04 Jan, 2012

1 commit


10 Nov, 2011

1 commit

  • This reverts commit a72c5e5eb738033938ab30d6a634b74d1d060f10.

    The commit introduced alias for block devices which is intended to be
    used during logging although actual usage hasn't been committed yet.
    This approach adds very limited benefit (raw log might be easier to
    follow) which can be trivially implemented in userland but has a lot
    of problems.

    It is much worse than netif renames because it doesn't rename the
    actual device but just adds conveninence name which isn't used
    universally or enforced. Everything internal including device lookup
    and sysfs still uses the internal name and nothing prevents two
    devices from using conflicting alias - ie. sda can have sdb as its
    alias.

    This has been nacked by people working on device driver core, block
    layer and kernel-userland interface and shouldn't have been
    upstreamed. Revert it.

    http://thread.gmane.org/gmane.linux.kernel/1155104
    http://thread.gmane.org/gmane.linux.scsi/68632
    http://thread.gmane.org/gmane.linux.scsi/69776

    Signed-off-by: Tejun Heo
    Acked-by: Greg Kroah-Hartman
    Acked-by: Kay Sievers
    Cc: "James E.J. Bottomley"
    Cc: Nao Nishijima
    Cc: Alan Cox
    Cc: Al Viro
    Signed-off-by: Jens Axboe

    Tejun Heo
     

05 Nov, 2011

1 commit

  • * 'for-3.2/drivers' of git://git.kernel.dk/linux-block: (30 commits)
    virtio-blk: use ida to allocate disk index
    hpsa: add small delay when using PCI Power Management to reset for kump
    cciss: add small delay when using PCI Power Management to reset for kump
    xen/blkback: Fix two races in the handling of barrier requests.
    xen/blkback: Check for proper operation.
    xen/blkback: Fix the inhibition to map pages when discarding sector ranges.
    xen/blkback: Report VBD_WSECT (wr_sect) properly.
    xen/blkback: Support 'feature-barrier' aka old-style BARRIER requests.
    xen-blkfront: plug device number leak in xlblk_init() error path
    xen-blkfront: If no barrier or flush is supported, use invalid operation.
    xen-blkback: use kzalloc() in favor of kmalloc()+memset()
    xen-blkback: fixed indentation and comments
    xen-blkfront: fix a deadlock while handling discard response
    xen-blkfront: Handle discard requests.
    xen-blkback: Implement discard requests ('feature-discard')
    xen-blkfront: add BLKIF_OP_DISCARD and discard request struct
    drivers/block/loop.c: remove unnecessary bdev argument from loop_clr_fd()
    drivers/block/loop.c: emit uevent on auto release
    drivers/block/cpqarray.c: use pci_dev->revision
    loop: always allow userspace partitions and optionally support automatic scanning
    ...

    Fic up trivial header file includsion conflict in drivers/block/loop.c

    Linus Torvalds
     

29 Aug, 2011

1 commit

  • This patch allows the user to set an "alias" of the disk via sysfs interface.

    This patch only adds a new attribute "alias" in gendisk structure.
    To show the alias instead of the device name in kernel messages,
    we need to revise printk messages and use alias_name() in them.

    Example:
    (current) printk("disk name is %s\n", disk->disk_name);
    (new) printk("disk name is %s\n", alias_name(disk));

    Users can use alphabets, numbers, '-' and '_' in "alias" attribute. A disk can
    have an "alias" which length is up to 255 bytes. This attribute is write-once.

    Suggested-by: James Bottomley
    Suggested-by: Jon Masters
    Signed-off-by: Nao Nishijima
    Signed-off-by: James Bottomley

    Nao Nishijima
     

24 Aug, 2011

1 commit

  • There are cases where suppressing partition scan is useful - e.g. for
    lo devices and pseudo SATA devices which advertise to be a disk but
    get upset on partition scan (some port multiplier control devices show
    such behavior).

    This patch adds GENHD_FL_NO_PART_SCAN which suppresses partition scan
    regardless of the number of possible partitions. disk_partitionable()
    is renamed to disk_part_scan_enabled() as suppressing partition scan
    doesn't imply the device can't be partitioned using
    BLKPG_ADD/DEL_PARTITION calls from userland. show_partition() now
    directly tests disk_max_parts() to maintain backward-compatibility.

    -v2: Updated to make it clear that only partition scan is suppressed
    not partitioning itself as suggested by Kay Sievers.

    Signed-off-by: Tejun Heo
    Cc: Kay Sievers
    Signed-off-by: Jens Axboe

    Tejun Heo
     

01 Jul, 2011

1 commit

  • Currently, only open(2) is defined as the 'clearing' point. It has
    two roles - first, it's an acknowledgement from userland indicating
    that the event has been received and kernel can clear pending states
    and proceed to generate more events. Secondly, it's passed on to
    device drivers as a hint indicating that a synchronization point has
    been reached and it might want to take a deeper look at the device.

    The latter currently is only used by sr which uses two different
    mechanisms - GET_EVENT_MEDIA_STATUS_NOTIFICATION and TEST_UNIT_READY
    to discover events, where the former is lighter weight and safe to be
    used repeatedly but may not provide full coverage. Among other
    things, GET_EVENT can't detect media removal while TUR can.

    This patch makes close(2) - blkdev_put() - indicate clearing hint for
    MEDIA_CHANGE to drivers. disk_check_events() is renamed to
    disk_flush_events() and updated to take @mask for events to flush
    which is or'd to ev->clearing and will be passed to the driver on the
    next ->check_events() invocation.

    This change makes sr generate MEDIA_CHANGE when media is ejected from
    userland - e.g. with eject(1).

    Note: Given the current usage, it seems @clearing hint is needlessly
    complex. disk_clear_events() can simply clear all events and the hint
    can be boolean @flush.

    Signed-off-by: Tejun Heo
    Cc: Kay Sievers
    Signed-off-by: Jens Axboe

    Tejun Heo
     

30 May, 2011

1 commit

  • It was not a good idea to start dereferencing disk->queue from
    the fs sysfs strategy for displaying discard alignment. We ran
    into first a NULL pointer deref, and after fixing that we sometimes
    see unvalid disk->queue pointer values.

    Since discard is the only one of the bunch actually looking into
    the queue, just revert the change.

    This reverts commit 23ceb5b7719e9276d4fa72a3ecf94dd396755276.

    Conflicts:
    fs/partitions/check.c

    Jens Axboe
     

07 May, 2011

1 commit


22 Apr, 2011

1 commit

  • Disk event code automatically blocks events on excl write. This is
    primarily to avoid issuing polling commands while burning is in
    progress. This behavior doesn't fit other types of devices with
    removeable media where polling commands don't have adverse side
    effects and door locking usually doesn't exist.

    This patch introduces new genhd flag which controls the auto-blocking
    behavior and uses it to enable auto-blocking only on optical devices.

    Note for stable: 2.6.38 and later only

    Cc: stable@kernel.org
    Signed-off-by: Tejun Heo
    Reported-by: Kay Sievers
    Signed-off-by: Jens Axboe

    Tejun Heo
     

22 Mar, 2011

1 commit


13 Jan, 2011

1 commit


07 Jan, 2011

1 commit


05 Jan, 2011

1 commit

  • /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
    Signed-off-by: Yasuaki Ishimatsu
    Cc: stable@kernel.org
    Signed-off-by: Jens Axboe

    Jerome Marchand
     

17 Dec, 2010

3 commits

  • 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
    Cc: Kay Sievers
    Cc: Jan Kara
    Signed-off-by: Jens Axboe

    Tejun 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
    Signed-off-by: Jens Axboe

    Tejun Heo
     
  • There's no user of the facility. Kill it.

    Signed-off-by: Tejun Heo
    Signed-off-by: Jens Axboe

    Tejun Heo
     

25 Oct, 2010

1 commit


23 Oct, 2010

1 commit

  • * '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

    Linus Torvalds
     

19 Oct, 2010

1 commit

  • /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
    Cc: stable@kernel.org
    Signed-off-by: Jens Axboe

    Yasuaki Ishimatsu
     

15 Sep, 2010

1 commit

  • 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
    Signed-off-by: Jens Axboe

    Will Drewry
     

20 Aug, 2010

1 commit

  • This adds annotations for RCU operations in core kernel components

    Signed-off-by: Arnd Bergmann
    Signed-off-by: Paul E. McKenney
    Cc: Al Viro
    Cc: Jens Axboe
    Cc: Andrew Morton
    Reviewed-by: Josh Triplett

    Arnd Bergmann
     

16 Mar, 2010

1 commit

  • This flag is not used, so best discarded.

    Signed-off-by: NeilBrown
    --
    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

    NeilBrown
     

17 Feb, 2010

1 commit

  • 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
    Reviewed-by: Christoph Lameter
    Acked-by: Paul E. McKenney
    Cc: Jens Axboe
    Cc: linux-mm@kvack.org
    Cc: Rusty Russell
    Cc: Dipankar Sarma
    Cc: Peter Zijlstra
    Cc: Andrew Morton
    Cc: Eric Biederman

    Tejun Heo
     

11 Jan, 2010

1 commit


10 Nov, 2009

1 commit

  • 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
    Signed-off-by: Jens Axboe

    Martin K. Petersen
     

07 Oct, 2009

1 commit

  • 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 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

    --
    Signed-off-by: Jens Axboe

    Nikanth Karthikesan
     

05 Oct, 2009

1 commit

  • This reverts commit a9327cac440be4d8333bba975cbbf76045096275.

    Corrado Zoccolo 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
     

22 Sep, 2009

1 commit


20 Sep, 2009

1 commit

  • 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
    Signed-off-by: Greg Kroah-Hartman

    Kay Sievers
     

14 Sep, 2009

1 commit

  • 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
    Signed-off-by: Jens Axboe

    Nikanth Karthikesan
     

16 Jun, 2009

1 commit


13 Jun, 2009

1 commit

  • * '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)
    ...

    Linus Torvalds
     

07 Jun, 2009

1 commit

  • * 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
    Cc: Frans Pop
    Cc: "Andries E. Brouwer"
    Acked-by: Al Viro
    Emphatically-Acked-by: Alan Cox
    Signed-off-by: Bartlomiej Zolnierkiewicz

    Bartlomiej Zolnierkiewicz
     

23 May, 2009

1 commit

  • 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
    Signed-off-by: Jens Axboe

    Martin K. Petersen
     

22 Apr, 2009

1 commit

  • /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
    Reported-by: Daniel Collins
    Signed-off-by: Jens Axboe

    Tejun Heo
     

24 Mar, 2009

2 commits

  • 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
    Signed-off-by: Jens Axboe

    Petros Koutoupis
     
  • 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
    Signed-off-by: Jens Axboe

    Petros Koutoupis
     

29 Dec, 2008

1 commit

  • 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
     

18 Nov, 2008

1 commit


23 Oct, 2008

1 commit