Instead of always creating a huge (268K) deflate_workspace with the
maximum compression parameters (windowBits=15, memLevel=8), allow the
caller to obtain a smaller workspace by specifying smaller parameter
values.
For example, when capturing oops and panic reports to a medium with
limited capacity, such as NVRAM, compression may be the only way to
capture the whole report. In this case, a small workspace (24K works
fine) is a win, whether you allocate the workspace when you need it (i.e.,
during an oops or panic) or at boot time.
I've verified that this patch works with all accepted values of windowBits
(positive and negative), memLevel, and compression level.
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
d_alloc_name return NULL in case error, but we expect errno in
devpts_pty_new.
Addresses http://bugzilla.openvz.org/show_bug.cgi?id=1758
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The test program below will hang because io_getevents() uses
add_wait_queue_exclusive(), which means the wake_up() in io_destroy() only
wakes up one of the threads. Fix this by using wake_up_all() in the aio
code paths where we want to make sure no one gets stuck.
// t.c -- compile with gcc -lpthread -laio t.c
#include <libaio.h>
#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
static const int nthr = 2;
void *getev(void *ctx)
{
struct io_event ev;
io_getevents(ctx, 1, 1, &ev, NULL);
printf("io_getevents returned\n");
return NULL;
}
int main(int argc, char *argv[])
{
io_context_t ctx = 0;
pthread_t thread[nthr];
int i;
io_setup(1024, &ctx);
for (i = 0; i < nthr; ++i)
pthread_create(&thread[i], NULL, getev, ctx);
sleep(1);
io_destroy(ctx);
for (i = 0; i < nthr; ++i)
pthread_join(thread[i], NULL);
return 0;
}
Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ADFS (FileCore) storage complies with the RISC OS filetype specification
(12 bits of file type information is stored in the file load address,
rather than using a file extension). The existing driver largely ignores
this information and does not present it to the end user.
It is desirable that stored filetypes be made visible to the end user to
facilitate a precise copy of data and metadata from a hard disc (or image
thereof) into a RISC OS emulator (such as RPCEmu) or to a network share
which can be accessed by real Acorn systems.
This patch implements a per-mount filetype suffix option (use -o
ftsuffix=1) to present any filetype as a ,xyz hexadecimal suffix on each
file. This type suffix is compatible with that used by RISC OS systems
that access network servers using NFS client software and by RPCemu's host
filing system.
Signed-off-by: Stuart Swales <stuart.swales.croftnuisk@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ADFS (FileCore) storage complies with the RISC OS timestamp specification
(40-bit centiseconds since 01 Jan 1900 00:00:00). It is desirable that
stored timestamp precision be maintained to facilitate a precise copy of
data and metadata from a hard disc (or image thereof) into a RISC OS
emulator (such as RPCEmu).
This patch implements a full-precision conversion from ADFS to Unix
timestamp as the existing driver, for ease of calculation with old 32-bit
compilers, uses the common trick of shifting the 40-bits representing
centiseconds around into 32-bits representing seconds thereby losing
precision.
Signed-off-by: Stuart Swales<stuart.swales.croftnuisk@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kernel crashes in fs/adfs module when accessing directories with a large
number of objects on mounted Acorn ADFS E+/F+ format discs (or images) as
the existing code writes off the end of the fixed array of struct
buffer_head pointers.
Additionally, each directory access that didn't crash would leak a buffer
as nr_buffers was not adjusted correctly for E+/F+ discs (was always left
as one less than required).
The patch fixes this by allocating a dynamically-sized set of struct
buffer_head pointers if necessary for the E+/F+ case (many directories
still do in fact fit in 2048 bytes) and sets the correct nr_buffers so
that all buffers are released.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=26072
Tested by tar'ing the contents of my RISC PC's E+ format 20Gb HDD which
contains a number of large directories that previously crashed the kernel.
Signed-off-by: Stuart Swales <stuart.swales.croftnuisk@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When CONFIG_SYSCTL=n, we get the following warning:
fs/coda/sysctl.c:18: warning: `coda_tabl' defined but not used
Fix the warning by making sure coda_table and it's callee function are in
the same context. Also clean up the code by removing extra #ifdef.
[akpm@linux-foundation.org: remove unneeded stub macros]
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With GCC-4.6 we get warnings about things being 'set but not used'.
In load_elf_binary() this can happen with reloc_func_desc if ELF_PLAT_INIT
is defined, but doesn't use the reloc_func_desc argument.
Quiet the warning/error by marking reloc_func_desc as __maybe_unused.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a comment to ep_poll(), rename labels a bit clearly, fix a warning of
unused variable from gcc and optimize the non-blocking path a little.
Hinted-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
hannes@cmpxchg.org:
: The non-blocking ep_poll path optimization introduced skipping over the
: return value setup.
:
: Initialize it properly, my userspace gets upset by epoll_wait() returning
: random things.
:
: In addition, remove the reinitialization at the fetch_events label, the
: return value is garuanteed to be zero when execution reaches there.
[hannes@cmpxchg.org: fix initialization]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shawn Bohrer <shawn.bohrer@gmail.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the event readiness check into a proper inline, and use it uniformly
inside ep_poll() code. Events in the ->ovflist are no less ready than the
ones in ->rdllist.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Shawn Bohrer <shawn.bohrer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
printk()s without a priority level default to KERN_WARNING. To reduce
noise at KERN_WARNING, this patch set the priority level appriopriately
for unleveled printks()s. This should be useful to folks that look at
dmesg warnings closely.
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that the mere act of _looking_ at /proc/$pid/smaps will not destroy
transparent huge pages, tell how much of the VMA is actually mapped with
them.
This way, we can make sure that we're getting THPs where we
expect to see them.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Eric B Munson <emunson@mgebm.net>
Tested-by: Eric B Munson <emunson@mgebm.net>
Cc: Michael J Wolf <mjwolf@us.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds code to explicitly detect and handle pmd_trans_huge() pmds. It
then passes HPAGE_SIZE units in to the smap_pte_entry() function instead
of PAGE_SIZE.
This means that using /proc/$pid/smaps now will no longer cause THPs to be
broken down in to small pages.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: Eric B Munson <emunson@mgebm.net>
Tested-by: Eric B Munson <emunson@mgebm.net>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michael J Wolf <mjwolf@us.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add an argument to the new smaps_pte_entry() function to let it account in
things other than PAGE_SIZE units. I changed all of the PAGE_SIZE sites,
even though not all of them can be reached for transparent huge pages,
just so this will continue to work without changes as THPs are improved.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Eric B Munson <emunson@mgebm.net>
Tested-by: Eric B Munson <emunson@mgebm.net>
Cc: Michael J Wolf <mjwolf@us.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We will use smaps_pte_entry() in a moment to handle both small and
transparent large pages. But, we must break it out of smaps_pte_range()
first.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Eric B Munson <emunson@mgebm.net>
Tested-by: Eric B Munson <emunson@mgebm.net>
Cc: Michael J Wolf <mjwolf@us.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now, if a mm_walk has either ->pte_entry or ->pmd_entry set, it will
unconditionally split any transparent huge pages it runs in to. In
practice, that means that anyone doing a
cat /proc/$pid/smaps
will unconditionally break down every huge page in the process and depend
on khugepaged to re-collapse it later. This is fairly suboptimal.
This patch changes that behavior. It teaches each ->pmd_entry handler
(there are five) that they must break down the THPs themselves. Also, the
_generic_ code will never break down a THP unless a ->pte_entry handler is
actually set.
This means that the ->pmd_entry handlers can now choose to deal with THPs
without breaking them down.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Eric B Munson <emunson@mgebm.net>
Tested-by: Eric B Munson <emunson@mgebm.net>
Cc: Michael J Wolf <mjwolf@us.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch series changes remove_from_page_cache()'s page ref counting
rule. Page cache ref count is decreased in delete_from_page_cache(). So
we don't need to decrease the page reference in callers.
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: William Irwin <wli@holomorphy.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function basically does:
remove_from_page_cache(old);
page_cache_release(old);
add_to_page_cache_locked(new);
Except it does this atomically, so there's no possibility for the "add" to
fail because of a race.
If memory cgroups are enabled, then the memory cgroup charge is also moved
from the old page to the new.
This function is currently used by fuse to move pages into the page cache
on read, instead of copying the page contents.
[minchan.kim@gmail.com: add freepage() hook to replace_page_cache_page()]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
[net/9p]: Introduce basic flow-control for VirtIO transport.
9p: use the updated offset given by generic_write_checks
[net/9p] Don't re-pin pages on retrying virtqueue_add_buf().
[net/9p] Set the condition just before waking up.
[net/9p] unconditional wake_up to proc waiting for space on VirtIO ring
fs/9p: Add v9fs_dentry2v9ses
fs/9p: Attach writeback_fid on first open with WR flag
fs/9p: Open writeback fid in O_SYNC mode
fs/9p: Use truncate_setsize instead of vmtruncate
net/9p: Fix compile warning
net/9p: Convert the in the 9p rpc call path to GFP_NOFS
fs/9p: Fix race in initializing writeback fid
* git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
rbd: use watch/notify for changes in rbd header
libceph: add lingering request and watch/notify event framework
rbd: update email address in Documentation
ceph: rename dentry_release -> d_release, fix comment
ceph: add request to the tail of unsafe write list
ceph: remove request from unsafe list if it is canceled/timed out
ceph: move readahead default to fs/ceph from libceph
ceph: add ino32 mount option
ceph: update common header files
ceph: remove debugfs debug cruft
libceph: fix osd request queuing on osdmap updates
ceph: preserve I_COMPLETE across rename
libceph: Fix base64-decoding when input ends in newline.
Without this fix, even if a file is opened in O_APPEND mode, data will be
written at current file position instead of end of file.
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Add the new static inline and use the same
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We don't need writeback fid if we are only doing O_RDONLY open
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Older version of protocol don't support tsyncfs operation.
So for them force a O_SYNC flag on the server
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
convert vmtruncate usage to truncate_setsize. We also writeback
all dirty pages before doing 9p operations and on success call truncate_setsize.
This ensure that we continue sanely on failed truncate on the server. The
disadvantage is that we are now going to write back the content that get
thrown away later as a part of truncate.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
When two process open the same file we can end up with both of them
allocating the writeback_fid. Add a new mutex which can be used
for synchronizing v9fs_inode member values.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (23 commits)
xfs: don't name variables "panic"
xfs: factor agf counter updates into a helper
xfs: clean up the xfs_alloc_compute_aligned calling convention
xfs: kill support/debug.[ch]
xfs: Convert remaining cmn_err() callers to new API
xfs: convert the quota debug prints to new API
xfs: rename xfs_cmn_err_fsblock_zero()
xfs: convert xfs_fs_cmn_err to new error logging API
xfs: kill xfs_fs_mount_cmn_err() macro
xfs: kill xfs_fs_repair_cmn_err() macro
xfs: convert xfs_cmn_err to xfs_alert_tag
xfs: Convert xlog_warn to new logging interface
xfs: Convert linux-2.6/ files to new logging interface
xfs: introduce new logging API.
xfs: zero proper structure size for geometry calls
xfs: enable delaylog by default
xfs: more sensible inode refcounting for ialloc
xfs: stop using xfs_trans_iget in the RT allocator
xfs: check if device support discard in xfs_ioc_trim()
xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1
...
/sys/fs is a somewhat strange way to tweak what could more
obviously be tuned with a mount option.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In sync_write_wait(), we assume that the newest request is at the
tail of unsafe write list. We should maintain the semantics here.
Signed-off-by: Henry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The ino32 mount option forces the ceph fs to report 32 bit
ino values. This is useful for 64 bit kernels with 32 bit userspace.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
lookup_mnt() is only used in the core fs routines now, so it doesn't need to
be globally declared anymore. It isn't exported to modules at the moment, so
nothing that can be modularised seems to be using it.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Only bail out of fuse_dentry_revalidate() on LOOKUP_RCU when blocking
is actually necessary.
CC: Nick Piggin <npiggin@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Only bail out of fuse_permission() on IPERM_FLAG_RCU when blocking is
actually necessary.
CC: Nick Piggin <npiggin@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
If a fuse dev connection is broken, wake up any
processes that are blocking, in a poll system call,
on one of the files in the now defunct filesystem.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reduce the size of struct fuse_request by removing cuse_init_out from
the request structure and allocating it dinamically instead.
CC: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
The usage of find_first_zero_bit() in bfs_create() is wrong for two
reasons.
The bitmap size argument to find_first_zero_bit() is info->si_lasti but
the correct bitmap size is info->si_lasti + 1 as info->si_lasti is the
last valid index in info->si_imap bitmap.
Another problem is that it is impossible to detect that info->si_imap
bitmap is full because there is an off-by-one bug in the return value
check for find_first_zero_bit(). If no zero bits exist in info->si_imap,
find_first_zero_bit() returns info->si_lasti. But the check can't catch
it due to the off-by-one.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: "Tigran A. Aivazian" <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In this case nobody can open a slave point, so will be better return
from devpts_pty_new()
Now we should not check error code from d_find_alias() in
devpts_pty_kill(), because the dentry exists all times.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
These should be spin_unlock() instead of spin_lock(). It's a typo.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Move kfree() of i_private out of ->unlink() and into ->evict_inode()
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
Hi,
I was backporting the coredump over pipe feature and noticed this small typo,
I wish I would have something bigger to contribute...
>From 15d6080e0ed4267da103c706917a33b1015e8804 Mon Sep 17 00:00:00 2001
From: Holger Hans Peter Freyther <holger@moiji-mobile.com>
Date: Thu, 24 Feb 2011 17:42:50 +0100
Subject: [PATCH] fs: Fix a small typo in the comment
The function is called umh_pipe_setup not uhm_pipe_setup.
Signed-off-by: Holger Hans Peter Freyther <holger@moiji-mobile.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Remove the leftover from the commit 8ff3e8e85f ("select:
switch select() and poll() over to hrtimers").
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
