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. See:
http://sg.danny.cz/sg/sg_v40.html
for more details.
Due to changes in the production sg driver (mainly due to
compat_ioctl() work) there are many changes in this patchset just
keeping up. Significant changes appeared in lk 5.5.3 with more
in lk 5.6.0-rc1. This patchset is build on the latter.
The complete patchset, whose second stage has an additional 25 patches
(i.e. 63 patches in all), can be found soon at the above link.
Changes since v7 (sent to linux-scsi list on 20200227)
- improve direct IO code, remove the SG_FRQ_DIO_IN_USE
sg_request::frq_bm flag as it is no longer needed
- simplify state changing code. Many state changes (rq_st) do not
need changes to the xarray "marks"; only lock those that do
(reviewer queried the locking)
- remove some misplaced likely()/unlikely() macros. They are gathered
together in a separate patch (in a second patchset)
- change a cast that the kbuild robot complained about. It also
flagged a stack size problem in sg_ioctl_common() for reasons not
given nor obvious. That function (and its parents) declare only
simple scalars on the stack.
- add 'Reviewed-by' where appropriate
Changes since v6 (sent to linux-scsi list on 20200112)
- based on Martin Petersen's 5.7/scsi-queue branch in his
linux-scsi repository
- major work on mmap support: when mmap(2) is used the reserve
request scatter gather list is rebuilt to have order=0
elements (i.e. each is PAGE_SIZE bytes).
- address one kbuild robot issue: add include defining size_t
- nearly all patches that have been reviewed have been changed,
usually in minor ways. Those patches have "***" before the
"Reviewed-by" line.
Changes since v5 (sent to linux-scsi list on 20191008)
- replace linked lists with xarray mechanism
- use the locking in the xarray implementation to
replace several discrete locks
- some patches that were previously reviewed by
Hannes Reinecke have had small changes made to
them usually associated with xarrays. Those have
been marked with "***" prepended to the
"Reviewed-by" line
- bump the driver version number to 4.0.08
Changes since v4 (sent to linux-scsi list on 20190829)
- remove much of the logic in the previous patchset
series from and including:
[PATCH v4 11/22] sg: replace rq array with lists
to
[PATCH v4 22/22] sg: bump version to 4.0.03
- bump the driver version number from 3.5.36 to 3.9.01
[20190606] reflecting that the v4 interface has not
been implemented (in this patchset)
- patches 13/23 through to 22/23 reduce the complexity
of "[PATCH v4 11/22] sg: replace rq array with lists"
measured in KiloBytes from about 130 KB to 80 KB.
- various changes suggested by reviewers of the v4
patchset have been implemented
- change all %p descriptors (mainly in SG_LOG() macros)
to %pK so that the debug output remains useful in
recent kernels. Evidently sys admins can selectively
turn on pointer obfuscation on %pK as required on
secure systems.
Changes since v3 (sent to linux-scsi list on 20190807):
- move __must_hold attributes into separate patch
- move procfs and debugfs file scope definitions toward
the end of sg.c to avoid forward declarations
- move module_param* and MODULE_* macros to end of sg.c
- expand debugfs support with snapshot_devs which allows
filtering of snapshot output by sg device(s)
- add a WARN_ONCE when write(2) is used with the sg v3
interface. Suggest using SG_IOSUBMIT_V3 instead.
- address more of the review comments from Hannes Reinecke
and Christoph Hellwig
- add various reviewed-by tags where appropriate
Changes since v2 (sent to linux-scsi list on 20190727):
- address issues "Reported-by: kbuild test robot <lkp@xxxxxxxxx>".
The main one was to change the bsg header included to:
include/uapi/linux/bsg.h rather than include/linux/bsg.h
- address some of the review comments from Hannes Reinecke;
email responses have been sent for review comments that
did not result in code changes
Changes since v1 (sent to linux-scsi list on 20190616):
- change ktime_get_boot_ns() to ktime_get_boottime_ns() to reflect
kernel API change first seen in lk 5.3.0-rc1
Douglas Gilbert (38):
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 lists
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: warn v3 write system call users
sg: bump version to 4.0.08
drivers/scsi/sg.c | 5173 +++++++++++++++++++++++++++-------------
include/scsi/sg.h | 270 +--
include/uapi/scsi/sg.h | 374 +++
3 files changed, 3909 insertions(+), 1908 deletions(-)
create mode 100644 include/uapi/scsi/sg.h
--
2.25.1
