path: root/fs/ioprio.c
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2012-05-30Merge branch 'for-3.5/core' of git://git.kernel.dk/linux-blockLinus Torvalds
Merge block/IO core bits from Jens Axboe: "This is a bit bigger on the core side than usual, but that is purely because we decided to hold off on parts of Tejun's submission on 3.4 to give it a bit more time to simmer. As a consequence, it's seen a long cycle in for-next. It contains: - Bug fix from Dan, wrong locking type. - Relax splice gifting restriction from Eric. - A ton of updates from Tejun, primarily for blkcg. This improves the code a lot, making the API nicer and cleaner, and also includes fixes for how we handle and tie policies and re-activate on switches. The changes also include generic bug fixes. - A simple fix from Vivek, along with a fix for doing proper delayed allocation of the blkcg stats." Fix up annoying conflict just due to different merge resolution in Documentation/feature-removal-schedule.txt * 'for-3.5/core' of git://git.kernel.dk/linux-block: (92 commits) blkcg: tg_stats_alloc_lock is an irq lock vmsplice: relax alignement requirements for SPLICE_F_GIFT blkcg: use radix tree to index blkgs from blkcg blkcg: fix blkcg->css ref leak in __blkg_lookup_create() block: fix elvpriv allocation failure handling block: collapse blk_alloc_request() into get_request() blkcg: collapse blkcg_policy_ops into blkcg_policy blkcg: embed struct blkg_policy_data in policy specific data blkcg: mass rename of blkcg API blkcg: style cleanups for blk-cgroup.h blkcg: remove blkio_group->path[] blkcg: blkg_rwstat_read() was missing inline blkcg: shoot down blkgs if all policies are deactivated blkcg: drop stuff unused after per-queue policy activation update blkcg: implement per-queue policy activation blkcg: add request_queue->root_blkg blkcg: make request_queue bypassing on allocation blkcg: make sure blkg_lookup() returns %NULL if @q is bypassing blkcg: make blkg_conf_prep() take @pol and return with queue lock held blkcg: remove static policy ID enums ...
2012-05-03userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfsEric W. Biederman
Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-05-03userns: Store uid and gid values in struct cred with kuid_t and kgid_t typesEric W. Biederman
cred.h and a few trivial users of struct cred are changed. The rest of the users of struct cred are left for other patches as there are too many changes to make in one go and leave the change reviewable. If the user namespace is disabled and CONFIG_UIDGID_STRICT_TYPE_CHECKS are disabled the code will contiue to compile and behave correctly. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-07userns: Disassociate user_struct from the user_namespace.Eric W. Biederman
Modify alloc_uid to take a kuid and make the user hash table global. Stop holding a reference to the user namespace in struct user_struct. This simplifies the code and makes the per user accounting not care about which user namespace a uid happens to appear in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-03-20block: remove ioc_*_changed()Tejun Heo
After the previous patch to cfq, there's no ioc_get_changed() user left. This patch yanks out ioc_{ioprio|cgroup|get}_changed() and all related stuff. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-02-07block: strip out locking optimization in put_io_context()Tejun Heo
put_io_context() performed a complex trylock dancing to avoid deferring ioc release to workqueue. It was also broken on UP because trylock was always assumed to succeed which resulted in unbalanced preemption count. While there are ways to fix the UP breakage, even the most pathological microbench (forced ioc allocation and tight fork/exit loop) fails to show any appreciable performance benefit of the optimization. Strip it out. If there turns out to be workloads which are affected by this change, simpler optimization from the discussion thread can be applied later. Signed-off-by: Tejun Heo <tj@kernel.org> LKML-Reference: <1328514611.21268.66.camel@sli10-conroe> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-12-14block, cfq: unlink cfq_io_context's immediatelyTejun Heo
cic is association between io_context and request_queue. A cic is linked from both ioc and q and should be destroyed when either one goes away. As ioc and q both have their own locks, locking becomes a bit complex - both orders work for removal from one but not from the other. Currently, cfq tries to circumvent this locking order issue with RCU. ioc->lock nests inside queue_lock but the radix tree and cic's are also protected by RCU allowing either side to walk their lists without grabbing lock. This rather unconventional use of RCU quickly devolves into extremely fragile convolution. e.g. The following is from cfqd going away too soon after ioc and q exits raced. general protection fault: 0000 [#1] PREEMPT SMP CPU 2 Modules linked in: [ 88.503444] Pid: 599, comm: hexdump Not tainted 3.1.0-rc10-work+ #158 Bochs Bochs RIP: 0010:[<ffffffff81397628>] [<ffffffff81397628>] cfq_exit_single_io_context+0x58/0xf0 ... Call Trace: [<ffffffff81395a4a>] call_for_each_cic+0x5a/0x90 [<ffffffff81395ab5>] cfq_exit_io_context+0x15/0x20 [<ffffffff81389130>] exit_io_context+0x100/0x140 [<ffffffff81098a29>] do_exit+0x579/0x850 [<ffffffff81098d5b>] do_group_exit+0x5b/0xd0 [<ffffffff81098de7>] sys_exit_group+0x17/0x20 [<ffffffff81b02f2b>] system_call_fastpath+0x16/0x1b The only real hot path here is cic lookup during request initialization and avoiding extra locking requires very confined use of RCU. This patch makes cic removal from both ioc and request_queue perform double-locking and unlink immediately. * From q side, the change is almost trivial as ioc->lock nests inside queue_lock. It just needs to grab each ioc->lock as it walks cic_list and unlink it. * From ioc side, it's a bit more difficult because of inversed lock order. ioc needs its lock to walk its cic_list but can't grab the matching queue_lock and needs to perform unlock-relock dancing. Unlinking is now wholly done from put_io_context() and fast path is optimized by using the queue_lock the caller already holds, which is by far the most common case. If the ioc accessed multiple devices, it tries with trylock. In unlikely cases of fast path failure, it falls back to full double-locking dance from workqueue. Double-locking isn't the prettiest thing in the world but it's *far* simpler and more understandable than RCU trick without adding any meaningful overhead. This still leaves a lot of now unnecessary RCU logics. Future patches will trim them. -v2: Vivek pointed out that cic->q was being dereferenced after cic->release() was called. Updated to use local variable @this_q instead. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-12-14block, cfq: move ioc ioprio/cgroup changed handling to cicTejun Heo
ioprio/cgroup change was handled by marking the changed state in ioc and, on the following access to the ioc, performing RCU-protected iteration through all cic's grabbing the matching queue_lock. This patch moves the changed state to each cic. When ioprio or cgroup changes, the respective bit is set on all cic's of the ioc and when each of those cic (not ioc) is accessed, change is applied for that specific ioc-queue pair. This also fixes the following two race conditions between setting and clearing of changed states. * Missing barrier between assign/load of ioprio and ioprio_changed allowed applying old ioprio. * Change requests could happen between application of change and clearing of changed variables. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-12-14block: make ioc get/put interface more conventional and fix race on alloctionTejun Heo
Ignoring copy_io() during fork, io_context can be allocated from two places - current_io_context() and set_task_ioprio(). The former is always called from local task while the latter can be called from different task. The synchornization between them are peculiar and dubious. * current_io_context() doesn't grab task_lock() and assumes that if it saw %NULL ->io_context, it would stay that way until allocation and assignment is complete. It has smp_wmb() between alloc/init and assignment. * set_task_ioprio() grabs task_lock() for assignment and does smp_read_barrier_depends() between "ioc = task->io_context" and "if (ioc)". Unfortunately, this doesn't achieve anything - the latter is not a dependent load of the former. ie, if ioc itself were being dereferenced "ioc->xxx", it would mean something (not sure what tho) but as the code currently stands, the dependent read barrier is noop. As only one of the the two test-assignment sequences is task_lock() protected, the task_lock() can't do much about race between the two. Nothing prevents current_io_context() and set_task_ioprio() allocating its own ioc for the same task and overwriting the other's. Also, set_task_ioprio() can race with exiting task and create a new ioc after exit_io_context() is finished. ioc get/put doesn't have any reason to be complex. The only hot path is accessing the existing ioc of %current, which is simple to achieve given that ->io_context is never destroyed as long as the task is alive. All other paths can happily go through task_lock() like all other task sub structures without impacting anything. This patch updates ioc get/put so that it becomes more conventional. * alloc_io_context() is replaced with get_task_io_context(). This is the only interface which can acquire access to ioc of another task. On return, the caller has an explicit reference to the object which should be put using put_io_context() afterwards. * The functionality of current_io_context() remains the same but when creating a new ioc, it shares the code path with get_task_io_context() and always goes through task_lock(). * get_io_context() now means incrementing ref on an ioc which the caller already has access to (be that an explicit refcnt or implicit %current one). * PF_EXITING inhibits creation of new io_context and once exit_io_context() is finished, it's guaranteed that both ioc acquisition functions return %NULL. * All users are updated. Most are trivial but smp_read_barrier_depends() removal from cfq_get_io_context() needs a bit of explanation. I suppose the original intention was to ensure ioc->ioprio is visible when set_task_ioprio() allocates new io_context and installs it; however, this wouldn't have worked because set_task_ioprio() doesn't have wmb between init and install. There are other problems with this which will be fixed in another patch. * While at it, use NUMA_NO_NODE instead of -1 for wildcard node specification. -v2: Vivek spotted contamination from debug patch. Removed. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-10-31fs: add export.h to files using EXPORT_SYMBOL/THIS_MODULE macrosPaul Gortmaker
These files were getting <linux/module.h> via an implicit include path, but we want to crush those out of existence since they cost time during compiles of processing thousands of lines of headers for no reason. Give them the lightweight header that just contains the EXPORT_SYMBOL infrastructure. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2010-11-15ioprio: grab rcu_read_lock in sys_ioprio_{set,get}()Greg Thelen
Using: - CONFIG_LOCKUP_DETECTOR=y - CONFIG_PREEMPT=y - CONFIG_LOCKDEP=y - CONFIG_PROVE_LOCKING=y - CONFIG_PROVE_RCU=y found a missing rcu lock during boot on a 512 MiB x86_64 ubuntu vm: =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- kernel/pid.c:419 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by ureadahead/1355: #0: (tasklist_lock){.+.+..}, at: [<ffffffff8115bc09>] sys_ioprio_set+0x7f/0x29e stack backtrace: Pid: 1355, comm: ureadahead Not tainted 2.6.37-dbg-DEV #1 Call Trace: [<ffffffff8109c10c>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffff81088cbf>] find_task_by_pid_ns+0x44/0x5d [<ffffffff81088cfa>] find_task_by_vpid+0x22/0x24 [<ffffffff8115bc3e>] sys_ioprio_set+0xb4/0x29e [<ffffffff8147cf21>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff8105c409>] sysenter_dispatch+0x7/0x2c [<ffffffff8147cee2>] ? trace_hardirqs_on_thunk+0x3a/0x3f The fix is to: a) grab rcu lock in sys_ioprio_{set,get}() and b) avoid grabbing tasklist_lock. Discussion in: http://marc.info/?l=linux-kernel&m=128951324702889 Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Modified by Jens to remove the now redundant inner rcu lock and unlock since they are now protected by the outer lock. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-10ioprio: rcu_read_lock/unlock protect find_task_by_vpid call (V2)Sergey Senozhatsky
Commit 4221a9918e38b7494cee341dda7b7b4bb8c04bde "Add RCU check for find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns= Assertion failed in sys_ioprio_get. The patch is fixing assertion failure in ioprio_set as well. kernel/pid.c:419 invoked rcu_dereference_check() without protection! stack backtrace: Pid: 4254, comm: iotop Not tainted Call Trace: [<ffffffff810656f2>] lockdep_rcu_dereference+0xaa/0xb2 [<ffffffff81053c67>] find_task_by_pid_ns+0x4f/0x68 [<ffffffff81053c9d>] find_task_by_vpid+0x1d/0x1f [<ffffffff811104e2>] sys_ioprio_get+0x50/0x2da [<ffffffff81002182>] system_call_fastpath+0x16/0x1b V2: rcu critical section expanded according to comment by Paul E. McKenney Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-10ioprio: fix RCU locking around task dereferenceDaniel J Blueman
With 2.6.37-rc1, I observe sys_ioprio_set not taking the RCU lock [1] across access to the task credentials. Inspecting the code in fs/ioprio.c, the tasklist_lock is held for read across the __task_cred call, which is presumably sufficient to prevent the task credentials becoming stale. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- kernel/pid.c:419 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 1 lock held by start-stop-daem/2246: #0: (tasklist_lock){.?.?..}, at: [<ffffffff811a2dfa>] sys_ioprio_set+0x8a/0x400 stack backtrace: Pid: 2246, comm: start-stop-daem Not tainted 2.6.37-rc1-330cd+ #2 Call Trace: [<ffffffff8109f5f4>] lockdep_rcu_dereference+0xa4/0xc0 [<ffffffff81085651>] find_task_by_pid_ns+0x81/0x90 [<ffffffff8108567d>] find_task_by_vpid+0x1d/0x20 [<ffffffff811a3160>] sys_ioprio_set+0x3f0/0x400 [<ffffffff816efa79>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff81003482>] system_call_fastpath+0x16/0x1b Take the RCU lock for read across acquiring the pointer to the task credentials and dereferencing it. Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> Fixed up by Jens to fix missing rcu_read_unlock() on mismatches. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
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>
2009-01-14[CVE-2009-0029] System call wrappers part 28Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-05ext4: Add mount option to set kjournald's I/O priorityTheodore Ts'o
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jens Axboe <jens.axboe@oracle.com>
2008-11-14CRED: Use RCU to access another task's creds and to release a task's own credsDavid Howells
Use RCU to access another task's creds and to release a task's own creds. This means that it will be possible for the credentials of a task to be replaced without another task (a) requiring a full lock to read them, and (b) seeing deallocated memory. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14CRED: Wrap current->cred and a few other accessorsDavid Howells
Wrap current->cred and a few other accessors to hide their actual implementation. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14CRED: Separate task security context from task_structDavid Howells
Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14CRED: Wrap task credential accesses in the filesystem subsystemDavid Howells
Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Morris <jmorris@namei.org>
2008-08-20fix setpriority(PRIO_PGRP) thread iterator breakageKen Chen
When user calls sys_setpriority(PRIO_PGRP ...) on a NPTL style multi-LWP process, only the task leader of the process is affected, all other sibling LWP threads didn't receive the setting. The problem was that the iterator used in sys_setpriority() only iteartes over one task for each process, ignoring all other sibling thread. Introduce a new macro do_each_pid_thread / while_each_pid_thread to walk each thread of a process. Convert 4 call sites in {set/get}priority and ioprio_{set/get}. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-28cfq-iosched: relax IOPRIO_CLASS_IDLE restrictionsJens Axboe
Currently you must be root to set idle io prio class on a process. This is due to the fact that the idle class is implemented as a true idle class, meaning that it will not make progress if someone else is requesting disk access. Unfortunately this means that it opens DOS opportunities by locking down file system resources, hence it is root only at the moment. This patch relaxes the idle class a little, by removing the truly idle part (which entals a grace period with associated timer). The modifications make the idle class as close to zero impact as can be done while still guarenteeing progress. This means we can relax the root only criteria as well. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28io context sharing: preliminary supportJens Axboe
Detach task state from ioc, instead keep track of how many processes are accessing the ioc. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28ioprio: move io priority from task_struct to io_contextJens Axboe
This is where it belongs and then it doesn't take up space for a process that doesn't do IO. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-07ioprio: allow sys_ioprio_set() value of 0 to reset ioprio settingJens Axboe
Normally io priorities follow the CPU nice, unless a specific scheduling class has been set. Once that is set, there's no way to reset the behaviour to 'none' so that it follows CPU nice again. Currently passing in 0 as the ioprio class/value will return -1/EINVAL, change that to allow resetting of a set scheduling class. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-19Uninline find_task_by_xxx set of functionsPavel Emelyanov
The find_task_by_something is a set of macros are used to find task by pid depending on what kind of pid is proposed - global or virtual one. All of them are wrappers above the most generic one - find_task_by_pid_type_ns() - and just substitute some args for it. It turned out, that dereferencing the current->nsproxy->pid_ns construction and pushing one more argument on the stack inline cause kernel text size to grow. This patch moves all this stuff out-of-line into kernel/pid.c. Together with the next patch it saves a bit less than 400 bytes from the .text section. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19pid namespaces: changes to show virtual ids to userPavel Emelyanov
This is the largest patch in the set. Make all (I hope) the places where the pid is shown to or get from user operate on the virtual pids. The idea is: - all in-kernel data structures must store either struct pid itself or the pid's global nr, obtained with pid_nr() call; - when seeking the task from kernel code with the stored id one should use find_task_by_pid() call that works with global pids; - when showing pid's numerical value to the user the virtual one should be used, but however when one shows task's pid outside this task's namespace the global one is to be used; - when getting the pid from userspace one need to consider this as the virtual one and use appropriate task/pid-searching functions. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: yet nuther build fix] [akpm@linux-foundation.org: remove unneeded casts] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] pid: replace do/while_each_task_pid with do/while_each_pid_taskEric W. Biederman
There isn't any real advantage to this change except that it allows the old functions to be removed. Which is easier on maintenance and puts the code in a more uniform style. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-10-12[PATCH] block layer: ioprio_best function fixVasily Tarasov
Currently ioprio_best function first checks wethere aioprio or bioprio equals IOPRIO_CLASS_NONE (ioprio_valid() macros does that) and if it is so it returns bioprio/aioprio appropriately. Thus the next four lines, that set aclass/bclass to IOPRIO_CLASS_BE, if aclass/bclass == IOPRIO_CLASS_NONE, are never executed. The second problem: if aioprio from class IOPRIO_CLASS_NONE and bioprio from class IOPRIO_CLASS_IDLE are passed to ioprio_best function, it will return IOPRIO_CLASS_IDLE. It means that during __make_request we can merge two requests and set the priority of merged request to IDLE, while one of the initial requests originates from a process with NONE (default) priority. So we can get a situation when a process with default ioprio will experience IO starvation, while there is no process from real-time class in the system. Just removing ioprio_valid check should correct situation. Signed-off-by: Vasily Tarasov <vtaras@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-09-30[PATCH] Update axboe@suse.de email addressJens Axboe
As people often look for the copyright in files to see who to mail, update the link to a neutral one. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30[PATCH] Don't need to disable interrupts for tasklist_lockOleg Nesterov
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30[PATCH] cfq-iosched: kill cfq_exit_lockJens Axboe
cfq_exit_lock is protecting two things now: - The per-ioc rbtree of cfq_io_contexts - The per-cfqd linked list of cfq_io_contexts The per-cfqd linked list can be protected by the queue lock, as it is (by definition) per cfqd as the queue lock is. The per-ioc rbtree is mainly used and updated by the process itself only. The only outside use is the io priority changing. If we move the priority changing to not browsing the rbtree, we can remove any locking from the rbtree updates and lookup completely. Let the sys_ioprio syscall just mark processes as having the iopriority changed and lazily update the private cfq io contexts the next time io is queued, and we can remove this locking as well. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-08-21[PATCH] uninline ioprio_best()Oleg Nesterov
Saves 376 bytes (5 callers) for me. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-08-21[PATCH] Fix current_io_context() vs set_task_ioprio() raceOleg Nesterov
I know nothing about io scheduler, but I suspect set_task_ioprio() is not safe. current_io_context() initializes "struct io_context", then sets ->io_context. set_task_ioprio() running on another cpu may see the changes out of order, so ->set_ioprio(ioc) may use io_context which was not initialized properly. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-08-21[PATCH] sys_ioprio_set: minor do_each_thread+break fixOleg Nesterov
From include/linux/sched.h: * Careful: do_each_thread/while_each_thread is a double loop so * 'break' will not work as expected - use goto instead. */ Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-30[PATCH] SELinux: Add security hook definition for getioprio and insert hooksDavid Quigley
Add a new security hook definition for the sys_ioprio_get operation. At present, the SELinux hook function implementation for this hook is identical to the getscheduler implementation but a separate hook is introduced to allow this check to be specialized in the future if necessary. This patch also creates a helper function get_task_ioprio which handles the access check in addition to retrieving the ioprio value for the task. Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org> Cc: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] lsm: add task_setioprio hookJames Morris
Implement an LSM hook for setting a task's IO priority, similar to the hook for setting a tasks's nice value. A previous version of this LSM hook was included in an older version of multiadm by Jan Engelhardt, although I don't recall it being submitted upstream. Also included is the corresponding SELinux hook, which re-uses the setsched permission in the proccess class. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11[PATCH] capable/capability.h (fs/)Randy Dunlap
fs: Use <linux/capability.h> where capable() is used. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Tim Schmielau <tim@physik3.uni-rostock.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-08fs/ioprio.c should #include <linux/syscalls.h>Adrian Bunk
Every file should include the headers containing the prototypes for it's global functions. Signed-off-by: Adrian Bunk <bunk@stusta.de>
2005-08-20Don't allow normal users to set idle IO priorityLinus Torvalds
It has all the normal priority inversion problems. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] move ioprio syscalls into syscalls.hAnton Blanchard
- Make ioprio syscalls return long, like set/getpriority syscalls. - Move function prototypes into syscalls.h so we can pick them up in the 32/64bit compat code. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27[PATCH] Update cfq io scheduler to time sliced designJens Axboe
This updates the CFQ io scheduler to the new time sliced design (cfq v3). It provides full process fairness, while giving excellent aggregate system throughput even for many competing processes. It supports io priorities, either inherited from the cpu nice value or set directly with the ioprio_get/set syscalls. The latter closely mimic set/getpriority. This import is based on my latest from -mm. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>