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
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
atomic64.h
lib: Provide generic atomic64_t implementation
2009-06-15 13:27:38 +10:00
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
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
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.h
asm-generic: add generic versions of common headers
2009-06-11 21:02:37 +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
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
local.h
local_t: Remove cpu_local_xx macros
2010-01-05 15:34:49 +09:00
local64.h
arch: Implement local64_t
2010-06-09 11:12:36 +02:00
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.h
asm-generic: add generic NOMMU versions of some headers
2009-06-11 21:02:50 +02:00
mmu_context.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-null.h
mutex-xchg.h
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