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* mqueue: lift mnt_want_write() outside ->i_mutex, clean up a bitAl Viro2012-08-181-33/+28
| | | | | | | the way it abuses ->d_fsdata still needs to be killed, but that's a separate story. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch dentry_open() to struct path, make it grab references itselfAl Viro2012-07-231-70/+47
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't pass nameidata * to vfs_create()Al Viro2012-07-141-1/+1
| | | | | | all we want is a boolean flag, same as the method gets now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't pass nameidata to ->create()Al Viro2012-07-141-1/+1
| | | | | | | | boolean "does it have to be exclusive?" flag is passed instead; Local filesystem should just ignore it - the object is guaranteed not to be there yet. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ipc/mqueue: add rbtree node caching supportDoug Ledford2012-05-311-23/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I wrote the first patch that added the rbtree support for message queue insertion, it sped up the case where the queue was very full drastically from the original code. It, however, slowed down the case where the queue was empty (not drastically though). This patch caches the last freed rbtree node struct so we can quickly reuse it when we get a new message. This is the common path for any queue that very frequently goes from 0 to 1 then back to 0 messages in queue. Andrew Morton didn't like that we were doing a GFP_ATOMIC allocation in msg_insert, so this patch attempts to speculatively allocate a new node struct outside of the spin lock when we know we need it, but will still fall back to a GFP_ATOMIC allocation if it has to. Once I added the caching, the necessary various ret = ; spin_unlock gyrations in mq_timedsend were getting pretty ugly, so this also slightly refactors that function to streamline the flow of the code and the function exit. Finally, while working on getting performance back I made sure that all of the node structs were always fully initialized when they were first used, rendering the use of kzalloc unnecessary and a waste of CPU cycles. The net result of all of this is: 1) We will avoid a GFP_ATOMIC allocation when possible, but fall back on it when necessary. 2) We will speculatively allocate a node struct using GFP_KERNEL if our cache is empty (and save the struct to our cache if it's still empty after we have obtained the spin lock). 3) The performance of the common queue empty case has significantly improved and is now much more in line with the older performance for this case. The performance changes are: Old mqueue new mqueue new mqueue + caching queue empty send/recv 305/288ns 349/318ns 310/322ns I don't think we'll ever be able to get the recv performance back, but that's because the old recv performance was a direct result and consequence of the old methods abysmal send performance. The recv path simply must do more so that the send path does not incur such a penalty under higher queue depths. As it turns out, the new caching code also sped up the various queue full cases relative to my last patch. That could be because of the difference between the syscall path in 3.3.4-rc5 and 3.3.4-rc6, or because of the change in code flow in the mq_timedsend routine. Regardless, I'll take it. It wasn't huge, and I *would* say it was within the margin for error, but after many repeated runs what I'm seeing is that the old numbers trend slightly higher (about 10 to 20ns depending on which test is the one running). [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> 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>
* ipc/mqueue: strengthen checks on mqueue creationDoug Ledford2012-05-311-9/+18
| | | | | | | | | | | | | | | | | | | | | We already check the mq attr struct if it's passed in, but now that the admin can set system wide defaults separate from maximums, it's actually possible to set the defaults to something that would overflow. So, if there is no attr struct passed in to the open call, check the default values. While we are at it, simplify mq_attr_ok() by making it return 0 or an error condition, so that way if we add more tests to it later, we have the option of what error should be returned instead of the calling location having to pick a possibly inaccurate error code. [akpm@linux-foundation.org: s/ENOMEM/EOVERFLOW/] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Manfred Spraul <manfred@colorfullife.com> Acked-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>
* ipc/mqueue: correct mq_attr_ok testDoug Ledford2012-05-311-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | While working on the other parts of the mqueue stuff, I noticed that the calculation for overflow in mq_attr_ok didn't actually match reality (this is especially true since my last patch which changed how we account memory slightly). In particular, we used to test for overflow using: msgs * msgsize + msgs * sizeof(struct msg_msg *) That was never really correct because each message we allocate via load_msg() is actually a struct msg_msg followed by the data for the message (and if struct msg_msg + data exceeds PAGE_SIZE we end up allocating struct msg_msgseg structs too, but accounting for them would get really tedious, so let's ignore those...they're only a pointer in size anyway). This patch updates the calculation to be more accurate in regards to maximum possible memory consumption by the mqueue. [akpm@linux-foundation.org: add a local to simplify overflow-checking expression] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Manfred Spraul <manfred@colorfullife.com> Acked-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>
* ipc/mqueue: improve performance of send/recvDoug Ledford2012-05-311-43/+130
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing implementation of the POSIX message queue send and recv functions is, well, abysmal. Even worse than abysmal. I submitted a patch to increase the maximum POSIX message queue limit to 65536 due to customer needs, however, upon looking over the send/recv implementation, I realized that my customer needs help with that too even if they don't know it. The basic problem is that, given the fairly typical use case scenario for a large queue of queueing lots of messages all at the same priority (I verified with my customer that this is indeed what their app does), the msg_insert routine is basically a frikkin' bubble sort. I mean, whoa, that's *so* middle school. OK, OK, to not slam the original author too much, I'm sure they didn't envision a queue depth of 50,000+ messages. No one would think that moving elements in an array, one at a time, and dereferencing each pointer in that array to check priority of the message being pointed too, again one at a time, for 50,000+ times would be good. So let's assume that, as is typical, the users have found a way to break our code simply by using it in a way we didn't envision. Fair enough. "So, just how broken is it?", you ask. I wondered the same thing, so I wrote an app to let me know. It's my next patch. It gave me some interesting results. Here's what it tested: Interference with other apps - In continuous mode, the app just sits there and hits a message queue forever, while you go do something productive on another terminal using other CPUs. You then measure how long it takes you to do that something productive. Then you restart the app in fake continuous mode, and it sits in a tight loop on a CPU while you repeat your tests. The whole point of this is to keep one CPU tied up (so it can't be used in your other work) but in one case tied up hitting the mqueue code so we can see the effect of walking that 65,528 element array one pointer at a time on the global CPU cache. If it's bad, then it will slow down your app on the other CPUs just by polluting cache mercilessly. In the fake case, it will be in a tight loop, but not polluting cache. Testing the mqueue subsystem directly - Here we just run a number of tests to see how the mqueue subsystem performs under different conditions. A couple conditions are known to be worst case for the old system, and some routines, so this tests all of them. So, on to the results already: Subsystem/Test Old New Time to compile linux kernel (make -j12 on a 6 core CPU) Running mqueue test user 49m10.744s user 45m26.294s sys 5m51.924s sys 4m59.894s total 55m02.668s total 50m26.188s Running fake test user 45m32.686s user 45m18.552s sys 5m12.465s sys 4m56.468s total 50m45.151s total 50m15.020s % slowdown from mqueue cache thrashing ~8% ~.5% Avg time to send/recv (in nanoseconds per message) when queue empty 305/288 349/318 when queue full (65528 messages) constant priority 526589/823 362/314 increasing priority 403105/916 495/445 decreasing priority 73420/594 482/409 random priority 280147/920 546/436 Time to fill/drain queue (65528 messages, in seconds) constant priority 17.37/.12 .13/.12 increasing priority 4.14/.14 .21/.18 decreasing priority 12.93/.13 .21/.18 random priority 8.88/.16 .22/.17 So, I think the results speak for themselves. It's possible this implementation could be improved by cacheing at least one priority level in the node tree (that would bring the queue empty performance more in line with the old implementation), but this works and is *so* much better than what we had, especially for the common case of a single priority in use, that further refinements can be in follow on patches. [akpm@linux-foundation.org: fix typo in comment, remove stray semicolon] [levinsasha928@gmail.com: use correct gfp flags in msg_insert] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Manfred Spraul <manfred@colorfullife.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mqueue: separate mqueue default value from maximum valueKOSAKI Motohiro2012-05-311-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b231cca4381e ("message queues: increase range limits") changed mqueue default value when attr parameter is specified NULL from hard coded value to fs.mqueue.{msg,msgsize}_max sysctl value. This made large side effect. When user need to use two mqueue applications 1) using !NULL attr parameter and it require big message size and 2) using NULL attr parameter and only need small size message, app (1) require to raise fs.mqueue.msgsize_max and app (2) consume large memory size even though it doesn't need. Doug Ledford propsed to switch back it to static hard coded value. However it also has a compatibility problem. Some applications might started depend on the default value is tunable. The solution is to separate default value from maximum value. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Doug Ledford <dledford@redhat.com> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Joe Korty <joe.korty@ccur.com> Cc: Amerigo Wang <amwang@redhat.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mqueue: don't use kmalloc with KMALLOC_MAX_SIZEKOSAKI Motohiro2012-05-311-2/+2
| | | | | | | | | | | | | | | | | | | KMALLOC_MAX_SIZE is not a good threshold. It is extremely high and problematic. Unfortunately, some silly drivers depend on this and we can't change it. But any new code needn't use such extreme ugly high order allocations. It brings us awful fragmentation issues and system slowdown. Signed-off-by: KOSAKI Motohiro <mkosaki@jp.fujitsu.com> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Joe Korty <joe.korty@ccur.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Joe Korty <joe.korty@ccur.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/mqueue: update maximums for the mqueue subsystemDoug Ledford2012-05-311-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b231cca4381e ("message queues: increase range limits") changed the maximum size of a message in a message queue from INT_MAX to 8192*128. Unfortunately, we had customers that relied on a size much larger than 8192*128 on their production systems. After reviewing POSIX, we found that it is silent on the maximum message size. We did find a couple other areas in which it was not silent. Fix up the mqueue maximums so that the customer's system can continue to work, and document both the POSIX and real world requirements in ipc_namespace.h so that we don't have this issue crop back up. Also, commit 9cf18e1dd74cd0 ("ipc: HARD_MSGMAX should be higher not lower on 64bit") fiddled with HARD_MSGMAX without realizing that the number was intentionally in place to limit the msg queue depth to one that was small enough to kmalloc an array of pointers (hence why we divided 128k by sizeof(long)). If we wish to meet POSIX requirements, we have no choice but to change our allocation to a vmalloc instead (at least for the large queue size case). With that, it's possible to increase our allowed maximum to the POSIX requirements (or more if we choose). [sfr@canb.auug.org.au: using vmalloc requires including vmalloc.h] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: 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>
* ipc/mqueue: enforce hard limitsDoug Ledford2012-05-311-3/+5
| | | | | | | | | | | | | | | | In two places we don't enforce the hard limits for CAP_SYS_RESOURCE apps. In preparation for making more reasonable hard limits, start enforcing them even on CAP_SYS_RESOURCE. Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/mqueue: switch back to using non-max values on createDoug Ledford2012-05-311-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b231cca4381e ("message queues: increase range limits") changed how we create a queue that does not include an attr struct passed to open so that it creates the queue with whatever the maximum values are. However, if the admin has set the maximums to allow flexibility in creating a queue (aka, both a large size and large queue are allowed, but combined they create a queue too large for the RLIMIT_MSGQUEUE of the user), then attempts to create a queue without an attr struct will fail. Switch back to using acceptable defaults regardless of what the maximums are. Note: so far, we only know of a few applications that rely on this behavior (specifically, set the maximums in /proc, then run the application which calls mq_open() without passing in an attr struct, and the application expects the newly created message queue to have the maximum sizes that were set in /proc used on the mq_open() call, and all of those applications that we know of are actually part of regression test suites that were coded to do something like this: for size in 4096 65536 $((1024 * 1024)) $((16 * 1024 * 1024)); do echo $size > /proc/sys/fs/mqueue/msgsize_max mq_open || echo "Error opening mq with size $size" done These test suites that depend on any behavior like this are broken. The concept that programs should rely upon the system wide maximum in order to get their desired results instead of simply using a attr struct to specify what they want is fundamentally unfriendly programming practice for any multi-tasking OS. Fixing this will break those few apps that we know of (and those app authors recognize the brokenness of their code and the need to fix it). However, the following patch "mqueue: separate mqueue default value" allows a workaround in the form of new knobs for the default msg queue creation parameters for any software out there that we don't already know about that might rely on this behavior at the moment. Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linuxLinus Torvalds2012-05-281-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull writeback tree from Wu Fengguang: "Mainly from Jan Kara to avoid iput() in the flusher threads." * tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: Avoid iput() from flusher thread vfs: Rename end_writeback() to clear_inode() vfs: Move waiting for inode writeback from end_writeback() to evict_inode() writeback: Refactor writeback_single_inode() writeback: Remove wb->list_lock from writeback_single_inode() writeback: Separate inode requeueing after writeback writeback: Move I_DIRTY_PAGES handling writeback: Move requeueing when I_SYNC set to writeback_sb_inodes() writeback: Move clearing of I_SYNC into inode_sync_complete() writeback: initialize global_dirty_limit fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds mm: page-writeback.c: local functions should not be exposed globally
| * vfs: Rename end_writeback() to clear_inode()Jan Kara2012-05-061-1/+1
| | | | | | | | | | | | | | | | | | After we moved inode_sync_wait() from end_writeback() it doesn't make sense to call the function end_writeback() anymore. Rename it to clear_inode() which well says what the function really does - set I_CLEAR flag. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
* | userns: Replace user_ns_map_uid and user_ns_map_gid with from_kuid and from_kgidEric W. Biederman2012-05-031-2/+1
| | | | | | | | | | | | | | These function are no longer needed replace them with their more useful equivalents. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* | mqueue: Explicitly capture the user namespace to send the notification to.Eric W. Biederman2012-04-071-1/+8
|/ | | | | | | | Stop relying on user->user_ns which is going away and instead capture the user_namespace of the process we are supposed to notify. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* switch open-coded instances of d_make_root() to new helperAl Viro2012-03-201-17/+7
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ipc/mqueue: simplify reading msgqueue limitDavidlohr Bueso2012-01-231-2/+1
| | | | | | | | | | Because the current task is being used to get the limit, we can simply use rlimit() instead of task_rlimit(). Signed-off-by: Davidlohr Bueso <dave@gnu.org> Acked-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>
* user namespace: make signal.c respect user namespacesSerge E. Hallyn2012-01-101-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ipc/mqueue.c: for __SI_MESQ, convert the uid being sent to recipient's user namespace. (new, thanks Oleg) __send_signal: convert current's uid to the recipient's user namespace for any siginfo which is not SI_FROMKERNEL (patch from Oleg, thanks again :) do_notify_parent and do_notify_parent_cldstop: map task's uid to parent's user namespace ptrace_signal maps parent's uid into current's user namespace before including in signal to current. IIUC Oleg has argued that this shouldn't matter as the debugger will play with it, but it seems like not converting the value currently being set is misleading. Changelog: Sep 20: Inspired by Oleg's suggestion, define map_cred_ns() helper to simplify callers and help make clear what we are translating (which uid into which namespace). Passing the target task would make callers even easier to read, but we pass in user_ns because current_user_ns() != task_cred_xxx(current, user_ns). Sep 20: As recommended by Oleg, also put task_pid_vnr() under rcu_read_lock in ptrace_signal(). Sep 23: In send_signal(), detect when (user) signal is coming from an ancestor or unrelated user namespace. Pass that on to __send_signal, which sets si_uid to 0 or overflowuid if needed. Oct 12: Base on Oleg's fixup_uid() patch. On top of that, handle all SI_FROMKERNEL cases at callers, because we can't assume sender is current in those cases. Nov 10: (mhelsley) rename fixup_uid to more meaningful usern_fixup_signal_uid Nov 10: (akpm) make the !CONFIG_USER_NS case clearer Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> From: Serge Hallyn <serge.hallyn@canonical.com> Subject: __send_signal: pass q->info, not info, to userns_fixup_signal_uid (v2) Eric Biederman pointed out that passing info is a bug and could lead to a NULL pointer deref to boot. A collection of signal, securebits, filecaps, cap_bounds, and a few other ltp tests passed with this kernel. Changelog: Nov 18: previous patch missed a leading '&' Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> From: Dan Carpenter <dan.carpenter@oracle.com> Subject: ipc/mqueue: lock() => unlock() typo There was a double lock typo introduced in b085f4bd6b21 "user namespace: make signal.c respect user namespaces" Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* switch mq_open() to umode_tAl Viro2012-01-031-1/+1
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* mqueue: propagate umode_tAl Viro2012-01-031-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch ->create() to umode_tAl Viro2012-01-031-2/+2
| | | | | | | | vfs_create() ignores everything outside of 16bit subset of its mode argument; switching it to umode_t is obviously equivalent and it's the only caller of the method Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: fix the stupidity with i_dentry in inode destructorsAl Viro2012-01-031-1/+0
| | | | | | | | | | Seeing that just about every destructor got that INIT_LIST_HEAD() copied into it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once(); the cost of taking it into inode_init_always() will be negligible for pipes and sockets and negative for everything else. Not to mention the removal of boilerplate code from ->destroy_inode() instances... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ... and the same kind of leak for mqueueAl Viro2011-12-091-5/+3
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ipc/mqueue.c: fix wrong use of schedule_hrtimeout_range_clock()Wanlong Gao2011-10-311-2/+2
| | | | | | | | | | | | | Fix the wrong use of schedule_hrtimeout_range_clock() in wq_sleep(), although it is harmless for the syscall mq_timed* now. It was introduced by 9ca7d8e ("mqueue: Convert message queue timeout to use hrtimers"). Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Cc: Carsten Emde <C.Emde@osadl.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/mqueue.c: fix mq_open() return valueJiri Slaby2011-07-261-5/+7
| | | | | | | | | | | | | | | | | | | | | | We return ENOMEM from mqueue_get_inode even when we have enough memory. Namely in case the system rlimit of mqueue was reached. This error propagates to mq_queue and user sees the error unexpectedly. So fix this up to properly return EMFILE as described in the manpage: EMFILE The process already has the maximum number of files and message queues open. instead of: ENOMEM Insufficient memory. With the previous patch we just switch to ERR_PTR/PTR_ERR/IS_ERR error handling here. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/mqueue.c: refactor failure handlingJiri Slaby2011-07-261-56/+57
| | | | | | | | | | | | | | | If new_inode fails to allocate an inode we need only to return with NULL. But now we test the opposite and have all the work in a nested block. So do the opposite to save one indentation level (and remove unnecessary line breaks). This is only a preparation/cleanup for the next patch where we fix up return values from mqueue_get_inode. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: icache RCU free inodesNick Piggin2011-01-071-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* switch get_sb_ns() usersAl Viro2010-10-291-4/+4
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: do not assign default i_ino in new_inodeChristoph Hellwig2010-10-251-0/+1
| | | | | | | | | | | | | | | 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: Al Viro <viro@zeniv.linux.org.uk>
* new helper: ihold()Al Viro2010-10-251-1/+1
| | | | | | Clones an existing reference to inode; caller must already hold one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* llseek: automatically add .llseek fopArnd Bergmann2010-10-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
* switch mqueue to ->evict_inode()Al Viro2010-08-091-9/+7
| | | | | | | ... and since the inodes are never hashed, we can use default ->drop_inode() just fine. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mqueue doesn't need make_bad_inode()Al Viro2010-06-041-1/+0
| | | | | | | It never hashes them anyway and does final iput() immediately afterwards. With ->drop_inode() being generic_delete_inode()... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'timers-for-linus' of ↵Linus Torvalds2010-05-191-49/+25
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clocksource: Add clocksource_register_hz/khz interface posix-cpu-timers: Optimize run_posix_cpu_timers() time: Remove xtime_cache mqueue: Convert message queue timeout to use hrtimers hrtimers: Provide schedule_hrtimeout for CLOCK_REALTIME timers: Introduce the concept of timer slack for legacy timers ntp: Remove tickadj ntp: Make time_adjust static time: Add xtime, wall_to_monotonic to feature-removal-schedule timer: Try to survive timer callback preempt_count leak timer: Split out timer function call timer: Print function name for timer callbacks modifying preemption count time: Clean up warp_clock() cpu-timers: Avoid iterating over all threads in fastpath_timer_check() cpu-timers: Change SIGEV_NONE timer implementation cpu-timers: Return correct previous timer reload value cpu-timers: Cleanup arm_timer() cpu-timers: Simplify RLIMIT_CPU handling
| * Merge branch 'linus' into timers/coreThomas Gleixner2010-05-101-0/+1
| |\ | | | | | | | | | | | | | | | Reason: Further posix_cpu_timer patches depend on mainline changes Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | mqueue: Convert message queue timeout to use hrtimersCarsten Emde2010-04-061-49/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The message queue functions mq_timedsend() and mq_timedreceive() have not yet been converted to use the hrtimer interface. This patch replaces the call to schedule_timeout() by a call to schedule_hrtimeout() and transforms the expiration time from timespec to ktime as required. [ tglx: Fixed whitespace wreckage ] Signed-off-by: Carsten Emde <C.Emde@osadl.org> Tested-by: Pradyumna Sampath <pradysam@gmail.com> Cc: Arjan van de Veen <arjan@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20100402204331.715783034@osadl.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | mqueue: fix kernel BUG caused by double free() on mq_open()André Goddard Rosa2010-05-111-1/+1
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | In case of aborting because we reach the maximum amount of memory which can be allocated to message queues per user (RLIMIT_MSGQUEUE), we would try to free the message area twice when bailing out: first by the error handling code itself, and then later when cleaning up the inode through delete_inode(). Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* ipc: use rlimit helpersJiri Slaby2010-03-121-1/+1
| | | | | | | | | | | | | 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 3e10e716abf3c71bdb5d86b8f507f9e72236c9cd ("resource: add helpers for fetching rlimits") or ACCESS_ONCE if not applicable. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mqueue: fix typo "failues" -> "failures"André Goddard Rosa2010-03-031-1/+1
| | | | | Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mqueue: only set error codes if they are really necessaryAndré Goddard Rosa2010-03-031-27/+50
| | | | | | | ... postponing assignments until they're needed. Doesn't change code size. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mqueue: simplify do_open() error handlingAndré Goddard Rosa2010-03-031-6/+10
| | | | | | | | | | It reduces code size: text data bss dec hex filename 9925 72 16 10013 271d ipc/mqueue-BEFORE.o 9885 72 16 9973 26f5 ipc/mqueue-AFTER.o Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mqueue: apply mathematics distributivity on mq_bytes calculationAndré Goddard Rosa2010-03-031-4/+5
| | | | | | | | | | Code size reduction: text data bss dec hex filename 9941 72 16 10029 272d ipc/mqueue-BEFORE.o 9925 72 16 10013 271d ipc/mqueue-AFTER.o Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mqueue: remove unneeded info->messages initializationAndré Goddard Rosa2010-03-031-8/+5
| | | | | | | | | | | | | ... and abort earlier if we couldn't allocate the message pointers array, avoiding the u->mq_bytes accounting logic. It reduces code size: text data bss dec hex filename 9949 72 16 10037 2735 ipc/mqueue-BEFORE.o 9941 72 16 10029 272d ipc/mqueue-AFTER.o Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mqueue: fix mq_open() file descriptor leak on user-space processesAndré Goddard Rosa2010-03-031-2/+1
| | | | | | | We leak fd on lookup_one_len() failure Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Untangling ima mess, part 2: deal with countersAl Viro2009-12-161-2/+0
| | | | | | | | | * do ima_get_count() in __dentry_open() * stop doing that in followups * move ima_path_check() to right after nameidata_to_filp() * don't bump counters on it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* const: mark remaining super_operations constAlexey Dobriyan2009-09-221-2/+2
| | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* integrity: ima mq_open imbalance msg fixMimi Zohar2009-06-291-0/+2
| | | | | | | | | | | This patch fixes an imbalance message as reported by Sanchin Sant. As we don't need to measure the message queue, just increment the counters. Reported-by: Sanchin Sant <sanchinp@in.ibm.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-12 14:27:45 +0000