After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.
To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.
Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
nlmsg_multicast now takes an extra allocation flag, so add it to
the use in the fibre channel transport class.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch adds the following functionality to the FC transport:
- dev_loss_tmo LLDD callback :
Called to essentially confirm the deletion of an rport. Thus, it is
called whenever the dev_loss_tmo fires, or when the rport is deleted
due to other circumstances (module unload, etc). It is expected that
the callback will initiate the termination of any outstanding i/o on
the rport.
- fast_io_fail_tmo and LLD callback:
There are some cases where it may take a long while to truly determine
device loss, but the system is in a multipathing configuration that if
the i/o was failed quickly (faster than dev_loss_tmo), it could be
redirected to a different path and completed sooner.
Many thanks to Mike Reed who cleaned up the initial RFC in support
of this post.
The original RFC is at:
http://marc.theaimsgroup.com/?l=linux-scsi&m=115505981027246&w=2
Signed-off-by: James Smart <James.Smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
During discussions with Mike Christie, I became convinced that we needed
a larger vendor id. This patch extends the id from 32 to 64 bits.
This applies on top of the prior patches that add SCSI transport events
via netlink.
Signed-off-by: James Smart <James.Smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch formally adds support for the posting of FC events via netlink.
It is a followup to the original RFC at:
http://marc.theaimsgroup.com/?l=linux-scsi&m=114530667923464&w=2
and the initial posting at:
http://marc.theaimsgroup.com/?l=linux-scsi&m=115507374832500&w=2
The patch has been updated to optimize the send path, per the discussions
in the initial posting.
Per discussions at the Storage Summit and at OLS, we are to use netlink for
async events from transports. Also per discussions, to avoid a netlink
protocol per transport, I've create a single NETLINK_SCSITRANSPORT protocol,
which can then be used by all transports.
This patch:
- Creates new files scsi_netlink.c and scsi_netlink.h, which contains the
single and shared definitions for the SCSI Transport. It is tied into the
base SCSI subsystem intialization.
Contains a single interface routine, scsi_send_transport_event(), for a
transport to send an event (via multicast to a protocol specific group).
- Creates a new scsi_netlink_fc.h file, which contains the FC netlink event
messages
- Adds 3 new routines to the fc transport:
fc_get_event_number() - to get a FC event #
fc_host_post_event() - to send a simple FC event (32 bits of data)
fc_host_post_vendor_event() - to send a Vendor unique event, with
arbitrary amounts of data.
Note: the separation of event number allows for a LLD to send a standard
event, followed by vendor-specific data for the event.
Note: This patch assumes 2 prior fc transport patches have been installed:
http://marc.theaimsgroup.com/?l=linux-scsi&m=115555807316329&w=2http://marc.theaimsgroup.com/?l=linux-scsi&m=115581614930261&w=2
Sorry - next time I'll do something like making these individual
patches of the same posting when I know they'll be posted closely
together.
Signed-off-by: James Smart <James.Smart@emulex.com>
Tidy up configuration not to make SCSI always select NET
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch updates the fc transport for the following:
- Addition of a new attribute "system_hostname" which can be
used to set the fully qualified hostname that the fc_host
is attached to. The fc_host can then register this string
as the FDMI-based host name attribute.
Note: for NPIV, a fc_host could be associated with a system which
is not the local system.
- Add the inline function u64_to_wwn(), which is the inverse of the
existing wwn_to_u64() function.
- Slight reorg, just to keep dynamic attributes with each other, etc
Signed-off-by: James Smart <James.Smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Original post was incorrect as it didn't realize that we already had
a self-referenc due to device_initialize(), and we were really only
missing the put on our own reference. This was hidden by the other bug
which had the midlayer reusing stargets after they were already free,
which was doing too many puts on our rport.
Updating FC transport for:
- Add put in fc_rport_final_delete(), to release the rport.
Prior, we were leaving the rport with a reference, thus the shost
with references, etc. If the driver was unloaded, shosts and rports
remained, along with work threads, etc
- Fix fc_rport_create failure path - too many put's on parent
- Add commenting to easily track ref taking.
Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Updated patch to address comments from Pat Mansfield and Michael Reed:
Bumped max to 600 (10mins). Set default dev_loss_tmo to a value other
than the max (30s).
Signed-off-by: James Smart <James.Smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
In a prior posting to linux-scsi on the fc transport and workq
deadlocks, we noted a second error that did not have a patch:
http://marc.theaimsgroup.com/?l=linux-scsi&m=114467847711383&w=2
- There's a deadlock where scsi_remove_target() has to sit behind
scsi_scan_target() due to contention over the scan_lock().
Subsequently we posted a request for comments about the deadlock:
http://marc.theaimsgroup.com/?l=linux-scsi&m=114469358829500&w=2
This posting resolves the second error. Here's what we now understand,
and are implementing:
If the lldd deletes the rport while a scan is active, the sdev's queue
is blocked which stops the issuing of commands associated with the scan.
At this point, the scan stalls, and does so with the shost->scan_mutex held.
If, at this point, if any scan or delete request is made on the host, it
will stall waiting for the scan_mutex.
For the FC transport, we queue all delete work to a single workq.
So, things worked fine when competing with the scan, as long as the
target blocking the scan was the same target at the top of our delete
workq, as the delete workq routine always unblocked just prior to
requesting the delete. Unfortunately, if the top of our delete workq
was for a different target, we deadlock. Additionally, if the target
blocking scan returned, we were unblocking it in the scan workq routine,
which really won't execute until the existing stalled scan workq
completes (e.g. we're re-scheduling it while it is in the midst of its
execution).
This patch moves the unblock out of the workq routines and moves it to
the context that is scheduling the work. This ensures that at some point,
we will unblock the target that is blocking scan. Please note, however,
that the deadlock condition may still occur while it waits for the
transport to timeout an unblock on a target. Worst case, this is bounded
by the transport dev_loss_tmo (default: 30 seconds).
Finally, Michael Reed deserves the credit for the bulk of this patch,
analysis, and it's testing. Thank you for your help.
Note: The request for comments statements about the gross-ness of the
scan_mutex still stand.
Signed-off-by: Michael Reed <mdr@sgi.com>
Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove
duplicates of the macro.
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
As previously reported via Michael Reed, the FC transport took a hit
in 2.6.15 (perhaps a little earlier) when we solved a recursion error.
There are 2 deadlocks occurring:
- With scan and the delete items sharing the same workq, flushing the
workq for the delete code was getting it stalled behind a very long
running scan code path.
- There's a deadlock where scsi_remove_target() has to sit behind
scsi_scan_target() due to contention over the scan_lock().
This patch resolves the 1st deadlock and significantly reduces the
odds of the second. So far, we have only replicated the 2nd deadlock
on a highly-parallel SMP system. More on the 2nd deadlock in a following
email.
This patch reworks the transport to:
- Only use the scsi host workq for scanning
- Use 2 other workq's internally. One for deletions, the other for
scheduled deletions. Originally, we tried this with a single workq,
but the occassional flushes of the scheduled queues was hitting the
second deadlock with a slightly higher frequency. In the future, we'll
look at the LLDD's and the transport to see if we can get rid of this
extra overhead.
- When moving to the other workq's we tightened up some object states
and some lock handling.
- Properly syncs adds/deletes
- minor code cleanups
- directly reference fc_host_attrs, rather than through attribute
macros
- flush the right workq on delayed work cancel failures.
Large kudos to Michael Reed who has been working this issue for the last
month.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This moves the eh_timed_out functionality from the scsi_host_template
to the transport_template. Given that this is now a transport function,
the EH_RESET_TIMER case no longer caps the timer reschedulings. The
transport guarantees that this is not an infinite condition.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
In the past I added an host attribute but unfortunately
I forgot to increase FC_HOST_NUM_ATTRS.
This is fixed with the patch. Otherwise an fibre channel
lld might run into
BUG_ON(count > FC_HOST_NUM_ATTRS);
in fc_attach_transport().
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Change the core SCSI code to use kzalloc rather than kmalloc+memset
where possible.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Current fc_transport consumers initially register rports
with an UNKNOWN role-state and follow-up with a call to
fc_remote_port_rolechg(). Modify code in
fc_remote_port_add() to scan the fc_host_rport_bindings()
array for consistent bindings regardless of role-type.
Original code would only scan bindings array for targets,
causing duplicate fc_remote_ports/rport-X:Y-Z entries to be
created for the yet-to-be-role-changed rports.
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
When James Smart fixed the issue of the userspace scan atributes
crashing the system with the FC transport class he added a patch to
let the transport class check if the parent is valid for a given
transport class.
When adding support for the integrated raid of fusion sas devices
we ran into a problem with that, as it didn't allow adding virtual
raid volumes without the transport class knowing about it.
So this patch adds a user_scan attribute instead, that takes over from
scsi_scan_host_selected if the transport class sets it and thus lets
the transport class control the user-initiated scanning. As this
plugs the hole about user-initiated scanning the target_parent hook
goes away and we rely on callers of the scanning routines to do
something sensible.
For SAS this meant I had to switch from a spinlock to a mutex to
synchronize the topology linked lists, in FC they were completely
unsynchronized which seems wrong.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Add fc_host attribute permanent_port_name which is
used to show the port name of the primary port -
the port that initially logged into the fabric.
For a virtual port (registered via the primary port with
FDISC command) it is useful to know not only its (virtual)
port name but also the permanent port name.
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
In the scenario that a link was broken, the devloss timer for each
rport was expire at roughly the same time, causing lots of "delete"
workqueue items being queued. Depth is dependent upon the number of
rports that were on the link.
The rport target remove calls were calling flush_scheduled_work(),
which would interrupt the stream, and start the next workqueue item,
which did the same thing, and so on until recursion depth was large.
This fix stops the recursion in the initial delete path, and pushes it
off to a host-level work item that reaps the dead rports.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
patch below marks a few scsi core datastructures as const, so that they end up
in the .rodata section and don't cacheline share with things that get dirtied
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Uwe Kleine-König
Tim Schmielau
David Howells
James Bottomley
James Smart
Tobias Klauser
James Bottomley
Andreas Herrmann
Jes Sorensen
Andrew Vasquez
Christoph Hellwig
Linus Torvalds
Arjan van de Ven