linux-stable.git/drivers/block, branch linux-2.6.38.y

brd: handle on-demand devices correctly

2011-06-03T01:34:45+00:00

commit af46566885a373b0a526932484cd8fef8de7b598 upstream.

When finding or allocating a ram disk device, brd_probe() did not take
partition numbers into account so that it can result to a different
device. Consider following example (I set CONFIG_BLK_DEV_RAM_COUNT=4
for simplicity) :

$ sudo modprobe brd max_part=15
$ ls -l /dev/ram*
brw-rw---- 1 root disk 1,  0 2011-05-25 15:41 /dev/ram0
brw-rw---- 1 root disk 1, 16 2011-05-25 15:41 /dev/ram1
brw-rw---- 1 root disk 1, 32 2011-05-25 15:41 /dev/ram2
brw-rw---- 1 root disk 1, 48 2011-05-25 15:41 /dev/ram3
$ sudo mknod /dev/ram4 b 1 64
$ sudo dd if=/dev/zero of=/dev/ram4 bs=4k count=256
256+0 records in
256+0 records out
1048576 bytes (1.0 MB) copied, 0.00215578 s, 486 MB/s
namhyung@leonhard:linux$ ls -l /dev/ram*
brw-rw---- 1 root disk 1,    0 2011-05-25 15:41 /dev/ram0
brw-rw---- 1 root disk 1,   16 2011-05-25 15:41 /dev/ram1
brw-rw---- 1 root disk 1,   32 2011-05-25 15:41 /dev/ram2
brw-rw---- 1 root disk 1,   48 2011-05-25 15:41 /dev/ram3
brw-r--r-- 1 root root 1,   64 2011-05-25 15:45 /dev/ram4
brw-rw---- 1 root disk 1, 1024 2011-05-25 15:44 /dev/ram64

After this patch, /dev/ram4 - instead of /dev/ram64 - was
accessed correctly.

In addition, 'range' passed to blk_register_region() should
include all range of dev_t that RAMDISK_MAJOR can address.
It does not need to be limited by partition numbers unless
'rd_nr' param was specified.

Signed-off-by: Namhyung Kim 
Cc: Laurent Vivier 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

brd: limit 'max_part' module param to DISK_MAX_PARTS

2011-06-03T01:34:44+00:00

commit 315980c8688c4b06713c1a5fe9d64cdf8ab57a72 upstream.

The 'max_part' parameter controls the number of maximum partition
a brd device can have. However if a user specifies very large
value it would exceed the limitation of device minor number and
can cause a kernel panic (or, at least, produce invalid device
nodes in some cases).

On my desktop system, following command kills the kernel. On qemu,
it triggers similar oops but the kernel was alive:

$ sudo modprobe brd max_part=100000
 BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
 IP: [] sysfs_create_dir+0x2d/0xae
 PGD 7af1067 PUD 7b19067 PMD 0
 Oops: 0000 [#1] SMP
 last sysfs file:
 CPU 0
 Modules linked in: brd(+)

 Pid: 44, comm: insmod Tainted: G        W   2.6.39-qemu+ #158 Bochs Bochs
 RIP: 0010:[]  [] sysfs_create_dir+0x2d/0xae
 RSP: 0018:ffff880007b15d78  EFLAGS: 00000286
 RAX: ffff880007b05478 RBX: ffff880007a52760 RCX: ffff880007b15dc8
 RDX: ffff880007a4f900 RSI: ffff880007b15e48 RDI: ffff880007a52760
 RBP: ffff880007b15da8 R08: 0000000000000002 R09: 0000000000000000
 R10: ffff880007b15e48 R11: ffff880007b05478 R12: 0000000000000000
 R13: ffff880007b05478 R14: 0000000000400920 R15: 0000000000000063
 FS:  0000000002160880(0063) GS:ffff880007c00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000058 CR3: 0000000007b1c000 CR4: 00000000000006b0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 0000000000000000 DR7: 0000000000000000
 Process insmod (pid: 44, threadinfo ffff880007b14000, task ffff880007acb980)
 Stack:
  ffff880007b15dc8 ffff880007b05478 ffff880007b15da8 00000000fffffffe
  ffff880007a52760 ffff880007b05478 ffff880007b15de8 ffffffff81143c0a
  0000000000400920 ffff880007a52760 ffff880007b05478 0000000000000000
 Call Trace:
  [] kobject_add_internal+0xdf/0x1a0
  [] kobject_add_varg+0x41/0x50
  [] kobject_add+0x64/0x66
  [] blk_register_queue+0x5f/0xb8
  [] add_disk+0xdf/0x289
  [] brd_init+0xdf/0x1aa [brd]
  [] ? 0xffffffffa0003fff
  [] ? 0xffffffffa0003fff
  [] do_one_initcall+0x7a/0x12e
  [] sys_init_module+0x9c/0x1dc
  [] system_call_fastpath+0x16/0x1b
 Code: 89 e5 41 55 41 54 53 48 89 fb 48 83 ec 18 48 85 ff 75 04 0f 0b eb fe 48 8b 47 18 49 c7 c4 70 1e 4d 81 48 85 c0 74 04 4c 8b 60 30
  8b 44 24 58 45 31 ed 0f b6 c4 85 c0 74 0d 48 8b 43 28 48 89
 RIP  [] sysfs_create_dir+0x2d/0xae
  RSP 
 CR2: 0000000000000058
 ---[ end trace aebb1175ce1f6739 ]---

Signed-off-by: Namhyung Kim 
Cc: Laurent Vivier 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

loop: handle on-demand devices correctly

2011-06-03T01:34:20+00:00

commit a1c15c59feee36267c43142a41152fbf7402afb6 upstream.

When finding or allocating a loop device, loop_probe() did not take
partition numbers into account so that it can result to a different
device. Consider following example:

$ sudo modprobe loop max_part=15
$ ls -l /dev/loop*
brw-rw---- 1 root disk 7,   0 2011-05-24 22:16 /dev/loop0
brw-rw---- 1 root disk 7,  16 2011-05-24 22:16 /dev/loop1
brw-rw---- 1 root disk 7,  32 2011-05-24 22:16 /dev/loop2
brw-rw---- 1 root disk 7,  48 2011-05-24 22:16 /dev/loop3
brw-rw---- 1 root disk 7,  64 2011-05-24 22:16 /dev/loop4
brw-rw---- 1 root disk 7,  80 2011-05-24 22:16 /dev/loop5
brw-rw---- 1 root disk 7,  96 2011-05-24 22:16 /dev/loop6
brw-rw---- 1 root disk 7, 112 2011-05-24 22:16 /dev/loop7
$ sudo mknod /dev/loop8 b 7 128
$ sudo losetup /dev/loop8 ~/temp/disk-with-3-parts.img
$ sudo losetup -a
/dev/loop128: [0805]:278201 (/home/namhyung/temp/disk-with-3-parts.img)
$ ls -l /dev/loop*
brw-rw---- 1 root disk 7,    0 2011-05-24 22:16 /dev/loop0
brw-rw---- 1 root disk 7,   16 2011-05-24 22:16 /dev/loop1
brw-rw---- 1 root disk 7, 2048 2011-05-24 22:18 /dev/loop128
brw-rw---- 1 root disk 7, 2049 2011-05-24 22:18 /dev/loop128p1
brw-rw---- 1 root disk 7, 2050 2011-05-24 22:18 /dev/loop128p2
brw-rw---- 1 root disk 7, 2051 2011-05-24 22:18 /dev/loop128p3
brw-rw---- 1 root disk 7,   32 2011-05-24 22:16 /dev/loop2
brw-rw---- 1 root disk 7,   48 2011-05-24 22:16 /dev/loop3
brw-rw---- 1 root disk 7,   64 2011-05-24 22:16 /dev/loop4
brw-rw---- 1 root disk 7,   80 2011-05-24 22:16 /dev/loop5
brw-rw---- 1 root disk 7,   96 2011-05-24 22:16 /dev/loop6
brw-rw---- 1 root disk 7,  112 2011-05-24 22:16 /dev/loop7
brw-r--r-- 1 root root 7,  128 2011-05-24 22:17 /dev/loop8

After this patch, /dev/loop8 - instead of /dev/loop128 - was
accessed correctly.

In addition, 'range' passed to blk_register_region() should
include all range of dev_t that LOOP_MAJOR can address. It does
not need to be limited by partition numbers unless 'max_loop'
param was specified.

Signed-off-by: Namhyung Kim 
Cc: Laurent Vivier 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

loop: limit 'max_part' module param to DISK_MAX_PARTS

2011-06-03T01:34:20+00:00

commit 78f4bb367fd147a0e7e3998ba6e47109999d8814 upstream.

The 'max_part' parameter controls the number of maximum partition
a loop block device can have. However if a user specifies very
large value it would exceed the limitation of device minor number
and can cause a kernel panic (or, at least, produce invalid
device nodes in some cases).

On my desktop system, following command kills the kernel. On qemu,
it triggers similar oops but the kernel was alive:

$ sudo modprobe loop max_part0000
 ------------[ cut here ]------------
 kernel BUG at /media/Linux_Data/project/linux/fs/sysfs/group.c:65!
 invalid opcode: 0000 [#1] SMP
 last sysfs file:
 CPU 0
 Modules linked in: loop(+)

 Pid: 43, comm: insmod Tainted: G        W   2.6.39-qemu+ #155 Bochs Bochs
 RIP: 0010:[]  [] internal_create_group=
+0x2a/0x170
 RSP: 0018:ffff880007b3fde8  EFLAGS: 00000246
 RAX: 00000000ffffffef RBX: ffff880007b3d878 RCX: 00000000000007b4
 RDX: ffffffff8152da50 RSI: 0000000000000000 RDI: ffff880007b3d878
 RBP: ffff880007b3fe38 R08: ffff880007b3fde8 R09: 0000000000000000
 R10: ffff88000783b4a8 R11: ffff880007b3d878 R12: ffffffff8152da50
 R13: ffff880007b3d868 R14: 0000000000000000 R15: ffff880007b3d800
 FS:  0000000002137880(0063) GS:ffff880007c00000(0000) knlGS:00000000000000=
00
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000422680 CR3: 0000000007b50000 CR4: 00000000000006b0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 0000000000000000 DR7: 0000000000000000
 Process insmod (pid: 43, threadinfo ffff880007b3e000, task ffff880007afb9c=
0)
 Stack:
  ffff880007b3fe58 ffffffff811e66dd ffff880007b3fe58 ffffffff811e570b
  0000000000000010 ffff880007b3d800 ffff880007a7b390 ffff880007b3d868
  0000000000400920 ffff880007b3d800 ffff880007b3fe48 ffffffff8113cfc8
 Call Trace:
  [] ? device_add+0x4bc/0x5af
  [] ? dev_set_name+0x3c/0x3e
  [] sysfs_create_group+0xe/0x12
  [] blk_trace_init_sysfs+0x14/0x16
  [] blk_register_queue+0x47/0xf7
  [] add_disk+0xdf/0x290
  [] loop_init+0xeb/0x1b8 [loop]
  [] ? 0xffffffffa0005fff
  [] do_one_initcall+0x7a/0x12e
  [] sys_init_module+0x9c/0x1e0
  [] system_call_fastpath+0x16/0x1b
 Code: c3 55 48 89 e5 41 57 41 56 41 89 f6 41 55 41 54 49 89 d4 53 48 89 fb=
 48 83 ec 28 48 85 ff 74 0b 85 f6 75 0b 48 83 7f 30 00 75 14 <0f> 0b eb fe =
48 83 7f 30 00 b9 ea ff ff ff 0f 84 18 01 00 00 49
 RIP  [] internal_create_group+0x2a/0x170
  RSP 
 ---[ end trace a123eb592043acad ]---

Signed-off-by: Namhyung Kim 
Cc: Laurent Vivier 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: don't block events on excl write for non-optical devices

2011-06-03T01:33:43+00:00

commit d4dc210f69bcb0b4bef5a83b1c323817be89bad1 upstream.

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

Signed-off-by: Tejun Heo 
Reported-by: Kay Sievers 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

paride: Convert to bdops->check_events()

2011-06-03T01:33:42+00:00

commit b1b56b93f331bd61492fdb99e7986f7a528ca730 upstream.

Convert paride drivers from ->media_changed() to ->check_events().

pcd and pd buffer and clear events after reporting; however, pf
unconditionally reports MEDIA_CHANGE and will generate spurious events
when polled.

Signed-off-by: Tejun Heo 
Cc: Jens Axboe 
Cc: Kay Sievers 
Cc: Tim Waugh 
Signed-off-by: Greg Kroah-Hartman

cciss: fix lost command issue

2011-04-14T20:01:58+00:00

commit 1ddd5049545e0aa1a0ed19bca4d9c9c3ce1ac8a2 upstream.

Under certain workloads a command may seem to get lost. IOW, the Smart Array
thinks all commands have been completed but we still have commands in our
completion queue. This may lead to system instability, filesystems going
read-only, or even panics depending on the affected filesystem. We add an
extra read to force the write to complete.

Testing shows this extra read avoids the problem.

Signed-off-by: Mike Miller 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: kill loop_mutex

2011-03-03T16:53:25+00:00

Following steps lead to deadlock in kernel:

dd if=/dev/zero of=img bs=512 count=1000
losetup -f img
mkfs.ext2 /dev/loop0
mount -t ext2 -o loop /dev/loop0 mnt
umount mnt/

Stacktrace:
[] irq_exit+0x36/0x59
[] smp_apic_timer_interrupt+0x6b/0x75
[] apic_timer_interrupt+0x31/0x38
[] mutex_spin_on_owner+0x54/0x5b
[] lo_release+0x12/0x67 [loop]
[] __blkdev_put+0x7c/0x10c
[] fput+0xd5/0x1aa
[] loop_clr_fd+0x1a9/0x1b1 [loop]
[] lo_release+0x39/0x67 [loop]
[] __blkdev_put+0x7c/0x10c
[] deactivate_locked_super+0x17/0x36
[] sys_umount+0x27e/0x2a5
[] sys_oldumount+0xb/0xe
[] sysenter_do_call+0x12/0x26
[] 0xffffffff

Regression since 2a48fc0ab24241755dc9, which introduced the private
loop_mutex as part of the BKL removal process.

As per [1], the mutex can be safely removed.

[1] http://www.gossamer-threads.com/lists/linux/kernel/1341930

Addresses: https://bugzilla.novell.com/show_bug.cgi?id=669394
Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=29172

Signed-off-by: Petr Uzel 
Cc: stable@kernel.org
Reviewed-by: Nikanth Karthikesan 
Acked-by: Arnd Bergmann 
Signed-off-by: Jens Axboe

Merge branch 'for-linus' of git://neil.brown.name/md

2011-02-25T19:13:26+00:00

* 'for-linus' of git://neil.brown.name/md:
  md: Fix - again - partition detection when array becomes active
  Fix over-zealous flush_disk when changing device size.
  md: avoid spinlock problem in blk_throtl_exit
  md: correctly handle probe of an 'mdp' device.
  md: don't set_capacity before array is active.
  md: Fix raid1->raid0 takeover

Fix over-zealous flush_disk when changing device size.

2011-02-24T06:25:47+00:00

There are two cases when we call flush_disk.
In one, the device has disappeared (check_disk_change) so any
data will hold becomes irrelevant.
In the oter, the device has changed size (check_disk_size_change)
so data we hold may be irrelevant.

In both cases it makes sense to discard any 'clean' buffers,
so they will be read back from the device if needed.

In the former case it makes sense to discard 'dirty' buffers
as there will never be anywhere safe to write the data.  In the
second case it *does*not* make sense to discard dirty buffers
as that will lead to file system corruption when you simply enlarge
the containing devices.

flush_disk calls __invalidate_devices.
__invalidate_device calls both invalidate_inodes and invalidate_bdev.

invalidate_inodes *does* discard I_DIRTY inodes and this does lead
to fs corruption.

invalidate_bev *does*not* discard dirty pages, but I don't really care
about that at present.

So this patch adds a flag to __invalidate_device (calling it
__invalidate_device2) to indicate whether dirty buffers should be
killed, and this is passed to invalidate_inodes which can choose to
skip dirty inodes.

flusk_disk then passes true from check_disk_change and false from
check_disk_size_change.

dm avoids tripping over this problem by calling i_size_write directly
rathher than using check_disk_size_change.

md does use check_disk_size_change and so is affected.

This regression was introduced by commit 608aeef17a which causes
check_disk_size_change to call flush_disk, so it is suitable for any
kernel since 2.6.27.

Cc: stable@kernel.org
Acked-by: Jeff Moyer 
Cc: Andrew Patterson 
Cc: Jens Axboe 
Signed-off-by: NeilBrown