Commit Graph

201 Commits

Author SHA1 Message Date
Randy Dunlap 710027a48e 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: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:03 +02:00
Tejun Heo ddef43a843 block: restore original behavior of /proc/partition when there's no partition
/proc/partitions didn't use to write out the header if there was no
partition.  However, recent commit 66c64afe changed the behavior.
This is nothing major but there's no reason to change user visible
behavior without a good rationale.  Restore the original behavior.

Note that 2.6.28 has clean up changes scheduled which will replace
this rather hacky implementation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-09-01 08:55:10 +02:00
FUJITA Tomonori bb23b431db remove blk_register_filter and blk_unregister_filter in gendisk
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 abf5439370 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: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reported-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-08-29 11:47:07 +02:00
Kay Sievers 5c0ef6d021 block: drop references taken by class_find_device()
Otherwise we leak references, which is not a good thing to do.


Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-21 10:15:38 -07:00
Kay Sievers 068281d302 block: fix partial read() of /proc/{partitions,diskstats}
The proc files get truncated if they do not fit into the buffer with
a single read(). We need to move the seq_file index from the callback
of class_find_device() to the caller of class_find_device(), to keep
its value across multiple invocations of the callback.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-21 10:15:38 -07:00
Greg Kroah-Hartman 27f3025191 block: make /proc/partitions and /proc/diskstats use class_find_device()
Use the proper class iterator function instead of mucking around in the
internals of the class structures.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:49 -07:00
Greg Kroah-Hartman 66c64afec1 block: move header for /proc/partitions to seq_start
The seq_start call is the better place for the header for the file, that
way we don't have to be mucking in the class structure to try to figure
out if this is the first partition or not.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:49 -07:00
Greg Kroah-Hartman 68c4d4a787 block: make proc files seq_start use the class_find_device()
Use the proper class iterator function instead of mucking around in the
internals of the class structures.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:49 -07:00
Randy Dunlap a6e2ba8877 block: make /proc/diskstats only build if CONFIG_PROC_FS is enabled
These functions are only needed if CONFIG_PROC_FS is enabled, so save
the space when it is not.

This also makes it easier for a patch later in this series to work
properly if CONFIG_PROC_FS is not enabled.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:49 -07:00
Greg Kroah-Hartman a142be856f block: make blk_lookup_devt use the class iterator function
Use the proper class iterator function instead of mucking around in the
internals of the class structures.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:48 -07:00
Greg Kroah-Hartman 5c6f35c5ec block: make printk_partition use the class iterator function
Use the proper class iterator function instead of mucking around in the
internals of the class structures.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:48 -07:00
Greg Kroah-Hartman 6ffeea77ff block: fix compiler warning in genhd.c
Warn if something really bad happens if we can't create this link.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:48 -07:00
Dan Williams e105b8bfc7 sysfs: add /sys/dev/{char,block} to lookup sysfs path by major:minor
Why?:
There are occasions where userspace would like to access sysfs
attributes for a device but it may not know how sysfs has named the
device or the path.  For example what is the sysfs path for
/dev/disk/by-id/ata-ST3160827AS_5MT004CK?  With this change a call to
stat(2) returns the major:minor then userspace can see that
/sys/dev/block/8:32 links to /sys/block/sdc.

What are the alternatives?:
1/ Add an ioctl to return the path: Doable, but sysfs is meant to reduce
   the need to proliferate ioctl interfaces into the kernel, so this
   seems counter productive.

2/ Use udev to create these symlinks: Also doable, but it adds a
   udev dependency to utilities that might be running in a limited
   environment like an initramfs.

3/ Do a full-tree search of sysfs.

[kay.sievers@vrfy.org: fix duplicate registrations]
[kay.sievers@vrfy.org: cleanup suggestions]

Cc: Neil Brown <neilb@suse.de>
Cc: Tejun Heo <htejun@gmail.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Reviewed-by: SL Baur <steve@xemacs.org>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Mark Lord <lkml@rtr.ca>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:40 -07:00
Adel Gadllah 0b07de85a7 allow userspace to modify scsi command filter on per device basis
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>
2008-07-03 13:21:14 +02:00
Kay Sievers 1c9ce52763 block: export "ro" attribute
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03 13:21:12 +02:00
Linus Torvalds d5791d13b1 Fix invalid access errors in blk_lookup_devt
Commit 30f2f0eb4b ("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: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: Neil Brown <neilb@suse.de>
Cc: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-09 10:06:24 -07:00
Kay Sievers 30f2f0eb4b block: do_mounts - accept root=<non-existant partition>
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>
2008-05-14 10:37:57 -07:00
Peter Zijlstra cf0ca9fe5d mm: bdi: export BDI attributes in sysfs
Provide a place in sysfs (/sys/class/bdi) for the backing_dev_info object.
This allows us to see and set the various BDI specific variables.

In particular this properly exposes the read-ahead window for all relevant
users and /sys/block/<block>/queue/read_ahead_kb should be deprecated.

With patient help from Kay Sievers and Greg KH

[mszeredi@suse.cz]

 - split off NFS and FUSE changes into separate patches
 - document new sysfs attributes under Documentation/ABI
 - do bdi_class_init as a core_initcall, otherwise the "default" BDI
   won't be initialized
 - remove bdi_init_fmt macro, it's not used very much

[akpm@linux-foundation.org: fix ia64 warning]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Greg KH <greg@kroah.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:49 -07:00
Roland McGrath ee27a558ae genhd must_check warning fix
Fixes:

	block/genhd.c:361: warning: ignoring return value of ‘class_register’, declared with attribute warn_unused_result

Signed-off-by: Roland McGrath <roland@redhat.com>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-12 12:34:37 -07:00
Adrian Bunk 1826eadfc4 block/genhd.c: cleanups
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>
2008-03-04 11:28:31 +01:00
Adrian Bunk ff88972c85 proper prototype for blk_dev_init()
This patch adds a proper prototye for blk_dev_init() in block/blk.h

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-03-04 11:28:29 +01:00
Jerome Marchand 28f39d553e Enhanced partition statistics: procfs
Reports enhanced partition statistics in /proc/diskstats.

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2008-02-08 12:42:00 +01:00
Jan Engelhardt 12f32bb317 block: constify function pointer tables
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-29 21:55:19 +01:00
Kay Sievers edfaa7c365 Driver core: convert block from raw kobjects to core devices
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>
2008-01-24 20:40:36 -08:00
Greg Kroah-Hartman 830d3cfb16 kset: convert block_subsys to use kset_create
Dynamically create the kset instead of declaring it statically.  We also
rename block_subsys to block_kset to catch all users of this symbol
with a build error instead of an easy-to-ignore build warning.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:23 -08:00
Greg Kroah-Hartman 3514faca19 kobject: remove struct kobj_type from struct kset
We don't need a "default" ktype for a kset.  We should set this
explicitly every time for each kset.  This change is needed so that we
can make ksets dynamic, and cleans up one of the odd, undocumented
assumption that the kset/kobject/ktype model has.

This patch is based on a lot of help from Kay Sievers.

Nasty bug in the block code was found by Dave Young
<hidave.darkstar@gmail.com>

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:10 -08:00
Jerome Marchand c7674030e5 block: Fix memory leak in alloc_disk_node()
Fix a memory leak in alloc_disk_node(). Don't forget to free 'dkstats' when the allocation of 'part' failed.

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-27 09:19:40 +01:00
Kay Sievers 7eff2e7a8b Driver core: change add_uevent_var to use a struct
This changes the uevent buffer functions to use a struct instead of a
long list of parameters. It does no longer require the caller to do the
proper buffer termination and size accounting, which is currently wrong
in some places. It fixes a known bug where parts of the uevent
environment are overwritten because of wrong index calculations.

Many thanks to Mathieu Desnoyers for finding bugs and improving the
error handling.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:01 -07:00
Akinobu Mita f4480240f7 unregister_blkdev(): return void
Put WARN_ON and fixed all callers of unregister_blkdev().  Now we can make
unregister_blkdev return void.

Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:03 -07:00
Akinobu Mita 294462a5c6 unregister_blkdev(): do WARN_ON on failure
When unregister_blkdev() has failed, something wrong happened.  This patch
adds WARN_ON to notify of such badness.

Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:03 -07:00
Christoph Lameter 94f6030ca7 Slab allocators: Replace explicit zeroing with __GFP_ZERO
kmalloc_node() and kmem_cache_alloc_node() were not available in a zeroing
variant in the past.  But with __GFP_ZERO it is possible now to do zeroing
while allocating.

Use __GFP_ZERO to remove the explicit clearing of memory via memset whereever
we can.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Kristen Carlson Accardi 8ce7ad7b2d genhd: send async notification on media change
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>
2007-05-23 20:14:12 -07:00
Kristen Carlson Accardi 86ce18d7b7 genhd: expose AN to user space
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>
2007-05-23 20:14:11 -07:00
Dave Gilbert dd2a345f8f Display all possible partitions when the root filesystem failed to mount
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>
2007-05-09 12:30:48 -07:00
Greg Kroah-Hartman 823bccfc40 remove "struct subsystem" as it is no longer needed
We need to work on cleaning up the relationship between kobjects, ksets and
ktypes.  The removal of 'struct subsystem' is the first step of this,
especially as it is not really needed at all.

Thanks to Kay for fixing the bugs in this patch.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 18:57:59 -07:00
Andrew Morton 2363cc0264 [PATCH] remove protection of LANANA-reserved majors
Revert all this.  It can cause device-mapper to receive a different major from
earlier kernels and it turns out that the Amanda backup program (via GNU tar,
apparently) checks major numbers on files when performing incremental backups.

Which is a bit broken of Amanda (or tar), but this feature isn't important
enough to justify the churn.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-04 21:12:47 -07:00
Andrew Morton b446b60e4e [PATCH] rework reserved major handling
Several people have reported failures in dynamic major device number handling
due to the recent changes in there to avoid handing out the local/experimental
majors.

Rolf reports that this is due to a gcc-4.1.0 bug.

The patch refactors that code a lot in an attempt to provoke the compiler into
behaving.

Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20 17:10:13 -08:00
Andrew Morton fdf892be32 [PATCH] register_blkdev(): don't hand out the LOCAL/EXPERIMENTAL majors
As pointed out in http://bugzilla.kernel.org/show_bug.cgi?id=7922, dynamic
blockdev major allocation can hand out majors which LANANA has defined as
being for local/experimental use.

Cc: Torben Mathiasen <device@lanana.org>
Cc: Greg KH <greg@kroah.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tomas Klas <tomas.klas@mepatek.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:27 -08:00
Akinobu Mita c17bb49517 [PATCH] fault-injection capability for disk IO
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>
2006-12-08 08:29:02 -08:00
Randy Dunlap 87a5726110 [PATCH] block: handle subsystem_register() init errors
Check and handle init errors.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:05 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Kay Sievers b9d9c82b4d [PATCH] Driver core: add generic "subsystem" link to all devices
Like the SUBSYTEM= key we find in the environment of the uevent, this
creates a generic "subsystem" link in sysfs for every device. Userspace
usually doesn't care at all if its a "class" or a "bus" device. This
provides an unified way to determine the subsytem of a device, regardless
of the way the driver core has created it.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-21 12:40:49 -07:00
Linus Torvalds 1a2acc9e92 Revert "[BLOCK] Fix oops on removal of SD/MMC card"
This reverts commit 56cf6504fc.

Both Erik Mouw and Andrew Vasquez independently pinpointed this commit
as causing problems, where the slab cache for a driver is never released
(most obviously causing problems when immediately re-loading that
driver, resulting in a "kmem_cache_create: duplicate cache <xyz>"
message, but it can also cause other trouble).

James Bottomley dug into it, and reports:

  "OK, here's the scoop.  The problem patch adds a get of driverfs_dev in
   add_disk(), but doesn't put it again until disk_release() (which occurs
   on final put_disk() of the gendisk).

   However, in SCSI, the driverfs_dev is the sdev_gendev.  That means
   there's a reference held on sdev_gendev  until final disk put.
   Unfortunately, we use the driver model driver_remove to trigger
   del_gendisk (which removes the gendisk from visibility and decrements
   the refcount), so we've introduced an unbreakable deadlock in the
   reference counting with this.

   I suggest simply reversing this patch at the moment.  If Russell and
   Jens can tell me what they're trying to do I'll see if there's another
   way to do it."

so hereby the patch gets reverted, waiting for a better fix.

Cc: Jens Axboe <axboe@suse.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Erik Mouw <erik@harddisk-recovery.com>
Cc: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-12 12:08:46 -07:00
Russell King 56cf6504fc [BLOCK] Fix oops on removal of SD/MMC card
The block layer keeps a reference (driverfs_dev) to the struct
device associated with the block device, and uses it internally
for generating uevents in block_uevent.

Block device uevents include umounting the partition, which can
occur after the backing device has been removed.

Unfortunately, this reference is not counted.  This means that
if the struct device is removed from the device tree, the block
layers reference will become stale.

Guard against this by holding a reference to the struct device
in add_disk(), and only drop the reference when we're releasing
the gendisk kobject - in other words when we can be sure that no
further uevents will be generated for this block device.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Jens Axboe <axboe@suse.de>
2006-05-05 17:57:52 +01:00
Joe Korty 68eef3b479 [PATCH] Simplify proc/devices and fix early termination regression
Make baby-simple the code for /proc/devices.  Based on the proven design
for /proc/interrupts.

This also fixes the early-termination regression 2.6.16 introduced, as
demonstrated by:

    # dd if=/proc/devices bs=1
    Character devices:
      1 mem
    27+0 records in
    27+0 records out

This should also work (but is untested) when /proc/devices >4096 bytes,
which I believe is what the original 2.6.16 rewrite fixed.

[akpm@osdl.org: cleanups, simplifications]
Signed-off-by: Joe Korty <joe.korty@ccur.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:53 -08:00
Ben Woodard 837c787877 [BLOCK] increase size of disk stat counters
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>
2006-03-27 09:29:02 +02:00
Jes Sorensen 58383af629 [PATCH] kobj_map semaphore to mutex conversion
Convert the kobj_map code to use a mutex instead of a semaphore.  It
converts the single two users as well, genhd.c and char_dev.c.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-20 13:42:58 -08:00
Neil Horman 7170be5f58 [PATCH] convert /proc/devices to use seq_file interface
A Christoph suggested that the /proc/devices file be converted to use the
seq_file interface.  This patch does that.

I've obxerved one or two installation that had sufficiently large sans that
they overran the 4k limit on /proc/devices.

Signed-off-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 18:25:19 -08:00
Kay Sievers 312c004d36 [PATCH] driver core: replace "hotplug" by "uevent"
Leave the overloaded "hotplug" word to susbsystems which are handling
real devices. The driver core does not "plug" anything, it just exports
the state to userspace and generates events.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-04 16:18:08 -08:00
Jens Axboe 47a004103d [BLOCK] Document the READ/WRITE splitup of the disk stats
Use the symbolic name where appropriate and add a comment to the
disk_stats structure.

Signed-off-by: Jens Axboe <axboe@suse.de>
2005-11-12 10:55:21 +01:00
Jens Axboe 3a65dfe8c0 [BLOCK] Move all core block layer code to new block/ directory
drivers/block/ is right now a mix of core and driver parts. Lets move
the core parts to a new top level directory. Al will move the fs/
related block parts to block/ next.

Signed-off-by: Jens Axboe <axboe@suse.de>
2005-11-04 08:43:35 +01:00