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ANDROID: block: Do not set the I/O priority for zoned writes

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The I/O priority set by the ionice command or by the blk-ioprio cgroup
policy may cause the mq-deadline I/O scheduler to submit zoned writes in
the wrong order and hence to trigger unaligned write errors. Fix this by
not applying these I/O priority policies on sequential zoned writes.

Bug: 269471019
Bug: 415836627
Change-Id: I88ae04b697239f1aa27404cbf35c5a96d3a73a1f
Signed-off-by: Bart Van Assche <bvanassche@google.com>
This commit is contained in:
Bart Van Assche
2025-04-08 14:22:52 -07:00
parent 30ce6652ee
commit d6f0f66569
1 changed files with 33 additions and 0 deletions
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33
block/blk-core.c
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@@ -882,8 +882,41 @@ end_io:
}
EXPORT_SYMBOL(submit_bio_noacct);
#ifdef CONFIG_BLK_DEV_ZONED
/**
* blk_bio_is_seq_zoned_write() - Check if @bio requires write serialization.
* @bio: Bio to examine.
*
* Note: REQ_OP_ZONE_APPEND bios do not require serialization.
* Note: this function treats conventional zones on a zoned block device as
* sequential zones. This is fine since zoned UFS devices have no conventional
* zones.
*/
static bool blk_bio_is_seq_zoned_write(struct bio *bio)
{
if (!bdev_is_zoned(bio->bi_bdev))
return false;
return bio_op(bio) == REQ_OP_WRITE ||
bio_op(bio) == REQ_OP_WRITE_ZEROES;
}
#else
static bool blk_bio_is_seq_zoned_write(struct bio *bio)
{
return false;
}
#endif
static void bio_set_ioprio(struct bio *bio)
{
/*
* Do not set the I/O priority of sequential zoned write bios because
* this could lead to reordering by the mq-deadline I/O scheduler and
* hence to unaligned write errors.
*/
if (blk_bio_is_seq_zoned_write(bio))
return;
/* Nobody set ioprio so far? Initialize it based on task's nice value */
if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) == IOPRIO_CLASS_NONE)
bio->bi_ioprio = get_current_ioprio();