This version of scsi_target.c removes all SMP locking until
we have a lock-aware CAM stack. This allows us to use KNOTE
without a panic at least.
It's not yet clear whether target mode is working yet or not.
Discussed with: Scott, Ken, Nate, Justin
return to user space w/o waiting for I/O to complete.
I tried to get several folks who know this code better than me to review it
with no luck. I *do* know that w/o this code, using the SCSI target driver
panics in userret (if it doesn't panic in knote first).
an application to upon a tape (yea, even the non-control device) even if
it cannot establish a mount session. If the open cannot establish a mount
session and O_NONBLOCK was specified, the tape becomes 'open pending mount'.
All I/O operations that would require access to a tape thereafter until
a close attempt to initiate the mount session. If the mount session succeeds,
the tape driver transitions to full open state, else returns an appropriate
I/O error (ENXIO).
At the same time, add a change that remembers whether tape is being opened
read-only. If so, disallow 'write' operations like writing filemarks that
bypass the normal read-only filtering operations that happen in the write(2)
syscall.
Reviewed by: ken, justin, grog
MFC after: 2 weeks
Suggested by: The Bacula Team
operations before returning. Point the bus at a dummy cam_sim
structure so that any CCBs will complete immediately with a
CAM_DEV_NOT_THERE status, and ensure that any xpt_schedule() calls
on the bus's devices will immediately call the peripheral's
periph_start() routine. Also repeat the async messages because
devices that were part of the way through being probed may appear
after the original AC_LOST_DEVICE was sent, and would otherwise
never go away.
These changes make it possible to deregister a bus and free the SIM
at most stages during bus probing without the usual crashes in
camisr(). In particular, plugging in a umass device and then
unplugging it as soon as the first probe messages appeared would
almost always result in a crash. Now the device just goes away with
a few CAM errors and all references to the CAM bus, target and
device are dropped correctly.
CAM_LUN_INVALID or CAM_TID_INVALID. Retries were being triggered
here when a umass device was unplugged, and while the retries
themselves are probably harmless, they complicated finding the real
SIM removal problems.
the underlying drive had been hot-unplugged from the system. Here
is a specific example. Filesystem code had opened /dev/da1s1e.
Subsequently, the drive was hot-unplugged. This (correctly) caused
all of the associated /dev/da1* entries to be deleted. When the
filesystem later realized that the drive was gone it closed the
device, reducing the write-access counts to 0 on the geom providers
for da1s1e, da1s1, and da1. This caused geom to re-taste the
providers, resulting in the devices being created again. When the
drive was hot-plugged back in, it resulted in duplicate /dev entries
for da1s1e, da1s1, and da1.
This fix adds a new disk_gone() function which is called by CAM when a
drive goes away. It orphans all of the providers associated with the
drive, setting an error condition of ENXIO in each one. In addition,
we prevent a re-taste on last close for writing if an error condition
has been set in the provider.
Sponsored by: Isilon Systems
Reviewed by: phk
MFC after: 1 week
tunable (until we get REPORT LUNS in place).
If we're probing luns, and each probe succeeds, we keep going past
lun 7 if we're a SCSI3 or better device (until we fail to probe).
If we're probing luns, and a probe fails, we only keep going if
we're quirked *for* it (CAM_QUIRK_HILUNS), and if we're not quirked
*against* it (CAM_QUIRK_NOHILUNS), or we're a SCSI3 or better device
and the tunable (kern.cam.cam_srch_hi) is set non-zero.
Reviewed by: nate@rootlabs.org, gibbs@scsiguy.com, ken@kdm.com, scottl@samsco.org
MFC after: 1 week
event handler, dev_clone, which accepts a credential argument.
Implementors of the event can ignore it if they're not interested,
and most do. This avoids having multiple event handler types and
fall-back/precedence logic in devfs.
This changes the kernel API for /dev cloning, and may affect third
party packages containg cloning kernel modules.
Requested by: phk
MFC after: 3 days
- Introducing the possibility of using locks different than mutexes
for the knlist locking. In order to do this, we add three arguments to
knlist_init() to specify the functions to use to lock, unlock and
check if the lock is owned. If these arguments are NULL, we assume
mtx_lock, mtx_unlock and mtx_owned, respectively.
- Using the vnode lock for the knlist locking, when doing kqueue operations
on a vnode. This way, we don't have to lock the vnode while holding a
mutex, in filt_vfsread.
Reviewed by: jmg
Approved by: re (scottl), scottl (mentor override)
Pointyhat to: ssouhlal
Will be happy: everyone
module-specific malloc types. These should help us to pinpoint the
possible memory leakage in the future.
- Implementing xpt_alloc_ccb_nowait() and replacing all malloc/free based
CCB memory management with xpt_alloc_ccb[_nowait]/xpt_free_ccb. Hopefully
this would be helpful if someday we move the CCB allocator to use UMA
instead of malloc().
Encouraged by: jeffr, rwatson
Reviewed by: gibbs, scottl
Approved by: re (scottl)
(depends on how many memory you have) observed through "tar -tvf /dev/sa0."
Without this patch, RELENG_5 and HEAD panics with something like:
kmem_malloc(4096): kmem_map too small: 42258432 total allocated
RELENG_4 doesn't panic but spews following errors:
camq_init: - cannot malloc array!
Reviewed by: gibbs, scottl
Approved by: re (scottl)
MFC after: 3 days
period value. I suppose the BT adapter driver should be
fixed, but more importantly we should protect against
dividing by zero.
PR: kern/75603
MFC after: 1 week
succeed if there was no media in the drive.
This was broken in rev 1.72 when the media check was added to cdioctl().
For now, check the ioctl group to decide whether to check for media or not.
(We only need to check for media on CD-specific ioctls.)
Reported by: bland
MFC after: 3 days
disables tag queuing temporarily in order to allow controllers a window
to safely perform transfer negotiation with non-compliant devices. Before
this change, CAM would restore the queue depth to the controller specified
maximum or device quirk level rather than any depth determined by reactions
to QUEUE FULL/BUSY events or an explicit user setting.
During device probe, initialize the flags field for XPT_SCAN_BUS.
The uninitialized value often confused CAM into not bothering to
issue an AC_FOUND_DEVICE async event for new devices. The reason
this bug wasn't reported earlier is that CAM manually announces
devices after the initial system bus scans.
MFC: 3 days
Giant held. In camisr(), move the ccb_bioq elements to a temporary local list
and then process the elements off of that list. This enables the list to be
processed by only taking the ccb_bioq_lock once and only for a very short
time.
ccb_bioq_lock is a leaf mutex, so it's fine to call xpt_done() with other
locks held. This is just a very minor step in the work to lock CAM, but
it allows us to avoid some messy locking/unlock dances in certain drivers.
providing special version of CDIOCREADSUBCHANNEL ioctl(), which assumes that
result has to be placed into kernel space not user space. In the long run
more generic solution has to be designed WRT emulating various ioctl()s
that operate on userspace buffers, but right now there is only one such
ioctl() is emulated, so that it makes little sense.
MFC after: 2 weeks
It reports itself as SCSI-3 but doesnt like getting probed on high luns
because it hangs hard after finding itself again on lun 32...
Suggested by: Kenneth Merry
