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

SCSI: scsi_remove_target: fix softlockup regression on hot remove

2012-10-07T15:39:36Z

commit bc3f02a795d3b4faa99d37390174be2a75d091bd upstream. John reports: BUG: soft lockup - CPU#2 stuck for 23s! [kworker/u:8:2202] [..] Call Trace: [] scsi_remove_target+0xda/0x1f0 [] sas_rphy_remove+0x55/0x60 [] sas_rphy_delete+0x11/0x20 [] sas_port_delete+0x25/0x160 [] mptsas_del_end_device+0x183/0x270 ...introduced by commit 3b661a9 "[SCSI] fix hot unplug vs async scan race". Don't restart lookup of more stargets in the multi-target case, just arrange to traverse the list once, on the assumption that new targets are always added at the end. There is no guarantee that the target will change state in scsi_target_reap() so we can end up spinning if we restart. Acked-by: Jack Wang LKML-Reference: Reported-by: John Drescher Tested-by: John Drescher Signed-off-by: Dan Williams Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman

[SCSI] fix hot unplug vs async scan race

2012-07-20T07:58:45Z

The following crash results from cases where the end_device has been removed before scsi_sysfs_add_sdev has had a chance to run. BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 IP: [] sysfs_create_dir+0x32/0xb6 ... Call Trace: [] kobject_add_internal+0x120/0x1e3 [] ? trace_hardirqs_on+0xd/0xf [] kobject_add_varg+0x41/0x50 [] kobject_add+0x64/0x66 [] device_add+0x12d/0x63a [] ? _raw_spin_unlock_irqrestore+0x47/0x56 [] ? module_refcount+0x89/0xa0 [] scsi_sysfs_add_sdev+0x4e/0x28a [] do_scan_async+0x9c/0x145 ...teach scsi_sysfs_add_devices() to check for deleted devices() before trying to add them, and teach scsi_remove_target() how to remove targets that have not been added via device_add(). Cc: Reported-by: Dariusz Majchrzak Signed-off-by: Dan Williams Signed-off-by: James Bottomley

[SCSI] Stop accepting SCSI requests before removing a device

2012-07-20T07:58:41Z

Avoid that the code for requeueing SCSI requests triggers a crash by making sure that that code isn't scheduled anymore after a device has been removed. Also, source code inspection of __scsi_remove_device() revealed a race condition in this function: no new SCSI requests must be accepted for a SCSI device after device removal started. Signed-off-by: Bart Van Assche Reviewed-by: Mike Christie Acked-by: Tejun Heo Signed-off-by: James Bottomley

[SCSI] Fix device removal NULL pointer dereference

2012-07-20T07:58:40Z

Use blk_queue_dead() to test whether the queue is dead instead of !sdev. Since scsi_prep_fn() may be invoked concurrently with __scsi_remove_device(), keep the queuedata (sdev) pointer in __scsi_remove_device(). This patch fixes a kernel oops that can be triggered by USB device removal. See also http://www.spinics.net/lists/linux-scsi/msg56254.html. Other changes included in this patch: - Swap the blk_cleanup_queue() and kfree() calls in scsi_host_dev_release() to make that code easier to grasp. - Remove the queue dead check from scsi_run_queue() since the queue state can change anyway at any point in that function where the queue lock is not held. - Remove the queue dead check from the start of scsi_request_fn() since it is redundant with the scsi_device_online() check. Reported-by: Jun'ichi Nomura Signed-off-by: Bart Van Assche Reviewed-by: Mike Christie Reviewed-by: Tejun Heo Cc: Signed-off-by: James Bottomley

[SCSI] add new SDEV_TRANSPORT_OFFLINE state

2012-07-20T07:58:21Z

This patch adds a new state SDEV_TRANSPORT_OFFLINE. It will be used by transport classes to offline devices for cases like when the fast_io_fail/recovery_tmo fires. In those cases we want all IO to fail, and we have not yet escalated to dev_loss_tmo behavior where we are removing the devices. Currently to handle this state, transport classes are setting the scsi_device's state to running, setting their internal session/port structs state to something that indicates failed, and then failing IO from some transport check in the queuecommand. The reason for the new value is so that users can distinguish between a device failure that is a result of a transport problem vs the wide range of errors that devices get offlined for when a scsi command times out and we offline the devices there. It also fixes the confusion as to why the transport class is failing IO, but has set the device state from blocked to running. Signed-off-by: Mike Christie Signed-off-by: James Bottomley

[SCSI] scsi: Added support for adapter and firmware reset

2011-08-27T14:36:46Z

Added new sysfs attr 'host_reset' in scsi_sysfs.c to perform adapter or firmware reset as suggested by Mike Christie here: http://marc.info/?l=linux-scsi&m=127359347111167&w=2 user/application can write "adapter" or "firmware" on this attr and it will call newly added function hook in scsi_host_template to call LDD adapter or firmware reset implementation. Signed-off-by: Vikas Chaudhary Reviewed-by: Mike Christie Signed-off-by: James Bottomley

[SCSI] Fix oops caused by queue refcounting failure

2011-06-02T09:34:43Z

In certain circumstances, we can get an oops from a torn down device. Most notably this is from CD roms trying to call scsi_ioctl. The root cause of the problem is the fact that after scsi_remove_device() has been called, the queue is fully torn down. This is actually wrong since the queue can be used until the sdev release function is called. Therefore, we add an extra reference to the queue which is released in sdev->release, so the queue always exists. Reported-by: Parag Warudkar Cc: stable@kernel.org Signed-off-by: James Bottomley

[SCSI] put stricter guards on queue dead checks

2011-04-24T16:02:17Z

SCSI uses request_queue->queuedata == NULL as a signal that the queue is dying. We set this state in the sdev release function. However, this allows a small window where we release the last reference but haven't quite got to this stage yet and so something will try to take a reference in scsi_request_fn and oops. It's very rare, but we had a report here, so we're pushing this as a bug fix The actual fix is to set request_queue->queuedata to NULL in scsi_remove_device() before we drop the reference. This causes correct automatic rejects from scsi_request_fn as people who hold additional references try to submit work and prevents anything from getting a new reference to the sdev that way. Cc: stable@kernel.org Signed-off-by: James Bottomley

PM: Remove CONFIG_PM_OPS

2011-03-14T23:43:15Z

After redefining CONFIG_PM to depend on (CONFIG_PM_SLEEP || CONFIG_PM_RUNTIME) the CONFIG_PM_OPS option is redundant and can be replaced with CONFIG_PM. Signed-off-by: Rafael J. Wysocki

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2011-01-13T18:05:56Z

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits) Documentation/trace/events.txt: Remove obsolete sched_signal_send. writeback: fix global_dirty_limits comment runtime -> real-time ppc: fix comment typo singal -> signal drivers: fix comment typo diable -> disable. m68k: fix comment typo diable -> disable. wireless: comment typo fix diable -> disable. media: comment typo fix diable -> disable. remove doc for obsolete dynamic-printk kernel-parameter remove extraneous 'is' from Documentation/iostats.txt Fix spelling milisec -> ms in snd_ps3 module parameter description Fix spelling mistakes in comments Revert conflicting V4L changes i7core_edac: fix typos in comments mm/rmap.c: fix comment sound, ca0106: Fix assignment to 'channel'. hrtimer: fix a typo in comment init/Kconfig: fix typo anon_inodes: fix wrong function name in comment fix comment typos concerning "consistent" poll: fix a typo in comment ... Fix up trivial conflicts in: - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c) - fs/ext4/ext4.h Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.