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| author | Christoph Hellwig <hch@lst.de> | 2024-06-17 08:04:40 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-06-19 07:58:28 -0600 |
| commit | 1122c0c1cc71f740fa4d5f14f239194e06a1d5e7 (patch) | |
| tree | 690fcda48991904d6916c6f6e0f2205e37511531 /arch/um | |
| parent | 70905f8706b62113ae32c8df721384ff6ffb6c6a (diff) | |
| download | lwn-1122c0c1cc71f740fa4d5f14f239194e06a1d5e7.tar.gz lwn-1122c0c1cc71f740fa4d5f14f239194e06a1d5e7.zip | |
block: move cache control settings out of queue->flags
Move the cache control settings into the queue_limits so that the flags
can be set atomically with the device queue frozen.
Add new features and flags field for the driver set flags, and internal
(usually sysfs-controlled) flags in the block layer. Note that we'll
eventually remove enough field from queue_limits to bring it back to the
previous size.
The disable flag is inverted compared to the previous meaning, which
means it now survives a rescan, similar to the max_sectors and
max_discard_sectors user limits.
The FLUSH and FUA flags are now inherited by blk_stack_limits, which
simplified the code in dm a lot, but also causes a slight behavior
change in that dm-switch and dm-unstripe now advertise a write cache
despite setting num_flush_bios to 0. The I/O path will handle this
gracefully, but as far as I can tell the lack of num_flush_bios
and thus flush support is a pre-existing data integrity bug in those
targets that really needs fixing, after which a non-zero num_flush_bios
should be required in dm for targets that map to underlying devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index cdcb75a68989..19e01691ea0e 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -835,6 +835,7 @@ static int ubd_add(int n, char **error_out) struct queue_limits lim = { .max_segments = MAX_SG, .seg_boundary_mask = PAGE_SIZE - 1, + .features = BLK_FEAT_WRITE_CACHE, }; struct gendisk *disk; int err = 0; @@ -882,7 +883,6 @@ static int ubd_add(int n, char **error_out) } blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); - blk_queue_write_cache(disk->queue, true, false); disk->major = UBD_MAJOR; disk->first_minor = n << UBD_SHIFT; disk->minors = 1 << UBD_SHIFT; |