| Age | Commit message (Collapse) | Author |
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Constify struct kset_uevent_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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When sysfs_readdir stops short we now cache the next
sysfs_dirent to return to user space in filp->private_data.
There is no impact on the rest of sysfs by doing this and
in the common case it allows us to pick up exactly where
we left off with no seeking.
Additionally I drop and regrab the sysfs_mutex around
filldir to avoid a page fault abritrarily increasing the
hold time on the sysfs_mutex.
v2: Returned to using INT_MAX as the EOF condition.
seekdir is ambiguous unless all directory entries have
a unique f_pos value.
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=14949
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Adding/Removing a whole array of attributes is very common. Add a standard
utility function to do this with a simple function call, instead of
requiring drivers to open code this.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Fix kernel-doc notation in new seq-file functions and
correct spelling.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This reverts commit a069c266ae5fdfbf5b4aecf2c672413aa33b2504.
It turns ou that not only was it missing a case (XFS) that needed it,
but perhaps more importantly, people sometimes want to enable new
modules that they hadn't had enabled before, and if such a module uses
list_sort(), it can't easily be inserted any more.
So rather than add a "select LIST_SORT" to the XFS case, just leave it
compiled in. It's not all _that_ big, after all, and the inconvenience
isn't worth it.
Requested-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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* git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs:
[LogFS] Change magic number
[LogFS] Remove h_version field
[LogFS] Check feature flags
[LogFS] Only write journal if dirty
[LogFS] Fix bdev erases
[LogFS] Silence gcc
[LogFS] Prevent 64bit divisions in hash_index
[LogFS] Plug memory leak on error paths
[LogFS] Add MAINTAINERS entry
[LogFS] add new flash file system
Fixed up trivial conflict in lib/Kconfig, and a semantic conflict in
fs/logfs/inode.c introduced by write_inode() being changed to use
writeback_control' by commit a9185b41a4f84971b930c519f0c63bd450c4810d
("pass writeback_control to ->write_inode")
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* 'for-linus' of git://oss.sgi.com/xfs/xfs: (21 commits)
xfs: return inode fork offset in bulkstat for fsr
xfs: Increase the default size of the reserved blocks pool
xfs: truncate delalloc extents when IO fails in writeback
xfs: check for more work before sleeping in xfssyncd
xfs: Fix a build warning in xfs_aops.c
xfs: fix locking for inode cache radix tree tag updates
xfs: remove xfs_ipin/xfs_iunpin
xfs: cleanup xfs_iunpin_wait/xfs_iunpin_nowait
xfs: kill xfs_lrw.h
xfs: factor common xfs_trans_bjoin code
xfs: stop passing opaque handles to xfs_log.c routines
xfs: split xfs_bmap_btalloc
xfs: fix xfs_fsblock_t tracing
xfs: fix inode pincount check in fsync
xfs: Non-blocking inode locking in IO completion
xfs: implement optimized fdatasync
xfs: remove wrapper for the fsync file operation
xfs: remove wrappers for read/write file operations
xfs: merge xfs_lrw.c into xfs_file.c
xfs: fix dquota trace format
...
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* 'for-2.6.34' of git://linux-nfs.org/~bfields/linux: (22 commits)
nfsd4: fix minor memory leak
svcrpc: treat uid's as unsigned
nfsd: ensure sockets are closed on error
Revert "sunrpc: move the close processing after do recvfrom method"
Revert "sunrpc: fix peername failed on closed listener"
sunrpc: remove unnecessary svc_xprt_put
NFSD: NFSv4 callback client should use RPC_TASK_SOFTCONN
xfs_export_operations.commit_metadata
commit_metadata export operation replacing nfsd_sync_dir
lockd: don't clear sm_monitored on nsm_reboot_lookup
lockd: release reference to nsm_handle in nlm_host_rebooted
nfsd: Use vfs_fsync_range() in nfsd_commit
NFSD: Create PF_INET6 listener in write_ports
SUNRPC: NFS kernel APIs shouldn't return ENOENT for "transport not found"
SUNRPC: Bury "#ifdef IPV6" in svc_create_xprt()
NFSD: Support AF_INET6 in svc_addsock() function
SUNRPC: Use rpc_pton() in ip_map_parse()
nfsd: 4.1 has an rfc number
nfsd41: Create the recovery entry for the NFSv4.1 client
nfsd: use vfs_fsync for non-directories
...
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Modify uid check in do_coredump so as to not apply it in the case of
pipes.
This just got noticed in testing. The end of do_coredump validates the
uid of the inode for the created file against the uid of the crashing
process to ensure that no one can pre-create a core file with different
ownership and grab the information contained in the core when they
shouldn' tbe able to. This causes failures when using pipes for a core
dumps if the crashing process is not root, which is the uid of the pipe
when it is created.
The fix is simple. Since the check for matching uid's isn't relevant for
pipes (a process can't create a pipe that the uermodehelper code will open
anyway), we can just just skip it in the event ispipe is non-zero
Reverts a pipe-affecting change which was accidentally made in
: commit c46f739dd39db3b07ab5deb4e3ec81e1c04a91af
: Author: Ingo Molnar <mingo@elte.hu>
: AuthorDate: Wed Nov 28 13:59:18 2007 +0100
: Commit: Linus Torvalds <torvalds@woody.linux-foundation.org>
: CommitDate: Wed Nov 28 10:58:01 2007 -0800
:
: vfs: coredumping fix
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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User visible change.
do_coredump() kills all threads which share the same ->mm but only the
coredumping process gets the proper exit_code. Other tasks which share
the same ->mm die "silently" and return status == 0 to parent.
This is historical behaviour, not actually a bug. But I think Frank
Heckenbach rightly dislikes the current behaviour. Simple test-case:
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <sys/wait.h>
int main(void)
{
int stat;
if (!fork()) {
if (!vfork())
kill(getpid(), SIGQUIT);
}
wait(&stat);
printf("stat=%x\n", stat);
return 0;
}
Before this patch it prints "stat=0" despite the fact the child was killed
by SIGQUIT. After this patch the output is "stat=3" which obviously makes
more sense.
Even with this patch, only the task which originates the coredumping gets
"|= 0x80" if the core was actually dumped, but at least the coredumping
signal is visible to do_wait/etc.
Reported-by: Frank Heckenbach <f.heckenbach@fh-soft.de>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pass mm->flags as a coredump parameter for consistency.
---
1787 if (mm->core_state || !get_dumpable(mm)) { <- (1)
1788 up_write(&mm->mmap_sem);
1789 put_cred(cred);
1790 goto fail;
1791 }
1792
[...]
1798 if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ <-(2)
1799 flag = O_EXCL; /* Stop rewrite attacks */
1800 cred->fsuid = 0; /* Dump root private */
1801 }
---
Since dumpable bits are not protected by lock, there is a chance to change
these bits between (1) and (2).
To solve this issue, this patch copies mm->flags to
coredump_params.mm_flags at the beginning of do_coredump() and uses it
instead of get_dumpable() while dumping core.
This copy is also passed to binfmt->core_dump, since elf*_core_dump() uses
dump_filter bits in mm->flags.
[akpm@linux-foundation.org: fix merge]
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
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>
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The current ELF dumper implementation can produce broken corefiles if
program headers exceed 65535. This number is determined by the number of
vmas which the process have. In particular, some extreme programs may use
more than 65535 vmas. (If you google max_map_count, you can find some
users facing this problem.) This kind of program never be able to generate
correct coredumps.
This patch implements ``extended numbering'' that uses sh_info field of
the first section header instead of e_phnum field in order to represent
upto 4294967295 vmas.
This is supported by
AMD64-ABI(http://www.x86-64.org/documentation.html) and
Solaris(http://docs.sun.com/app/docs/doc/817-1984/).
Of course, we are preparing patches for gdb and binutils.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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By the next patch, elf_core_dump() and elf_fdpic_core_dump() will support
extended numbering and so will produce the corefiles with section header
table in a special case.
The problem is the process of writing a file header offset of the section
header table into e_shoff field of the ELF header. ELF header is
positioned at the beginning of the corefile, while section header at the
end. So, we need to take which of the following ways:
1. Seek backward to retry writing operation for ELF header
after writing process for a whole part
2. Make offset calculation process and writing process
totally sequential
The clause 1. is not always possible: one cannot assume that file system
supports seek function. Consider the no_llseek case.
Therefore, this patch adopts the clause 2.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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elf_core_dump() and elf_fdpic_core_dump() use #ifdef and the corresponding
macro for hiding _multiline_ logics in functions. This patch removes
#ifdef and replaces ELF_CORE_EXTRA_* by corresponding functions. For
architectures not implemeonting ELF_CORE_EXTRA_*, we use weak functions in
order to reduce a range of modification.
This cleanup is for my next patches, but I think this cleanup itself is
worth doing regardless of my firnal purpose.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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My next patch will replace ELF_CORE_EXTRA_* macros by functions, putting
them into other newly created *.c files. Then, each files will contain
dump_write(), where each pair of binfmt_*.c and elfcore.c should be the
same. So, this patch moves them into a header file with dump_seek().
Also, the patch deletes confusing DUMP_WRITE macros in each files.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The current ELF dumper can produce broken corefiles if program headers
exceed 65535. In particular, the program in 64-bit environment often
demands more than 65535 mmaps. If you google max_map_count, then you can
find many users facing this problem.
Solaris has already dealt with this issue, and other OSes have also
adopted the same method as in Solaris. Currently, Sun's document and AMD
64 ABI include the description for the extension, where they call the
extension Extended Numbering. See Reference for further information.
I believe that linux kernel should adopt the same way as they did, so I've
written this patch.
I am also preparing for patches of GDB and binutils.
How to fix
==========
In new dumping process, there are two cases according to weather or
not the number of program headers is equal to or more than 65535.
- if less than 65535, the produced corefile format is exactly the same
as the ordinary one.
- if equal to or more than 65535, then e_phnum field is set to newly
introduced constant PN_XNUM(0xffff) and the actual number of program
headers is set to sh_info field of the section header at index 0.
Compatibility Concern
=====================
* As already mentioned in Summary, Sun and AMD64 has already adopted
this. See Reference.
* There are four combinations according to whether kernel and userland
tools are respectively modified or not. The next table summarizes
shortly for each combination.
---------------------------------------------
Original Kernel | Modified Kernel
---------------------------------------------
< 65535 | >= 65535 | < 65535 | >= 65535
-------------------------------------------------------------
Original Tools | OK | broken | OK | broken (#)
-------------------------------------------------------------
Modified Tools | OK | broken | OK | OK
-------------------------------------------------------------
Note that there is no case that `OK' changes to `broken'.
(#) Although this case remains broken, O-M behaves better than
O-O. That is, while in O-O case e_phnum field would be extremely
small due to integer overflow, in O-M case it is guaranteed to be at
least 65535 by being set to PN_XNUM(0xFFFF), much closer to the
actual correct value than the O-O case.
Test Program
============
Here is a test program mkmmaps.c that is useful to produce the
corefile with many mmaps. To use this, please take the following
steps:
$ ulimit -c unlimited
$ sysctl vm.max_map_count=70000 # default 65530 is too small
$ sysctl fs.file-max=70000
$ mkmmaps 65535
Then, the program will abort and a corefile will be generated.
If failed, there are two cases according to the error message
displayed.
* ``out of memory'' means vm.max_map_count is still smaller
* ``too many open files'' means fs.file-max is still smaller
So, please change it to a larger value, and then retry it.
mkmmaps.c
==
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
int main(int argc, char **argv)
{
int maps_num;
if (argc < 2) {
fprintf(stderr, "mkmmaps [number of maps to be created]\n");
exit(1);
}
if (sscanf(argv[1], "%d", &maps_num) == EOF) {
perror("sscanf");
exit(2);
}
if (maps_num < 0) {
fprintf(stderr, "%d is invalid\n", maps_num);
exit(3);
}
for (; maps_num > 0; --maps_num) {
if (MAP_FAILED == mmap((void *)NULL, (size_t) 1, PROT_READ,
MAP_SHARED | MAP_ANONYMOUS, (int) -1,
(off_t) NULL)) {
perror("mmap");
exit(4);
}
}
abort();
{
char buffer[128];
sprintf(buffer, "wc -l /proc/%u/maps", getpid());
system(buffer);
}
return 0;
}
Tested on i386, ia64 and um/sys-i386.
Built on sh4 (which covers fs/binfmt_elf_fdpic.c)
References
==========
- Sun microsystems: Linker and Libraries.
Part No: 817-1984-17, September 2008.
URL: http://docs.sun.com/app/docs/doc/817-1984
- System V ABI AMD64 Architecture Processor Supplement
Draft Version 0.99., May 11, 2009.
URL: http://www.x86-64.org/
This patch:
There are three different definitions for dump_seek() functions in
binfmt_aout.c, binfmt_elf.c and binfmt_elf_fdpic.c, respectively. The
only for binfmt_elf.c.
My next patch will move dump_seek() into a header file in order to share
the same implementations for dump_write() and dump_seek(). As the first
step, this patch unify these three definitions for dump_seek() by applying
the past commits that have been applied only for binfmt_elf.c.
Specifically, the modification made here is part of the following commits:
* d025c9db7f31fc0554ce7fb2dfc78d35a77f3487
* 7f14daa19ea36b200d237ad3ac5826ae25360461
This patch does not change a shape of corefiles.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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* warn if creation goes on to non-existent directory
* warn if removal goes on from non-existing directory
* warn if non-existing proc entry is removed
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
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>
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remove_proc_entry() does
lock
lookup parent
unlock
lock
unlink proc entry from lists
unlock
which can be made bit more correct by doing parent translation + unlink
without dropping lock.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
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>
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fs/compat_ioctl.c: In function 'do_ioctl_trans':
fs/compat_ioctl.c:534: warning: 'karg' may be used uninitialized in this function
fs/compat_ioctl.c:533: warning: 'kcmd' may be used uninitialized in this function
fs/compat_ioctl.c:656: warning: 'ret' may be used uninitialized in this function
Reduces text size by 44 bytes.
If someone calls one of these functions with an unexpected argument, the
code's buggy as-is.
Amerigo Wang <amwang@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Build list_sort() only for configs that need it -- those that don't save
~581 bytes (i386).
Signed-off-by: Don Mullis <don.mullis@gmail.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently we create the initial stack based on the PAGE_SIZE. This is
unnecessary.
This creates this initial stack independent of the PAGE_SIZE.
It also bumps up the number of 4k pages allocated from 20 to 32, to
align with 64K page systems.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: Helge Deller <deller@gmx.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Make sure compiler won't do weird things with limits. E.g. fetching them
twice may return 2 different values after writable limits are implemented.
I.e. either use rlimit helpers added in commit 3e10e716abf3 ("resource:
add helpers for fetching rlimits") or ACCESS_ONCE if not applicable.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The old anon_vma code can lead to scalability issues with heavily forking
workloads. Specifically, each anon_vma will be shared between the parent
process and all its child processes.
In a workload with 1000 child processes and a VMA with 1000 anonymous
pages per process that get COWed, this leads to a system with a million
anonymous pages in the same anon_vma, each of which is mapped in just one
of the 1000 processes. However, the current rmap code needs to walk them
all, leading to O(N) scanning complexity for each page.
This can result in systems where one CPU is walking the page tables of
1000 processes in page_referenced_one, while all other CPUs are stuck on
the anon_vma lock. This leads to catastrophic failure for a benchmark
like AIM7, where the total number of processes can reach in the tens of
thousands. Real workloads are still a factor 10 less process intensive
than AIM7, but they are catching up.
This patch changes the way anon_vmas and VMAs are linked, which allows us
to associate multiple anon_vmas with a VMA. At fork time, each child
process gets its own anon_vmas, in which its COWed pages will be
instantiated. The parents' anon_vma is also linked to the VMA, because
non-COWed pages could be present in any of the children.
This reduces rmap scanning complexity to O(1) for the pages of the 1000
child processes, with O(N) complexity for at most 1/N pages in the system.
This reduces the average scanning cost in heavily forking workloads from
O(N) to 2.
The only real complexity in this patch stems from the fact that linking a
VMA to anon_vmas now involves memory allocations. This means vma_adjust
can fail, if it needs to attach a VMA to anon_vma structures. This in
turn means error handling needs to be added to the calling functions.
A second source of complexity is that, because there can be multiple
anon_vmas, the anon_vma linking in vma_adjust can no longer be done under
"the" anon_vma lock. To prevent the rmap code from walking up an
incomplete VMA, this patch introduces the VM_LOCK_RMAP VMA flag. This bit
flag uses the same slot as the NOMMU VM_MAPPED_COPY, with an ifdef in mm.h
to make sure it is impossible to compile a kernel that needs both symbolic
values for the same bitflag.
Some test results:
Without the anon_vma changes, when AIM7 hits around 9.7k users (on a test
box with 16GB RAM and not quite enough IO), the system ends up running
>99% in system time, with every CPU on the same anon_vma lock in the
pageout code.
With these changes, AIM7 hits the cross-over point around 29.7k users.
This happens with ~99% IO wait time, there never seems to be any spike in
system time. The anon_vma lock contention appears to be resolved.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We'll introduce FMODE_RANDOM which will be runtime modified. So protect
all runtime modification to f_mode with f_lock to avoid races.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@kernel.org> [2.6.33.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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A frequent questions from users about memory management is what numbers of
swap ents are user for processes. And this information will give some
hints to oom-killer.
Besides we can count the number of swapents per a process by scanning
/proc/<pid>/smaps, this is very slow and not good for usual process
information handler which works like 'ps' or 'top'. (ps or top is now
enough slow..)
This patch adds a counter of swapents to mm_counter and update is at each
swap events. Information is exported via /proc/<pid>/status file as
[kamezawa@bluextal memory]$ cat /proc/self/status
Name: cat
State: R (running)
Tgid: 2910
Pid: 2910
PPid: 2823
TracerPid: 0
Uid: 500 500 500 500
Gid: 500 500 500 500
FDSize: 256
Groups: 500
VmPeak: 82696 kB
VmSize: 82696 kB
VmLck: 0 kB
VmHWM: 432 kB
VmRSS: 432 kB
VmData: 172 kB
VmStk: 84 kB
VmExe: 48 kB
VmLib: 1568 kB
VmPTE: 40 kB
VmSwap: 0 kB <=============== this.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Considering the nature of per mm stats, it's the shared object among
threads and can be a cache-miss point in the page fault path.
This patch adds per-thread cache for mm_counter. RSS value will be
counted into a struct in task_struct and synchronized with mm's one at
events.
Now, in this patch, the event is the number of calls to handle_mm_fault.
Per-thread value is added to mm at each 64 calls.
rough estimation with small benchmark on parallel thread (2threads) shows
[before]
4.5 cache-miss/faults
[after]
4.0 cache-miss/faults
Anyway, the most contended object is mmap_sem if the number of threads grows.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Presently, per-mm statistics counter is defined by macro in sched.h
This patch modifies it to
- defined in mm.h as inlinf functions
- use array instead of macro's name creation.
This patch is for reducing patch size in future patch to modify
implementation of per-mm counter.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Rename for_each_bit to for_each_set_bit in the kernel source tree. To
permit for_each_clear_bit(), should that ever be added.
The patch includes a macro to map the old for_each_bit() onto the new
for_each_set_bit(). This is a (very) temporary thing to ease the migration.
[akpm@linux-foundation.org: add temporary for_each_bit()]
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We managed to lose O_DIRECTORY testing due to a stupid typo in commit
1f36f774b2 ("Switch !O_CREAT case to use of do_last()")
Reported-by: Walter Sheets <w41ter@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Many changes were made during development that could result in old
versions of mklogfs and the kernel code being subtly incompatible.
Not being a friend of subtleties, I hereby change the magic number.
Any old version of mklogfs is now guaranteed to fail.
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Incompatible change: h_compr is moved up so the padding is all in one chunk.
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git://git.linux-nfs.org/projects/trondmy/nfs-2.6
* 'nfs-for-2.6.34' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (44 commits)
NFS: Remove requirement for inode->i_mutex from nfs_invalidate_mapping
NFS: Clean up nfs_sync_mapping
NFS: Simplify nfs_wb_page()
NFS: Replace __nfs_write_mapping with sync_inode()
NFS: Simplify nfs_wb_page_cancel()
NFS: Ensure inode is always marked I_DIRTY_DATASYNC, if it has unstable pages
NFS: Run COMMIT as an asynchronous RPC call when wbc->for_background is set
NFS: Reduce the number of unnecessary COMMIT calls
NFS: Add a count of the number of unstable writes carried by an inode
NFS: Cleanup - move nfs_write_inode() into fs/nfs/write.c
nfs41 fix NFS4ERR_CLID_INUSE for exchange id
NFS: Fix an allocation-under-spinlock bug
SUNRPC: Handle EINVAL error returns from the TCP connect operation
NFSv4.1: Various fixes to the sequence flag error handling
nfs4: renewd renew operations should take/put a client reference
nfs41: renewd sequence operations should take/put client reference
nfs: prevent backlogging of renewd requests
nfs: kill renewd before clearing client minor version
NFS: Make close(2) asynchronous when closing NFS O_DIRECT files
NFS: Improve NFS iostat byte count accuracy for writes
...
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git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
fs/9p: Add hardlink support to .u extension
9P2010.L handshake: .L protocol negotiation
9P2010.L handshake: Remove "dotu" variable
9P2010.L handshake: Add mount option
9P2010.L handshake: Add VFS flags
net/9p: Handle mount errors correctly.
net/9p: Remove MAX_9P_CHAN limit
net/9p: Add multi channel support.
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git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (33 commits)
quota: stop using QUOTA_OK / NO_QUOTA
dquot: cleanup dquot initialize routine
dquot: move dquot initialization responsibility into the filesystem
dquot: cleanup dquot drop routine
dquot: move dquot drop responsibility into the filesystem
dquot: cleanup dquot transfer routine
dquot: move dquot transfer responsibility into the filesystem
dquot: cleanup inode allocation / freeing routines
dquot: cleanup space allocation / freeing routines
ext3: add writepage sanity checks
ext3: Truncate allocated blocks if direct IO write fails to update i_size
quota: Properly invalidate caches even for filesystems with blocksize < pagesize
quota: generalize quota transfer interface
quota: sb_quota state flags cleanup
jbd: Delay discarding buffers in journal_unmap_buffer
ext3: quota_write cross block boundary behaviour
quota: drop permission checks from xfs_fs_set_xstate/xfs_fs_set_xquota
quota: split out compat_sys_quotactl support from quota.c
quota: split out netlink notification support from quota.c
quota: remove invalid optimization from quota_sync_all
...
Fixed trivial conflicts in fs/namei.c and fs/ufs/inode.c
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For regular file and directories we put the link
count in th extension field in a tagged string format.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
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Removes 'dotu' variable and make everything dependent
on 'proto_version' field.
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
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Add 9P2000.u and 9P2010.L protocol flags to V9FS VFS
This patch adds 9P2000.u and 9P2010.L protocol flags into V9FS VFS side code
and removes the single flag used for 'extended'.
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
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Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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Remove the redundant call to filemap_write_and_wait().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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Now that we have correct COMMIT semantics in writeback_single_inode, we can
reduce and simplify nfs_wb_all(). Also replace nfs_wb_nocommit() with a
call to filemap_write_and_wait(), which doesn't need to hold the
inode->i_mutex.
With that done, we can eliminate nfs_write_mapping() altogether.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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In all cases we should be able to just remove the request and call
cancel_dirty_page().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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Since nfs_scan_list() doesn't wait for locked pages, we have a race in
which it is possible to end up with an inode that needs to send a COMMIT,
but which does not have the I_DIRTY_DATASYNC flag set.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
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If the caller is doing a non-blocking flush, and there are still writebacks
pending on the wire, we can usually defer the COMMIT call until those
writes are done.
Also ensure that we honour the wbc->nonblocking flag.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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In order to know when we should do opportunistic commits of the unstable
writes, when the VM is doing a background flush, we add a field to count
the number of unstable writes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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The sole purpose of nfs_write_inode is to commit unstable writes, so
move it into fs/nfs/write.c, and make nfs_commit_inode static.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'write_inode2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
pass writeback_control to ->write_inode
make sure data is on disk before calling ->write_inode
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
Switch !O_CREAT case to use of do_last()
Get rid of symlink body copying
Finish pulling of -ESTALE handling to upper level in do_filp_open()
Turn do_link spaghetty into a normal loop
Unify exits in O_CREAT handling
Kill is_link argument of do_last()
Pull handling of LAST_BIND into do_last(), clean up ok: part in do_filp_open()
Leave mangled flag only for setting nd.intent.open.flag
Get rid of passing mangled flag to do_last()
Don't pass mangled open_flag to finish_open()
pull more into do_last()
bail out with ELOOP earlier in do_link loop
pull the common predecessors into do_last()
postpone __putname() until after do_last()
unroll do_last: loop in do_filp_open()
Shift releasing nd->root from do_last() to its caller
gut do_filp_open() a bit more (do_last separation)
beginning to untangle do_filp_open()
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