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[ Upstream commit cf7b39a0cbf6bf57aa07a008d46cf695add05b4c ]
We get a bug:
BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x11c/0x404
lib/iov_iter.c:1139
Read of size 8 at addr ffff0000d3fb11f8 by task
CPU: 0 PID: 12582 Comm: syz-executor.2 Not tainted
5.10.0-00843-g352c8610ccd2 #2
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x2d0 arch/arm64/kernel/stacktrace.c:132
show_stack+0x28/0x34 arch/arm64/kernel/stacktrace.c:196
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x110/0x164 lib/dump_stack.c:118
print_address_description+0x78/0x5c8 mm/kasan/report.c:385
__kasan_report mm/kasan/report.c:545 [inline]
kasan_report+0x148/0x1e4 mm/kasan/report.c:562
check_memory_region_inline mm/kasan/generic.c:183 [inline]
__asan_load8+0xb4/0xbc mm/kasan/generic.c:252
iov_iter_revert+0x11c/0x404 lib/iov_iter.c:1139
io_read fs/io_uring.c:3421 [inline]
io_issue_sqe+0x2344/0x2d64 fs/io_uring.c:5943
__io_queue_sqe+0x19c/0x520 fs/io_uring.c:6260
io_queue_sqe+0x2a4/0x590 fs/io_uring.c:6326
io_submit_sqe fs/io_uring.c:6395 [inline]
io_submit_sqes+0x4c0/0xa04 fs/io_uring.c:6624
__do_sys_io_uring_enter fs/io_uring.c:9013 [inline]
__se_sys_io_uring_enter fs/io_uring.c:8960 [inline]
__arm64_sys_io_uring_enter+0x190/0x708 fs/io_uring.c:8960
__invoke_syscall arch/arm64/kernel/syscall.c:36 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:48 [inline]
el0_svc_common arch/arm64/kernel/syscall.c:158 [inline]
do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:227
el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367
el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383
el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670
Allocated by task 12570:
stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121
kasan_save_stack mm/kasan/common.c:48 [inline]
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc+0xdc/0x120 mm/kasan/common.c:461
kasan_kmalloc+0xc/0x14 mm/kasan/common.c:475
__kmalloc+0x23c/0x334 mm/slub.c:3970
kmalloc include/linux/slab.h:557 [inline]
__io_alloc_async_data+0x68/0x9c fs/io_uring.c:3210
io_setup_async_rw fs/io_uring.c:3229 [inline]
io_read fs/io_uring.c:3436 [inline]
io_issue_sqe+0x2954/0x2d64 fs/io_uring.c:5943
__io_queue_sqe+0x19c/0x520 fs/io_uring.c:6260
io_queue_sqe+0x2a4/0x590 fs/io_uring.c:6326
io_submit_sqe fs/io_uring.c:6395 [inline]
io_submit_sqes+0x4c0/0xa04 fs/io_uring.c:6624
__do_sys_io_uring_enter fs/io_uring.c:9013 [inline]
__se_sys_io_uring_enter fs/io_uring.c:8960 [inline]
__arm64_sys_io_uring_enter+0x190/0x708 fs/io_uring.c:8960
__invoke_syscall arch/arm64/kernel/syscall.c:36 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:48 [inline]
el0_svc_common arch/arm64/kernel/syscall.c:158 [inline]
do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:227
el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367
el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383
el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670
Freed by task 12570:
stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121
kasan_save_stack mm/kasan/common.c:48 [inline]
kasan_set_track+0x38/0x6c mm/kasan/common.c:56
kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:355
__kasan_slab_free+0x124/0x150 mm/kasan/common.c:422
kasan_slab_free+0x10/0x1c mm/kasan/common.c:431
slab_free_hook mm/slub.c:1544 [inline]
slab_free_freelist_hook mm/slub.c:1577 [inline]
slab_free mm/slub.c:3142 [inline]
kfree+0x104/0x38c mm/slub.c:4124
io_dismantle_req fs/io_uring.c:1855 [inline]
__io_free_req+0x70/0x254 fs/io_uring.c:1867
io_put_req_find_next fs/io_uring.c:2173 [inline]
__io_queue_sqe+0x1fc/0x520 fs/io_uring.c:6279
__io_req_task_submit+0x154/0x21c fs/io_uring.c:2051
io_req_task_submit+0x2c/0x44 fs/io_uring.c:2063
task_work_run+0xdc/0x128 kernel/task_work.c:151
get_signal+0x6f8/0x980 kernel/signal.c:2562
do_signal+0x108/0x3a4 arch/arm64/kernel/signal.c:658
do_notify_resume+0xbc/0x25c arch/arm64/kernel/signal.c:722
work_pending+0xc/0x180
blkdev_read_iter can truncate iov_iter's count since the count + pos may
exceed the size of the blkdev. This will confuse io_read that we have
consume the iovec. And once we do the iov_iter_revert in io_read, we
will trigger the slab-out-of-bounds. Fix it by reexpand the count with
size has been truncated.
blkdev_write_iter can trigger the problem too.
Signed-off-by: yangerkun <yangerkun@huawei.com>
Acked-by: Pavel Begunkov <asml.silencec@gmail.com>
Link: https://lore.kernel.org/r/20210401071807.3328235-1-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit f8b78caf21d5bc3fcfc40c18898f9d52ed1451a5 ]
If IOCB_NOWAIT is set on submission, then that needs to get propagated to
REQ_NOWAIT on the block side. Otherwise we completely lose this
information, and any issuer of IOCB_NOWAIT IO will potentially end up
blocking on eg request allocation on the storage side.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b849dd84b6ccfe32622988b79b7b073861fcf9f7 ]
While trying to "dd" to the block device for a USB stick, I
encountered a hung task warning (blocked for > 120 seconds). I
managed to come up with an easy way to reproduce this on my system
(where /dev/sdb is the block device for my USB stick) with:
while true; do dd if=/dev/zero of=/dev/sdb bs=4M; done
With my reproduction here are the relevant bits from the hung task
detector:
INFO: task udevd:294 blocked for more than 122 seconds.
...
udevd D 0 294 1 0x00400008
Call trace:
...
mutex_lock_nested+0x40/0x50
__blkdev_get+0x7c/0x3d4
blkdev_get+0x118/0x138
blkdev_open+0x94/0xa8
do_dentry_open+0x268/0x3a0
vfs_open+0x34/0x40
path_openat+0x39c/0xdf4
do_filp_open+0x90/0x10c
do_sys_open+0x150/0x3c8
...
...
Showing all locks held in the system:
...
1 lock held by dd/2798:
#0: ffffff814ac1a3b8 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0x50/0x204
...
dd D 0 2798 2764 0x00400208
Call trace:
...
schedule+0x8c/0xbc
io_schedule+0x1c/0x40
wait_on_page_bit_common+0x238/0x338
__lock_page+0x5c/0x68
write_cache_pages+0x194/0x500
generic_writepages+0x64/0xa4
blkdev_writepages+0x24/0x30
do_writepages+0x48/0xa8
__filemap_fdatawrite_range+0xac/0xd8
filemap_write_and_wait+0x30/0x84
__blkdev_put+0x88/0x204
blkdev_put+0xc4/0xe4
blkdev_close+0x28/0x38
__fput+0xe0/0x238
____fput+0x1c/0x28
task_work_run+0xb0/0xe4
do_notify_resume+0xfc0/0x14bc
work_pending+0x8/0x14
The problem appears related to the fact that my USB disk is terribly
slow and that I have a lot of RAM in my system to cache things.
Specifically my writes seem to be happening at ~15 MB/s and I've got
~4 GB of RAM in my system that can be used for buffering. To write 4
GB of buffer to disk thus takes ~4000 MB / ~15 MB/s = ~267 seconds.
The 267 second number is a problem because in __blkdev_put() we call
sync_blockdev() while holding the bd_mutex. Any other callers who
want the bd_mutex will be blocked for the whole time.
The problem is made worse because I believe blkdev_put() specifically
tells other tasks (namely udev) to go try to access the device at right
around the same time we're going to hold the mutex for a long time.
Putting some traces around this (after disabling the hung task detector),
I could confirm:
dd: 437.608600: __blkdev_put() right before sync_blockdev() for sdb
udevd: 437.623901: blkdev_open() right before blkdev_get() for sdb
dd: 661.468451: __blkdev_put() right after sync_blockdev() for sdb
udevd: 663.820426: blkdev_open() right after blkdev_get() for sdb
A simple fix for this is to realize that sync_blockdev() works fine if
you're not holding the mutex. Also, it's not the end of the world if
you sync a little early (though it can have performance impacts).
Thus we can make a guess that we're going to need to do the sync and
then do it without holding the mutex. We still do one last sync with
the mutex but it should be much, much faster.
With this, my hung task warnings for my test case are gone.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 2d3a8e2deddea6c89961c422ec0c5b851e648c14 ]
In blkdev_get() we call __blkdev_get() to do some internal jobs and if
there is some errors in __blkdev_get(), the bdput() is called which
means we have released the refcount of the bdev (actually the refcount of
the bdev inode). This means we cannot access bdev after that point. But
acctually bdev is still accessed in blkdev_get() after calling
__blkdev_get(). This results in use-after-free if the refcount is the
last one we released in __blkdev_get(). Let's take a look at the
following scenerio:
CPU0 CPU1 CPU2
blkdev_open blkdev_open Remove disk
bd_acquire
blkdev_get
__blkdev_get del_gendisk
bdev_unhash_inode
bd_acquire bdev_get_gendisk
bd_forget failed because of unhashed
bdput
bdput (the last one)
bdev_evict_inode
access bdev => use after free
[ 459.350216] BUG: KASAN: use-after-free in __lock_acquire+0x24c1/0x31b0
[ 459.351190] Read of size 8 at addr ffff88806c815a80 by task syz-executor.0/20132
[ 459.352347]
[ 459.352594] CPU: 0 PID: 20132 Comm: syz-executor.0 Not tainted 4.19.90 #2
[ 459.353628] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 459.354947] Call Trace:
[ 459.355337] dump_stack+0x111/0x19e
[ 459.355879] ? __lock_acquire+0x24c1/0x31b0
[ 459.356523] print_address_description+0x60/0x223
[ 459.357248] ? __lock_acquire+0x24c1/0x31b0
[ 459.357887] kasan_report.cold+0xae/0x2d8
[ 459.358503] __lock_acquire+0x24c1/0x31b0
[ 459.359120] ? _raw_spin_unlock_irq+0x24/0x40
[ 459.359784] ? lockdep_hardirqs_on+0x37b/0x580
[ 459.360465] ? _raw_spin_unlock_irq+0x24/0x40
[ 459.361123] ? finish_task_switch+0x125/0x600
[ 459.361812] ? finish_task_switch+0xee/0x600
[ 459.362471] ? mark_held_locks+0xf0/0xf0
[ 459.363108] ? __schedule+0x96f/0x21d0
[ 459.363716] lock_acquire+0x111/0x320
[ 459.364285] ? blkdev_get+0xce/0xbe0
[ 459.364846] ? blkdev_get+0xce/0xbe0
[ 459.365390] __mutex_lock+0xf9/0x12a0
[ 459.365948] ? blkdev_get+0xce/0xbe0
[ 459.366493] ? bdev_evict_inode+0x1f0/0x1f0
[ 459.367130] ? blkdev_get+0xce/0xbe0
[ 459.367678] ? destroy_inode+0xbc/0x110
[ 459.368261] ? mutex_trylock+0x1a0/0x1a0
[ 459.368867] ? __blkdev_get+0x3e6/0x1280
[ 459.369463] ? bdev_disk_changed+0x1d0/0x1d0
[ 459.370114] ? blkdev_get+0xce/0xbe0
[ 459.370656] blkdev_get+0xce/0xbe0
[ 459.371178] ? find_held_lock+0x2c/0x110
[ 459.371774] ? __blkdev_get+0x1280/0x1280
[ 459.372383] ? lock_downgrade+0x680/0x680
[ 459.373002] ? lock_acquire+0x111/0x320
[ 459.373587] ? bd_acquire+0x21/0x2c0
[ 459.374134] ? do_raw_spin_unlock+0x4f/0x250
[ 459.374780] blkdev_open+0x202/0x290
[ 459.375325] do_dentry_open+0x49e/0x1050
[ 459.375924] ? blkdev_get_by_dev+0x70/0x70
[ 459.376543] ? __x64_sys_fchdir+0x1f0/0x1f0
[ 459.377192] ? inode_permission+0xbe/0x3a0
[ 459.377818] path_openat+0x148c/0x3f50
[ 459.378392] ? kmem_cache_alloc+0xd5/0x280
[ 459.379016] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 459.379802] ? path_lookupat.isra.0+0x900/0x900
[ 459.380489] ? __lock_is_held+0xad/0x140
[ 459.381093] do_filp_open+0x1a1/0x280
[ 459.381654] ? may_open_dev+0xf0/0xf0
[ 459.382214] ? find_held_lock+0x2c/0x110
[ 459.382816] ? lock_downgrade+0x680/0x680
[ 459.383425] ? __lock_is_held+0xad/0x140
[ 459.384024] ? do_raw_spin_unlock+0x4f/0x250
[ 459.384668] ? _raw_spin_unlock+0x1f/0x30
[ 459.385280] ? __alloc_fd+0x448/0x560
[ 459.385841] do_sys_open+0x3c3/0x500
[ 459.386386] ? filp_open+0x70/0x70
[ 459.386911] ? trace_hardirqs_on_thunk+0x1a/0x1c
[ 459.387610] ? trace_hardirqs_off_caller+0x55/0x1c0
[ 459.388342] ? do_syscall_64+0x1a/0x520
[ 459.388930] do_syscall_64+0xc3/0x520
[ 459.389490] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 459.390248] RIP: 0033:0x416211
[ 459.390720] Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83
04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f
05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d
01
[ 459.393483] RSP: 002b:00007fe45dfe9a60 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
[ 459.394610] RAX: ffffffffffffffda RBX: 00007fe45dfea6d4 RCX: 0000000000416211
[ 459.395678] RDX: 00007fe45dfe9b0a RSI: 0000000000000002 RDI: 00007fe45dfe9b00
[ 459.396758] RBP: 000000000076bf20 R08: 0000000000000000 R09: 000000000000000a
[ 459.397930] R10: 0000000000000075 R11: 0000000000000293 R12: 00000000ffffffff
[ 459.399022] R13: 0000000000000bd9 R14: 00000000004cdb80 R15: 000000000076bf2c
[ 459.400168]
[ 459.400430] Allocated by task 20132:
[ 459.401038] kasan_kmalloc+0xbf/0xe0
[ 459.401652] kmem_cache_alloc+0xd5/0x280
[ 459.402330] bdev_alloc_inode+0x18/0x40
[ 459.402970] alloc_inode+0x5f/0x180
[ 459.403510] iget5_locked+0x57/0xd0
[ 459.404095] bdget+0x94/0x4e0
[ 459.404607] bd_acquire+0xfa/0x2c0
[ 459.405113] blkdev_open+0x110/0x290
[ 459.405702] do_dentry_open+0x49e/0x1050
[ 459.406340] path_openat+0x148c/0x3f50
[ 459.406926] do_filp_open+0x1a1/0x280
[ 459.407471] do_sys_open+0x3c3/0x500
[ 459.408010] do_syscall_64+0xc3/0x520
[ 459.408572] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 459.409415]
[ 459.409679] Freed by task 1262:
[ 459.410212] __kasan_slab_free+0x129/0x170
[ 459.410919] kmem_cache_free+0xb2/0x2a0
[ 459.411564] rcu_process_callbacks+0xbb2/0x2320
[ 459.412318] __do_softirq+0x225/0x8ac
Fix this by delaying bdput() to the end of blkdev_get() which means we
have finished accessing bdev.
Fixes: 77ea887e433a ("implement in-kernel gendisk events handling")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 56939e014a6c212b317414faa307029e2e80c3b9 ]
It turns out that there is one use case for programs being able to
write to swap devices, and that is the userspace hibernation code.
Quick fix: disable the S_SWAPFILE check if hibernation is configured.
Fixes: dc617f29dbe5 ("vfs: don't allow writes to swap files")
Reported-by: Domenico Andreoli <domenico.andreoli@linux.com>
Reported-by: Marian Klein <mkleinsoft@gmail.com>
Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit cba22d86e0a10b7070d2e6a7379dbea51aa0883c upstream.
Currently, block device size in not updated on second and further open
for block devices where partition scan is disabled. This is particularly
annoying for example for DVD drives as that means block device size does
not get updated once the media is inserted into a drive if the device is
already open when inserting the media. This is actually always the case
for example when pktcdvd is in use.
Fix the problem by revalidating block device size on every open even for
devices with partition scan disabled.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Laura Abbott <labbott@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 731dc4868311ee097757b8746eaa1b4f8b2b4f1c upstream.
Factor out code handling revalidation of bdev on disk change into a
common helper.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Laura Abbott <labbott@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Pull swap access updates from Darrick Wong:
"Prohibit writing to active swap files and swap partitions.
There's no non-malicious use case for allowing userspace to scribble
on storage that the kernel thinks it owns"
* tag 'vfs-5.4-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
vfs: don't allow writes to swap files
mm: set S_SWAPFILE on blockdev swap devices
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Don't let userspace write to an active swap file because the kernel
effectively has a long term lease on the storage and things could get
seriously corrupted if we let this happen.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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We had a few issues with this code, and there's still a problem around
how we deal with error handling for chained/split bios. For now, just
revert the code and we'll try again with a thoroug solution. This
reverts commits:
e15c2ffa1091 ("block: fix O_DIRECT error handling for bio fragments")
0eb6ddfb865c ("block: Fix __blkdev_direct_IO() for bio fragments")
6a43074e2f46 ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
893a1c97205a ("blk-mq: allow REQ_NOWAIT to return an error inline")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Commit 89e524c04fa9 ("loop: Fix mount(2) failure due to race with
LOOP_SET_FD") converted blkdev_get() to use the new helpers for
finishing claiming of a block device. However the conversion botched the
error handling in blkdev_get() and thus the bdev has been marked as held
even in case __blkdev_get() returned error. This led to occasional
warnings with block/001 test from blktests like:
kernel: WARNING: CPU: 5 PID: 907 at fs/block_dev.c:1899 __blkdev_put+0x396/0x3a0
Correct the error handling.
CC: stable@vger.kernel.org
Fixes: 89e524c04fa9 ("loop: Fix mount(2) failure due to race with LOOP_SET_FD")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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0eb6ddfb865c tried to fix this up, but introduced a use-after-free
of dio. Additionally, we still had an issue with error handling,
as reported by Darrick:
"I noticed a regression in xfs/747 (an unreleased xfstest for the
xfs_scrub media scanning feature) on 5.3-rc3. I'll condense that down
to a simpler reproducer:
error-test: 0 209 linear 8:48 0
error-test: 209 1 error
error-test: 210 6446894 linear 8:48 210
Basically we have a ~3G /dev/sdd and we set up device mapper to fail IO
for sector 209 and to pass the io to the scsi device everywhere else.
On 5.3-rc3, performing a directio pread of this range with a < 1M buffer
(in other words, a request for fewer than MAX_BIO_PAGES bytes) yields
EIO like you'd expect:
pread64(3, 0x7f880e1c7000, 1048576, 0) = -1 EIO (Input/output error)
pread: Input/output error
+++ exited with 0 +++
But doing it with a larger buffer succeeds(!):
pread64(3, "XFSB\0\0\20\0\0\0\0\0\0\fL\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 1146880, 0) = 1146880
read 1146880/1146880 bytes at offset 0
1 MiB, 1 ops; 0.0009 sec (1.124 GiB/sec and 1052.6316 ops/sec)
+++ exited with 0 +++
(Note that the part of the buffer corresponding to the dm-error area is
uninitialized)
On 5.3-rc2, both commands would fail with EIO like you'd expect. The
only change between rc2 and rc3 is commit 0eb6ddfb865c ("block: Fix
__blkdev_direct_IO() for bio fragments").
AFAICT we end up in __blkdev_direct_IO with a 1120K buffer, which gets
split into two bios: one for the first BIO_MAX_PAGES worth of data (1MB)
and a second one for the 96k after that."
Fix this by noting that it's always safe to dereference dio if we get
BLK_QC_T_EAGAIN returned, as end_io hasn't been run for that case. So
we can safely increment the dio size before calling submit_bio(), and
then decrement it on failure (not that it really matters, as the bio
and dio are going away).
For error handling, return to the original method of just using 'ret'
for tracking the error, and the size tracking in dio->size.
Fixes: 0eb6ddfb865c ("block: Fix __blkdev_direct_IO() for bio fragments")
Fixes: 6a43074e2f46 ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
The recent fix to properly handle IOCB_NOWAIT for async O_DIRECT IO
(patch 6a43074e2f46) introduced two problems with BIO fragment handling
for direct IOs:
1) The dio size processed is calculated by incrementing the ret variable
by the size of the bio fragment issued for the dio. However, this size
is obtained directly from bio->bi_iter.bi_size AFTER the bio submission
which may result in referencing the bi_size value after the bio
completed, resulting in an incorrect value use.
2) The ret variable is not incremented by the size of the last bio
fragment issued for the bio, leading to an invalid IO size being
returned to the user.
Fix both problem by using dio->size (which is incremented before the bio
submission) to update the value of ret after bio submissions, including
for the last bio fragment issued.
Fixes: 6a43074e2f46 ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
Reported-by: Masato Suzuki <masato.suzuki@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Commit 33ec3e53e7b1 ("loop: Don't change loop device under exclusive
opener") made LOOP_SET_FD ioctl acquire exclusive block device reference
while it updates loop device binding. However this can make perfectly
valid mount(2) fail with EBUSY due to racing LOOP_SET_FD holding
temporarily the exclusive bdev reference in cases like this:
for i in {a..z}{a..z}; do
dd if=/dev/zero of=$i.image bs=1k count=0 seek=1024
mkfs.ext2 $i.image
mkdir mnt$i
done
echo "Run"
for i in {a..z}{a..z}; do
mount -o loop -t ext2 $i.image mnt$i &
done
Fix the problem by not getting full exclusive bdev reference in
LOOP_SET_FD but instead just mark the bdev as being claimed while we
update the binding information. This just blocks new exclusive openers
instead of failing them with EBUSY thus fixing the problem.
Fixes: 33ec3e53e7b1 ("loop: Don't change loop device under exclusive opener")
Cc: stable@vger.kernel.org
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Pull block fixes from Jens Axboe:
- Several io_uring fixes/improvements:
- Blocking fix for O_DIRECT (me)
- Latter page slowness for registered buffers (me)
- Fix poll hang under certain conditions (me)
- Defer sequence check fix for wrapped rings (Zhengyuan)
- Mismatch in async inc/dec accounting (Zhengyuan)
- Memory ordering issue that could cause stall (Zhengyuan)
- Track sequential defer in bytes, not pages (Zhengyuan)
- NVMe pull request from Christoph
- Set of hang fixes for wbt (Josef)
- Redundant error message kill for libahci (Ding)
- Remove unused blk_mq_sched_started_request() and related ops (Marcos)
- drbd dynamic alloc shash descriptor to reduce stack use (Arnd)
- blkcg ->pd_stat() non-debug print (Tejun)
- bcache memory leak fix (Wei)
- Comment fix (Akinobu)
- BFQ perf regression fix (Paolo)
* tag 'for-linus-20190726' of git://git.kernel.dk/linux-block: (24 commits)
io_uring: ensure ->list is initialized for poll commands
Revert "nvme-pci: don't create a read hctx mapping without read queues"
nvme: fix multipath crash when ANA is deactivated
nvme: fix memory leak caused by incorrect subsystem free
nvme: ignore subnqn for ADATA SX6000LNP
drbd: dynamically allocate shash descriptor
block: blk-mq: Remove blk_mq_sched_started_request and started_request
bcache: fix possible memory leak in bch_cached_dev_run()
io_uring: track io length in async_list based on bytes
io_uring: don't use iov_iter_advance() for fixed buffers
block: properly handle IOCB_NOWAIT for async O_DIRECT IO
blk-mq: allow REQ_NOWAIT to return an error inline
io_uring: add a memory barrier before atomic_read
rq-qos: use a mb for got_token
rq-qos: set ourself TASK_UNINTERRUPTIBLE after we schedule
rq-qos: don't reset has_sleepers on spurious wakeups
rq-qos: fix missed wake-ups in rq_qos_throttle
wait: add wq_has_single_sleeper helper
block, bfq: check also in-flight I/O in dispatch plugging
block: fix sysfs module parameters directory path in comment
...
|
|
A caller is supposed to pass in REQ_NOWAIT if we can't block for any
given operation, but O_DIRECT for block devices just ignore this. Hence
we'll block for various resource shortages on the block layer side,
like having to wait for requests.
Use the new REQ_NOWAIT_INLINE to ask for this error to be returned
inline, so we can handle it appropriately and return -EAGAIN to the
caller.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount updates from Al Viro:
"The first part of mount updates.
Convert filesystems to use the new mount API"
* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
mnt_init(): call shmem_init() unconditionally
constify ksys_mount() string arguments
don't bother with registering rootfs
init_rootfs(): don't bother with init_ramfs_fs()
vfs: Convert smackfs to use the new mount API
vfs: Convert selinuxfs to use the new mount API
vfs: Convert securityfs to use the new mount API
vfs: Convert apparmorfs to use the new mount API
vfs: Convert openpromfs to use the new mount API
vfs: Convert xenfs to use the new mount API
vfs: Convert gadgetfs to use the new mount API
vfs: Convert oprofilefs to use the new mount API
vfs: Convert ibmasmfs to use the new mount API
vfs: Convert qib_fs/ipathfs to use the new mount API
vfs: Convert efivarfs to use the new mount API
vfs: Convert configfs to use the new mount API
vfs: Convert binfmt_misc to use the new mount API
convenience helper: get_tree_single()
convenience helper get_tree_nodev()
vfs: Kill sget_userns()
...
|
|
Use bio_release_pages instead of duplicating it.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Use bio_release_pages instead of duplicating it.
Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
When hidden gendisk is revalidated, there's no point in revalidating
associated block device as there's none. We would thus just create new
bdev inode, report "detected capacity change from 0 to XXX" message and
evict the bdev inode again. Avoid this pointless dance and confusing
message in the kernel log.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Convert the bdev filesystem to the new internal mount API as the old
one will be obsoleted and removed. This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.
See Documentation/filesystems/mount_api.txt for more information.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Once upon a time we used to set ->d_name of e.g. pipefs root
so that d_path() on pipes would work. These days it's
completely pointless - dentries of pipes are not even connected
to pipefs root. However, mount_pseudo() had set the root
dentry name (passed as the second argument) and callers
kept inventing names to pass to it. Including those that
didn't *have* any non-root dentries to start with...
All of that had been pointless for about 8 years now; it's
time to get rid of that cargo-culting...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
linux/dax.h is included more than once.
Link: http://lkml.kernel.org/r/5c867e95.1c69fb81.4f15a.e5e4@mx.google.com
Signed-off-by: Sabyasachi Gupta <sabyasachi.linux@gmail.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
"Assorted stuff, with no common topic whatsoever..."
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
libfs: document simple_get_link()
Documentation/filesystems/Locking: fix ->get_link() prototype
Documentation/filesystems/vfs.txt: document how ->i_link works
Documentation/filesystems/vfs.txt: remove bogus "Last updated" date
fs: use timespec64 in relatime_need_update
fs/block_dev.c: remove unused include
|
|
Pull block updates from Jens Axboe:
"Nothing major in this series, just fixes and improvements all over the
map. This contains:
- Series of fixes for sed-opal (David, Jonas)
- Fixes and performance tweaks for BFQ (via Paolo)
- Set of fixes for bcache (via Coly)
- Set of fixes for md (via Song)
- Enabling multi-page for passthrough requests (Ming)
- Queue release fix series (Ming)
- Device notification improvements (Martin)
- Propagate underlying device rotational status in loop (Holger)
- Removal of mtip32xx trim support, which has been disabled for years
(Christoph)
- Improvement and cleanup of nvme command handling (Christoph)
- Add block SPDX tags (Christoph)
- Cleanup/hardening of bio/bvec iteration (Christoph)
- A few NVMe pull requests (Christoph)
- Removal of CONFIG_LBDAF (Christoph)
- Various little fixes here and there"
* tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block: (164 commits)
block: fix mismerge in bvec_advance
block: don't drain in-progress dispatch in blk_cleanup_queue()
blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release
blk-mq: always free hctx after request queue is freed
blk-mq: split blk_mq_alloc_and_init_hctx into two parts
blk-mq: free hw queue's resource in hctx's release handler
blk-mq: move cancel of requeue_work into blk_mq_release
blk-mq: grab .q_usage_counter when queuing request from plug code path
block: fix function name in comment
nvmet: protect discovery change log event list iteration
nvme: mark nvme_core_init and nvme_core_exit static
nvme: move command size checks to the core
nvme-fabrics: check more command sizes
nvme-pci: check more command sizes
nvme-pci: remove an unneeded variable initialization
nvme-pci: unquiesce admin queue on shutdown
nvme-pci: shutdown on timeout during deletion
nvme-pci: fix psdt field for single segment sgls
nvme-multipath: don't print ANA group state by default
nvme-multipath: split bios with the ns_head bio_set before submitting
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs inode freeing updates from Al Viro:
"Introduction of separate method for RCU-delayed part of
->destroy_inode() (if any).
Pretty much as posted, except that destroy_inode() stashes
->free_inode into the victim (anon-unioned with ->i_fops) before
scheduling i_callback() and the last two patches (sockfs conversion
and folding struct socket_wq into struct socket) are excluded - that
pair should go through netdev once davem reopens his tree"
* 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (58 commits)
orangefs: make use of ->free_inode()
shmem: make use of ->free_inode()
hugetlb: make use of ->free_inode()
overlayfs: make use of ->free_inode()
jfs: switch to ->free_inode()
fuse: switch to ->free_inode()
ext4: make use of ->free_inode()
ecryptfs: make use of ->free_inode()
ceph: use ->free_inode()
btrfs: use ->free_inode()
afs: switch to use of ->free_inode()
dax: make use of ->free_inode()
ntfs: switch to ->free_inode()
securityfs: switch to ->free_inode()
apparmor: switch to ->free_inode()
rpcpipe: switch to ->free_inode()
bpf: switch to ->free_inode()
mqueue: switch to ->free_inode()
ufs: switch to ->free_inode()
coda: switch to ->free_inode()
...
|
|
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Commit 399254aaf489211 ("block: add BIO_NO_PAGE_REF flag") introduces
BIO_NO_PAGE_REF, and once this flag is set for one bio, all pages
in the bio won't be get/put during IO.
However, if one bio is submitted via __blkdev_direct_IO_simple(),
even though BIO_NO_PAGE_REF is set, pages still may be put.
Fixes this issue by avoiding to put pages if BIO_NO_PAGE_REF is
set.
Fixes: 399254aaf489211 ("block: add BIO_NO_PAGE_REF flag")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
We only have two callers that need the integer loop iterator, and they
can easily maintain it themselves.
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Coly Li <colyli@suse.de>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
If the last bio returned is not dio->bio, the status of the bio will
not assigned to dio->bio if it is error. This will cause the whole IO
status wrong.
ksoftirqd/21-117 [021] ..s. 4017.966090: 8,0 C N 4883648 [0]
<idle>-0 [018] ..s. 4017.970888: 8,0 C WS 4924800 + 1024 [0]
<idle>-0 [018] ..s. 4017.970909: 8,0 D WS 4935424 + 1024 [<idle>]
<idle>-0 [018] ..s. 4017.970924: 8,0 D WS 4936448 + 321 [<idle>]
ksoftirqd/21-117 [021] ..s. 4017.995033: 8,0 C R 4883648 + 336 [65475]
ksoftirqd/21-117 [021] d.s. 4018.001988: myprobe1: (blkdev_bio_end_io+0x0/0x168) bi_status=7
ksoftirqd/21-117 [021] d.s. 4018.001992: myprobe: (aio_complete_rw+0x0/0x148) x0=0xffff802f2595ad80 res=0x12a000 res2=0x0
We always have to assign bio->bi_status to dio->bio.bi_status because we
will only check dio->bio.bi_status when we return the whole IO to
the upper layer.
Fixes: 542ff7bf18c6 ("block: new direct I/O implementation")
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Just remove unused include <linux/badblocks.h> from
fs/block_dev.c.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
If bio_iov_iter_get_pages() is called on an iov_iter that is flagged
with NO_REF, then we don't need to add a page reference for the pages
that we add.
Add BIO_NO_PAGE_REF to track this in the bio, so IO completion knows
not to drop a reference to these pages.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
For the upcoming async polled IO, we can't sleep allocating requests.
If we do, then we introduce a deadlock where the submitter already
has async polled IO in-flight, but can't wait for them to complete
since polled requests must be active found and reaped.
Utilize the helper in the blockdev DIRECT_IO code.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Just call blk_poll on the iocb cookie, we can derive the block device
from the inode trivially.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.
Given it is just one mechannical & simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
bd_set_size() updates also block device's block size. This is somewhat
unexpected from its name and at this point, only blkdev_open() uses this
functionality. Furthermore, this can result in changing block size under
a filesystem mounted on a loop device which leads to livelocks inside
__getblk_gfp() like:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 10863 Comm: syz-executor0 Not tainted 4.18.0-rc5+ #151
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x3f/0x50 kernel/kcov.c:106
...
Call Trace:
init_page_buffers+0x3e2/0x530 fs/buffer.c:904
grow_dev_page fs/buffer.c:947 [inline]
grow_buffers fs/buffer.c:1009 [inline]
__getblk_slow fs/buffer.c:1036 [inline]
__getblk_gfp+0x906/0xb10 fs/buffer.c:1313
__bread_gfp+0x2d/0x310 fs/buffer.c:1347
sb_bread include/linux/buffer_head.h:307 [inline]
fat12_ent_bread+0x14e/0x3d0 fs/fat/fatent.c:75
fat_ent_read_block fs/fat/fatent.c:441 [inline]
fat_alloc_clusters+0x8ce/0x16e0 fs/fat/fatent.c:489
fat_add_cluster+0x7a/0x150 fs/fat/inode.c:101
__fat_get_block fs/fat/inode.c:148 [inline]
...
Trivial reproducer for the problem looks like:
truncate -s 1G /tmp/image
losetup /dev/loop0 /tmp/image
mkfs.ext4 -b 1024 /dev/loop0
mount -t ext4 /dev/loop0 /mnt
losetup -c /dev/loop0
l /mnt
Fix the problem by moving initialization of a block device block size
into a separate function and call it when needed.
Thanks to Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> for help with
debugging the problem.
Reported-by: syzbot+9933e4476f365f5d5a1b@syzkaller.appspotmail.com
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
This mostly reverts commit 849a370016a5 ("block: avoid ordered task
state change for polled IO"). It was wrongly claiming that the ordering
wasn't necessary. The memory barrier _is_ necessary.
If something is truly polling and not going to sleep, it's the whole
state setting that is unnecessary, not the memory barrier. Whenever you
set your state to a sleeping state, you absolutely need the memory
barrier.
Note that sometimes the memory barrier can be elsewhere. For example,
the ordering might be provided by an external lock, or by setting the
process state to sleeping before adding yourself to the wait queue list
that is used for waking up (where the wait queue lock itself will
guarantee that any wakeup will correctly see the sleeping state).
But none of those cases were true here.
NOTE! Some of the polling paths may indeed be able to drop the state
setting entirely, at which point the memory barrier also goes away.
(Also note that this doesn't revert the TASK_RUNNING cases: there is no
race between a wakeup and setting the process state to TASK_RUNNING,
since the end result doesn't depend on ordering).
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Merge misc updates from Andrew Morton:
- large KASAN update to use arm's "software tag-based mode"
- a few misc things
- sh updates
- ocfs2 updates
- just about all of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (167 commits)
kernel/fork.c: mark 'stack_vm_area' with __maybe_unused
memcg, oom: notify on oom killer invocation from the charge path
mm, swap: fix swapoff with KSM pages
include/linux/gfp.h: fix typo
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race
hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization
memory_hotplug: add missing newlines to debugging output
mm: remove __hugepage_set_anon_rmap()
include/linux/vmstat.h: remove unused page state adjustment macro
mm/page_alloc.c: allow error injection
mm: migrate: drop unused argument of migrate_page_move_mapping()
blkdev: avoid migration stalls for blkdev pages
mm: migrate: provide buffer_migrate_page_norefs()
mm: migrate: move migrate_page_lock_buffers()
mm: migrate: lock buffers before migrate_page_move_mapping()
mm: migration: factor out code to compute expected number of page references
mm, page_alloc: enable pcpu_drain with zone capability
kmemleak: add config to select auto scan
mm/page_alloc.c: don't call kasan_free_pages() at deferred mem init
...
|
|
Currently, block device pages don't provide a ->migratepage callback and
thus fallback_migrate_page() is used for them. This handler cannot deal
with dirty pages in async mode and also with the case a buffer head is in
the LRU buffer head cache (as it has elevated b_count). Thus such page
can block memory offlining.
Fix the problem by using buffer_migrate_page_norefs() for migrating block
device pages. That function takes care of dropping bh LRU in case
migration would fail due to elevated buffer refcount to avoid stalls and
can also migrate dirty pages without writing them.
Link: http://lkml.kernel.org/r/20181211172143.7358-6-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The bio referencing has a trick that doesn't do any actual atomic
inc/dec on the reference count until we have to elevator to > 1. For the
async IO O_DIRECT case, we can't use the simple DIO variants, so we use
__blkdev_direct_IO(). It always grabs an extra reference to the bio
after allocation, which means we then enter the slower path of actually
having to do atomic_inc/dec on the count.
We don't need to do that for the async case, unless we end up going
multi-bio, in which case we're already doing huge amounts of IO. For the
smaller IO case (< BIO_MAX_PAGES), we can do without the extra ref.
Based on an earlier patch (and commit log) from Jens Axboe.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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blk_poll() has always kept spinning until it found an IO. This is
fine for SYNC polling, since we need to find one request we have
pending, but in preparation for ASYNC polling it can be beneficial
to just check if we have any entries available or not.
Existing callers are converted to pass in 'spin == true', to retain
the old behavior.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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For the core poll helper, the task state setting don't need to imply any
atomics, as it's the current task itself that is being modified and
we're not going to sleep.
For IRQ driven, the wakeup path have the necessary barriers to not need
us using the heavy handed version of the task state setting.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Those will go straight to issue inside blk-mq, so don't bother
setting up a block plug for them.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Inherit the iocb IOCB_HIPRI flag, and pass on REQ_HIPRI for
those kinds of requests.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If we're polling for IO on a device that doesn't use interrupts, then
IO completion loop (and wake of task) is done by submitting task itself.
If that is the case, then we don't need to enter the wake_up_process()
function, we can simply mark ourselves as TASK_RUNNING.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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We use IOCB_HIPRI to poll for IO in the caller instead of scheduling.
This information is not available for (or after) IO submission. The
driver may make different queue choices based on the type of IO, so
make the fact that we will poll for this IO known to the lower layers
as well.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Use accessor functions to access an iterator's type and direction. This
allows for the possibility of using some other method of determining the
type of iterator than if-chains with bitwise-AND conditions.
Signed-off-by: David Howells <dhowells@redhat.com>
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Pull block updates from Jens Axboe:
"First pull request for this merge window, there will also be a
followup request with some stragglers.
This pull request contains:
- Fix for a thundering heard issue in the wbt block code (Anchal
Agarwal)
- A few NVMe pull requests:
* Improved tracepoints (Keith)
* Larger inline data support for RDMA (Steve Wise)
* RDMA setup/teardown fixes (Sagi)
* Effects log suppor for NVMe target (Chaitanya Kulkarni)
* Buffered IO suppor for NVMe target (Chaitanya Kulkarni)
* TP4004 (ANA) support (Christoph)
* Various NVMe fixes
- Block io-latency controller support. Much needed support for
properly containing block devices. (Josef)
- Series improving how we handle sense information on the stack
(Kees)
- Lightnvm fixes and updates/improvements (Mathias/Javier et al)
- Zoned device support for null_blk (Matias)
- AIX partition fixes (Mauricio Faria de Oliveira)
- DIF checksum code made generic (Max Gurtovoy)
- Add support for discard in iostats (Michael Callahan / Tejun)
- Set of updates for BFQ (Paolo)
- Removal of async write support for bsg (Christoph)
- Bio page dirtying and clone fixups (Christoph)
- Set of bcache fix/changes (via Coly)
- Series improving blk-mq queue setup/teardown speed (Ming)
- Series improving merging performance on blk-mq (Ming)
- Lots of other fixes and cleanups from a slew of folks"
* tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block: (190 commits)
blkcg: Make blkg_root_lookup() work for queues in bypass mode
bcache: fix error setting writeback_rate through sysfs interface
null_blk: add lock drop/acquire annotation
Blk-throttle: reduce tail io latency when iops limit is enforced
block: paride: pd: mark expected switch fall-throughs
block: Ensure that a request queue is dissociated from the cgroup controller
block: Introduce blk_exit_queue()
blkcg: Introduce blkg_root_lookup()
block: Remove two superfluous #include directives
blk-mq: count the hctx as active before allocating tag
block: bvec_nr_vecs() returns value for wrong slab
bcache: trivial - remove tailing backslash in macro BTREE_FLAG
bcache: make the pr_err statement used for ENOENT only in sysfs_attatch section
bcache: set max writeback rate when I/O request is idle
bcache: add code comments for bset.c
bcache: fix mistaken comments in request.c
bcache: fix mistaken code comments in bcache.h
bcache: add a comment in super.c
bcache: avoid unncessary cache prefetch bch_btree_node_get()
bcache: display rate debug parameters to 0 when writeback is not running
...
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Pull block fixes from Jens Axboe:
"Bigger than usual at this time, mostly due to the O_DIRECT corruption
issue and the fact that I was on vacation last week. This contains:
- NVMe pull request with two fixes for the FC code, and two target
fixes (Christoph)
- a DIF bio reset iteration fix (Greg Edwards)
- two nbd reply and requeue fixes (Josef)
- SCSI timeout fixup (Keith)
- a small series that fixes an issue with bio_iov_iter_get_pages(),
which ended up causing corruption for larger sized O_DIRECT writes
that ended up racing with buffered writes (Martin Wilck)"
* tag 'for-linus-20180727' of git://git.kernel.dk/linux-block:
block: reset bi_iter.bi_done after splitting bio
block: bio_iov_iter_get_pages: pin more pages for multi-segment IOs
blkdev: __blkdev_direct_IO_simple: fix leak in error case
block: bio_iov_iter_get_pages: fix size of last iovec
nvmet: only check for filebacking on -ENOTBLK
nvmet: fixup crash on NULL device path
scsi: set timed out out mq requests to complete
blk-mq: export setting request completion state
nvme: if_ready checks to fail io to deleting controller
nvmet-fc: fix target sgl list on large transfers
nbd: handle unexpected replies better
nbd: don't requeue the same request twice.
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