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| author | Jan Kara <jack@suse.cz> | 2014-10-30 20:43:38 +0100 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2014-11-20 12:01:52 +0000 |
| commit | 0e4110b21c3989230c853e0c5c4158e7760eb565 (patch) | |
| tree | b23c89771af62c2f4343bb01b232ed8c588c8b0d /block | |
| parent | 0960c0d879677020ed1df86ce10fe7a92015b075 (diff) | |
| download | linux-stable-0e4110b21c3989230c853e0c5c4158e7760eb565.tar.gz linux-stable-0e4110b21c3989230c853e0c5c4158e7760eb565.tar.bz2 linux-stable-0e4110b21c3989230c853e0c5c4158e7760eb565.zip | |
block: Fix computation of merged request priority
commit ece9c72accdc45c3a9484dacb1125ce572647288 upstream.
Priority of a merged request is computed by ioprio_best(). If one of the
requests has undefined priority (IOPRIO_CLASS_NONE) and another request
has priority from IOPRIO_CLASS_BE, the function will return the
undefined priority which is wrong. Fix the function to properly return
priority of a request with the defined priority.
Fixes: d58cdfb89ce0c6bd5f81ae931a984ef298dbda20
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/ioprio.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/block/ioprio.c b/block/ioprio.c index e50170ca7c33..31666c92b46a 100644 --- a/block/ioprio.c +++ b/block/ioprio.c @@ -157,14 +157,16 @@ out: int ioprio_best(unsigned short aprio, unsigned short bprio) { - unsigned short aclass = IOPRIO_PRIO_CLASS(aprio); - unsigned short bclass = IOPRIO_PRIO_CLASS(bprio); + unsigned short aclass; + unsigned short bclass; - if (aclass == IOPRIO_CLASS_NONE) - aclass = IOPRIO_CLASS_BE; - if (bclass == IOPRIO_CLASS_NONE) - bclass = IOPRIO_CLASS_BE; + if (!ioprio_valid(aprio)) + aprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM); + if (!ioprio_valid(bprio)) + bprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM); + aclass = IOPRIO_PRIO_CLASS(aprio); + bclass = IOPRIO_PRIO_CLASS(bprio); if (aclass == bclass) return min(aprio, bprio); if (aclass > bclass) |