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| author | Mike Snitzer <snitzer@redhat.com> | 2022-02-17 23:40:02 -0500 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2022-02-21 15:19:08 -0500 |
| commit | 9f6dc633761006f974701d4c88da71ab68670749 (patch) | |
| tree | fcabdaea0e9f0c3306be15f39ee4dd9f71978c73 /drivers/md/dm-stats.h | |
| parent | bcd2be763252f3a4d5fc4d6008d4d96c601ee74b (diff) | |
| download | lwn-9f6dc633761006f974701d4c88da71ab68670749.tar.gz lwn-9f6dc633761006f974701d4c88da71ab68670749.zip | |
dm: interlock pending dm_io and dm_wait_for_bios_completion
Commit d208b89401e0 ("dm: fix mempool NULL pointer race when
completing IO") didn't go far enough.
When bio_end_io_acct ends the count of in-flight I/Os may reach zero
and the DM device may be suspended. There is a possibility that the
suspend races with dm_stats_account_io.
Fix this by adding percpu "pending_io" counters to track outstanding
dm_io. Move kicking of suspend queue to dm_io_dec_pending(). Also,
rename md_in_flight_bios() to dm_in_flight_bios() and update it to
iterate all pending_io counters.
Fixes: d208b89401e0 ("dm: fix mempool NULL pointer race when completing IO")
Cc: stable@vger.kernel.org
Co-developed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-stats.h')
0 files changed, 0 insertions, 0 deletions