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2012-06-01block: fix buffer overflow when printing partition UUIDsTejun Heo
commit 05c69d298c96703741cac9a5cbbf6c53bd55a6e2 upstream. 6d1d8050b4bc8 "block, partition: add partition_meta_info to hd_struct" added part_unpack_uuid() which assumes that the passed in buffer has enough space for sprintfing "%pU" - 37 characters including '\0'. Unfortunately, b5af921ec0233 "init: add support for root devices specified by partition UUID" supplied 33 bytes buffer to the function leading to the following panic with stackprotector enabled. Kernel panic - not syncing: stack-protector: Kernel stack corrupted in: ffffffff81b14c7e [<ffffffff815e226b>] panic+0xba/0x1c6 [<ffffffff81b14c7e>] ? printk_all_partitions+0x259/0x26xb [<ffffffff810566bb>] __stack_chk_fail+0x1b/0x20 [<ffffffff81b15c7e>] printk_all_paritions+0x259/0x26xb [<ffffffff81aedfe0>] mount_block_root+0x1bc/0x27f [<ffffffff81aee0fa>] mount_root+0x57/0x5b [<ffffffff81aee23b>] prepare_namespace+0x13d/0x176 [<ffffffff8107eec0>] ? release_tgcred.isra.4+0x330/0x30 [<ffffffff81aedd60>] kernel_init+0x155/0x15a [<ffffffff81087b97>] ? schedule_tail+0x27/0xb0 [<ffffffff815f4d24>] kernel_thread_helper+0x5/0x10 [<ffffffff81aedc0b>] ? start_kernel+0x3c5/0x3c5 [<ffffffff815f4d20>] ? gs_change+0x13/0x13 Increase the buffer size, remove the dangerous part_unpack_uuid() and use snprintf() directly from printk_all_partitions(). Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Szymon Gruszczynski <sz.gruszczynski@googlemail.com> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-19Block: use a freezable workqueue for disk-event pollingAlan Stern
commit 62d3c5439c534b0e6c653fc63e6d8c67be3a57b1 upstream. This patch (as1519) fixes a bug in the block layer's disk-events polling. The polling is done by a work routine queued on the system_nrt_wq workqueue. Since that workqueue isn't freezable, the polling continues even in the middle of a system sleep transition. Obviously, polling a suspended drive for media changes and such isn't a good thing to do; in the case of USB mass-storage devices it can lead to real problems requiring device resets and even re-enumeration. The patch fixes things by creating a new system-wide, non-reentrant, freezable workqueue and using it for disk-events polling. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-19block: fix __blkdev_get and add_disk race conditionStanislaw Gruszka
commit 9f53d2fe815b4011ff930a7b6db98385d45faa68 upstream. The following situation might occur: __blkdev_get: add_disk: register_disk() get_gendisk() disk_block_events() disk->ev == NULL disk_add_events() __disk_unblock_events() disk->ev != NULL --ev->block Then we unblock events, when they are suppose to be blocked. This can trigger events related block/genhd.c warnings, but also can crash in sd_check_events() or other places. I'm able to reproduce crashes with the following scripts (with connected usb dongle as sdb disk). <snip> DEV=/dev/sdb ENABLE=/sys/bus/usb/devices/1-2/bConfigurationValue function stop_me() { for i in `jobs -p` ; do kill $i 2> /dev/null ; done exit } trap stop_me SIGHUP SIGINT SIGTERM for ((i = 0; i < 10; i++)) ; do while true; do fdisk -l $DEV 2>&1 > /dev/null ; done & done while true ; do echo 1 > $ENABLE sleep 1 echo 0 > $ENABLE done </snip> I use the script to verify patch fixing oops in sd_revalidate_disk http://marc.info/?l=linux-scsi&m=132935572512352&w=2 Without Jun'ichi Nomura patch titled "Fix NULL pointer dereference in sd_revalidate_disk" or this one, script easily crash kernel within a few seconds. With both patches applied I do not observe crash. Unfortunately after some time (dozen of minutes), script will hung in: [ 1563.906432] [<c08354f5>] schedule_timeout_uninterruptible+0x15/0x20 [ 1563.906437] [<c04532d5>] msleep+0x15/0x20 [ 1563.906443] [<c05d60b2>] blk_drain_queue+0x32/0xd0 [ 1563.906447] [<c05d6e00>] blk_cleanup_queue+0xd0/0x170 [ 1563.906454] [<c06d278f>] scsi_free_queue+0x3f/0x60 [ 1563.906459] [<c06d7e6e>] __scsi_remove_device+0x6e/0xb0 [ 1563.906463] [<c06d4aff>] scsi_forget_host+0x4f/0x60 [ 1563.906468] [<c06cd84a>] scsi_remove_host+0x5a/0xf0 [ 1563.906482] [<f7f030fb>] quiesce_and_remove_host+0x5b/0xa0 [usb_storage] [ 1563.906490] [<f7f03203>] usb_stor_disconnect+0x13/0x20 [usb_storage] Anyway I think this patch is some step forward. As drawback, I do not teardown on sysfs file create error, because I do not know how to nullify disk->ev (since it can be used). However add_disk error handling practically does not exist too, and things will work without this sysfs file, except events will not be exported to user space. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-11-11block: make gendisk hold a reference to its queueTejun Heo
commit f992ae801a7dec34a4ed99a6598bbbbfb82af4fb upstream. The following command sequence triggers an oops. # mount /dev/sdb1 /mnt # echo 1 > /sys/class/scsi_device/0\:0\:1\:0/device/delete # umount /mnt general protection fault: 0000 [#1] PREEMPT SMP CPU 2 Modules linked in: Pid: 791, comm: umount Not tainted 3.1.0-rc3-work+ #8 Bochs Bochs RIP: 0010:[<ffffffff810d0879>] [<ffffffff810d0879>] __lock_acquire+0x389/0x1d60 ... Call Trace: [<ffffffff810d2845>] lock_acquire+0x95/0x140 [<ffffffff81aed87b>] _raw_spin_lock+0x3b/0x50 [<ffffffff811573bc>] bdi_lock_two+0x5c/0x70 [<ffffffff811c2f6c>] bdev_inode_switch_bdi+0x4c/0xf0 [<ffffffff811c3fcb>] __blkdev_put+0x11b/0x1d0 [<ffffffff811c4010>] __blkdev_put+0x160/0x1d0 [<ffffffff811c40df>] blkdev_put+0x5f/0x190 [<ffffffff8118f18d>] kill_block_super+0x4d/0x80 [<ffffffff8118f4a5>] deactivate_locked_super+0x45/0x70 [<ffffffff8119003a>] deactivate_super+0x4a/0x70 [<ffffffff811ac4ad>] mntput_no_expire+0xed/0x130 [<ffffffff811acf2e>] sys_umount+0x7e/0x3a0 [<ffffffff81aeeeab>] system_call_fastpath+0x16/0x1b This is because bdev holds on to disk but disk doesn't pin the associated queue. If a SCSI device is removed while the device is still open, the sdev puts the base reference to the queue on release. When the bdev is finally released, the associated queue is already gone along with the bdi and bdev_inode_switch_bdi() ends up dereferencing already freed bdi. Even if it were not for this bug, disk not holding onto the associated queue is very unusual and error-prone. Fix it by making add_disk() take an extra reference to its queue and put it on disk_release() and ensuring that disk and its fops owner are put in that order after all accesses to the disk and queue are complete. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-06-09block: make disk_block_events() properly wait for work cancellationTejun Heo
disk_block_events() should guarantee that the event work is not in flight on return and once blocked it shouldn't issue further cancellations. Because there was no synchronization between the first blocker doing cancel_delayed_work_sync() and the following blockers, the following blockers could finish before cancellation was complete, which broke both guarantees - event work could be in flight and cancellation could happen after return. This bug triggered WARN_ON_ONCE() in disk_clear_events() reported in bug#34662. https://bugzilla.kernel.org/show_bug.cgi?id=34662 Fix it by adding an outer mutex which protects both block count manipulation and work cancellation. -v2: Use outer mutex instead of bit waitqueue per Linus. Signed-off-by: Tejun Heo <tj@kernel.org> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com> Reported-by: Borislav Petkov <bp@alien8.de> Reported-by: Meelis Roos <mroos@linux.ee> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-06-09block: remove non-syncing __disk_block_events() and fold it into ↵Tejun Heo
disk_block_events() After the previous update to disk_check_events(), nobody is using non-syncing __disk_block_events(). Remove @sync and, as this makes __disk_block_events() virtually identical to disk_block_events(), remove the underscore prefixed version. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-06-09block: don't use non-syncing event blocking in disk_check_events()Tejun Heo
This patch is part of fix for triggering of WARN_ON_ONCE() in disk_clear_events() reported in bug#34662. https://bugzilla.kernel.org/show_bug.cgi?id=34662 disk_clear_events() blocks events, schedules and flushes the event work. It expects the work to have started execution on schedule and finished on return from flush. WARN_ON_ONCE() triggers if the event work hasn't executed as expected. This problem happens because __disk_block_events() fails to guarantee that the event work item is not in flight on return from the function in race-free manner. The problem is two-fold and this patch addresses one of them. When __disk_block_events() is called with @sync == %false, it bumps event block count, calls cancel_delayed_work() and return. This makes it impossible to guarantee that event polling is not in flight on return from syncing __disk_block_events() - if the first blocker was non-syncing, polling could still be in progress and later syncing ones would assume that the first blocker already canceled it. Making __disk_block_events() cancel_sync regardless of block count isn't feasible either as it may race with forced event checking in disk_clear_events(). As disk_check_events() is the only user of non-syncing __disk_block_events(), updating it to directly cancel and schedule event work is the easiest way to solve the issue. Note that there's another bug in __disk_block_events() and this patch doesn't fix the issue completely. Later patch will fix the other bug. Signed-off-by: Tejun Heo <tj@kernel.org> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com> Reported-by: Borislav Petkov <bp@alien8.de> Reported-by: Meelis Roos <mroos@linux.ee> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-05-26block: always allocate genhd->ev if check_events is implementedTejun Heo
9fd097b149 (block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers) removed DISK_EVENT_MEDIA_CHANGE from legacy/fringe block drivers which have inadequate ->check_events(). Combined with earlier change 7c88a168da (block: don't propagate unlisted DISK_EVENTs to userland), this enables using ->check_events() for internal processing while avoiding enabling in-kernel block event polling which can lead to infinite event loop. Unfortunately, this made many drivers including floppy without any bit set in disk->events and ->async_events in which case disk_add_events() simply skipped allocation of disk->ev, which disables whole event handling. As ->check_events() is still used during open processing for revalidation, this can lead to open failure. This patch always allocates disk->ev if ->check_events is implemented. In the long term, it would make sense to simply include the event structure inline into genhd as it's now used by virtually all block devices. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Ondrej Zary <linux@rainbow-software.org> Reported-by: Alex Villacis Lasso <avillaci@ceibo.fiec.espol.edu.ec> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-21block: don't propagate unlisted DISK_EVENTs to userlandTejun Heo
DISK_EVENT_MEDIA_CHANGE is used for both userland visible event and internal event for revalidation of removeable devices. Some legacy drivers don't implement proper event detection and continuously generate events under certain circumstances. For example, ide-cd generates media changed continuously if there's no media in the drive, which can lead to infinite loop of events jumping back and forth between the driver and userland event handler. This patch updates disk event infrastructure such that it never propagates events not listed in disk->events to userland. Those events are processed the same for internal purposes but uevent generation is suppressed. This also ensures that userland only gets events which are advertised in the @events sysfs node lowering risk of confusion. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-09block: Don't implicitly trigger event check on disk_unblock_events()Tejun Heo
Currently, disk_unblock_events() implicitly kick event check if the block count reaches zero. This behavior is not described in the comment and hinders with future changes. Make the unblocker explicitly check events by calling disk_check_events() as necessary. This patch doesn't cause any behavior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kay Sievers <kay.sievers@vrfy.org>
2011-03-04Merge branch 'for-linus' of ../linux-2.6-block into block-for-2.6.39/coreTejun Heo
This merge creates two set of conflicts. One is simple context conflicts caused by removal of throtl_scheduled_delayed_work() in for-linus and removal of throtl_shutdown_timer_wq() in for-2.6.39/core. The other is caused by commit 255bb490c8 (block: blk-flush shouldn't call directly into q->request_fn() __blk_run_queue()) in for-linus crashing with FLUSH reimplementation in for-2.6.39/core. The conflict isn't trivial but the resolution is straight-forward. * __blk_run_queue() calls in flush_end_io() and flush_data_end_io() should be called with @force_kblockd set to %true. * elv_insert() in blk_kick_flush() should use %ELEVATOR_INSERT_REQUEUE. Both changes are to avoid invoking ->request_fn() directly from request completion path and closely match the changes in the commit 255bb490c8. Signed-off-by: Tejun Heo <tj@kernel.org>
2011-03-02block/genhd: Change some numerals into macrosLiu Yuan
Rename the numerals in the diskstats_show() into the macros. Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Liu Yuan <tailai.ly@taobao.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-02-24Fix over-zealous flush_disk when changing device size.NeilBrown
There are two cases when we call flush_disk. In one, the device has disappeared (check_disk_change) so any data will hold becomes irrelevant. In the oter, the device has changed size (check_disk_size_change) so data we hold may be irrelevant. In both cases it makes sense to discard any 'clean' buffers, so they will be read back from the device if needed. In the former case it makes sense to discard 'dirty' buffers as there will never be anywhere safe to write the data. In the second case it *does*not* make sense to discard dirty buffers as that will lead to file system corruption when you simply enlarge the containing devices. flush_disk calls __invalidate_devices. __invalidate_device calls both invalidate_inodes and invalidate_bdev. invalidate_inodes *does* discard I_DIRTY inodes and this does lead to fs corruption. invalidate_bev *does*not* discard dirty pages, but I don't really care about that at present. So this patch adds a flag to __invalidate_device (calling it __invalidate_device2) to indicate whether dirty buffers should be killed, and this is passed to invalidate_inodes which can choose to skip dirty inodes. flusk_disk then passes true from check_disk_change and false from check_disk_size_change. dm avoids tripping over this problem by calling i_size_write directly rathher than using check_disk_size_change. md does use check_disk_size_change and so is affected. This regression was introduced by commit 608aeef17a which causes check_disk_size_change to call flush_disk, so it is suitable for any kernel since 2.6.27. Cc: stable@kernel.org Acked-by: Jeff Moyer <jmoyer@redhat.com> Cc: Andrew Patterson <andrew.patterson@hp.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-13Merge branch 'for-2.6.38/event-handling' into for-2.6.38/coreJens Axboe
2011-01-07block: add internal hd part table referencesJens Axboe
We can't use krefs since it's apparently restricted to very basic reference counting. This reverts commit e4a683c8. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-05block: fix accounting bug on cross partition mergesJerome Marchand
/proc/diskstats would display a strange output as follows. $ cat /proc/diskstats |grep sda 8 0 sda 90524 7579 102154 20464 0 0 0 0 0 14096 20089 8 1 sda1 19085 1352 21841 4209 0 0 0 0 4294967064 15689 4293424691 ~~~~~~~~~~ 8 2 sda2 71252 3624 74891 15950 0 0 0 0 232 23995 1562390 8 3 sda3 54 487 2188 92 0 0 0 0 0 88 92 8 4 sda4 4 0 8 0 0 0 0 0 0 0 0 8 5 sda5 81 2027 2130 138 0 0 0 0 0 87 137 Its reason is the wrong way of accounting hd_struct->in_flight. When a bio is merged into a request belongs to different partition by ELEVATOR_FRONT_MERGE. The detailed root cause is as follows. Assuming that there are two partition, sda1 and sda2. 1. A request for sda2 is in request_queue. Hence sda1's hd_struct->in_flight is 0 and sda2's one is 1. | hd_struct->in_flight --------------------------- sda1 | 0 sda2 | 1 --------------------------- 2. A bio belongs to sda1 is issued and is merged into the request mentioned on step1 by ELEVATOR_BACK_MERGE. The first sector of the request is changed from sda2 region to sda1 region. However the two partition's hd_struct->in_flight are not changed. | hd_struct->in_flight --------------------------- sda1 | 0 sda2 | 1 --------------------------- 3. The request is finished and blk_account_io_done() is called. In this case, sda2's hd_struct->in_flight, not a sda1's one, is decremented. | hd_struct->in_flight --------------------------- sda1 | -1 sda2 | 1 --------------------------- The patch fixes the problem by caching the partition lookup inside the request structure, hence making sure that the increment and decrement will always happen on the same partition struct. This also speeds up IO with accounting enabled, since it cuts down on the number of lookups we have to do. Also add a refcount to struct hd_struct to keep the partition in memory as long as users exist. We use kref_test_and_get() to ensure we don't add a reference to a partition which is going away. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-17fs/block: type signature of major_to_index(int) to major_to_index(unsigned)Yang Zhang
The major/minor device numbers are always defined and used as `unsigned'. Signed-off-by: Yang Zhang <kthreadd@gmail.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-17block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)Yang Zhang
Signed-off-by: Yang Zhang <kthreadd@gmail.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-16implement in-kernel gendisk events handlingTejun Heo
Currently, media presence polling for removeable block devices is done from userland. There are several issues with this. * Polling is done by periodically opening the device. For SCSI devices, the command sequence generated by such action involves a few different commands including TEST_UNIT_READY. This behavior, while perfectly legal, is different from Windows which only issues single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some ATAPI devices lock up after being periodically queried such command sequences. * There is no reliable and unintrusive way for a userland program to tell whether the target device is safe for media presence polling. For example, polling for media presence during an on-going burning session can make it fail. The polling program can avoid this by opening the device with O_EXCL but then it risks making a valid exclusive user of the device fail w/ -EBUSY. * Userland polling is unnecessarily heavy and in-kernel implementation is lighter and better coordinated (workqueue, timer slack). This patch implements framework for in-kernel disk event handling, which includes media presence polling. * bdops->check_events() is added, which supercedes ->media_changed(). It should check whether there's any pending event and return if so. Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be called parallelly. * gendisk->events and ->async_events are added. These should be initialized by block driver before passing the device to add_disk(). The former contains the mask of all supported events and the latter the mask of all events which the device can report without polling. /sys/block/*/events[_async] export these to userland. * Kernel parameter block.events_dfl_poll_msecs controls the system polling interval (default is 0 which means disable) and /sys/block/*/events_poll_msecs control polling intervals for individual devices (default is -1 meaning use system setting). Note that if a device can report all supported events asynchronously and its polling interval isn't explicitly set, the device won't be polled regardless of the system polling interval. * If a device is opened exclusively with write access, event checking is automatically disabled until all write exclusive accesses are released. * There are event 'clearing' events. For example, both of currently defined events are cleared after the device has been successfully opened. This information is passed to ->check_events() callback using @clearing argument as a hint. * Event checking is always performed from system_nrt_wq and timer slack is set to 25% for polling. * Nothing changes for drivers which implement ->media_changed() but not ->check_events(). Going forward, all drivers will be converted to ->check_events() and ->media_change() will be dropped. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-16block: move register_disk() and del_gendisk() to block/genhd.cTejun Heo
There's no reason for register_disk() and del_gendisk() to be in fs/partitions/check.c. Move both to genhd.c. While at it, collapse unlink_gendisk(), which was artificially in a separate function due to genhd.c / check.c split, into del_gendisk(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-16block: kill genhd_media_change_notify()Tejun Heo
There's no user of the facility. Kill it. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-24Revert "block: fix accounting bug on cross partition merges"Jens Axboe
This reverts commit 7681bfeeccff5efa9eb29bf09249a3c400b15327. Conflicts: include/linux/genhd.h It has numerous issues with the cleanup path and non-elevator devices. Revert it for now so we can come up with a clean version without rushing things. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (31 commits) driver core: Display error codes when class suspend fails Driver core: Add section count to memory_block struct Driver core: Add mutex for adding/removing memory blocks Driver core: Move find_memory_block routine hpilo: Despecificate driver from iLO generation driver core: Convert link_mem_sections to use find_memory_block_hinted. driver core: Introduce find_memory_block_hinted which utilizes kset_find_obj_hinted. kobject: Introduce kset_find_obj_hinted. driver core: fix build for CONFIG_BLOCK not enabled driver-core: base: change to new flag variable sysfs: only access bin file vm_ops with the active lock sysfs: Fail bin file mmap if vma close is implemented. FW_LOADER: fix kconfig dependency warning on HOTPLUG uio: Statically allocate uio_class and use class .dev_attrs. uio: Support 2^MINOR_BITS minors uio: Cleanup irq handling. uio: Don't clear driver data uio: Fix lack of locking in init_uio_class SYSFS: Allow boot time switching between deprecated and modern sysfs layout driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devices ...
2010-10-22SYSFS: Allow boot time switching between deprecated and modern sysfs layoutAndi Kleen
I have some systems which need legacy sysfs due to old tools that are making assumptions that a directory can never be a symlink to another directory, and it's a big hazzle to compile separate kernels for them. This patch turns CONFIG_SYSFS_DEPRECATED into a run time option that can be switched on/off the kernel command line. This way the same binary can be used in both cases with just a option on the command line. The old CONFIG_SYSFS_DEPRECATED_V2 option is still there to set the default. I kept the weird name to not break existing config files. Also the compat code can be still completely disabled by undefining CONFIG_SYSFS_DEPRECATED_SWITCH -- just the optimizer takes care of this now instead of lots of ifdefs. This makes the code look nicer. v2: This is an updated version on top of Kay's patch to only handle the block devices. I tested it on my old systems and that seems to work. Cc: axboe@kernel.dk Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-19block: fix accounting bug on cross partition mergesYasuaki Ishimatsu
/proc/diskstats would display a strange output as follows. $ cat /proc/diskstats |grep sda 8 0 sda 90524 7579 102154 20464 0 0 0 0 0 14096 20089 8 1 sda1 19085 1352 21841 4209 0 0 0 0 4294967064 15689 4293424691 ~~~~~~~~~~ 8 2 sda2 71252 3624 74891 15950 0 0 0 0 232 23995 1562390 8 3 sda3 54 487 2188 92 0 0 0 0 0 88 92 8 4 sda4 4 0 8 0 0 0 0 0 0 0 0 8 5 sda5 81 2027 2130 138 0 0 0 0 0 87 137 Its reason is the wrong way of accounting hd_struct->in_flight. When a bio is merged into a request belongs to different partition by ELEVATOR_FRONT_MERGE. The detailed root cause is as follows. Assuming that there are two partition, sda1 and sda2. 1. A request for sda2 is in request_queue. Hence sda1's hd_struct->in_flight is 0 and sda2's one is 1. | hd_struct->in_flight --------------------------- sda1 | 0 sda2 | 1 --------------------------- 2. A bio belongs to sda1 is issued and is merged into the request mentioned on step1 by ELEVATOR_BACK_MERGE. The first sector of the request is changed from sda2 region to sda1 region. However the two partition's hd_struct->in_flight are not changed. | hd_struct->in_flight --------------------------- sda1 | 0 sda2 | 1 --------------------------- 3. The request is finished and blk_account_io_done() is called. In this case, sda2's hd_struct->in_flight, not a sda1's one, is decremented. | hd_struct->in_flight --------------------------- sda1 | -1 sda2 | 1 --------------------------- The patch fixes the problem by caching the partition lookup inside the request structure, hence making sure that the increment and decrement will always happen on the same partition struct. This also speeds up IO with accounting enabled, since it cuts down on the number of lookups we have to do. When reloading partition tables, quiesce IO to ensure that no request references to the partition struct exists. When it is safe to free the partition table, the IO for that device is restarted again. Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-16block: Fix race during disk initializationSigned-off-by: Jan Kara
When a new disk is being discovered, add_disk() first ties the bdev to gendisk (via register_disk()->blkdev_get()) and only after that calls bdi_register_bdev(). Because register_disk() also creates disk's kobject, it can happen that userspace manages to open and modify the device's data (or inode) before its BDI is properly initialized leading to a warning in __mark_inode_dirty(). Fix the problem by registering BDI early enough. This patch addresses https://bugzilla.kernel.org/show_bug.cgi?id=16312 Cc: stable@kernel.org Reported-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-15init: add support for root devices specified by partition UUIDWill Drewry
This is the third patch in a series which adds support for storing partition metadata, optionally, off of the hd_struct. One major use for that data is being able to resolve partition by other identities than just the index on a block device. Device enumeration varies by platform and there's a benefit to being able to use something like EFI GPT's GUIDs to determine the correct block device and partition to mount as the root. This change adds that support to root= by adding support for the following syntax: root=PARTUUID=hex-uuid Signed-off-by: Will Drewry <wad@chromium.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-15block, partition: add partition_meta_info to hd_structWill Drewry
I'm reposting this patch series as v4 since there have been no additional comments, and I cleaned up one extra bit of unneeded code (in 3/3). The patches are against Linus's tree: 2bfc96a127bc1cc94d26bfaa40159966064f9c8c (2.6.36-rc3). Would this patchset be suitable for inclusion in an mm branch? This changes adds a partition_meta_info struct which itself contains a union of structures that provide partition table specific metadata. This change leaves the union empty. The subsequent patch includes an implementation for CONFIG_EFI_PARTITION-based metadata. Signed-off-by: Will Drewry <wad@chromium.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-05-21block: remove all rcu head initializationsPaul E. McKenney
Remove all rcu head inits. We don't care about the RCU head state before passing it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can keep track of objects on stack. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-15blkio: fix for modular blk-cgroup buildDivyesh Shah
After merging the block tree, 20100414's linux-next build (x86_64 allmodconfig) failed like this: ERROR: "get_gendisk" [block/blk-cgroup.ko] undefined! ERROR: "sched_clock" [block/blk-cgroup.ko] undefined! This happens because the two symbols aren't exported and hence not available when blk-cgroup code is built as a module. I've tried to stay consistent with the use of EXPORT_SYMBOL or EXPORT_SYMBOL_GPL with the other symbols in the respective files. Signed-off-by: Divyesh Shah <dpshah@google.com> Acked-by: Gui Jianfeng <guijianfeng@cn.fujitsu.cn> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-01-11block: Fix discard alignment calculation and printingMartin K. Petersen
Discard alignment reporting for partitions was incorrect. Update to match the algorithm used elsewhere. The alignment can be negative (misaligned). Fix format string accordingly. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-11-10block: Expose discard granularityMartin K. Petersen
While SSDs track block usage on a per-sector basis, RAID arrays often have allocation blocks that are bigger. Allow the discard granularity and alignment to be set and teach the topology stacking logic how to handle them. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-10-06block: Seperate read and write statistics of in_flight requests v2Nikanth Karthikesan
Commit a9327cac440be4d8333bba975cbbf76045096275 added seperate read and write statistics of in_flight requests. And exported the number of read and write requests in progress seperately through sysfs. But Corrado Zoccolo <czoccolo@gmail.com> reported getting strange output from "iostat -kx 2". Global values for service time and utilization were garbage. For interval values, utilization was always 100%, and service time is higher than normal. So this was reverted by commit 0f78ab9899e9d6acb09d5465def618704255963b The problem was in part_round_stats_single(), I missed the following: if (now == part->stamp) return; - if (part->in_flight) { + if (part_in_flight(part)) { __part_stat_add(cpu, part, time_in_queue, part_in_flight(part) * (now - part->stamp)); __part_stat_add(cpu, part, io_ticks, (now - part->stamp)); With this chunk included, the reported regression gets fixed. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> -- Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-10-04Revert "Seperate read and write statistics of in_flight requests"Jens Axboe
This reverts commit a9327cac440be4d8333bba975cbbf76045096275. Corrado Zoccolo <czoccolo@gmail.com> reports: "with 2.6.32-rc1 I started getting the following strange output from "iostat -kx 2": Linux 2.6.31bisect (et2) 04/10/2009 _i686_ (2 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 10,70 0,00 3,16 15,75 0,00 70,38 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 18,22 0,00 0,67 0,01 14,77 0,02 43,94 0,01 10,53 39043915,03 2629219,87 sdb 60,89 9,68 50,79 3,04 1724,43 50,52 65,95 0,70 13,06 488437,47 2629219,87 avg-cpu: %user %nice %system %iowait %steal %idle 2,72 0,00 0,74 0,00 0,00 96,53 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 sdb 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 avg-cpu: %user %nice %system %iowait %steal %idle 6,68 0,00 0,99 0,00 0,00 92,33 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 sdb 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 avg-cpu: %user %nice %system %iowait %steal %idle 4,40 0,00 0,73 1,47 0,00 93,40 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 sdb 0,00 4,00 0,00 3,00 0,00 28,00 18,67 0,06 19,50 333,33 100,00 Global values for service time and utilization are garbage. For interval values, utilization is always 100%, and service time is higher than normal. I bisected it down to: [a9327cac440be4d8333bba975cbbf76045096275] Seperate read and write statistics of in_flight requests and verified that reverting just that commit indeed solves the issue on 2.6.32-rc1." So until this is debugged, revert the bad commit. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-19Driver-Core: extend devnode callbacks to provide permissionsKay Sievers
This allows subsytems to provide devtmpfs with non-default permissions for the device node. Instead of the default mode of 0600, null, zero, random, urandom, full, tty, ptmx now have a mode of 0666, which allows non-privileged processes to access standard device nodes in case no other userspace process applies the expected permissions. This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15driver model: constify attribute groupsDavid Brownell
Let attribute group vectors be declared "const". We'd like to let most attribute metadata live in read-only sections... this is a start. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-14Seperate read and write statistics of in_flight requestsNikanth Karthikesan
Currently, there is a single in_flight counter measuring the number of requests in the request_queue. But some monitoring tools would like to know how many read requests and write requests are in progress. Split the current in_flight counter into two seperate counters for read and write. This information is exported as a sysfs attribute, as changing the currently available stat files would break the existing tools. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11Send uevents for write_protect changesHannes Reinecke
Whenever a block device changes it's read-only attribute notify the userspace about it. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-15Driver Core: block: add nodename support for block drivers.Kay Sievers
This adds support for block drivers to report their requested nodename to userspace. It also updates a number of block drivers to provide the needed subdirectory and device name to be used for them. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-22block: Export I/O topology for block devices and partitionsMartin K. Petersen
To support devices with physical block sizes bigger than 512 bytes we need to ensure proper alignment. This patch adds support for exposing I/O topology characteristics as devices are stacked. logical_block_size is the smallest unit the device can address. physical_block_size indicates the smallest I/O the device can write without incurring a read-modify-write penalty. The io_min parameter is the smallest preferred I/O size reported by the device. In many cases this is the same as the physical block size. However, the io_min parameter can be scaled up when stacking (RAID5 chunk size > physical block size). The io_opt characteristic indicates the optimal I/O size reported by the device. This is usually the stripe width for arrays. The alignment_offset parameter indicates the number of bytes the start of the device/partition is offset from the device's natural alignment. Partition tools and MD/DM utilities can use this to pad their offsets so filesystems start on proper boundaries. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-22block: include empty disks in /proc/diskstatsTejun Heo
/proc/diskstats used to show stats for all disks whether they're zero-sized or not and their non-zero partitions. Commit 074a7aca7afa6f230104e8e65eba3420263714a5 accidentally changed the behavior such that it doesn't print out zero sized disks. This patch implements DISK_PITER_INCL_EMPTY_PART0 flag to partition iterator and uses it in diskstats_show() such that empty part0 is shown in /proc/diskstats. Reported and bisectd by Dianel Collins. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Daniel Collins <solemnwarning@solemnwarning.no-ip.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-26block: add documentation for register_blkdev()Márton Németh
Add documentation for register_blkdev() function and for the parameters. Signed-off-by: Márton Németh <nm127@freemail.hu> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-18block: fix booting from partitioned md arrayNeil Brown
Hi Tejun, it looks like your commit: block: don't depend on consecutive minor space f331c0296f2a9fee0d396a70598b954062603015 broke a particular case for booting from partitioned md/raid devices. That is the second time this has been broken recently. The previous time was fixed by block: do_mounts - accept root=<non-existant partition> 30f2f0eb4bd2c43d10a8b0d872c6e5ad8f31c9a0 Because the data isn't available when an md device is first created (we add disks and set it up after creation), the initial partition scan finds nothing. It is not until the device is opened that another partition scan happens and finds something. So at the point where the kernel parameter "root=/dev/md_d0p1" is being parsed, md_d0 exists, but md_d0p1 does not. However if we let blk_lookup_devt return the correct device number even though the device doesn't exist, then the attempt to mount it will successfully find the partition. I have tried in the past to find a way to get the partition table to be read as soon as the array is assembled but that proved impossible (at the time). I don't remember the details, and could possibly revisit it. However it would be really nice if blk_lookup_devt could be adjusted to again accept non existant partitions. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-06block: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers
Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-12-29block: add one-hit cache for disk partition lookupJens Axboe
disk_map_sector_rcu() returns a partition from a sector offset, which we use for IO statistics on a per-partition basis. The lookup itself is an O(N) list lookup, where N is the number of partitions. This actually hurts performance quite a bit, even on the lower end partitions. On higher numbered partitions, it can get pretty bad. Solve this by adding a one-hit cache for partition lookup. This makes the lookup O(1) for the case where we do most IO to one partition. Even for mixed partition workloads, amortized cost is pretty close to O(1) since the natural IO batching makes the one-hit cache last for lots of IOs. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-03block: set disk->node_id before it's being usedCheng Renquan
disk->node_id will be refered in allocating in disk_expand_part_tbl, so we should set it before disk->node_id is refered. Signed-off-by: Cheng Renquan <crquan@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-11-18block: fix boot failure with CONFIG_DEBUG_BLOCK_EXT_DEVT=y and nashZhang, Yanmin
We run into system boot failure with kernel 2.6.28-rc. We found it on a couple of machines, including T61 notebook, nehalem machine, and another HPC NX6325 notebook. All the machines use FedoraCore 8 or FedoraCore 9. With kernel prior to 2.6.28-rc, system boot doesn't fail. I debug it and locate the root cause. Pls. see http://bugzilla.kernel.org/show_bug.cgi?id=11899 https://bugzilla.redhat.com/show_bug.cgi?id=471517 As a matter of fact, there are 2 bugs. 1)root=/dev/sda1, system boot randomly fails. Mostly, boot for 5 times and fails once. nash has a bug. Some of its functions misuse return value 0. Sometimes, 0 means timeout and no uevent available. Sometimes, 0 means nash gets an uevent, but the uevent isn't block-related (for exmaple, usb). If by coincidence, kernel tells nash that uevents are available, but kernel also set timeout, nash might stops collecting other uevents in queue if current uevent isn't block-related. I work out a patch for nash to fix it. http://bugzilla.kernel.org/attachment.cgi?id=18858 2) root=LABEL=/, system always can't boot. initrd init reports switchroot fails. Here is an executation branch of nash when booting: (1) nash read /sys/block/sda/dev; Assume major is 8 (on my desktop) (2) nash query /proc/devices with the major number; It found line "8 sd"; (3) nash use 'sd' to search its own probe table to find device (DISK) type for the device and add it to its own list; (4) Later on, it probes all devices in its list to get filesystem labels; scsi register "8 sd" always. When major is 259, nash fails to find the device(DISK) type. I enables CONFIG_DEBUG_BLOCK_EXT_DEVT=y when compiling kernel, so 259 is picked up for device /dev/sda1, which causes nash to fail to find device (DISK) type. To fixing issue 2), I create a patch for nash and another patch for kernel. http://bugzilla.kernel.org/attachment.cgi?id=18859 http://bugzilla.kernel.org/attachment.cgi?id=18837 Below is the patch for kernel 2.6.28-rc4. It registers blkext, a new block device in proc/devices. With 2 patches on nash and 1 patch on kernel, I boot my machines for dozens of times without failure. Signed-off-by Zhang Yanmin <yanmin.zhang@linux.intel.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-23proc: move /proc/diskstats boilerplate to block/genhd.cAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-23proc: move rest of /proc/partitions code to block/genhd.cAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Jens Axboe <jens.axboe@oracle.com>