In a fully-preemptible realtime kernel (CONFIG_PREEMPT_RT_FULL=y),
SCSI commands from an initiator time out because the userland target
application is never woken to process them.
This is because in a fully-preemptible realtime kernel, soft-IRQ
(tasklet) execution always occurs in a ksoftirqd thread and
preempt_count is not manipulated on soft-IRQ processing entry/exit.
This makes in_interrupt() useless for determining whether soft-IRQ
processing is occurring; instead, in_serving_softirq() should be
used for that purpose.
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
[bvanassche: Elaborated source code comment]
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5272 d57e44dd-8a1f-0410-8b47-8ef2f437770f
The sysfs API is supported from kernel 2.6.26 on and uses the swap()
macro while the swap() macro was introduced in kernel 2.6.29. Hence
provide a definition of the swap() macro for kernels before 2.6.29.
Signed-off-by: Sebastian Herbszt <herbszt@gmx.de>
[bvanassche: Moved swap() definition a few lines down and added #ifndef/#endif]
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5269 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Avoid that disabling a target triggers a race condition with
SRP relogin. At least in theory this race condition could result
in a kernel crash.
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5268 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Coverity warns that sgv may be used uninitialized. The warning
applies to WRITE SAME commands with LBDATA == PBDATA == 0 (replicate
a single block of user data into the specified LBA range).
The warning appears to be spurious - when LBDATA == PBDATA == 0,
scst_ws_write_cmd_finished() will not use the uninitialized value
saved by scst_ws_push_single_write().
Move initialization of sgv earlier in the function to quiesce the warning.
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5266 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Avoid that scst_local triggers "BUG: unable to handle kernel NULL
pointer dereference" on kernel versions before 2.6.37. This patch
fixes a regression introduced via patch "scst_local: Avoid
deadlock during module removal with kernel 3.6" (trunk r4566).
Reported-by: Sebastian Herbszt <herbszt@gmx.de>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5264 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Since the time during which a PR read or write lock is held is short,
use a mutex to implement PR read and write locking. So although this
patch excludes multiple simultaneous readers that shouldn't affect the
time needed to process a PR operation measurably.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5254 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Although it is possible to obtain these statistics by iterating over
all sessions and by computing the sum of the per-target statistics,
make per-target statistics directly available such that these can be
retrieved easily.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5249 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Avoid that sparse reports the following warning:
warning: 'prot_usage' may be used uninitialized in this function
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5227 d57e44dd-8a1f-0410-8b47-8ef2f437770f
The libfc implementation can handle long SG lists, hence increase
ft_scst_template.sg_tablesize from 128 to 65535.
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5223 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Kernel versions before 2.6.26 do not have a definition for the
ACCESS_ONCE() macro, hence provide one.
Signed-off-by: Sebastian Herbszt <herbszt@gmx.de>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5220 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Reduce the number of reservation state variables from (one per
device + one per session) to one per device. Introduce helper
functions for manipulating the SPC-2 reservation state.
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5218 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Bart Van Assche
Vladislav Bolkhovitin