Because of the peculiar way that md devices are created (automatically
when the device node is opened), a new device can be created and
registered immediately after the
blk_unregister_region(disk_devt(disk), disk->minors);
call in del_gendisk().
Therefore it is important that all visible artifacts of the previous
device are removed before this call. In particular, the 'bdi'.
Since:
commit c4db59d31e
Author: Christoph Hellwig <hch@lst.de>
fs: don't reassign dirty inodes to default_backing_dev_info
moved the
device_unregister(bdi->dev);
call from bdi_unregister() to bdi_destroy() it has been quite easy to
lose a race and have a new (e.g.) "md127" be created after the
blk_unregister_region() call and before bdi_destroy() is ultimately
called by the final 'put_disk', which must come after del_gendisk().
The new device finds that the bdi name is already registered in sysfs
and complains
> [ 9627.630029] WARNING: CPU: 18 PID: 3330 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x5a/0x70()
> [ 9627.630032] sysfs: cannot create duplicate filename '/devices/virtual/bdi/9:127'
We can fix this by moving the bdi_destroy() call out of
blk_release_queue() (which can happen very late when a refcount
reaches zero) and into blk_cleanup_queue() - which happens exactly when the md
device driver calls it.
Then it is only necessary for md to call blk_cleanup_queue() before
del_gendisk(). As loop.c devices are also created on demand by
opening the device node, we make the same change there.
Fixes: c4db59d31e
Reported-by: Azat Khuzhin <a3at.mail@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org (v4.0)
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Looks like we pull it in through other ways on x86, but we fail
on sparc:
In file included from drivers/block/cryptoloop.c:30:0:
drivers/block/loop.h:63:24: error: field 'tag_set' has incomplete type
struct blk_mq_tag_set tag_set;
Add the include to loop.h, kill it from loop.c.
Signed-off-by: Jens Axboe <axboe@fb.com>
block core handles REQ_FUA by its flush state machine, so
won't do it in loop explicitly.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
No behaviour change, just move the handling for REQ_DISCARD
and REQ_FLUSH in these two functions.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The conversion is a bit straightforward, and use work queue to
dispatch requests of loop block, and one big change is that requests
is submitted to backend file/device concurrently with work queue,
so throughput may get improved much. Given write requests over same
file are often run exclusively, so don't handle them concurrently for
avoiding extra context switch cost, possible lock contention and work
schedule cost. Also with blk-mq, there is opportunity to get loop I/O
merged before submitting to backend file/device.
In the following test:
- base: v3.19-rc2-2041231
- loop over file in ext4 file system on SSD disk
- bs: 4k, libaio, io depth: 64, O_DIRECT, num of jobs: 1
- throughput: IOPS
------------------------------------------------------
| | base | base with loop-mq | delta |
------------------------------------------------------
| randread | 1740 | 25318 | +1355%|
------------------------------------------------------
| read | 42196 | 51771 | +22.6%|
-----------------------------------------------------
| randwrite | 35709 | 34624 | -3% |
-----------------------------------------------------
| write | 39137 | 40326 | +3% |
-----------------------------------------------------
So loop-mq can improve throughput for both read and randread, meantime,
performance of write and randwrite isn't hurted basically.
Another benefit is that loop driver code gets simplified
much after blk-mq conversion, and the patch can be thought as
cleanup too.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Discard requests are ignored if the encryption is enabled for the given
loop device. Update comment to match the code, and similar comments
elsewhere in the file.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull VFS updates from Al Viro,
Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).
7kloc removed.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
don't bother with deferred freeing of fdtables
proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
proc: Make the PROC_I() and PDE() macros internal to procfs
proc: Supply a function to remove a proc entry by PDE
take cgroup_open() and cpuset_open() to fs/proc/base.c
ppc: Clean up scanlog
ppc: Clean up rtas_flash driver somewhat
hostap: proc: Use remove_proc_subtree()
drm: proc: Use remove_proc_subtree()
drm: proc: Use minor->index to label things, not PDE->name
drm: Constify drm_proc_list[]
zoran: Don't print proc_dir_entry data in debug
reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
proc: Supply an accessor for getting the data from a PDE's parent
airo: Use remove_proc_subtree()
rtl8192u: Don't need to save device proc dir PDE
rtl8187se: Use a dir under /proc/net/r8180/
proc: Add proc_mkdir_data()
proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
proc: Move PDE_NET() to fs/proc/proc_net.c
...
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Merge tag 'for-linus-20130409' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"I've got a few smaller fixes queued up for 3.9 that should go in. The
major one is the loop regression, the others are nice fixes on their
own though. It contains:
- Fix for unitialized var in the block sysfs code, courtesy of Arnd
and gcc-4.8.
- Two fixes for mtip32xx, fixing probe and command timeout. Also a
debug measure that could have waited for 3.10, but it's driver
only, so I let it slip in.
- Revert the loop partition cleanup fix, it could cause a deadlock on
auto-teardown as part of umount. The fix is clear, but at this
point we just want to revert it and get a real fix in for 3.10."
* tag 'for-linus-20130409' of git://git.kernel.dk/linux-block:
Revert "loop: cleanup partitions when detaching loop device"
mtip32xx: fix two smatch warnings
mtip32xx: Add debugfs entry device_status
mtip32xx: return 0 from pci probe in case of rebuild
mtip32xx: recovery from command timeout
block: avoid using uninitialized value in from queue_var_store
This reverts commit 8761a3dc1f.
There are situations where the destruction path is called
with the bdev->bd_mutex already held, which then deadlocks in
loop_clr_fd(). The normal partition cleanup does a trylock()
on the mutex, but it'd be nice to have a more bullet proof
method in loop. So punt this more involved fix to the next
merge window, and just back out this buggy fix for now.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Any partitions added by user space to the loop device were being
left in place after detaching the loop device. This was because
the detach path issued a BLKRRPART to clean up partitions if
LO_FLAGS_PARTSCAN was set, meaning that the partitions were auto
scanned on attach. Replace this BLKRRPART with code that
unconditionally cleans up partitions on detach instead.
Signed-off-by: Phillip Susi <psusi@ubuntu.com>
Modified by Jens to export delete_partition().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fix to return a negative error code from the error handling
case, as returned elsewhere in this function.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block driver bits from Jens Axboe:
"After the block IO core bits are in, please grab the driver updates
from below as well. It contains:
- Fix ancient regression in dac960. Nobody must be using that
anymore...
- Some good fixes from Guo Ghao for loop, fixing both potential
oopses and deadlocks.
- Improve mtip32xx for NUMA systems, by being a bit more clever in
distributing work.
- Add IBM RamSan 70/80 driver. A second round of fixes for that is
pending, that will come in through for-linus during the 3.9 cycle
as per usual.
- A few xen-blk{back,front} fixes from Konrad and Roger.
- Other minor fixes and improvements."
* 'for-3.9/drivers' of git://git.kernel.dk/linux-block:
loopdev: ignore negative offset when calculate loop device size
loopdev: remove an user triggerable oops
loopdev: move common code into loop_figure_size()
loopdev: update block device size in loop_set_status()
loopdev: fix a deadlock
xen-blkback: use balloon pages for persistent grants
xen-blkfront: drop the use of llist_for_each_entry_safe
xen/blkback: Don't trust the handle from the frontend.
xen-blkback: do not leak mode property
block: IBM RamSan 70/80 driver fixes
rsxx: add slab.h include to dma.c
drivers/block/mtip32xx: add missing GENERIC_HARDIRQS dependency
block: remove new __devinit/exit annotations on ramsam driver
block: IBM RamSan 70/80 device driver
drivers/block/mtip32xx/mtip32xx.c:1726:5: sparse: symbol 'mtip_send_trim' was not declared. Should it be static?
drivers/block/mtip32xx/mtip32xx.c:4029:1: sparse: symbol 'mtip_workq_sdbf0' was not declared. Should it be static?
dac960: return success instead of -ENOTTY
mtip32xx: add trim support
mtip32xx: Add workqueue and NUMA support
block: delete super ancient PC-XT driver for 1980's hardware
Convert to the much saner new idr interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated. Drop its usage.
Signed-off-by: Tejun Heo <tj@kernel.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>
Negative offset may cause loop device size larger than backing file
size.
$ fallocate -l 1M a
$ losetup --offset 0xffffffffffff0000 /dev/loop0 a
$ blockdev --getsize64 /dev/loop0
1114112
$ ls -l a
-rw-r--r-- 1 root root 1048576 Jan 23 12:46 a
$ cat /dev/loop0
cat: /dev/loop0: Input/output error
It makes no sense to do that. Only apply offset when it's positive.
Fix a typo in the comment by the way.
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>
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>
Update block device size in accord with gendisk size and let userspace
know the change in loop_figure_size(). This is a clean up to remove
common code of loop_figure_size()'s two callers.
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>
Loop device driver sometimes fails to impose the size limit on the
device. Keep issuing following two commands:
losetup --offset 7517244416 --sizelimit 3224971264 /dev/loop0 backed_file
blockdev --getsize64 /dev/loop0
blockdev reports file size instead of sizelimit several out of 100 times.
The problems are:
- losetup set up the device in two ioctl:
LOOP_SET_FD and LOOP_SET_STATUS64.
- LOOP_SET_STATUS64 only update size of gendisk.
Block device size will be updated lazily when device comes to use. If udev
rushes in between the two ioctl, it will bring in a block device whose
size is backing file size. If the device is not released after
LOOP_SET_STATUS64 ioctl, blockdev will not see the updated size.
Update block size in LOOP_SET_STATUS64 ioctl.
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Reported-by: M. Hindess <hindessm@uk.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guo Chao <yan@linux.vnet.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>
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>
Pull block driver update from Jens Axboe:
"Now that the core bits are in, here are the driver bits for 3.8. The
branch contains:
- A huge pile of drbd bits that were dumped from the 3.7 merge
window. Following that, it was both made perfectly clear that
there is going to be no more over-the-wall pulls and how the
situation on individual pulls can be improved.
- A few cleanups from Akinobu Mita for drbd and cciss.
- Queue improvement for loop from Lukas. This grew into adding a
generic interface for waiting/checking an even with a specific
lock, allowing this to be pulled out of md and now loop and drbd is
also using it.
- A few fixes for xen back/front block driver from Roger Pau Monne.
- Partition improvements from Stephen Warren, allowing partiion UUID
to be used as an identifier."
* 'for-3.8/drivers' of git://git.kernel.dk/linux-block: (609 commits)
drbd: update Kconfig to match current dependencies
drbd: Fix drbdsetup wait-connect, wait-sync etc... commands
drbd: close race between drbd_set_role and drbd_connect
drbd: respect no-md-barriers setting also when changed online via disk-options
drbd: Remove obsolete check
drbd: fixup after wait_even_lock_irq() addition to generic code
loop: Limit the number of requests in the bio list
wait: add wait_event_lock_irq() interface
xen-blkfront: free allocated page
xen-blkback: move free persistent grants code
block: partition: msdos: provide UUIDs for partitions
init: reduce PARTUUID min length to 1 from 36
block: store partition_meta_info.uuid as a string
cciss: use check_signature()
cciss: cleanup bitops usage
drbd: use copy_highpage
drbd: if the replication link breaks during handshake, keep retrying
drbd: check return of kmalloc in receive_uuids
drbd: Broadcast sync progress no more often than once per second
drbd: don't try to clear bits once the disk has failed
...
Currently there is not limitation of number of requests in the loop bio
list. This can lead into some nasty situations when the caller spawns
tons of bio requests taking huge amount of memory. This is even more
obvious with discard where blkdev_issue_discard() will submit all bios
for the range and wait for them to finish afterwards. On really big loop
devices and slow backing file system this can lead to OOM situation as
reported by Dave Chinner.
With this patch we will wait in loop_make_request() if the number of
bios in the loop bio list would exceed 'nr_congestion_on'.
We'll wake up the process as we process the bios form the list. Some
threshold hysteresis is in place to avoid high frequency oscillation.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reported-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
xfstests has always had random failures of tests due to loop devices
failing to be torn down and hence leaving filesytems that cannot be
unmounted. This causes test runs to immediately stop.
Over the past 6 or 7 years we've added hacks like explicit unmount
-d commands for loop mounts, losetup -d after unmount -d fails, etc,
but still the problems persist. Recently, the frequency of loop
related failures increased again to the point that xfstests 259 will
reliably fail with a stray loop device that was not torn down.
That is despite the fact the test is above as simple as it gets -
loop 5 or 6 times running mkfs.xfs with different paramters:
lofile=$(losetup -f)
losetup $lofile "$testfile"
"$MKFS_XFS_PROG" -b size=512 $lofile >/dev/null || echo "mkfs failed!"
sync
losetup -d $lofile
And losteup -d $lofile is failing with EBUSY on 1-3 of these loops
every time the test is run.
Turns out that blkid is running simultaneously with losetup -d, and
so it sees an elevated reference count and returns EBUSY. But why
is blkid running? It's obvious, isn't it? udev has decided to try
and find out what is on the block device as a result of a creation
notification. And it is racing with mkfs, so might still be scanning
the device when mkfs finishes and we try to tear it down.
So, make losetup -d force autoremove behaviour. That is, when the
last reference goes away, tear down the device. xfstests wants it
*gone*, not causing random teardown failures when we know that all
the operations the tests have specifically run on the device have
completed and are no longer referencing the loop device.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The idr_pre_get() function never returns a value < 0. It returns 0 (no
memory) or 1 (OK).
Reported-by: Silva Paulo <psdasilva@yahoo.com>
[ Rewrote Silva's patch, but attributing it to Silva anyway - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 8268f5a741 ("deny partial write for loop dev fd") tried to fix the
loop device partial read information leak problem. But it changed the
semantics of read behavior. When we read beyond the end of the device we
should get 0 bytes, which is normal behavior, we should not just return
-EIO
Instead of returning -EIO, zero out the bio to avoid information leak in
case of partail read.
Signed-off-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Tested-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Dmitry Monakhov <dmonakhov@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export
kill_bdev as well, so brd doesn't have to open code it. Reduce
buffer_head.h requirement accordingly.
Removed a rather large comment from invalidate_bdev, as it looked a bit
obsolete to bother moving. The small comment replacing it says enough.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
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>
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>
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>
* 'for-3.2/drivers' of git://git.kernel.dk/linux-block: (30 commits)
virtio-blk: use ida to allocate disk index
hpsa: add small delay when using PCI Power Management to reset for kump
cciss: add small delay when using PCI Power Management to reset for kump
xen/blkback: Fix two races in the handling of barrier requests.
xen/blkback: Check for proper operation.
xen/blkback: Fix the inhibition to map pages when discarding sector ranges.
xen/blkback: Report VBD_WSECT (wr_sect) properly.
xen/blkback: Support 'feature-barrier' aka old-style BARRIER requests.
xen-blkfront: plug device number leak in xlblk_init() error path
xen-blkfront: If no barrier or flush is supported, use invalid operation.
xen-blkback: use kzalloc() in favor of kmalloc()+memset()
xen-blkback: fixed indentation and comments
xen-blkfront: fix a deadlock while handling discard response
xen-blkfront: Handle discard requests.
xen-blkback: Implement discard requests ('feature-discard')
xen-blkfront: add BLKIF_OP_DISCARD and discard request struct
drivers/block/loop.c: remove unnecessary bdev argument from loop_clr_fd()
drivers/block/loop.c: emit uevent on auto release
drivers/block/cpqarray.c: use pci_dev->revision
loop: always allow userspace partitions and optionally support automatic scanning
...
Fic up trivial header file includsion conflict in drivers/block/loop.c
