linux.git/Documentation/block, branch master Linux kernel source tree Documentation: ublk: address review comments for SHMEM_ZC docs 2026-04-10T01:10:44+00:00 Ming Lei tom.leiming@gmail.com 2026-04-09T13:30:18+00:00 289653bb76c46149f88939c3cfef55cdb236ace2 - Use "physical pages" instead of "page frame numbers (PFNs)" for clarity - Remove "without any per-I/O overhead" claim from zero-copy description - Add scatter/gather limitation: each I/O's data must be contiguous within a single registered buffer Suggested-by: Caleb Sander Mateos <csander@purestorage.com> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Link: https://patch.msgid.link/20260409133020.3780098-7-tom.leiming@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> 
- Use "physical pages" instead of "page frame numbers (PFNs)" for
  clarity
- Remove "without any per-I/O overhead" claim from zero-copy
  description
- Add scatter/gather limitation: each I/O's data must be contiguous
  within a single registered buffer

Suggested-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260409133020.3780098-7-tom.leiming@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
ublk: enable UBLK_F_SHMEM_ZC feature flag 2026-04-07T13:39:24+00:00 Ming Lei ming.lei@redhat.com 2026-03-31T15:31:54+00:00 08677040a91199175149d1fd465c02e3b3fc768a Add UBLK_F_SHMEM_ZC (1ULL << 19) to the UAPI header and UBLK_F_ALL. Switch ublk_support_shmem_zc() and ublk_dev_support_shmem_zc() from returning false to checking the actual flag, enabling the shared memory zero-copy feature for devices that request it. Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://patch.msgid.link/20260331153207.3635125-4-ming.lei@redhat.com [axboe: ublk_buf_reg -> ublk_shmem_buf_reg errors] Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Add UBLK_F_SHMEM_ZC (1ULL << 19) to the UAPI header and UBLK_F_ALL.
Switch ublk_support_shmem_zc() and ublk_dev_support_shmem_zc() from
returning false to checking the actual flag, enabling the shared
memory zero-copy feature for devices that request it.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://patch.msgid.link/20260331153207.3635125-4-ming.lei@redhat.com
[axboe: ublk_buf_reg -> ublk_shmem_buf_reg errors]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-crypto: fix name of the bio completion callback 2026-04-02T13:09:03+00:00 Christoph Hellwig hch@lst.de 2026-04-01T13:58:51+00:00 4e56428ed4782e9e1356875af8e714b24c5a8783 Fix a simple naming issue in the documentation: the completion routine is called bi_end_io and not bi_complete. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Eric Biggers <ebiggers@kernel.org> Link: https://patch.msgid.link/20260401135854.125109-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Fix a simple naming issue in the documentation: the completion
routine is called bi_end_io and not bi_complete.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Link: https://patch.msgid.link/20260401135854.125109-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: remove bio_last_bvec_all 2026-01-27T04:07:48+00:00 Keith Busch kbusch@kernel.org 2026-01-26T16:27:24+00:00 72a41750f1a35b46caa5bbd70df7b5d3ce4f4b0a There are no more callers of this function after commit f6b2d8b134b2413 ("btrfs: track the next file offset in struct btrfs_bio_ctrl"), so remove the function. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> 
There are no more callers of this function after commit f6b2d8b134b2413
("btrfs: track the next file offset in struct btrfs_bio_ctrl"), so
remove the function.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
ublk: document feature UBLK_F_BATCH_IO 2026-01-23T03:05:40+00:00 Ming Lei ming.lei@redhat.com 2026-01-16T14:18:45+00:00 4d8fd7c5592acc2cc89b1759fb01171478c9ee5f Document feature UBLK_F_BATCH_IO. Reviewed-by: Caleb Sander Mateos <csander@purestorage.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Document feature UBLK_F_BATCH_IO.

Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-crypto: handle the fallback above the block layer 2026-01-11T19:55:41+00:00 Christoph Hellwig hch@lst.de 2026-01-09T06:07:49+00:00 bb8e2019ad613dd023a59bf91d1768018d17e09b Add a blk_crypto_submit_bio helper that either submits the bio when it is not encrypted or inline encryption is provided, but otherwise handles the encryption before going down into the low-level driver. This reduces the risk from bio reordering and keeps memory allocation as high up in the stack as possible. Note that if the submitter knows that inline enctryption is known to be supported by the underyling driver, it can still use plain submit_bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Add a blk_crypto_submit_bio helper that either submits the bio when
it is not encrypted or inline encryption is provided, but otherwise
handles the encryption before going down into the low-level driver.
This reduces the risk from bio reordering and keeps memory allocation
as high up in the stack as possible.

Note that if the submitter knows that inline enctryption is known to
be supported by the underyling driver, it can still use plain
submit_bio.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Documentation: ublk: Separate UBLK_F_AUTO_BUF_REG fallback behavior sublists 2025-06-13T15:25:42+00:00 Bagas Sanjaya bagasdotme@gmail.com 2025-06-13T02:38:57+00:00 db3dfae1a2f662e69d535827703bcdbb04b8d72b Stephen Rothwell reports htmldocs warning on ublk docs: Documentation/block/ublk.rst:414: ERROR: Unexpected indentation. [docutils] Fix the warning by separating sublists of auto buffer registration fallback behavior from their appropriate parent list item. Fixes: ff20c516485e ("ublk: document auto buffer registration(UBLK_F_AUTO_BUF_REG)") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/linux-next/20250612132638.193de386@canb.auug.org.au/ Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20250613023857.15971-1-bagasdotme@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Stephen Rothwell reports htmldocs warning on ublk docs:

Documentation/block/ublk.rst:414: ERROR: Unexpected indentation. [docutils]

Fix the warning by separating sublists of auto buffer registration
fallback behavior from their appropriate parent list item.

Fixes: ff20c516485e ("ublk: document auto buffer registration(UBLK_F_AUTO_BUF_REG)")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20250612132638.193de386@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20250613023857.15971-1-bagasdotme@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
ublk: document auto buffer registration(UBLK_F_AUTO_BUF_REG) 2025-06-11T12:41:55+00:00 Ming Lei ming.lei@redhat.com 2025-06-11T08:56:32+00:00 ff20c516485efbeb5c32bcb6aa5a24f73774185b Document recently merged feature auto buffer registration(UBLK_F_AUTO_BUF_REG). Cc: Caleb Sander Mateos <csander@purestorage.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250611085632.109719-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Document recently merged feature auto buffer registration(UBLK_F_AUTO_BUF_REG).

Cc: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250611085632.109719-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Documentation: ublk: document UBLK_F_PER_IO_DAEMON 2025-05-31T20:38:57+00:00 Uday Shankar ushankar@purestorage.com 2025-05-29T23:47:18+00:00 08652bd86e267b0c83ed013dd972c99c04c7e76a Explain the restrictions imposed on ublk servers in two cases: 1. When UBLK_F_PER_IO_DAEMON is set (current ublk_drv) 2. When UBLK_F_PER_IO_DAEMON is not set (legacy) Remove most references to per-queue daemons, as the new UBLK_F_PER_IO_DAEMON feature renders that concept obsolete. Signed-off-by: Uday Shankar <ushankar@purestorage.com> Reviewed-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250529-ublk_task_per_io-v8-9-e9d3b119336a@purestorage.com Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Explain the restrictions imposed on ublk servers in two cases:
1. When UBLK_F_PER_IO_DAEMON is set (current ublk_drv)
2. When UBLK_F_PER_IO_DAEMON is not set (legacy)

Remove most references to per-queue daemons, as the new
UBLK_F_PER_IO_DAEMON feature renders that concept obsolete.

Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250529-ublk_task_per_io-v8-9-e9d3b119336a@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Documentation: ublk: remove dead footnote 2025-03-31T13:06:22+00:00 Jens Axboe axboe@kernel.dk 2025-03-31T13:06:22+00:00 f28a71bc979392234cc110cd1e6787fb5b432116 A previous commit removed the use of this footnote, delete it. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 3fdf2ec7da1c ("Documentation: ublk: Drop Stefan Hajnoczi's message footnote") Signed-off-by: Jens Axboe <axboe@kernel.dk> 
A previous commit removed the use of this footnote, delete it.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 3fdf2ec7da1c ("Documentation: ublk: Drop Stefan Hajnoczi's message footnote")
Signed-off-by: Jens Axboe <axboe@kernel.dk>