Add xen-backend:vbd module alias to the xen-blkback module. This allows
automatic loading of the module.
Signed-off-by: NBastian Blank <waldi@debian.org>
Acked-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Running RING_FINAL_CHECK_FOR_REQUESTS from make_response is a bad
idea. It means that in-flight I/O is essentially blocking continued
batches. This essentially kills throughput on frontends which unplug
(or even just notify) early and rightfully assume addtional requests
will be picked up on time, not synchronously.
Signed-off-by: NDaniel Stodden <daniel.stodden@citrix.com>
[v1: Rebased and fixed compile problems]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Jens' back-merge commit 698567f3 ("Merge commit 'v2.6.39' into
for-2.6.40/core") was incorrectly done, and re-introduced the
DISK_EVENT_MEDIA_CHANGE lines that had been removed earlier in commits

 - 9fd097b1 ("block: unexport DISK_EVENT_MEDIA_CHANGE for
   legacy/fringe drivers")

 - 7eec77a1 ("ide: unexport DISK_EVENT_MEDIA_CHANGE for ide-gd
   and ide-cd")

because of conflicts with the "g->flags" updates near-by by commit
d4dc210f ("block: don't block events on excl write for non-optical
devices")

As a result, we re-introduced the hanging behavior due to infinite disk
media change reports.

Tssk, tssk, people! Don't do back-merges at all, and *definitely* don't
do them to hide merge conflicts from me - especially as I'm likely
better at merging them than you are, since I do so many merges.
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

blkbk->pending_pages can be NULL here so I added a check for it.
Signed-off-by: NDan Carpenter <error27@gmail.com>
[v1: Redid the loop a bit]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

...because vbd_size() dereferences bd_disk if bd_part is NULL.

Signed-off-by: Laszlo Ersek<lersek@redhat.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

It is easier to figure out the context by reading SCSI_SENSE_BUFFERSIZE
instead of plain '96'.
Signed-off-by: NLiu Yuan <tailai.ly@taobao.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Wire up the virtio_driver config_changed method to get notified about
config changes raised by the host.  For now we just re-read the device
size to support online resizing of devices, but once we add more
attributes that might be changeable they could be added as well.

Note that the config_changed method is called from irq context, so
we'll have to use the workqueue infrastructure to provide us a proper
user context for our changes.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Plan to remove floppy_disable_hlt in 2012, an ancient
workaround with comments that it should be removed.

This allows us to remove clutter and a run-time branch
from the idle code.

WARN_ONCE() on invocation until it is removed.

cc: x86@kernel.org
cc: stable@kernel.org # .39.x
Signed-off-by: NLen Brown <len.brown@intel.com>

The 'max_part' parameter determines how many partitions are supported
on each nbd device. However the actual number can be changed to the
power of 2 minus 1 form during the module initialization as
alloc_disk() is called with (1 << part_shift) for some reason.

So adjust 'max_part' also at least for consistency with loop and brd.
It is exported via sysfs already, and a user should check this value
after module loading if [s]he wants to use that number correctly
(i.e. fdisk or something).
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

The 'max_part' parameter controls the number of maximum partition
a nbd 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 oops (or, at least, produce invalid device
nodes in some cases).

In addition, specifying large 'nbds_max' value causes same
problem for the same reason.

On my desktop, following command results to the kernel bug:

$ sudo modprobe nbd max_part=100000
 kernel BUG at /media/Linux_Data/project/linux/fs/sysfs/group.c:65!
 invalid opcode: 0000 [#1] SMP
 last sysfs file: /sys/devices/virtual/block/nbd4/range
 CPU 1
 Modules linked in: nbd(+) bridge stp llc kvm_intel kvm asus_atk0110 sg sr_mod cdrom

 Pid: 2522, comm: modprobe Tainted: G        W   2.6.39-leonard+ #159 System manufacturer System Product Name/P5G41TD-M PRO
 RIP: 0010:[<ffffffff8115aa08>]  [<ffffffff8115aa08>] internal_create_group+0x2f/0x166
 RSP: 0018:ffff8801009f1de8  EFLAGS: 00010246
 RAX: 00000000ffffffef RBX: ffff880103920478 RCX: 00000000000a7bd3
 RDX: ffffffff81a2dbe0 RSI: 0000000000000000 RDI: ffff880103920478
 RBP: ffff8801009f1e38 R08: ffff880103920468 R09: ffff880103920478
 R10: ffff8801009f1de8 R11: ffff88011eccbb68 R12: ffffffff81a2dbe0
 R13: ffff880103920468 R14: 0000000000000000 R15: ffff880103920400
 FS:  00007f3c49de9700(0000) GS:ffff88011f800000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 00007f3b7fe7c000 CR3: 00000000cd58d000 CR4: 00000000000406e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process modprobe (pid: 2522, threadinfo ffff8801009f0000, task ffff8801009a93a0)
 Stack:
  ffff8801009f1e58 ffffffff812e8f6e ffff8801009f1e58 ffffffff812e7a80
  ffff880000000010 ffff880103920400 ffff8801002fd0c0 ffff880103920468
  0000000000000011 ffff880103920400 ffff8801009f1e48 ffffffff8115ab6a
 Call Trace:
  [<ffffffff812e8f6e>] ? device_add+0x4f1/0x5e4
  [<ffffffff812e7a80>] ? dev_set_name+0x41/0x43
  [<ffffffff8115ab6a>] sysfs_create_group+0x13/0x15
  [<ffffffff810b857e>] blk_trace_init_sysfs+0x14/0x16
  [<ffffffff811ee58b>] blk_register_queue+0x4c/0xfd
  [<ffffffff811f3bdf>] add_disk+0xe4/0x29c
  [<ffffffffa007e2ab>] nbd_init+0x2ab/0x30d [nbd]
  [<ffffffffa007e000>] ? 0xffffffffa007dfff
  [<ffffffff8100020f>] do_one_initcall+0x7f/0x13e
  [<ffffffff8107ab0a>] sys_init_module+0xa1/0x1e3
  [<ffffffff814f3542>] system_call_fastpath+0x16/0x1b
 Code: 41 57 41 56 41 55 41 54 53 48 83 ec 28 0f 1f 44 00 00 48 89 fb 41 89 f6 49 89 d4 48 85 ff 74 0b 85 f6 75 0b 48 83
  7f 30 00 75 14 <0f> 0b eb fe b9 ea ff ff ff 48 83 7f 30 00 0f 84 09 01 00 00 49
 RIP  [<ffffffff8115aa08>] internal_create_group+0x2f/0x166
  RSP <ffff8801009f1de8>
 ---[ end trace 753285ffbf72c57c ]---
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: stable@kernel.org
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Unlike kernel_sendmsg(), kernel_recvmsg() requires passing flags explicitly
via last parameter instead of struct msghdr.msg_flags. Therefore calls to
sock_xmit(lo, 0, ..., MSG_WAITALL) have not been processed properly by tcp
layer wrt. the flag. Fix it.
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Export 'max_loop' and 'max_part' parameters to sysfs so user can know
that how many devices are allowed and how many partitions are supported.

If 'max_loop' is 0, there is no restriction on the number of loop devices.
User can create/use the devices as many as minor numbers available. If
'max_part' is 0, it means simply the device doesn't support partitioning.

Also note that 'max_part' can be adjusted to power of 2 minus 1 form if
needed. User should check this value after the module loading if he/she
want to use that number correctly (i.e. fdisk, mknod, etc.).
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Export 'rd_nr', 'rd_size' and 'max_part' parameters to sysfs so user can
know that how many devices are allowed, how big each device is and how
many partitions are supported. If 'max_part' is 0, it means simply the
device doesn't support partitioning.

Also note that 'max_part' can be adjusted to power of 2 minus 1 form if
needed. User should check this value after the module loading if he/she
want to use that number correctly (i.e. fdisk, mknod, etc.).
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

If 'rd_nr' param was not specified, 16 (can be adjusted via
CONFIG_BLK_DEV_RAM_COUNT) devices would be created by default
but comment said 1. Fix it.
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

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: NNamhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Cc: stable@kernel.org
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

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: [<ffffffff81110a9a>] 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:[<ffffffff81110a9a>]  [<ffffffff81110a9a>] 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:
  [<ffffffff81143c0a>] kobject_add_internal+0xdf/0x1a0
  [<ffffffff81143da1>] kobject_add_varg+0x41/0x50
  [<ffffffff81143e6b>] kobject_add+0x64/0x66
  [<ffffffff8113bbe7>] blk_register_queue+0x5f/0xb8
  [<ffffffff81140f72>] add_disk+0xdf/0x289
  [<ffffffffa00040df>] brd_init+0xdf/0x1aa [brd]
  [<ffffffffa0004000>] ? 0xffffffffa0003fff
  [<ffffffffa0004000>] ? 0xffffffffa0003fff
  [<ffffffff8100020a>] do_one_initcall+0x7a/0x12e
  [<ffffffff8108516c>] sys_init_module+0x9c/0x1dc
  [<ffffffff812ff4bb>] 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  [<ffffffff81110a9a>] sysfs_create_dir+0x2d/0xae
  RSP <ffff880007b15d78>
 CR2: 0000000000000058
 ---[ end trace aebb1175ce1f6739 ]---
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Cc: stable@kernel.org
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

brd_refcnt, brd_offset, brd_sizelimit and brd_blocksize in struct
brd_device seem to be copied from struct loop_device but they're
not used anywhere. Let get rid of them.
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

If we get a notification that the image header has changed, check for
a change in the image size.
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

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: NNamhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Cc: stable@kernel.org
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

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:[<ffffffff8113ce61>]  [<ffffffff8113ce61>] 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:
  [<ffffffff811e66dd>] ? device_add+0x4bc/0x5af
  [<ffffffff811e570b>] ? dev_set_name+0x3c/0x3e
  [<ffffffff8113cfc8>] sysfs_create_group+0xe/0x12
  [<ffffffff810b420e>] blk_trace_init_sysfs+0x14/0x16
  [<ffffffff8116a090>] blk_register_queue+0x47/0xf7
  [<ffffffff8116f527>] add_disk+0xdf/0x290
  [<ffffffffa00060eb>] loop_init+0xeb/0x1b8 [loop]
  [<ffffffffa0006000>] ? 0xffffffffa0005fff
  [<ffffffff8100020a>] do_one_initcall+0x7a/0x12e
  [<ffffffff81096804>] sys_init_module+0x9c/0x1e0
  [<ffffffff813329bb>] 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  [<ffffffff8113ce61>] internal_create_group+0x2a/0x170
  RSP <ffff880007b3fde8>
 ---[ end trace a123eb592043acad ]---
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Cc: stable@kernel.org
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

In file included from drivers/block/drbd/drbd_main.c:54:                        drivers/block/drbd/drbd_int.h:1190: warning: parameter has incomplete type

Forward declarations of enums do not work.

Fix it unpleasantly by moving the prototype.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NLars Ellenberg <drbd-dev@lists.linbit.com>
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>

Found these with the help of ispell -l.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>

An administrative detach used to request a state change directly to D_DISKLESS,
first suspending IO to avoid the last put_ldev() occuring from an endio handler,
potentially in irq context.

This is not enough on the receiving side (typically secondary), we may miss
some peer_req on the way to local disk, which then may do the last put_ldev()
from their drbd_peer_request_endio().

This patch makes the detach always go through the intermediate D_FAILED state.
We may consider to rename it D_DETACHING.

Alternative approach would be to create yet an other work item to be scheduled
on the worker, do the destructor work from there, and get the timing right.

manually picked commit 564040f from the drbd 8.4 branch.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

The old (optimistic) implementation could shrink the bio size
on an primary device.

Shrinking the bio size on a primary device is bad. Since there
we might get BIOs with the old (bigger) size shortly after
we published the new size.

The new implementation is more conservative, and eventually
increases the max_bio_size on a primary device (which is valid).
It does so, when it knows the local limit AND the remote limit.

 We cache the last seen max_bio_size of the peer in the meta
 data, and rely on that, to make the operation of single
 nodes more efficient.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

It seems that the real cause of all the issues where that
we did not noticed in drbd_try_connect() when the other
guy closes one socket if the round trip time gets higher
than 100ms. There were that 100ms hard coded!
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

It is no longer sufficient to trigger on local WRITE,
we need to check on (rq_state & RQ_IN_ACT_LOG)
before calling drbd_al_complete_io also in the error path.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

If there is no replication traffic within the idle timeout
(ping-int seconds), DRBD will send a P_PING,
and adjust the timeout to ping-timeout.

If there is no P_PING_ACK received within this ping-timeout,
DRBD finally drops the connection, and tries to re-establish it.

To decide which timeout was active, we compared the current timeout
with the ping-timeout, and dropped the connection, if that was the case.

By default, ping-int is 10 seconds, ping-timeout is 500 ms.

Unfortunately, if you configure ping-timeout to be the same as ping-int,
expiry of the idle-timeout had been mistaken for a missing ping ack,
and caused an immediate reconnection attempt.

Fix:
Allow both timeouts to be equal, use a local variable
to store which timeout is active.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

We limit ourselves to a configurable maximum number of pages used as
temporary bio pages.

If the configured "max_buffers" is not big enough to match the bandwidth
of the respective deployment, a distributed deadlock could be triggered
by e.g. fast online verify and heavy application IO.

TCP connections would block on congestion, because both receivers
would wait on pages to become available.

Fortunately the respective senders in this case would be able to give
back some pages already. So do that.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

In case a write failes on the local disk, go into D_INCONSISTENT
disk state. That causes future reads of that block to be shipped
to the peer.

Read retry remote was already in place.

Actually the documentation needs to get fixed now. Since the
application is still shielded from the error. (as long as we have
only a single disk failing) The difference to detach is that
we keep the disk. And therefore might keep all the other, still
working sectors up to date.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

After discovering that wide use of prefetch on modern CPUs
could be a net loss instead of a win, net drivers which were
relying on the implicit inclusion of prefetch.h via the list
headers showed up in the resulting cleanup fallout.  Give
them an explicit include via the following $0.02 script.

 =========================================
 #!/bin/bash
 MANUAL=""
 for i in `git grep -l 'prefetch(.*)' .` ; do
 	grep -q '<linux/prefetch.h>' $i
 	if [ $? = 0 ] ; then
 		continue
 	fi

 	(	echo '?^#include <linux/?a'
 		echo '#include <linux/prefetch.h>'
 		echo .
 		echo w
 		echo q
 	) | ed -s $i > /dev/null 2>&1
 	if [ $? != 0 ]; then
 		echo $i needs manual fixup
 		MANUAL="$i $MANUAL"
 	fi
 done
 echo ------------------- 8\<----------------------
 echo vi $MANUAL
 =========================================
Signed-off-by: NPaul <paul.gortmaker@windriver.com>
[ Fixed up some incorrect #include placements, and added some
  non-network drivers and the fib_trie.c case    - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NSage Weil <sage@newdream.net>

The sector number on empty barrier requests may (will?) be -1, which,
given that it's being treated as unsigned 64-bit quantity, will almost
always exceed the actual (virtual) disk's size.

Inspired by Konrad's "When writting barriers set the sector number to
zero...".

While at it also add overflow checking to the math in vbd_translate().
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The rbd driver currently splits bios when they span an object boundary.
However, the blk_end_request expects the completions to roll up the results
in block device order, and the split rbd/ceph ops can complete in any
order.  This patch adds a struct rbd_req_coll to track completion of split
requests and ensures that the results are passed back up to the block layer
in order.

This fixes errors where the file system gets completion of a read operation
that spans an object boundary before the data has actually arrived.  The
bug is easily reproduced with iozone with a working set larger than
available RAM.
Reported-by: NFyodor Ustinov <ufm@ufm.su>
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

vbd_resize() up_read()'s xs_state.suspend_mutex twice in a row via double
xenbus_transaction_end() calls. The next down_read() in
xenbus_transaction_start() (at eg. the next resize attempt) hangs.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=618317Acked-by: NJan Beulich <jbeulich@novell.com>
Acked-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NLaszlo Ersek <lersek@redhat.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>