[PATCH v3 0/3] nvme_map_user_request() cleanup
Caleb Sander Mateos
csander at purestorage.com
Mon Mar 24 13:05:37 PDT 2025
The first commit removes a WARN_ON_ONCE() checking userspace values.
The last 2 move code out of nvme_map_user_request() that belongs better
in its callers, and move the fixed buffer import before going async.
As discussed in [1], this allows an NVMe passthru operation submitted at
the same time as a ublk zero-copy buffer unregister operation to succeed
even if the initial issue goes async. This can improve performance of
userspace applications submitting the operations together like this with
a slow fallback path on failure. This is an alternate approach to [2],
which moved the fixed buffer import to the io_uring layer.
There will likely be conflicts with the parameter cleanup series Keith
posted last month in [3].
The series is based on block/for-6.15/io_uring, with commit 00817f0f1c45
("nvme-ioctl: fix leaked requests on mapping error") cherry-picked.
[1]: https://lore.kernel.org/io-uring/20250321184819.3847386-1-csander@purestorage.com/T/#u
[2]: https://lore.kernel.org/io-uring/20250321184819.3847386-4-csander@purestorage.com/
[3]: https://lore.kernel.org/all/20250224182128.2042061-1-kbusch@meta.com/T/#u
v3: Move the fixed buffer import before allocating a blk-mq request
v2: Fix iov_iter value passed to nvme_map_user_request()
Caleb Sander Mateos (3):
nvme/ioctl: don't warn on vectorized uring_cmd with fixed buffer
nvme/ioctl: move blk_mq_free_request() out of nvme_map_user_request()
nvme/ioctl: move fixed buffer lookup to nvme_uring_cmd_io()
drivers/nvme/host/ioctl.c | 68 +++++++++++++++++++++------------------
1 file changed, 36 insertions(+), 32 deletions(-)
--
2.45.2
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