With the recent changes in the CAM error handling, some problems in
the error handling of sa(4) have been uncovered. Basically, a number
of conditions that are not actually errors have been mistreated as
genuine errors. In particular:
. Trying to read in variable length mode with a mismatched blocksize
between the on-tape (virtual) blocks and the read(2) supplied buffer
size, causing an ILI SCSI condition, have caused an attempt to retry
the supposedly `errored' transfer, causing the tape to be read
continuously until it eventually hit EOM. Since by default any
simple mt(1) operation does an initial test read, an `mt stat' was
sufficient to trigger this bug.
Note that it's Justin's opinion that treating a NO SENSE as an EIO
is another bug in CAM. I feel not authorized to fix cam_periph.c
without another confirmation that i'm on the right track, however.
. Hitting a filemark caused the read(2) syscall to return EIO, instead
of returning a `short read'. Note that the current fix only solves
this problem in variable length mode. Fixed length mode uses a
different code path, and since i didn't grok all the intentions behind
that handling, i did not touch it (IOW: it's still broken, and you get
an EIO upon hitting a filemark).
The solution is to keep track of those conditions inside saerror(),
and upon completion to not call cam_periph_error() in that case. We
need to make sure that the device gets unfrozen if needed though (in
case of actual errors, cam_periph_error() does this on our behalf).
Not objected by: mjacob (who currently doesn't have the time to
review the patch)
semantics don't: in practice, both policy and semantics permit
loop-back debugging operations, only it's just a subset of debugging
operations (i.e., a proc can open its own /dev/mem), and that's at a
higher layer.
This is will be required to prevent lowering the ipl when a critical_enter()
is present in the interrupt path when handling a machine check.
reviewed by: jhb
only aiod does this and is also marked P_SYSTEM, the locations that
reference p->p_vmspace usually do it within the context of the caller,
the async access from the vm system is protected by the fact that it
will skip over P_SYSTEM processes.
Ok'd by: jhb
means that the pcic98 functionality might now work (I've tested it on
my pcic machine, but not the pcic98). Since these functions are
rarely called, it is unlikely that this will have a measurable impact
on performance.
FreeBSD. This code doesn't work just yet, but does compile. We need
to start indirecting via the cinfo pointers, rather than directly
calling pcic_*. There may be other issues as well, but you gotta
start somewhere.
Obtained from: PAO3
we also reserve _adequate_ space for the mb_map submap; i.e. we need
space for nmbclusters, nmbufs, _and_ nmbcnt. Furthermore, we need to
rounddown, and not roundup, so that we are consistent.
Pointed out by: bde
Also move the insertion of the request to after the request is validated,
there's still looks like there may be some problems if an invalid address
is passed to the aio routines, basically a possible leak or having a
not completely initialized structure on the queue may still be possible.
A new sig macro was made _SIG_VALID to check the validity of a signal,
it would be advisable to use it from now on (in kern/kern_sig.c) rather
than rolling your own.
PR: kern/17152
Protect pager object list manipulation with a mutex.
It doesn't look possible to combine them under a single sx lock because
creation may block and we can't have the object list manipulation block
on anything other than a mutex because of interrupt requests.
available.
Only directory vnodes holding no child directory vnodes held in
v_cache_src are recycled, so that directory vnodes near the root of
the filesystem hierarchy remain in namecache and directory vnodes are
not reclaimed in cascade.
The period of vnode reclaiming attempt and the number of vnodes
attempted to reclaim can be tuned via sysctl(2).
Suggested by: tegge
Approved by: phk
