mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
6b2f3d1f76
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>
36 lines
930 B
C
36 lines
930 B
C
/*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
|
* option) any later version.
|
|
*/
|
|
#include <linux/fs.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/mm.h>
|
|
|
|
#include <asm/bootinfo.h>
|
|
|
|
#include <loongson.h>
|
|
#include <mem.h>
|
|
|
|
void __init prom_init_memory(void)
|
|
{
|
|
add_memory_region(0x0, (memsize << 20), BOOT_MEM_RAM);
|
|
#ifdef CONFIG_64BIT
|
|
if (highmemsize > 0)
|
|
add_memory_region(LOONGSON_HIGHMEM_START,
|
|
highmemsize << 20, BOOT_MEM_RAM);
|
|
#endif /* CONFIG_64BIT */
|
|
}
|
|
|
|
/* override of arch/mips/mm/cache.c: __uncached_access */
|
|
int __uncached_access(struct file *file, unsigned long addr)
|
|
{
|
|
if (file->f_flags & O_DSYNC)
|
|
return 1;
|
|
|
|
return addr >= __pa(high_memory) ||
|
|
((addr >= LOONGSON_MMIO_MEM_START) &&
|
|
(addr < LOONGSON_MMIO_MEM_END));
|
|
}
|