fix: low probability IO hang problem#123
Merged
eryugey merged 1 commit intocloud-hypervisor:masterfrom May 8, 2023
Merged
Conversation
aftersnow
requested review from
bergwolf,
eryugey,
imeoer,
jiangliu and
liubogithub
as code owners
aftersnow
force-pushed
the
fix-io-hang-issue
branch
2 times, most recently
from
721692b to
a19613a
Compare
eryugey
reviewed
Apr 25, 2023
we found some applications may encounter the io hang: Call Trace: [<ffffffff8173ca3b>] ? __schedule+0x23b/0x780 [<ffffffff8173cfb6>] schedule+0x36/0x80 [<ffffffffa0377840>] request_wait_answer+0xc0/0x1f0 [fuse] [<ffffffff810d5350>] ? prepare_to_wait_event+0x100/0x100 [<ffffffffa03779f4>] __fuse_request_send+0x84/0x90 [fuse] [<ffffffffa0377a27>] fuse_request_send+0x27/0x30 [fuse] [<ffffffffa037adaf>] fuse_simple_request+0xcf/0x1a0 [fuse] [<ffffffffa037c80b>] fuse_dentry_revalidate+0x18b/0x300 [fuse] [<ffffffff8125b79b>] lookup_fast+0x2eb/0x310 [<ffffffff8125c527>] walk_component+0x47/0x310 [<ffffffff8125d7c7>] path_lookupat+0x67/0x120 [<ffffffff811b6e99>] ? generic_file_read_iter+0x699/0x960 [<ffffffff81260421>] filename_lookup+0xb1/0x180 [<ffffffff812235c6>] ? kmem_cache_alloc+0x146/0x1a0 [<ffffffff8126001f>] ? getname_flags+0x4f/0x1f0 [<ffffffff8126003f>] ? getname_flags+0x6f/0x1f0 [<ffffffff81254896>] vfs_fstatat+0x66/0xc0 [<ffffffff81254e51>] SYSC_newlstat+0x31/0x60 The root cause MAYBE that fuse daemon encounters errors (bytes_to_cstr() error) when processing requests, but does not reply to kernel. This patch fixes the issue by adding a reply. Because the exception does not produce any logs, we cannot be 100% sure that it is the cause. However, after applying this patch in our production environment, the issue no longer occurs. Signed-off-by: winters.zc <winters.zc@antfin.com>
aftersnow
force-pushed
the
fix-io-hang-issue
branch
from
a19613a to
743c570
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
we found some applications may encounter the io hang:
Call Trace:
[] ? __schedule+0x23b/0x780
[] schedule+0x36/0x80
[] request_wait_answer+0xc0/0x1f0 [fuse]
[] ? prepare_to_wait_event+0x100/0x100
[] __fuse_request_send+0x84/0x90 [fuse]
[] fuse_request_send+0x27/0x30 [fuse]
[] fuse_simple_request+0xcf/0x1a0 [fuse]
[]fuse_dentry_revalidate+0x18b/0x300 [fuse]
[] lookup_fast+0x2eb/0x310
[] walk_component+0x47/0x310
[] path_lookupat+0x67/0x120
[] ? generic_file_read_iter+0x699/0x960
[] filename_lookup+0xb1/0x180
[] ? kmem_cache_alloc+0x146/0x1a0
[] ? getname_flags+0x4f/0x1f0
[] ? getname_flags+0x6f/0x1f0
[] user_path_at_empty+0x36/0x40
[] vfs_fstatat+0x66/0xc0
...
The root cause MAYBE that fuse daemon encounters errors (bytes_to_cstr() error) when processing requests, but does not reply to kernel.
This patch fixes the issue by adding a reply. Because the exception does not produce any logs, we cannot be 100% sure that it is the cause. However, after applying this patch in our production environment, the issue no longer occurs.