[ Upstream commit bb430b6942 ]
LOOP_CONFIGURE is, as far as I understand it, supposed to be a way to
combine LOOP_SET_FD and LOOP_SET_STATUS64 into a single syscall. When
using LOOP_SET_FD+LOOP_SET_STATUS64, a single uevent would be sent for
each partition found on the loop device after the second ioctl(), but
when using LOOP_CONFIGURE, no such uevent was being sent.
In the old setup, uevents are disabled for LOOP_SET_FD, but not for
LOOP_SET_STATUS64. This makes sense, as it prevents uevents being
sent for a partially configured device during LOOP_SET_FD - they're
only sent at the end of LOOP_SET_STATUS64. But for LOOP_CONFIGURE,
uevents were disabled for the entire operation, so that final
notification was never issued. To fix this, reduce the critical
section to exclude the loop_reread_partitions() call, which causes
the uevents to be issued, to after uevents are re-enabled, matching
the behaviour of the LOOP_SET_FD+LOOP_SET_STATUS64 combination.
I noticed this because Busybox's losetup program recently changed from
using LOOP_SET_FD+LOOP_SET_STATUS64 to LOOP_CONFIGURE, and this broke
my setup, for which I want a notification from the kernel any time a
new partition becomes available.
Signed-off-by: Alyssa Ross <hi@alyssa.is>
[hch: reduced the critical section]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: 3448914e8c ("loop: Add LOOP_CONFIGURE ioctl")
Link: https://lore.kernel.org/r/20230320125430.55367-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 498ef5c777 ]
Currently, udev change event is generated for a loop device before the
device is ready for IO. Due to serialization on lo->lo_mutex in
lo_open() this does not matter because anybody is able to open the
device and do IO only after the configuration is finished. However this
synchronization in lo_open() is going away so make sure userspace
reacting to the change event will see the new device state by generating
the event only when the device is setup.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220330052917.2566582-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: bb430b6942 ("loop: LOOP_CONFIGURE: send uevents for partitions")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9b0cb770f5 ]
do_req_filebacked() calls blk_mq_complete_request() synchronously or
asynchronously when using asynchronous I/O unless memory allocation fails.
Hence, modify loop_handle_cmd() such that it does not dereference 'cmd' nor
'rq' after do_req_filebacked() finished unless we are sure that the request
has not yet been completed. This patch fixes the following kernel crash:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000054
Call trace:
css_put.42938+0x1c/0x1ac
loop_process_work+0xc8c/0xfd4
loop_rootcg_workfn+0x24/0x34
process_one_work+0x244/0x558
worker_thread+0x400/0x8fc
kthread+0x16c/0x1e0
ret_from_fork+0x10/0x20
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Schatzberg <schatzberg.dan@gmail.com>
Fixes: c74d40e8b5 ("loop: charge i/o to mem and blk cg")
Fixes: bc07c10a36 ("block: loop: support DIO & AIO")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230314182155.80625-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9f6ad5d533 ]
In loop_set_status_from_info(), lo->lo_offset and lo->lo_sizelimit should
be checked before reassignment, because if an overflow error occurs, the
original correct value will be changed to the wrong value, and it will not
be changed back.
More, the original patch did not solve the problem, the value was set and
ioctl returned an error, but the subsequent io used the value in the loop
driver, which still caused an alarm:
loop_handle_cmd
do_req_filebacked
loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;
lo_rw_aio
cmd->iocb.ki_pos = pos
Fixes: c490a0b5a4 ("loop: Check for overflow while configuring loop")
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230221095027.3656193-1-zhongjinghua@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 85c5019771 upstream.
Currently, the max_loop commandline argument can be used to specify how
many loop block devices are created at init time. If it is not
specified on the commandline, CONFIG_BLK_DEV_LOOP_MIN_COUNT loop block
devices will be created.
The max_loop commandline argument can be used to override the value of
CONFIG_BLK_DEV_LOOP_MIN_COUNT. However, when max_loop is set to 0
through the commandline, the current logic treats it as if it had not
been set, and creates CONFIG_BLK_DEV_LOOP_MIN_COUNT devices anyway.
Fix this by starting max_loop off as set to CONFIG_BLK_DEV_LOOP_MIN_COUNT.
This preserves the intended behavior of creating
CONFIG_BLK_DEV_LOOP_MIN_COUNT loop block devices if the max_loop
commandline parameter is not specified, and allowing max_loop to
be respected for all values, including 0.
This allows environments that can create all of their required loop
block devices on demand to not have to unnecessarily preallocate loop
block devices.
Fixes: 7328508274 ("remove artificial software max_loop limit")
Cc: stable@vger.kernel.org
Cc: Ken Chen <kenchen@google.com>
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Link: https://lore.kernel.org/r/20221208212902.765781-1-isaacmanjarres@google.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c490a0b5a4 upstream.
The userspace can configure a loop using an ioctl call, wherein
a configuration of type loop_config is passed (see lo_ioctl()'s
case on line 1550 of drivers/block/loop.c). This proceeds to call
loop_configure() which in turn calls loop_set_status_from_info()
(see line 1050 of loop.c), passing &config->info which is of type
loop_info64*. This function then sets the appropriate values, like
the offset.
loop_device has lo_offset of type loff_t (see line 52 of loop.c),
which is typdef-chained to long long, whereas loop_info64 has
lo_offset of type __u64 (see line 56 of include/uapi/linux/loop.h).
The function directly copies offset from info to the device as
follows (See line 980 of loop.c):
lo->lo_offset = info->lo_offset;
This results in an overflow, which triggers a warning in iomap_iter()
due to a call to iomap_iter_done() which has:
WARN_ON_ONCE(iter->iomap.offset > iter->pos);
Thus, check for negative value during loop_set_status_from_info().
Bug report: https://syzkaller.appspot.com/bug?id=c620fe14aac810396d3c3edc9ad73848bf69a29e
Reported-and-tested-by: syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Siddh Raman Pant <code@siddh.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220823160810.181275-1-code@siddh.me
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b27824d31f ]
sprintf does not know the PAGE_SIZE maximum of the temporary buffer
used for outputting sysfs content and it's possible to overrun the
PAGE_SIZE buffer length.
Use a generic sysfs_emit function that knows the size of the
temporary buffer and ensures that no overrun is done for offset
attribute in
loop_attr_[offset|sizelimit|autoclear|partscan|dio]_show() callbacks.
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20220215213310.7264-2-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 06582bc86d ]
If backing file's filesystem has implemented ->fallocate(), we think the
loop device can support discard, then pass sb->s_blocksize as
discard_granularity. However, some underlying FS, such as overlayfs,
doesn't set sb->s_blocksize, and causes discard_granularity to be set as
zero, then the warning in __blkdev_issue_discard() is triggered.
Christoph suggested to pass kstatfs.f_bsize as discard granularity, and
this way is fine because kstatfs.f_bsize means 'Optimal transfer block
size', which still matches with definition of discard granularity.
So fix the issue by setting discard_granularity as kstatfs.f_bsize if it
is available, otherwise claims discard isn't supported.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Reported-by: Pei Zhang <pezhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220126035830.296465-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
syzbot is reporting circular locking problem at __loop_clr_fd() [1], for
commit a160c6159d ("block: add an optional probe callback to
major_names") is calling the module's probe function with major_names_lock
held.
Fortunately, since commit 990e78116d ("block: loop: fix deadlock
between open and remove") stopped holding loop_ctl_mutex in lo_open(),
current role of loop_ctl_mutex is to serialize access to loop_index_idr
and loop_add()/loop_remove(); in other words, management of id for IDR.
To avoid holding loop_ctl_mutex during whole add/remove operation, use
a bool flag to indicate whether the loop device is ready for use.
loop_unregister_transfer() which is called from cleanup_cryptoloop()
currently has possibility of use-after-free problem due to lack of
serialization between kfree() from loop_remove() from loop_control_remove()
and mutex_lock() from unregister_transfer_cb(). But since lo->lo_encryption
should be already NULL when this function is called due to module unload,
and commit 222013f9ac ("cryptoloop: add a deprecation warning")
indicates that we will remove this function shortly, this patch updates
this function to emit warning instead of checking lo->lo_encryption.
Holding loop_ctl_mutex in loop_exit() is pointless, for all users must
close /dev/loop-control and /dev/loop$num (in order to drop module's
refcount to 0) before loop_exit() starts, and nobody can open
/dev/loop-control or /dev/loop$num afterwards.
Link: https://syzkaller.appspot.com/bug?id=7bb10e8b62f83e4d445cdf4c13d69e407e629558 [1]
Reported-by: syzbot <syzbot+f61766d5763f9e7a118f@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/adb1e792-fc0e-ee81-7ea0-0906fc36419d@i-love.sakura.ne.jp
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We noticed that the user interface of Android devices becomes very slow
under memory pressure. This is because Android uses the zram driver on top
of the loop driver for swapping, because under memory pressure the swap
code alternates reads and writes quickly, because mq-deadline is the
default scheduler for loop devices and because mq-deadline delays writes by
five seconds for such a workload with default settings. Fix this by making
the kernel select I/O scheduler 'none' from inside add_disk() for loop
devices. This default can be overridden at any time from user space,
e.g. via a udev rule. This approach has an advantage compared to changing
the I/O scheduler from userspace from 'mq-deadline' into 'none', namely
that synchronize_rcu() does not get called.
This patch changes the default I/O scheduler for loop devices from
'mq-deadline' into 'none'.
Additionally, this patch reduces the Android boot time on my test setup
with 0.5 seconds compared to configuring the loop I/O scheduler from user
space.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Martijn Coenen <maco@android.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210805174200.3250718-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 6cc8e74308 ("loop: scale loop device by introducing per
device lock") re-opened a race window for NULL pointer dereference at
loop_validate_file() where commit 310ca162d7 ("block/loop: Use
global lock for ioctl() operation.") has closed.
Although we need to guarantee that other loop devices will not change
during traversal, we can't take remote "struct loop_device"->lo_mutex
inside loop_validate_file() in order to avoid AB-BA deadlock. Therefore,
introduce a global lock dedicated for loop_validate_file() which is
conditionally taken before local "struct loop_device"->lo_mutex is taken.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 6cc8e74308 ("loop: scale loop device by introducing per device lock")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block driver updates from Jens Axboe:
"Pretty calm round, mostly just NVMe and a bit of MD:
- NVMe updates (via Christoph)
- improve the APST configuration algorithm (Alexey Bogoslavsky)
- look for StorageD3Enable on companion ACPI device
(Mario Limonciello)
- allow selecting the network interface for TCP connections
(Martin Belanger)
- misc cleanups (Amit Engel, Chaitanya Kulkarni, Colin Ian King,
Christoph)
- move the ACPI StorageD3 code to drivers/acpi/ and add quirks
for certain AMD CPUs (Mario Limonciello)
- zoned device support for nvmet (Chaitanya Kulkarni)
- fix the rules for changing the serial number in nvmet
(Noam Gottlieb)
- various small fixes and cleanups (Dan Carpenter, JK Kim,
Chaitanya Kulkarni, Hannes Reinecke, Wesley Sheng, Geert
Uytterhoeven, Daniel Wagner)
- MD updates (Via Song)
- iostats rewrite (Guoqing Jiang)
- raid5 lock contention optimization (Gal Ofri)
- Fall through warning fix (Gustavo)
- Misc fixes (Gustavo, Jiapeng)"
* tag 'for-5.14/drivers-2021-06-29' of git://git.kernel.dk/linux-block: (78 commits)
nvmet: use NVMET_MAX_NAMESPACES to set nn value
loop: Fix missing discard support when using LOOP_CONFIGURE
nvme.h: add missing nvme_lba_range_type endianness annotations
nvme: remove zeroout memset call for struct
nvme-pci: remove zeroout memset call for struct
nvmet: remove zeroout memset call for struct
nvmet: add ZBD over ZNS backend support
nvmet: add Command Set Identifier support
nvmet: add nvmet_req_bio put helper for backends
nvmet: add req cns error complete helper
block: export blk_next_bio()
nvmet: remove local variable
nvmet: use nvme status value directly
nvmet: use u32 type for the local variable nsid
nvmet: use u32 for nvmet_subsys max_nsid
nvmet: use req->cmd directly in file-ns fast path
nvmet: use req->cmd directly in bdev-ns fast path
nvmet: make ver stable once connection established
nvmet: allow mn change if subsys not discovered
nvmet: make sn stable once connection was established
...
Patch series "Charge loop device i/o to issuing cgroup", v14.
The loop device runs all i/o to the backing file on a separate kworker
thread which results in all i/o being charged to the root cgroup. This
allows a loop device to be used to trivially bypass resource limits and
other policy. This patch series fixes this gap in accounting.
A simple script to demonstrate this behavior on cgroupv2 machine:
'''
#!/bin/bash
set -e
CGROUP=/sys/fs/cgroup/test.slice
LOOP_DEV=/dev/loop0
if [[ ! -d $CGROUP ]]
then
sudo mkdir $CGROUP
fi
grep oom_kill $CGROUP/memory.events
# Set a memory limit, write more than that limit to tmpfs -> OOM kill
sudo unshare -m bash -c "
echo \$\$ > $CGROUP/cgroup.procs;
echo 0 > $CGROUP/memory.swap.max;
echo 64M > $CGROUP/memory.max;
mount -t tmpfs -o size=512m tmpfs /tmp;
dd if=/dev/zero of=/tmp/file bs=1M count=256" || true
grep oom_kill $CGROUP/memory.events
# Set a memory limit, write more than that limit through loopback
# device -> no OOM kill
sudo unshare -m bash -c "
echo \$\$ > $CGROUP/cgroup.procs;
echo 0 > $CGROUP/memory.swap.max;
echo 64M > $CGROUP/memory.max;
mount -t tmpfs -o size=512m tmpfs /tmp;
truncate -s 512m /tmp/backing_file
losetup $LOOP_DEV /tmp/backing_file
dd if=/dev/zero of=$LOOP_DEV bs=1M count=256;
losetup -D $LOOP_DEV" || true
grep oom_kill $CGROUP/memory.events
'''
Naively charging cgroups could result in priority inversions through the
single kworker thread in the case where multiple cgroups are
reading/writing to the same loop device. This patch series does some
minor modification to the loop driver so that each cgroup can make forward
progress independently to avoid this inversion.
With this patch series applied, the above script triggers OOM kills when
writing through the loop device as expected.
This patch (of 3):
Existing uses of loop device may have multiple cgroups reading/writing to
the same device. Simply charging resources for I/O to the backing file
could result in priority inversion where one cgroup gets synchronously
blocked, holding up all other I/O to the loop device.
In order to avoid this priority inversion, we use a single workqueue where
each work item is a "struct loop_worker" which contains a queue of struct
loop_cmds to issue. The loop device maintains a tree mapping blk css_id
-> loop_worker. This allows each cgroup to independently make forward
progress issuing I/O to the backing file.
There is also a single queue for I/O associated with the rootcg which can
be used in cases of extreme memory shortage where we cannot allocate a
loop_worker.
The locking for the tree and queues is fairly heavy handed - we acquire a
per-loop-device spinlock any time either is accessed. The existing
implementation serializes all I/O through a single thread anyways, so I
don't believe this is any worse.
[colin.king@canonical.com: fixes]
Link: https://lkml.kernel.org/r/20210610173944.1203706-1-schatzberg.dan@gmail.com
Link: https://lkml.kernel.org/r/20210610173944.1203706-2-schatzberg.dan@gmail.com
Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Without calling loop_config_discard() the discard flag and parameters
aren't set/updated for the loop device and worst-case they could
indicate discard support when it isn't the case (ex: if the
LOOP_SET_STATUS ioctl was used with a different file prior to
LOOP_CONFIGURE).
Cc: <stable@vger.kernel.org> # 5.8.x-
Fixes: 3448914e8c ("loop: Add LOOP_CONFIGURE ioctl")
Signed-off-by: Kristian Klausen <kristian@klausen.dk>
Link: https://lore.kernel.org/r/20210618115157.31452-1-kristian@klausen.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We must release the queue before freeing the tagset.
Fixes: 1c99502fae ("loop: use blk_mq_alloc_disk and blk_cleanup_disk")
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block fixes from Jens Axboe:
"A few fixes that should go into 5.13:
- Fix a regression deadlock introduced in this release between open
and remove of a bdev (Christoph)
- Fix an async_xor md regression in this release (Xiao)
- Fix bcache oversized read issue (Coly)"
* tag 'block-5.13-2021-06-12' of git://git.kernel.dk/linux-block:
block: loop: fix deadlock between open and remove
async_xor: check src_offs is not NULL before updating it
bcache: avoid oversized read request in cache missing code path
bcache: remove bcache device self-defined readahead
Commit c76f48eb5c ("block: take bd_mutex around delete_partitions in
del_gendisk") adds disk->part0->bd_mutex in del_gendisk(), this way
causes the following AB/BA deadlock between removing loop and opening
loop:
1) loop_control_ioctl(LOOP_CTL_REMOVE)
-> mutex_lock(&loop_ctl_mutex)
-> del_gendisk
-> mutex_lock(&disk->part0->bd_mutex)
2) blkdev_get_by_dev
-> mutex_lock(&disk->part0->bd_mutex)
-> lo_open
-> mutex_lock(&loop_ctl_mutex)
Add a new Lo_deleting state to remove the need for clearing
->private_data and thus holding loop_ctl_mutex in the ioctl
LOOP_CTL_REMOVE path.
Based on an analysis and earlier patch from
Ming Lei <ming.lei@redhat.com>.
Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: c76f48eb5c ("block: take bd_mutex around delete_partitions in del_gendisk")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210605140950.5800-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull more block updates from Jens Axboe:
"A few stragglers (and one due to me missing it originally), and fixes
for changes in this merge window mostly. In particular:
- blktrace cleanups (Chaitanya, Greg)
- Kill dead blk_pm_* functions (Bart)
- Fixes for the bio alloc changes (Christoph)
- Fix for the partition changes (Christoph, Ming)
- Fix for turning off iopoll with polled IO inflight (Jeffle)
- nbd disconnect fix (Josef)
- loop fsync error fix (Mauricio)
- kyber update depth fix (Yang)
- max_sectors alignment fix (Mikulas)
- Add bio_max_segs helper (Matthew)"
* tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-block: (21 commits)
block: Add bio_max_segs
blktrace: fix documentation for blk_fill_rw()
block: memory allocations in bounce_clone_bio must not fail
block: remove the gfp_mask argument to bounce_clone_bio
block: fix bounce_clone_bio for passthrough bios
block-crypto-fallback: use a bio_set for splitting bios
block: fix logging on capacity change
blk-settings: align max_sectors on "logical_block_size" boundary
block: reopen the device in blkdev_reread_part
block: don't skip empty device in in disk_uevent
blktrace: remove debugfs file dentries from struct blk_trace
nbd: handle device refs for DESTROY_ON_DISCONNECT properly
kyber: introduce kyber_depth_updated()
loop: fix I/O error on fsync() in detached loop devices
block: fix potential IO hang when turning off io_poll
block: get rid of the trace rq insert wrapper
blktrace: fix blk_rq_merge documentation
blktrace: fix blk_rq_issue documentation
blktrace: add blk_fill_rwbs documentation comment
block: remove superfluous param in blk_fill_rwbs()
...
Pull misc vfs updates from Al Viro:
"Assorted stuff pile - no common topic here"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
whack-a-mole: don't open-code iminor/imajor
9p: fix misuse of sscanf() in v9fs_stat2inode()
audit_alloc_mark(): don't open-code ERR_CAST()
fs/inode.c: make inode_init_always() initialize i_ino to 0
vfs: don't unnecessarily clone write access for writable fds
There's an I/O error on fsync() in a detached loop device
if it has been previously attached.
The issue is write cache is enabled in the attach path in
loop_configure() but it isn't disabled in the detach path;
thus it remains enabled in the block device regardless of
whether it is attached or not.
Now fsync() can get an I/O request that will just be failed
later in loop_queue_rq() as device's state is not 'Lo_bound'.
So, disable write cache in the detach path.
Do so based on the queue flag, not the loop device flag for
read-only (used to enable) as the queue flag can be changed
via sysfs even on read-only loop devices (e.g., losetup -r.)
Test-case:
# DEV=/dev/loop7
# IMG=/tmp/image
# truncate --size 1M $IMG
# losetup $DEV $IMG
# losetup -d $DEV
Before:
# strace -e fsync parted -s $DEV print 2>&1 | grep fsync
fsync(3) = -1 EIO (Input/output error)
Warning: Error fsyncing/closing /dev/loop7: Input/output error
[ 982.529929] blk_update_request: I/O error, dev loop7, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0
After:
# strace -e fsync parted -s $DEV print 2>&1 | grep fsync
fsync(3) = 0
Co-developed-by: Eric Desrochers <eric.desrochers@canonical.com>
Signed-off-by: Eric Desrochers <eric.desrochers@canonical.com>
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Tested-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently, loop device has only one global lock: loop_ctl_mutex.
This becomes hot in scenarios where many loop devices are used.
Scale it by introducing per-device lock: lo_mutex that protects
modifications of all fields in struct loop_device.
Keep loop_ctl_mutex to protect global data: loop_index_idr, loop_lookup,
loop_add.
The new lock ordering requirement is that loop_ctl_mutex must be taken
before lo_mutex.
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block driver updates from Jens Axboe:
"Nothing major in here:
- NVMe pull request from Christoph:
- nvmet passthrough improvements (Chaitanya Kulkarni)
- fcloop error injection support (James Smart)
- read-only support for zoned namespaces without Zone Append
(Javier González)
- improve some error message (Minwoo Im)
- reject I/O to offline fabrics namespaces (Victor Gladkov)
- PCI queue allocation cleanups (Niklas Schnelle)
- remove an unused allocation in nvmet (Amit Engel)
- a Kconfig spelling fix (Colin Ian King)
- nvme_req_qid simplication (Baolin Wang)
- MD pull request from Song:
- Fix race condition in md_ioctl() (Dae R. Jeong)
- Initialize read_slot properly for raid10 (Kevin Vigor)
- Code cleanup (Pankaj Gupta)
- md-cluster resync/reshape fix (Zhao Heming)
- Move null_blk into its own directory (Damien Le Moal)
- null_blk zone and discard improvements (Damien Le Moal)
- bcache race fix (Dongsheng Yang)
- Set of rnbd fixes/improvements (Gioh Kim, Guoqing Jiang, Jack Wang,
Lutz Pogrell, Md Haris Iqbal)
- lightnvm NULL pointer deref fix (tangzhenhao)
- sr in_interrupt() removal (Sebastian Andrzej Siewior)
- FC endpoint security support for s390/dasd (Jan Höppner, Sebastian
Ott, Vineeth Vijayan). From the s390 arch guys, arch bits included
as it made it easier for them to funnel the feature through the
block driver tree.
- Follow up fixes (Colin Ian King)"
* tag 'for-5.11/drivers-2020-12-14' of git://git.kernel.dk/linux-block: (64 commits)
block: drop dead assignments in loop_init()
sr: Remove in_interrupt() usage in sr_init_command().
sr: Switch the sector size back to 2048 if sr_read_sector() changed it.
cdrom: Reset sector_size back it is not 2048.
drivers/lightnvm: fix a null-ptr-deref bug in pblk-core.c
null_blk: Move driver into its own directory
null_blk: Allow controlling max_hw_sectors limit
null_blk: discard zones on reset
null_blk: cleanup discard handling
null_blk: Improve implicit zone close
null_blk: improve zone locking
block: Align max_hw_sectors to logical blocksize
null_blk: Fail zone append to conventional zones
null_blk: Fix zone size initialization
bcache: fix race between setting bdev state to none and new write request direct to backing
block/rnbd: fix a null pointer dereference on dev->blk_symlink_name
block/rnbd-clt: Dynamically alloc buffer for pathname & blk_symlink_name
block/rnbd: call kobject_put in the failure path
Documentation/ABI/rnbd-srv: add document for force_close
block/rnbd-srv: close a mapped device from server side.
...
Commit 8410d38c25 ("loop: use __register_blkdev to allocate devices on
demand") simplified loop_init(); so computing the range of the block region
is not required anymore and can be dropped.
Drop dead assignments in loop_init().
As compilers will detect these unneeded assignments and optimize this,
the resulting object code is identical before and after this change.
No functional change. No change in object code.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that the hd_struct always has a block device attached to it, there is
no need for having two size field that just get out of sync.
Additionally the field in hd_struct did not use proper serialization,
possibly allowing for torn writes. By only using the block_device field
this problem also gets fixed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: Chao Yu <yuchao0@huawei.com> [f2fs]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stop passing the whole device as a separate argument given that it
can be trivially deducted and cleanup the !holder debug check.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that each hd_struct has a reference to the corresponding
block_device, there is no need for the bd_contains pointer. Add
a bdev_whole() helper to look up the whole device block_device
struture instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch the block device lookup interfaces to directly work with a dev_t
so that struct block_device references are only acquired by the
blkdev_get variants (and the blk-cgroup special case). This means that
we now don't need an extra reference in the inode and can generally
simplify handling of struct block_device to keep the lookups contained
in the core block layer code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Coly Li <colyli@suse.de> [bcache]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
set_blocksize is used by file systems to use their preferred buffer cache
block size. Block drivers should not set it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
