linux.git/drivers/block/nbd.c, branch v2.6.29

nbd: fix I/O hang on disconnected nbds

2009-02-11T22:25:37+00:00

Fix a problem that causes I/O to a disconnected (or partially initialized)
nbd device to hang indefinitely.  To reproduce:

# ioctl NBD_SET_SIZE_BLOCKS /dev/nbd23 514048
# dd if=/dev/nbd23 of=/dev/null bs=4096 count=1

...hangs...

This can also occur when an nbd device loses its nbd-client/server
connection.  Although we clear the queue of any outstanding I/Os after the
client/server connection fails, any additional I/Os that get queued later
will hang.

This bug may also be the problem reported in this bug report:
http://bugzilla.kernel.org/show_bug.cgi?id=12277

Testing would need to be performed to determine if the two issues are the
same.

This problem was introduced by the new request handling thread code ("NBD:
allow nbd to be used locally", 3/2008), which entered into mainline around
2.6.25.

The fix, which is fairly simple, is to restore the check for lo->sock
being NULL in do_nbd_request.  This causes I/O to an uninitialized nbd to
immediately fail with an I/O error, as it did prior to the introduction of
this bug.

Signed-off-by: Paul Clements 
Reported-by: Jon Nelson 
Acked-by: Pavel Machek 
Cc: 		[2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nbd: do not allow two clients at the same time

2009-01-16T00:39:38+00:00

Two nbd-clients at same time are bad idea, and cause WARN_ON from nbd in
2.6.28-rc7 from sysfs_add_one.  This simply prevents that from happening.

To reproduce:

 cat /dev/zero | head -c 10000000 > /tmp/delme.fstest.fs
 nbd-server 9100 -l /anyone.can.connect > /tmp/delme.fstest.fs &
 sleep 1
 nbd-client localhost 9100 /dev/nd0 &
 nbd-client localhost 9100 /dev/nd0 &

Signed-off-by: Pavel Machek 
Acked-by: Paul Clements 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nbd: tell the block layer that it is not a rotational device

2008-12-29T07:29:50+00:00

Then we can get rid of that manual elevator type fiddling.

Signed-off-by: Jens Axboe

block: get rid of elevator_t typedef

2008-12-29T07:29:50+00:00

Just use struct elevator_queue everywhere instead.

Signed-off-by: Jens Axboe

[PATCH] switch nbd

2008-10-21T11:47:53+00:00

NB: nbd_ioctl() appears to be racy; BKL is held, but doesn't really
help, AFAICS.  Left as-is for now, but it'll need fixing.

Signed-off-by: Al Viro

[PATCH] beginning of methods conversion

2008-10-21T11:47:32+00:00

To keep the size of changesets sane we split the switch by drivers;
to keep the damn thing bisectable we do the following:
	1) rename the affected methods, add ones with correct
prototypes, make (few) callers handle both.  That's this changeset.
	2) for each driver convert to new methods.  *ALL* drivers
are converted in this series.
	3) kill the old (renamed) methods.

Note that it _is_ a flagday; all in-tree drivers are converted and by the
end of this series no trace of old methods remain.  The only reason why
we do that this way is to keep the damn thing bisectable and allow per-driver
debugging if anything goes wrong.

New methods:
	open(bdev, mode)
	release(disk, mode)
	ioctl(bdev, mode, cmd, arg)		/* Called without BKL */
	compat_ioctl(bdev, mode, cmd, arg)
	locked_ioctl(bdev, mode, cmd, arg)	/* Called with BKL, legacy */

Signed-off-by: Al Viro

x86: sysfs: kill owner field from attribute

2008-10-20T15:52:42+00:00

Tejun's commit 7b595756ec1f49e0049a9e01a1298d53a7faaa15 made sysfs
attribute->owner unnecessary.  But the field was left in the structure to
ease the merge.  It's been over a year since that change and it is now
time to start killing attribute->owner along with its users - one arch at
a time!

This patch is attempt #1 to get rid of attribute->owner only for
CONFIG_X86_64 or CONFIG_X86_32 .  We will deal with other arches later on
as and when possible - avr32 will be the next since that is something I
can test.  Compile (make allyesconfig / make allmodconfig / custom config)
and boot tested.

akpm: the idea is that we put the declaration of sttribute.owner inside
`#ifndef CONFIG_X86'.  But that proved to be too ambitious for now because
new usages kept on turning up in subsystem trees.

[akpm: remove the ifdef for now]
Signed-off-by: Parag Warudkar 
Cc: Greg KH 
Cc: Ingo Molnar 
Cc: Tejun Heo 
Cc: Len Brown 
Cc: Jens Axboe 
Cc: Jean Delvare 
Cc: Roland Dreier 
Cc: David Brownell 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block: implement and use {disk|part}_to_dev()

2008-10-09T06:56:07+00:00

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 
Signed-off-by: Jens Axboe

nbd: fix memory leak of nbd_dev array

2008-08-20T22:40:30+00:00

We leak the memory allocated for the nbd_dev array at multiple places.
Fix them by either adding a kfree() or by rearranging code to return
before we allocate the memory.

Signed-off-by: Sven Wegener 
Cc: Paul Clements 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

2008-04-29T15:18:03+00:00

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: Skip I/O merges when disabled
  block: add large command support
  block: replace sizeof(rq->cmd) with BLK_MAX_CDB
  ide: use blk_rq_init() to initialize the request
  block: use blk_rq_init() to initialize the request
  block: rename and export rq_init()
  block: no need to initialize rq->cmd with blk_get_request
  block: no need to initialize rq->cmd in prepare_flush_fn hook
  block/blk-barrier.c:blk_ordered_cur_seq() mustn't be inline
  block/elevator.c:elv_rq_merge_ok() mustn't be inline
  block: make queue flags non-atomic
  block: add dma alignment and padding support to blk_rq_map_kern
  unexport blk_max_pfn
  ps3disk: Remove superfluous cast
  block: make rq_init() do a full memset()
  relay: fix splice problem