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author | Li Jinlin <lijinlin3@huawei.com> | 2022-07-25 06:20:50 +0300 |
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committer | Dan Williams <dan.j.williams@intel.com> | 2022-07-26 22:29:29 +0300 |
commit | 17d9c15c9b9e7fb285f7ac5367dfb5f00ff575e3 (patch) | |
tree | b633678586da7c39363e7ad463200b95da09f885 /tools/perf/pmu-events/arch/x86/cascadelakex/cache.json | |
parent | d34213ebfea31229411583716a9ebe3610bf2d29 (diff) | |
download | linux-17d9c15c9b9e7fb285f7ac5367dfb5f00ff575e3.tar.xz |
fsdax: Fix infinite loop in dax_iomap_rw()
I got an infinite loop and a WARNING report when executing a tail command
in virtiofs.
WARNING: CPU: 10 PID: 964 at fs/iomap/iter.c:34 iomap_iter+0x3a2/0x3d0
Modules linked in:
CPU: 10 PID: 964 Comm: tail Not tainted 5.19.0-rc7
Call Trace:
<TASK>
dax_iomap_rw+0xea/0x620
? __this_cpu_preempt_check+0x13/0x20
fuse_dax_read_iter+0x47/0x80
fuse_file_read_iter+0xae/0xd0
new_sync_read+0xfe/0x180
? 0xffffffff81000000
vfs_read+0x14d/0x1a0
ksys_read+0x6d/0xf0
__x64_sys_read+0x1a/0x20
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The tail command will call read() with a count of 0. In this case,
iomap_iter() will report this WARNING, and always return 1 which casuing
the infinite loop in dax_iomap_rw().
Fixing by checking count whether is 0 in dax_iomap_rw().
Fixes: ca289e0b95af ("fsdax: switch dax_iomap_rw to use iomap_iter")
Signed-off-by: Li Jinlin <lijinlin3@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220725032050.3873372-1-lijinlin3@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'tools/perf/pmu-events/arch/x86/cascadelakex/cache.json')
0 files changed, 0 insertions, 0 deletions