kernel.git/drivers/scsi/hosts.c, branch linux-2.6.36.y

[SCSI] implement runtime Power Management

2010-07-28T14:07:50Z

This patch (as1398b) adds runtime PM support to the SCSI layer. Only the machanism is provided; use of it is up to the various high-level drivers, and the patch doesn't change any of them. Except for sg -- the patch expicitly prevents a device from being runtime-suspended while its sg device file is open. The implementation is simplistic. In general, hosts and targets are automatically suspended when all their children are asleep, but for them the runtime-suspend code doesn't actually do anything. (A host's runtime PM status is propagated up the device tree, though, so a runtime-PM-aware lower-level driver could power down the host adapter hardware at the appropriate times.) There are comments indicating where a transport class might be notified or some other hooks added. LUNs are runtime-suspended by calling the drivers' existing suspend handlers (and likewise for runtime-resume). Somewhat arbitrarily, the implementation delays for 100 ms before suspending an eligible LUN. This is because there typically are occasions during bootup when the same device file is opened and closed several times in quick succession. The way this all works is that the SCSI core increments a device's PM-usage count when it is registered. If a high-level driver does nothing then the device will not be eligible for runtime-suspend because of the elevated usage count. If a high-level driver wants to use runtime PM then it can call scsi_autopm_put_device() in its probe routine to decrement the usage count and scsi_autopm_get_device() in its remove routine to restore the original count. Hosts, targets, and LUNs are not suspended while they are being probed or removed, or while the error handler is running. In fact, a fairly large part of the patch consists of code to make sure that things aren't suspended at such times. [jejb: fix up compile issues in PM config variations] Signed-off-by: Alan Stern Signed-off-by: James Bottomley

[SCSI] scsi:hosts.c Fix warning: variable 'rval' set but not used

2010-07-27T17:03:51Z

The below patch fixes a warning message generated by gcc 4.6.0 CC drivers/scsi/hosts.o drivers/scsi/hosts.c: In function 'scsi_host_alloc': drivers/scsi/hosts.c:328:6: warning: variable 'rval' set but not used Fix this by removing the rval but placing a printk warning where it would have been set. Signed-off-by: Justin P. Mattock Signed-off-by: James Bottomley

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32Z

percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn

PM: Allow SCSI devices to suspend/resume asynchronously

2010-02-26T19:39:12Z

Set power.async_suspend for all SCSI devices, targets and hosts, so that they can be suspended and resumed in parallel with the main suspend/resume thread and possibly with other devices they don't depend on in a known way (i.e. devices which are not their parents or children). The power.async_suspend flag is also set for devices that don't have suspend or resume callbacks, because otherwise they would make the main suspend/resume thread wait for their "asynchronous" children (during suspend) or parents (during resume), effectively negating the possible gains from executing these devices' suspend and resume callbacks asynchronously. Signed-off-by: Rafael J. Wysocki

Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6

2009-12-10T03:42:25Z

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (222 commits) [SCSI] zfcp: Remove flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP [SCSI] zfcp: Activate fc4s attributes for zfcp in FC transport class [SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED [SCSI] zfcp: Update FSF error reporting [SCSI] zfcp: Improve ELS ADISC handling [SCSI] zfcp: Simplify handling of ct and els requests [SCSI] zfcp: Remove ZFCP_DID_MASK [SCSI] zfcp: Move WKA port to zfcp FC code [SCSI] zfcp: Use common code definitions for FC CT structs [SCSI] zfcp: Use common code definitions for FC ELS structs [SCSI] zfcp: Update FCP protocol related code [SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport [SCSI] zfcp: Assign scheduled work to driver queue [SCSI] zfcp: Remove STATUS_COMMON_REMOVE flag as it is not required anymore [SCSI] zfcp: Implement module unloading [SCSI] zfcp: Merge trace code for fsf requests in one function [SCSI] zfcp: Access ports and units with container_of in sysfs code [SCSI] zfcp: Remove suspend callback [SCSI] zfcp: Remove global config_mutex [SCSI] zfcp: Replace local reference counting with common kref ...

[SCSI] scsi_lib_dma: fix bug with dma maps on nested scsi objects

2009-12-04T18:01:30Z

Some of our virtual SCSI hosts don't have a proper bus parent at the top, which can be a problem for doing DMA on them This patch makes the host device cache a pointer to the physical bus device and provides an extra API for setting it (the normal API picks it up from the parent). This patch also modifies the qla2xxx and lpfc vport logic to use the new DMA host setting API. Acked-By: James Smart Cc: Stable Tree Signed-off-by: James Bottomley

[SCSI] fix crash when disconnecting usb storage

2009-11-26T16:04:22Z

__scsi_remove_device() in scsi_forget_host() is executed out of scan_mutex and races with scsi_destroy_sdev() <- scsi_sysfs_add_devices() <- scsi_finish_async_scan(). The result is use after free and/or double free, oops. The fix is simple, move scsi_forget_host() under scan_mutex. scsi_forget_host() is just sequence of __scsi_remove_device(). All another calls of __scsi_remove_device() are made under scan_mutex. So that it is safe. Signed-off-by: Alexey Kuznetsov Signed-off-by: Denis V. Lunev Signed-off-by: Andrew Morton Signed-off-by: James Bottomley

fix race that can give duplicate host number

2009-06-21T15:52:42Z

Just once, two fcoe instances got the same host number from scsi_add_host(). Use atomic_t and atomic_inc_return() to get next host number. Subtract 1, so that scsi_host still starts with 0. [jejb: added comment about unusual subtraction] Signed-off-by: Joe Eykholt Signed-off-by: James Bottomley

[SCSI] fix /proc memory leak in the SCSI core

2009-03-12T17:58:17Z

The SCSI core calls scsi_proc_hostdir_add() from within scsi_host_alloc(), but the corresponding scsi_proc_hostdir_rm() routine is called from within scsi_remove_host(). As a result, if a host is allocated and then deallocated without ever being registered, the host's directory in /proc is leaked. This patch (as1181b) fixes this bug in the SCSI core by moving scsi_proc_hostdir_rm() into scsi_host_dev_release(). Signed-off-by: Alan Stern Signed-off-by: James Bottomley

[SCSI] struct device - replace bus_id with dev_name(), dev_set_name()

2009-01-02T16:22:16Z

[jejb: limit ioctl to returning 20 characters to avoid overrun on long device names and add a few more conversions] Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman Signed-off-by: James Bottomley