| Message ID | 20241217223809.683035-4-bvanassche@acm.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Three blk_mq_submit_bio() patches | expand |
On 2024/12/17 14:38, Bart Van Assche wrote: > The error handling code in blk_zone_plug_bio() and in the functions > called by blk_zone_plug_bio() cannot be understood without knowing > that these functions are only called by blk_mq_submit_bio(). Move > the error handling code in blk_mq_submit_bio() such that all error > handling code for blk_mq_submit_bio() occurs inside blk_mq_submit_bio() > itself. I am not a big fan of this. Furthermore, blk_zone_plug_bio() is also called from drivers/md/dm.c, which would need to have the same amount of additional code. Not nice. > > Cc: Damien Le Moal <dlemoal@kernel.org> > Cc: Christoph Hellwig <hch@lst.de> > Signed-off-by: Bart Van Assche <bvanassche@acm.org> > --- > block/blk-mq.c | 16 ++++++++-- > block/blk-zoned.c | 67 +++++++++++++++++++----------------------- > include/linux/blkdev.h | 13 ++++++-- > 3 files changed, 56 insertions(+), 40 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index f4300e608ed8..2449f412dd00 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -3095,8 +3095,20 @@ void blk_mq_submit_bio(struct bio *bio) > if (blk_mq_attempt_bio_merge(q, bio, nr_segs)) > goto queue_exit; > > - if (blk_queue_is_zoned(q) && blk_zone_plug_bio(bio, nr_segs)) > - goto queue_exit; > + if (blk_queue_is_zoned(q)) { > + switch (blk_zone_plug_bio(bio, nr_segs)) { > + case bzp_not_plugged: > + break; > + case bzp_plugged: > + goto queue_exit; > + case bzp_wouldblock: > + bio_wouldblock_error(bio); > + goto queue_exit; > + case bzp_failed: > + bio_io_error(bio); > + goto queue_exit; > + } > + } > > new_request: > if (rq) { > diff --git a/block/blk-zoned.c b/block/blk-zoned.c > index 4b0be40a8ea7..cb2c05d8b1eb 100644 > --- a/block/blk-zoned.c > +++ b/block/blk-zoned.c > @@ -675,8 +675,8 @@ static int disk_zone_sync_wp_offset(struct gendisk *disk, sector_t sector) > disk_report_zones_cb, &args); > } > > -static bool blk_zone_wplug_handle_reset_or_finish(struct bio *bio, > - unsigned int wp_offset) > +static enum blk_zone_plug_status > +blk_zone_wplug_handle_reset_or_finish(struct bio *bio, unsigned int wp_offset) > { > struct gendisk *disk = bio->bi_bdev->bd_disk; > sector_t sector = bio->bi_iter.bi_sector; > @@ -684,10 +684,8 @@ static bool blk_zone_wplug_handle_reset_or_finish(struct bio *bio, > unsigned long flags; > > /* Conventional zones cannot be reset nor finished. */ > - if (!bdev_zone_is_seq(bio->bi_bdev, sector)) { > - bio_io_error(bio); > - return true; > - } > + if (!bdev_zone_is_seq(bio->bi_bdev, sector)) > + return bzp_failed; > > /* > * No-wait reset or finish BIOs do not make much sense as the callers > @@ -713,10 +711,11 @@ static bool blk_zone_wplug_handle_reset_or_finish(struct bio *bio, > disk_put_zone_wplug(zwplug); > } > > - return false; > + return bzp_not_plugged; > } > > -static bool blk_zone_wplug_handle_reset_all(struct bio *bio) > +static enum blk_zone_plug_status > +blk_zone_wplug_handle_reset_all(struct bio *bio) > { > struct gendisk *disk = bio->bi_bdev->bd_disk; > struct blk_zone_wplug *zwplug; > @@ -739,7 +738,7 @@ static bool blk_zone_wplug_handle_reset_all(struct bio *bio) > } > } > > - return false; > + return bzp_not_plugged; > } > > static void disk_zone_wplug_schedule_bio_work(struct gendisk *disk, > @@ -964,7 +963,8 @@ static bool blk_zone_wplug_prepare_bio(struct blk_zone_wplug *zwplug, > return true; > } > > -static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) > +static enum blk_zone_plug_status > +blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) > { > struct gendisk *disk = bio->bi_bdev->bd_disk; > sector_t sector = bio->bi_iter.bi_sector; > @@ -980,19 +980,15 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) > * BIO-based devices, it is the responsibility of the driver to split > * the bio before submitting it. > */ > - if (WARN_ON_ONCE(bio_straddles_zones(bio))) { > - bio_io_error(bio); > - return true; > - } > + if (WARN_ON_ONCE(bio_straddles_zones(bio))) > + return bzp_failed; > > /* Conventional zones do not need write plugging. */ > if (!bdev_zone_is_seq(bio->bi_bdev, sector)) { > /* Zone append to conventional zones is not allowed. */ > - if (bio_op(bio) == REQ_OP_ZONE_APPEND) { > - bio_io_error(bio); > - return true; > - } > - return false; > + if (bio_op(bio) == REQ_OP_ZONE_APPEND) > + return bzp_failed; > + return bzp_not_plugged; > } > > if (bio->bi_opf & REQ_NOWAIT) > @@ -1001,10 +997,9 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) > zwplug = disk_get_and_lock_zone_wplug(disk, sector, gfp_mask, &flags); > if (!zwplug) { > if (bio->bi_opf & REQ_NOWAIT) > - bio_wouldblock_error(bio); > + return bzp_wouldblock; > else > - bio_io_error(bio); > - return true; > + return bzp_failed; > } > > /* Indicate that this BIO is being handled using zone write plugging. */ > @@ -1022,22 +1017,21 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) > > if (!blk_zone_wplug_prepare_bio(zwplug, bio)) { > spin_unlock_irqrestore(&zwplug->lock, flags); > - bio_io_error(bio); > - return true; > + return bzp_failed; > } > > zwplug->flags |= BLK_ZONE_WPLUG_PLUGGED; > > spin_unlock_irqrestore(&zwplug->lock, flags); > > - return false; > + return bzp_not_plugged; > > plug: > disk_zone_wplug_add_bio(disk, zwplug, bio, nr_segs); > > spin_unlock_irqrestore(&zwplug->lock, flags); > > - return true; > + return bzp_plugged; > } > > /** > @@ -1048,16 +1042,17 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) > * Handle write, write zeroes and zone append operations requiring emulation > * using zone write plugging. > * > - * Return true whenever @bio execution needs to be delayed through the zone > - * write plug. Otherwise, return false to let the submission path process > - * @bio normally. > + * Return %bzp_plugged if the @bio has been scheduled for delayed execution by > + * adding it to zwplug->bio_list; %bzp_failed if the caller should fail @bio or > + * %bzp_not_plugged to let the submission path process @bio normally. > */ > -bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) > +enum blk_zone_plug_status blk_zone_plug_bio(struct bio *bio, > + unsigned int nr_segs) > { > struct block_device *bdev = bio->bi_bdev; > > if (!bdev->bd_disk->zone_wplugs_hash) > - return false; > + return bzp_not_plugged; > > /* > * If the BIO already has the plugging flag set, then it was already > @@ -1065,7 +1060,7 @@ bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) > * plug bio submit work. > */ > if (bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING)) > - return false; > + return bzp_not_plugged; > > /* > * We do not need to do anything special for empty flush BIOs, e.g > @@ -1075,7 +1070,7 @@ bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) > * the written data. > */ > if (op_is_flush(bio->bi_opf) && !bio_sectors(bio)) > - return false; > + return bzp_not_plugged; > > /* > * Regular writes and write zeroes need to be handled through the target > @@ -1097,7 +1092,7 @@ bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) > switch (bio_op(bio)) { > case REQ_OP_ZONE_APPEND: > if (!bdev_emulates_zone_append(bdev)) > - return false; > + return bzp_not_plugged; > fallthrough; > case REQ_OP_WRITE: > case REQ_OP_WRITE_ZEROES: > @@ -1110,10 +1105,10 @@ bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) > case REQ_OP_ZONE_RESET_ALL: > return blk_zone_wplug_handle_reset_all(bio); > default: > - return false; > + return bzp_not_plugged; > } > > - return false; > + return bzp_not_plugged; > } > EXPORT_SYMBOL_GPL(blk_zone_plug_bio); > > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > index 39e5ffbf6d31..22f3ca58522d 100644 > --- a/include/linux/blkdev.h > +++ b/include/linux/blkdev.h > @@ -690,18 +690,27 @@ static inline bool blk_queue_is_zoned(struct request_queue *q) > (q->limits.features & BLK_FEAT_ZONED); > } > > +enum blk_zone_plug_status { > + bzp_not_plugged, > + bzp_plugged, > + bzp_wouldblock, > + bzp_failed, > +}; > + > #ifdef CONFIG_BLK_DEV_ZONED > static inline unsigned int disk_nr_zones(struct gendisk *disk) > { > return disk->nr_zones; > } > -bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs); > +enum blk_zone_plug_status blk_zone_plug_bio(struct bio *bio, > + unsigned int nr_segs); > #else /* CONFIG_BLK_DEV_ZONED */ > static inline unsigned int disk_nr_zones(struct gendisk *disk) > { > return 0; > } > -static inline bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) > +static inline enum blk_zone_plug_status blk_zone_plug_bio(struct bio *bio, > + unsigned int nr_segs) > { > return false; > }
diff --git a/block/blk-mq.c b/block/blk-mq.c index f4300e608ed8..2449f412dd00 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3095,8 +3095,20 @@ void blk_mq_submit_bio(struct bio *bio) if (blk_mq_attempt_bio_merge(q, bio, nr_segs)) goto queue_exit; - if (blk_queue_is_zoned(q) && blk_zone_plug_bio(bio, nr_segs)) - goto queue_exit; + if (blk_queue_is_zoned(q)) { + switch (blk_zone_plug_bio(bio, nr_segs)) { + case bzp_not_plugged: + break; + case bzp_plugged: + goto queue_exit; + case bzp_wouldblock: + bio_wouldblock_error(bio); + goto queue_exit; + case bzp_failed: + bio_io_error(bio); + goto queue_exit; + } + } new_request: if (rq) { diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 4b0be40a8ea7..cb2c05d8b1eb 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -675,8 +675,8 @@ static int disk_zone_sync_wp_offset(struct gendisk *disk, sector_t sector) disk_report_zones_cb, &args); } -static bool blk_zone_wplug_handle_reset_or_finish(struct bio *bio, - unsigned int wp_offset) +static enum blk_zone_plug_status +blk_zone_wplug_handle_reset_or_finish(struct bio *bio, unsigned int wp_offset) { struct gendisk *disk = bio->bi_bdev->bd_disk; sector_t sector = bio->bi_iter.bi_sector; @@ -684,10 +684,8 @@ static bool blk_zone_wplug_handle_reset_or_finish(struct bio *bio, unsigned long flags; /* Conventional zones cannot be reset nor finished. */ - if (!bdev_zone_is_seq(bio->bi_bdev, sector)) { - bio_io_error(bio); - return true; - } + if (!bdev_zone_is_seq(bio->bi_bdev, sector)) + return bzp_failed; /* * No-wait reset or finish BIOs do not make much sense as the callers @@ -713,10 +711,11 @@ static bool blk_zone_wplug_handle_reset_or_finish(struct bio *bio, disk_put_zone_wplug(zwplug); } - return false; + return bzp_not_plugged; } -static bool blk_zone_wplug_handle_reset_all(struct bio *bio) +static enum blk_zone_plug_status +blk_zone_wplug_handle_reset_all(struct bio *bio) { struct gendisk *disk = bio->bi_bdev->bd_disk; struct blk_zone_wplug *zwplug; @@ -739,7 +738,7 @@ static bool blk_zone_wplug_handle_reset_all(struct bio *bio) } } - return false; + return bzp_not_plugged; } static void disk_zone_wplug_schedule_bio_work(struct gendisk *disk, @@ -964,7 +963,8 @@ static bool blk_zone_wplug_prepare_bio(struct blk_zone_wplug *zwplug, return true; } -static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) +static enum blk_zone_plug_status +blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) { struct gendisk *disk = bio->bi_bdev->bd_disk; sector_t sector = bio->bi_iter.bi_sector; @@ -980,19 +980,15 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) * BIO-based devices, it is the responsibility of the driver to split * the bio before submitting it. */ - if (WARN_ON_ONCE(bio_straddles_zones(bio))) { - bio_io_error(bio); - return true; - } + if (WARN_ON_ONCE(bio_straddles_zones(bio))) + return bzp_failed; /* Conventional zones do not need write plugging. */ if (!bdev_zone_is_seq(bio->bi_bdev, sector)) { /* Zone append to conventional zones is not allowed. */ - if (bio_op(bio) == REQ_OP_ZONE_APPEND) { - bio_io_error(bio); - return true; - } - return false; + if (bio_op(bio) == REQ_OP_ZONE_APPEND) + return bzp_failed; + return bzp_not_plugged; } if (bio->bi_opf & REQ_NOWAIT) @@ -1001,10 +997,9 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) zwplug = disk_get_and_lock_zone_wplug(disk, sector, gfp_mask, &flags); if (!zwplug) { if (bio->bi_opf & REQ_NOWAIT) - bio_wouldblock_error(bio); + return bzp_wouldblock; else - bio_io_error(bio); - return true; + return bzp_failed; } /* Indicate that this BIO is being handled using zone write plugging. */ @@ -1022,22 +1017,21 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) if (!blk_zone_wplug_prepare_bio(zwplug, bio)) { spin_unlock_irqrestore(&zwplug->lock, flags); - bio_io_error(bio); - return true; + return bzp_failed; } zwplug->flags |= BLK_ZONE_WPLUG_PLUGGED; spin_unlock_irqrestore(&zwplug->lock, flags); - return false; + return bzp_not_plugged; plug: disk_zone_wplug_add_bio(disk, zwplug, bio, nr_segs); spin_unlock_irqrestore(&zwplug->lock, flags); - return true; + return bzp_plugged; } /** @@ -1048,16 +1042,17 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) * Handle write, write zeroes and zone append operations requiring emulation * using zone write plugging. * - * Return true whenever @bio execution needs to be delayed through the zone - * write plug. Otherwise, return false to let the submission path process - * @bio normally. + * Return %bzp_plugged if the @bio has been scheduled for delayed execution by + * adding it to zwplug->bio_list; %bzp_failed if the caller should fail @bio or + * %bzp_not_plugged to let the submission path process @bio normally. */ -bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) +enum blk_zone_plug_status blk_zone_plug_bio(struct bio *bio, + unsigned int nr_segs) { struct block_device *bdev = bio->bi_bdev; if (!bdev->bd_disk->zone_wplugs_hash) - return false; + return bzp_not_plugged; /* * If the BIO already has the plugging flag set, then it was already @@ -1065,7 +1060,7 @@ bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) * plug bio submit work. */ if (bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING)) - return false; + return bzp_not_plugged; /* * We do not need to do anything special for empty flush BIOs, e.g @@ -1075,7 +1070,7 @@ bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) * the written data. */ if (op_is_flush(bio->bi_opf) && !bio_sectors(bio)) - return false; + return bzp_not_plugged; /* * Regular writes and write zeroes need to be handled through the target @@ -1097,7 +1092,7 @@ bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) switch (bio_op(bio)) { case REQ_OP_ZONE_APPEND: if (!bdev_emulates_zone_append(bdev)) - return false; + return bzp_not_plugged; fallthrough; case REQ_OP_WRITE: case REQ_OP_WRITE_ZEROES: @@ -1110,10 +1105,10 @@ bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) case REQ_OP_ZONE_RESET_ALL: return blk_zone_wplug_handle_reset_all(bio); default: - return false; + return bzp_not_plugged; } - return false; + return bzp_not_plugged; } EXPORT_SYMBOL_GPL(blk_zone_plug_bio); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 39e5ffbf6d31..22f3ca58522d 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -690,18 +690,27 @@ static inline bool blk_queue_is_zoned(struct request_queue *q) (q->limits.features & BLK_FEAT_ZONED); } +enum blk_zone_plug_status { + bzp_not_plugged, + bzp_plugged, + bzp_wouldblock, + bzp_failed, +}; + #ifdef CONFIG_BLK_DEV_ZONED static inline unsigned int disk_nr_zones(struct gendisk *disk) { return disk->nr_zones; } -bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs); +enum blk_zone_plug_status blk_zone_plug_bio(struct bio *bio, + unsigned int nr_segs); #else /* CONFIG_BLK_DEV_ZONED */ static inline unsigned int disk_nr_zones(struct gendisk *disk) { return 0; } -static inline bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) +static inline enum blk_zone_plug_status blk_zone_plug_bio(struct bio *bio, + unsigned int nr_segs) { return false; }
The error handling code in blk_zone_plug_bio() and in the functions called by blk_zone_plug_bio() cannot be understood without knowing that these functions are only called by blk_mq_submit_bio(). Move the error handling code in blk_mq_submit_bio() such that all error handling code for blk_mq_submit_bio() occurs inside blk_mq_submit_bio() itself. Cc: Damien Le Moal <dlemoal@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- block/blk-mq.c | 16 ++++++++-- block/blk-zoned.c | 67 +++++++++++++++++++----------------------- include/linux/blkdev.h | 13 ++++++-- 3 files changed, 56 insertions(+), 40 deletions(-)