kernel.git/drivers/scsi/scsi.c, branch linux-3.6.y

[SCSI] async: make async_synchronize_full() flush all work regardless of domain

2012-07-20T08:07:37Z

In response to an async related regression James noted: "My theory is that this is an init problem: The assumption in a lot of our code is that async_synchronize_full() waits for everything ... even the domain specific async schedules, which isn't true." ...so make this assumption true. Each domain, including the default one, registers itself on a global domain list when work is scheduled. Once all entries complete it exits that list. Waiting for the list to be empty syncs all in-flight work across all domains. Domains can opt-out of global syncing if they are declared as exclusive ASYNC_DOMAIN_EXCLUSIVE(). All stack-based domains have been declared exclusive since the domain may go out of scope as soon as the last work item completes. Statically declared domains are mostly ok, but async_unregister_domain() is there to close any theoretical races with pending async_synchronize_full waiters at module removal time. Signed-off-by: Dan Williams Acked-by: Arjan van de Ven Reported-by: Meelis Roos Reported-by: Eldad Zack Tested-by: Eldad Zack Signed-off-by: James Bottomley

[SCSI] async: introduce 'async_domain' type

2012-07-20T08:05:54Z

This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams Acked-by: Arjan van de Ven Acked-by: Mark Brown Tested-by: Eldad Zack Signed-off-by: James Bottomley

[SCSI] Fix sd_probe_domain config problem

2012-06-07T01:16:20Z

With CONFIG_BLK_DEV_SD = n and CONFIG_PM = n, you get this compile failure: (.text+0x4f6c77): undefined reference to `scsi_sd_probe_domain' This was introduced by commit a7a20d103994fd760766e6c9d494daa569cbfe06 Author: Dan Williams Date: Thu Mar 22 17:05:11 2012 -0700 [SCSI] sd: limit the scope of the async probe domain And happens because scsi_sd_probe_domain is conditionally defined but unconditionally used. Fix this by making the symbol unconditionally defined. Reported-by: Randy Dunlap Cc: Dan Williams Tested-by: Randy Dunlap Signed-off-by: James Bottomley

[SCSI] sd: limit the scope of the async probe domain

2012-05-17T08:10:46Z

sd injects and synchronizes probe work on the global kernel-wide domain. This runs into conflict with PM that wants to perform resume actions in async context: [ 494.237079] INFO: task kworker/u:3:554 blocked for more than 120 seconds. [ 494.294396] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 494.360809] kworker/u:3 D 0000000000000000 0 554 2 0x00000000 [ 494.420739] ffff88012e4d3af0 0000000000000046 ffff88013200c160 ffff88012e4d3fd8 [ 494.484392] ffff88012e4d3fd8 0000000000012500 ffff8801394ea0b0 ffff88013200c160 [ 494.548038] ffff88012e4d3ae0 00000000000001e3 ffffffff81a249e0 ffff8801321c5398 [ 494.611685] Call Trace: [ 494.632649] [] schedule+0x5a/0x5c [ 494.674687] [] async_synchronize_cookie_domain+0xb6/0x112 [ 494.734177] [] ? __init_waitqueue_head+0x50/0x50 [ 494.787134] [] ? scsi_remove_target+0x48/0x48 [ 494.837900] [] async_synchronize_cookie+0x15/0x17 [ 494.891567] [] async_synchronize_full+0x54/0x70 <-- here we wait for async contexts to complete [ 494.943783] [] ? async_synchronize_full_domain+0x1a/0x1a [ 495.002547] [] sd_remove+0x2c/0xa2 [sd_mod] [ 495.051861] [] __device_release_driver+0x86/0xcf [ 495.104807] [] device_release_driver+0x25/0x32 <-- here we take device_lock() [ 853.511341] INFO: task kworker/u:4:549 blocked for more than 120 seconds. [ 853.568693] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 853.635119] kworker/u:4 D ffff88013097b5d0 0 549 2 0x00000000 [ 853.695129] ffff880132773c40 0000000000000046 ffff880130790000 ffff880132773fd8 [ 853.758990] ffff880132773fd8 0000000000012500 ffff88013288a0b0 ffff880130790000 [ 853.822796] 0000000000000246 0000000000000040 ffff88013097b5c8 ffff880130790000 [ 853.886633] Call Trace: [ 853.907631] [] schedule+0x5a/0x5c [ 853.949670] [] __mutex_lock_common+0x220/0x351 [ 854.001225] [] ? device_resume+0x58/0x1c4 [ 854.049082] [] ? device_resume+0x58/0x1c4 [ 854.097011] [] mutex_lock_nested+0x2f/0x36 <-- here we wait for device_lock() [ 854.145591] [] device_resume+0x58/0x1c4 [ 854.192066] [] async_resume+0x1e/0x45 [ 854.237019] [] async_run_entry_fn+0xc6/0x173 <-- ...while running in async context Provide a 'scsi_sd_probe_domain' so that async probe actions actions can be flushed without regard for the state of PM, and allow for the resume path to handle devices that have transitioned from SDEV_QUIESCE to SDEV_DEL prior to resume. Acked-by: Alan Stern [alan: uplevel scsi_sd_probe_domain, clarify scsi_device_resume] Signed-off-by: Dan Williams [jejb: remove unneeded config guards in include file] Signed-off-by: James Bottomley

[SCSI] Handle disk devices which can not process medium access commands

2012-02-19T16:14:52Z

We have experienced several devices which fail in a fashion we do not currently handle gracefully in SCSI. After a failure these devices will respond to the SCSI primary command set (INQUIRY, TEST UNIT READY, etc.) but any command accessing the storage medium will time out. The following patch adds an callback that can be used by upper level drivers to inspect the results of an error handling command. This in turn has been used to implement additional checking in the SCSI disk driver. If a medium access command fails twice but TEST UNIT READY succeeds both times in the subsequent error handling we will offline the device. The maximum number of failed commands required to take a device offline can be tweaked in sysfs. Also add a new error flag to scsi_debug which allows this scenario to be easily reproduced. [jejb: fix up integer parsing to use kstrtouint] Signed-off-by: Martin K. Petersen Signed-off-by: James Bottomley

SCSI host lock push-down

2010-11-16T21:33:23Z

Move the mid-layer's ->queuecommand() invocation from being locked with the host lock to being unlocked to facilitate speeding up the critical path for drivers who don't need this lock taken anyway. The patch below presents a simple SCSI host lock push-down as an equivalent transformation. No locking or other behavior should change with this patch. All existing bugs and locking orders are preserved. Additionally, add one parameter to queuecommand, struct Scsi_Host * and remove one parameter from queuecommand, void (*done)(struct scsi_cmnd *) Scsi_Host* is a convenient pointer that most host drivers need anyway, and 'done' is redundant to struct scsi_cmnd->scsi_done. Minimal code disturbance was attempted with this change. Most drivers needed only two one-line modifications for their host lock push-down. Signed-off-by: Jeff Garzik Acked-by: James Bottomley Signed-off-by: Linus Torvalds

[SCSI] Fix VPD inquiry page wrapper

2010-09-16T15:48:48Z

Fix two bugs in the VPD page wrapper: - Don't return failure if the user asked for page 0 - The end of buffer check failed to account for the page header size and consequently didn't work Signed-off-by: Martin K. Petersen Cc: Stable Tree Signed-off-by: James Bottomley

[SCSI] add scsi trace core functions and put trace points

2010-04-30T17:51:10Z

Signed-off-by: Xiao Guangrong Signed-off-by: Tomohiro Kusumi Signed-off-by: Kei Tokunaga Signed-off-by: James Bottomley

scsi.c: add missing kernel-doc notation for new VPD parameters

2010-03-01T16:11:54Z

Add missing kernel-doc notation for new function parameters: Warning(drivers/scsi/scsi.c:1031): No description found for parameter 'buf' Warning(drivers/scsi/scsi.c:1031): No description found for parameter 'buf_len' Signed-off-by: Randy Dunlap Cc: James Bottomley Signed-off-by: Linus Torvalds

[SCSI] eliminate potential kmalloc failure in scsi_get_vpd_page()

2010-01-18T16:48:05Z

The best way to fix this is to eliminate the intenal kmalloc() and make the caller allocate the required amount of storage. Signed-off-by: James Bottomley