This patchset is the first stage of a two stage rewrite of the scsi
generic (sg) driver. The main goal of the first stage is to introduce
the sg v4 interface that uses 'struct sg_io_v4' as well as keeping and
modernizing the sg v3 interface (based on 'struct sg_io_hdr'). The
async interface formerly requiring the use of write() and read()
system calls now have ioctl(SG_IOSUBMIT) and ioctl(SG_IORECEIVE)
replacements.
For documentation see either url:
https://sg.danny.cz/sg/sg_v40.html
https://doug-gilbert.github.io/sg_v40.html
This patchset is against Martin Petersen's 5.14/scsi-queue branch.
Changes since v18 (sent to linux-scsi list on 20210407)
- a request queue's QUEUE_FLAG_POLL flag can be cleared via
sysfs, overriding the ability to use blk_poll() even when the
associated LLD allows it. Check that flag and, only when it
is set and the sg user gives SGV4_FLAG_HIPRI, set REQ_HIPRI
on a request.
- simplify the functions supporting ioctl(SG_SET_RESERVED_SIZE)
- replace blk_rq_append_bio() calls with the simpler
blk_rq_bio_prep() calls
[see lk: a4fe2d3afe3ce77edeadb567c0d0a8d102c6b159]
- rebase on 5.14/scsi-queue branch [lk 5.13-0-rc1]
- unchecked_isa_dma removed
- BIO_MAX_PAGES renamed to BIO_MAX_VECS
Changes since v17 (sent to linux-scsi list on 20210407)
- make clearer distinction between user pollable (i.e. async)
requests and (user) non-pollable requests (e.g. those injected
with ioctl(SG_IO), IOWs sync requests)
- fix crash is sg_start_req() when blk_get_request() yields an
error (e.g. -EAGAIN when low on resources)
- sg_finish_scsi_blk_rq(): remove now_zero variable as suggested
by Hannes R.
- change deprecation warning url reference from http to https
Changes since v16 (sent to linux-scsi list on 20210208)
- sg_start_req() fix double free on error path [KASAN]
- sg_rq_map_kern() fix uninitialized variable [coverity]
- sg_add_sfp() fix use after free [coverity]
- sg_remove_sfp_usercontext(): remove pointless NULL check [coverity]
- fix misuse of WARN_ONCE in sg_rq_end_io_usercontext() [D. Carpenter]
- remove unused error checks: tracking blk_put_request() calls and
multiple SG_XA_RQ_FREE calls
- hipri: as blk_poll() can return > 0 for requests other than the one
that is being checked for, need to re-check that request is ready
- rebased on MKP's 5.13/scsi-queue
Changes since v15 (sent to linux-scsi list on 20210125)
- tweak state machine which sets INFLIGHT state _before_
blk_execute_rq_nowait() is called. Add a bit flag that indicates
the logic flow has returned from that call. This guards against
blk_poll() being called before the block layer has really
launched the request.
- fix bug clearing SG_FFD_HIPRI_SEEN bit as
atomic_dec_and_test() returns true when the post-decrement value
is zero, the opposite of what a C conditional does.
Changes since v14 and earlier
- see: the v18 patchset sent to linux-scsi on 20210427
Douglas Gilbert (45):
sg: move functions around
sg: remove typedefs, type+formatting cleanup
sg: sg_log and is_enabled
sg: rework sg_poll(), minor changes
sg: bitops in sg_device
sg: make open count an atomic
sg: move header to uapi section
sg: speed sg_poll and sg_get_num_waiting
sg: sg_allow_if_err_recovery and renames
sg: improve naming
sg: change rwlock to spinlock
sg: ioctl handling
sg: split sg_read
sg: sg_common_write add structure for arguments
sg: rework sg_vma_fault
sg: rework sg_mmap
sg: replace sg_allow_access
sg: rework scatter gather handling
sg: introduce request state machine
sg: sg_find_srp_by_id
sg: sg_fill_request_element
sg: printk change %p to %pK
sg: xarray for fds in device
sg: xarray for reqs in fd
sg: replace rq array with xarray
sg: sense buffer rework
sg: add sg v4 interface support
sg: rework debug info
sg: add 8 byte SCSI LUN to sg_scsi_id
sg: expand sg_comm_wr_t
sg: add sg_iosubmit_v3 and sg_ioreceive_v3 ioctls
sg: add some __must_hold macros
sg: move procfs objects to avoid forward decls
sg: protect multiple receivers
sg: first debugfs support
sg: rework mmap support
sg: defang allow_dio
sg: warn v3 write system call users
sg: add mmap_sz tracking
sg: remove rcv_done request state
sg: track lowest inactive and await indexes
sg: remove unit attention check for device changed
sg: no_dxfer: move to/from kernel buffers
sg: add blk_poll support
sg: bump version to 4.0.12
drivers/scsi/sg.c | 5353 +++++++++++++++++++++++++++-------------
include/scsi/sg.h | 273 +-
include/uapi/scsi/sg.h | 375 +++
3 files changed, 4065 insertions(+), 1936 deletions(-)
create mode 100644 include/uapi/scsi/sg.h
--
2.25.1
