26 Jul, 2012
1 commit
-
Two bits were appended to the end of the bitfield
list in struct scsi_device. Resolve that conflict
by including both bits.Conflicts:
include/scsi/scsi_device.h
20 Jul, 2012
1 commit
-
During alua transitions, an array can return transitioning
status in response to rtpg requests. These requests get
retried for a maximum of 60 seconds by default before timing
out. Sometimes this timeout isn't sufficient to allow the
array to complete the transition. T10-spc4 addresses this
under 'Report Target Port Groups' command.This update retrieves the timeout value from the storage
array if available and retries the transitioning rtpgs
for up to the 'implied transitioning timeout' valueSigned-off-by: Rob Evers
Reviewed-by: Babu Moger
Signed-off-by: James Bottomley
29 Jun, 2012
1 commit
-
For being able to bind ata devices against acpi devices, scsi_bus_type
needs to be set as bus in struct acpi_bus_type. So add wrapper to
scsi_lib to accomplish that.Signed-off-by: Holger Macht
Signed-off-by: Lin Ming
Signed-off-by: Jeff Garzik
26 Feb, 2012
1 commit
-
It's in SBC-3.
Signed-off-by: Andy Grover
Cc: Christoph Hellwig
Cc: James Bottomley
Signed-off-by: Nicholas Bellinger
21 Jul, 2011
1 commit
-
All these are instances of
#define NAME value;
or
#define NAME(params_opt) value;These of course fail to build when used in contexts like
if(foo $OP NAME)
while(bar $OP NAME)
and may silently generate the wrong code in contexts such as
foo = NAME + 1; /* foo = value; + 1; */
bar = NAME - 1; /* bar = value; - 1; */
baz = NAME & quux; /* baz = value; & quux; */Reported on comp.lang.c,
Message-ID:
Initial analysis of the dangers provided by Keith Thompson in that thread.There are many more instances of more complicated macros having unnecessary
trailing semicolons, but this pile seems to be all of the cases of simple
values suffering from the problem. (Thus things that are likely to be found
in one of the contexts above, more complicated ones aren't.)Signed-off-by: Phil Carmody
Signed-off-by: Jiri Kosina
18 Mar, 2011
1 commit
-
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (170 commits)
[SCSI] scsi_dh_rdac: Add MD36xxf into device list
[SCSI] scsi_debug: add consecutive medium errors
[SCSI] libsas: fix ata list corruption issue
[SCSI] hpsa: export resettable host attribute
[SCSI] hpsa: move device attributes to avoid forward declarations
[SCSI] scsi_debug: Logical Block Provisioning (SBC3r26)
[SCSI] sd: Logical Block Provisioning update
[SCSI] Include protection operation in SCSI command trace
[SCSI] hpsa: fix incorrect PCI IDs and add two new ones (2nd try)
[SCSI] target: Fix volume size misreporting for volumes > 2TB
[SCSI] bnx2fc: Broadcom FCoE offload driver
[SCSI] fcoe: fix broken fcoe interface reset
[SCSI] fcoe: precedence bug in fcoe_filter_frames()
[SCSI] libfcoe: Remove stale fcoe-netdev entries
[SCSI] libfcoe: Move FCOE_MTU definition from fcoe.h to libfcoe.h
[SCSI] libfc: introduce __fc_fill_fc_hdr that accepts fc_hdr as an argument
[SCSI] fcoe, libfc: initialize EM anchors list and then update npiv EMs
[SCSI] Revert "[SCSI] libfc: fix exchange being deleted when the abort itself is timed out"
[SCSI] libfc: Fixing a memory leak when destroying an interface
[SCSI] megaraid_sas: Version and Changelog update
...Fix up trivial conflicts due to whitespace differences in
drivers/scsi/libsas/{sas_ata.c,sas_scsi_host.c}
13 Feb, 2011
1 commit
-
Instead of just passing 'EIO' for any I/O error we should be
notifying the upper layers with more details about the cause
of this error.Update the possible I/O errors to:
- ENOLINK: Link failure between host and target
- EIO: Retryable I/O error
- EREMOTEIO: Non-retryable I/O error
- EBADE: I/O error restricted to the I_T_L nexus'Retryable' in this context means that an I/O error _might_ be
restricted to the I_T_L nexus (vulgo: path), so retrying on another
nexus / path might succeed.'Non-retryable' in general refers to a target failure, so this
error will always be generated regardless of the I_T_L nexus
it was send on.I/O errors restricted to the I_T_L nexus might be retried
on another nexus / path, but they should _not_ be queued
if no paths are available.Signed-off-by: Hannes Reinecke
Signed-off-by: Mike Snitzer
Signed-off-by: James Bottomley
25 Jan, 2011
1 commit
-
If the compiled object doesn't include linux/scatterlist.h before
scsi/scsi.h, it will get an incorrect definition of
SCSI_MAX_SG_CHAIN_SEGMENTS.Signed-off-by: David Dillow
Cc: stable@kernel.org
Signed-off-by: James Bottomley
14 Jan, 2011
1 commit
-
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
block: ensure that completion error gets properly traced
blktrace: add missing probe argument to block_bio_complete
block cfq: don't use atomic_t for cfq_group
block cfq: don't use atomic_t for cfq_queue
block: trace event block fix unassigned field
block: add internal hd part table references
block: fix accounting bug on cross partition merges
kref: add kref_test_and_get
bio-integrity: mark kintegrityd_wq highpri and CPU intensive
block: make kblockd_workqueue smarter
Revert "sd: implement sd_check_events()"
block: Clean up exit_io_context() source code.
Fix compile warnings due to missing removal of a 'ret' variable
fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
cfq-iosched: don't check cfqg in choose_service_tree()
fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
cdrom: export cdrom_check_events()
sd: implement sd_check_events()
sr: implement sr_check_events()
...
22 Dec, 2010
1 commit
-
This patch adds a handful of missing CDBs defs that are used by TCM
persistent reservation logic in the SPC-4 defined CDB exclusion table for
registrations and reservations.This includes a number of missing MI_* and MO_* prefixed service actions defs
for MAINTENANCE_IN and MAINTENANCE_OUT that are mentioned wrt to persistent
registration and reservation status for the SCSI Initiator Port.Signed-off-by: Nicholas A. Bellinger
Signed-off-by: James Bottomley
17 Dec, 2010
1 commit
-
Replace sr_media_change() with sr_check_events(). It normally only
uses GET_EVENT_STATUS_NOTIFICATION to check both media change and
eject request. If @clearing includes DISK_EVENT_MEDIA_CHANGE, it
issues TUR and compares whether media presence has changed. The SCSI
specific media change uevent is kept for compatibility.sr_media_change() was doing both media change check and revalidation.
The revalidation part is split into sr_block_revalidate_disk().Signed-off-by: Tejun Heo
Cc: Kay Sievers
Signed-off-by: Jens Axboe
23 Oct, 2010
2 commits
-
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (141 commits)
USB: mct_u232: fix broken close
USB: gadget: amd5536udc.c: fix error path
USB: imx21-hcd - fix off by one resource size calculation
usb: gadget: fix Kconfig warning
usb: r8a66597-udc: Add processing when USB was removed.
mxc_udc: add workaround for ENGcm09152 for i.MX35
USB: ftdi_sio: add device ids for ScienceScope
USB: musb: AM35x: Workaround for fifo read issue
USB: musb: add musb support for AM35x
USB: AM35x: Add musb support
usb: Fix linker errors with CONFIG_PM=n
USB: ohci-sh - use resource_size instead of defining its own resource_len macro
USB: isp1362-hcd - use resource_size instead of defining its own resource_len macro
USB: isp116x-hcd - use resource_size instead of defining its own resource_len macro
USB: xhci: Fix compile error when CONFIG_PM=n
USB: accept some invalid ep0-maxpacket values
USB: xHCI: PCI power management implementation
USB: xHCI: bus power management implementation
USB: xHCI: port remote wakeup implementation
USB: xHCI: port power management implementation
...Manually fix up (non-data) conflict: the SCSI merge gad renamed the
'hw_sector_size' member to 'physical_block_size', and the USB tree
brought a new use of it. -
This commit changes storage_common.h, file_storage.c and
f_mass_storage.c to use definitions of SCSI commands from
scsi/scsi.h file instead of redefining the commands in
storage_common.c.scsi/scsi.h header file was missing READ_FORMAT_CAPACITIES and
READ_HEADER so this commit also add those to the header.Signed-off-by: Michal Nazarewicz
Cc: Alan Stern
Cc: James Bottomley
Signed-off-by: Greg Kroah-Hartman
11 Sep, 2010
1 commit
-
Some controllers have a hardware limit on the number of protection
information scatter-gather list segments they can handle.Introduce a max_integrity_segments limit in the block layer and provide
a new scsi_host_template setting that allows HBA drivers to provide a
value suitable for the hardware.Add support for honoring the integrity segment limit when merging both
bios and requests.Signed-off-by: Martin K. Petersen
Signed-off-by: Jens Axboe
11 Aug, 2010
1 commit
-
Commit 9e4f5e29 ("FC Pass Thru support") exported a number of header files
in include/scsi to user space, but didn't change the uX types to the
userspace-compatible __uX types. Without that you'll get compile errors
when including them - E.G.:include/scsi/scsi.h:145: error: expected specifier-qualifier-list before `u8'
Signed-off-by: Peter Korsgaard
Cc: Boaz Harrosh
Cc: James Smart
Cc: James Bottomley
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 May, 2010
1 commit
-
Add definitions for VERIFY(12) and VERIFY(32).
Signed-off-by: Martin K. Petersen
Signed-off-by: James Bottomley
11 Apr, 2010
1 commit
-
If the scsi eh is running and then a FC LLD calls
fc_remote_port_delete, the SCSI commands sent from the eh will fail.
To prevent this, a FC LLD can call fc_block_scsi_eh from the eh
callback, blocking the eh thread until the dev_loss_tmo fires or the
remote port is available again.If (e.g. for a multipathing setup) the dev_loss_tmo is set to a very
large value, thus preventing the scsi device removal , the scsi eh can
block for a long time. For multipathing, the fast_io_fail_tmo is then
set to a low value to detect path problems sooner.This patch introduces a new return code FAST_IO_FAIL. The function
fc_block_scsi_eh now returns FAST_IO_FAIL when the fast_io_fail_tmo
fires. This indicates that the LLD terminated all pending I/O requests
and there are no more pending SCSI commands for the scsi eh to wait
for. This return code can be passed back to the scsi eh to stop the
escalation and finish the recovery process for this device.Signed-off-by: Christof Schmitt
Signed-off-by: James Bottomley
05 Dec, 2009
1 commit
-
Add definitions for UNMAP, WRITE SAME{16,32} and GET LBA STATUS
commands.Signed-off-by: Martin K. Petersen
Signed-off-by: James Bottomley
02 Oct, 2009
1 commit
-
Disks formatted with DIF Type 2 reject READ/WRITE 6/10/12/16 commands
when protection is enabled. Only the 32-byte variants are supported.Implement support for issusing 32-byte READ/WRITE and enable Type 2
drives in the protection type detection logic.Signed-off-by: Martin K. Petersen
Signed-off-by: James Bottomley
13 Mar, 2009
3 commits
-
This allows it to compile and be used on the ps3 platform that wants
to use the #define values in scsi.h without actually having
CONFIG_SCSI set.Signed-off-by: James Bottomley
-
- Define the OSD_TYPE scsi device and let it show up in scans
Signed-off-by: Boaz Harrosh
Signed-off-by: James Bottomley -
The SUGGEST_* flags in the SCSI command result have been out of fashion
for a while and we don't actually use them in the error handling.
Remove the remaining occurrences.Signed-off-by: Martin K. Petersen
Signed-off-by: James Bottomley
13 Oct, 2008
2 commits
-
Currently, if there is a transport problem the iscsi drivers will return
outstanding commands (commands being exeucted by the driver/fw/hw) with
DID_BUS_BUSY and block the session so no new commands can be queued.
Commands that are caught between the failure handling and blocking are
failed with DID_IMM_RETRY or one of the scsi ml queuecommand return values.
When the recovery_timeout fires, the iscsi drivers then fail IO with
DID_NO_CONNECT.For fcp, some drivers will fail some outstanding IO (disk but possibly not
tape) with DID_BUS_BUSY or DID_ERROR or some other value that causes a retry
and hits the scsi_error.c failfast check, block the rport, and commands
caught in the race are failed with DID_IMM_RETRY. Other drivers, may
hold onto all IO and wait for the terminate_rport_io or dev_loss_tmo_callbk
to be called.The following patches attempt to unify what upper layers will see drivers
like multipath can make a good guess. This relies on drivers being
hooked into their transport class.This first patch just defines two new host byte errors so drivers can
return the same value for when a rport/session is blocked and for
when the fast_io_fail_tmo fires.The idea is that if the LLD/class detects a problem and is going to block
a rport/session, then if the LLD wants or must return the command to scsi-ml,
then it can return it with DID_TRANSPORT_DISRUPTED. This will requeue
the IO into the same scsi queue it came from, until the fast io fail timer
fires and the class decides what to do.When using multipath and the fast_io_fail_tmo fires then the class
can fail commands with DID_TRANSPORT_FAILFAST or drivers can use
DID_TRANSPORT_FAILFAST in their terminate_rport_io callbacks or
the equivlent in iscsi if we ever implement more advanced recovery methods.
A LLD, like lpfc, could continue to return DID_ERROR and then it will hit
the normal failfast path, so drivers do not have fully be ported to
work better. The point of the patches is that upper layers will
not see a failure that could be recovered from while the rport/session is
blocked until fast_io_fail_tmo/recovery_timeout fires.V3
Remove some comments.
V2
Fixed patch/diff errors and renamed DID_TRANSPORT_BLOCKED to
DID_TRANSPORT_DISRUPTED.
V1
initial patch.Signed-off-by: Mike Christie
Signed-off-by: James Bottomley -
SCSI-ml manages the queueing limits for the device and host, but
does not do so at the target level. However something something similar
can come in userful when a driver is transitioning a transport object to
the the blocked state, becuase at that time we do not want to queue
io and we do not want the queuecommand to be called again.The patch adds code similar to the exisiting SCSI_ML_*BUSY handlers.
You can now return SCSI_MLQUEUE_TARGET_BUSY when we hit
a transport level queueing issue like the hw cannot allocate some
resource at the iscsi session/connection level, or the target has temporarily
closed or shrunk the queueing window, or if we are transitioning
to the blocked state.bnx2i, when they rework their firmware according to netdev
developers requests, will also need to be able to limit queueing at this
level. bnx2i will hook into libiscsi, but will allocate a scsi host per
netdevice/hba, so unlike pure software iscsi/iser which is allocating
a host per session, it cannot set the scsi_host->can_queue and return
SCSI_MLQUEUE_HOST_BUSY to reflect queueing limits on the transport.The iscsi class/driver can also set a scsi_target->can_queue value which
reflects the max commands the driver/class can support. For iscsi this
reflects the number of commands we can support for each session due to
session/connection hw limits, driver limits, and to also reflect the
session/targets's queueing window.Changes:
v1 - initial patch.
v2 - Fix scsi_run_queue handling of multiple blocked targets.
Previously we would break from the main loop if a device was added back on
the starved list. We now run over the list and check if any target is
blocked.
v3 - Rediff for scsi-misc.Signed-off-by: Mike Christie
Signed-off-by: James Bottomley
29 Aug, 2008
1 commit
-
For IBM z series certain LUNs can no longer be accessed.
This is because kernel version 2.6.19 a check was introduced not to
create a generic SCSI device for devices that return PQ=1 and
PDT=0x1f. For WLUNs (see SAM-3, p. 41ff) generic SCSI devices should
be created unconditionally without looking at the PQ bit, so add a
check for WLUNs in with this test.Acked-by: Martin Petermann
Signed-off-by: James Bottomley
27 Jul, 2008
1 commit
-
Signed-off-by: Hannes Reinecke
Signed-off-by: Chandra Seetharaman
Signed-off-by: James Bottomley
12 Jul, 2008
1 commit
-
Move the accessor functions for the scsi_cmnd status from zfcp to the
SCSI include file. Change the interface to the functions to pass the
scsi_cmnd pointer instead of the status pointer.Signed-off-by: Martin Petermann
Signed-off-by: Christof Schmitt
Signed-off-by: James Bottomley
05 Jun, 2008
1 commit
-
Some of the storage devices (that can be accessed through multiple paths),
do need some special handling for
1. Activating the passive path of the storage access.
2. Decode and handle the special sense codes returned by the devices.
3. Handle the I/Os being sent to the passive path, especially
during the device probe time.
when accessed through multiple paths.As of today this special device handling is done at the dm-multipath
layer using dm-handlers. That works well for (1); for (2) to be handled
at dm layer, scsi sense information need to be exported from SCSI to dm-layer,
which is not very attractive; (3) cannot be done at all at the dm layer.Device handler has been moved to SCSI mainly to handle (2) and (3) properly.
Signed-off-by: Chandra Seetharaman
Signed-off-by: Mike Anderson
Signed-off-by: Mike Christie
Signed-off-by: James Bottomley
03 May, 2008
1 commit
-
Add support for variable-length, extended, and vendor specific
CDBs to scsi-ml. It is now possible for initiators and ULD's
to issue these types of commands. LLDs need not change much.
All they need is to raise the .max_cmd_len to the longest command
they support (see iscsi patch).- clean-up some code paths that did not expect commands to be
larger than 16, and change cmd_len members' type to short as
char is not enough.Signed-off-by: Boaz Harrosh
Signed-off-by: Benny Halevy
Signed-off-by: James Bottomley
08 Feb, 2008
1 commit
-
A lot of SCSI command replies have a protocol ID field. Add
definitions for the interpretation of that from SPC-3.Signed-off-by: James Bottomley
31 Jan, 2008
2 commits
-
Signed-off-by: FUJITA Tomonori
Acked-by: Douglas Gilbert
Signed-off-by: James Bottomley -
With the sg table code, every SCSI driver is now either chain capable
or broken (or has sg_tablesize set so chaining is never activated), so
there's no need to have a check in the host template.Also tidy up the code by moving the scatterlist size defines into the
SCSI includes and permit the last entry of the scatterlist pools not
to be a power of two.
Signed-off-by: James Bottomley
16 Oct, 2007
1 commit
-
This is what enables large commands. If we need to allocate an
sgtable that doesn't fit in a single page, allocate several
SCSI_MAX_SG_SEGMENTS sized tables and chain them together.SCSI defaults to large chained sg tables, if the arch supports it.
Signed-off-by: Jens Axboe
18 Apr, 2007
1 commit
-
The following patch adds support for sysfs/uevent modalias
attribute for scsi devices (like disks, tapes, cdroms etc),
based on whatever current sd.c, sr.c, st.c and osst.c drivers
supports.The modalias format is like this:
scsi:type-0x04
(for TYPE_WORM, handled by sr.c now).
Several comments.
o This hexadecimal type value is because all TYPE_XXX constants
in include/scsi/scsi.h are given in hex, but __stringify() will
not convert them to decimal (so it will NOT be scsi:type-4).
Since it does not really matter in which format it is, while
both modalias in module and modalias attribute match each other,
I descided to go for that 0x%02x format (and added a comment in
include/scsi/scsi.h to keep them that way), instead of changing
them all to decimal.o There was no .uevent routine for SCSI bus. It might be a good
idea to add some more ueven environment variables in there.o osst.c driver handles tapes too, like st.c, but only SOME tapes.
With this setup, hotplug scripts (or whatever is used by the
user) will try to load both st and osst modules for all SCSI
tapes found, because both modules have scsi:type-0x01 alias).
It is not harmful, but one extra module is no good either.
It is possible to solve this, by exporting more info in
modalias attribute, including vendor and device identification
strings, so that modalias becomes something like
scsi:type-0x12:vendor-Adaptec LTD:device-OnStream Tape Drive
and having that, match for all 3 attributes, not only device
type. But oh well, vendor and device strings may be large,
and they do contain spaces and whatnot.
So I left them for now, awaiting for comments first.Signed-off-by: Michael Tokarev
Signed-off-by: James Bottomley
26 Oct, 2006
2 commits
-
Signed-off-by: FUJITA Tomonori
Signed-off-by: Mike Christie
Signed-off-by: James Bottomley -
This patch adds support for REPORT TARGET PORT GROUPS. This is used
eg for the multipathing priority callout to determine the path
priority.
With this patch multipath-tools can use the existing mpath_prio_alua
callout to exercise the path priority grouping.Signed-off-by: Hannes Reinecke
Signed-off-by: Douglas Gilbert
Signed-off-by: James Bottomley
29 Aug, 2006
1 commit
-
This is the end point of the separate aic94xx driver based on the
original driver and transport class from Luben TuikovThe log of the separate development is:
Alexis Bruemmer:
o aic94xx: fix hotplug/unplug for expanderless systems
o aic94xx: disable split completion timer/setting by default
o aic94xx: wide port off expander support
o aic94xx: remove various inline functions
o aic94xx: use bitops
o aic94xx: remove queue comment
o aic94xx: remove sas_common.c
o aic94xx: sas remove depot's
o aic94xx: use available list_for_each_entry_safe_reverse()
o aic94xx: sas header file mergeJames Bottomley:
o aic94xx: fix TF_TMF_NO_CTX processing
o aic94xx: convert to request_firmware interface
o aic94xx: fix hotplug/unplug
o aic94xx: add link error counts to the expander phys
o aic94xx: add transport class phy reset capability
o aic94xx: remove local_attached flag
o Remove README
o Fixup Makefile variable for libsas rename
o Rename sas->libsas
o aic94xx: correct return code for sas_discover_event
o aic94xx: use parent backlink port
o aic94xx: remove channel abstraction
o aic94xx: fix routing algorithms
o aic94xx: add backlink port
o aic94xx: fix cascaded expander properties
o aic94xx: fix sleep under lock
o aic94xx: fix panic on module removal in complex topology
o aic94xx: make use of the new sas_port
o rename sas_port to asd_sas_port
o Fix for eh_strategy_handler move
o aic94xx: move entirely over to correct transport class formulation
o remove last vestages of sas_rphy_alloc()
o update for eh_timed_out move
o Preliminary expander support for aic94xx
o sas: remove event thread
o minor warning cleanups
o remove last vestiges of id mapping arrays
o Further updates
o Convert aic94xx over entirely to the transport class end device and
o update aic94xx/sas to use the new sas transport class end device
o [PATCH] aic94xx: attaching to the sas transport class
o Add missing completion removal from prior patch
o [PATCH] aic94xx: attaching to the sas transport class
o Build fixes from akpmJeff Garzik:
o [scsi aic94xx] Remove ->owner from PCI info tableLuben Tuikov:
o initial aic94xx driverMike Anderson:
o aic94xx: fix panic on module insertion
o aic94xx: stub out SATA_DEV case
o aic94xx: compile warning cleanups
o aic94xx: sas_alloc_task
o aic94xx: ref count update
o aic94xx nexus loss time value
o [PATCH] aic94xx: driver assertion in non-x86 BIOS envRandy Dunlap:
o libsas: externs not neededRobert Tarte:
o aic94xx: sequence patch - fixes SATA supportSigned-off-by: James Bottomley
07 Aug, 2006
1 commit
-
- Replace scsi_device_types array API with scsi_device_type function API.
Gets rid of a lot of common code, as well as being easier to use.
- Add the new device types in SPC4 r05a, and rename some of the older ones.
- Reformat the printing of inquiry data; now fits on one line and
includes PQ.I think I've addressed all the feedback from the previous versions. My
current test box prints:scsi 2:0:1:0: Direct access HP 18.2G ATLAS10K3_18_SCA HP05 PQ: 0 ANSI: 2
Signed-off-by: Matthew Wilcox
Signed-off-by: James Bottomley
28 Feb, 2006
1 commit
-
In order to use the new execute_in_process_context() API, you have to
provide it with the work storage, which I do in SCSI in scsi_device and
scsi_target, but which also means that we can no longer queue up the
target reaps, so instead I moved the target to a state model which
allows target_alloc to detect if we've received a dying target and wait
for it to be gone. Hopefully, this should also solve the target
namespace race.Signed-off-by: James Bottomley
15 Feb, 2006
1 commit
-
We have several points in the SCSI stack (primarily for our device
functions) where we need to guarantee process context, but (given the
place where the last reference was released) we cannot guarantee this.This API gets around the issue by executing the function directly if
the caller has process context, but scheduling a workqueue to execute
in process context if the caller doesn't have it. Unfortunately, it
requires memory allocation in interrupt context, but it's better than
what we have previously. The true solution will require a bit of
re-engineering, so isn't appropriate for 2.6.16.Signed-off-by: James Bottomley