Instead of leaving it implicit that SAM_STAT_GOOD == 0, compare explicitly
with SAM_STAT_GOOD.
Link: https://lore.kernel.org/r/20210415220826.29438-18-bvanassche@acm.org
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Make data_pages_per_blk changeable similar to the way it is done for
max_data_area_mb. One can change the value by typing:
echo "data_pages_per_blk=N" >control
The value is printed when doing:
cat info
In addition, a new readonly attribute 'data_pages_per_blk' returns the
value on read.
Link: https://lore.kernel.org/r/20210324195758.2021-7-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Replace DATA_PAGES_PER_BLK and DATA_BLOCK_SIZE with new struct elements
tcmu_dev->data_pages_per_blk and tcmu_dev->data_blk_size. These new
variables are still loaded with constant definition DATA_PAGES_PER_BLK_DEF
(= 1) and DATA_PAGES_PER_BLK_DEF * PAGE_SIZE.
There is no way yet to set the values via configfs.
Link: https://lore.kernel.org/r/20210324195758.2021-6-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There is only one caller of tcmu_get_block_page left. Since it is a
one-liner, we can remove the function.
Link: https://lore.kernel.org/r/20210324195758.2021-5-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Change tcmu to support DATA_BLOCK_SIZE being a multiple of PAGE_SIZE. There
are two reasons why one would like to have a bigger DATA_BLOCK_SIZE:
1) If userspace - e.g. due to data compression, encryption or
deduplication - needs to have receive or transmit data in a consecutive
buffer, we can define DATA_BLOCK_SIZE to the maximum size of a SCSI
READ/WRITE to enforce that userspace sees just one consecutive
buffer. That way we can avoid the need for doing data copy in
userspace.
2) Using a bigger data block size can speed up command processing in
tcmu. The number of free data blocks to look up in bitmap is reduced
substantially. The lookup for data pages in radix_tree can be done more
efficiently if there are multiple pages in a data block. The maximum
number of IOVs to set up is lower so cmd entries in the ring become
smaller.
Link: https://lore.kernel.org/r/20210324195758.2021-4-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Rename some variables and definitions as a first preparation for
DATA_BLOCK_SIZE != PAGE_SIZE and add the new DATA_PAGES_PER_BLK definition
containing the number of pages per data block.
Rename tcmu_try_get_block_page() to tcmu_try_get_data_page(). Keep name
tcmu_get_block_page() since it will go away in a following commit when
there is only one caller left. Subsequent commits will then add full
support for DATA_PAGES_PER_BLK != 1, which also means DATA_BLOCK_SIZE =
DATA_PAGES_PER_BLK * PAGE_SIZE
Link: https://lore.kernel.org/r/20210324195758.2021-3-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Some definitions and members of struct tcmu_dev had misleading
names. Examples:
- ring_size was used for the size of mailbox + cmd ring + data area
- CMDR_SIZE was used for size of mailbox + cmd ring
I added the new definition MB_CMDR_SIZE (mailbox + command ring), changed
CMDR_SIZE to hold the size of the command ring only and replaced in struct
tcmu_dev the member ring_size with mmap_pages, because the member is now
used in tcmu_mmap() only, where we need page count, not size.
I also added the new struct tcmu_dev member 'cmdr' which is used to replace
some occurences of '(void *)mb + CMDR_OFF' with 'udev->cmdr' for better
readability.
Link: https://lore.kernel.org/r/20210324195758.2021-2-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Resolve a couple of conflicts between the 5.12 fixes branch and the
5.13 staging tree (iSCSI target and UFS).
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Create the device for the virtual LUN 0 using the DUMMY flag. This change
makes it possible to remove some special-casing in the INQUIRY code.
Link: https://lore.kernel.org/r/20210322200938.53300-3-k.shelekhin@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit adds the DUMMY flag to the rd_mcp backend that forces a logical
unit to report itself as not connected device of an unknown type.
Essentially this allows users to create devices identical to the device for
the virtual LUN 0, making it possible to explicitly create a LUN 0 device
and configure its WWNs (e.g. vendor or product name).
Link: https://lore.kernel.org/r/20210322200938.53300-2-k.shelekhin@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
target_sequencer_start event is triggered inside target_cmd_init_cdb().
se_cmd.tag is not initialized with ITT at the moment so the event always
prints zero tag.
Link: https://lore.kernel.org/r/20210403215415.95077-1-r.bolshakov@yadro.com
Cc: stable@vger.kernel.org # 5.10+
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Pull 5.12/scsi-fixes into the 5.13 SCSI tree to provide a baseline for
some UFS changes that would otherwise cause conflicts during the
merge.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
If pscsi_map_sg() fails, make sure to drop references to already allocated
bios.
Link: https://lore.kernel.org/r/20210323212431.15306-2-mwilck@suse.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
pscsi_map_sg() uses the variable nr_pages as a hint for bio_kmalloc() how
many vector elements to allocate. If nr_pages is < BIO_MAX_PAGES, it will
be reset to 0 after successful allocation of the bio.
If bio_add_pc_page() fails later for whatever reason, pscsi_map_sg() tries
to allocate another bio, passing nr_vecs = 0. This causes bio_add_pc_page()
to fail immediately in the next call. pci_map_sg() continues to allocate
zero-length bios until memory is exhausted and the kernel crashes with
OOM. This can be easily observed by exporting a SATA DVD drive via pscsi.
The target crashes as soon as the client tries to access the DVD LUN. In
the case I analyzed, bio_add_pc_page() would fail because the DVD device's
max_sectors_kb (128) was exceeded.
Avoid this by simply not resetting nr_pages to 0 after allocating the
bio. This way, the client receives an I/O error when it tries to send
requests exceeding the devices max_sectors_kb, and eventually gets it
right. The client must still limit max_sectors_kb e.g. by an udev rule if
(like in my case) the driver doesn't report valid block limits, otherwise
it encounters I/O errors.
Link: https://lore.kernel.org/r/20210323212431.15306-1-mwilck@suse.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Fix warning:
drivers/target/target_core_transport.c:1661: WARNING: Block quote ends
without a blank line; unexpected unindent.
Link: https://lore.kernel.org/r/20210318225858.11863-1-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In commit f7c89771d0 ("scsi: target: tcmu: Replace radix_tree with
XArray") the meaning of last parameter of tcmu_blocks_release() was
changed. So in the callers we should subtract 1 from the previous
parameter.
Unfortunately that change got lost at one of the two places where
tcmu_blocks_release() is called. That does not lead to any problems, but we
should adjust it anyway.
Link: https://lore.kernel.org/r/20210310184458.10741-1-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The function fd_do_prot_fill() is called from two callers
fd_do_prot_unmap() and fd_format_prot(). Both callers initialize the passed
buffer to 0xff with memset().
Move the memset() call to fd_do_prot_fill() to avoid duplication.
Link: https://lore.kernel.org/r/20210228055645.22253-24-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Remove unused macro to fix the following compilation warning:
drivers/target//iscsi/iscsi_target_util.c:31: warning: macro "PRINT_BUFF" is not used [-Wunused-macros]
#define PRINT_BUFF(buff, len) \
Link: https://lore.kernel.org/r/20210228055645.22253-12-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Remove unused macro to fix the following compilation warning:
drivers/target//iscsi/iscsi_target_nego.c:31: warning: macro "TEXT_LEN" is not used [-Wunused-macros]
#define TEXT_LEN 4096
Link: https://lore.kernel.org/r/20210228055645.22253-11-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Remove unused macro to fix the following compilation warning:
drivers/target//iscsi/iscsi_target_stat.c:31: warning: macro "ISCSI_INST_LAST_FAILURE_TYPE" is not used [-Wunused-macros]
#define ISCSI_INST_LAST_FAILURE_TYPE 0
Link: https://lore.kernel.org/r/20210228055645.22253-10-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Remove the unuseds macro to fix the following compilation warnings:
drivers/target//target_core_stat.c:34: warning: macro "NONE" is not used [-Wunused-macros]
#define NONE "None"
drivers/target//iscsi/iscsi_target_stat.c:36: warning: macro "ISPRINT" is not used [-Wunused-macros]
#define ISPRINT(a) ((a >= ' ') && (a <= '~'))
Link: https://lore.kernel.org/r/20210228055645.22253-8-chaitanya.kulkarni@wdc.com
Link: https://lore.kernel.org/r/20210228055645.22253-9-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Rename function local variable i to sg_cnt so we can get rid of the
shadow variable compilation warning:
unsigned int i;
^
int i;
^
Link: https://lore.kernel.org/r/20210228055645.22253-6-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Remove unused macro to fix the following compilation warning:
drivers/target//target_core_pscsi.c:37: warning: macro "ISPRINT" is not used [-Wunused-macros]
#define ISPRINT(a) ((a >= ' ') && (a <= '~'))
Link: https://lore.kernel.org/r/20210228055645.22253-7-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This fixes a compilation warning in pscsi_complete_cmd():
drivers/target/target_core_pscsi.c: In function ‘pscsi_complete_cmd’:
drivers/target/target_core_pscsi.c:624:5: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
Link: https://lore.kernel.org/r/20210228055645.22253-5-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
According to ilog2() it expects 32/64 bit unsigned value.
" 147 * ilog2 - log base 2 of 32-bit or a 64-bit unsigned value"
Replace type of logs_per_phys from int to unsigned int.
Link: https://lore.kernel.org/r/20210228055645.22253-4-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Trim the line that is longer than 80 characters, which is inconsistent with
the rest of the code.
Link: https://lore.kernel.org/r/20210228055645.22253-3-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The two arguments to the functions op and opf which are REQ_OP_XXX and
REQ_XXX flags belong to the two different namespaces, i.e. they can be
combined safely given that REQ_OP_XXX takes 8 bits of the flags and rest is
available to REQ_XXX flags.
Replace op and op_flag arguments with opf.
Link: https://lore.kernel.org/r/20210228055645.22253-2-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Especially when using tcmu with tcm_loop, memory allocations with
GFP_KERNEL for a LUN can cause write back to the same LUN.
So we have to use GFP_NOIO when allocation is done while handling commands
or while holding cmdr_lock.
Link: https://lore.kernel.org/r/20210305190009.32242-1-bostroesser@gmail.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
An attempt from Matthew Wilcox to replace radix-tree usage by XArray in
tcmu more than 1 year ago unfortunately got lost.
I rebased that work on latest tcmu and tested it.
Link: https://lore.kernel.org/r/20210224185335.13844-3-bostroesser@gmail.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
An attempt from Matthew Wilcox to replace IDR usage by XArray in tcmu more
than 1 year ago unfortunately got lost.
I rebased that work on latest tcmu and tested it.
Link: https://lore.kernel.org/r/20210224185335.13844-2-bostroesser@gmail.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
It may not always be best to complete the IO on same CPU as it was
submitted on. This commit allows userspace to configure it.
This has been useful for vhost-scsi where we have a single thread for
submissions and completions. If we force the completion on the submission
CPU we may be adding conflicts with what the user has setup in the lower
levels with settings like the block layer rq_affinity or the driver's IRQ
or softirq (the network's rps_cpus value) settings.
We may also want to set it up where the vhost thread runs on CPU N and does
its submissions/completions there, and then have LIO do its completion
booking on CPU M, but can't configure the lower levels due to issues like
using dm-multipath with lots of paths (the path selector can throw commands
all over the system because it's only taking into account latency/throughput
at its level).
The new setting is in:
/sys/kernel/config/target/$fabric/$target/param/cmd_completion_affinity
Writing:
-1 -> Gives the current default behavior of completing on the
submission CPU.
-2 -> Completes the cmd on the CPU the lower layers sent it to us from.
> 0 -> Completes on the CPU userspace has specified.
Link: https://lore.kernel.org/r/20210227170006.5077-26-michael.christie@oracle.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
If a cmd is on the submission workqueue then the TMR code will miss it, and
end up returning task not found or success for LUN resets. The fabric
driver might then tell the initiator that the running cmds have been
handled when they are about to run.
This adds a flush when we are processing TMRs to make sure queued cmds do
not run after returning the TMR response.
Link: https://lore.kernel.org/r/20210227170006.5077-25-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch adds plug/unplug callouts for tcmu, so we can avoid the number
of times we switch to userspace. Using this driver with tcm_loop is a
common config, and dependng on the nr_hw_queues (nr_hw_queues=1 performs
much better) and fio jobs (lower num jobs around 4) this patch can increase
IOPS by only around 5-10% because we hit other issues like the big per tcmu
device mutex.
Link: https://lore.kernel.org/r/20210227170006.5077-24-michael.christie@oracle.com
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch adds plug/unplug callouts for iblock. For an initiator driver
like iSCSI which wants to pass multiple cmds to its xmit thread instead of
one cmd at a time, this increases IOPS by around 10% with vhost-scsi
(combined with the last patches we can see a total 40-50% increase). For
driver combos like tcm_loop and faster drivers like the iSER initiator, we
can still see IOPS increase by 20-30% when tcm_loop's nr_hw_queues setting
is also increased.
Link: https://lore.kernel.org/r/20210227170006.5077-23-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
target_core_iblock is plugging and unplugging on every command and this is
causing perf issues for drivers that prefer batched cmds. With recent
patches we can now take multiple cmds from a fabric driver queue and then
pass them down the backend drivers in a batch. This patch adds this support
by adding 2 callouts to the backend for plugging and unplugging the
device. Subsequent commits will add support for iblock and tcmu device
plugging.
Link: https://lore.kernel.org/r/20210227170006.5077-22-michael.christie@oracle.com
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Convert loop to use the LIO wq cmd submission helper.
Link: https://lore.kernel.org/r/20210227170006.5077-20-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Make tcm_loop use the block layer cmd allocator for se_cmds instead of
using the tcm_loop_cmd_cache. In the future when we can use the host tags
for internal requests like TMFs we can completely kill the
tcm_loop_cmd_cache.
Link: https://lore.kernel.org/r/20210227170006.5077-19-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
loop and vhost/scsi do their target cmd submission from driver
workqueues. This allows them to avoid an issue where the backend may block
waiting for resources like tags/requests, mem/locks, etc and that ends up
blocking their entire submission path and for the case of vhost-scsi both
the submission and completion path.
This patch adds a helper drivers can use to submit from a LIO workqueue.
This code will then be extended in the next patches to fix the plugging of
backend devices.
We are only converting vhost/loop initially, but the workqueue based
submission will work for other drivers and have similar benefits where the
main target loops will not end up blocking one some backend resource.
Link: https://lore.kernel.org/r/20210227170006.5077-17-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
tcm_loop could be used like a normal block device, so we can't use
GFP_KERNEL and should use GFP_NOIO. This adds a gfp_t arg to
target_cmd_init_cdb() and converts the users. For every driver but loop
GFP_KERNEL is kept.
This will also be useful in subsequent patches where loop needs to do
target_submit_prep() from interrupt context to get a ref to the se_device,
and so it will need to use GFP_ATOMIC.
Link: https://lore.kernel.org/r/20210227170006.5077-16-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Convert target_submit_cmd() to do its own calls and then remove
target_submit_cmd_map_sgls() since no one uses it.
Link: https://lore.kernel.org/r/20210227170006.5077-15-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
target_submit_cmd() is now only for simple drivers that do their own sync
during shutdown and do not use target_stop_session().
tcm_fc uses target_stop_session() to sync session shutdown with LIO core,
so we use target_init_cmd(), target_submit_prep(), target_submit(), because
target_init_cmd() will now detect the target_stop_session() call and return
an error.
Link: https://lore.kernel.org/r/20210227170006.5077-14-michael.christie@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
target_submit_cmd() is now only for simple drivers that do their own sync
during shutdown and do not use target_stop_session(). It will never return
a failure, so we can remove that code from the driver.
Link: https://lore.kernel.org/r/20210227170006.5077-10-michael.christie@oracle.com
Cc: Chris Boot <bootc@bootc.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
target_submit_cmd_map_sgls() is being removed, so convert loop to
the new submission API.
Even though loop does its own shutdown sync, this has loop use
target_init_cmd()/target_submit_prep()/target_submit() since it needed to
map sgls and in the next patches it will use the API to use LIO's
workqueue.
Link: https://lore.kernel.org/r/20210227170006.5077-9-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This breaks up target_submit_cmd_map_sgls() into 3 helpers:
- target_init_cmd(): Do the basic general setup and get a refcount to the
session to make sure the caller can execute the cmd.
- target_submit_prep(): Do the mapping, cdb processing and get a ref to
the LUN.
- target_submit(): Pass the cmd to LIO core for execution.
The above functions must be used by drivers that either:
1. Rely on LIO for session shutdown synchronization by calling
target_stop_session().
2. Need to map sgls.
When the next patches are applied then simple drivers that do not need the
extra functionality above can use target_submit_cmd() and not worry about
failures being returned and how to handle them, since many drivers were
getting this wrong and would have hit refcount bugs.
Also, by breaking target_submit_cmd_map_sgls() up into these 3 helper
functions, we can allow the later patches to do the init/prep from
interrupt context and then do the submission from a workqueue.
Link: https://lore.kernel.org/r/20210227170006.5077-5-michael.christie@oracle.com
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Nilesh Javali <njavali@marvell.com>
Cc: Michael Cyr <mikecyr@linux.ibm.com>
Cc: Chris Boot <bootc@bootc.net>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Rename transport_init_se_cmd() to __target_init_cmd() to reflect that it is
more of an internal function that drivers should normally not use and
because we are going to add a new init function in the next patches.
Link: https://lore.kernel.org/r/20210227170006.5077-4-michael.christie@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The kref_get_unless_zero() use in target_get_sess_cmd() was added in:
commit 1b4c59b7a1 ("target: fix potential race window in
target_sess_cmd_list_waiting()")'
but it does not seem to do anything.
The original patch might have thought we could have added the cmd to the
sess_wait_list and then target_wait_for_sess_cmds could do a put before
target_get_sess_cmd did its get. That wouldn't happen because we do the get
first then grab the sess lock and put it on the list.
It is also not needed now, because the sess_cmd_list does not exist anymore
and we instead wait on the session cmd_count.
The other problem with the commit is that several
target_submit_cmd_map_sgls()/target_submit_cmd() callers do not handle the
error case properly if it were to ever happen. These drivers think they
have their normal refcount on the cmd and in many cases do a
transport_generic_free_cmd() plus target_put_sess_cmd() so they would have
fired off the refcount WARN/BUGs.
This patch just changes the kref_get_unless_zero() to kref_get().
Link: https://lore.kernel.org/r/20210227170006.5077-3-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Prepare to split target_submit_cmd_map_sgls() so the initialization and
submission part can be called at different times. If the init part fails we
can reference the t_task_cdb early in some of the logging and tracing
code. Move it to transport_init_se_cmd() so we don't hit NULL pointer
crashes.
Link: https://lore.kernel.org/r/20210227170006.5077-2-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
