kernel_optimize_test/include/asm-generic
Sage Weil b7ed78f565 introduce sys_syncfs to sync a single file system
It is frequently useful to sync a single file system, instead of all
mounted file systems via sync(2):

 - On machines with many mounts, it is not at all uncommon for some of
   them to hang (e.g. unresponsive NFS server).  sync(2) will get stuck on
   those and may never get to the one you do care about (e.g., /).
 - Some applications write lots of data to the file system and then
   want to make sure it is flushed to disk.  Calling fsync(2) on each
   file introduces unnecessary ordering constraints that result in a large
   amount of sub-optimal writeback/flush/commit behavior by the file
   system.

There are currently two ways (that I know of) to sync a single super_block:

 - BLKFLSBUF ioctl on the block device: That also invalidates the bdev
   mapping, which isn't usually desirable, and doesn't work for non-block
   file systems.
 - 'mount -o remount,rw' will call sync_filesystem as an artifact of the
   current implemention.  Relying on this little-known side effect for
   something like data safety sounds foolish.

Both of these approaches require root privileges, which some applications
do not have (nor should they need?) given that sync(2) is an unprivileged
operation.

This patch introduces a new system call syncfs(2) that takes an fd and
syncs only the file system it references.  Maybe someday we can

 $ sync /some/path

and not get

 sync: ignoring all arguments

The syscall is motivated by comments by Al and Christoph at the last LSF.
syncfs(2) seems like an appropriate name given statfs(2).

A similar ioctl was also proposed a while back, see
	http://marc.info/?l=linux-fsdevel&m=127970513829285&w=2

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-21 00:40:29 -04:00
..
bitops bitops: remove duplicated extern declarations 2010-10-09 21:51:45 +02:00
4level-fixup.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
atomic64.h lib: Provide generic atomic64_t implementation 2009-06-15 13:27:38 +10:00
atomic-long.h asm-generic: merge branch 'master' of torvalds/linux-2.6 2009-06-12 11:32:58 +02:00
atomic.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic 2010-10-22 11:17:06 -07:00
audit_change_attr.h audit: make link()/linkat() match "attribute change" predicate 2010-10-30 08:45:43 -04:00
audit_dir_write.h
audit_read.h
audit_signal.h
audit_write.h [PATCH] asm/generic: fix bug - kernel fails to build when enable some common audit code on Blackfin 2008-12-09 02:27:39 -05:00
auxvec.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
bitops.h asm-generic: make bitops.h usable 2009-06-11 21:02:31 +02:00
bitsperlong.h asm-generic: introduce asm/bitsperlong.h 2009-06-11 21:02:14 +02:00
bug.h panic: Allow warnings to set different taint flags 2010-05-19 08:36:48 +01:00
bugs.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
cache.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
cacheflush.h block: add helpers to run flush_dcache_page() against a bio and a request's pages 2009-11-26 09:16:19 +01:00
checksum.h add generic lib/checksum.c 2009-06-11 21:02:51 +02:00
cmpxchg-local.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
cmpxchg.h
cputime.h time: Add nsecs_to_cputime64 interface for asm-generic 2011-01-26 12:33:20 +01:00
current.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
delay.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
device.h Driver Core: Add platform device arch data V3 2009-07-22 00:28:38 +02:00
div64.h
dma-coherent.h
dma-mapping-broken.h dma-mapping: remove dma_is_consistent API 2010-08-11 08:59:21 -07:00
dma-mapping-common.h dma-mapping: remove unnecessary sync_single_range_* in dma_map_ops 2010-05-27 09:12:52 -07:00
dma.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
emergency-restart.h
errno-base.h
errno.h mm: make __get_user_pages return -EHWPOISON for HWPOISON page optionally 2011-03-17 13:08:27 -03:00
fb.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
fcntl.h New kind of open files - "location only". 2011-03-15 02:21:45 -04:00
ftrace.h asm-generic headers: add ftrace.h 2011-03-17 09:19:04 +08:00
futex.h futex: Sanitize futex ops argument types 2011-03-11 12:23:31 +01:00
getorder.h asm-generic: rename page.h and uaccess.h 2009-06-11 21:02:17 +02:00
gpio.h Revert "gpiolib: annotate gpio-intialization with __must_check" 2011-01-13 17:26:46 -08:00
hardirq.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
hw_irq.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
ide_iops.h
int-l64.h asm-generic: introduce asm/bitsperlong.h 2009-06-11 21:02:14 +02:00
int-ll64.h asm-generic: introduce asm/bitsperlong.h 2009-06-11 21:02:14 +02:00
io.h asm-generic: fix inX/outX functions for architectures that have PCI 2011-03-17 09:19:03 +08:00
ioctl.h Make ioctl.h compatible with userland 2008-08-12 16:07:31 -07:00
ioctls.h tty: add TIOCVHANGUP to allow clean tty shutdown of all ttys 2011-02-17 14:16:30 -08:00
iomap.h
ipcbuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
irq_regs.h core: Replace __get_cpu_var with __this_cpu_read if not used for an address. 2010-12-17 15:07:19 +01:00
irq.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
irqflags.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
Kbuild include: replace unifdef-y with header-y 2010-08-14 22:26:51 +02:00
Kbuild.asm include: replace unifdef-y with header-y 2010-08-14 22:26:51 +02:00
kdebug.h asm-generic: kdebug.h: Checkpatch cleanup 2010-10-09 21:51:44 +02:00
kmap_types.h include/asm-generic/kmap_types.h: add helpful reminder 2010-05-25 08:07:03 -07:00
libata-portmap.h
linkage.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
local64.h arch: Implement local64_t 2010-06-09 11:12:36 +02:00
local.h local_t: Remove cpu_local_xx macros 2010-01-05 15:34:49 +09:00
memory_model.h tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
mm_hooks.h
mman-common.h thp: mm: define MADV_NOHUGEPAGE 2011-01-13 17:32:47 -08:00
mman.h mm: add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions 2009-09-22 07:17:41 -07:00
mmu_context.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
mmu.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
module.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
msgbuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
mutex-dec.h mutex: speed up generic mutex implementations 2008-10-23 09:18:20 -07:00
mutex-null.h
mutex-xchg.h mutex: speed up generic mutex implementations 2008-10-23 09:18:20 -07:00
mutex.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
page.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
param.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
parport.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
pci-dma-compat.h dma-mapping: pci: move pci_set_dma_mask and pci_set_consistent_dma_mask to pci-dma-compat.h 2010-03-12 15:52:42 -08:00
pci.h PCI: remove pcibios_scan_all_fns() 2009-09-09 13:29:18 -07:00
percpu.h percpu: Optimize __get_cpu_var() 2010-09-10 10:56:51 +02:00
pgalloc.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
pgtable-nopmd.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
pgtable-nopud.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
pgtable.h mm: <asm-generic/pgtable.h> must include <linux/mm_types.h> 2011-02-28 17:46:49 -08:00
poll.h
posix_types.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
resource.h
rtc.h asm-generic: make get_rtc_time overridable 2009-06-11 21:02:18 +02:00
scatterlist.h asm-generic: remove ARCH_HAS_SG_CHAIN in scatterlist.h 2010-05-27 09:12:54 -07:00
sections.h x86: Separate out entry text section 2011-03-08 17:22:11 +01:00
segment.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
sembuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
serial.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
setup.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
shmbuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
shmparam.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
siginfo.h HWPOISON: Add new SIGBUS error codes for hardware poison signals 2009-09-16 11:50:06 +02:00
signal-defs.h asm-generic: rename termios.h, signal.h and mman.h 2009-06-11 21:01:52 +02:00
signal.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
sizes.h asm-generic headers: add sizes.h 2011-03-17 09:19:04 +08:00
socket.h net: Generalize socket rx gap / receive queue overflow cmsg 2009-10-12 13:26:31 -07:00
sockios.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
spinlock.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
stat.h asm-generic/stat.h: support 64-bit file time_t for stat() 2010-11-01 15:31:29 -04:00
statfs.h add f_flags to struct statfs(64) 2010-08-09 16:48:44 -04:00
string.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
swab.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
syscall.h asm-generic: syscall_get_nr returns int 2009-09-22 19:56:50 -07:00
syscalls.h Fix the declaration of sys_execve() in asm-generic/syscalls.h 2010-08-18 12:12:38 -07:00
system.h asm-generic: cmpxchg does not handle non-long arguments 2010-10-09 21:51:27 +02:00
termbits.h tty: Add EXTPROC support for LINEMODE 2010-08-10 13:47:39 -07:00
termios-base.h asm-generic: rename termios.h, signal.h and mman.h 2009-06-11 21:01:52 +02:00
termios.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
timex.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
tlb.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
tlbflush.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
topology.h topology: alternate fix for ia64 tiger_defconfig build breakage 2010-08-09 20:44:57 -07:00
types.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
uaccess-unaligned.h asm-generic: rename page.h and uaccess.h 2009-06-11 21:02:17 +02:00
uaccess.h asm-generic headers: add arch-specific __strnlen_user calling in uaccess.h 2011-03-17 09:19:05 +08:00
ucontext.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
unaligned.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
unistd.h introduce sys_syncfs to sync a single file system 2011-03-21 00:40:29 -04:00
user.h asm-generic/user.h: Fix spelling in comment 2011-03-01 15:49:39 +01:00
vga.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
vmlinux.lds.h Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-03-16 08:22:41 -07:00
xor.h