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https://github.com/adulau/aha.git
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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>
184 lines
4.2 KiB
C
184 lines
4.2 KiB
C
#ifndef _ASM_GENERIC_FCNTL_H
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#define _ASM_GENERIC_FCNTL_H
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#include <linux/types.h>
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#define O_ACCMODE 00000003
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#define O_RDONLY 00000000
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#define O_WRONLY 00000001
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#define O_RDWR 00000002
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#ifndef O_CREAT
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#define O_CREAT 00000100 /* not fcntl */
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#endif
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#ifndef O_EXCL
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#define O_EXCL 00000200 /* not fcntl */
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#endif
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#ifndef O_NOCTTY
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#define O_NOCTTY 00000400 /* not fcntl */
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#endif
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#ifndef O_TRUNC
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#define O_TRUNC 00001000 /* not fcntl */
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#endif
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#ifndef O_APPEND
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#define O_APPEND 00002000
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#endif
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#ifndef O_NONBLOCK
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#define O_NONBLOCK 00004000
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#endif
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#ifndef O_DSYNC
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#define O_DSYNC 00010000 /* used to be O_SYNC, see below */
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#endif
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#ifndef FASYNC
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#define FASYNC 00020000 /* fcntl, for BSD compatibility */
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#endif
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#ifndef O_DIRECT
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#define O_DIRECT 00040000 /* direct disk access hint */
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#endif
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#ifndef O_LARGEFILE
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#define O_LARGEFILE 00100000
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#endif
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#ifndef O_DIRECTORY
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#define O_DIRECTORY 00200000 /* must be a directory */
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#endif
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#ifndef O_NOFOLLOW
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#define O_NOFOLLOW 00400000 /* don't follow links */
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#endif
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#ifndef O_NOATIME
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#define O_NOATIME 01000000
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#endif
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#ifndef O_CLOEXEC
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#define O_CLOEXEC 02000000 /* set close_on_exec */
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#endif
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/*
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* Before Linux 2.6.32 only O_DSYNC semantics were implemented, but using
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* the O_SYNC flag. We continue to use the existing numerical value
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* for O_DSYNC semantics now, but using the correct symbolic name for it.
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* This new value is used to request true Posix O_SYNC semantics. It is
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* defined in this strange way to make sure applications compiled against
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* new headers get at least O_DSYNC semantics on older kernels.
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*
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* This has the nice side-effect that we can simply test for O_DSYNC
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* wherever we do not care if O_DSYNC or O_SYNC is used.
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*
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* Note: __O_SYNC must never be used directly.
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*/
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#ifndef O_SYNC
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#define __O_SYNC 04000000
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#define O_SYNC (__O_SYNC|O_DSYNC)
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#endif
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#ifndef O_NDELAY
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#define O_NDELAY O_NONBLOCK
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#endif
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#define F_DUPFD 0 /* dup */
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#define F_GETFD 1 /* get close_on_exec */
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#define F_SETFD 2 /* set/clear close_on_exec */
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#define F_GETFL 3 /* get file->f_flags */
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#define F_SETFL 4 /* set file->f_flags */
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#ifndef F_GETLK
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#define F_GETLK 5
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#define F_SETLK 6
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#define F_SETLKW 7
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#endif
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#ifndef F_SETOWN
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#define F_SETOWN 8 /* for sockets. */
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#define F_GETOWN 9 /* for sockets. */
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#endif
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#ifndef F_SETSIG
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#define F_SETSIG 10 /* for sockets. */
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#define F_GETSIG 11 /* for sockets. */
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#endif
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#ifndef CONFIG_64BIT
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#ifndef F_GETLK64
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#define F_GETLK64 12 /* using 'struct flock64' */
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#define F_SETLK64 13
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#define F_SETLKW64 14
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#endif
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#endif
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#ifndef F_SETOWN_EX
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#define F_SETOWN_EX 15
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#define F_GETOWN_EX 16
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#endif
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#define F_OWNER_TID 0
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#define F_OWNER_PID 1
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#define F_OWNER_PGRP 2
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struct f_owner_ex {
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int type;
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pid_t pid;
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};
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/* for F_[GET|SET]FL */
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#define FD_CLOEXEC 1 /* actually anything with low bit set goes */
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/* for posix fcntl() and lockf() */
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#ifndef F_RDLCK
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#define F_RDLCK 0
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#define F_WRLCK 1
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#define F_UNLCK 2
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#endif
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/* for old implementation of bsd flock () */
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#ifndef F_EXLCK
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#define F_EXLCK 4 /* or 3 */
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#define F_SHLCK 8 /* or 4 */
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#endif
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/* for leases */
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#ifndef F_INPROGRESS
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#define F_INPROGRESS 16
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#endif
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/* operations for bsd flock(), also used by the kernel implementation */
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#define LOCK_SH 1 /* shared lock */
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#define LOCK_EX 2 /* exclusive lock */
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#define LOCK_NB 4 /* or'd with one of the above to prevent
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blocking */
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#define LOCK_UN 8 /* remove lock */
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#define LOCK_MAND 32 /* This is a mandatory flock ... */
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#define LOCK_READ 64 /* which allows concurrent read operations */
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#define LOCK_WRITE 128 /* which allows concurrent write operations */
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#define LOCK_RW 192 /* which allows concurrent read & write ops */
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#define F_LINUX_SPECIFIC_BASE 1024
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#ifndef HAVE_ARCH_STRUCT_FLOCK
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#ifndef __ARCH_FLOCK_PAD
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#define __ARCH_FLOCK_PAD
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#endif
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struct flock {
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short l_type;
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short l_whence;
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__kernel_off_t l_start;
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__kernel_off_t l_len;
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__kernel_pid_t l_pid;
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__ARCH_FLOCK_PAD
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};
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#endif
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#ifndef CONFIG_64BIT
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#ifndef HAVE_ARCH_STRUCT_FLOCK64
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#ifndef __ARCH_FLOCK64_PAD
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#define __ARCH_FLOCK64_PAD
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#endif
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struct flock64 {
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short l_type;
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short l_whence;
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__kernel_loff_t l_start;
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__kernel_loff_t l_len;
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__kernel_pid_t l_pid;
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__ARCH_FLOCK64_PAD
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};
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#endif
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#endif /* !CONFIG_64BIT */
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#endif /* _ASM_GENERIC_FCNTL_H */
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