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| author | Mike Snitzer <snitzer@kernel.org> | 2024-04-11 22:08:05 +0300 |
|---|---|---|
| committer | Mike Snitzer <snitzer@kernel.org> | 2024-04-23 18:19:56 +0300 |
| commit | 7560680c8d1e810826d048a61d35668541dce038 (patch) | |
| tree | 02e95ee5a280b36d78316c1dfad87a06d2ca1202 /drivers/md | |
| parent | 2285e1496dc68787a626145cfb0904a1b6cc5501 (diff) | |
| download | linux-7560680c8d1e810826d048a61d35668541dce038.tar.xz | |
dm-crypt: stop constraining max_segment_size to PAGE_SIZE
This change effectively reverts commit 586b286b110e ("dm crypt:
constrain crypt device's max_segment_size to PAGE_SIZE") and relies on
block core's late bio-splitting to ensure that dm-crypt's encryption
bios are split accordingly if they exceed the underlying device's
limits (e.g. max_segment_size).
Commit 586b286b110e was applied as a 4.3 fix for the benefit of
stable@ kernels 4.0+ just after block core's late bio-splitting was
introduced in 4.3 with commit 54efd50bfd873 ("block: make
generic_make_request handle arbitrarily sized bios"). Given block
core's late bio-splitting it is past time that dm-crypt make use of
it.
Also, given the recent need to revert meaningful progress that was
attempted during the 6.9 merge window (see commit bff4b74625fe Revert
"dm: use queue_limits_set") this change allows DM core to safely make
use of queue_limits_set() without risk of breaking dm-crypt on NVMe.
Though it should be noted this commit isn't a prereq for reinstating
DM core's use of queue_limits_set() because blk_validate_limits() was
made less strict with commit b561ea56a264 ("block: allow device to
have both virt_boundary_mask and max segment size").
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-crypt.c | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 5bfa35760167..f43a2c0b3d77 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1656,8 +1656,8 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); /* * Generate a new unfragmented bio with the given size - * This should never violate the device limitations (but only because - * max_segment_size is being constrained to PAGE_SIZE). + * This should never violate the device limitations (but if it did then block + * core should split the bio as needed). * * This function may be called concurrently. If we allocate from the mempool * concurrently, there is a possibility of deadlock. For example, if we have @@ -3717,14 +3717,6 @@ static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) { struct crypt_config *cc = ti->private; - /* - * Unfortunate constraint that is required to avoid the potential - * for exceeding underlying device's max_segments limits -- due to - * crypt_alloc_buffer() possibly allocating pages for the encryption - * bio that are not as physically contiguous as the original bio. - */ - limits->max_segment_size = PAGE_SIZE; - limits->logical_block_size = max_t(unsigned int, limits->logical_block_size, cc->sector_size); limits->physical_block_size = |