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* signal/timer/event: KAIO eventfd support exampleDavide Libenzi2007-05-111-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is an example about how to add eventfd support to the current KAIO code, in order to enable KAIO to post readiness events to a pollable fd (hence compatible with POSIX select/poll). The KAIO code simply signals the eventfd fd when events are ready, and this triggers a POLLIN in the fd. This patch uses a reserved for future use member of the struct iocb to pass an eventfd file descriptor, that KAIO will use to post events every time a request completes. At that point, an aio_getevents() will return the completed result to a struct io_event. I made a quick test program to verify the patch, and it runs fine here: http://www.xmailserver.org/eventfd-aio-test.c The test program uses poll(2), but it'd, of course, work with select and epoll too. This can allow to schedule both block I/O and other poll-able devices requests, and wait for results using select/poll/epoll. In a typical scenario, an application would submit KAIO request using aio_submit(), and will also use epoll_ctl() on the whole other class of devices (that with the addition of signals, timers and user events, now it's pretty much complete), and then would: epoll_wait(...); for_each_event { if (curr_event_is_kaiofd) { aio_getevents(); dispatch_aio_events(); } else { dispatch_epoll_event(); } } Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* unify flush_work/flush_work_keventd and rename it to cancel_work_syncOleg Nesterov2007-05-091-2/+2
| | | | | | | | | | | | | | | | | | | | flush_work(wq, work) doesn't need the first parameter, we can use cwq->wq (this was possible from the very beginnig, I missed this). So we can unify flush_work_keventd and flush_work. Also, rename flush_work() to cancel_work_sync() and fix all callers. Perhaps this is not the best name, but "flush_work" is really bad. (akpm: this is why the earlier patches bypassed maintainers) Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jeff Garzik <jeff@garzik.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Cc: Auke Kok <auke-jan.h.kok@intel.com>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: use flush_work()Andrew Morton2007-05-091-4/+3
| | | | | | | | | | | | Migrate AIO over to use flush_work(). Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: Benjamin LaHaise <bcrl@kvack.org> 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>
* KMEM_CACHE(): simplify slab cache creationChristoph Lameter2007-05-071-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch provides a new macro KMEM_CACHE(<struct>, <flags>) to simplify slab creation. KMEM_CACHE creates a slab with the name of the struct, with the size of the struct and with the alignment of the struct. Additional slab flags may be specified if necessary. Example struct test_slab { int a,b,c; struct list_head; } __cacheline_aligned_in_smp; test_slab_cache = KMEM_CACHE(test_slab, SLAB_PANIC) will create a new slab named "test_slab" of the size sizeof(struct test_slab) and aligned to the alignment of test slab. If it fails then we panic. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] aio: remove bare user-triggerable error printkZach Brown2007-03-271-1/+0
| | | | | | | | | | | | The user can generate console output if they cause do_mmap() to fail during sys_io_setup(). This was seen in a regression test that does exactly that by spinning calling mmap() until it gets -ENOMEM before calling io_setup(). We don't need this printk at all, just remove it. Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Transform kmem_cache_alloc()+memset(0) -> kmem_cache_zalloc().Robert P. J. Day2007-02-111-2/+1
| | | | | | | | | | | | | | | | | | | | | | Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the corresponding "kmem_cache_zalloc()" call. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@muc.de> Cc: Roland McGrath <roland@redhat.com> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Greg KH <greg@kroah.com> Acked-by: Joel Becker <Joel.Becker@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Jan Kara <jack@ucw.cz> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Remove final references to deprecated "MAP_ANON" page protection flagRobert P. J. Day2007-02-111-1/+1
| | | | | | | | | Remove the last vestiges of the long-deprecated "MAP_ANON" page protection flag: use "MAP_ANONYMOUS" instead. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] aio: fix buggy put_ioctx call in aio_complete - v2Ken Chen2007-02-031-11/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An AIO bug was reported that sleeping function is being called in softirq context: BUG: warning at kernel/mutex.c:132/__mutex_lock_common() Call Trace: [<a000000100577b00>] __mutex_lock_slowpath+0x640/0x6c0 [<a000000100577ba0>] mutex_lock+0x20/0x40 [<a0000001000a25b0>] flush_workqueue+0xb0/0x1a0 [<a00000010018c0c0>] __put_ioctx+0xc0/0x240 [<a00000010018d470>] aio_complete+0x2f0/0x420 [<a00000010019cc80>] finished_one_bio+0x200/0x2a0 [<a00000010019d1c0>] dio_bio_complete+0x1c0/0x200 [<a00000010019d260>] dio_bio_end_aio+0x60/0x80 [<a00000010014acd0>] bio_endio+0x110/0x1c0 [<a0000001002770e0>] __end_that_request_first+0x180/0xba0 [<a000000100277b90>] end_that_request_chunk+0x30/0x60 [<a0000002073c0c70>] scsi_end_request+0x50/0x300 [scsi_mod] [<a0000002073c1240>] scsi_io_completion+0x200/0x8a0 [scsi_mod] [<a0000002074729b0>] sd_rw_intr+0x330/0x860 [sd_mod] [<a0000002073b3ac0>] scsi_finish_command+0x100/0x1c0 [scsi_mod] [<a0000002073c2910>] scsi_softirq_done+0x230/0x300 [scsi_mod] [<a000000100277d20>] blk_done_softirq+0x160/0x1c0 [<a000000100083e00>] __do_softirq+0x200/0x240 [<a000000100083eb0>] do_softirq+0x70/0xc0 See report: http://marc.theaimsgroup.com/?l=linux-kernel&m=116599593200888&w=2 flush_workqueue() is not allowed to be called in the softirq context. However, aio_complete() called from I/O interrupt can potentially call put_ioctx with last ref count on ioctx and triggers bug. It is simply incorrect to perform ioctx freeing from aio_complete. The bug is trigger-able from a race between io_destroy() and aio_complete(). A possible scenario: cpu0 cpu1 io_destroy aio_complete wait_for_all_aios { __aio_put_req ... ctx->reqs_active--; if (!ctx->reqs_active) return; } ... put_ioctx(ioctx) put_ioctx(ctx); __put_ioctx bam! Bug trigger! The real problem is that the condition check of ctx->reqs_active in wait_for_all_aios() is incorrect that access to reqs_active is not being properly protected by spin lock. This patch adds that protective spin lock, and at the same time removes all duplicate ref counting for each kiocb as reqs_active is already used as a ref count for each active ioctx. This also ensures that buggy call to flush_workqueue() in softirq context is eliminated. Signed-off-by: "Ken Chen" <kenchen@google.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: Suparna Bhattacharya <suparna@in.ibm.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: <stable@kernel.org> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Fix lock inversion aio_kick_handler()Zach Brown2006-12-301-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | lockdep found a AB BC CA lock inversion in retry-based AIO: 1) The task struct's alloc_lock (A) is acquired in process context with interrupts enabled. An interrupt might arrive and call wake_up() which grabs the wait queue's q->lock (B). 2) When performing retry-based AIO the AIO core registers aio_wake_function() as the wake funtion for iocb->ki_wait. It is called with the wait queue's q->lock (B) held and then tries to add the iocb to the run list after acquiring the ctx_lock (C). 3) aio_kick_handler() holds the ctx_lock (C) while acquiring the alloc_lock (A) via lock_task() and unuse_mm(). Lockdep emits a warning saying that we're trying to connect the irq-safe q->lock to the irq-unsafe alloc_lock via ctx_lock. This fixes the inversion by calling unuse_mm() in the AIO kick handing path after we've released the ctx_lock. As Ben LaHaise pointed out __put_ioctx could set ctx->mm to NULL, so we must only access ctx->mm while we have the lock. Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Suparna Bhattacharya <suparna@in.ibm.com> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Use activate_mm() in fs/aio.c:use_mm()Jeremy Fitzhardinge2006-12-131-1/+1
| | | | | | | | | | | | | | | | | | | activate_mm() is not the right thing to be using in use_mm(). It should be switch_mm(). On normal x86, they're synonymous, but for the Xen patches I'm adding a hook which assumes that activate_mm is only used the first time a new mm is used after creation (I have another hook for dealing with dup_mm). I think this use of activate_mm() is the only place where it could be used a second time on an mm. >From a quick look at the other architectures I think this is OK (most simply implement one in terms of the other), but some are doing some subtly different stuff between the two. Acked-by: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: remove ki_retried debugging memberBenjamin LaHaise2006-12-071-15/+0
| | | | | | | | | | | | | | Remove the ki_retried member from struct kiocb. I think the idea was bounced around a while back, but Arnaldo pointed out another reason that we should dig it up when he pointed out that the last cacheline of struct kiocb only contains 4 bytes. By removing the debugging member, we save more than the 8 byte on 64 bit machines. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Acked-by: Ken Chen <kenneth.w.chen@intel.com> Acked-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: kill pointless ki_nbytes assignment in aio_setup_single_vectorChen, Kenneth W2006-12-071-1/+0
| | | | | | | | | | | | | io_submit_one assigns ki_left = ki_nbytes = iocb->aio_nbytes, then calls down to aio_setup_iocb, then to aio_setup_single_vector. In there, ki_nbytes is reassigned to the same value it got two call stack above it. There is no need to do so. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Acked-by: Zach Brown <zach.brown@oracle.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: remove kmem_cache_tChristoph Lameter2006-12-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace all uses of kmem_cache_t with struct kmem_cache. The patch was generated using the following script: #!/bin/sh # # Replace one string by another in all the kernel sources. # set -e for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do quilt add $file sed -e "1,\$s/$1/$2/g" $file >/tmp/$$ mv /tmp/$$ $file quilt refresh done The script was run like this sh replace kmem_cache_t "struct kmem_cache" Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Merge branch 'master' of ↵David Howells2006-12-051-4/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: drivers/infiniband/core/iwcm.c drivers/net/chelsio/cxgb2.c drivers/net/wireless/bcm43xx/bcm43xx_main.c drivers/net/wireless/prism54/islpci_eth.c drivers/usb/core/hub.h drivers/usb/input/hid-core.c net/core/netpoll.c Fix up merge failures with Linus's head and fix new compilation failures. Signed-Off-By: David Howells <dhowells@redhat.com>
| * BUG_ON conversion for fs/aio.cEric Sesterhenn2006-11-301-4/+2
| | | | | | | | | | | | | | | | | | This patch converts a if () BUG(); construct to BUG_ON(); which occupies less space, uses unlikely and is safer when BUG() is disabled. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* | WorkStruct: Pass the work_struct pointer instead of context dataDavid Howells2006-11-221-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells <dhowells@redhat.com>
* | WorkStruct: Separate delayable and non-delayable events.David Howells2006-11-221-2/+2
|/ | | | | | | | | | | | Separate delayable work items from non-delayable work items be splitting them into a separate structure (delayed_work), which incorporates a work_struct and the timer_list removed from work_struct. The work_struct struct is huge, and this limits it's usefulness. On a 64-bit architecture it's nearly 100 bytes in size. This reduces that by half for the non-delayable type of event. Signed-Off-By: David Howells <dhowells@redhat.com>
* [PATCH] pr_debug: aio: use size_t length modifier in pr_debug format argumentsZach Brown2006-10-031-2/+2
| | | | | | | | aio: use size_t length modifier in pr_debug format arguments Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Add vector AIO supportBadari Pulavarty2006-10-011-54/+117
| | | | | | | | | | | | | | | This work is initially done by Zach Brown to add support for vectored aio. These are the core changes for AIO to support IOCB_CMD_PREADV/IOCB_CMD_PWRITEV. [akpm@osdl.org: huge build fix] Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Vectorize aio_read/aio_write fileop methodsBadari Pulavarty2006-10-011-4/+11
| | | | | | | | | | | | This patch vectorizes aio_read() and aio_write() methods to prepare for collapsing all aio & vectored operations into one interface - which is aio_read()/aio_write(). Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Michael Holzheu <HOLZHEU@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* spelling fixesAndreas Mohr2006-06-261-1/+1
| | | | | | | | | | | | acquired (aquired) contiguous (contigious) successful (succesful, succesfull) surprise (suprise) whether (weather) some other misspellings Signed-off-by: Andreas Mohr <andi@lisas.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] list: use list_replace_init() instead of list_splice_init()Oleg Nesterov2006-06-231-2/+2
| | | | | | | | | | list_splice_init(list, head) does unneeded job if it is known that list_empty(head) == 1. We can use list_replace_init() instead. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] use kzalloc and kcalloc in core fs codeOliver Neukum2006-03-251-2/+1
| | | | | | Signed-off-by: Oliver Neukum <oliver@neukum.name> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] rcu file: use atomic primitivesNick Piggin2006-01-081-2/+1
| | | | | | | | | Use atomic_inc_not_zero for rcu files instead of special case rcuref. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: replace locking comments with assert_spin_locked()Zach Brown2005-11-131-5/+12
| | | | | | | | | aio: replace locking comments with assert_spin_locked() Signed-off-by: Zach Brown <zach.brown@oracle.com> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: remove kioctx from mm_structZach Brown2005-11-131-18/+9
| | | | | | | | | | | | | | | | | | | | | | Sync iocbs have a life cycle that don't need a kioctx. Their retrying, if any, is done in the context of their owner who has allocated them on the stack. The sole user of a sync iocb's ctx reference was aio_complete() checking for an elevated iocb ref count that could never happen. No path which grabs an iocb ref has access to sync iocbs. If we were to implement sync iocb cancelation it would be done by the owner of the iocb using its on-stack reference. Removing this chunk from aio_complete allows us to remove the entire kioctx instance from mm_struct, reducing its size by a third. On a i386 testing box the slab size went from 768 to 504 bytes and from 5 to 8 per page. Signed-off-by: Zach Brown <zach.brown@oracle.com> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: remove aio_max_nr accounting raceZach Brown2005-11-071-10/+21
| | | | | | | | | | | | | | | | | | | | | AIO was adding a new context's max requests to the global total before testing if that resulting total was over the global limit. This let innocent tasks get their new limit tested along with a racing guilty task that was crossing the limit. This serializes the _nr accounting with a spinlock It also switches to using unsigned long for the global totals. Individual contexts are still limited to an unsigned int's worth of requests by the syscall interface. The problem and fix were verified with a simple program that spun creating and destroying a context while holding on to another long lived context. Before the patch a task creating a tiny context could get a spurious EAGAIN if it raced with a task creating a very large context that overran the limit. Signed-off-by: Zach Brown <zach.brown@oracle.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio syscalls are not checked by lsmKostik Belousov2005-10-231-0/+6
| | | | | | | | | | | | | Another case of missing call to security_file_permission: aio functions (namely, io_submit) does not check credentials with security modules. Below is the simple patch to the problem. It seems that it is enough to check for rights at the request submission time. Signed-off-by: Kostik Belousov <kostikbel@gmail.com> Signed-off-by: Chris Wright <chrisw@osdl.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: revert lock_kiocb()Zach Brown2005-10-171-25/+1
| | | | | | | | | | | | | | | lock_kiocb() was introduced to serialize retrying and cancellation. In the process of doing so it tried to sleep waiting for KIF_LOCKED while holding the ctx_lock spinlock. Recent fixes have ensured that multiple concurrent retries won't be attempted for a given iocb. Cancel has other problems and has no significant in-tree users that have been complaining about it. So for the immediate future we'll revert sleeping with the lock held and will address proper cancellation and retry serialization in the future. Signed-off-by: Zach Brown <zach.brown@oracle.com> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: avoid extra aio_{read,write} call when ki_left == 0Zach Brown2005-09-301-2/+2
| | | | | | | | | | | | Recently aio_p{read,write} changed to perform retries internally rather than returning -EIOCBRETRY. This inadvertantly resulted in always calling aio_{read,write} with ki_left at 0 which would in turn immediately return 0. Harmless, but we can avoid this call by checking in the caller. Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: remove unlocked task_list test and resulting raceZach Brown2005-09-301-46/+33
| | | | | | | | | | | | | | | | | | | | | | Only one of the run or kick path is supposed to put an iocb on the run list. If both of them do it than one of them can end up referencing a freed iocb. The kick path could delete the task_list item from the wait queue before getting the ctx_lock and putting the iocb on the run list. The run path was testing the task_list item outside the lock so that it could catch ki_retry methods that return -EIOCBRETRY *without* putting the iocb on a wait queue and promising to call kick_iocb. This unlocked check could then race with the kick path to cause both to try and put the iocb on the run list. The patch stops the run path from testing task_list by requring that any ki_retry that returns -EIOCBRETRY *must* guarantee that kick_iocb() will be called in the future. aio_p{read,write}, the only in-tree -EIOCBRETRY users, are updated. Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: lock around kiocbTryKick()Zach Brown2005-09-301-7/+12
| | | | | | | | | | | | | | | | | | Only one of the run or kick path is supposed to put an iocb on the run list. If both of them do it than one of them can end up referencing a freed iocb. The kick patch could set the Kicked bit before acquiring the ctx_lock and putting the iocb on the run list. The run path, while holding the ctx_lock, could see this partial kick and mistake it for a kick that was deferred while it was doing work with the run_list NULLed out. It would then race with the kick thread to add the iocb to the run list. This patch moves the kick setting under the ctx_lock so that only one of the kick or run path queues the iocb on the run list, as intended. Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Add smp_mb__after_clear_bit() to unlock_kiocb()Zach Brown2005-09-171-0/+1
| | | | | | | | | | | | | | Add smp_mb__after_clear_bit() to unlock_kiocb() AIO's use of wait_on_bit_lock()/wake_up_bit() forgot to add a barrier between clearing its lock bit and calling wake_up_bit() so wake_up_bit()'s unlocked waitqueue_active() can race. This puts AIO's use in line with the others and the comment above wake_up_bit(). Signed-off-by: Zach Brown <zach.brown@oracle.com> Acked-by: Benjamin LaHaise <bcrl@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] files: files struct with RCUDipankar Sarma2005-09-091-1/+2
| | | | | | | | | | | | | | | | | | | | | Patch to eliminate struct files_struct.file_lock spinlock on the reader side and use rcu refcounting rcuref_xxx api for the f_count refcounter. The updates to the fdtable are done by allocating a new fdtable structure and setting files->fdt to point to the new structure. The fdtable structure is protected by RCU thereby allowing lock-free lookup. For fd arrays/sets that are vmalloced, we use keventd to free them since RCU callbacks can't sleep. A global list of fdtable to be freed is not scalable, so we use a per-cpu list. If keventd is already handling the current cpu's work, we use a timer to defer queueing of that work. Since the last publication, this patch has been re-written to avoid using explicit memory barriers and use rcu_assign_pointer(), rcu_dereference() premitives instead. This required that the fd information is kept in a separate structure (fdtable) and updated atomically. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: kiocb locking to serialise retry and cancelBenjamin LaHaise2005-09-091-4/+25
| | | | | | | | | | | | Implement a per-kiocb lock to serialise retry operations and cancel. This is done using wait_on_bit_lock() on the KIF_LOCKED bit of kiocb->ki_flags. Also, make the cancellation path lock the kiocb and subsequently release all references to it if the cancel was successful. This version includes a fix for the deadlock with __aio_run_iocbs. Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] change io_cancel return code for no cancel caseWendy Cheng2005-09-091-1/+1
| | | | | | | | | | | | | | | | Note that other than few exceptions, most of the current filesystem and/or drivers do not have aio cancel specifically defined (kiob->ki_cancel field is mostly NULL). However, sys_io_cancel system call universally sets return code to -EAGAIN. This gives applications a wrong impression that this call is implemented but just never works. We have customer inquires about this issue. Changed by Benjamin LaHaise to EINVAL instead of ENOSYS Signed-off-by: S. Wendy Cheng <wcheng@redhat.com> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: fixes performance regression in activate_mm and thus exec()Paolo 'Blaisorblade' Giarrusso2005-09-051-0/+4
| | | | | | | | | | | | | | | | | | | | | | Normally, activate_mm() is called from exec(), and thus it used to be a no-op because we use a completely new "MM context" on the host (for instance, a new process), and so we didn't need to flush any "TLB entries" (which for us are the set of memory mappings for the host process from the virtual "RAM" file). Kernel threads, instead, are usually handled in a different way. So, when for AIO we call use_mm(), things used to break and so Benjamin implemented activate_mm(). However, that is only needed for AIO, and could slow down exec() inside UML, so be smart: detect being called for AIO (via PF_BORROWED_MM) and do the full flush only in that situation. Comment also the caller so that people won't go breaking UML without noticing. I also rely on the caller's locks for testing current->flags. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> CC: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio-retry-fix: fix aio retry work queueingSébastien Dugu2005-06-281-0/+9
| | | | | | | | | | | | | | | | In the case of buffered AIO, in the aio retry path (aio_run_iocb), when the retry method returns EIOCBRETRY the kicked iocb is added to the context run list but is never queued onto the work queue. The request therefore is never completed. This patch fixes that by adding the appropriate call to aio_queue_work in aio_run_aiocb so that subsequent retries will be handled by the aio worker thread. Signed-off-by: Sébastien Dugué <sebastien.dugue@bull.net> Acked-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: optimize io_submit_one()Ken Chen2005-05-011-4/+8
| | | | | | | | | | | | | | | This patch optimizes io_submit_one to call aio_run_iocb() directly if ctx->run_list is empty. When the list is empty, the operation of adding to the list, then call to __aio_run_iocbs() is unnecessary because these operations are done in one atomic step. ctx->run_list always has only one element in this case. This optimization speeds up industry standard db transaction processing benchmark by 0.2%. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Suparna Bhattacharya <suparna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: clean up debug codeKen Chen2005-05-011-28/+5
| | | | | | | | | | | | Clean up code that was previously used for debug purpose. Remove aio_run, aio_wakeups, iocb->ki_queued and iocb->ki_kicked. Also clean up unused variable count in __aio_run_iocbs() and debug code in read_events(). Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Suparna Bhattacharya <suparna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: ring wrapping simplificationKen Chen2005-05-011-1/+2
| | | | | | | | | | | | Since the tail pointer in aio_ring structure never wrap ring size more than once, so a simple compare is sufficient to wrap the index around. This avoid a more expensive mod operation. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Suparna Bhattacharya <suparna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: remove superfluous kiocb member initializationKen Chen2005-05-011-10/+1
| | | | | | | | | | | | | | | | This patch removes superfluous kiocb member initialization in the AIO allocation and deallocation path. For example, in really_put_req(), right before kiocb is returned to slab, 5 variables are reset to NULL. The same variables will be initialized at the kiocb allocation time, so why bother reset them knowing that they will be set to valid data at alloc time? Another example: ki_retry is initialized in __aio_get_req, but is initialized again in io_submit_one. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Suparna Bhattacharya <suparna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fs/aio.c: make some code staticAdrian Bunk2005-04-251-9/+11
| | | | | | | | This patch makes some needlessly global code static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2Linus Torvalds2005-04-161-0/+1729
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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