Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 14 11月, 2019 3 次提交
  3. 03 11月, 2019 2 次提交
  5. 20 8月, 2019 1 次提交
  7. 16 8月, 2019 1 次提交
    • J
      block: remove REQ_NOWAIT_INLINE · 7b6620d7
      由 Jens Axboe 提交于 
      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:

e15c2ffa ("block: fix O_DIRECT error handling for bio fragments")
0eb6ddfb ("block: Fix __blkdev_direct_IO() for bio fragments")
6a43074e ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
893a1c97 ("blk-mq: allow REQ_NOWAIT to return an error inline")
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      7b6620d7
  9. 08 8月, 2019 2 次提交
    • J
      bdev: Fixup error handling in blkdev_get() · e91455ba
      由 Jan Kara 提交于 
      Commit 89e524c0 ("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: 89e524c0 ("loop: Fix mount(2) failure due to race with LOOP_SET_FD")
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      e91455ba
    • J
      block: fix O_DIRECT error handling for bio fragments · e15c2ffa
      由 Jens Axboe 提交于 
      0eb6ddfb 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 0eb6ddfb ("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: 0eb6ddfb ("block: Fix __blkdev_direct_IO() for bio fragments")
Fixes: 6a43074e ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
Reported-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      e15c2ffa
  11. 02 8月, 2019 1 次提交
    • D
      block: Fix __blkdev_direct_IO() for bio fragments · 0eb6ddfb
      由 Damien Le Moal 提交于 
      The recent fix to properly handle IOCB_NOWAIT for async O_DIRECT IO
(patch 6a43074e) 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: 6a43074e ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
Reported-by: NMasato Suzuki <masato.suzuki@wdc.com>
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      0eb6ddfb
  13. 31 7月, 2019 1 次提交
    • J
      loop: Fix mount(2) failure due to race with LOOP_SET_FD · 89e524c0
      由 Jan Kara 提交于 
      Commit 33ec3e53 ("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: 33ec3e53 ("loop: Don't change loop device under exclusive opener")
Cc: stable@vger.kernel.org
Tested-by: NKai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      89e524c0
  15. 22 7月, 2019 1 次提交
    • J
      block: properly handle IOCB_NOWAIT for async O_DIRECT IO · 6a43074e
      由 Jens Axboe 提交于 
      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: NJens Axboe <axboe@kernel.dk>
      6a43074e
  17. 29 6月, 2019 2 次提交
  19. 27 5月, 2019 1 次提交
  21. 26 5月, 2019 2 次提交
    • D
      vfs: Convert bdev to use the new mount API · 9030d16e
      由 David Howells 提交于 
      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: NDavid Howells <dhowells@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      9030d16e
    • A
      mount_pseudo(): drop 'name' argument, switch to d_make_root() · 1f58bb18
      由 Al Viro 提交于 
      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: NAl Viro <viro@zeniv.linux.org.uk>
      1f58bb18
  23. 21 5月, 2019 1 次提交
  25. 15 5月, 2019 1 次提交
  27. 02 5月, 2019 1 次提交
  29. 01 5月, 2019 1 次提交
  31. 30 4月, 2019 1 次提交
  33. 12 4月, 2019 1 次提交
    • J
      block: fix the return errno for direct IO · a89afe58
      由 Jason Yan 提交于 
      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: 542ff7bf ("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: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      a89afe58
  35. 10 4月, 2019 1 次提交
  37. 19 3月, 2019 1 次提交
    • J
      block: add BIO_NO_PAGE_REF flag · 399254aa
      由 Jens Axboe 提交于 
      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: NJens Axboe <axboe@kernel.dk>
      399254aa
  39. 24 2月, 2019 2 次提交
  41. 15 2月, 2019 1 次提交
  43. 15 1月, 2019 1 次提交
    • J
      blockdev: Fix livelocks on loop device · 04906b2f
      由 Jan Kara 提交于 
      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: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      04906b2f
  45. 03 1月, 2019 1 次提交
    • L
      block: don't use un-ordered __set_current_state(TASK_UNINTERRUPTIBLE) · 1ac5cd49
      由 Linus Torvalds 提交于 
      This mostly reverts commit 849a3700 ("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: NLinus Torvalds <torvalds@linux-foundation.org>
      1ac5cd49
  47. 29 12月, 2018 1 次提交
  49. 30 11月, 2018 1 次提交
    • C
      block: avoid extra bio reference for async O_DIRECT · 531724ab
      由 Christoph Hellwig 提交于 
      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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      531724ab
  51. 26 11月, 2018 1 次提交
    • J
      block: make blk_poll() take a parameter on whether to spin or not · 0a1b8b87
      由 Jens Axboe 提交于 
      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: NJens Axboe <axboe@kernel.dk>
      0a1b8b87
  53. 19 11月, 2018 1 次提交
  55. 16 11月, 2018 3 次提交
  57. 08 11月, 2018 1 次提交
  59. 24 10月, 2018 1 次提交
  61. 27 7月, 2018 1 次提交