linux/include
Dan Williams b1124cd3ec [SCSI] libsas: introduce sas_drain_work()
When an lldd invokes ->notify_port_event() it can trigger a chain of libsas
events to:

  1/ form the port and find the direct attached device

  2/ if the attached device is an expander perform domain discovery

A call to flush_workqueue() will only flush the initial port formation work.
Currently libsas users need to call scsi_flush_work() up to the max depth of
chain (which will grow from 2 to 3 when ata discovery is moved to its own
discovery event).  Instead of open coding multiple calls switch to use
drain_workqueue() to flush sas work.

drain_workqueue() does not handle new work submitted during the drain so
libsas needs a bit of infrastructure to hold off unchained work submissions
while a drain is in flight.  A lldd ->notify() event is considered 'unchained'
while a sas_discover_event() is 'chained'.  As Tejun notes:

  "For now, I think it would be best to add private wrapper in libsas to
   support deferring unchained work items while draining."

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-19 13:48:51 -06:00
..
acpi Merge branches 'atomicio-apei', 'hotplug', 'sony-nvs-nosave' and 'thermal-netlink' into release 2012-01-23 19:47:06 -05:00
asm-generic lib: add NO_GENERIC_PCI_IOPORT_MAP 2012-01-31 23:19:47 +02:00
crypto
drm drm: Fix authentication kernel crash 2012-01-25 09:27:45 +00:00
keys keys: add a "logon" key type 2012-01-17 22:39:40 -06:00
linux [SCSI] virtio-scsi: SCSI driver for QEMU based virtual machines 2012-02-19 09:50:20 -06:00
math-emu
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-01-18 12:53:54 -08:00
misc
mtd mtd: document that MEMWRITE ioctl is NAND-specific 2012-01-09 18:18:36 +00:00
net netprio_cgroup: fix wrong memory access when NETPRIO_CGROUP=m 2012-02-10 15:08:57 -05:00
pcmcia
rdma rdma/core: Fix sparse warnings 2012-01-04 09:17:45 -08:00
rxrpc
scsi [SCSI] libsas: introduce sas_drain_work() 2012-02-19 13:48:51 -06:00
sound Merge branch 'fix/asoc' into for-linus 2012-01-31 15:13:14 +01:00
target target: Change target_submit_cmd() to return void 2012-02-07 06:41:04 +00:00
trace writeback: fix dereferencing NULL bdi->dev on trace_writeback_queue 2012-02-06 11:17:25 +08:00
video fbdev fixes for 3.3 2012-02-07 15:54:02 -08:00
xen Merge branch 'for-3.3/drivers' of git://git.kernel.dk/linux-block 2012-01-15 12:48:41 -08:00
Kbuild