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commit 8e3f8755545cc4a7f4da8e9ef76d6d32e0dca576 upstream.
Check that the ring does not have an insane amount of requests
(more than there could fit on the ring).
If we detect this case we will stop processing the requests
and wait until the XenBus disconnects the ring.
The existing check RING_REQUEST_CONS_OVERFLOW which checks for how
many responses we have created in the past (rsp_prod_pvt) vs
requests consumed (req_cons) and whether said difference is greater or
equal to the size of the ring, does not catch this case.
Wha the condition does check if there is a need to process more
as we still have a backlog of responses to finish. Note that both
of those values (rsp_prod_pvt and req_cons) are not exposed on the
shared ring.
To understand this problem a mini crash course in ring protocol
response/request updates is in place.
There are four entries: req_prod and rsp_prod; req_event and rsp_event
to track the ring entries. We are only concerned about the first two -
which set the tone of this bug.
The req_prod is a value incremented by frontend for each request put
on the ring. Conversely the rsp_prod is a value incremented by the backend
for each response put on the ring (rsp_prod gets set by rsp_prod_pvt when
pushing the responses on the ring). Both values can
wrap and are modulo the size of the ring (in block case that is 32).
Please see RING_GET_REQUEST and RING_GET_RESPONSE for the more details.
The culprit here is that if the difference between the
req_prod and req_cons is greater than the ring size we have a problem.
Fortunately for us, the '__do_block_io_op' loop:
rc = blk_rings->common.req_cons;
rp = blk_rings->common.sring->req_prod;
while (rc != rp) {
..
blk_rings->common.req_cons = ++rc; /* before make_response() */
}
will loop up to the point when rc == rp. The macros inside of the
loop (RING_GET_REQUEST) is smart and is indexing based on the modulo
of the ring size. If the frontend has provided a bogus req_prod value
we will loop until the 'rc == rp' - which means we could be processing
already processed requests (or responses) often.
The reason the RING_REQUEST_CONS_OVERFLOW is not helping here is
b/c it only tracks how many responses we have internally produced
and whether we would should process more. The astute reader will
notice that the macro RING_REQUEST_CONS_OVERFLOW provides two
arguments - more on this later.
For example, if we were to enter this function with these values:
blk_rings->common.sring->req_prod = X+31415 (X is the value from
the last time __do_block_io_op was called).
blk_rings->common.req_cons = X
blk_rings->common.rsp_prod_pvt = X
The RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, blk_rings->common.req_cons)
is doing:
req_cons - rsp_prod_pvt >= 32
Which is,
X - X >= 32 or 0 >= 32
And that is false, so we continue on looping (this bug).
If we re-use said macro RING_REQUEST_CONS_OVERFLOW and pass in the rp
instead (sring->req_prod) of rc, the this macro can do the check:
req_prod - rsp_prov_pvt >= 32
Which is,
X + 31415 - X >= 32 , or 31415 >= 32
which is true, so we can error out and break out of the function.
Unfortunatly the difference between rsp_prov_pvt and req_prod can be
at 32 (which would error out in the macro). This condition exists when
the backend is lagging behind with the responses and still has not finished
responding to all of them (so make_response has not been called), and
the rsp_prov_pvt + 32 == req_cons. This ends up with us not being able
to use said macro.
Hence introducing a new macro called RING_REQUEST_PROD_OVERFLOW which does
a simple check of:
req_prod - rsp_prod_pvt > RING_SIZE
And with the X values from above:
X + 31415 - X > 32
Returns true. Also not that if the ring is full (which is where
the RING_REQUEST_CONS_OVERFLOW triggered), we would not hit the
same condition:
X + 32 - X > 32
Which is false.
Lets use that macro.
Note that in v5 of this patchset the macro was different - we used an
earlier version.
[v1: Move the check outside the loop]
[v2: Add a pr_warn as suggested by David]
[v3: Use RING_REQUEST_CONS_OVERFLOW as suggested by Jan]
[v4: Move wake_up after kthread_stop as suggested by Jan]
[v5: Use RING_REQUEST_PROD_OVERFLOW instead]
[v6: Use RING_REQUEST_PROD_OVERFLOW - Jan's version]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit c378f70adbc1bbecd9e6db145019f14b2f688c7c upstream.
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust device pointer name]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit ffc8b30866879ed9ba62bd0a86fecdbd51cd3d19 upstream.
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust device pointer name in nbd.c]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit e9986f303dc0f285401de28cf96f42f4dd23a4a1 upstream.
If a virtio disk is open in guest and a disk resize operation is done,
(virsh blockresize), new size is not visible to tools like "fdisk -l".
This seems to be happening as we update only part->nr_sects and not
bdev->bd_inode size.
Call revalidate_disk() which should take care of it. I tested growing disk
size of already open disk and it works for me.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 03f47e888daf56c8e9046c674719a0bcc644eed5 upstream.
If a new logical drive is added and the CCISS_REGNEWD ioctl is invoked
(as is normal with the Array Configuration Utility) the process will
hang as below. It attempts to acquire the same mutex twice, once in
do_ioctl() and once in cciss_unlocked_open(). The BKL was recursive,
the mutex isn't.
Linux version 3.10.0-rc2 (scameron@localhost.localdomain) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-3) (GCC) ) #1 SMP Fri May 24 14:32:12 CDT 2013
[...]
acu D 0000000000000001 0 3246 3191 0x00000080
Call Trace:
schedule+0x29/0x70
schedule_preempt_disabled+0xe/0x10
__mutex_lock_slowpath+0x17b/0x220
mutex_lock+0x2b/0x50
cciss_unlocked_open+0x2f/0x110 [cciss]
__blkdev_get+0xd3/0x470
blkdev_get+0x5c/0x1e0
register_disk+0x182/0x1a0
add_disk+0x17c/0x310
cciss_add_disk+0x13a/0x170 [cciss]
cciss_update_drive_info+0x39b/0x480 [cciss]
rebuild_lun_table+0x258/0x370 [cciss]
cciss_ioctl+0x34f/0x470 [cciss]
do_ioctl+0x49/0x70 [cciss]
__blkdev_driver_ioctl+0x28/0x30
blkdev_ioctl+0x200/0x7b0
block_ioctl+0x3c/0x40
do_vfs_ioctl+0x89/0x350
SyS_ioctl+0xa1/0xb0
system_call_fastpath+0x16/0x1b
This mutex usage was added into the ioctl path when the big kernel lock
was removed. As it turns out, these paths are all thread safe anyway
(or can easily be made so) and we don't want ioctl() to be single
threaded in any case.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mike Miller <mike.miller@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 7c689e63a847316c1b2500f86891b0a574ce7e69 upstream.
With an automatic after split-brain recovery policy of
"after-sb-1pri call-pri-lost-after-sb",
when trying to drbd_set_role() to R_SECONDARY,
we run into a deadlock.
This was first recognized and supposedly fixed by
2009-06-10 "Fixed a deadlock when using automatic split brain recovery when both nodes are"
replacing drbd_set_role() with drbd_change_state() in that code-path,
but the first hunk of that patch forgets to remove the drbd_set_role().
We apparently only ever tested the "two primaries" case.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit dfd20b2b174d3a9b258ea3b7a35ead33576587b1 upstream.
The index on the page must be set before it is inserted in the radix
tree. Otherwise there is a small race which can occur during lookup
where the page can be found with the incorrect index. This will trigger
the BUG_ON() in brd_lookup_page().
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reported-by: Chris Wedgwood <cw@f00f.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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[ Upstream commit 91c5746425aed8f7188a351f1224a26aa232e4b3 ]
Some network drivers use a non default hard_header_len
Transmitted skb should take into account dev->hard_header_len, or risk
crashes or expensive reallocations.
In the case of aoe, lets reserve MAX_HEADER bytes.
David reported a crash in defxx driver, solved by this patch.
Reported-by: David Oostdyk <daveo@ll.mit.edu>
Tested-by: David Oostdyk <daveo@ll.mit.edu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ed Cashin <ecashin@coraid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit c1681bf8a7b1b98edee8b862a42c19c4e53205fd upstream.
struct block_device lifecycle is defined by its inode (see fs/block_dev.c) -
block_device allocated first time we access /dev/loopXX and deallocated on
bdev_destroy_inode. When we create the device "losetup /dev/loopXX afile"
we want that block_device stay alive until we destroy the loop device
with "losetup -d".
But because we do not hold /dev/loopXX inode its counter goes 0, and
inode/bdev can be destroyed at any moment. Usually it happens at memory
pressure or when user drops inode cache (like in the test below). When later in
loop_clr_fd() we want to use bdev we have use-after-free error with following
stack:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000280
bd_set_size+0x10/0xa0
loop_clr_fd+0x1f8/0x420 [loop]
lo_ioctl+0x200/0x7e0 [loop]
lo_compat_ioctl+0x47/0xe0 [loop]
compat_blkdev_ioctl+0x341/0x1290
do_filp_open+0x42/0xa0
compat_sys_ioctl+0xc1/0xf20
do_sys_open+0x16e/0x1d0
sysenter_dispatch+0x7/0x1a
To prevent use-after-free we need to grab the device in loop_set_fd()
and put it later in loop_clr_fd().
The issue is reprodusible on current Linus head and v3.3. Here is the test:
dd if=/dev/zero of=loop.file bs=1M count=1
while [ true ]; do
losetup /dev/loop0 loop.file
echo 2 > /proc/sys/vm/drop_caches
losetup -d /dev/loop0
done
[ Doing bdgrab/bput in loop_set_fd/loop_clr_fd is safe, because every
time we call loop_set_fd() we check that loop_device->lo_state is
Lo_unbound and set it to Lo_bound If somebody will try to set_fd again
it will get EBUSY. And if we try to loop_clr_fd() on unbound loop
device we'll get ENXIO.
loop_set_fd/loop_clr_fd (and any other loop ioctl) is called under
loop_device->lo_ctl_mutex. ]
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 0e5e098ac22dae38f957e951b70d3cf73beff0f7 upstream.
Commit 7708992 ("xen/blkback: Seperate the bio allocation and the bio
submission") consolidated the pendcnt updates to just a single write,
neglecting the fact that the error path relied on it getting set to 1
up front (such that the decrement in __end_block_io_op() would actually
drop the count to zero, triggering the necessary cleanup actions).
Also remove a misleading and a stale (after said commit) comment.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit b1a6650406875b9097a032eed89af50682fe1160 upstream.
When loopdev is built as module and we pass an invalid parameter,
loop_init() will return directly without deregister misc device, which
will cause an oops when insert loop module next time because we left some
garbage in the misc device list.
Test case:
sudo modprobe loop max_part=1024
(failed due to invalid parameter)
sudo modprobe loop
(oops)
Clean up nicely to avoid such oops.
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: M. Hindess <hindessm@uk.ibm.com>
Cc: Nikanth Karthikesan <knikanth@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 5370019dc2d2c2ff90e95d181468071362934f3a upstream.
bd_mutex and lo_ctl_mutex can be held in different order.
Path #1:
blkdev_open
blkdev_get
__blkdev_get (hold bd_mutex)
lo_open (hold lo_ctl_mutex)
Path #2:
blkdev_ioctl
lo_ioctl (hold lo_ctl_mutex)
lo_set_capacity (hold bd_mutex)
Lockdep does not report it, because path #2 actually holds a subclass of
lo_ctl_mutex. This subclass seems creep into the code by mistake. The
patch author actually just mentioned it in the changelog, see commit
f028f3b2 ("loop: fix circular locking in loop_clr_fd()"), also see:
http://marc.info/?l=linux-kernel&m=123806169129727&w=2
Path #2 hold bd_mutex to call bd_set_size(), I've protected it
with i_mutex in a previous patch, so drop bd_mutex at this site.
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: M. Hindess <hindessm@uk.ibm.com>
Cc: Nikanth Karthikesan <knikanth@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 3a2d63f87989e01437ba994df5f297528c353d7d upstream.
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2:
- Adjusted context
- s/\bnbd\b/lo/
- Incorporate export of kill_bdev() from commit ff01bb483265
('fs: move code out of buffer.c')]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 9d092603cc306ee6edfe917bf9ab8beb5f32d7bc upstream.
"be->mode" is obtained from xenbus_read(), which does a kmalloc() for
the message body. The short string is never released, so do it along
with freeing "be" itself, and make sure the string isn't kept when
backend_changed() doesn't complete successfully (which made it
desirable to slightly re-structure that function, so that the error
cleanup can be done in one place).
Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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[ Upstream commit f4d9605434c0fd4cc8639bf25cfc043418c52362 ]
The 'operations' bitmap corresponds one-for-one with the operation
codes, no adjustment is necessary.
Reported-by: Mark Kettenis <mark.kettenis@xs4all.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 72585d2428fa3a0daab02ebad1f41e5ef517dbaa upstream.
Without this, iostat frequently sees bogus svctime and >= 100% "utilization".
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit f4953fe6c4aeada2d5cafd78aa97587a46d2d8f9 upstream.
When a file system is mounted on a virtio-blk disk, we then remove it
and then reattach it, the reattached disk gets the same disk name and
ids as the hot removed one.
This leads to very nasty effects - mostly rendering the newly attached
device completely unusable.
Trying what happens when I do the same thing with a USB device, I saw
that the sd node simply doesn't get free'd when a device gets forcefully
removed.
Imitate the same behavior for vd devices. This way broken vd devices
simply are never free'd and newly attached ones keep working just fine.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 0a41409c518083133e79015092585d68915865be upstream.
blk_alloc_queue has already done a bdi_init, so do not bdi_init
again in aoeblk_gdalloc. The extra call causes list corruption
in the per-CPU backing dev info stats lists.
Affected users see console WARNINGs about list_del corruption on
percpu_counter_destroy when doing "rmmod aoe" or "aoeflush -a"
when AoE targets have been detected and initialized by the
system.
The patch below applies to v3.6.11, with its v47 aoe driver. It
is expected to apply to all currently maintained stable kernels
except 3.7.y. A related but different fix has been posted for
3.7.y.
References:
RedHat bugzilla ticket with original report
https://bugzilla.redhat.com/show_bug.cgi?id=853064
LKML discussion of bug and fix
http://thread.gmane.org/gmane.linux.kernel/1416336/focus=1416497
Reported-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit d60e7ec18c3fb2cbf90969ccd42889eb2d03aef9 upstream.
On floppy initialization, if something failed inside the loop we call
add_disk, there was no cleanup of previous iterations in the error
handling.
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 238ab78469c6ab7845b43d5061cd3c92331b2452 upstream.
If blk_init_queue fails, we do not call put_disk on the current dr
(dr is decremented first in the error handling loop).
Reviewed-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit f6365201d8a21fb347260f89d6e9b3e718d63c70 upstream.
The X86_32-only disable_hlt/enable_hlt mechanism was used by the
32-bit floppy driver. Its effect was to replace the use of the
HLT instruction inside default_idle() with cpu_relax() - essentially
it turned off the use of HLT.
This workaround was commented in the code as:
"disable hlt during certain critical i/o operations"
"This halt magic was a workaround for ancient floppy DMA
wreckage. It should be safe to remove."
H. Peter Anvin additionally adds:
"To the best of my knowledge, no-hlt only existed because of
flaky power distributions on 386/486 systems which were sold to
run DOS. Since DOS did no power management of any kind,
including HLT, the power draw was fairly uniform; when exposed
to the much hhigher noise levels you got when Linux used HLT
caused some of these systems to fail.
They were by far in the minority even back then."
Alan Cox further says:
"Also for the Cyrix 5510 which tended to go castors up if a HLT
occurred during a DMA cycle and on a few other boxes HLT during
DMA tended to go astray.
Do we care ? I doubt it. The 5510 was pretty obscure, the 5520
fixed it, the 5530 is probably the oldest still in any kind of
use."
So, let's finally drop this.
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Stephen Hemminger <shemminger@vyatta.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-3rhk9bzf0x9rljkv488tloib@git.kernel.org
[ If anyone cares then alternative instruction patching could be
used to replace HLT with a one-byte NOP instruction. Much simpler. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.2: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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[ Upstream commit 8babe8cc6570ed896b7b596337eb8fe730c3ff45 ]
In order for the network layer to see that AoE requires
no checksumming in a generic way, the packets must be
marked as requiring no checksum, so we make this requirement
explicit with the assertion.
Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 2453f5f992717251cfadab6184fbb3ec2f2e8b40 upstream.
If a command completes with a status of CMD_PROTOCOL_ERR, this
information should be conveyed to the SCSI mid layer, not dropped
on the floor. Unlike a similar bug in the hpsa driver, this bug
only affects tape drives and CD and DVD ROM drives in the cciss
driver, and to induce it, you have to disconnect (or damage) a
cable, so it is not a very likely scenario (which would explain
why the bug has gone undetected for the last 10 years.)
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit fded4e090c60100d709318896c79816d68d5b47d upstream.
Fix a serious but uncommon bug in nbd which occurs when there is heavy
I/O going to the nbd device while, at the same time, a failure (server,
network) or manual disconnect of the nbd connection occurs.
There is a small window between the time that the nbd_thread is stopped
and the socket is shutdown where requests can continue to be queued to
nbd's internal waiting_queue. When this happens, those requests are
never completed or freed.
The fix is to clear the waiting_queue on shutdown of the nbd device, in
the same way that the nbd request queue (queue_head) is already being
cleared.
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>
[bwh: Backported to 3.2: local nbd_device pointers are called 'lo' not 'nbd']
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 483001c765af6892b3fc3726576cb42f17d1d6b5 upstream.
blk_cleanup_queue() will call blk_drian_queue() to drain all the
requests before queue DEAD marking. If we reset the device before
blk_cleanup_queue() the drain would fail.
1) if the queue is stopped in do_virtblk_request() because device is
full, the q->request_fn() will not be called.
blk_drain_queue() {
while(true) {
...
if (!list_empty(&q->queue_head))
__blk_run_queue(q) {
if (queue is not stoped)
q->request_fn()
}
...
}
}
Do no reset the device before blk_cleanup_queue() gives the chance to
start the queue in interrupt handler blk_done().
2) In commit b79d866c8b7014a51f611a64c40546109beaf24a, We abort requests
dispatched to driver before blk_cleanup_queue(). There is a race if
requests are dispatched to driver after the abort and before the queue
DEAD mark. To fix this, instead of aborting the requests explicitly, we
can just reset the device after after blk_cleanup_queue so that the
device can complete all the requests before queue DEAD marking in the
drain process.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 02e2b124943648fba0a2ccee5c3656a5653e0151 upstream.
del_gendisk() might not return due to failing to remove the
/sys/block/vda/serial sysfs entry when another thread (udev) is
trying to read it.
virtblk_remove()
vdev->config->reset() : guest will not kick us through interrupt
del_gendisk()
device_del()
kobject_del(): got stuck, sysfs entry ref count non zero
sysfs_open_file(): user space process read /sys/block/vda/serial
sysfs_get_active() : got sysfs entry ref count
dev_attr_show()
virtblk_serial_show()
blk_execute_rq() : got stuck, interrupt is disabled
request cannot be finished
This patch fixes it by calling del_gendisk() before we disable guest's
interrupt so that the request sent in virtblk_serial_show() will be
finished and del_gendisk() will success.
This fixes another race in hot-unplug process.
It is save to call del_gendisk(vblk->disk) before
flush_work(&vblk->config_work) which might access vblk->disk, because
vblk->disk is not freed until put_disk(vblk->disk).
Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit b79d866c8b7014a51f611a64c40546109beaf24a upstream.
If we reset the virtio-blk device before the requests already dispatched
to the virtio-blk driver from the block layer are finised, we will stuck
in blk_cleanup_queue() and the remove will fail.
blk_cleanup_queue() calls blk_drain_queue() to drain all requests queued
before DEAD marking. However it will never success if the device is
already stopped. We'll have q->in_flight[] > 0, so the drain will not
finish.
How to reproduce the race:
1. hot-plug a virtio-blk device
2. keep reading/writing the device in guest
3. hot-unplug while the device is busy serving I/O
Test:
~1000 rounds of hot-plug/hot-unplug test passed with this patch.
Changes in v3:
- Drop blk_abort_queue and blk_abort_request
- Use __blk_end_request_all to complete request dispatched to driver
Changes in v2:
- Drop req_in_flight
- Use virtqueue_detach_unused_buf to get request dispatched to driver
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit f65ca1dc6a8c81c6bd72297d4399ec5f4c1f3a01 upstream.
Benchmark shows small performance improvement on fusion io device.
Before:
seq-read : io=1,024MB, bw=19,982KB/s, iops=39,964, runt= 52475msec
seq-write: io=1,024MB, bw=20,321KB/s, iops=40,641, runt= 51601msec
rnd-read : io=1,024MB, bw=15,404KB/s, iops=30,808, runt= 68070msec
rnd-write: io=1,024MB, bw=14,776KB/s, iops=29,552, runt= 70963msec
After:
seq-read : io=1,024MB, bw=20,343KB/s, iops=40,685, runt= 51546msec
seq-write: io=1,024MB, bw=20,803KB/s, iops=41,606, runt= 50404msec
rnd-read : io=1,024MB, bw=16,221KB/s, iops=32,442, runt= 64642msec
rnd-write: io=1,024MB, bw=15,199KB/s, iops=30,397, runt= 68991msec
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 4678d6f970c2f7c0cbfefc0cc666432d153b321b upstream.
Fix a theoretical race related to config work
handler: a config interrupt might happen
after we flush config work but before we
reset the device. It will then cause the
config work to run during or after reset.
Two problems with this:
- if this runs after device is gone we will get use after free
- access of config while reset is in progress is racy
(as layout is changing).
As a solution
1. flush after reset when we know there will be no more interrupts
2. add a flag to disable config access before reset
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit b0cf0b118c90477d1a6811f2cd2307f6a5578362 upstream.
Delete code which sets SCSI status incorrectly as it's already been set
correctly above this incorrect code. The bug was introduced in 2009 by
commit b0e15f6db111 ("cciss: fix typo that causes scsi status to be
lost.")
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reported-by: Roel van Meer <roel.vanmeer@bokxing.nl>
Tested-by: Roel van Meer <roel.vanmeer@bokxing.nl>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 2c95a3290919541b846bee3e0fbaa75860929f53 upstream.
Block layer will allocate a spinlock for the queue if the driver does
not provide one in blk_init_queue().
The reason to use the internal spinlock is that blk_cleanup_queue() will
switch to use the internal spinlock in the cleanup code path.
if (q->queue_lock != &q->__queue_lock)
q->queue_lock = &q->__queue_lock;
However, processes which are in D state might have taken the driver
provided spinlock, when the processes wake up, they would release the
block provided spinlock.
=====================================
[ BUG: bad unlock balance detected! ]
3.4.0-rc7+ #238 Not tainted
-------------------------------------
fio/3587 is trying to release lock (&(&q->__queue_lock)->rlock) at:
[<ffffffff813274d2>] blk_queue_bio+0x2a2/0x380
but there are no more locks to release!
other info that might help us debug this:
1 lock held by fio/3587:
#0: (&(&vblk->lock)->rlock){......}, at:
[<ffffffff8132661a>] get_request_wait+0x19a/0x250
Other drivers use block layer provided spinlock as well, e.g. SCSI.
Switching to the block layer provided spinlock saves a bit of memory and
does not increase lock contention. Performance test shows no real
difference is observed before and after this patch.
Changes in v2: Improve commit log as Michael suggested.
Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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called
commit 3f9a5aabd0a9fe0e0cd308506f48963d79169aa7 upstream.
add_disk() takes gendisk reference on request queue. If driver failed during
initialization and never called add_disk() then that extra reference is not
taken. That reference is put in put_disk(). floppy driver allocates the
disk, allocates queue, sets disk->queue and then relizes that floppy
controller is not present. It tries to tear down everything and tries to
put a reference down in put_disk() which was never taken.
In such error cases cleanup disk->queue before calling put_disk() so that
we never try to put down a reference which was never taken in first place.
Reported-and-tested-by: Suresh Jayaraman <sjayaraman@suse.com>
Tested-by: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 32587371ad3db2f9d335de10dbd8cffd4fff5669 upstream.
Fix a regression introduced by 7eaceaccab5f40 ("block: remove per-queue
plugging"). In that patch, Jens removed the whole mm_unplug_device()
function, which used to be the trigger to make umem start to work.
We need to implement unplugging to make umem start to work, or I/O will
never be triggered.
Signed-off-by: Tao Guo <Tao.Guo@emc.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Shaohua Li <shli@kernel.org>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit bc67f63650fad6b3478d9ddfd5406d45a95987c9 upstream.
The total number of scatter gather elements in the CISS command
used by the scsi tape code was being cast to a u8, which can hold
at most 255 scatter gather elements. It should have been cast to
a u16. Without this patch the command gets rejected by the controller
since the total scatter gather count did not add up to the right
value resulting in an i/o error.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 395d287526bb60411ff37b19ad9dd38b58ba8732 upstream.
The default is too small (1024 blocks), use h->cciss_max_sectors (8192 blocks)
Without this change, if you try to set the block size of a tape drive above
512*1024, via "mt -f /dev/st0 setblk nnn" where nnn is greater than 524288,
it won't work right.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ea5f4db8ece896c2ab9eafa0924148a2596c52e4 upstream.
"mem" is type u8. We need parenthesis here or it screws up the pointer
math probably leading to an oops.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 577ebb374c78314ac4617242f509e2f5e7156649 upstream.
Introduce a wrapper around scsi_cmd_ioctl that takes a block device.
The function will then be enhanced to detect partition block devices
and, in that case, subject the ioctls to whitelisting.
Cc: linux-scsi@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: James Bottomley <JBottomley@parallels.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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* 'for-linus' of git://git.kernel.dk/linux-block:
block: don't kick empty queue in blk_drain_queue()
block/swim3: Locking fixes
loop: Fix discard_alignment default setting
cfq-iosched: fix cfq_cic_link() race confition
cfq-iosched: free cic_index if blkio_alloc_blkg_stats fails
cciss: fix flush cache transfer length
cciss: Add IRQF_SHARED back in for the non-MSI(X) interrupt handler
loop: fix loop block driver discard and encryption comment
block: initialize request_queue's numa node during
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git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: add missing spin_unlock at ceph_mdsc_build_path()
ceph: fix SEEK_CUR, SEEK_SET regression
crush: fix mapping calculation when force argument doesn't exist
ceph: use i_ceph_lock instead of i_lock
rbd: remove buggy rollback functionality
rbd: return an error when an invalid header is read
ceph: fix rasize reporting by ceph_show_options
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The old PowerMac swim3 driver has some "interesting" locking issues,
using a private lock and failing to lock the queue before completing
requests, which triggered WARN_ONs among others.
This rips out the private lock, makes everything operate under the
block queue lock, and generally makes things simpler.
We used to also share a queue between the two possible instances which
was problematic since we might pick the wrong controller in some cases,
so make the queue and the current request per-instance and use
queuedata to point to our private data which is a lot cleaner.
We still share the queue lock but then, it's nearly impossible to actually
use 2 swim3's simultaneously: one would need to have a Wallstreet
PowerBook, the only machine afaik with two of these on the motherboard,
and populate both hotswap bays with a floppy drive (the machine ships
only with one), so nobody cares...
While at it, add a little fix to clear up stale interrupts when loading
the driver or plugging a floppy drive in a bay.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This doesn't interact with resizing well, since it doesn't set the
size of the device to the size at the snapshot. It's also an expensive
operation to be synchronous. Rollback can still be done with the
userspace rbd tool.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
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This protects against opening future rbd images that have incompatible format changes.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
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discard_alignment is not relevant to the loop driver since it is
supposed to be set as a workaround for the old sector 63 alignments.
So set it to zero rather than block size.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reported-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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We weren't filling in the transfer length of the
flush cache command (it transfers 4 bytes of zeroes).
Firmware didn't seem to be bothered by this, but it
should be fixed.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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IRQF_SHARED is required for older controllers that don't support MSI(X)
and which may end up sharing an interrupt.
Also remove deprecated IRQF_DISABLED.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The loop driver does not support discard if encryption is enabled,
fix the comment.
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Smatch has a new check for Rosenberg type information leaks where structs
are copied to the user with uninitialized stack data in them. i In this
case, the pg_write_hdr struct has a hole in it.
struct pg_write_hdr {
char magic; /* 0 1 */
char func; /* 1 1 */
/* XXX 2 bytes hole, try to pack */
int dlen; /* 4 4 */
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Tim Waugh <tim@cyberelk.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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A long time ago, probably in 2002, one of the distros, or maybe more than
one, loaded block drivers prior to loading the SCSI mid layer. This meant
that the cciss driver, being a block driver, could not engage the SCSI mid
layer at init time without panicking, and relied on being poked by a
userland program after the system was up (and the SCSI mid layer was
therefore present) to engage the SCSI mid layer.
This is no longer the case, and cciss can safely rely on the SCSI mid
layer being present at init time and engage the SCSI mid layer straight
away. This means that users will see their tape drives and medium
changers at driver load time without need for a script in /etc/rc.d that
does this:
for x in /proc/driver/cciss/cciss*
do
echo "engage scsi" > $x
done
However, if no tape drives or medium changers are detected, the SCSI mid
layer will not be engaged. If a tape drive or medium change is later
hot-added to the system it will then be necessary to use the above script
or similar for the device(s) to be acceesible.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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1) Anyone who has read access to loopdev has permission to call set_status
and may change important parameters such as lo_offset, lo_sizelimit and
so on, which contradicts to read access pattern and definitely equals
to write access pattern.
2) Add lo_offset over i_size check to prevent blkdev_size overflow.
##Testcase_bagin
#dd if=/dev/zero of=./file bs=1k count=1
#losetup /dev/loop0 ./file
/* userspace_application */
struct loop_info64 loinf;
fd = open("/dev/loop0", O_RDONLY);
ioctl(fd, LOOP_GET_STATUS64, &loinf);
/* Set offset to any value which is bigger than i_size, and sizelimit
* to nonzero value*/
loinf.lo_offset = 4096*1024;
loinf.lo_sizelimit = 1024;
ioctl(fd, LOOP_SET_STATUS64, &loinf);
/* After this loop device will have size similar to 0x7fffffffffxxxx */
#blockdev --getsz /dev/loop0
##OUTPUT: 36028797018955968
##Testcase_end
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If read was not fully successful we have to fail whole bio to prevent
information leak of old pages
##Testcase_begin
dd if=/dev/zero of=./file bs=1M count=1
losetup /dev/loop0 ./file -o 4096
truncate -s 0 ./file
# OOps loop offset is now beyond i_size, so read will silently fail.
# So bio's pages would not be cleared, may which result in information leak.
hexdump -C /dev/loop0
##testcase_end
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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