When transport_lookup_tmr_lun() fails and we return a task management
response from target_complete_tmr_failure(), we need to call
transport_cmd_check_stop_to_fabric() to release the last ref to the
cmd after calling se_tfo->queue_tm_rsp(), or else we will never remove
the failed TMR from the session command list (and we'll end up waiting
forever when trying to tear down the session).
(nab: Fix minor compile breakage)
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
If a backend IO takes a really long then an initiator might abort a
command, and then when it gives up on the abort, send a LUN reset too,
all before we process any of the original command or the abort. (The
abort will wait for the backend IO to complete too)
When the backend IO final completes (or fails), the abort handling
will proceed and queue up a "return aborted status" operation. Then,
while that's still pending, the LUN reset might find the original
command still on the LUN's list of commands and try to return aborted
status again, which leads to a use-after free when the first
se_tfo->queue_status call frees the command and then the second
se_tfo->queue_status call runs.
Fix this by removing a command from the LUN state_list when we first
are about to queue aborted status; we shouldn't do anything
LUN-related after we've started returning status, so this seems like
the correct thing to do.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes a regression bug introduced during v3.6.x code with
the following commit to drop transport_add_cmd_to_queue(), which
originally re-set CMD_T_ACTIVE during pending WRITE I/O submission:
commit af8772926f
Author: Christoph Hellwig <hch@infradead.org>
Date: Sun Jul 8 15:58:49 2012 -0400
target: replace the processing thread with a TMR work queue
The following sequence happens for write commands (or any other
commands with a data out phase):
- The transport calls target_submit_cmd(), which sets CMD_T_ACTIVE in
cmd->transport_state and sets cmd->t_state to TRANSPORT_NEW_CMD.
- Things go on transport_generic_new_cmd(), which notices that the
command needs to transfer data, so it sets cmd->t_state to
TRANSPORT_WRITE_PENDING and calls transport_cmd_check_stop().
- transport_cmd_check_stop() clears CMD_T_ACTIVE in cmd->transport_state
and returns in the normal case.
- Then we continue on to call ->se_tfo->write_pending().
- The data comes back from the initiator, and the transport calls
target_execute_cmd(), which sets cmd->t_state to TRANSPORT_PROCESSING
and calls into the backend to actually write the data.
At this point, the backend might take a long time to complete the
command, since it has to do real IO. If an abort request comes in for
this command at this point, it will not wait for the command to finish
since CMD_T_ACTIVE is not set. Then when the command does finally
finish, we blow up with use-after-free.
Avoid this by setting CMD_T_ACTIVE in target_execute_cmd() so that
transport_wait_for_tasks() waits for the command to finish executing.
This matches the behavior from before commit 1389533ef9 ("target:
remove transport_generic_handle_data"), when data was signaled via
transport_generic_handle_data(), which set CMD_T_ACTIVE because it
called transport_add_cmd_to_queue().
Signed-off-by: Roland Dreier <roland@purestorage.com>
Reported-by: Martin Svec <martin.svec@zoner.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Introduce TCM_NO_SENSE, mapping to sense code
'Not ready, no additional sense information'.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Nicholas Bellinger <nab@risingtidesystems.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The ASC/ASCQ code for 'Logical Unit Communication failure' is
0x08/0x00; 0x80/0x00 is vendor specific.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Nicholas Bellinger <nab@risingtidesystems.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Pull target updates from Nicholas Bellinger:
"It has been a very busy development cycle this time around in target
land, with the highlights including:
- Kill struct se_subsystem_dev, in favor of direct se_device usage
(hch)
- Simplify reservations code by combining SPC-3 + SCSI-2 support for
virtual backends only (hch)
- Simplify ALUA code for virtual only backends, and remove left over
abstractions (hch)
- Pass sense_reason_t as return value for I/O submission path (hch)
- Refactor MODE_SENSE emulation to allow for easier addition of new
mode pages. (roland)
- Add emulation of MODE_SELECT (roland)
- Fix bug in handling of ExpStatSN wrap-around (steve)
- Fix bug in TMR ABORT_TASK lookup in qla2xxx target (steve)
- Add WRITE_SAME w/ UNMAP=0 support for IBLOCK backends (nab)
- Convert ib_srpt to use modern target_submit_cmd caller + drop
legacy ioctx->kref usage (nab)
- Convert ib_srpt to use modern target_submit_tmr caller (nab)
- Add link_magic for fabric allow_link destination target_items for
symlinks within target_core_fabric_configfs.c code (nab)
- Allocate pointers in instead of full structs for
config_group->default_groups (sebastian)
- Fix 32-bit highmem breakage for FILEIO (sebastian)
All told, hch was able to shave off another ~1K LOC by killing the
se_subsystem_dev abstraction, along with a number of PR + ALUA
simplifications. Also, a nice patch by Roland is the refactoring of
MODE_SENSE handling, along with the addition of initial MODE_SELECT
emulation support for virtual backends.
Sebastian found a long-standing issue wrt to allocation of full
config_group instead of pointers for config_group->default_group[]
setup in a number of areas, which ends up saving memory with big
configurations. He also managed to fix another long-standing BUG wrt
to broken 32-bit highmem support within the FILEIO backend driver.
Thank you again to everyone who contributed this round!"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (50 commits)
target/iscsi_target: Add NodeACL tags for initiator group support
target/tcm_fc: fix the lockdep warning due to inconsistent lock state
sbp-target: fix error path in sbp_make_tpg()
sbp-target: use simple assignment in tgt_agent_rw_agent_state()
iscsi-target: use kstrdup() for iscsi_param
target/file: merge fd_do_readv() and fd_do_writev()
target/file: Fix 32-bit highmem breakage for SGL -> iovec mapping
target: Add link_magic for fabric allow_link destination target_items
ib_srpt: Convert TMR path to target_submit_tmr
ib_srpt: Convert I/O path to target_submit_cmd + drop legacy ioctx->kref
target: Make spc_get_write_same_sectors return sector_t
target/configfs: use kmalloc() instead of kzalloc() for default groups
target/configfs: allocate only 6 slots for dev_cg->default_groups
target/configfs: allocate pointers instead of full struct for default_groups
target: update error handling for sbc_setup_write_same()
iscsit: use GFP_ATOMIC under spin lock
iscsi_target: Remove redundant null check before kfree
target/iblock: Forward declare bio helpers
target: Clean up flow in transport_check_aborted_status()
target: Clean up logic in transport_put_cmd()
...
No need to have a goto where a return is clearer.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@risingtidesystems.com>
v2: Use correct target_core_stat.c 2006 copyright year
v3: Drop extra unnessary legal verbage from header (hch)
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
- If we stop processing an already-aborted command in
target_execute_cmd(), then we need to complete t_transport_stop_comp
to wake up the the TMR handling thread, or else it will end up
waiting forever.
- If we've a already sent an "aborted" status for a command in
transport_check_aborted_status() then we should bail out of
transport_send_task_abort() to avoid freeing the command twice.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@risingtidesystems.com>
This patch fixes a possible case in transport_generic_new_cmd() where a
failure from TFO->write_pending() from a fabric module return something
other than -EAGAIN or -ENOMEM would cause a failed WRITE to silently
succeed.
Go ahead and return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE for this
special case instead of only just making noise with WARN_ON().
(v2: Fix incorrect exception return for all cases)
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Pass the sense reason as an explicit return value from the I/O submission
path instead of storing it in struct se_cmd and using negative return
values. This cleans up a lot of the code pathes, and with the sparse
annotations for the new sense_reason_t type allows for much better
error checking.
(nab: Convert spc_emulate_modesense + spc_emulate_modeselect to use
sense_reason_t with Roland's MODE SELECT changes)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We always support ALUA for virtual backends, and never for physical ones. Simplify
the code to just deal with these two cases and remove the superflous abstractions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We do not support host-level reservations for the pscsi backend, and all
virtual backends are newere than SCSI-2, so just make the combined
SPC-3 + SCSI-2 support the only supported variant and kill the switches
for the different implementations, given that this code handles the no-op
version just fine.
(hch: Update DRF_SPC2_RESERVATIONS lock usage)
Signed-off-by: Christoph Hellwig <hch@lst.de>
We can just key off ordered tag emulation of the transport_type field.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
drivers/target/target_core_pscsi.c:464:5: sparse: symbol 'pscsi_configure_device'
was not declared. Should it be static?
FYI, there are new sparse warnings show up in
tree: git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending.git queue
head: 738b86ac5e56c645aa5b7bf49cb38e2a04c665f8
commit: 410aeee637c47bcf7e8dd7893347fe0811e07ab1 [47/51] target: kill struct se_subsystem_dev
vim +464 drivers/target/target_core_pscsi.c
410aeee6 Christoph Hellwig 2012-10-08 @464 int pscsi_configure_device(struct se_device *dev)
c66ac9db Nicholas Bellinger 2010-12-17 465 {
410aeee6 Christoph Hellwig 2012-10-08 466 struct se_hba *hba = dev->se_hba;
410aeee6 Christoph Hellwig 2012-10-08 467 struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
c66ac9db Nicholas Bellinger 2010-12-17 468 struct scsi_device *sd;
410aeee6 Christoph Hellwig 2012-10-08 469 struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
c66ac9db Nicholas Bellinger 2010-12-17 470 struct Scsi_Host *sh = phv->phv_lld_host;
c66ac9db Nicholas Bellinger 2010-12-17 471 int legacy_mode_enable = 0;
410aeee6 Christoph Hellwig 2012-10-08 472 int ret;
Please consider folding the attached diff :-)
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Simplify the code a lot by killing the superflous struct se_subsystem_dev.
Instead se_device is allocated early on by the backend driver, which allocates
it as part of its own per-device structure, borrowing the scheme that is for
example used for inode allocation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Fabric drivers currently expect to internally release se_cmd in the event
of a TMR failure during target_submit_tmr(), which means the immediate call
to transport_generic_free_cmd() after TFO->queue_tm_rsp() from within
target_complete_tmr_failure() workqueue context is wrong.
This is done as some fabrics expect TMR operations to be acknowledged
before releasing the descriptor, so the assumption that core is releasing
se_cmd associated TMR memory is incorrect. This fixes a OOPs where
transport_generic_free_cmd() was being called more than once.
This bug was originally observed with tcm_qla2xxx fabric ports.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch carries forward a work-around from tcm_loop to target
core code to explicitly clear control CDB READ paylods in order to
avoid bugs in scsi-generic user-space code for INQUIRY that do not
explicitly zero CDB payload memory.
(v2: Drop TARGET_SCF_MAP_CLEAR_MEM, and perform the explicit zero
of READ memory for all target_submit_cmd_map_sgls users)
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch adds a new target_submit_cmd_map_sgls() to pass pre-allocated
SGL memory using transport_generic_map_mem_to_cmd() logic into the generic
target submit I/O codepath.
It also adds a target_submit_cmd() wrapper around target_submit_cmd_map_sgls()
for existing fabric code that already assumes internal target-core SGL memory
allocation.
(v2: Rename to target_submit_cmd_map_sgls + drop TARGET_SCF_MAP_MEM flag
in favor of non zero sgl_count check)
Reported-by: Christoph Hellwig <hch@lst.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Yay, all users of transport_kmap_data_sg now check for a zero-length
request and/or a too-small parameter list length. We can thus go through
the normal emulation path even for such commands.
This means that out-of-bounds reads and writes are now reported correctly
even if they transfer 0 blocks. Other errors are also reported correctly.
Testcase: sg_raw /dev/sdb 28 00 80 00 00 00 00 00 00 00
should fail with ILLEGAL REQUEST / LBA OUT OF RANGE sense
does not fail without the patch
(still wrong with the patch, but better: the ASC is INVALID FIELD IN CDB)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Correct spelling typo in printk and comment within drivers/target.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Every fabric driver has to supply a se_tfo->set_fabric_sense_len()
method, just so iSCSI can return an offset of 2. However, every fabric
driver is already allocating a sense buffer and passing it into the
target core, either via transport_init_se_cmd() or target_submit_cmd().
So instead of having iSCSI pass the start of its sense buffer into the
core and then later tell the core to skip the first 2 bytes, it seems
easier for iSCSI just to do the offset of 2 when it passes the sense
buffer into the core. Then we can drop the se_tfo->set_fabric_sense_len()
everywhere, and just add a couple of lines of code to iSCSI to set the
sense data length to the beginning of the buffer right before it sends
it over the network.
(nab: Remove .set_fabric_sense_len usage from tcm_qla2xxx_npiv_ops +
change transport_get_sense_buffer to follow v3.6-rc6 code w/o
->set_fabric_sense_len usage)
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Move static into function body from file scope.
Remove extraneous return statement
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Now that spc_emulate_request_sense has been taught to process zero-length
REQUEST SENSE correctly, drop the special handling of unit attention
conditions from transport_generic_new_cmd. However, for now REQUEST SENSE
will be the only command that goes through emulation for zero lengths.
(nab: Fix up zero-length check in transport_generic_new_cmd)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
In order to support zero-size allocation lengths, do not assert
that we have a scatterlist until after checking cmd->data_length.
But once we do this, we can have two cases of transport_kmap_data_sg
returning NULL: a zero-size allocation length, or an out-of-memory
condition. Report the latter using sense codes, so that the SCSI
command that triggered it will fail.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Right now, commands with a zero-size payload are skipped completely.
This is wrong; such commands should be passed down to the device and
processed normally.
For physical backends, this ignores completely things such as START
STOP UNIT. For virtual backends, we have a hack in place to clear a
unit attention state on a zero-size REQUEST SENSE, but we still do
not report errors properly on zero-length commands---out-of-bounds
0-block reads and writes, too small parameter list lengths, etc.
This patch fixes this for PSCSI. Uses of transport_kmap_data_sg are
guarded with a check for non-zero cmd->data_length; for all other
commands a zero length is handled properly in pscsi_execute_cmd.
The sole exception will be for now REPORT LUNS, which is handled
through the normal SPC emulation.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The pointer to the sense buffer is fetched by transport_get_sense_data,
but this is called by target_complete_ok_work long after pscsi_req_done
has freed the struct that contains it.
Pass instead the fabric's sense buffer to transport_complete,
and copy the data to it directly in transport_complete. Setting
SCF_TRANSPORT_TASK_SENSE also becomes a duty of transport_complete.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The error conditions in transport_get_sense_data are superfluous
and complicate the code unnecessarily:
* SCF_TRANSPORT_TASK_SENSE is checked in the caller;
* it's simply part of the invariants of dev->transport->get_sense_buffer
that it must be there if transport_complete ever returns 1, and that
it must not return NULL. Besides, the entire callback will disappear
with the next patch.
* similarly in the caller we can expect that sense data is only sent
for non-zero cmd->scsi_status.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We will be calling it from transport_complete_cmd, avoid forward
declarations. No semantic change.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes a long-standing bug with SCSI overflow handling
where se_cmd->data_length was incorrectly being re-assigned to
the larger CDB extracted allocation length, resulting in a number
of fabric level errors that would end up causing a session reset
in most cases. So instead now:
- Only re-assign se_cmd->data_length durining UNDERFLOW (to use the
smaller value)
- Use existing se_cmd->data_length for OVERFLOW (to use the smaller
value)
This fix has been tested with the following CDB to generate an
SCSI overflow:
sg_raw -r512 /dev/sdc 28 0 0 0 0 0 0 0 9 0
Tested using iscsi-target, tcm_qla2xxx, loopback and tcm_vhost fabric
ports. Here is a bit more detail on each case:
- iscsi-target: Bug with open-iscsi with overflow, sg_raw returns
-3584 bytes of data.
- tcm_qla2xxx: Working as expected, returnins 512 bytes of data
- loopback: sg_raw returns CHECK_CONDITION, from overflow rejection
in transport_generic_map_mem_to_cmd()
- tcm_vhost: Same as loopback
Reported-by: Roland Dreier <roland@purestorage.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This was originally for helping fabrics to determine overflow/underflow
status, and has been superceeded by SCF_OVERFLOW_BIT + SCF_UNDERFLOW_BIT.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes a regression bug with the handling of zero-length
data CDBs within transport_generic_new_cmd() code. The bug was introduced
with the following commit as part of the single task conversion work:
commit 4101f0a89d
Author: Christoph Hellwig <hch@infradead.org>
Date: Tue Apr 24 00:25:03 2012 -0400
target: always allocate a single task
where the zero-length check for SCF_SCSI_DATA_SG_IO_CDB was incorrectly
changed to SCF_SCSI_CONTROL_SG_IO_CDB because of the seperate comment
in transport_generic_new_cmd() wrt to control CDBs zero-length handling
introduced in:
commit 91ec1d3535
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Fri Jan 13 12:01:34 2012 -0800
target: Add workaround for zero-length control CDB handling
So go ahead and change transport_generic_new_cmd() to handle control+data
zero-length CDBs in the same manner for this special case.
Tested with iscsi-target + loopback fabric port LUNs on 3.6-rc0 code.
This patch will also need to be picked up for 3.5-stable.
(hch: Add proper comment in transport_generic_new_cmd)
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
I am hitting this bug when the target is low in memory that fails the
alloc_page() for the newly submitted command. This is a sort of off-by-one
bug causing NULL pointer dereference in __free_page() since 'i' here is
really the counter of total pages that have been successfully allocated here.
Signed-off-by: Yi Zou <yi.zou@intel.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Open-FCoE.org <devel@open-fcoe.org>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
During a failure in transport_add_device_to_core_hba() code, we called
destroy_workqueue(dev->tmr_wq) before ->tmr_wq was allocated which leads
to an oops.
This fixes a regression introduced in with:
commit af8772926f
Author: Christoph Hellwig <hch@infradead.org>
Date: Sun Jul 8 15:58:49 2012 -0400
target: replace the processing thread with a TMR work queue
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We want it to be possible for target_submit_cmd() to return errors up
to its fabric module callers. For now just update the prototype to
return an int, and update all callers to handle non-zero return values
as an error.
This is immediately useful for tcm_qla2xxx to fix a long-standing active
I/O session shutdown race, but tcm_fc, usb-gadget, and sbp-target the
fabric maintainers need to check + ACK that handling a target_submit_cmd()
failure due to session shutdown does not introduce regressions
(nab: Respin against for-next after initial NACK + update docbook comment +
fix double se_cmd init in exception path for usb-gadget)
Cc: Chad Dupuis <chad.dupuis@qlogic.com>
Cc: Arun Easi <arun.easi@qlogic.com>
Cc: Chris Boot <bootc@bootc.net>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Mark Rustad <mark.d.rustad@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Many SCSI commands are defined to return a CHECK CONDITION / ILLEGAL
REQUEST with ASC set to LOGICAL BLOCK ADDRESS OUT OF RANGE if the
initiator sends a command that accesses a too-big LBA. Add an enum
value and case entries so that target code can return this status.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Since we set se_session.sess_tearing_down and stop new commands from
being added to se_session.sess_cmd_list before we wait for commands to
finish when freeing a session, there's no need for a separate
sess_wait_list -- if we let new commands be added to sess_cmd_list
after setting sess_tearing_down, that would be a bug that breaks the
logic of waiting in-flight commands.
Also rename target_splice_sess_cmd_list() to
target_sess_cmd_list_set_waiting(), since we are no longer splicing
onto a separate list.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Target core code assumes that target_splice_sess_cmd_list() has set
sess_tearing_down and moved the list of pending commands to
sess_wait_list, no more commands will be added to the session; if any
are added, nothing keeps the se_session from being freed while the
command is still in flight, which e.g. leads to use-after-free of
se_cmd->se_sess in target_release_cmd_kref().
To enforce this invariant, put a check of sess_tearing_down inside of
sess_cmd_lock in target_get_sess_cmd(); any checks before this are
racy and can lead to the use-after-free described above. For example,
the qla_target check in qlt_do_work() checks sess_tearing_down from
work thread context but then drops all locks before calling
target_submit_cmd() (as it must, since that is a sleeping function).
However, since no locks are held, anything can happen with respect to
the session it has looked up -- although it does correctly get
sess_kref within its lock, so the memory won't be freed while
target_submit_cmd() is actually running, nothing stops eg an ACL from
being dropped and calling ->shutdown_session() (which calls into
target_splice_sess_cmd_list()) before we get to target_get_sess_cmd().
Once this happens, the se_session memory can be freed as soon as
target_submit_cmd() returns and qlt_do_work() drops its reference,
even though we've just added a command to sess_cmd_list.
To prevent this use-after-free, check sess_tearing_down inside of
sess_cmd_lock right before target_get_sess_cmd() adds a command to
sess_cmd_list; this is synchronized with target_splice_sess_cmd_list()
so that every command is either waited for or not added to the queue.
(nab: Keep target_submit_cmd() returning void for now..)
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
There are no in-tree users of target_get_sess_cmd() outside of
target_core_transport.c. Any new code should use the higher-level
target_submit_cmd() interface. So let's un-export target_get_sess_cmd()
and make it static to the one file where it's actually used.
(nab: Fix up minor fuzz to for-next)
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The last functionality of the target processing thread is offloading possibly
long running task management requests from the submitter context. To keep
TMR semantics the same we need a single threaded ordered queue, which can
be provided by a per-device workqueue with the right flags.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Remove this command submission path which is not used by any in-tree driver.
This also removes the now unused new_cmd_map fabtric method, which a few
drivers implemented despite never calling transport_generic_handle_cdb_map.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
There is no need to schedule the delayed processing in a workqueue that
offloads it to the target processing thread. Instead execute it directly
from the workqueue. There will be a lot of future work in this area,
which I'd likfe to defer for now as it is not nessecary for getting rid
of the target processing thread.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
When we call target_execute_cmd for write commands the command has been
on the state list before an abort might have come in before
target_execute_cmd. Call transport_check_aborted_status to deal with
this case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Just call target_execute_cmd directly. Also, convert loopback, sbp,
usb-gadget to use the newly exported target_execute_cmd().
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Inline the transport_off == 0 case into target_execute_cmd to simplify
the function for the remaining cases.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Remove the execute_cmd method in struct se_subsystem_api, and always use the
one directly in struct se_cmd. To make life simpler for SBC virtual backends
a struct spc_ops that is passed to sbc_parse_cmd is added. For now it
only contains an execute_rw member, but more will follow with the subsequent
commits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
