WSL2-Linux-Kernel/sound/core
Christoph Hellwig 6b2f3d1f76 vfs: Implement proper O_SYNC semantics
While Linux provided an O_SYNC flag basically since day 1, it took until
Linux 2.4.0-test12pre2 to actually get it implemented for filesystems,
since that day we had generic_osync_around with only minor changes and the
great "For now, when the user asks for O_SYNC, we'll actually give
O_DSYNC" comment.  This patch intends to actually give us real O_SYNC
semantics in addition to the O_DSYNC semantics.  After Jan's O_SYNC
patches which are required before this patch it's actually surprisingly
simple, we just need to figure out when to set the datasync flag to
vfs_fsync_range and when not.

This patch renames the existing O_SYNC flag to O_DSYNC while keeping it's
numerical value to keep binary compatibility, and adds a new real O_SYNC
flag.  To guarantee backwards compatiblity it is defined as expanding to
both the O_DSYNC and the new additional binary flag (__O_SYNC) to make
sure we are backwards-compatible when compiled against the new headers.

This also means that all places that don't care about the differences can
just check O_DSYNC and get the right behaviour for O_SYNC, too - only
places that actuall care need to check __O_SYNC in addition.  Drivers and
network filesystems have been updated in a fail safe way to always do the
full sync magic if O_DSYNC is set.  The few places setting O_SYNC for
lower layers are kept that way for now to stay failsafe.

We enforce that O_DSYNC is set when __O_SYNC is set early in the open path
to make sure we always get these sane options.

Note that parisc really screwed up their headers as they already define a
O_DSYNC that has always been a no-op.  We try to repair it by using it for
the new O_DSYNC and redefinining O_SYNC to send both the traditional
O_SYNC numerical value _and_ the O_DSYNC one.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger@sun.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-12-10 15:02:50 +01:00
..
oss ALSA: rename "PC Speaker" controls to "Speaker" 2009-11-05 09:00:21 +01:00
seq Merge branch 'topic/midi' into for-linus 2009-09-10 15:32:56 +02:00
Kconfig ALSA: Fix SG-buffer DMA with non-coherent architectures 2009-07-08 14:20:20 +02:00
Makefile ALSA: Fix SG-buffer DMA with non-coherent architectures 2009-07-08 14:20:20 +02:00
control.c Merge branch 'topic/misc' into for-linus 2009-12-04 16:22:37 +01:00
control_compat.c ALSA: Kill snd_assert() in sound/core/* 2008-08-13 11:46:35 +02:00
device.c ALSA: Print function symbol in the error messages 2008-10-16 16:17:30 +02:00
hrtimer.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-12-30 16:16:21 -08:00
hwdep.c ALSA: hwdep - Make open callback optional 2009-02-05 09:10:20 +01:00
hwdep_compat.c [PATCH] hwdep_compat missed __user annotations 2006-10-10 15:37:21 -07:00
info.c Merge branch 'topic/dummy' into for-linus 2009-09-10 15:32:51 +02:00
info_oss.c ALSA: Kill snd_assert() in sound/core/* 2008-08-13 11:46:35 +02:00
init.c ALSA: Remove struct snd_monitor_file from public sound/core.h 2009-09-07 15:50:18 +02:00
isadma.c ALSA: snd_dma_pointer workaround for chipsets with buggy DMA 2009-10-11 18:03:13 +02:00
jack.c ALSA: use card device as parent for jack input-devices 2009-06-10 19:50:33 +02:00
memalloc.c ALSA: Fix SG-buffer DMA with non-coherent architectures 2009-07-08 14:20:20 +02:00
memory.c [ALSA] Remove sound/driver.h 2008-01-31 17:29:48 +01:00
misc.c ALSA: Add debug module option 2009-08-27 17:42:08 +02:00
pcm.c sound: pcm: record a substream's owner process 2009-11-10 16:32:20 +01:00
pcm_compat.c ALSA: sound/core: use memdup_user() 2009-04-14 12:39:12 +02:00
pcm_lib.c Merge branch 'topic/pcm-drain-nonblock' into for-linus 2009-09-10 15:33:00 +02:00
pcm_memory.c ALSA: Fix SG-buffer DMA with non-coherent architectures 2009-07-08 14:20:20 +02:00
pcm_misc.c sound: add missing pcm kernel-doc 2008-10-18 11:05:36 +02:00
pcm_native.c ALSA: pcm - fix page conversion on non-coherent PPC arch 2009-11-27 10:15:23 +01:00
pcm_timer.c ALSA: Remove unneeded snd_pcm_substream.timer_lock 2009-03-09 14:02:00 +01:00
rawmidi.c vfs: Implement proper O_SYNC semantics 2009-12-10 15:02:50 +01:00
rawmidi_compat.c [ALSA] Remove xxx_t typedefs: Raw MIDI 2006-01-03 12:17:35 +01:00
rtctimer.c ALSA: hda - Convert from takslet_hi_schedule() to tasklet_schedule() 2008-12-18 12:17:55 +01:00
sgbuf.c ALSA: Fix vunmap and free order in snd_free_sgbuf_pages() 2009-03-18 08:04:01 +01:00
sound.c Check fops_get() return value 2009-01-06 15:59:11 -08:00
sound_oss.c ALSA: Kill snd_assert() in sound/core/* 2008-08-13 11:46:35 +02:00
timer.c ALSA: sound/core: use memdup_user() 2009-04-14 12:39:12 +02:00
timer_compat.c ALSA: Kill snd_assert() in sound/core/* 2008-08-13 11:46:35 +02:00
vmaster.c ALSA: Add new TLV types for dBwith min/max 2009-06-17 10:56:53 +02:00