbcs.c drivers: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:04 +02:00
mbcs.h
mem.c vfs: introduce FMODE_UNSIGNED_OFFSET for allowing negative f_pos 2010-10-25 21:18:21 -04:00
misc.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
mmtimer.c SGI Altix IA64 mmtimer: eliminate long interval timer holdoffs 2010-10-27 18:03:14 -07:00
moxa.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
moxa.h
mspec.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
mxser.c drivers/char/mxser.c: fix compilation warning in mxser.c 2010-10-27 18:03:15 -07:00
mxser.h
nozomi.c tty: icount changeover for other main devices 2010-10-22 10:20:05 -07:00
nsc_gpio.c
nvram.c drivers: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:04 +02:00
nwbutton.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
nwbutton.h
nwflash.c drivers: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:04 +02:00
pc8736x_gpio.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
ppdev.c drivers/char/ppdev.c: fix information leak to userland 2010-10-27 18:03:14 -07:00
ps3flash.c drop unused dentry argument to ->fsync 2010-05-27 22:05:02 -04:00
ramoops.c ramoops: use the platform data structure instead of module params 2010-10-27 18:03:18 -07:00
random.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
raw.c block: make blkdev_get/put() handle exclusive access 2010-11-13 11:55:17 +01:00
riscom8_reg.h
riscom8.c riscom8: kill use of lock_kernel 2010-08-10 13:47:40 -07:00
riscom8.h
rocket_int.h
rocket.c drivers/char/rocket.c: release_region or error path 2010-10-27 18:03:14 -07:00
rocket.h
rtc.c of/device: Replace struct of_device with struct platform_device 2010-08-06 09:25:50 -06:00
scc.h
scx200_gpio.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
ser_a2232.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
ser_a2232.h
ser_a2232fw.ax
ser_a2232fw.h
serial167.c tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
snsc_event.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
snsc.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
snsc.h
sonypi.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
specialix_io8.h
specialix.c tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
stallion.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
sx.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
sx.h
sxboards.h
sxwindow.h
synclink_gt.c drivers/char/synclink_gt.c: add extended sync feature 2010-10-27 18:03:14 -07:00
synclink.c tty: icount changeover for other main devices 2010-10-22 10:20:05 -07:00
synclinkmp.c tty: icount changeover for other main devices 2010-10-22 10:20:05 -07:00
tb0219.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
tlclk.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
toshiba.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
ttyprintk.c add ttyprintk driver 2010-10-22 10:20:02 -07:00
uv_mmtimer.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
viotape.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
virtio_console.c virtio: console: Disable lseek(2) for port file operations 2010-10-21 17:44:04 +10:30
vme_scc.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00