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* Merge branch 'for-2.6.38/event-handling' into for-2.6.38/coreJens Axboe2011-01-13
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| * implement in-kernel gendisk events handlingTejun Heo2010-12-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * block: move register_disk() and del_gendisk() to block/genhd.cTejun Heo2010-12-16
| | | | | | | | | | | | | | | | | | | | 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>
| * block: kill genhd_media_change_notify()Tejun Heo2010-12-16
| | | | | | | | | | | | | | 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>
* | block: add internal hd part table referencesJens Axboe2011-01-07
| | | | | | | | | | | | | | | | | | 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>
* | block: fix accounting bug on cross partition mergesJerome Marchand2011-01-05
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | /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>
* Revert "block: fix accounting bug on cross partition merges"Jens Axboe2010-10-24
| | | | | | | | | | | | | | 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>
* Merge branch 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2010-10-22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-block: (39 commits) cfq-iosched: Fix a gcc 4.5 warning and put some comments block: Turn bvec_k{un,}map_irq() into static inline functions block: fix accounting bug on cross partition merges block: Make the integrity mapped property a bio flag block: Fix double free in blk_integrity_unregister block: Ensure physical block size is unsigned int blkio-throttle: Fix possible multiplication overflow in iops calculations blkio-throttle: limit max iops value to UINT_MAX blkio-throttle: There is no need to convert jiffies to milli seconds blkio-throttle: Fix link failure failure on i386 blkio: Recalculate the throttled bio dispatch time upon throttle limit change blkio: Add root group to td->tg_list blkio: deletion of a cgroup was causes oops blkio: Do not export throttle files if CONFIG_BLK_DEV_THROTTLING=n block: set the bounce_pfn to the actual DMA limit rather than to max memory block: revert bad fix for memory hotplug causing bounces Fix compile error in blk-exec.c for !CONFIG_DETECT_HUNG_TASK block: set the bounce_pfn to the actual DMA limit rather than to max memory block: Prevent hang_check firing during long I/O cfq: improve fsync performance for small files ... Fix up trivial conflicts due to __rcu sparse annotation in include/linux/genhd.h
| * block: fix accounting bug on cross partition mergesYasuaki Ishimatsu2010-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | /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>
| * block, partition: add partition_meta_info to hd_structWill Drewry2010-09-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | kernel: __rcu annotationsArnd Bergmann2010-08-19
|/ | | | | | | | | | | This adds annotations for RCU operations in core kernel components Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
* Remove GENHD_FL_DRIVERFSNeilBrown2010-03-16
| | | | | | | | | | | | This flag is not used, so best discarded. Signed-off-by: NeilBrown <neilb@suse.de> -- Hi Jens, I came across this recently - these are the only two occurances of "GENHD_FL_DRIVERFS" in the kernel, so it cannot be needed. NeilBrown Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* percpu: add __percpu sparse annotations to core kernel subsystemsTejun Heo2010-02-16
| | | | | | | | | | | | | | | | | | | Add __percpu sparse annotations to core subsystems. These annotations are to make sparse consider percpu variables to be in a different address space and warn if accessed without going through percpu accessors. This patch doesn't affect normal builds. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-mm@kvack.org Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Eric Biederman <ebiederm@xmission.com>
* genhd: overlapping variable definitionStephen Hemminger2010-01-11
| | | | | | | | | | | This fixes the sparse warning: fs/ext4/super.c:2390:40: warning: symbol 'i' shadows an earlier one fs/ext4/super.c:2368:22: originally declared here Using 'i' in a macro is dubious practice. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Expose discard granularityMartin K. Petersen2009-11-10
| | | | | | | | | | 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>
* block: Seperate read and write statistics of in_flight requests v2Nikanth Karthikesan2009-10-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Revert "Seperate read and write statistics of in_flight requests"Jens Axboe2009-10-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* const: make block_device_operations constAlexey Dobriyan2009-09-22
| | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Driver-Core: extend devnode callbacks to provide permissionsKay Sievers2009-09-19
| | | | | | | | | | | | | 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>
* Seperate read and write statistics of in_flight requestsNikanth Karthikesan2009-09-14
| | | | | | | | | | | | | 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>
* Driver Core: block: add nodename support for block drivers.Kay Sievers2009-06-16
| | | | | | | | | | 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>
* Merge branch 'for-2.6.31' of ↵Linus Torvalds2009-06-12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6 * 'for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (29 commits) ide: re-implement ide_pci_init_one() on top of ide_pci_init_two() ide: unexport ide_find_dma_mode() ide: fix PowerMac bootup oops ide: skip probe if there are no devices on the port (v2) sl82c105: add printk() logging facility ide-tape: fix proc warning ide: add IDE_DFLAG_NIEN_QUIRK device flag ide: respect quirk_drives[] list on all controllers hpt366: enable all quirks for devices on quirk_drives[] list hpt366: sync quirk_drives[] list with pdc202xx_{new,old}.c ide: remove superfluous SELECT_MASK() call from do_rw_taskfile() ide: remove superfluous SELECT_MASK() call from ide_driveid_update() icside: remove superfluous ->maskproc method ide-tape: fix IDE_AFLAG_* atomic accesses ide-tape: change IDE_AFLAG_IGNORE_DSC non-atomically pdc202xx_old: kill resetproc() method pdc202xx_old: don't call pdc202xx_reset() on IRQ timeout pdc202xx_old: use ide_dma_test_irq() ide: preserve Host Protected Area by default (v2) ide-gd: implement block device ->set_capacity method (v2) ...
| * partitions: add ->set_capacity block device methodBartlomiej Zolnierkiewicz2009-06-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Add ->set_capacity block device method and use it in rescan_partitions() to attempt enabling native capacity of the device upon detecting the partition which exceeds device capacity. * Add GENHD_FL_NATIVE_CAPACITY flag to try limit attempts of enabling native capacity during partition scan. Together with the consecutive patch implementing ->set_capacity method in ide-gd device driver this allows automatic disabling of Host Protected Area (HPA) if any partitions overlapping HPA are detected. Cc: Robert Hancock <hancockrwd@gmail.com> Cc: Frans Pop <elendil@planet.nl> Cc: "Andries E. Brouwer" <Andries.Brouwer@cwi.nl> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Emphatically-Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* | block: Export I/O topology for block devices and partitionsMartin K. Petersen2009-05-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | block: include empty disks in /proc/diskstatsTejun Heo2009-04-22
|/ | | | | | | | | | | | | | | | /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>
* block: genhd.h cleanup patchPetros Koutoupis2009-03-24
| | | | | | | In include/linux/genhd.h: Line 335 has a comment that needs to be updated from: /* drivers/block/ll_rw_blk.c */ to /* block/blk-core.c */. Also as of kernel 2.6.16, the function definition for get_blkdev_list was removed from block/genhd.c but the function declaration is still present on line 339. This patch addresses both those fixes, by updating the comment and removing the declaration. Signed-off-by: Petros Koutoupis <pkoutoupis@hydrasystemsllc.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: genhd.h comment needs updatingPetros Koutoupis2009-03-24
| | | | | | | | | | | The include/linux/genhd.h file, on line 338-352 declares some function prototypes in which the comment on line 338 states that the definition of these prototypes are to be found at drivers/block/genhd.c. The problem is that genhd.c has been relocated to block/genhd.c. See attached patch to correct this minor cosmetic typo. Signed-off-by: Petros Koutoupis <pkoutoupis@hydrasystemsllc.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add one-hit cache for disk partition lookupJens Axboe2008-12-29
| | | | | | | | | | | | | | | | | 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>
* block: make add_partition() return pointer to hd_structTejun Heo2008-11-18
| | | | | | | | | | Make add_partition() return pointer to the new hd_struct on success and ERR_PTR() value on failure. This change will be used to fix md autodetection bug. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* proc: move /proc/diskstats boilerplate to block/genhd.cAlexey Dobriyan2008-10-23
| | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Jens Axboe <jens.axboe@oracle.com>
* proc: move rest of /proc/partitions code to block/genhd.cAlexey Dobriyan2008-10-23
| | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Jens Axboe <jens.axboe@oracle.com>
* block: allow disk to have extended device numberTejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | | Now that disk and partition handlings are mostly unified, it's easy to allow disk to have extended device number. This patch makes add_disk() use extended device number if disk->minors is zero. Both sd and ide-disk are updated to use this. * sd_format_disk_name() is implemented which can generically determine the drive name. This removes disk number restriction stemming from limited device names. * If sd index goes over SD_MAX_DISKS (which can be increased now BTW), sd simply doesn't initialize minors letting block layer choose extended device number. * If CONFIG_DEBUG_EXT_DEVT is set, both sd and ide-disk always set minors to 0 and use extended device numbers. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: replace @ext_minors with GENHD_FL_EXT_DEVTTejun Heo2008-10-09
| | | | | | | | | | | | | | | With previous changes, it's meaningless to limit the number of partitions. Replace @ext_minors with GENHD_FL_EXT_DEVT such that setting the flag allows the disk to have maximum number of allowed partitions (only limited by the number of entries in parsed_partitions as determined by MAX_PART constant). This kills not-too-pretty alloc_disk_ext[_node]() functions and makes @minors parameter to alloc_disk[_node]() unnecessary. The parameter is left alone to avoid disturbing the users. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: make partition array dynamicTejun Heo2008-10-09
| | | | | | | | | | | | disk->__part used to be statically allocated to the maximum possible number of partitions. This patch makes partition array allocation dynamic. The added overhead is minimal as only real change is one memory dereference changed to RCU one. This saves both a bit of memory and cpu cycles iterating through unoccupied slots and makes increasing partition limit easier. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move stats from disk to part0Tejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move stats related fields - stamp, in_flight, dkstats - from disk to part0 and unify stat handling such that... * part_stat_*() now updates part0 together if the specified partition is not part0. ie. part_stat_*() are now essentially all_stat_*(). * {disk|all}_stat_*() are gone. * part_round_stats() is updated similary. It handles part0 stats automatically and disk_round_stats() is killed. * part_{inc|dec}_in_fligh() is implemented which automatically updates part0 stats for parts other than part0. * disk_map_sector_rcu() is updated to return part0 if no part matches. Combined with the above changes, this makes NULL special case handling in callers unnecessary. * Separate stats show code paths for disk are collapsed into part stats show code paths. * Rename disk_stat_lock/unlock() to part_stat_lock/unlock() While at it, reposition stat handling macros a bit and add missing parentheses around macro parameters. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: kill GENHD_FL_FAIL and use part0->make_it_failTejun Heo2008-10-09
| | | | | | | | GENHD_FL_FAIL for disk is what make_it_fail is for parts. Kill it and use part0->make_it_fail. Sysfs node handling is unified too. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: always set bdev->bd_partTejun Heo2008-10-09
| | | | | | | | | Till now, bdev->bd_part is set only if the bdev was for parts other than part0. This patch makes bdev->bd_part always set so that code paths don't have to differenciate common handling. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move holder_dir from disk to part0Tejun Heo2008-10-09
| | | | | | | | | | | | | Move disk->holder_dir to part0->holder_dir. Kill now mostly superflous bdev_get_holder(). While at it, kill superflous kobject_get/put() around holder_dir, slave_dir and cmd_filter creation and collapse disk_sysfs_add_subdirs() into register_disk(). These serve no purpose but obfuscating the code. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move policy from disk to part0Tejun Heo2008-10-09
| | | | | | | Move disk->policy to part0->policy. Implement and use get_disk_ro(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: unify sysfs size node handlingTejun Heo2008-10-09
| | | | | | | | Now that capacity and __dev are moved to part0, part0 and others can share the same method. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move __dev from disk to part0Tejun Heo2008-10-09
| | | | | | | | | | | | | | | Move disk->__dev to part0->__dev. This simplifies bdget_disk() and lookup_devt() and allows common sysfs attributes to be unified. part_to_disk() is updated to handle part0 -> disk. Updated to include a fix from Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>, he writes: "part0 is a "special" partition and doesn't need to have capacity set - this fixes regression caused by "block: move __dev from disk to part0" commit." Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move capacity from disk to part0Tejun Heo2008-10-09
| | | | | | | | | Move disk->capacity to part0->nr_sects and convert all users who directly accessed the field to use {get|set}_capacity(). This is done early to allow the __dev field to be moved. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: introduce partition 0Tejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | genhd and partition code handled disk and partitions separately. All information about the whole disk was in struct genhd and partitions in struct hd_struct. However, the whole disk (part0) and other partitions have a lot in common and the data structures end up having good number of common fields and thus separate code paths doing the same thing. Also, the partition array was indexed by partno - 1 which gets pretty confusing at times. This patch introduces partition 0 and makes the partition array indexed by partno. Following patches will unify the handling of disk and parts piece-by-piece. This patch also implements disk_partitionable() which tests whether a disk is partitionable. With coming dynamic partition array change, the most common usage of disk_max_parts() will be testing whether a disk is partitionable and the number of max partitions will become much less important. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: implement and use {disk|part}_to_dev()Tejun Heo2008-10-09
| | | | | | | | | | | | Implement {disk|part}_to_dev() and use them to access generic device instead of directly dereferencing {disk|part}->dev. To make sure no user is left behind, rename generic devices fields to __dev. This is in preparation of unifying partition 0 handling with other partitions. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: implement extended dev numbersTejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | Implement extended device numbers. A block driver can tell block layer that it wants to use extended device numbers. After the usual minor space is used up, block layer automatically allocates devt's from EXT_BLOCK_MAJOR. Currently only one major number is allocated for this but as the allocation is strictly on-demand, ~1mil minor space under it should suffice unless the system actually has more than ~1mil partitions and if that ever happens adding more majors to the extended devt area is easy. Due to internal implementation issues, the first partition can't be allocated on the extended area. In other words, genhd->minors should at least be 1. This limitation will be lifted by later changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix diskstats accessTejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two variants of stat functions - ones prefixed with double underbars which don't care about preemption and ones without which disable preemption before manipulating per-cpu counters. It's unclear whether the underbarred ones assume that preemtion is disabled on entry as some callers don't do that. This patch unifies diskstats access by implementing disk_stat_lock() and disk_stat_unlock() which take care of both RCU (for partition access) and preemption (for per-cpu counter access). diskstats access should always be enclosed between the two functions. As such, there's no need for the versions which disables preemption. They're removed and double underbars ones are renamed to drop the underbars. As an extra argument is added, there's no danger of using the old version unconverted. disk_stat_lock() uses get_cpu() and returns the cpu index and all diskstat functions which access per-cpu counters now has @cpu argument to help RT. This change adds RCU or preemption operations at some places but also collapses several preemption ops into one at others. Overall, the performance difference should be negligible as all involved ops are very lightweight per-cpu ones. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix disk->part[] dereferencing raceTejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | disk->part[] is protected by its matching bdev's lock. However, non-critical accesses like collecting stats and printing out sysfs and proc information used to be performed without any locking. As partitions can come and go dynamically, partitions can go away underneath those non-critical accesses. As some of those accesses are writes, this theoretically can lead to silent corruption. This patch fixes the race by using RCU for the partition array and dev reference counter to hold partitions. * Rename disk->part[] to disk->__part[] to make sure no one outside genhd layer proper accesses it directly. * Use RCU for disk->__part[] dereferencing. * Implement disk_{get|put}_part() which can be used to get and put partitions from gendisk respectively. * Iterators are implemented to help iterate through all partitions safely. * Functions which require RCU readlock are marked with _rcu suffix. * Use disk_put_part() in __blkdev_put() instead of directly putting the contained kobject. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: don't depend on consecutive minor spaceTejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | * Implement disk_devt() and part_devt() and use them to directly access devt instead of computing it from ->major and ->first_minor. Note that all references to ->major and ->first_minor outside of block layer is used to determine devt of the disk (the part0) and as ->major and ->first_minor will continue to represent devt for the disk, converting these users aren't strictly necessary. However, convert them for consistency. * Implement disk_max_parts() to avoid directly deferencing genhd->minors. * Update bdget_disk() such that it doesn't assume consecutive minor space. * Move devt computation from register_disk() to add_disk() and make it the only one (all other usages use the initially determined value). These changes clean up the code and will help disk->part dereference fix and extended block device numbers. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: make variable and argument names more consistentTejun Heo2008-10-09
| | | | | | | | | | | | | | In hd_struct, @partno is used to denote partition number and a number of other places use @part to denote hd_struct. Functions use @part and @index instead. This causes confusion and makes it difficult to use consistent variable names for hd_struct. Always use @partno if a variable represents partition number. Also, print out functions use @f or @part for seq_file argument. Use @seqf uniformly instead. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: misc updatesTejun Heo2008-10-09
| | | | | | | | | | | | | | | | | This patch makes the following misc updates in preparation for disk->part dereference fix and extended block devt support. * implment part_to_disk() * fix comment about gendisk->part indexing * rename get_part() to disk_map_sector() * don't use n which is always zero while printing disk information in diskstats_show() Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-05 07:47:54 -0500