Soft limits is a new feature for the memory resource controller, something
similar has existed in the group scheduler in the form of shares. The CPU
controllers interpretation of shares is very different though.
Soft limits are the most useful feature to have for environments where the
administrator wants to overcommit the system, such that only on memory
contention do the limits become active. The current soft limits
implementation provides a soft_limit_in_bytes interface for the memory
controller and not for memory+swap controller. The implementation
maintains an RB-Tree of groups that exceed their soft limit and starts
reclaiming from the group that exceeds this limit by the maximum amount.
This patch:
Add documentation for soft limits
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: 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>
Change the memory cgroup to remove the overhead associated with accounting
all pages in the root cgroup. As a side-effect, we can no longer set a
memory hard limit in the root cgroup.
A new flag to track whether the page has been accounted or not has been
added as well. Flags are now set atomically for page_cgroup,
pcg_default_flags is now obsolete and removed.
[akpm@linux-foundation.org: fix a few documentation glitches]
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alter the ss->can_attach and ss->attach functions to be able to deal with
a whole threadgroup at a time, for use in cgroup_attach_proc. (This is a
pre-patch to cgroup-procs-writable.patch.)
Currently, new mode of the attach function can only tell the subsystem
about the old cgroup of the threadgroup leader. No subsystem currently
needs that information for each thread that's being moved, but if one were
to be added (for example, one that counts tasks within a group) this bit
would need to be reworked a bit to tell the subsystem the right
information.
[hidave.darkstar@gmail.com: fix build]
Signed-off-by: Ben Blum <bblum@google.com>
Signed-off-by: Paul Menage <menage@google.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Changes css_set freeing mechanism to be under RCU
This is a prepatch for making the procs file writable. In order to free the
old css_sets for each task to be moved as they're being moved, the freeing
mechanism must be RCU-protected, or else we would have to have a call to
synchronize_rcu() for each task before freeing its old css_set.
Signed-off-by: Ben Blum <bblum@google.com>
Signed-off-by: Paul Menage <menage@google.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Separates all pidlist allocation requests to a separate function that
judges based on the requested size whether or not the array needs to be
vmalloced or can be gotten via kmalloc, and similar for kfree/vfree.
Signed-off-by: Ben Blum <bblum@google.com>
Signed-off-by: Paul Menage <menage@google.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Previously there was the problem in which two processes from different pid
namespaces reading the tasks or procs file could result in one process
seeing results from the other's namespace. Rather than one pidlist for
each file in a cgroup, we now keep a list of pidlists keyed by namespace
and file type (tasks versus procs) in which entries are placed on demand.
Each pidlist has its own lock, and that the pidlists themselves are passed
around in the seq_file's private pointer means we don't have to touch the
cgroup or its master list except when creating and destroying entries.
Signed-off-by: Ben Blum <bblum@google.com>
Signed-off-by: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
struct cgroup used to have a bunch of fields for keeping track of the
pidlist for the tasks file. Those are now separated into a new struct
cgroup_pidlist, of which two are had, one for procs and one for tasks.
The way the seq_file operations are set up is changed so that just the
pidlist struct gets passed around as the private data.
Interface example: Suppose a multithreaded process has pid 1000 and other
threads with ids 1001, 1002, 1003:
$ cat tasks
1000
1001
1002
1003
$ cat cgroup.procs
1000
$
Signed-off-by: Ben Blum <bblum@google.com>
Signed-off-by: Paul Menage <menage@google.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following series adds a "cgroup.procs" file to each cgroup that
reports unique tgids rather than pids, and allows all threads in a
threadgroup to be atomically moved to a new cgroup.
The subsystem "attach" interface is modified to support attaching whole
threadgroups at a time, which could introduce potential problems if any
subsystem were to need to access the old cgroup of every thread being
moved. The attach interface may need to be revised if this becomes the
case.
Also added is functionality for read/write locking all CLONE_THREAD
fork()ing within a threadgroup, by means of an rwsem that lives in the
sighand_struct, for per-threadgroup-ness and also for sharing a cacheline
with the sighand's atomic count. This scheme should introduce no extra
overhead in the fork path when there's no contention.
The final patch reveals potential for a race when forking before a
subsystem's attach function is called - one potential solution in case any
subsystem has this problem is to hang on to the group's fork mutex through
the attach() calls, though no subsystem yet demonstrates need for an
extended critical section.
This patch:
Revert
commit 096b7fe012
Author: Li Zefan <lizf@cn.fujitsu.com>
AuthorDate: Wed Jul 29 15:04:04 2009 -0700
Commit: Linus Torvalds <torvalds@linux-foundation.org>
CommitDate: Wed Jul 29 19:10:35 2009 -0700
cgroups: fix pid namespace bug
This is in preparation for some clashing cgroups changes that subsume the
original commit's functionaliy.
The original commit fixed a pid namespace bug which Ben Blum fixed
independently (in the same way, but with different code) as part of a
series of patches. I played around with trying to reconcile Ben's patch
series with Li's patch, but concluded that it was simpler to just revert
Li's, given that Ben's patch series contained essentially the same fix.
Signed-off-by: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch removes the restriction that a cgroup hierarchy must have at
least one bound subsystem. The mount option "none" is treated as an
explicit request for no bound subsystems.
A hierarchy with no subsystems can be useful for plain task tracking, and
is also a step towards the support for multiply-bindable subsystems.
As part of this change, the hierarchy id is no longer calculated from the
bitmask of subsystems in the hierarchy (since this is not guaranteed to be
unique) but is allocated via an ida. Reference counts on cgroups from
css_set objects are now taken explicitly one per hierarchy, rather than
one per subsystem.
Example usage:
mount -t cgroup -o none,name=foo cgroup /mnt/cgroup
Based on the "no-op"/"none" subsystem concept proposed by
kamezawa.hiroyu@jp.fujitsu.com
Signed-off-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the cgroups code makes the assumption that the subsystem
pointers in a struct css_set uniquely identify the hierarchy->cgroup
mappings associated with the css_set; and there's no way to directly
identify the associated set of cgroups other than by indirecting through
the appropriate subsystem state pointers.
This patch removes the need for that assumption by adding a back-pointer
from struct cg_cgroup_link object to its associated cgroup; this allows
the set of cgroups to be determined by traversing the cg_links list in
the struct css_set.
Signed-off-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While it's architecturally clean to have the cgroup debug subsystem be
completely independent of the cgroups framework, it limits its usefulness
for debugging the contents of internal data structures. Move the debug
subsystem code into the scope of all the cgroups data structures to make
more detailed debugging possible.
Signed-off-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To simplify referring to cgroup hierarchies in mount statements, and to
allow disambiguation in the presence of empty hierarchies and
multiply-bindable subsystems this patch adds support for naming a new
cgroup hierarchy via the "name=" mount option
A pre-existing hierarchy may be specified by either name or by subsystems;
a hierarchy's name cannot be changed by a remount operation.
Example usage:
# To create a hierarchy called "foo" containing the "cpu" subsystem
mount -t cgroup -oname=foo,cpu cgroup /mnt/cgroup1
# To mount the "foo" hierarchy on a second location
mount -t cgroup -oname=foo cgroup /mnt/cgroup2
Signed-off-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the last unlock sequence consistent with previous unlock sequeue.
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce "-p|--pid <pid>" for walking the process address space. The
default action is to walk raw memory PFNs.
Both the virtual address and physical address of each present pages will
be listed:
# ./tools/vm/page-types -lp $$ | head -3
voffset offset len flags
400 11bebe 1 __RU_lA____M______________________
402 11bebc 1 __RU_lA____M______________________
Note that voffset/offset/len are now showed as hex numbers.
[akpm@linux-foundation.org: coding-style fixes]
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fix the following 'make includecheck' warning:
Documentation/auxdisplay/cfag12864b-example.c: string.h is included more than once.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In "documentation: update Documentation/filesystem/proc.txt and
Documentation/sysctls" (commit 760df93ec) we merged /proc/sys/fs
documentation in Documentation/sysctl/fs.txt and
Documentation/filesystem/proc.txt, but stale file-nr definition
remained.
This patch adds back the right fs-nr definition for 2.6 kernel.
Signed-off-by: Xiaotian Feng<dfeng@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/filesystems/sharedsubtree.txt needs updating because the
mount command in util-linux package is well aware of shared subtree
features now. The patch also fixes two typos in sharedsubtree.txt.
Signed-off-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mount(8) handles shared subtrees just fine, so remove the smount program
from Documentation/filesystems/sharedsubtree.txt.
Fix annoying "Lets" -> "Let's".
Insert space between '#' prompt and "mount" command.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are many similar code in kernel for one object: convert time between
calendar time and broken-down time.
Here is some source I found:
fs/ncpfs/dir.c
fs/smbfs/proc.c
fs/fat/misc.c
fs/udf/udftime.c
fs/cifs/netmisc.c
net/netfilter/xt_time.c
drivers/scsi/ips.c
drivers/input/misc/hp_sdc_rtc.c
drivers/rtc/rtc-lib.c
arch/ia64/hp/sim/boot/fw-emu.c
arch/m68k/mac/misc.c
arch/powerpc/kernel/time.c
arch/parisc/include/asm/rtc.h
...
We can make a common function for this type of conversion, At least we
can get following benefit:
1: Make kernel simple and unify
2: Easy to fix bug in converting code
3: Reduce clone of code in future
For example, I'm trying to make ftrace display walltime,
this patch will make me easy.
This code is based on code from glibc-2.6
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 6bfde05bf5 ("hugetlbfs: allow the creation of files suitable for
MAP_PRIVATE on the vfs internal mount") altered can_do_hugetlb_shm() to
check if a file is being created for shared memory or mmap(). If this
returns false, we then unconditionally call user_shm_lock() triggering a
warning. This block should never be entered for MAP_HUGETLB. This
patch partially reverts the problem and fixes the check.
Signed-off-by: Eric B Munson <ebmunson@us.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
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>
Now that ksm is in mainline it is better to change the default values to
better fit to most of the users.
This patch change the ksm default values to be:
ksm_thread_pages_to_scan = 100 (instead of 200)
ksm_thread_sleep_millisecs = 20 (like before)
ksm_run = KSM_RUN_STOP (instead of KSM_RUN_MERGE - meaning ksm is
disabled by default)
ksm_max_kernel_pages = nr_free_buffer_pages / 4 (instead of 2046)
The important aspect of this patch is: it disables ksm by default, and sets
the number of the kernel_pages that can be allocated to be a reasonable
number.
Signed-off-by: Izik Eidus <ieidus@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix these warnings:
drivers/built-in.o: In function `apanel_remove':
apanel.c:(.text+0x56e852): undefined reference to `led_classdev_unregister'
drivers/built-in.o: In function `apanel_probe':
apanel.c:(.text+0x56eae3): undefined reference to `led_classdev_register'
drivers/built-in.o: In function `acpi_fujitsu_hotkey_add':
fujitsu-laptop.c:(.text+0x5d7647): undefined reference to `led_classdev_register'
fujitsu-laptop.c:(.text+0x5d76b5): undefined reference to `led_classdev_register'
drivers/built-in.o: In function `wbcir_probe':
winbond-cir.c:(.devinit.text+0x5f375): undefined reference to `led_classdev_register'
winbond-cir.c:(.devinit.text+0x5f663): undefined reference to `led_classdev_unregister'
drivers/built-in.o: In function `wbcir_remove':
winbond-cir.c:(.devexit.text+0x7f23): undefined reference to `led_classdev_unregister'
drivers/built-in.o: In function `fujitsu_cleanup':
fujitsu-laptop.c:(.exit.text+0xbe37): undefined reference to `led_classdev_unregister'
fujitsu-laptop.c:(.exit.text+0xbe53): undefined reference to `led_classdev_unregister'
It happens because the new INPUT_WINBOND_CIR driver relies on new-leds
infrastructure - but does not select it in drivers/input/misc/Kconfig.
But it selects LEDS_CLASS, which confuses a number of other drivers into
thinking that all the leds infrastructure is in place.
Fix this by selecting NEW_LEDS as well, like similar drivers do.
Eventually, this whole leds infrastructure complexity should be
cleaned up, it's been going on for years.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: David Härdeman <david@hardeman.nu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The extent relocation code copy file extents one by one when
relocating data block group. This is inefficient if file
extents are small. This patch makes the relocation code copy
file extents in clusters. So we can can make better use of
read-ahead.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
A recent change enforces only one access point to each subvolume. The first
directory entry (the one added when the subvolume/snapshot was created) is
treated as valid access point, all other subvolume links are linked to dummy
empty directories. The dummy directories are temporary inodes that only in
memory, so we can not rename file into them.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
For every hardlink in btrfs, there is a corresponding inode back
reference. All inode back references for hardlinks in a given
directory are stored in single b-tree item. The size of b-tree item
is limited by the size of b-tree leaf, so we can only create limited
number of hardlinks to a given file in a directory.
The original code lacks of the check, it oops if the number of
hardlinks goes over the limit. This patch fixes the issue by adding
check to btrfs_link and btrfs_rename.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Update some fs code to make use of new helper functions introduced
in the previous patch. Should be no significant change in behaviour
(except CIFS now calls send_sig under i_lock, via inode_newsize_ok).
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: linux-nfs@vger.kernel.org
Cc: Trond.Myklebust@netapp.com
Cc: linux-cifs-client@lists.samba.org
Cc: sfrench@samba.org
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Introduce new truncate helpers truncate_pagecache and inode_newsize_ok.
vmtruncate is also consolidated from mm/memory.c and mm/nommu.c and
into mm/truncate.c.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
sys_mount() reads/copies a whole page for its "type" parameter. When
do_mount_root() passes a kernel address that points to an object which is
smaller than a whole page, copy_mount_options() will happily go past this
memory object, possibly dereferencing "wild" pointers that could be in any
state (hence the kmemcheck warning, which shows that parts of the next
page are not even allocated).
(The likelihood of something going wrong here is pretty low -- first of
all this only applies to kernel calls to sys_mount(), which are mostly
found in the boot code. Secondly, I guess if the page was not mapped,
exact_copy_from_user() _would_ in fact handle it correctly because of its
access_ok(), etc. checks.)
But it is much nicer to avoid the dubious reads altogether, by stopping as
soon as we find a NUL byte. Is there a good reason why we can't do
something like this, using the already existing strndup_from_user()?
[akpm@linux-foundation.org: make copy_mount_string() static]
[AV: fix compat mount breakage, which involves undoing akpm's change above]
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: al <al@dizzy.pdmi.ras.ru>
Most call sites of unload_nls() do:
if (nls)
unload_nls(nls);
Check the pointer inside unload_nls() like we do in kfree() and
simplify the call sites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steve French <sfrench@us.ibm.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Petr Vandrovec <vandrove@vc.cvut.cz>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently we held s_umount while a filesystem is frozen, despite that we
might return to userspace and unlock it from a different process. Instead
grab an active reference to keep the file system busy and add an explicit
check for frozen filesystems in remount and reject the remount instead
of blocking on s_umount.
Add a new get_active_super helper to super.c for use by freeze_bdev that
grabs an active reference to a superblock from a given block device.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that we have the freeze count there is not much reason for bd_mount_sem
anymore. The actual freeze/thaw operations are serialized using the
bd_fsfreeze_mutex, and the only other place we take bd_mount_sem is
get_sb_bdev which tries to prevent mounting a filesystem while the block
device is frozen. Instead of add a check for bd_fsfreeze_count and
return -EBUSY if a filesystem is frozen. While that is a change in user
visible behaviour a failing mount is much better for this case rather
than having the mount process stuck uninterruptible for a long time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
the two places inside exofs that where taking the BKL were:
exofs_put_super() - .put_super
and
exofs_sync_fs() - which is .sync_fs and is also called from
.write_super.
Now exofs_sync_fs() is protected from itself by also taking
the sb_lock.
exofs_put_super() directly calls exofs_sync_fs() so there is no
danger between these two either.
In anyway there is absolutely nothing dangerous been done
inside exofs_sync_fs().
Unless there is some subtle race with the actual lifetime of
the super_block in regard to .put_super and some other parts
of the VFS. Which is highly unlikely.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
romfs_fill_super() assumes that romfs_iget() returns NULL when
it fails. romfs_iget() actually returns ERR_PTR(-ve) in that
case...
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add two helpers that allow access to the seq_file's own buffer, but
hide the internal details of seq_files.
This allows easier implementation of special purpose filling
functions. It also cleans up some existing functions which duplicated
the seq_file logic.
Make these inline functions in seq_file.h, as suggested by Al.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
As Johannes Weiner pointed out, one of the range checks in do_sendfile
is redundant and is already checked in rw_verify_area.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Robert Love <rlove@google.com>
Cc: Mandeep Singh Baines <msb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
sb->s_maxbytes is supposed to indicate the maximum size of a file that can
exist on the filesystem. It's declared as an unsigned long long.
Even if a filesystem has no inherent limit that prevents it from using
every bit in that unsigned long long, it's still problematic to set it to
anything larger than MAX_LFS_FILESIZE. There are places in the kernel
that cast s_maxbytes to a signed value. If it's set too large then this
cast makes it a negative number and generally breaks the comparison.
Change s_maxbytes to be loff_t instead. That should help eliminate the
temptation to set it too large by making it a signed value.
Also, add a warning for couple of releases to help catch filesystems that
set s_maxbytes too large. Eventually we can either convert this to a
BUG() or just remove it and in the hope that no one will get it wrong now
that it's a signed value.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Robert Love <rlove@google.com>
Cc: Mandeep Singh Baines <msb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If fiemap_check_ranges is passed a large enough value, then it's
possible that the value would be cast to a signed value for comparison
against s_maxbytes when we change it to loff_t. Make sure that doesn't
happen by explicitly casting s_maxbytes to an unsigned value for the
purposes of comparison.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robert Love <rlove@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mandeep Singh Baines <msb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently all simple_attr.set handlers return 0 on success and negative
codes on error. Fix simple_attr_write() to return these error codes.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
seq_path_root() is returning a return value of successful __d_path()
instead of returning a negative value when mangle_path() failed.
This is not a bug so far because nobody is using return value of
seq_path_root().
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Do a similar optimization as earlier for touch_atime. Getting the lock in
mnt_get_write is relatively costly, so try all avenues to avoid it first.
This patch is careful to still only update inode fields inside the lock
region.
This didn't show up in benchmarks, but it's easy enough to do.
[akpm@linux-foundation.org: fix typo in comment]
[hugh.dickins@tiscali.co.uk: fix inverted test of mnt_want_write_file()]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Valerie Aurora <vaurora@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Some benchmark testing shows touch_atime to be high up in profile logs for
IO intensive workloads. Most likely that's due to the lock in
mnt_want_write(). Unfortunately touch_atime first takes the lock, and
then does all the other tests that could avoid atime updates (like noatime
or relatime).
Do it the other way round -- first try to avoid the update and only then
if that didn't succeed take the lock. That works because none of the
atime avoidance tests rely on locking.
This also eliminates a goto.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Valerie Aurora <vaurora@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Hugetlbfs needs to do special things instead of truncate_inode_pages().
Currently, it copied generic_forget_inode() except for
truncate_inode_pages() call which is asking for trouble (the code there
isn't trivial). So create a separate function generic_detach_inode()
which does all the list magic done in generic_forget_inode() and call
it from hugetlbfs_forget_inode().
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add device-id and inode number for better debugging. This was suggested
by Andreas in one of the threads
http://article.gmane.org/gmane.comp.file-systems.ext4/12062 .
"If anyone has a chance, fixing this error message to be not-useless would
be good... Including the device name and the inode number would help
track down the source of the problem."
Signed-off-by: Manish Katiyar <mkatiyar@gmail.com>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Impact: have simple_read_from_buffer conform to standards
It was brought to my attention by Andrew Morton, Theodore Tso, and H.
Peter Anvin that a read from userspace should only return -EFAULT if
nothing was actually read.
Looking at the simple_read_from_buffer I noticed that this function does
not conform to that rule. This patch fixes that function.
[akpm@linux-foundation.org: simplification suggested by hpa]
[hpa@zytor.com: fix count==0 handling]
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
