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>
The pointer node is being initialized with a value that is never
read, it is being re-assigned the same value a little futher on.
Remove the redundant initialization. Cleans up clang scan warning:
drivers/block/loop.c:823:19: warning: Value stored to 'node' during
its initialization is never read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220113001432.1331871-1-colin.i.king@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block driver updates from Jens Axboe:
- mtip32xx pci cleanups (Bjorn)
- mtip32xx conversion to generic power management (Vaibhav)
- rsxx pci powermanagement cleanups (Bjorn)
- Remove the rsxx driver. This hardware never saw much adoption, and
it's been end of lifed for a while. (Christoph)
- MD pull request from Song:
- REQ_NOWAIT support (Vishal Verma)
- raid6 benchmark optimization (Dirk Müller)
- Fix for acct bioset (Xiao Ni)
- Clean up max_queued_requests (Mariusz Tkaczyk)
- PREEMPT_RT optimization (Davidlohr Bueso)
- Use default_groups in kobj_type (Greg Kroah-Hartman)
- Use attribute groups in pktcdvd and rnbd (Greg)
- NVMe pull request from Christoph:
- increment request genctr on completion (Keith Busch, Geliang
Tang)
- add a 'iopolicy' module parameter (Hannes Reinecke)
- print out valid arguments when reading from /dev/nvme-fabrics
(Hannes Reinecke)
- Use struct_group() in drbd (Kees)
- null_blk fixes (Ming)
- Get rid of congestion logic in pktcdvd (Neil)
- Floppy ejection hang fix (Tasos)
- Floppy max user request size fix (Xiongwei)
- Loop locking fix (Tetsuo)
* tag 'for-5.17/drivers-2022-01-11' of git://git.kernel.dk/linux-block: (32 commits)
md: use default_groups in kobj_type
md: Move alloc/free acct bioset in to personality
lib/raid6: Use strict priority ranking for pq gen() benchmarking
lib/raid6: skip benchmark of non-chosen xor_syndrome functions
md: fix spelling of "its"
md: raid456 add nowait support
md: raid10 add nowait support
md: raid1 add nowait support
md: add support for REQ_NOWAIT
md: drop queue limitation for RAID1 and RAID10
md/raid5: play nice with PREEMPT_RT
block/rnbd-clt-sysfs: use default_groups in kobj_type
pktcdvd: convert to use attribute groups
block: null_blk: only set set->nr_maps as 3 if active poll_queues is > 0
nvme: add 'iopolicy' module parameter
nvme: drop unused variable ctrl in nvme_setup_cmd
nvme: increment request genctr on completion
nvme-fabrics: print out valid arguments when reading from /dev/nvme-fabrics
block: remove the rsxx driver
rsxx: Drop PCI legacy power management
...
Pull block updates from Jens Axboe:
- Unify where the struct request handling code is located in the blk-mq
code (Christoph)
- Header cleanups (Christoph)
- Clean up the io_context handling code (Christoph, me)
- Get rid of ->rq_disk in struct request (Christoph)
- Error handling fix for add_disk() (Christoph)
- request allocation cleanusp (Christoph)
- Documentation updates (Eric, Matthew)
- Remove trivial crypto unregister helper (Eric)
- Reduce shared tag overhead (John)
- Reduce poll_stats memory overhead (me)
- Known indirect function call for dio (me)
- Use atomic references for struct request (me)
- Support request list issue for block and NVMe (me)
- Improve queue dispatch pinning (Ming)
- Improve the direct list issue code (Keith)
- BFQ improvements (Jan)
- Direct completion helper and use it in mmc block (Sebastian)
- Use raw spinlock for the blktrace code (Wander)
- fsync error handling fix (Ye)
- Various fixes and cleanups (Lukas, Randy, Yang, Tetsuo, Ming, me)
* tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-block: (132 commits)
MAINTAINERS: add entries for block layer documentation
docs: block: remove queue-sysfs.rst
docs: sysfs-block: document virt_boundary_mask
docs: sysfs-block: document stable_writes
docs: sysfs-block: fill in missing documentation from queue-sysfs.rst
docs: sysfs-block: add contact for nomerges
docs: sysfs-block: sort alphabetically
docs: sysfs-block: move to stable directory
block: don't protect submit_bio_checks by q_usage_counter
block: fix old-style declaration
nvme-pci: fix queue_rqs list splitting
block: introduce rq_list_move
block: introduce rq_list_for_each_safe macro
block: move rq_list macros to blk-mq.h
block: drop needless assignment in set_task_ioprio()
block: remove unnecessary trailing '\'
bio.h: fix kernel-doc warnings
block: check minor range in device_add_disk()
block: use "unsigned long" for blk_validate_block_size().
block: fix error unwinding in device_add_disk
...
syzbot is reporting circular locking problem at __loop_clr_fd() [1], for
commit 87579e9b7d ("loop: use worker per cgroup instead of kworker")
is calling destroy_workqueue() with lo->lo_mutex held.
Since all functions where lo->lo_state matters are already checking
lo->lo_state with lo->lo_mutex held (in order to avoid racing with e.g.
ioctl(LOOP_CTL_REMOVE)), and __loop_clr_fd() can be called from either
ioctl(LOOP_CLR_FD) xor close(), lo->lo_state == Lo_rundown is considered
as an exclusive lock for __loop_clr_fd(). Therefore, hold lo->lo_mutex
inside __loop_clr_fd() only when asserting/updating lo->lo_state.
Since ioctl(LOOP_CLR_FD) depends on lo->lo_state == Lo_bound, a valid
lo->lo_backing_file must have been assigned by ioctl(LOOP_SET_FD) or
ioctl(LOOP_CONFIGURE). Thus, we can remove lo->lo_backing_file test,
and convert __loop_clr_fd() into a void function.
Link: https://syzkaller.appspot.com/bug?extid=63614029dfb79abd4383 [1]
Reported-by: syzbot <syzbot+63614029dfb79abd4383@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/8ebe3b2e-8975-7f26-0620-7144a3b8b8cd@i-love.sakura.ne.jp
Signed-off-by: Jens Axboe <axboe@kernel.dk>
All modern drivers can support extra partitions using the extended
dev_t. In fact except for the ioctl method drivers never even see
partitions in normal operation.
So remove the GENHD_FL_EXT_DEVT and allow extra partitions for all
block devices that do support partitions, and require those that
do not support partitions to explicit disallow them using
GENHD_FL_NO_PART.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211122130625.1136848-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull more block driver updates from Jens Axboe:
- Last series adding error handling support for add_disk() in drivers.
After this one, and once the SCSI side has been merged, we can
finally annotate add_disk() as must_check. (Luis)
- bcache fixes (Coly)
- zram fixes (Ming)
- ataflop locking fix (Tetsuo)
- nbd fixes (Ye, Yu)
- MD merge via Song
- Cleanup (Yang)
- sysfs fix (Guoqing)
- Misc fixes (Geert, Wu, luo)
* tag 'for-5.16/drivers-2021-11-09' of git://git.kernel.dk/linux-block: (34 commits)
bcache: Revert "bcache: use bvec_virt"
ataflop: Add missing semicolon to return statement
floppy: address add_disk() error handling on probe
ataflop: address add_disk() error handling on probe
block: update __register_blkdev() probe documentation
ataflop: remove ataflop_probe_lock mutex
mtd/ubi/block: add error handling support for add_disk()
block/sunvdc: add error handling support for add_disk()
z2ram: add error handling support for add_disk()
nvdimm/pmem: use add_disk() error handling
nvdimm/pmem: cleanup the disk if pmem_release_disk() is yet assigned
nvdimm/blk: add error handling support for add_disk()
nvdimm/blk: avoid calling del_gendisk() on early failures
nvdimm/btt: add error handling support for add_disk()
nvdimm/btt: use goto error labels on btt_blk_init()
loop: Remove duplicate assignments
drbd: Fix double free problem in drbd_create_device
nvdimm/btt: do not call del_gendisk() if not needed
bcache: fix use-after-free problem in bcache_device_free()
zram: replace fsync_bdev with sync_blockdev
...
Pull kiocb->ki_complete() cleanup from Jens Axboe:
"This removes the res2 argument from kiocb->ki_complete().
Only the USB gadget code used it, everybody else passes 0. The USB
guys checked the user gadget code they could find, and everybody just
uses res as expected for the async interface"
* tag 'for-5.16/ki_complete-2021-10-29' of git://git.kernel.dk/linux-block:
fs: get rid of the res2 iocb->ki_complete argument
usb: remove res2 argument from gadget code completions
Pull block driver updates from Jens Axboe:
- paride driver cleanups (Christoph)
- Remove cryptoloop support (Christoph)
- null_blk poll support (me)
- Now that add_disk() supports proper error handling, add it to various
drivers (Luis)
- Make ataflop actually work again (Michael)
- s390 dasd fixes (Stefan, Heiko)
- nbd fixes (Yu, Ye)
- Remove redundant wq flush in mtip32xx (Christophe)
- NVMe updates
- fix a multipath partition scanning deadlock (Hannes Reinecke)
- generate uevent once a multipath namespace is operational again
(Hannes Reinecke)
- support unique discovery controller NQNs (Hannes Reinecke)
- fix use-after-free when a port is removed (Israel Rukshin)
- clear shadow doorbell memory on resets (Keith Busch)
- use struct_size (Len Baker)
- add error handling support for add_disk (Luis Chamberlain)
- limit the maximal queue size for RDMA controllers (Max Gurtovoy)
- use a few more symbolic names (Max Gurtovoy)
- fix error code in nvme_rdma_setup_ctrl (Max Gurtovoy)
- add support for ->map_queues on FC (Saurav Kashyap)
- support the current discovery subsystem entry (Hannes Reinecke)
- use flex_array_size and struct_size (Len Baker)
- bcache fixes (Christoph, Coly, Chao, Lin, Qing)
- MD updates (Christoph, Guoqing, Xiao)
- Misc fixes (Dan, Ding, Jiapeng, Shin'ichiro, Ye)
* tag 'for-5.16/drivers-2021-10-29' of git://git.kernel.dk/linux-block: (117 commits)
null_blk: Fix handling of submit_queues and poll_queues attributes
block: ataflop: Fix warning comparing pointer to 0
bcache: replace snprintf in show functions with sysfs_emit
bcache: move uapi header bcache.h to bcache code directory
nvmet: use flex_array_size and struct_size
nvmet: register discovery subsystem as 'current'
nvmet: switch check for subsystem type
nvme: add new discovery log page entry definitions
block: ataflop: more blk-mq refactoring fixes
block: remove support for cryptoloop and the xor transfer
mtd: add add_disk() error handling
rnbd: add error handling support for add_disk()
um/drivers/ubd_kern: add error handling support for add_disk()
m68k/emu/nfblock: add error handling support for add_disk()
xen-blkfront: add error handling support for add_disk()
bcache: add error handling support for add_disk()
dm: add add_disk() error handling
block: aoe: fixup coccinelle warnings
nvmet: use struct_size over open coded arithmetic
nvme: drop scan_lock and always kick requeue list when removing namespaces
...
The second argument was only used by the USB gadget code, yet everyone
pays the overhead of passing a zero to be passed into aio, where it
ends up being part of the aio res2 value.
Now that everybody is passing in zero, kill off the extra argument.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Support for cyrptoloop has been officially marked broken and deprecated
in favor of dm-crypt (which supports the same broken algorithms if
needed) in Linux 2.6.4 (released in March 2004), and support for it has
been entirely removed from losetup in util-linux 2.23 (released in April
2013). The XOR transfer has never been more than a toy to demonstrate
the transfer in the bad old times of crypto export restrictions.
Remove them as they have some nasty interactions with loop device life
times due to the iteration over all loop devices in
loop_unregister_transfer.
Suggested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211019075639.2333969-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Ming Lei
Tetsuo Handa
Colin Ian King
Linus Torvalds
Christoph Hellwig
luo penghao
Xie Yongji
Jens Axboe
Luis Chamberlain
Bart Van Assche
Matteo Croce