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* [PATCH] remove dead code from elevator switchingDave Jones2006-06-23
| | | | | | | | | | We already drop the refcount in elevator_exit(), and as we're setting 'e' to NULL, we'll never take that branch anyway. Finally, as 'e' is a local var that isn't referenced afterwards, setting it to NULL is pointless. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [PATCH] elevator switching raceJens Axboe2006-06-08
| | | | | | | | | | | | | | | | | | | | There's a race between shutting down one io scheduler and firing up the next, in which a new io could enter and cause the io scheduler to be invoked with bad or NULL data. To fix this, we need to maintain the queue lock for a bit longer. Unfortunately we cannot do that, since the elevator init requires to be run without the lock held. This isn't easily fixable, without also changing the mempool API. So split the initialization into two parts, and alloc-init operation and an attach operation. Then we can preallocate the io scheduler and related structures, and run the attach inside the lock after we detach the old one. This patch has survived 30 minutes of 1 second io scheduler switching with a very busy io load. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [BLOCK] limit request_fn recursionJens Axboe2006-05-11
| | | | | | | | | | | | | | | | | Don't recurse back into the driver even if the unplug threshold is met, when the driver asks for a requeue. This is both silly from a logical point of view (requeues typically happen due to driver/hardware shortage), and also dangerous since we could hit an endless request_fn -> requeue -> unplug -> request_fn loop and crash on stack overrun. Also limit blk_run_queue() to one level of recursion, similar to how blk_start_queue() works. This patch fixed a real problem with SLES10 and lpfc, and it could hit any SCSI lld that returns non-zero from it's ->queuecommand() handler. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] block/elevator.c: remove unused exportsAdrian Bunk2006-04-20
| | | | | | | | | | | This patch removes the following unused EXPORT_SYMBOL's: - elv_requeue_request - elv_completed_request They are only used by the block core, hence they need not be exported. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Jens Axboe <axboe@suse.de>
* [PATCH] Don't pass boot parameters to argv_init[]OGAWA Hirofumi2006-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The boot cmdline is parsed in parse_early_param() and parse_args(,unknown_bootoption). And __setup() is used in obsolete_checksetup(). start_kernel() -> parse_args() -> unknown_bootoption() -> obsolete_checksetup() If __setup()'s callback (->setup_func()) returns 1 in obsolete_checksetup(), obsolete_checksetup() thinks a parameter was handled. If ->setup_func() returns 0, obsolete_checksetup() tries other ->setup_func(). If all ->setup_func() that matched a parameter returns 0, a parameter is seted to argv_init[]. Then, when runing /sbin/init or init=app, argv_init[] is passed to the app. If the app doesn't ignore those arguments, it will warning and exit. This patch fixes a wrong usage of it, however fixes obvious one only. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* BUG_ON() Conversion in block/elevator.cEric Sesterhenn2006-03-24
| | | | | | | | this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] Block queue IO tracing support (blktrace) as of 2006-03-23Jens Axboe2006-03-23
| | | | Signed-off-by: Jens Axboe <axboe@suse.de>
* [PATCH] fix rmmod problems with elevator attributes, clean them upAl Viro2006-03-18
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* [PATCH] elevator_t lifetime rules and sysfs fixesAl Viro2006-03-18
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* [PATCH] stop elv_unregister() from rogering other iosched's data, fix lockingAl Viro2006-03-18
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] block: implement elv_insert and use it (fix ordcolor flipping bug)Tejun Heo2006-02-08
| | | | | | | | | | | | | | | | | | | q->ordcolor must only be flipped on initial queueing of a hardbarrier request. Constructing ordered sequence and requeueing used to pass through __elv_add_request() which flips q->ordcolor when it sees a barrier request. This patch separates out elv_insert() from __elv_add_request() and uses elv_insert() when constructing ordered sequence and requeueing. elv_insert() inserts the given request at the specified position and does nothing else. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] block: request_queue->ordcolor must not be flipped on SOFTBARRIERTejun Heo2006-02-05
| | | | | | | | | q->ordcolor must not be flipped on SOFTBARRIER. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [BLOCK] elevator: allow default scheduler to potentially be modularNate Diller2006-01-24
| | | | | | | | | | | | | | | Jens has decided that allowing the default scheduler to be a module is a bug, and should not be allowed under kconfig. However, I find that scenario useful for debugging, and wish for the kernel to be able to handle this situation without OOPSing, if I enable such an option in the .config directly. This patch dynamically checks for the presence of the compiled-in default, and falls back to no-op, emitting a suitable error message, when the default is not available Tested for a range of boot options on 2.6.16-rc1-mm2. Signed-off-by: Nate Diller <nate.diller@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] elevator: default choice selectionNate Diller2006-01-24
| | | | | | | | | | | | | | | | | My previous default iosched patch did a poor job dealing with the 'elevator=' boot-time option. The old behavior falls back to the compiled-in default if the requested one is not registered at boot time. This patch dynamically evaluates which default to use, and emits a suitable error message when the requested scheduler is not available. It also does the 'as' -> 'anticipatory' conversion before elevator registration, which along with a modified registration function, allows it to correctly indicate which default scheduler is in use. Tested for a range of boot options on 2.6.16-rc1-mm2. Signed-off-by: Nate Diller <nate.diller@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] elevator: if specified scheduler is not found, fall back to defaultJens Axboe2006-01-16
| | | | Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] elevator: Make elevator=as work again for anticipatoryChuck Ebbert2006-01-16
| | | | | Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [PATCH] fix queue stalling while barrier sequencingTejun Heo2006-01-12
| | | | | | | | | | | | | | | | | | | If ordered tag isn't supported, request ordering for barrier sequencing is performed by queue draining, which basically hangs the request queue until elv_completed_request() reports completion of all previous fs requests. The condition check in elv_completed_request() was only performed for fs requests. If a special request is queued between the last to-be-drained request and the barrier sequence, draining is never completed and the queue is stalled forever. This patch moves the end-of-draining condition check such that it's performed for all requests. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* make elv_try_merge() static, kill the dead declaration ofCoywolf Qi Hunt2006-01-09
| | | | | | | elv_try_last_merge(). Signed-off-by: Coywolf Qi Hunt <qiyong@fc-cn.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] reimplement handling of barrier requestTejun Heo2006-01-06
| | | | | | | | | | | | Reimplement handling of barrier requests. * Flexible handling to deal with various capabilities of target devices. * Retry support for falling back. * Tagged queues which don't support ordered tag can do ordered. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] add @uptodate to end_that_request_last() and @error to rq_end_io_fn()Tejun Heo2006-01-06
| | | | | | | | | | | | | | | | | add @uptodate argument to end_that_request_last() and @error to rq_end_io_fn(). there's no generic way to pass error code to request completion function, making generic error handling of non-fs request difficult (rq->errors is driver-specific and each driver uses it differently). this patch adds @uptodate to end_that_request_last() and @error to rq_end_io_fn(). for fs requests, this doesn't really matter, so just using the same uptodate argument used in the last call to end_that_request_first() should suffice. imho, this can also help the generic command-carrying request jens is working on. Signed-off-by: tejun heo <htejun@gmail.com> Signed-Off-By: Jens Axboe <axboe@suse.de>
* [BLOCK] new block/ directory comment tidyCoywolf Qi Hunt2005-11-18
| | | | | | | | Some leftover comments referring to drivers/block that are now block/. They don't add any information we don't already have, so kill them. Signed-off-by: Coywolf Qi Hunt <qiyong@fc-cn.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] elevator: elv_latter/former_request updateTejun Heo2005-11-12
| | | | | | | | | | | | With generic dispatch queue update, implicit former/latter request handling using rq->queuelist.prev/next doesn't work as expected anymore. Also, the only iosched dependent on this feature was noop-iosched and it has been reimplemented to have its own latter/former methods. This patch removes implicit former/latter handling. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] fix string handling in elv_iosched_storeTejun Heo2005-11-12
| | | | | | | | | elv_iosched_store doesn't terminate string passed from userspace if it's too long. Also, if the written length is zero (probably not possible), it accesses elevator_name[-1]. This patch fixes both bugs. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] Implement elv_drain_elevator for improved switch error detectionTejun Heo2005-11-12
| | | | | | | | | | | | This patch adds request_queue->nr_sorted which keeps the number of requests in the iosched and implement elv_drain_elevator which performs forced dispatching. elv_drain_elevator checks whether iosched actually dispatches all requests it has and prints error message if it doesn't. As buggy forced dispatching can result in wrong barrier operations, I think this extra check is worthwhile. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] elevator: run queue in elevator_switchTejun Heo2005-11-12
| | | | | | | | elevator_dispatch needs to run queue after forced dispatching; otherwise, the queue might stall. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] elevator init fixes #2Zachary Amsden2005-11-12
| | | | | | | | | In addition to the first patch, which is probably goodness, I found the cause of my panic - applying this patch fixes it and now I am booting. If the chosen_elevator[] is not found, fall back to noop. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] elevator init fixesZachary Amsden2005-11-12
| | | | | | | | | | | | | | | | | | | | | | | | I got a panic in the elevator code, backtrace : Unable to handle kernel NULL pointer dereference at virtual address 00000060 .. EIP is at elevator_put+0x0/0x30 (null elevator_type passed) .. elevator_init+0x38 blk_init_queu_node+0xc9 floppy_init+0xdb do_initcalls+0x23 init+0x10a init+0x0 Clearly if the kmalloc here fails, e->elevator_type is not yet set; this appears to be the correct fix, but I think I probably hit the second case due to a race condition. Someone more familiar with the elevator code should look at this more closely until I can determine if I can reproduce. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jens Axboe <axboe@suse.de>
* [BLOCK] Move all core block layer code to new block/ directoryJens Axboe2005-11-04
drivers/block/ is right now a mix of core and driver parts. Lets move the core parts to a new top level directory. Al will move the fs/ related block parts to block/ next. Signed-off-by: Jens Axboe <axboe@suse.de>
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