Pull core block IO bits from Jens Axboe:
"The most complicated part if this is the request allocation rework by
Tejun, which has been queued up for a long time and has been in
for-next ditto as well.
There are a few commits from yesterday and today, mostly trivial and
obvious fixes. So I'm pretty confident that it is sound. It's also
smaller than usual."
* 'for-3.6/core' of git://git.kernel.dk/linux-block:
block: remove dead func declaration
block: add partition resize function to blkpg ioctl
block: uninitialized ioc->nr_tasks triggers WARN_ON
block: do not artificially constrain max_sectors for stacking drivers
blkcg: implement per-blkg request allocation
block: prepare for multiple request_lists
block: add q->nr_rqs[] and move q->rq.elvpriv to q->nr_rqs_elvpriv
blkcg: inline bio_blkcg() and friends
block: allocate io_context upfront
block: refactor get_request[_wait]()
block: drop custom queue draining used by scsi_transport_{iscsi|fc}
mempool: add @gfp_mask to mempool_create_node()
blkcg: make root blkcg allocation use %GFP_KERNEL
blkcg: __blkg_lookup_create() doesn't need radix preload
Add a new operation code (BLKPG_RESIZE_PARTITION) to the BLKPG ioctl that
allows altering the size of an existing partition, even if it is currently
in use.
This patch converts hd_struct->nr_sects into sequence counter because
One might extend a partition while IO is happening to it and update of
nr_sects can be non-atomic on 32bit machines with 64bit sector_t. This
can lead to issues like reading inconsistent size of a partition. Sequence
counter have been used so that readers don't have to take bdev mutex lock
as we call sector_in_part() very frequently.
Now all the access to hd_struct->nr_sects should happen using sequence
counter read/update helper functions part_nr_sects_read/part_nr_sects_write.
There is one exception though, set_capacity()/get_capacity(). I think
theoritically race should exist there too but this patch does not
modify set_capacity()/get_capacity() due to sheer number of call sites
and I am afraid that change might break something. I have left that as a
TODO item. We can handle it later if need be. This patch does not introduce
any new races as such w.r.t set_capacity()/get_capacity().
v2: Add CONFIG_LBDAF test to UP preempt case as suggested by Phillip.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Phillip Susi <psusi@ubuntu.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This function is not really specific to the genhd layer and there are various
re-implementations or open-coded variants of it all throughout the kernel. To
avoid further duplications move the function to a more generic place.
While moving also convert it from a macro to a inline function.
Potential users of this function can be detected and converted using the
following coccinelle patch:
// <smpl>
@@
expression k;
@@
-container_of(k, struct device, kobj)
+kobj_to_dev(kobj)
// </smpl>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6d1d8050b4 "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, b5af921ec0 "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>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since 2.6.39 (1196f8b), when a driver returns -ENOMEDIUM for open(),
__blkdev_get() calls rescan_partitions() to remove
in-kernel partition structures and raise KOBJ_CHANGE uevent.
However it ends up calling driver's revalidate_disk without open
and could cause oops.
In the case of SCSI:
process A process B
----------------------------------------------
sys_open
__blkdev_get
sd_open
returns -ENOMEDIUM
scsi_remove_device
<scsi_device torn down>
rescan_partitions
sd_revalidate_disk
<oops>
Oopses are reported here:
http://marc.info/?l=linux-scsi&m=132388619710052
This patch separates the partition invalidation from rescan_partitions()
and use it for -ENOMEDIUM case.
Reported-by: Huajun Li <huajun.li.lee@gmail.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
both callers of device_get_devnode() are only interested in lower 16bits
and nobody tries to return anything wider than 16bit anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This reverts commit a72c5e5eb7.
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/1155104http://thread.gmane.org/gmane.linux.scsi/68632http://thread.gmane.org/gmane.linux.scsi/69776
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Nao Nishijima <nao.nishijima.xt@hitachi.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
* '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
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 <James.Bottomley@HansenPartnership.com>
Suggested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Nao Nishijima <nao.nishijima.xt@hitachi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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 <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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 <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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 23ceb5b771.
Conflicts:
fs/partitions/check.c
Currently, hd_struct.discard_alignment is only used when we
show /sys/block/sdx/sdx/discard_alignment. So remove it and
calculate when it is asked to show.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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 <tj@kernel.org>
Reported-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
After the stack plugging introduction, these are called lockless.
Ensure that the counters are updated atomically.
Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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>
/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>
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>
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>
This reverts commit 7681bfeecc.
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>
* '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
/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>
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: 2bfc96a127
(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>
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>
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>
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>
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>
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>
Commit a9327cac44 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 0f78ab9899
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>
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>
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>
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>
* '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)
...
* 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>
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>
/proc/diskstats used to show stats for all disks whether they're
zero-sized or not and their non-zero partitions. Commit
074a7aca7a 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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
* 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>
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>
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>
cmd_filter works only for the block layer SG_IO with SCSI block
devices. It breaks scsi/sg.c, bsg, and the block layer SG_IO with SCSI
character devices (such as st). We hit a kernel crash with them.
The problem is that cmd_filter code accesses to gendisk (having struct
blk_scsi_cmd_filter) via inode->i_bdev->bd_disk. It works for only
SCSI block device files. With character device files, inode->i_bdev
leads you to struct cdev. inode->i_bdev->bd_disk->blk_scsi_cmd_filter
isn't safe.
SCSI ULDs don't expose gendisk; they keep it private. bsg needs to be
independent on any protocols. We shouldn't change ULDs to expose their
gendisk.
This patch moves struct blk_scsi_cmd_filter from gendisk to
request_queue, a common object, which eveyone can access to.
The user interface doesn't change; users can change the filters via
/sys/block/. gendisk has a pointer to request_queue so the cmd_filter
code accesses to struct blk_scsi_cmd_filter.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch exports the per-gendisk command filter to user space through
sysfs, so it can be changed by the system administrator.
All users of the old cmd filter have been converted to use the new one.
Original patch from Peter Jones.
Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Some block devices support verifying the integrity of requests by way
of checksums or other protection information that is submitted along
with the I/O.
This patch implements support for generating and verifying integrity
metadata, as well as correctly merging, splitting and cloning bios and
requests that have this extra information attached.
See Documentation/block/data-integrity.txt for more information.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Some devices, like md, may create partitions only at first access,
so allow root= to be set to a valid non-existant partition of an
existing disk. This applies only to non-initramfs root mounting.
This fixes a regression from 2.6.24 which did allow this to happen and
broke some users machines :(
Acked-by: Neil Brown <neilb@suse.de>
Tested-by: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br>
Cc: stable <stable@kernel.org>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
get_part() is fairly expensive, as it O(N) loops over partitions
to find the right one. In lots of normal IO paths we end up looking
up the partition twice, to make matters even worse. Change the
stat add code to accept a passed in partition instead.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It was all wrapped in '#ifdef CONFIG_BLOCK' anyway, so userspace was
getting nothing useful out of it. And the special #ifndef __KERNEL__
version of 'struct partition' makes me inclined to promote an attitude
of violence...
Stick some comments on some of the #endifs too, while we're at it.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds proper externs for two structs in include/linux/genhd.h
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch contains the following cleanups:
- make the needlessly global struct disk_type static
- #if 0 the unused genhd_media_change_notify()
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch contain the core infrastructure of enhanced partition
statistics. It adds to struct hd_struct the same stats data as struct
gendisk and define basics function to manipulate them.
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This moves the block devices to /sys/class/block. It will create a
flat list of all block devices, with the disks and partitions in one
directory. For compatibility /sys/block is created and contains symlinks
to the disks.
/sys/class/block
|-- sda -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda
|-- sda1 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda1
|-- sda10 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda10
|-- sda5 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda5
|-- sda6 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda6
|-- sda7 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda7
|-- sda8 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda8
|-- sda9 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda9
`-- sr0 -> ../../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0
/sys/block/
|-- sda -> ../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda
`-- sr0 -> ../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Correct the Solaris x86 number of partitions (slices) is a way that is
backward compatible with the earlier size.
This works without a new VTOC structure definition as the timestamp
and v_asciilabel fields in the VTOC are not used by the kernel yet.
Signed-off-by: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Send an uevent to user space to indicate that a media change event has
occurred.
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow user space to determine if a disk supports Asynchronous Notification of
media changes. This is done by adding a new sysfs file "capability_flags",
which is documented in (insert file name). This sysfs file will export all
disk capabilities flags to user space. We also define a new flag to define
the media change notification capability.
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Display all possible partitions when the root filesystem is not mounted.
This helps to track spell'o's and missing drivers.
Updated to work with newer kernels.
Example output:
VFS: Cannot open root device "foobar" or unknown-block(0,0)
Please append a correct "root=" boot option; here are the available partitions:
0800 8388608 sda driver: sd
0801 192748 sda1
0802 8193150 sda2
0810 4194304 sdb driver: sd
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[akpm@linux-foundation.org: cleanups, fix printk warnings]
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Cc: Dave Gilbert <linux@treblig.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The patch to identify AIX disks and ignore them has caused at least one
machine to fail to find the root partition on 2.6.19. The patch is:
http://lkml.org/lkml/2006/7/31/117
The problem is some disk formatters do not blow away the first 4 bytes
of the disk. If the disk we are installing to used to have AIX on it,
then the first 4 bytes will still have IBMA in EBCDIC.
The install in question was debian etch. Im not sure what the best fix
is, perhaps the AIX detection code could check more than the first 4
bytes.
The whole partition info for primary partitions is in this block:
dd if=/dev/sdb count=$(( 4 * 16 )) bs=1 skip=$(( 0x1be ))
All other data do not matter, beside the 0x55aa marker at the end of the
first block.
Signed-off-by: Olaf Hering <olh@suse.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some partitioning systems create special partitions that
span the entire disk. One example are Sun partitions, and
this whole-disk partition exists to tell the firmware the
extent of the entire device so it can load the boot block
and do other things.
Such partitions should not be treated as normal partitions,
because all the other partitions overlap this whole-disk one.
So we'd see multiple instances of the same UUID etc. which
we do not want. udev and friends can thus search for this
'whole_disk' attribute and use it to decide to ignore the
partition.
Signed-off-by: Fabio Massimo Di Nitto <fabbione@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch provides fault-injection capability for disk IO.
Boot option:
fail_make_request=<probability>,<interval>,<space>,<times>
<interval> -- specifies the interval of failures.
<probability> -- specifies how often it should fail in percent.
<space> -- specifies the size of free space where disk IO can be issued
safely in bytes.
<times> -- specifies how many times failures may happen at most.
Debugfs:
/debug/fail_make_request/interval
/debug/fail_make_request/probability
/debug/fail_make_request/specifies
/debug/fail_make_request/times
Example:
fail_make_request=10,100,0,-1
echo 1 > /sys/blocks/hda/hda1/make-it-fail
generic_make_request() on /dev/hda1 fails once per 10 times.
Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[BLOCK] delay all uevents until partition table is scanned
Here we delay the annoucement of all block device events until the
disk's partition table is scanned and all partition devices are already
created and sysfs is populated.
We have a bunch of old bugs for removable storage handling where we
probe successfully for a filesystem on the raw disk, but at the
same time the kernel recognizes a partition table and creates partition
devices.
Currently there is no sane way to tell if partitions will show up or not
at the time the disk device is announced to userspace. With the delayed
events we can simply skip any probe for a filesystem on the raw disk when
we find already present partitions.
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'for-linus' of git://brick.kernel.dk/data/git/linux-2.6-block:
[PATCH] Don't make debugfs depend on DEBUG_KERNEL
[PATCH] Fix blktrace compile with sysfs not defined
[PATCH] unused label in drivers/block/cciss.
[BLOCK] increase size of disk stat counters
[PATCH] blk_execute_rq_nowait-speedup
[PATCH] ide-cd: quiet down GPCMD_READ_CDVD_CAPACITY failure
[BLOCK] ll_rw_blk: kmalloc -> kzalloc conversion
[PATCH] kzalloc() conversion in drivers/block
[PATCH] update max_sectors documentation
Remove all the CONFIG_SYSFS stuff. That's supposed to all be implemented up
in header files.
Yes, the CONFIG_SYSFS=n data structures will be a little larger than
necessary, but that's a tradeoff we can decide to make.
Cc: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Creating "slaves" and "holders" directories in /sys/block/<disk> and
creating "holders" directory under /sys/block/<disk>/<partition>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The kernel's representation of the disk statistics uses the type unsigned
which is 32b on both 32b and 64b platforms. Unfortunately, most system
tools that work with these numbers that are exported in /proc/diskstats
including iostat read these numbers into unsigned longs. This works fine
on 32b platforms and when the number of IO transactions are small on 64b
platforms. However, when the numbers wrap on 64b platforms & you read the
numbers into unsigned longs, and compare the numbers to previous readings,
then you get an unsigned representation of a negative number. This looks
like a very large 64b number & gives you bizarre readouts in iostat:
ilc4: Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
ilc4: sda 5.50 0.00 143.96 0.00 307496983987862656.00 0.00 153748491993931328.00 0.00 2136028725038430.00 7.94 55.12 5.59 80.42
Though fixing iostat in user space is possible, and a quick survey
indicates that several other similar tools also use unsigned longs when
processing /proc/diskstats. Therefore, it seems like a better approach
would be to extend the length of the disk_stats structure on 64b
architectures to 64b. The following patch does that. It should not affect
the operation on 32b platforms.
Signed-off-by: Ben Woodard <woodard@redhat.com>
Cc: Rick Lindsley <ricklind@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jens Axboe <axboe@suse.de>
When we stop allocating percpu memory for not-possible CPUs we must not touch
the percpu data for not-possible CPUs at all. The correct way of doing this
is to test cpu_possible() or to use for_each_cpu().
This patch is a kernel-wide sweep of all instances of NR_CPUS. I found very
few instances of this bug, if any. But the patch converts lots of open-coded
test to use the preferred helper macros.
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Christian Zankel <chris@zankel.net>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Instead of having ->read_sectors and ->write_sectors, combine the two
into ->sectors[2] and similar for the other fields. This saves a branch
several places in the io path, since we don't have to care for what the
actual io direction is. On my x86-64 box, that's 200 bytes less text in
just the core (not counting the various drivers).
Signed-off-by: Jens Axboe <axboe@suse.de>
Linus Torvalds