- Jan 14, 2011
-
-
Al Viro authored
cgroup can't use simple_lookup(), since that'd override its desired ->d_op. Tested-by:
Li Zefan <lizf@cn.fujitsu.com> Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
-
Li Zefan authored
Commit 2fd6b7f5 ("fs: dcache scale subdirs") forgot to annotate a dentry lock, which caused a lockdep warning. Reported-by:
Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by:
-
- Jan 13, 2011
-
-
Al Viro authored
switching it to s_d_op allows to kill the cgroup_lookup() kludge. Signed-off-by:
-
- Jan 07, 2011
-
-
Nicholas Piggin authored
Reduce some branches and memory accesses in dcache lookup by adding dentry flags to indicate common d_ops are set, rather than having to check them. This saves a pointer memory access (dentry->d_op) in common path lookup situations, and saves another pointer load and branch in cases where we have d_op but not the particular operation. Patched with: git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i Signed-off-by:Nick Piggin <npiggin@kernel.dk>
-
Nicholas Piggin authored
dget_locked was a shortcut to avoid the lazy lru manipulation when we already held dcache_lock (lru manipulation was relatively cheap at that point). However, how that the lru lock is an innermost one, we never hold it at any caller, so the lock cost can now be avoided. We already have well working lazy dcache LRU, so it should be fine to defer LRU manipulations to scan time. Signed-off-by: -
Nicholas Piggin authored
dcache_lock no longer protects anything. remove it. Signed-off-by: -
Nicholas Piggin authored
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't using dcache_lock for these anyway (eg. using i_mutex). Note: if we change the locking rule in future so that ->d_child protection is provided only with ->d_parent->d_lock, it may allow us to reduce some locking. But it would be an exception to an otherwise regular locking scheme, so we'd have to see some good results. Probably not worthwhile. Signed-off-by: -
Nicholas Piggin authored
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a 0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when we start protecting many other dentry members with d_lock. Signed-off-by: -
Nicholas Piggin authored
Change d_delete from a dentry deletion notification to a dentry caching advise, more like ->drop_inode. Require it to be constant and idempotent, and not take d_lock. This is how all existing filesystems use the callback anyway. This makes fine grained dentry locking of dput and dentry lru scanning much simpler. Signed-off-by: -
Nicholas Piggin authored
Switching d_op on a live dentry is racy in general, so avoid it. In this case it is a negative dentry, which is safer, but there are still concurrent ops which may be called on d_op in that case (eg. d_revalidate). So in general a filesystem may not do this. Fix cgroupfs so as not to do this. Signed-off-by:
-
- Oct 29, 2010
-
-
Al Viro authored
Signed-off-by:
-
- Oct 28, 2010
-
-
Evgeny Kuznetsov authored
Function "strcpy" is used without check for maximum allowed source string length and could cause destination string overflow. Check for string length is added before using "strcpy". Function now is return error if source string length is more than a maximum. akpm: presently considered NotABug, but add the check for general future-safeness and robustness. Signed-off-by:
Evgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com> Acked-by:
Paul Menage <menage@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
-
Daniel Lezcano authored
Current behavior: ================= (1) When we mount a cgroup, we can specify the 'all' option which means to enable all the cgroup subsystems. This is the default option when no option is specified. (2) If we want to mount a cgroup with a subset of the supported cgroup subsystems, we have to specify a subsystems name list for the mount option. (3) If we specify another option like 'noprefix' or 'release_agent', the actual code wants the 'all' or a subsystem name option specified also. Not critical but a bit not friendly as we should assume (1) in this case. (4) Logically, the 'all' option is mutually exclusive with a subsystem name, but this is not detected. In other words: succeed : mount -t cgroup -o all,freezer cgroup /cgroup => is it 'all' or 'freezer' ? fails : mount -t cgroup -o noprefix cgroup /cgroup => succeed if we do '-o noprefix,all' The following patches consolidate a bit the mount options check. New behavior: ============= (1) untouched (2) untouched (3) the 'all' option will be by default when specifying other than a subsystem name option (4) raises an error In other words: fails : mount -t cgroup -o all,freezer cgroup /cgroup succeed : mount -t cgroup -o noprefix cgroup /cgroup For the sake of lisibility, the if ... then ... else ... if ... indentation when parsing the options has been changed to: if ... then ... continue fi Signed-off-by:Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by:
Serge E. Hallyn <serge.hallyn@canonical.com> Reviewed-by:
-
Daniel Lezcano authored
The ns_cgroup is a control group interacting with the namespaces. When a new namespace is created, a corresponding cgroup is automatically created too. The cgroup name is the pid of the process who did 'unshare' or the child of 'clone'. This cgroup is tied with the namespace because it prevents a process to escape the control group and use the post_clone callback, so the child cgroup inherits the values of the parent cgroup. Unfortunately, the more we use this cgroup and the more we are facing problems with it: (1) when a process unshares, the cgroup name may conflict with a previous cgroup with the same pid, so unshare or clone return -EEXIST (2) the cgroup creation is out of control because there may have an application creating several namespaces where the system will automatically create several cgroups in his back and let them on the cgroupfs (eg. a vrf based on the network namespace). (3) the mix of (1) and (2) force an administrator to regularly check and clean these cgroups. This patchset removes the ns_cgroup by adding a new flag to the cgroup and the cgroupfs mount option. It enables the copy of the parent cgroup when a child cgroup is created. We can then safely remove the ns_cgroup as this flag brings a compatibility. We have now to manually create and add the task to a cgroup, which is consistent with the cgroup framework. This patch: Sent as an answer to a previous thread around the ns_cgroup. https://lists.linux-foundation.org/pipermail/containers/2009-June/018627.html It adds a control file 'clone_children' for a cgroup. This control file is a boolean specifying if the child cgroup should be a clone of the parent cgroup or not. The default value is 'false'. This flag makes the child cgroup to call the post_clone callback of all the subsystem, if it is available. At present, the cpuset is the only one which had implemented the post_clone callback. The option can be set at mount time by specifying the 'clone_children' mount option. Signed-off-by:Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by:
-
- Oct 26, 2010
-
-
Christoph Hellwig authored
Instead of always assigning an increasing inode number in new_inode move the call to assign it into those callers that actually need it. For now callers that need it is estimated conservatively, that is the call is added to all filesystems that do not assign an i_ino by themselves. For a few more filesystems we can avoid assigning any inode number given that they aren't user visible, and for others it could be done lazily when an inode number is actually needed, but that's left for later patches. Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
Dave Chinner <dchinner@redhat.com> Signed-off-by:
-
- Oct 04, 2010
-
-
Jan Blunck authored
The BKL is only used in remount_fs and get_sb that are both protected by the superblocks s_umount rw_semaphore. Therefore it is safe to remove the BKL entirely. Signed-off-by:
Jan Blunck <jblunck@infradead.org> Signed-off-by:
Arnd Bergmann <arnd@arndb.de>
-
Jan Blunck authored
This patch is a preparation necessary to remove the BKL from do_new_mount(). It explicitly adds calls to lock_kernel()/unlock_kernel() around get_sb/fill_super operations for filesystems that still uses the BKL. I've read through all the code formerly covered by the BKL inside do_kern_mount() and have satisfied myself that it doesn't need the BKL any more. do_kern_mount() is already called without the BKL when mounting the rootfs and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called from various places without BKL: simple_pin_fs(), nfs_do_clone_mount() through nfs_follow_mountpoint(), afs_mntpt_do_automount() through afs_mntpt_follow_link(). Both later functions are actually the filesystems follow_link inode operation. vfs_kern_mount() is calling the specified get_sb function and lets the filesystem do its job by calling the given fill_super function. Therefore I think it is safe to push down the BKL from the VFS to the low-level filesystems get_sb/fill_super operation. [arnd: do not add the BKL to those file systems that already don't use it elsewhere] Signed-off-by:
-
- Sep 10, 2010
-
-
Michael S. Tsirkin authored
Add cgroup_attach_task_all() The existing cgroup_attach_task_current_cg() API is called by a thread to attach another thread to all of its cgroups; this is unsuitable for cases where a privileged task wants to attach itself to the cgroups of a less privileged one, since the call must be made from the context of the target task. This patch adds a more generic cgroup_attach_task_all() API that allows both the source task and to-be-moved task to be specified. cgroup_attach_task_current_cg() becomes a specialization of the more generic new function. [menage@google.com: rewrote changelog] [akpm@linux-foundation.org: address reviewer comments] Signed-off-by:
Michael S. Tsirkin <mst@redhat.com> Tested-by:
Alex Williamson <alex.williamson@redhat.com> Acked-by:
-
- Sep 05, 2010
-
-
Michael S. Tsirkin authored
cgroup_attach_task_current_cg API that have upstream is backwards: we really need an API to attach to the cgroups from another process A to the current one. In our case (vhost), a priveledged user wants to attach it's task to cgroups from a less priveledged one, the API makes us run it in the other task's context, and this fails. So let's make the API generic and just pass in 'from' and 'to' tasks. Add an inline wrapper for cgroup_attach_task_current_cg to avoid breaking bisect. Signed-off-by:
-
- Aug 20, 2010
-
-
Arnd Bergmann authored
Signed-off-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by:
Josh Triplett <josh@joshtriplett.org>
-
- Aug 11, 2010
-
-
Dan Carpenter authored
The original code didn't leave enough space for a NULL terminator. These strings are copied with strcpy() into fixed length buffers in cgroup_root_from_opts(). Signed-off-by:
Dan Carpenter <error27@gmail.com> Acked-by:
Serge E. Hallyn <serge@hallyn.com> Reviewd-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Ben Blum <bblum@andrew.cmu.edu> Signed-off-by:
-
- Aug 05, 2010
-
-
Greg Kroah-Hartman authored
We really shouldn't be asking userspace to create new root filesystems. So follow along with all of the other in-kernel filesystems, and provide a mount point in sysfs. For cgroupfs, this should be in /sys/fs/cgroup/ This change provides that mount point when the cgroup filesystem is registered in the kernel. Acked-by:
Dhaval Giani <dhaval.giani@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Lennart Poettering <lennart@poettering.net> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@suse.de>
-
- Jul 28, 2010
-
-
Sridhar Samudrala authored
Add a new kernel API to attach a task to current task's cgroup in all the active hierarchies. Signed-off-by:
Sridhar Samudrala <sri@us.ibm.com> Signed-off-by:
-
- Jun 04, 2010
-
-
Greg Thelen authored
Child groups should have a greater depth than their parents. Prior to this change, the parent would incorrectly report zero memory usage for child cgroups when use_hierarchy is enabled. test script: mount -t cgroup none /cgroups -o memory cd /cgroups mkdir cg1 echo 1 > cg1/memory.use_hierarchy mkdir cg1/cg11 echo $$ > cg1/cg11/tasks dd if=/dev/zero of=/tmp/foo bs=1M count=1 echo echo CHILD grep cache cg1/cg11/memory.stat echo echo PARENT grep cache cg1/memory.stat echo $$ > tasks rmdir cg1/cg11 cg1 cd / umount /cgroups Using fae9c791, a recent patch that changed alloc_css_id() depth computation, the parent incorrectly reports zero usage: root@ubuntu:~# ./test 1+0 records in 1+0 records out 1048576 bytes (1.0 MB) copied, 0.0151844 s, 69.1 MB/s CHILD cache 1048576 total_cache 1048576 PARENT cache 0 total_cache 0 With this patch, the parent correctly includes child usage: root@ubuntu:~# ./test 1+0 records in 1+0 records out 1048576 bytes (1.0 MB) copied, 0.0136827 s, 76.6 MB/s CHILD cache 1052672 total_cache 1052672 PARENT cache 0 total_cache 1052672 Signed-off-by:
Greg Thelen <gthelen@google.com> Acked-by:
-
- May 27, 2010
-
-
Kirill A. Shutemov authored
Since we are unable to handle an error returned by cftype.unregister_event() properly, let's make the callback void-returning. mem_cgroup_unregister_event() has been rewritten to be a "never fail" function. On mem_cgroup_usage_register_event() we save old buffer for thresholds array and reuse it in mem_cgroup_usage_unregister_event() to avoid allocation. Signed-off-by:
Kirill A. Shutemov <kirill@shutemov.name> Acked-by:
-
- May 12, 2010
-
-
KAMEZAWA Hiroyuki authored
Some callers (in memcontrol.c) calls css_is_ancestor() without rcu_read_lock. Because css_is_ancestor() has to access RCU protected data, it should be under rcu_read_lock(). This makes css_is_ancestor() itself does safe access to RCU protected area. (At least, "root" can have refcnt==0 if it's not an ancestor of "child". So, we need rcu_read_lock().) Signed-off-by:
-
KAMEZAWA Hiroyuki authored
Commit ad4ba375 ("memcg: css_id() must be called under rcu_read_lock()") modifies memcontol.c for fixing RCU check message. But Andrew Morton pointed out that the fix doesn't seems sane and it was just for hidining lockdep messages. This is a patch for do proper things. Checking again, all places, accessing without rcu_read_lock, that commit fixies was intentional.... all callers of css_id() has reference count on it. So, it's not necessary to be under rcu_read_lock(). Considering again, we can use rcu_dereference_check for css_id(). We know css->id is valid if css->refcnt > 0. (css->id never changes and freed after css->refcnt going to be 0.) This patch makes use of rcu_dereference_check() in css_id/depth and remove unnecessary rcu-read-lock added by the commit. Signed-off-by:
-
- May 11, 2010
-
-
Changli Gao authored
epoll should not touch flags in wait_queue_t. This patch introduces a new function __add_wait_queue_exclusive(), for the users, who use wait queue as a LIFO queue. __add_wait_queue_tail_exclusive() is introduced too instead of add_wait_queue_exclusive_locked(). remove_wait_queue_locked() is removed, as it is a duplicate of __remove_wait_queue(), disliked by users, and with less users. Signed-off-by:
Changli Gao <xiaosuo@gmail.com> Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: <containers@lists.linux-foundation.org> LKML-Reference: <1273214006-2979-1-git-send-email-xiaosuo@gmail.com> Signed-off-by:
Ingo Molnar <mingo@elte.hu>
-
- May 04, 2010
-
-
Li Zefan authored
With CONFIG_PROVE_RCU=y, a warning can be triggered: # mount -t cgroup -o memory xxx /mnt # mkdir /mnt/0 ... kernel/cgroup.c:4442 invoked rcu_dereference_check() without protection! ... This is a false-positive. It's safe to directly access parent_css->id. Signed-off-by:
-
Li Zefan authored
with CONFIG_PROVE_RCU=y, a warning can be triggered: # mount -t cgroup -o debug xxx /mnt # cat /proc/$$/cgroup ... kernel/cgroup.c:1649 invoked rcu_dereference_check() without protection! ... This is a false-positive, because cgroup_path() can be called with either rcu_read_lock() held or cgroup_mutex held. Signed-off-by:
-
- Mar 24, 2010
-
-
Li Zefan authored
commit e6a1105b ("cgroups: subsystem module loading interface") and commit c50cc752 ("sched, cgroups: Fix module export") result in duplicate including of module.h Signed-off-by:
-
- Mar 16, 2010
-
-
Thomas Weber authored
[Ss]ytem => [Ss]ystem udpate => update paramters => parameters orginal => original Signed-off-by:
Thomas Weber <swirl@gmx.li> Acked-by:
Randy Dunlap <rdunlap@xenotime.net> Signed-off-by:
Jiri Kosina <jkosina@suse.cz>
-
- Mar 12, 2010
-
-
Kirill A. Shutemov authored
Events should be removed after rmdir of cgroup directory, but before destroying subsystem state objects. Let's take reference to cgroup directory dentry to do that. Signed-off-by:
KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Acked-by:
-
Kirill A. Shutemov authored
Notify userspace about cgroup removing only after rmdir of cgroup directory to avoid race between userspace and kernelspace. eventfd are used to notify about two types of event: - control file-specific, like crossing memory threshold; - cgroup removing. To understand what really happen, userspace can check if the cgroup still exists. To avoid race beetween userspace and kernelspace we have to notify userspace about cgroup removing only after rmdir of cgroup directory. Signed-off-by:
-
Kirill A. Shutemov authored
This patchset introduces eventfd-based API for notifications in cgroups and implements memory notifications on top of it. It uses statistics in memory controler to track memory usage. Output of time(1) on building kernel on tmpfs: Root cgroup before changes: make -j2 506.37 user 60.93s system 193% cpu 4:52.77 total Non-root cgroup before changes: make -j2 507.14 user 62.66s system 193% cpu 4:54.74 total Root cgroup after changes (0 thresholds): make -j2 507.13 user 62.20s system 193% cpu 4:53.55 total Non-root cgroup after changes (0 thresholds): make -j2 507.70 user 64.20s system 193% cpu 4:55.70 total Root cgroup after changes (1 thresholds, never crossed): make -j2 506.97 user 62.20s system 193% cpu 4:53.90 total Non-root cgroup after changes (1 thresholds, never crossed): make -j2 507.55 user 64.08s system 193% cpu 4:55.63 total This patch: Introduce the write-only file "cgroup.event_control" in every cgroup. To register new notification handler you need: - create an eventfd; - open a control file to be monitored. Callbacks register_event() and unregister_event() must be defined for the control file; - write "<event_fd> <control_fd> <args>" to cgroup.event_control. Interpretation of args is defined by control file implementation; eventfd will be woken up by control file implementation or when the cgroup is removed. To unregister notification handler just close eventfd. If you need notification functionality for a control file you have to implement callbacks register_event() and unregister_event() in the struct cftype. [kamezawa.hiroyu@jp.fujitsu.com: Kconfig fix] Signed-off-by:
-
Li Zefan authored
Don't call get_pid_ns() before we locate/alloc the ns. Signed-off-by:
-
Ben Blum authored
Modify the Block I/O cgroup subsystem to be able to be built as a module. As the CFQ disk scheduler optionally depends on blk-cgroup, config options in block/Kconfig, block/Kconfig.iosched, and block/blk-cgroup.h are enhanced to support the new module dependency. Signed-off-by:
Ben Blum <bblum@andrew.cmu.edu> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by:
-
Ben Blum authored
Provides support for unloading modular subsystems. This patch adds a new function cgroup_unload_subsys which is to be used for removing a loaded subsystem during module deletion. Reference counting of the subsystems' modules is moved from once (at load time) to once per attached hierarchy (in parse_cgroupfs_options and rebind_subsystems) (i.e., 0 or 1). Signed-off-by:
-
Ben Blum authored
Add interface between cgroups subsystem management and module loading This patch implements rudimentary module-loading support for cgroups - namely, a cgroup_load_subsys (similar to cgroup_init_subsys) for use as a module initcall, and a struct module pointer in struct cgroup_subsys. Several functions that might be wanted by modules have had EXPORT_SYMBOL added to them, but it's unclear exactly which functions want it and which won't. Signed-off-by:
-
Ben Blum authored
This patch series provides the ability for cgroup subsystems to be compiled as modules both within and outside the kernel tree. This is mainly useful for classifiers and subsystems that hook into components that are already modules. cls_cgroup and blkio-cgroup serve as the example use cases for this feature. It provides an interface cgroup_load_subsys() and cgroup_unload_subsys() which modular subsystems can use to register and depart during runtime. The net_cls classifier subsystem serves as the example for a subsystem which can be converted into a module using these changes. Patch #1 sets up the subsys[] array so its contents can be dynamic as modules appear and (eventually) disappear. Iterations over the array are modified to handle when subsystems are absent, and the dynamic section of the array is protected by cgroup_mutex. Patch #2 implements an interface for modules to load subsystems, called cgroup_load_subsys, similar to cgroup_init_subsys, and adds a module pointer in struct cgroup_subsys. Patch #3 adds a mechanism for unloading modular subsystems, which includes a more advanced rework of the rudimentary reference counting introduced in patch 2. Patch #4 modifies the net_cls subsystem, which already had some module declarations, to be configurable as a module, which also serves as a simple proof-of-concept. Part of implementing patches 2 and 4 involved updating css pointers in each css_set when the module appears or leaves. In doing this, it was discovered that css_sets always remain linked to the dummy cgroup, regardless of whether or not any subsystems are actually bound to it (i.e., not mounted on an actual hierarchy). The subsystem loading and unloading code therefore should keep in mind the special cases where the added subsystem is the only one in the dummy cgroup (and therefore all css_sets need to be linked back into it) and where the removed subsys was the only one in the dummy cgroup (and therefore all css_sets should be unlinked from it) - however, as all css_sets always stay attached to the dummy cgroup anyway, these cases are ignored. Any fix that addresses this issue should also make sure these cases are addressed in the subsystem loading and unloading code. This patch: Make subsys[] able to be dynamically populated to support modular subsystems This patch reworks the way the subsys[] array is used so that subsystems can register themselves after boot time, and enables the internals of cgroups to be able to handle when subsystems are not present or may appear/disappear. Signed-off-by:
-
