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2012-06-01eventfd: change int to __u64 in eventfd_signal()Sha Zhengju2-9/+5
eventfd_ctx->count is an __u64 counter which is allowed to reach ULLONG_MAX. eventfd_write() adds a __u64 value to "count", but the kernel side eventfd_signal() only adds an int value to it. Make them consistent. [akpm@linux-foundation.org: update interface documentation] Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01fs/nls: add Apple NLSVladimir Serbinenko13-1/+6451
HFS has support for NLS. However the relevant NLS tables are missing. Here they are automatically transformed from the tables at unicode.org. Codepages requiring special handling like CJK, RTL or Brahmic ones are not included in this patch. [akpm@linux-foundation.org: add unicode.org copyright and permission notices] Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Clemens Ladisch <clemens@ladisch.de> 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: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01pidns: make killed children autoreapEric W. Biederman1-1/+6
Force SIGCHLD handling to SIG_IGN so that signals are not generated and so that the children autoreap. This increases the parallelize and in general the speed of network namespace shutdown. Note self reaping childrean can exist past zap_pid_ns_processess but they will all be reaped before we allow the pid namespace init task with pid == 1 to be reaped. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Louis Rilling <louis.rilling@kerlabs.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01pidns: use task_active_pid_ns in do_notify_parentEric W. Biederman1-6/+5
Using task_active_pid_ns is more robust because it works even after we have called exit_namespaces. This change allows us to have parent processes that are zombies. Normally a zombie parent processes is crazy and the last thing you would want to have but in the case of not letting the init process of a pid namespace be reaped until all of it's children are dead and reaped a zombie parent process is exactly what we want. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Louis Rilling <louis.rilling@kerlabs.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01rapidio/tsi721: add DMA engine supportAlexandre Bounine4-92/+1050
Adds support for DMA Engine API into Tsi721 mport driver. Includes following changes for Tsi721 driver: - Modifies BDMA register offset definitions to support per-channel handling - Separates BDMA channel reserved for RIO Maintenance requests - Adds DMA Engine callback routines Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Li Yang <leoli@freescale.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01rapidio: add DMA engine support for RIO data transfersAlexandre Bounine5-0/+163
Adds DMA Engine framework support into RapidIO subsystem. Uses DMA Engine DMA_SLAVE interface to generate data transfers to/from remote RapidIO target devices. Introduces RapidIO-specific wrapper for prep_slave_sg() interface with an extra parameter to pass target specific information. Uses scatterlist to describe local data buffer. Address flat data buffer on a remote side. Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Dan Williams <dan.j.williams@intel.com> Acked-by: Vinod Koul <vinod.koul@linux.intel.com> Cc: Li Yang <leoli@freescale.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01ipc/mqueue: add rbtree node caching supportDoug Ledford1-23/+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>
2012-06-01tools/selftests: add mq_perf_testsDoug Ledford3-1/+746
Add the mq_perf_tests tool I used when creating my mq performance patch. Also add a local .gitignore to keep the binaries from showing up in git status output. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Frederic Weisbecker <fweisbec@gmail.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>
2012-06-01ipc/mqueue: strengthen checks on mqueue creationDoug Ledford1-9/+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>
2012-06-01ipc/mqueue: correct mq_attr_ok testDoug Ledford1-3/+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>
2012-06-01ipc/mqueue: improve performance of send/recvDoug Ledford1-43/+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>
2012-06-01selftests: add mq_open_testsDoug Ledford3-1/+501
Add a directory to house POSIX message queue subsystem specific tests. Add first test which checks the operation of mq_open() under various corner conditions. Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Doug Ledford <dledford@redhat.com> Cc: 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: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01mqueue: separate mqueue default value from maximum valueKOSAKI Motohiro4-3/+33
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>
2012-06-01mqueue: don't use kmalloc with KMALLOC_MAX_SIZEKOSAKI Motohiro1-2/+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>
2012-06-01mqueue: revert bump up DFLT_*MAXKOSAKI Motohiro1-3/+3
Mqueue limitation is slightly naieve parameter likes other ipcs because unprivileged user can consume kernel memory by using ipcs. Thus, too aggressive raise bring us security issue. Example, current setting allow evil unprivileged user use 256GB (= 256 * 1024 * 1024*1024) and it's enough large to system will belome unresponsive. Don't do that. Instead, every admin should adjust the knobs for their own systems. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01ipc/mqueue: update maximums for the mqueue subsystemDoug Ledford2-14/+44
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>
2012-06-01ipc/mqueue: enforce hard limitsDoug Ledford1-3/+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>
2012-06-01ipc/mqueue: switch back to using non-max values on createDoug Ledford2-2/+5
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>
2012-06-01ipc/mqueue: cleanup definition names and locationsDoug Ledford2-23/+13
Since commit b231cca4381e ("message queues: increase range limits") on Oct 18, 2008, calls to mq_open() that did not pass in an attribute struct and expected to get default values for the size of the queue and the max message size now get the system wide maximums instead of hardwired defaults like they used to get. This was uncovered when one of the earlier patches in this patch set increased the default system wide maximums at the same time it increased the hard ceiling on the system wide maximums (a customer specifically needed the hard ceiling brought back up, the new ceiling that commit b231cca4381e introduced was too low for their production systems). By increasing the default maximums and not realising they were tied to any attempt to create a message queue without an attribute struct, I had inadvertently made it such that all message queue creation attempts without an attribute struct were failing because the new default maximums would create a queue that exceeded the default rlimit for message queue bytes. As a result, the system wide defaults were brought back down to their previous levels, and the system wide ceilings on the maximums were raised to meet the customer's needs. However, the fact that the no attribute struct behavior of mq_open() could be broken by changing the system wide maximums for message queues was seen as fundamentally broken itself. So we hardwired the no attribute case back like it used to be. But, then we realized that on the very off chance that some piece of software in the wild depended on that behavior, we could work around that issue by adding two new knobs to /proc that allowed setting the defaults for message queues created without an attr struct separately from the system wide maximums. What is not an option IMO is to leave the current behavior in place. No piece of software should ever rely on setting the system wide maximums in order to get a desired message queue. Such a reliance would be so fundamentally multitasking OS unfriendly as to not really be tolerable. Fortunately, we don't know of any software in the wild that uses this except for a regression test program that caught the issue in the first place. If there is though, we have made accommodations with the two new /proc knobs (and that's all the accommodations such fundamentally broken software can be allowed).. This patch: The various defines for minimums and maximums of the sysctl controllable mqueue values are scattered amongst different files and named inconsistently. Move them all into ipc_namespace.h and make them have consistent names. Additionally, make the number of queues per namespace also have a minimum and maximum and use the same sysctl function as the other two settable variables. Signed-off-by: Doug Ledford <dledford@redhat.com> Acked-by: 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>
2012-06-01kexec: export kexec.h to user spacemaximilian attems2-22/+54
Add userspace definitions, guard all relevant kernel structures. While at it document stuff and remove now useless userspace hint. It is easy to add the relevant system call to respective libc's, but it seems pointless to have to duplicate the data structures. This is based on the kexec-tools headers, with the exception of just using int on return (succes or failure) and using size_t instead of 'unsigned long int' for the number of segments argument of kexec_load(). Signed-off-by: maximilian attems <max@stro.at> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Haren Myneni <hbabu@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01kernel/cpu.c: document clear_tasks_mm_cpumask()Anton Vorontsov1-0/+18
Add more comments on clear_tasks_mm_cpumask, plus adds a runtime check: the function is only suitable for offlined CPUs, and if called inappropriately, the kernel should scream aloud. [akpm@linux-foundation.org: tweak comment: s/walks up/walks/, use 80 cols] Suggested-by: Andrew Morton <akpm@linux-foundation.org> Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01um: properly check all process' threads for a live mmAnton Vorontsov1-6/+7
kill_off_processes() might miss a valid process, this is because checking for process->mm is not enough. Process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To catch this we use find_lock_task_mm(), which walks up all threads and returns an appropriate task (with task lock held). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01um: fix possible race on task->mmAnton Vorontsov1-2/+5
Checking for task->mm is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). We can't use get_task_mm()/mmput() pair as mmput() might sleep, so let's take the task lock while we care about its mm. Note that we should also use find_lock_task_mm() to check all process' threads for a valid mm, but for uml we'll do it in a separate patch. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Richard Weinberger <richard@nod.at> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01um: should hold tasklist_lock while traversing processesAnton Vorontsov1-0/+3
Traversing the tasks requires holding tasklist_lock, otherwise it is unsafe. p.s. However, I'm not sure that calling os_kill_ptraced_process() in the atomic context is correct. It seem to work, but please take a closer look. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Richard Weinberger <richard@nod.at> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01blackfin: fix possible deadlock in decode_address()Anton Vorontsov1-3/+3
Oleg Nesterov found an interesting deadlock possibility: > sysrq_showregs_othercpus() does smp_call_function(showacpu) > and showacpu() show_stack()->decode_address(). Now suppose that IPI > interrupts the task holding read_lock(tasklist). To fix this, blackfin should not grab the write_ variant of the tasklist lock, read_ one is enough. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01blackfin: a couple of task->mm handling fixesAnton Vorontsov1-13/+13
The patch fixes two problems: 1. Working with task->mm w/o getting mm or grabing the task lock is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). We can't use get_task_mm()/mmput() pair as mmput() might sleep, so we have to take the task lock while handle its mm. 2. Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To catch this we use find_lock_task_mm(), which walks up all threads and returns an appropriate task (with task lock held). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01sh: use clear_tasks_mm_cpumask()Anton Vorontsov1-6/+1
Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() has the issue fixed, so let's use it. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01powerpc: use clear_tasks_mm_cpumask()Anton Vorontsov1-9/+2
Current CPU hotplug code has some task->mm handling issues: 1. Working with task->mm w/o getting mm or grabing the task lock is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). We can't use get_task_mm()/mmput() pair as mmput() might sleep, so we must take the task lock while handle its mm. 2. Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() has all the issues fixed, so let's use it. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01arm: use clear_tasks_mm_cpumask()Anton Vorontsov1-7/+1
Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() has this issue fixed, so let's use it. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01cpu: introduce clear_tasks_mm_cpumask() helperAnton Vorontsov2-0/+27
Many architectures clear tasks' mm_cpumask like this: read_lock(&tasklist_lock); for_each_process(p) { if (p->mm) cpumask_clear_cpu(cpu, mm_cpumask(p->mm)); } read_unlock(&tasklist_lock); Depending on the context, the code above may have several problems, such as: 1. Working with task->mm w/o getting mm or grabing the task lock is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). 2. Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. This patch implements a small helper function that does things correctly, i.e.: 1. We take the task's lock while whe handle its mm (we can't use get_task_mm()/mmput() pair as mmput() might sleep); 2. To catch exited main thread case, we use find_lock_task_mm(), which walks up all threads and returns an appropriate task (with task lock held). Also, Per Peter Zijlstra's idea, now we don't grab tasklist_lock in the new helper, instead we take the rcu read lock. We can do this because the function is called after the cpu is taken down and marked offline, so no new tasks will get this cpu set in their mm mask. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Richard Weinberger <richard@nod.at> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01fork: call complete_vfork_done() after clearing child_tid and flushing ↵Konstantin Khlebnikov1-3/+7
rss-counters Child should wake up the parent from vfork() only after finishing all operations with shared mm. There is no sense in using CLONE_CHILD_CLEARTID together with CLONE_VFORK, but it looks more accurate now. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01proc/smaps: show amount of nonlinear ptes in vmaKonstantin Khlebnikov1-0/+12
Currently, nonlinear mappings can not be distinguished from ordinary mappings. This patch adds into /proc/pid/smaps line "Nonlinear: <size> kB", where size is amount of nonlinear ptes in vma, this line appears only if VM_NONLINEAR is set. This information may be useful not only for checkpoint/restore project. Requested by Pavel Emelyanov. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01proc/smaps: carefully handle migration entriesKonstantin Khlebnikov1-8/+10
Currently smaps reports migration entries as "swap", as result "swap" can appears in shared mapping. This patch converts migration entries into pages and handles them as usual. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01proc: report file/anon bit in /proc/pid/pagemapKonstantin Khlebnikov2-19/+31
This is an implementation of Andrew's proposal to extend the pagemap file bits to report what is missing about tasks' working set. The problem with the working set detection is multilateral. In the criu (checkpoint/restore) project we dump the tasks' memory into image files and to do it properly we need to detect which pages inside mappings are really in use. The mincore syscall I though could help with this did not. First, it doesn't report swapped pages, thus we cannot find out which parts of anonymous mappings to dump. Next, it does report pages from page cache as present even if they are not mapped, and it doesn't make that has not been cow-ed. Note, that issue with swap pages is critical -- we must dump swap pages to image file. But the issues with file pages are optimization -- we can take all file pages to image, this would be correct, but if we know that a page is not mapped or not cow-ed, we can remove them from dump file. The dump would still be self-consistent, though significantly smaller in size (up to 10 times smaller on real apps). Andrew noticed, that the proc pagemap file solved 2 of 3 above issues -- it reports whether a page is present or swapped and it doesn't report not mapped page cache pages. But, it doesn't distinguish cow-ed file pages from not cow-ed. I would like to make the last unused bit in this file to report whether the page mapped into respective pte is PageAnon or not. [comment stolen from Pavel Emelyanov's v1 patch] Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.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>
2012-06-01procfs: use more apprioriate types when dumping /proc/N/statJan Engelhardt1-2/+2
- use int fpr priority and nice, since task_nice()/task_prio() return that - field 24: get_mm_rss() returns unsigned long Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01proc: pass "fd" by value in /proc/*/{fd,fdinfo} codeAlexey Dobriyan1-4/+4
Pass "fd" directly, not via pointer -- one less memory read. 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>
2012-06-01proc: don't do dummy rcu_read_lock/rcu_read_unlock on error pathAlexey Dobriyan1-6/+7
rcu_read_lock()/rcu_read_unlock() is nop for TINY_RCU, but is not a nop for, say, PREEMPT_RCU. proc_fill_cache() is called without RCU lock, there is no need to lock/unlock on error path, simply jump out of the loop. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01proc: use mm_access() instead of ptrace_may_access()Cong Wang1-5/+2
mm_access() handles this much better, and avoids some race conditions. Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01proc: remove mm_for_maps()Cong Wang4-11/+4
mm_for_maps() is a simple wrapper for mm_access(), and the name is misleading, so just remove it and use mm_access() directly. Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01proc: clean up /proc/<pid>/environ handlingCong Wang1-21/+24
Similar to e268337dfe26 ("proc: clean up and fix /proc/<pid>/mem handling"), move the check of permission to open(), this will simplify read() code. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01stack usage: add pid to warning printk in check_stack_usageTim Bird1-3/+3
In embedded systems, sometimes the same program (busybox) is the cause of multiple warnings. Outputting the pid with the program name in the warning printk helps distinguish which instances of a program are using the stack most. This is a small patch, but useful. Signed-off-by: Tim Bird <tim.bird@am.sony.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01cred: remove task_is_dead() from __task_cred() validationOleg Nesterov2-8/+4
Commit 8f92054e7ca1 ("CRED: Fix __task_cred()'s lockdep check and banner comment"): add the following validation condition: task->exit_state >= 0 to permit the access if the target task is dead and therefore unable to change its own credentials. OK, but afaics currently this can only help wait_task_zombie() which calls __task_cred() without rcu lock. Remove this validation and change wait_task_zombie() to use task_uid() instead. This means we do rcu_read_lock() only to shut up the lockdep, but we already do the same in, say, wait_task_stopped(). task_is_dead() should die, task->exit_state != 0 means that this task has passed exit_notify(), only do_wait-like code paths should use this. Unfortunately, we can't kill task_is_dead() right now, it has already acquired buggy users in drivers/staging. The fix already exists. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01kmod.c: fix kernel-doc warningRandy Dunlap1-1/+1
Warning(kernel/kmod.c:419): No description found for parameter 'depth' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01kmod: move call_usermodehelper_fns() to .c file and unexport all it's helpersBoaz Harrosh2-31/+24
If we move call_usermodehelper_fns() to kmod.c file and EXPORT_SYMBOL it we can avoid exporting all it's helper functions: call_usermodehelper_setup call_usermodehelper_setfns call_usermodehelper_exec And make all of them static to kmod.c Since the optimizer will see all these as a single call site it will inline them inside call_usermodehelper_fns(). So we loose the call to _fns but gain 3 calls to the helpers. (Not that it matters) Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01kmod: convert two call sites to call_usermodehelper_fns()Boaz Harrosh2-21/+11
Both kernel/sys.c && security/keys/request_key.c where inlining the exact same code as call_usermodehelper_fns(); So simply convert these sites to directly use call_usermodehelper_fns(). Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01kmod: unexport call_usermodehelper_freeinfo()Boaz Harrosh2-6/+1
call_usermodehelper_freeinfo() is not used outside of kmod.c. So unexport it, and make it static to kmod.c Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01fat: use fat_msg_ratelimit() in fat__get_entry()Namjae Jeon1-2/+2
If an application tries to lookup (opendir/readdir/stat) 5000 files on a fatfs USB device and the device is unplugged, many message occur, shown below. This makes the application slow. So use the new fat_msg_ratelimit() decrease the messaging rate. #> ./file_lookup_testcase ./files_directory/ usb 2-1.4: USB disconnect, device number 4 FAT-fs (sda1): FAT read failed (blocknr 2631) FAT-fs (sda1): Directory bread(block 396816) failed FAT-fs (sda1): Directory bread(block 396817) failed FAT-fs (sda1): Directory bread(block 396818) failed FAT-fs (sda1): Directory bread(block 396819) failed FAT-fs (sda1): Directory bread(block 396820) failed FAT-fs (sda1): Directory bread(block 396821) failed FAT-fs (sda1): Directory bread(block 396822) failed FAT-fs (sda1): Directory bread(block 396823) failed FAT-fs (sda1): Directory bread(block 406824) failed FAT-fs (sda1): Directory bread(block 406825) failed FAT-fs (sda1): Directory bread(block 406826) failed FAT-fs (sda1): Directory bread(block 406827) failed FAT-fs (sda1): Directory bread(block 406828) failed FAT-fs (sda1): Directory bread(block 406829) failed FAT-fs (sda1): Directory bread(block 406830) failed FAT-fs (sda1): Directory bread(block 406831) failed FAT-fs (sda1): Directory bread(block 417696) failed FAT-fs (sda1): Directory bread(block 417697) failed FAT-fs (sda1): Directory bread(block 417698) failed FAT-fs (sda1): Directory bread(block 417699) failed FAT-fs (sda1): Directory bread(block 417700) failed FAT-fs (sda1): Directory bread(block 417701) failed FAT-fs (sda1): Directory bread(block 417702) failed FAT-fs (sda1): Directory bread(block 417703) failed FAT-fs (sda1): FAT read failed (blocknr 2631) FAT-fs (sda1): Directory bread(block 396816) failed FAT-fs (sda1): Directory bread(block 396817) failed FAT-fs (sda1): Directory bread(block 396818) failed FAT-fs (sda1): Directory bread(block 396819) failed FAT-fs (sda1): Directory bread(block 396820) failed FAT-fs (sda1): Directory bread(block 396821) failed Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Amit Sahrawat <amit.sahrawat83@gmail.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01fat: add fat_msg_ratelimit()Namjae Jeon1-0/+5
Add a fat_msg_ratelimit() to limit the message generation rate. Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Amit Sahrawat <amit.sahrawat83@gmail.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01fat: switch to fsinfo_inodeArtem Bityutskiy2-31/+18
Currently FAT file-system maps the VFS "superblock" abstraction to the FSINFO block. The FSINFO block contains non-essential data about the amount of free clusters and the next free cluster. FAT file-system can always find out this information by scanning the FAT table, but having it in the FSINFO block may speed things up sometimes. So FAT file-system relies on the VFS superblock write-out services to make sure the FSINFO block is written out to the media from time to time. The whole "superblock write-out" VFS infrastructure is served by the 'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and writes out all dirty superblock using the '->write_super()' call-back. But the problem with this thread is that it wastes power by waking up the system every 5 seconds no matter what. So we want to kill it completely and thus, we need to make file-systems to stop using the '->write_super' VFS service, and then remove it together with the kernel thread. This patch switches the FAT FSINFO block management from '->write_super()'/'->s_dirt' to 'fsinfo_inode'/'->write_inode'. Now, instead of setting the 's_dirt' flag, we just mark the special 'fsinfo_inode' inode as dirty and let VFS invoke the '->write_inode' call-back when needed, where we write-out the FSINFO block. This patch also makes sure we do not mark the 'fsinfo_inode' inode as dirty if we are not FAT32 (FAT16 and FAT12 do not have the FSINFO block) or if we are in R/O mode. As a bonus, we can also remove the '->sync_fs()' and '->write_super()' FAT call-back function because they become unneeded. Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01fat: mark superblock as dirty less oftenArtem Bityutskiy1-4/+5
Preparation for further changes. It touches few functions in fatent.c and prevents them from marking the superblock as dirty unnecessarily often. Namely, instead of marking it as dirty in the internal tight loops - do it only once at the end of the functions. And instead of marking it as dirty while holding the FAT table lock, do it outside the lock. The reason for this patch is that marking the superblock as dirty will soon become a little bit heavier operation, so it is cleaner to do this only when it is necessary. Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>