Граф коммитов

133 Коммитов

Автор SHA1 Сообщение Дата
Jens Axboe aafb1eecbb nbd: switch to using blk_queue_write_cache()
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-04-12 16:00:39 -06:00
Arnd Bergmann 5e454c67fc nbd: use correct div_s64 helper
The do_div() macro now checks its arguments for the correct type,
and refuses anything other than u64, so we get a warning about
nbd_ioctl passing in an loff_t:

drivers/block/nbd.c: In function '__nbd_ioctl':
drivers/block/nbd.c:757:77: error: comparison of distinct pointer types lacks a cast [-Werror]

This changes the nbd code to use div_s64() instead, which takes
a signed argument.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 37091fdd83 ("nbd: Create size change events for userspace")
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-04 17:20:12 -07:00
Markus Pargmann 37091fdd83 nbd: Create size change events for userspace
The userspace needs to know when nbd devices are ready for use.
Currently no events are created for the userspace which doesn't work for
systemd.

See the discussion here: https://github.com/systemd/systemd/pull/358

This patch uses a central point to setup the nbd-internal sizes. A ioctl
to set a size does not lead to a visible size change. The size of the
block device will be kept at 0 until nbd is connected. As soon as it
connects, the size will be changed to the real value and a uevent is
created. When disconnecting, the blockdevice is set to 0 size and
another uevent is generated.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
2016-02-15 10:35:47 +01:00
Dan Streetman da6ccaaa79 nbd: ratelimit error msgs after socket close
Make the "Attempted send on closed socket" error messages generated in
nbd_request_handler() ratelimited.

When the nbd socket is shutdown, the nbd_request_handler() function emits
an error message for every request remaining in its queue.  If the queue
is large, this will spam a large amount of messages to the log.  There's
no need for a separate error message for each request, so this patch
ratelimits it.

In the specific case this was found, the system was virtual and the error
messages were logged to the serial port, which overwhelmed it.

Fixes: 4d48a542b4 ("nbd: fix I/O hang on disconnected nbds")
Signed-off-by: Dan Streetman <dan.streetman@canonical.com>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
2016-02-05 08:55:15 +01:00
Markus Pargmann d02cf53107 nbd: Move flag parsing to a function
nbd changes properties of the blockdevice depending on flags that were
received. This patch moves this flag parsing into a separate function
nbd_parse_flags().

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
2016-02-05 08:52:33 +01:00
Markus Pargmann 0e4f0f6f63 nbd: Cleanup reset of nbd and bdev after a disconnect
Group all variables that are reset after a disconnect into reset
functions. This patch adds two of these functions, nbd_reset() and
nbd_bdev_reset().

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
2016-02-05 08:52:32 +01:00
Markus Pargmann 1f7b5cf1be nbd: Timeouts are not user requested disconnects
It may be useful to know in the client that a connection timed out. The
current code returns success for a timeout.

This patch reports the error code -ETIMEDOUT for a timeout.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
2016-02-05 08:52:31 +01:00
Markus Pargmann 23272a6754 nbd: Remove signal usage
As discussed on the mailing list, the usage of signals for timeout
handling has a lot of potential issues. The nbd driver used for some
time signals for timeouts. These signals where able to get the threads
out of the blocking socket operations.

This patch removes all signal usage and uses a socket shutdown instead.
The socket descriptor itself is cleared later when the whole nbd device
is closed.

The tasks_lock is removed as we do not depend on this anymore. Instead
a new lock for the socket is introduced so we can safely work with the
socket in the timeout handler outside of the two main threads.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-02-05 08:52:25 +01:00
Markus Pargmann 27ea43fe2a nbd: Fix debugfs error handling
Static checker complains about the implemented error handling. It is
indeed wrong. We don't care about the return values of created debugfs
files.

We only have to check the return values of created dirs for NULL
pointer. If we use a null pointer as parent directory for files, this
may lead to debugfs files in wrong places.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
2016-02-03 11:02:56 +01:00
Al Viro 263a3df18f nbd: use ->compat_ioctl()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-08 21:20:32 -05:00
Oleg Nesterov be0e6f290f signal: turn dequeue_signal_lock() into kernel_dequeue_signal()
1. Rename dequeue_signal_lock() to kernel_dequeue_signal(). This
   matches another "for kthreads only" kernel_sigaction() helper.

2. Remove the "tsk" and "mask" arguments, they are always current
   and current->blocked. And it is simply wrong if tsk != current.

3. We could also remove the 3rd "siginfo_t *info" arg but it looks
   potentially useful. However we can simplify the callers if we
   change kernel_dequeue_signal() to accept info => NULL.

4. Remove _irqsave, it is never called from atomic context.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Markus Pargmann dcc909d90c nbd: Add locking for tasks
The timeout handling introduced in
	7e2893a16d (nbd: Fix timeout detection)
introduces a race condition which may lead to killing of tasks that are
not in nbd context anymore. This was not observed or reproducable yet.

This patch adds locking to critical use of task_recv and task_send to
avoid killing tasks that already left the NBD thread functions. This
lock is only acquired if a timeout occures or the nbd device
starts/stops.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Reviewed-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: 7e2893a16d ("nbd: Fix timeout detection")
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-08 14:21:24 -06:00
Markus Pargmann 22d109c1bb nbd: flags is a u32 variable
The flags variable is used as u32 variable. This patch changes the type
to be u32.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:23:01 -06:00
Markus Pargmann cad73b2703 nbd: Rename functions for clearness of recv/send path
This patch renames functions so that it is clear what the function does.
Otherwise it is not directly understandable what for example 'do_it' means.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:22:59 -06:00
Markus Pargmann 696697cb50 nbd: Change 'disconnect' to be boolean
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek  <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:22:58 -06:00
Markus Pargmann 30d53d9c11 nbd: Add debugfs entries
Add some debugfs files that help to understand the internal state of
NBD. This exports the different sizes, flags, tasks and so on.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:22:56 -06:00
Markus Pargmann 6521d39a64 nbd: Remove variable 'pid'
This patch uses nbd->task_recv to determine the value of the previously
used variable 'pid' for sysfs.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:22:55 -06:00
Markus Pargmann e78273c80b nbd: Move clear queue debug message
This message was a warning without a reason. This patch moves it into
nbd_clear_que and transforms it to a debug message.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:22:53 -06:00
Markus Pargmann 193918307f nbd: Remove 'harderror' and propagate error properly
Instead of a variable 'harderror' we can simply try to correctly
propagate errors to the userspace.

This patch removes the harderror variable and passes errors through
error pointers and nbd_do_it back to the userspace.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:22:52 -06:00
Markus Pargmann 260bbce403 nbd: restructure sock_shutdown
This patch restructures sock_shutdown to avoid having the main code path
in an if block.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:22:50 -06:00
Markus Pargmann 36e47bee7c nbd: sock_shutdown, remove conditional lock
Move the conditional lock from sock_shutdown into the surrounding code.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:22:49 -06:00
Markus Pargmann 7e2893a16d nbd: Fix timeout detection
At the moment the nbd timeout just detects hanging tcp operations. This
is not enough to detect a hanging or bad connection as expected of a
timeout.

This patch redesigns the timeout detection to include some more cases.
The timeout is now in relation to replies from the server. If the server
does not send replies within the timeout the connection will be shut
down.

The patch adds a continous timer 'timeout_timer' that is setup in one of
two cases:
 - The request list is empty and we are sending the first request out to
   the server. We want to have a reply within the given timeout,
   otherwise we consider the connection to be dead.
 - A server response was received. This means the server is still
   communicating with us. The timer is reset to the timeout value.

The timer is not stopped if the list becomes empty. It will just trigger
a timeout which will directly leave the handling routine again as the
request list is empty.

The whole patch does not use any additional explicit locking. The
list_empty() calls are safe to be used concurrently. The timer is locked
internally as we just use mod_timer and del_timer_sync().

The patch is based on the idea of Michal Belczyk with a previous
different implementation.

Cc: Michal Belczyk <belczyk@bsd.krakow.pl>
Cc: Hermann Lauer <Hermann.Lauer@iwr.uni-heidelberg.de>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Tested-by: Hermann Lauer <Hermann.Lauer@iwr.uni-heidelberg.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:22:47 -06:00
Jens Axboe 2bb4cd5cc4 block: have drivers use blk_queue_max_discard_sectors()
Some drivers use it now, others just set the limits field manually.
But in preparation for splitting this into a hard and soft limit,
ensure that they all call the proper function for setting the hw
limit for discards.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-17 08:41:53 -06:00
Ming Lei 9dcd137953 block: nbd: convert to blkdev_reread_part()
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-20 09:06:13 -06:00
Christoph Hellwig 9dc6c806b3 nbd: stop using req->cmd
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:40:44 -06:00
Christoph Hellwig 4f8c9510ba block: rename REQ_TYPE_SPECIAL to REQ_TYPE_DRV_PRIV
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:40:03 -06:00
Markus Pargmann de9ad6d4ed nbd: Return error pointer directly
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-02 12:39:28 -06:00
Markus Pargmann dab5313aa4 nbd: Return error code directly
By returning the error code directly, we can avoid the jump label
error_out.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-02 12:39:26 -06:00
Markus Pargmann e018e7570c nbd: Remove fixme that was already fixed
The mentioned problem is not present anymore.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-02 12:39:24 -06:00
Markus Pargmann d18509f597 nbd: Restructure debugging prints
dprintk has some name collisions with other frameworks and drivers. It
is also not necessary to have these custom debug print filters. Dynamic
debug offers the same amount of filtered debugging.

This patch replaces all dprintks with dev_dbg(). It also removes the
ioctl dprintk which prints the ingoing ioctls which should be
replaceable by strace or similar stuff.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-02 12:39:22 -06:00
Markus Pargmann b9c495bb6d nbd: Fix device bytesize type
The block subsystem uses loff_t to store the device size. Change the
type for nbd_device bytesize to loff_t.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-02 12:39:21 -06:00
Markus Pargmann d06df60b94 nbd: Replace kthread_create with kthread_run
kthread_run includes the wake_up_process() call, so instead of
kthread_create() followed by wake_up_process() we can use this macro.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-02 12:39:19 -06:00
Markus Pargmann 13e71d69cc nbd: Remove kernel internal header
The header is not included anywhere. Remove it and include the private
nbd_device struct in nbd.c.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-02 12:39:18 -06:00
Sudip Mukherjee ff6b8090e2 nbd: fix possible memory leak
we have already allocated memory for nbd_dev, but we were not
releasing that memory and just returning the error value.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Acked-by: Paul Clements <Paul.Clements@SteelEye.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
2015-03-05 08:51:03 +01:00
Mike Snitzer b277da0a8a block: disable entropy contributions for nonrot devices
Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set
QUEUE_FLAG_NONROT.

Historically, all block devices have automatically made entropy
contributions.  But as previously stated in commit e2e1a148 ("block: add
sysfs knob for turning off disk entropy contributions"):
    - On SSD disks, the completion times aren't as random as they
      are for rotational drives. So it's questionable whether they
      should contribute to the random pool in the first place.
    - Calling add_disk_randomness() has a lot of overhead.

There are more reliable sources for randomness than non-rotational block
devices.  From a security perspective it is better to err on the side of
caution than to allow entropy contributions from unreliable "random"
sources.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-04 10:55:32 -06:00
Hani Benhabiles 04cfac4e40 nbd: zero from and len fields in NBD_CMD_DISCONNECT.
Len field is already set to zero, but not the from field which is sent
as 0xfffffffffffffe00.  This makes no sense, and may cause confuse
server implementations doing sanity checks (qemu-nbd is an example.)

Signed-off-by: Hani Benhabiles <hani@linux.com>
Cc: Paul Clements <paul.clements@us.sios.com>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06 16:08:18 -07:00
Ingo Molnar 2fe5de9ce7 Merge branch 'sched/urgent' into sched/core, to avoid conflicts
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07 13:15:46 +02:00
Dongsheng Yang 8698a745d8 sched, treewide: Replace hardcoded nice values with MIN_NICE/MAX_NICE
Replace various -20/+19 hardcoded nice values with MIN_NICE/MAX_NICE.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/ff13819fd09b7a5dba5ab5ae797f2e7019bdfa17.1394532288.git.yangds.fnst@cn.fujitsu.com
Cc: devel@driverdev.osuosl.org
Cc: devicetree@vger.kernel.org
Cc: fcoe-devel@open-fcoe.org
Cc: linux390@de.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-s390@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: nbd-general@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: openipmi-developer@lists.sourceforge.net
Cc: qla2xxx-upstream@qlogic.com
Cc: linux-arch@vger.kernel.org
[ Consolidated the patches, twiddled the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-18 12:07:24 +02:00
Al Viro e25115786e switch nbd to sockfd_lookup/sockfd_put
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:10 -04:00
Kent Overstreet 4550dd6c6b block: Immutable bio vecs
This adds a mechanism by which we can advance a bio by an arbitrary
number of bytes without modifying the biovec: bio->bi_iter.bi_bvec_done
indicates the number of bytes completed in the current bvec.

Various driver code still needs to be updated to not refer to the bvec
directly before we can use this for interesting things, like efficient
bio splitting.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: drbd-user@lists.linbit.com
Cc: nbd-general@lists.sourceforge.net
2013-11-23 22:33:49 -08:00
Kent Overstreet 7988613b0e block: Convert bio_for_each_segment() to bvec_iter
More prep work for immutable biovecs - with immutable bvecs drivers
won't be able to use the biovec directly, they'll need to use helpers
that take into account bio->bi_iter.bi_bvec_done.

This updates callers for the new usage without changing the
implementation yet.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: Jim Paris <jim@jtan.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris <josh.h.morris@us.ibm.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Cc: support@lsi.com
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Quoc-Son Anh <quoc-sonx.anh@intel.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jan Kara <jack@suse.cz>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: drbd-user@lists.linbit.com
Cc: nbd-general@lists.sourceforge.net
Cc: cbe-oss-dev@lists.ozlabs.org
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Cc: linux-raid@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: DL-MPTFusionLinux@lsi.com
Cc: linux-scsi@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: linux-fsdevel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: linux-mm@kvack.org
Acked-by: Geoff Levand <geoff@infradead.org>
2013-11-23 22:33:49 -08:00
Paul Clements c378f70adb nbd: correct disconnect behavior
Currently, when a disconnect is requested by the user (via NBD_DISCONNECT
ioctl) the return from NBD_DO_IT is undefined (it is usually one of
several error codes).  This means that nbd-client does not know if a
manual disconnect was performed or whether a network error occurred.
Because of this, nbd-client's persist mode (which tries to reconnect after
error, but not after manual disconnect) does not always work correctly.

This change fixes this by causing NBD_DO_IT to always return 0 if a user
requests a disconnect.  This means that nbd-client can correctly either
persist the connection (if an error occurred) or disconnect (if the user
requested it).

Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Acked-by: Rob Landley <rob@landley.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:05 -07:00
Michal Belczyk 9532f149ee nbd: remove bogus BUG_ON in NBD_CLEAR_QUE
The NBD_CLEAR_QUE ioctl has been deprecated for quite some time (its job
is now done by two other ioctls).  We should stop trying to make bogus
assertions in it.  Also, user-level code should remove calls to
NBD_CLEAR_QUE, ASAP.

Signed-off-by: Michal Belczyk <belczyk@bsd.krakow.pl>
Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:05 -07:00
Kees Cook ffc8b30866 block: do not pass disk names as format strings
Disk names may contain arbitrary strings, so they must not be
interpreted as format strings.  It seems that only md allows arbitrary
strings to be used for disk names, but this could allow for a local
memory corruption from uid 0 into ring 0.

CVE-2013-2851

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:25 -07:00
Michal Belczyk 078be02b80 nbd: increase default and max request sizes
Raise the default max request size for nbd to 128KB (from 127KB) to get it
4KB aligned.  This patch also allows the max request size to be increased
(via /sys/block/nbd<x>/queue/max_sectors_kb) to 32MB.

The patch makes nbd network traffic more efficient by:
- reducing request fragmentation (4KB alignment)
- reducing the number of requests (fewer round trips, less network overhead)

Especially in high latency networks, larger request size can make a dramatic

Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: Michal Belczyk <belczyk@bsd.krakow.pl>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:07 -07:00
Alex Elder 398eb08555 nbd: fix sparse warning
I just fixed this in "drivers/block/rbd.c" and I noticed that
"drivers/block/nbd.c" has the same problem.  Fix a warning issued by
sparse by adding some lockdep annotations to indicate the queue lock gets
dropped (because it's held when do_nbd_request() is called) and
re-acquired within the function.

Signed-off-by: Alex Elder <elder@inktank.com>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Paul Clements <paul.clements@us.sios.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:22 -08:00
Paolo Bonzini a83e814b5b nbd: show read-only state in sysfs
Pass the read-only flag to set_device_ro, so that it will be visible to
the block layer and in sysfs.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:22 -08:00
Paolo Bonzini 3a2d63f879 nbd: fsync and kill block device on shutdown
There are two problems with shutdown in the NBD driver.

1: Receiving the NBD_DISCONNECT ioctl does not sync the filesystem.

   This patch adds the sync operation into __nbd_ioctl()'s
   NBD_DISCONNECT handler.  This is useful because BLKFLSBUF is restricted
   to processes that have CAP_SYS_ADMIN, and the NBD client may not
   possess it (fsync of the block device does not sync the filesystem,
   either).

2: Once we clear the socket we have no guarantee that later reads will
   come from the same backing storage.

   The patch adds calls to kill_bdev() in __nbd_ioctl()'s socket
   clearing code so the page cache is cleaned, lest reads that hit on the
   page cache will return stale data from the previously-accessible disk.

Example:

    # qemu-nbd -r -c/dev/nbd0 /dev/sr0
    # file -s /dev/nbd0
    /dev/stdin: # UDF filesystem data (version 1.5) etc.
    # qemu-nbd -d /dev/nbd0
    # qemu-nbd -r -c/dev/nbd0 /dev/sda
    # file -s /dev/nbd0
    /dev/stdin: # UDF filesystem data (version 1.5) etc.

While /dev/sda has:

    # file -s /dev/sda
    /dev/sda: x86 boot sector; etc.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Paul Clements <Paul.Clements@steeleye.com>
Cc: Alex Bligh <alex@alex.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:22 -08:00
Alex Bligh 75f187aba5 nbd: support FLUSH requests
Currently, the NBD device does not accept flush requests from the Linux
block layer.  If the NBD server opened the target with neither O_SYNC nor
O_DSYNC, however, the device will be effectively backed by a writeback
cache.  Without issuing flushes properly, operation of the NBD device will
not be safe against power losses.

The NBD protocol has support for both a cache flush command and a FUA
command flag; the server will also pass a flag to note its support for
these features.  This patch adds support for the cache flush command and
flag.  In the kernel, we receive the flags via the NBD_SET_FLAGS ioctl,
and map NBD_FLAG_SEND_FLUSH to the argument of blk_queue_flush.  When the
flag is active the block layer will send REQ_FLUSH requests, which we
translate to NBD_CMD_FLUSH commands.

FUA support is not included in this patch because all free software
servers implement it with a full fdatasync; thus it has no advantage over
supporting flush only.  Because I [Paolo] cannot really benchmark it in a
realistic scenario, I cannot tell if it is a good idea or not.  It is also
not clear if it is valid for an NBD server to support FUA but not flush.
The Linux block layer gives a warning for this combination, the NBD
protocol documentation says nothing about it.

The patch also fixes a small problem in the handling of flags: nbd->flags
must be cleared at the end of NBD_DO_IT, but the driver was not doing
that.  The bug manifests itself as follows.  Suppose you two different
client/server pairs to start the NBD device.  Suppose also that the first
client supports NBD_SET_FLAGS, and the first server sends
NBD_FLAG_SEND_FLUSH; the second pair instead does neither of these two
things.  Before this patch, the second invocation of NBD_DO_IT will use a
stale value of nbd->flags, and the second server will issue an error every
time it receives an NBD_CMD_FLUSH command.

This bug is pre-existing, but it becomes much more important after this
patch; flush failures make the device pretty much unusable, unlike

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Bligh <alex@alex.org.uk>
Acked-by: Paul Clements <Paul.Clements@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:22 -08:00
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00