1. 09 Oct, 2008 19 commits
    • Tejun Heo's avatar
      block: move stats from disk to part0 · 074a7aca
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      074a7aca
    • Tejun Heo's avatar
      block: kill GENHD_FL_FAIL and use part0->make_it_fail · eddb2e26
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      eddb2e26
    • Tejun Heo's avatar
      block: move policy from disk to part0 · b7db9956
      Tejun Heo authored
      Move disk->policy to part0->policy.  Implement and use get_disk_ro().
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      b7db9956
    • Tejun Heo's avatar
      block: unify sysfs size node handling · e5610521
      Tejun Heo authored
      Now that capacity and __dev are moved to part0, part0 and others can
      share the same method.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      e5610521
    • Tejun Heo's avatar
      block: move __dev from disk to part0 · 548b10eb
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      548b10eb
    • Tejun Heo's avatar
      block: introduce partition 0 · b5d0b9df
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      b5d0b9df
    • Tejun Heo's avatar
      block: implement and use {disk|part}_to_dev() · ed9e1982
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      ed9e1982
    • Tejun Heo's avatar
      block: implement CONFIG_DEBUG_BLOCK_EXT_DEVT · 870d6656
      Tejun Heo authored
      Extended devt introduces non-contiguos device numbers.  This patch
      implements a debug option which forces most devt allocations to be
      from the extended area and spreads them out.  This is enabled by
      default if DEBUG_KERNEL is set and achieves...
      
      1. Detects code paths in kernel or userland which expect predetermined
         consecutive device numbers.
      
      2. When something goes wrong, avoid corruption as adding to the minor
         of earlier partition won't lead to the wrong but valid device.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      870d6656
    • Tejun Heo's avatar
      block: adjust formatting for large minors and add ext_range sysfs attr · 1f014290
      Tejun Heo authored
      With extended minors and the soon-to-follow debug feature, large minor
      numbers for block devices will be common.  This patch does the
      followings to make printouts pretty.
      
      * Adapt print formats such that large minors don't break the
        formatting.
      
      * For extended MAJ:MIN, %02x%02x for MAJ:MIN used in
        printk_all_partitions() doesn't cut it anymore.  Update it such that
        %03x:%05x is used if either MAJ or MIN doesn't fit in %02x.
      
      * Implement ext_range sysfs attribute which shows total minors the
        device can use including both conventional minor space and the
        extended one.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      1f014290
    • Tejun Heo's avatar
      block: implement extended dev numbers · bcce3de1
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      bcce3de1
    • Tejun Heo's avatar
      block: fix diskstats access · c9959059
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      c9959059
    • Tejun Heo's avatar
      block: fix disk->part[] dereferencing race · e71bf0d0
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      e71bf0d0
    • Tejun Heo's avatar
      block: don't depend on consecutive minor space · f331c029
      Tejun Heo authored
      * 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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      f331c029
    • Tejun Heo's avatar
      block: make variable and argument names more consistent · cf771cb5
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      cf771cb5
    • Tejun Heo's avatar
      block: misc updates · 310a2c10
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      310a2c10
    • Tejun Heo's avatar
      block: use class_dev_iterator instead of class_for_each_device() · def4e38d
      Tejun Heo authored
      Recent block_class iteration updates 5c6f35c5..27f30251 converted all
      class device iteration to class_for_each_device() and
      class_find_device(), which are correct but pain in the ass to use.
      This pach converts them to newly introduced class_dev_iterator so that
      they can use more natural control structures instead of separate
      callbacks and struct to pass parameters to them.
      
      This results in smaller and easier code.
      
      This patch also restores the original behavior of not printing header
      in /proc/partitions if there's no partition to print.  This is trivial
      but still user-visible behavior.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      def4e38d
    • Tejun Heo's avatar
      block: don't grab block_class_lock unnecessarily · 2ac3cee5
      Tejun Heo authored
      block_class_lock protects major_names array and bdev_map and doesn't
      have anything to do with block class devices.  Don't grab them while
      iterating over block class devices.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      2ac3cee5
    • Tejun Heo's avatar
      block: fix partition info printouts · ac65ece4
      Tejun Heo authored
      Recent block_class iteration updates 5c6f35c5..27f30251 broke partition
      info printouts.
      
      * printk_all_partitions(): Partition print out stops when it meets a
        partition hole.  Partition printing inner loop should continue
        instead of exiting on empty partition slot.
      
      * /proc/partitions and /proc/diskstats: If all information can't be
        read in single read(), the information is truncated.  This is
        because find_start() doesn't actually update the counter containing
        the initial seek.  It runs to the end and ends up always reporting
        EOF on the second read.
      
      This patch fixes both problems.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      ac65ece4
    • Randy Dunlap's avatar
      Add some block/ source files to the kernel-api docbook. Fix kernel-doc... · 710027a4
      Randy Dunlap authored
      Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC.
      Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      710027a4
  2. 01 Sep, 2008 1 commit
  3. 29 Aug, 2008 1 commit
    • FUJITA Tomonori's avatar
      remove blk_register_filter and blk_unregister_filter in gendisk · bb23b431
      FUJITA Tomonori authored
      This patch remove blk_register_filter and blk_unregister_filter in
      gendisk, and adds them to sd.c, sr.c. and ide-cd.c
      
      The commit abf54393 moved cmdfilter
      from gendisk to request_queue. It turned out that in some subsystems
      multiple gendisks share a single request_queue. So we get:
      
      Using physmap partition information
      Creating 3 MTD partitions on "physmap-flash":
      0x00000000-0x01c00000 : "User FS"
      0x01c00000-0x01c40000 : "booter"
      kobject (8511c410): tried to init an initialized object, something is seriously wrong.
      Call Trace:
      [<8036644c>] dump_stack+0x8/0x34
      [<8021f050>] kobject_init+0x50/0xcc
      [<8021fa18>] kobject_init_and_add+0x24/0x58
      [<8021d20c>] blk_register_filter+0x4c/0x64
      [<8021c194>] add_disk+0x78/0xe0
      [<8027d14c>] add_mtd_blktrans_dev+0x254/0x278
      [<8027c8f0>] blktrans_notify_add+0x40/0x78
      [<80279c00>] add_mtd_device+0xd0/0x150
      [<8027b090>] add_mtd_partitions+0x568/0x5d8
      [<80285458>] physmap_flash_probe+0x2ac/0x334
      [<802644f8>] driver_probe_device+0x12c/0x244
      [<8026465c>] __driver_attach+0x4c/0x84
      [<80263c64>] bus_for_each_dev+0x58/0xac
      [<802633ec>] bus_add_driver+0xc4/0x24c
      [<802648e0>] driver_register+0xcc/0x184
      [<80100460>] _stext+0x60/0x1bc
      
      In the long term, we need to fix such subsystems but we need a quick
      fix now. This patch add the command filter support to only sd and sr
      though it might be useful for other SG_IO users (such as cciss).
      Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
      Reported-by: default avatarManuel Lauss <mano@roarinelk.homelinux.net>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      bb23b431
  4. 21 Aug, 2008 2 commits
  5. 22 Jul, 2008 8 commits
  6. 03 Jul, 2008 2 commits
  7. 09 Jun, 2008 1 commit
    • Linus Torvalds's avatar
      Fix invalid access errors in blk_lookup_devt · d5791d13
      Linus Torvalds authored
      Commit 30f2f0eb ("block: do_mounts -
      accept root=<non-existant partition>") extended blk_lookup_devt() to be
      able to look up partitions that had not yet been registered, but in the
      process made the assumption that the '&block_class.devices' list only
      contains disk devices and that you can do 'dev_to_disk(dev)' on them.
      
      That isn't actually true.  The block_class device list also contains the
      partitions we've discovered so far, and you can't just do a
      'dev_to_disk()' on those.
      
      So make sure to only work on devices that block/genhd.c has registered
      itself, something we can test by checking the 'dev->type' member.  This
      makes the loop in blk_lookup_devt() match the other such loops in this
      file.
      
      [ We may want to do an alternate version that knows to handle _either_
        whole-disk devices or partitions, but for now this is the minimal fix
        for a series of crashes reported by Mariusz Kozlowski in
      
      	http://lkml.org/lkml/2008/5/25/25
      
        and Ingo in
      
      	http://lkml.org/lkml/2008/6/9/39 ]
      Reported-by: default avatarMariusz Kozlowski <m.kozlowski@tuxland.pl>
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Cc: Neil Brown <neilb@suse.de>
      Cc: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br>
      Acked-by: Kay Sievers's avatarKay Sievers <kay.sievers@vrfy.org>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d5791d13
  8. 14 May, 2008 1 commit
  9. 30 Apr, 2008 1 commit
  10. 12 Mar, 2008 1 commit
  11. 04 Mar, 2008 2 commits
  12. 08 Feb, 2008 1 commit