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* /proc/sysvipc/shm: fix 32-bit truncation of segment sizesPaul Menage2008-06-131-8/+8
| | | | | | | | | | | | | | | | | | | | | sysvipc_shm_proc_show() picks between format strings (based on the expected maximum length of a SHM segment) in a way that prevents gcc from performing format checks on the seq_printf() parameters. This hid two format errors - shp->shm_segsz and shp->shm_nattach are both unsigned long, but were being printed as unsigned int and signed int respectively. This leads to 32-bit truncation of SHM segment sizes reported in /proc/sysvipc/shm. (And for nattach, but that's less of a problem for most users). This patch makes the format string directly visible to gcc's format specifier checker, and fixes the two broken format specifiers. Signed-off-by: Paul Menage <menage@google.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* shm: Remove silly double assignmentNeil Horman2008-06-101-2/+0
| | | | | | | | Found a silly double assignment of err is do_shmat. Silly, but good to clean up the useless code. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: only output msgmni value at boot timeNadia Derbey2008-06-061-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | When posting: [PATCH 1/8] Scaling msgmni to the amount of lowmem (see http://lkml.org/lkml/2008/2/11/171), I have added a KERN_INFO message that is output each time msgmni is recomputed. In http://lkml.org/lkml/2008/4/29/575 Tony Luck complained that this message references an ipc namespace address that is useless. I first thought of using an audit_log instead of a printk, as suggested by Serge Hallyn. But unfortunately, we do not have any other information than the namespace address to provide here too. So I chose to move the message and output it only at boot time, removing the reference to the namespace. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Pierre Peiffer <peifferp@gmail.com> Cc: Manfred Spraul <manfred@colorfullife.com> Acked-by: Tony Luck <tony.luck@intel.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tiny mq_open optimizationUlrich Drepper2008-05-031-2/+1
| | | | | | | | | | | A very small cleanup for mq_open. We do not have to call set_close_on_exit if we create the file descriptor right away with the flag set. We have a function for this now. The resulting code is smaller and a tiny bit faster. Signed-off-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysvipc: use non-racy method for proc entries creationDenis V. Lunev2008-04-291-7/+6
| | | | | | | | | | | | | Use proc_create_data() to make sure that ->proc_fops and ->data be setup before gluing PDE to main tree. Signed-off-by: Denis V. Lunev <den@openvz.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: sysvsem: implement sys_unshare(CLONE_SYSVSEM)Manfred Spraul2008-04-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing undo lists. Fix, part 1: add support for sys_unshare(CLONE_SYSVSEM) The original reason to not support it was the potential (inevitable?) confusion due to the fact that sys_unshare(CLONE_SYSVSEM) has the inverse meaning of clone(CLONE_SYSVSEM). Our two most reasonable options then appear to be (1) fully support CLONE_SYSVSEM, or (2) continue to refuse explicit CLONE_SYSVSEM, but always do it anyway on unshare(CLONE_SYSVSEM). This patch does (1). Changelog: Apr 16: SEH: switch to Manfred's alternative patch which removes the unshare_semundo() function which always refused CLONE_SYSVSEM. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: add definitions of USHORT_MAX and othersZhang, Yanmin2008-04-293-9/+8
| | | | | | | | | | | | | Add definitions of USHORT_MAX and others into kernel. ipc uses it and slub implementation might also use it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com> Reviewed-by: Christoph Lameter <clameter@sgi.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: "Pierre Peiffer" <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC: consolidate all xxxctl_down() functionsPierre Peiffer2008-04-295-119/+66
| | | | | | | | | | | | | | | | | | | semctl_down(), msgctl_down() and shmctl_down() are used to handle the same set of commands for each kind of IPC. They all start to do the same job (they retrieve the ipc and do some permission checks) before handling the commands on their own. This patch proposes to consolidate this by moving these same pieces of code into one common function called ipcctl_pre_down(). It simplifies a little these xxxctl_down() functions and increases a little the maintainability. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC: introduce ipc_update_perm()Pierre Peiffer2008-04-295-12/+17
| | | | | | | | | | | | The IPC_SET command performs the same permission setting for all IPCs. This patch introduces a common ipc_update_perm() function to update these permissions and makes use of it for all IPCs. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC: get rid of the use *_setbuf structure.Pierre Peiffer2008-04-293-86/+46
| | | | | | | | | | | | | | | | | | All IPCs make use of an intermetiate *_setbuf structure to handle the IPC_SET command. This is not really needed and, moreover, it complicates a little bit the code. This patch gets rid of the use of it and uses directly the semid64_ds/ msgid64_ds/shmid64_ds structure. In addition of removing one struture declaration, it also simplifies and improves a little bit the common 64-bits path. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC/semaphores: remove one unused parameter from semctl_down()Pierre Peiffer2008-04-291-3/+3
| | | | | | | | | | | semctl_down() takes one unused parameter: semnum. This patch proposes to get rid of it. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC/semaphores: move the rwmutex handling inside semctl_downPierre Peiffer2008-04-291-11/+13
| | | | | | | | | | | | | | | | | semctl_down is called with the rwmutex (the one which protects the list of ipcs) taken in write mode. This patch moves this rwmutex taken in write-mode inside semctl_down. This has the advantages of reducing a little bit the window during which this rwmutex is taken, clarifying sys_semctl, and finally of having a coherent behaviour with [shm|msg]ctl_down Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC/message queues: introduce msgctl_downPierre Peiffer2008-04-291-73/+89
| | | | | | | | | | | | | | | | | | Currently, sys_msgctl is not easy to read. This patch tries to improve that by introducing the msgctl_down function to handle all commands requiring the rwmutex to be taken in write mode (ie IPC_SET and IPC_RMID for now). It is the equivalent function of semctl_down for message queues. This greatly changes the readability of sys_msgctl and also harmonizes the way these commands are handled among all IPCs. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC/shared memory: introduce shmctl_downPierre Peiffer2008-04-291-88/+72
| | | | | | | | | | | | | | | | | | Currently, the way the different commands are handled in sys_shmctl introduces some duplicated code. This patch introduces the shmctl_down function to handle all the commands requiring the rwmutex to be taken in write mode (ie IPC_SET and IPC_RMID for now). It is the equivalent function of semctl_down for shared memory. This removes some duplicated code for handling these both commands and harmonizes the way they are handled among all IPCs. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC/semaphores: code factorisationPierre Peiffer2008-04-291-30/+31
| | | | | | | | | | | Trivial patch which adds some small locking functions and makes use of them to factorize some part of the code and to make it cleaner. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: re-enable msgmni automatic recomputing msgmni if set to negativeNadia Derbey2008-04-292-10/+44
| | | | | | | | | | | | | | | | | | The enhancement as asked for by Yasunori: if msgmni is set to a negative value, register it back into the ipcns notifier chain. A new interface has been added to the notification mechanism: notifier_chain_cond_register() registers a notifier block only if not already registered. With that new interface we avoid taking care of the states changes in procfs. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: do not recompute msgmni anymore if explicitly set by userNadia Derbey2008-04-291-2/+41
| | | | | | | | | | | | | | | | Make msgmni not recomputed anymore upon ipc namespace creation / removal or memory add/remove, as soon as it has been set from userland. As soon as msgmni is explicitly set via procfs or sysctl(), the associated callback routine is unregistered from the ipc namespace notifier chain. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: recompute msgmni on ipc namespace creation/removalNadia Derbey2008-04-293-2/+15
| | | | | | | | | | | | | | | | | | | | | Introduce a notification mechanism that aims at recomputing msgmni each time an ipc namespace is created or removed. The ipc namespace notifier chain already defined for memory hotplug management is used for that purpose too. Each time a new ipc namespace is allocated or an existing ipc namespace is removed, the ipcns notifier chain is notified. The callback routine for each registered ipc namespace is then activated in order to recompute msgmni for that namespace. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: invoke the ipcns notifier chain as a work itemNadia Derbey2008-04-291-1/+14
| | | | | | | | | | | | | | | Make the memory hotplug chain's mutex held for a shorter time: when memory is offlined or onlined a work item is added to the global workqueue. When the work item is run, it notifies the ipcns notifier chain with the IPCNS_MEMCHANGED event. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: recompute msgmni on memory add / removeNadia Derbey2008-04-296-2/+120
| | | | | | | | | | | | | | | | | | | | | | | | | Introduce the registration of a callback routine that recomputes msg_ctlmni upon memory add / remove. A single notifier block is registered in the hotplug memory chain for all the ipc namespaces. Since the ipc namespaces are not linked together, they have their own notification chain: one notifier_block is defined per ipc namespace. Each time an ipc namespace is created (removed) it registers (unregisters) its notifier block in (from) the ipcns chain. The callback routine registered in the memory chain invokes the ipcns notifier chain with the IPCNS_LOWMEM event. Each callback routine registered in the ipcns namespace, in turn, recomputes msgmni for the owning namespace. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: scale msgmni to the number of ipc namespacesNadia Derbey2008-04-293-3/+13
| | | | | | | | | | | | | | Since all the namespaces see the same amount of memory (the total one) this patch introduces a new variable that counts the ipc namespaces and divides msg_ctlmni by this counter. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: scale msgmni to the amount of lowmemNadia Derbey2008-04-291-1/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On large systems we'd like to allow a larger number of message queues. In some cases up to 32K. However simply setting MSGMNI to a larger value may cause problems for smaller systems. The first patch of this series introduces a default maximum number of message queue ids that scales with the amount of lowmem. Since msgmni is per namespace and there is no amount of memory dedicated to each namespace so far, the second patch of this series scales msgmni to the number of ipc namespaces too. Since msgmni depends on the amount of memory, it becomes necessary to recompute it upon memory add/remove. In the 4th patch, memory hotplug management is added: a notifier block is registered into the memory hotplug notifier chain for the ipc subsystem. Since the ipc namespaces are not linked together, they have their own notification chain: one notifier_block is defined per ipc namespace. Each time an ipc namespace is created (removed) it registers (unregisters) its notifier block in (from) the ipcns chain. The callback routine registered in the memory chain invokes the ipcns notifier chain with the IPCNS_MEMCHANGE event. Each callback routine registered in the ipcns namespace, in turn, recomputes msgmni for the owning namespace. The 5th patch makes it possible to keep the memory hotplug notifier chain's lock for a lesser amount of time: instead of directly notifying the ipcns notifier chain upon memory add/remove, a work item is added to the global workqueue. When activated, this work item is the one who notifies the ipcns notifier chain. Since msgmni depends on the number of ipc namespaces, it becomes necessary to recompute it upon ipc namespace creation / removal. The 6th patch uses the ipc namespace notifier chain for that purpose: that chain is notified each time an ipc namespace is created or removed. This makes it possible to recompute msgmni for all the namespaces each time one of them is created or removed. When msgmni is explicitely set from userspace, we should avoid recomputing it upon memory add/remove or ipcns creation/removal. This is what the 7th patch does: it simply unregisters the ipcns callback routine as soon as msgmni has been changed from procfs or sysctl(). Even if msgmni is set by hand, it should be possible to make it back automatically recomputed upon memory add/remove or ipcns creation/removal. This what is achieved in patch 8: if set to a negative value, msgmni is added back to the ipcns notifier chain, making it automatically recomputed again. This patch: Compute msg_ctlmni to make it scale with the amount of lowmem. msg_ctlmni is now set to make the message queues occupy 1/32 of the available lowmem. Some cleaning has also been done for the MSGPOOL constant: the msgctl man page says it's not used, but it also defines it as a size in bytes (the code expresses it in Kbytes). Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC: use ipc_buildid() directly from ipc_addid()Pierre Peiffer2008-04-294-13/+2
| | | | | | | | | | | | | | | By continuing to consolidate a little the IPC code, each id can be built directly in ipc_addid() instead of having it built from each callers of ipc_addid() And I also remove shm_addid() in order to have, as much as possible, the same code for shm/sem/msg. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mempolicy: rework mempolicy Reference Counting [yet again]Lee Schermerhorn2008-04-281-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After further discussion with Christoph Lameter, it has become clear that my earlier attempts to clean up the mempolicy reference counting were a bit of overkill in some areas, resulting in superflous ref/unref in what are usually fast paths. In other areas, further inspection reveals that I botched the unref for interleave policies. A separate patch, suitable for upstream/stable trees, fixes up the known errors in the previous attempt to fix reference counting. This patch reworks the memory policy referencing counting and, one hopes, simplifies the code. Maybe I'll get it right this time. See the update to the numa_memory_policy.txt document for a discussion of memory policy reference counting that motivates this patch. Summary: Lookup of mempolicy, based on (vma, address) need only add a reference for shared policy, and we need only unref the policy when finished for shared policies. So, this patch backs out all of the unneeded extra reference counting added by my previous attempt. It then unrefs only shared policies when we're finished with them, using the mpol_cond_put() [conditional put] helper function introduced by this patch. Note that shmem_swapin() calls read_swap_cache_async() with a dummy vma containing just the policy. read_swap_cache_async() can call alloc_page_vma() multiple times, so we can't let alloc_page_vma() unref the shared policy in this case. To avoid this, we make a copy of any non-null shared policy and remove the MPOL_F_SHARED flag from the copy. This copy occurs before reading a page [or multiple pages] from swap, so the overhead should not be an issue here. I introduced a new static inline function "mpol_cond_copy()" to copy the shared policy to an on-stack policy and remove the flags that would require a conditional free. The current implementation of mpol_cond_copy() assumes that the struct mempolicy contains no pointers to dynamically allocated structures that must be duplicated or reference counted during copy. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mempolicy: fixup Fallback for Default Shmem PolicyLee Schermerhorn2008-04-281-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | get_vma_policy() is not handling fallback to task policy correctly when the get_policy() vm_op returns NULL. The NULL overwrites the 'pol' variable that was holding the fallback task mempolicy. So, it was falling back directly to system default policy. Fix get_vma_policy() to use only non-NULL policy returned from the vma get_policy op. shm_get_policy() was falling back to current task's mempolicy if the "backing file system" [tmpfs vs hugetlbfs] does not support the get_policy vm_op and the vma policy is null. This is incorrect for show_numa_maps() which is likely querying the numa_maps of some task other than current. Remove this fallback. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] r/o bind mounts: elevate write count for open()sDave Hansen2008-04-191-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | This is the first really tricky patch in the series. It elevates the writer count on a mount each time a non-special file is opened for write. We used to do this in may_open(), but Miklos pointed out that __dentry_open() is used as well to create filps. This will cover even those cases, while a call in may_open() would not have. There is also an elevated count around the vfs_create() call in open_namei(). See the comments for more details, but we need this to fix a 'create, remount, fail r/w open()' race. Some filesystems forego the use of normal vfs calls to create struct files. Make sure that these users elevate the mnt writer count because they will get __fput(), and we need to make sure they're balanced. Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] r/o bind mounts: elevate write count for rmdir and unlink.Dave Hansen2008-04-191-1/+4
| | | | | | | | | | | | | Elevate the write count during the vfs_rmdir() and vfs_unlink(). [AV: merged rmdir and unlink parts, added missing pieces in nfsd] Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mempolicy: fix reference counting bugsLee Schermerhorn2008-03-111-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Address 3 known bugs in the current memory policy reference counting method. I have a series of patches to rework the reference counting to reduce overhead in the allocation path. However, that series will require testing in -mm once I repost it. 1) alloc_page_vma() does not release the extra reference taken for vma/shared mempolicy when the mode == MPOL_INTERLEAVE. This can result in leaking mempolicy structures. This is probably occurring, but not being noticed. Fix: add the conditional release of the reference. 2) hugezonelist unconditionally releases a reference on the mempolicy when mode == MPOL_INTERLEAVE. This can result in decrementing the reference count for system default policy [should have no ill effect] or premature freeing of task policy. If this occurred, the next allocation using task mempolicy would use the freed structure and probably BUG out. Fix: add the necessary check to the release. 3) The current reference counting method assumes that vma 'get_policy()' methods automatically add an extra reference a non-NULL returned mempolicy. This is true for shmem_get_policy() used by tmpfs mappings, including regular page shm segments. However, SHM_HUGETLB shm's, backed by hugetlbfs, just use the vma policy without the extra reference. This results in freeing of the vma policy on the first allocation, with reuse of the freed mempolicy structure on subsequent allocations. Fix: Rather than add another condition to the conditional reference release, which occur in the allocation path, just add a reference when returning the vma policy in shm_get_policy() to match the assumptions. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Greg KH <greg@kroah.com> Cc: Andi Kleen <ak@suse.de> Cc: Christoph Lameter <clameter@sgi.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: David Rientjes <rientjes@google.com> Cc: <eric.whitney@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Pidns: fix badly converted mqueues pid handlingPavel Emelyanov2008-02-081-1/+1
| | | | | | | | | | | | | | | | | When sending the pid namespaces patches I wrongly converted the tsk->tgid into task_pid_vnr(tsk) in mqueue-s (the git id of this patch is b488893a390edfe027bae7a46e9af8083e740668). The proper behavior is to get the task_tgid_vnr(tsk). This seem to be the only mistake of that kind. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Pidns: make full use of xxx_vnr() callsPavel Emelyanov2008-02-081-2/+1
| | | | | | | | | | | | | | | | | Some time ago the xxx_vnr() calls (e.g. pid_vnr or find_task_by_vpid) were _all_ converted to operate on the current pid namespace. After this each call like xxx_nr_ns(foo, current->nsproxy->pid_ns) is nothing but a xxx_vnr(foo) one. Switch all the xxx_nr_ns() callers to use the xxx_vnr() calls where appropriate. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Reviewed-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC: consolidate sem_exit_ns(), msg_exit_ns() and shm_exit_ns()Pierre Peiffer2008-02-084-66/+46
| | | | | | | | | | | | | | | | | | | | sem_exit_ns(), msg_exit_ns() and shm_exit_ns() are all called when an ipc_namespace is released to free all ipcs of each type. But in fact, they do the same thing: they loop around all ipcs to free them individually by calling a specific routine. This patch proposes to consolidate this by introducing a common function, free_ipcs(), that do the job. The specific routine to call on each individual ipcs is passed as parameter. For this, these ipc-specific 'free' routines are reworked to take a generic 'struct ipc_perm' as parameter. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC: make struct ipc_ids static in ipc_namespacePierre Peiffer2008-02-086-102/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | Each ipc_namespace contains a table of 3 pointers to struct ipc_ids (3 for msg, sem and shm, structure used to store all ipcs) These 'struct ipc_ids' are dynamically allocated for each icp_namespace as the ipc_namespace itself (for the init namespace, they are initialized with pointers to static variables instead) It is so for historical reason: in fact, before the use of idr to store the ipcs, the ipcs were stored in tables of variable length, depending of the maximum number of ipc allowed. Now, these 'struct ipc_ids' have a fixed size. As they are allocated in any cases for each new ipc_namespace, there is no gain of memory in having them allocated separately of the struct ipc_namespace. This patch proposes to make this table static in the struct ipc_namespace. Thus, we can allocate all in once and get rid of all the code needed to allocate and free these ipc_ids separately. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC/semaphores: consolidate SEM_STAT and IPC_STAT commandsPierre Peiffer2008-02-081-22/+16
| | | | | | | | | | | | | | | | These commands (SEM_STAT and IPC_STAT) are rather doing the same things (only the meaning of the id given as input and the return value differ). However, for the semaphores, they are handled in two different places (two different functions). This patch consolidates this for clarification by handling these both commands in the same place in semctl_nolock(). It also removes one unused parameter for this function. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: uninline some code from util.hPavel Emelyanov2008-02-082-58/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ipc_lock_check_down(), ipc_lock_check() and ipcget() seem too large to be inline. Besides, they give no optimization being inline as they perform calls inside in any case. Moving them into ipc/util.c saves 500 bytes of vmlinux and shortens IPC internal API. $ ./scripts/bloat-o-meter vmlinux-orig vmlinux add/remove: 3/2 grow/shrink: 0/10 up/down: 490/-989 (-499) function old new delta ipcget - 392 +392 ipc_lock_check_down - 49 +49 ipc_lock_check - 49 +49 sys_semget 119 105 -14 sys_shmget 108 86 -22 sys_msgget 100 78 -22 do_msgsnd 665 631 -34 do_msgrcv 680 644 -36 do_shmat 771 733 -38 sys_msgctl 1302 1229 -73 ipcget_new 80 - -80 sys_semtimedop 1534 1452 -82 sys_semctl 2034 1922 -112 sys_shmctl 1919 1765 -154 ipcget_public 322 - -322 The ipcget() growth is the result of gcc inlining of currently static ipcget_new/_public. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* namespaces: move the IPC namespace under IPC_NS optionPavel Emelyanov2008-02-088-60/+87
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the IPC namespace management code is spread over the ipc/*.c files. I moved this code into ipc/namespace.c file which is compiled out when needed. The linux/ipc_namespace.h file is used to store the prototypes of the functions in namespace.c and the stubs for NAMESPACES=n case. This is done so, because the stub for copy_ipc_namespace requires the knowledge of the CLONE_NEWIPC flag, which is in sched.h. But the linux/ipc.h file itself in included into many many .c files via the sys.h->sem.h sequence so adding the sched.h into it will make all these .c depend on sched.h which is not that good. On the other hand the knowledge about the namespaces stuff is required in 4 .c files only. Besides, this patch compiles out some auxiliary functions from ipc/sem.c, msg.c and shm.c files. It turned out that moving these functions into namespaces.c is not that easy because they use many other calls and macros from the original file. Moving them would make this patch complicated. On the other hand all these functions can be consolidated, so I will send a separate patch doing this a bit later. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* make ipc/util.c:sysvipc_find_ipc() staticAdrian Bunk2008-02-061-2/+2
| | | | | | | | | sysvipc_find_ipc() can become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC: fix error check in all new xxx_lock() and xxx_exit_ns() functionsPierre Peiffer2008-02-063-9/+45
| | | | | | | | | | | | | | | | | | | | | | | | | In the new implementation of the [sem|shm|msg]_lock[_check]() routines, we use the return value of ipc_lock() in container_of() without any check. But ipc_lock may return a errcode. The use of this errcode in container_of() may alter this errcode, and we don't want this. And in xxx_exit_ns, the pointer return by idr_find is of type 'struct kern_ipc_per'... Today, the code will work as is because the member used in these container_of() is the first member of its container (offset == 0), the errcode isn't changed then. But in the general case, we can't count on this assumption and this may lead later to a real bug if we don't correct this. Again, the proposed solution is simple and correct. But, as pointed by Nadia, with this solution, the same check will be done several times (in all sub-callers...), what is not very funny/optimal... Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: lost unlock and fput in mqueue.c on error pathPavel Emelyanov2007-11-291-2/+4
| | | | | | | | | | | | | | The error path in sys_mq_getsetattr() after the call to audit_mq_getsetattr() is wrong - the info->lock is not unlocked and the struct file *filp is not put. Fix them both. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [NETLINK]: Fix unicast timeoutsPatrick McHardy2007-11-071-2/+4
| | | | | | | | | | | | | Commit ed6dcf4a in the history.git tree broke netlink_unicast timeouts by moving the schedule_timeout() call to a new function that doesn't propagate the remaining timeout back to the caller. This means on each retry we start with the full timeout again. ipc/mqueue.c seems to actually want to wait indefinitely so this behaviour is retained. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* [PATCH] pass dentry to audit_inode()/audit_inode_child()Al Viro2007-10-211-4/+4
| | | | | | makes caller simpler *and* allows to scan ancestors Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* IPC: fix error case when idr-cache is empty in ipcget()Pierre Peiffer2007-10-194-11/+18
| | | | | | | | | | | | | | | With the use of idr to store the ipc, the case where the idr cache is empty, when idr_get_new is called (this may happen even if we call idr_pre_get() before), is not well handled: it lets semget()/shmget()/msgget() return ENOSPC when this cache is empty, what 1. does not reflect the facts and 2. does not conform to the man(s). This patch fixes this by retrying the whole process of allocation in this case. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtualization of sysv msg queues is incompleteKirill Korotaev2007-10-191-11/+10
| | | | | | | | | | | | | | | Virtualization of sysv msg queues is incomplete: msg_hdrs and msg_bytes variables visible from userspace are global. Let's make them per-namespace. Signed-off-by: Alexey Kuznetsov <alexey@openvz.org> Signed-off-by: Kirill Korotaev <dev@openvz.org> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Serge Hallyn <serue@us.ibm.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* IPC: cleanup some code and wrong comments about semundo list managmentPierre Peiffer2007-10-191-40/+6
| | | | | | | | | | | | | | | | | | | | Some comments about sem_undo_list seem wrong. About the comment above unlock_semundo: "... If task2 now exits before task1 releases the lock (by calling unlock_semundo()), then task1 will never call spin_unlock(). ..." This is just wrong, I see no reason for which task1 will not call spin_unlock... The rest of this comment is also wrong... Unless I miss something (of course). Finally, (un)lock_semundo functions are useless, so remove them for simplification. (this avoids an useless if statement) Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: remove unneeded parametersNadia Derbey2007-10-194-17/+12
| | | | | | | | | Remvoe the unneeded parameters from ipc_checkid() and ipc_buildid() interfaces. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix idr_find() lockingNadia Derbey2007-10-195-70/+198
| | | | | | | | | | | | | | | | | | This is a patch that fixes the way idr_find() used to be called in ipc_lock(): in all the paths that don't imply an update of the ipcs idr, it was called without the idr tree being locked. The changes are: . in ipc_ids, the mutex has been changed into a reader/writer semaphore. . ipc_lock() now takes the mutex as a reader during the idr_find(). . a new routine ipc_lock_down() has been defined: it doesn't take the mutex, assuming that it is being held by the caller. This is the routine that is now called in all the update paths. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Acked-by: Jarek Poplawski <jarkao2@o2.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: fix wrong commentsNadia Derbey2007-10-195-45/+118
| | | | | | | | | This patch fixes the wrong / obsolete comments in the ipc code. Also adds a missing lock around ipc_get_maxid() in shm_get_stat(). Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: inline ipc_buildid()Nadia Derbey2007-10-192-6/+5
| | | | | | | | | This is a trivial patch that changes the ipc_buildid() routine into a static inline. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: introduce the ipcid_to_idx macroNadia Derbey2007-10-192-2/+4
| | | | | | | | | This is a trivial patch that changes all the (id % SEQ_MULTIPLIER) into a call to the ipcid_to_idx(id) macro. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Storing ipcs into IDRsNadia Derbey2007-10-194-18/+46
| | | | | | | | | | | | | | This patch converts casts of struct kern_ipc_perm to . struct msg_queue . struct sem_array . struct shmid_kernel into the equivalent container_of() macro. It improves code maintenance because the code need not change if kern_ipc_perm is no longer at the beginning of the containing struct. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: integrate ipc_checkid() into ipc_lock()Nadia Derbey2007-10-195-136/+152
| | | | | | | | | | | | This patch introduces a new ipc_lock_check() routine interface: . each time ipc_checkid() is called, this is done after calling ipc_lock(). ipc_checkid() is now called from inside ipc_lock_check(). [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix RCU locking] Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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