This patch fixes bz 450641.
This patch changes the computation for zero_metapath_length(), which it
renames to metapath_branch_start(). When you are extending the metadata
tree, The indirect blocks that point to the new data block must either
diverge from the existing tree either at the inode, or at the first
indirect block. They can diverge at the first indirect block because the
inode has room for 483 pointers while the indirect blocks have room for
509 pointers, so when the tree is grown, there is some free space in the
first indirect block. What metapath_branch_start() now computes is the
height where the first indirect block for the new data block is located.
It can either be 1 (if the indirect block diverges from the inode) or 2
(if it diverges from the first indirect block).
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch fixes bugzilla bug bz448866: gfs2: BUG: unable to
handle kernel paging request at ffff81002690e000.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Fix a sign issue in xdr_decode_fhstatus3()
Fix incorrect comparison in nfs_validate_mount_data()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Christian Borntraeger reported that reinstating cond_resched() with
CONFIG_PREEMPT caused a performance regression on lmbench:
For example select file 500:
23 microseconds
32 microseconds
and that's really because we totally unnecessarily do the cond_resched()
in the innermost loop of select(), which is just silly.
This moves it out from the innermost loop (which only ever loops ove the
bits in a single "unsigned long" anyway), which makes the performance
regression go away.
Reported-and-tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the patch for the group descriptor table corruption during
online resize pointed out by Theodore Tso. The problem was caused by
the fact that the ext4 group descriptor can be either 32 or 64 bytes
long. Only the 64 bytes structure was taken into account.
Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Use max not min to enforce a lower limit on the max I/O size.
This bug was introduced by "fuse: fix max i/o size calculation" (commit
e5d9a0df07).
Thanks to Brian Wang for noticing.
Reported-by: Brian Wang <ywang221@hotmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Szabolcs Szakacsits <szaka@ntfs-3g.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2:
ocfs2: Remove ->hangup() from stack glue operations.
ocfs2: Move the call of ocfs2_hb_ctl into the stack glue.
ocfs2: Move the hb_ctl_path sysctl into the stack glue.
The ->hangup() call was only used to execute ocfs2_hb_ctl. Now that
the generic stack glue code handles this, the underlying stack drivers
don't need to know about it.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Take o2hb_stop() out of the o2cb code and make it part of the generic
stack glue as ocfs2_leave_group(). This also allows us to remove the
ocfs2_get_hb_ctl_path() function - everything to do with hb_ctl is now
part of stackglue.c. o2cb no longer needs a ->hangup() function.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2 needs to call out to the hb_ctl program at unmount for all cluster
stacks. The first step is to move the hb_ctl_path sysctl out of the
o2cb code and into the generic stack glue.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
In commit d20894a237 ("Remove a.out
interpreter support in ELF loader"), Andi removed support for a.out
interpreters from the ELF loader, which was only ever needed for the
transition from a.out to ELF.
This removes the last traces of that support, in particular the
inclusion of <linux/a.out.h>.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We only need it for the /sbin/loader hack for OSF/1 executables, and we
don't want to include it otherwise.
While we're at it, remove the redundant '&& CONFIG_ARCH_SUPPORTS_AOUT'
in the ifdef around that code. It's already dependent on __alpha__, and
CONFIG_ARCH_SUPPORTS_AOUT is hard-coded to 'y' there.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 706047a797, "udf: Fix compilation
warnings when UDF debug is on" inadvertently (I assume) enabled
debugging messages by default for UDF. This patch disables them again.
Signed-off-by: Paul Collins <paul@ondioline.org>
Signed-off-by: Jan Kara <jack@suse.cz>
We were walking right into huge page areas in the pagemap walker, and
calling the pmds pmd_bad() and clearing them.
That leaked huge pages. Bad.
This patch at least works around that for now. It ignores huge pages in
the pagemap walker for the time being, and won't leak those pages.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need this at least for huge page detection for now, because powerpc
needs the vm_area_struct to be able to determine whether a virtual address
is referring to a huge page (its pmd_huge() doesn't work).
It might also come in handy for some of the other users.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
New chmod() allows only acceptable permission, and if not acceptable, it
returns -EPERM. Old one allows even if it can't store permission to on
disk inode. But it seems too strict for users.
E.g. https://bugzilla.redhat.com/show_bug.cgi?id=449080: With new one,
rsync couldn't create the temporary file.
So, this patch allows like old one, but now it doesn't change the
permission if it can't store, and it returns 0.
Also, this patch fixes missing check.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] cifs: fix oops on mount when CONFIG_CIFS_DFS_UPCALL is enabled
[CIFS] Fix hang in mount when negprot causes server to kill tcp session
disable most mode changes on non-unix/non-cifsacl mounts
[CIFS] Correct incorrect obscure open flag
[CIFS] warn if both dynperm and cifsacl mount options specified
silently ignore ownership changes unless unix extensions are enabled or we're faking uid changes
[CIFS] remove trailing whitespace
when creating new inodes, use file_mode/dir_mode exclusively on mount without unix extensions
on non-posix shares, clear write bits in mode when ATTR_READONLY is set
[CIFS] remove unused variables
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: enable barriers by default
jbd2: Fix barrier fallback code to re-lock the buffer head
ext4: Display the journal_async_commit mount option in /proc/mounts
jbd2: If a journal checksum error is detected, propagate the error to ext4
jbd2: Fix memory leak when verifying checksums in the journal
ext4: fix online resize bug
ext4: Fix uninit block group initialization with FLEX_BG
ext4: Fix use of uninitialized data with debug enabled.
use_mm() was changed to use switch_mm() instead of activate_mm(), since
then nobody calls (and nobody should call) activate_mm() with
PF_BORROWED_MM bit set.
As Jeff Dike pointed out, we can also remove the "old != new" check, it is
always true.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Jeff Dike <jdike@addtoit.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/chrisw/lsm-2.6:
capabilities: remain source compatible with 32-bit raw legacy capability support.
LSM: remove stale web site from MAINTAINERS
If the user tries to read from a position that is not a multiple of 8, or
read a number of bytes that is not a multiple of 8, they have passed an
invalid argument to read, for the purpose of reading these files. It's
not an IO error because we didn't encounter any trouble finding the data
they asked for.
Signed-off-by: Thomas Tuttle <ttuttle@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since pagemap is all about examining pages mapped into processes' memory
spaces, it makes sense for kpagecount to return the map counts, not the
reference counts.
Signed-off-by: Thomas Tuttle <ttuttle@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch:
commit e9720acd72
Author: Pavel Emelyanov <xemul@openvz.org>
Date: Fri Mar 7 11:08:40 2008 -0800
[NET]: Make /proc/net a symlink on /proc/self/net (v3)
introduced a /proc/self/net directory without bumping the corresponding
link count for /proc/self.
This patch replaces the static link count initializations with a call that
counts the number of directory entries in the given pid_entry table
whenever it is instantiated, and thus relieves the burden of manually
keeping the two in sync.
[akpm@linux-foundation.org: cleanup]
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a bug when we are trying to verify that the reserve inode's
double indirect blocks point back to the primary gdt blocks. The fix is
obvious, we need to mod the gdb count by the addr's per block. You can
verify this with the following test case
dd if=/dev/zero of=disk1 seek=1024 count=1 bs=100M
losetup /dev/loop1 disk1
pvcreate /dev/loop1
vgcreate loopvg1 /dev/loop1
lvcreate -l 100%VG loopvg1 -n looplv1
mkfs.ext3 -J size=64 -b 1024 /dev/loopvg1/looplv1
mount /dev/loopvg1/looplv1 /mnt/loop
dd if=/dev/zero of=disk2 seek=1024 count=1 bs=50M
losetup /dev/loop2 disk2
pvcreate /dev/loop2
vgextend loopvg1 /dev/loop2
lvextend -l 100%VG /dev/loopvg1/looplv1
resize2fs /dev/loopvg1/looplv1
without this patch the resize2fs fails, with it the resize2fs succeeds.
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The nommu binfmt code uses ksize() for pointers returned from do_mmap()
which is wrong. This converts the call-sites to use the nommu specific
kobjsize() function which works as expected.
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Matt Mackall <mpm@selenic.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a bug in add_to_pagemap. Previously, since pm->out was a char *,
put_user was only copying 1 byte of every PFN, resulting in the top 7
bytes of each PFN not being copied. By requiring that reads be a multiple
of 8 bytes, I can make pm->out and pm->end u64*s instead of char*s, which
makes put_user work properly, and also simplifies the logic in
add_to_pagemap a bit.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Thomas Tuttle <ttuttle@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently even if a task sits in an all-denied cgroup it can still mount
any block device in any mode it wants.
Put a proper check in do_open for block device to prevent this.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Tested-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch introduces memory_read_from_buffer().
The only difference between memory_read_from_buffer() and
simple_read_from_buffer() is which address space the function copies to.
simple_read_from_buffer copies to user space memory.
memory_read_from_buffer copies to normal memory.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Doug Warzecha <Douglas_Warzecha@dell.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: Abhay Salunke <Abhay_Salunke@dell.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Markus Rechberger <markus.rechberger@amd.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Bob Moore <robert.moore@intel.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Len Brown <lenb@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Michael Holzheu <holzheu@de.ibm.com>
Cc: Brian King <brking@us.ibm.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Andrew Vasquez <linux-driver@qlogic.com>
Cc: Seokmann Ju <seokmann.ju@qlogic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Although if people have questions about ARCnet, perhaps it's _better_
for them to be mailing dwmw2@cam.ac.uk about it...
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The page decrypt calls in ecryptfs_write() are both pointless and buggy.
Pointless because ecryptfs_get_locked_page() has already brought the page
up to date, and buggy because prior mmap writes will just be blown away by
the decrypt call.
This patch also removes the declaration of a now-nonexistent function
ecryptfs_write_zeros().
Thanks to Eric Sandeen and David Kleikamp for helping to track this
down.
Eric said:
fsx w/ mmap dies quickly ( < 100 ops) without this, and survives
nicely (to millions of ops+) with it in place.
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following compile error:
CC fs/binfmt_flat.o
In file included from
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c:36:
/home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/flat.h:14:22: error: asm/flat.h: No such file or directory
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c: In function 'create_flat_tables':
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c:124: error: implicit declaration of function 'flat_stack_align'
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c:125: error: implicit declaration of function 'flat_argvp_envp_on_stack'
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c: In function 'calc_reloc':
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c:347: error: implicit declaration of function 'flat_reloc_valid'
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c: In function 'load_flat_file':
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c:479: error: implicit declaration of function 'flat_old_ram_flag'
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c:755: error: implicit declaration of function 'flat_set_persistent'
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c:757: error: implicit declaration of function 'flat_get_relocate_addr'
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c:765: error: implicit declaration of function 'flat_get_addr_from_rp'
/home/bunk/linux/kernel-2.6/git/linux-2.6/fs/binfmt_flat.c:781: error: implicit declaration of function 'flat_put_addr_at_rp'
Reported-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Tested-by: David Howells <dhowells@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Don't trust a length which is greater than the working buffer.
An invalid length could cause overflow when calculating buffer size
for decoding oid.
- An oid length of zero is invalid and allows for an off-by-one error when
decoding oid because the first subid actually encodes first 2 subids.
- A primitive encoding may not have an indefinite length.
Thanks to Wei Wang from McAfee for report.
Cc: Steven French <sfrench@us.ibm.com>
Cc: stable@kernel.org
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__le16 fields used as host-endian.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Steve French <smfrench@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Source code out there hard-codes a notion of what the
_LINUX_CAPABILITY_VERSION #define means in terms of the semantics of the
raw capability system calls capget() and capset(). Its unfortunate, but
true.
Since the confusing header file has been in a released kernel, there is
software that is erroneously using 64-bit capabilities with the semantics
of 32-bit compatibilities. These recently compiled programs may suffer
corruption of their memory when sys_getcap() overwrites more memory than
they are coded to expect, and the raising of added capabilities when using
sys_capset().
As such, this patch does a number of things to clean up the situation
for all. It
1. forces the _LINUX_CAPABILITY_VERSION define to always retain its
legacy value.
2. adopts a new #define strategy for the kernel's internal
implementation of the preferred magic.
3. deprecates v2 capability magic in favor of a new (v3) magic
number. The functionality of v3 is entirely equivalent to v2,
the only difference being that the v2 magic causes the kernel
to log a "deprecated" warning so the admin can find applications
that may be using v2 inappropriately.
[User space code continues to be encouraged to use the libcap API which
protects the application from details like this. libcap-2.10 is the first
to support v3 capabilities.]
Fixes issue reported in https://bugzilla.redhat.com/show_bug.cgi?id=447518.
Thanks to Bojan Smojver for the report.
[akpm@linux-foundation.org: s/depreciate/deprecate/g]
[akpm@linux-foundation.org: be robust about put_user size]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Bojan Smojver <bojan@rexursive.com>
Cc: stable@kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
This patch silences the build warnings concerning o2net_init_nst()
and friends when building without CONFIG_DEBUG_FS enabled.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch silences the build warnings concerning dlm_debug_init()
and friends when building without CONFIG_DEBUG_FS enabled.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch silences the build warnings concerning o2net_debugfs_init()
and friends when building without CONFIG_DEBUG_FS enabled.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The static structure describing the userspace cluster plugin for ocfs2
was named 'user_stack', which is a real pain when people are grep(1)ing
the tree for the program stack object 'user_stack'. Change the name to
something distinct and namespaced.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
splice currently assumes that try_to_release_page() always suceeds,
but it can return failure. If it does, we cannot steal the page.
Acked-by: Mingming Cao <cmm@us.ibm.com
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Splice isn't always incrementing the ppos correctly, which broke
relay splice.
Signed-off-by: Tom Zanussi <zanussi@comcast.net>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Based on Roland's patch. This approach was suggested by Austin Clements
from the very beginning, and then by Linus.
As Austin pointed out, the execing task can be killed by SI_TIMER signal
because exec flushes the signal handlers, but doesn't discard the pending
signals generated by posix timers. Perhaps not a bug, but people find this
surprising. See http://bugzilla.kernel.org/show_bug.cgi?id=10460
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Austin Clements <amdragon+kernelbugzilla@mit.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I can't think of any valid reason for ext4 to not use barriers when
they are available; I believe this is necessary for filesystem
integrity in the face of a volatile write cache on storage.
An administrator who trusts that the cache is sufficiently battery-
backed (and power supplies are sufficiently redundant, etc...)
can always turn it back off again.
SuSE has carried such a patch for ext3 for quite some time now.
Also document the mount option while we're at it.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If the device doesn't support write barriers, the write is retried
without ordered mode. But the buffer head needs to be re-locked or
submit_bh will fail with on BUG(!buffer_locked(bh)).
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
