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.
This patchset is against Martin Petersen's 5.8/scsi-queue branch.
There are some fixes for the original sg driver that are working
their way through various lk 5.7.* and earlier trees that may
upset this patchset. All those fixes (and several others) are
already fixed in this series.
Changes since v8 (sent to linux-scsi list on 20200301)
- add new patch to ignore the /proc/scsi/sg/allow_dio setting.
Now direct IO will be attempted whenever the SG_FLAG_DIRECT_IO
flag is given
- add new patch to track mmap_sz from previous mmap() call.
Allows catching mmap-ed requests that exceed that value
- change warning about using the v3 interface with the write()
system call from WARN_ONCE() to pr_warn_once()
- remove __KERNEL__ conditionals in include/scsi/sg.h
- change struct sg_fd::start_ns from u64 to ktime_t type
- introduce a new small sg_rq_state_mul2arr array to avoid
a multiplication at runtime in the state machine engine
- tweak mempool introduced in v7 for sense buffers
- rework sg_mk_sgat() to better handle low memory situations;
similar work on sg_remove_sgat_helper()
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 (40):
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: defang allow_dio
sg: warn v3 write system call users
sg: add mmap_sz tracking
sg: bump version to 4.0.09
drivers/scsi/sg.c | 5183 +++++++++++++++++++++++++++-------------
include/scsi/sg.h | 273 +--
include/uapi/scsi/sg.h | 374 +++
3 files changed, 3917 insertions(+), 1913 deletions(-)
create mode 100644 include/uapi/scsi/sg.h
--
2.26.1
