user/sven/linux.git/kernel/power/user.c, branch v3.10.44

Make wait_for_device_probe() also do scsi_complete_async_scans()

2012-07-19T01:15:46Z

Commit a7a20d103994 ("sd: limit the scope of the async probe domain") make the SCSI device probing run device discovery in it's own async domain. However, as a result, the partition detection was no longer synchronized by async_synchronize_full() (which, despite the name, only synchronizes the global async space, not all of them). Which in turn meant that "wait_for_device_probe()" would not wait for the SCSI partitions to be parsed. And "wait_for_device_probe()" was what the boot time init code relied on for mounting the root filesystem. Now, most people never noticed this, because not only is it timing-dependent, but modern distributions all use initrd. So the root filesystem isn't actually on a disk at all. And then before they actually mount the final disk filesystem, they will have loaded the scsi-wait-scan module, which not only does the expected wait_for_device_probe(), but also does scsi_complete_async_scans(). [ Side note: scsi_complete_async_scans() had also been partially broken, but that was fixed in commit 43a8d39d0137 ("fix async probe regression"), so that same commit a7a20d103994 had actually broken setups even if you used scsi-wait-scan explicitly ] Solve this problem by just moving the scsi_complete_async_scans() call into wait_for_device_probe(). Everybody who wants to wait for device probing to finish really wants the SCSI probing to complete, so there's no reason not to do this. So now "wait_for_device_probe()" really does what the name implies, and properly waits for device probing to finish. This also removes the now unnecessary extra calls to scsi_complete_async_scans(). Reported-and-tested-by: Artem S. Tashkinov Cc: Dan Williams Cc: Alan Stern Cc: James Bottomley Cc: Borislav Petkov Cc: linux-scsi Signed-off-by: Linus Torvalds

PM / Sleep: Move disabling of usermode helpers to the freezer

2012-03-28T21:30:21Z

The core suspend/hibernation code calls usermodehelper_disable() to avoid race conditions between the freezer and the starting of usermode helpers and each code path has to do that on its own. However, it is always called right before freeze_processes() and usermodehelper_enable() is always called right after thaw_processes(). For this reason, to avoid code duplication and to make the connection between usermodehelper_disable() and the freezer more visible, make freeze_processes() call it and remove the direct usermodehelper_disable() and usermodehelper_enable() calls from all suspend/hibernation code paths. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org

PM / Hibernate: Refactor and simplify freezer_test_done

2012-02-09T22:56:01Z

The code related to 'freezer_test_done' is needlessly convoluted. Refactor the code and simplify the implementation. Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Thaw kernel threads in hibernation_snapshot() in error/test path

2012-02-09T22:55:54Z

In the hibernation call path, the kernel threads are frozen inside hibernation_snapshot(). If we happen to encounter an error further down the road or if we are exiting early due to a successful freezer test, then thaw kernel threads before returning to the caller. Signed-off-by: Srivatsa S. Bhat Acked-by: Tejun Heo Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Thaw kernel threads in SNAPSHOT_CREATE_IMAGE ioctl path

2012-02-01T21:16:36Z

In the SNAPSHOT_CREATE_IMAGE ioctl, if the call to hibernation_snapshot() fails, the frozen tasks are not thawed. And in the case of success, if we happen to exit due to a successful freezer test, all tasks (including those of userspace) are thawed, whereas actually we should have thawed only the kernel threads at that point. Fix both these issues. Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki Cc: stable@vger.kernel.org

PM / Hibernate: Fix s2disk regression related to freezing workqueues

2012-01-29T19:35:52Z

Commit 2aede851ddf08666f68ffc17be446420e9d2a056 PM / Hibernate: Freeze kernel threads after preallocating memory introduced a mechanism by which kernel threads were frozen after the preallocation of hibernate image memory to avoid problems with frozen kernel threads not responding to memory freeing requests. However, it overlooked the s2disk code path in which the SNAPSHOT_CREATE_IMAGE ioctl was run directly after SNAPSHOT_FREE, which caused freeze_workqueues_begin() to BUG(), because it saw that worqueues had been already frozen. Although in principle this issue might be addressed by removing the relevant BUG_ON() from freeze_workqueues_begin(), that would reintroduce the very problem that commit 2aede851ddf08666f68ffc17be4 attempted to avoid into that particular code path. For this reason, to fix the issue at hand, introduce thaw_kernel_threads() and make the SNAPSHOT_FREE ioctl execute it. Special thanks to Srivatsa S. Bhat for detailed analysis of the problem. Reported-and-tested-by: Jiri Slaby Signed-off-by: Rafael J. Wysocki Acked-by: Srivatsa S. Bhat Cc: stable@kernel.org

PM / Hibernate: Implement compat_ioctl for /dev/snapshot

2012-01-04T23:05:55Z

This allows uswsusp built for i386 to run on an x86_64 kernel (tested with Debian package version 1.0+20110509-2). References: http://bugs.debian.org/502816 Signed-off-by: Ben Hutchings Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Remove deprecated hibernation snapshot ioctls

2011-12-09T22:37:07Z

Several snapshot ioctls were marked for removal quite some time ago, since they were deprecated. Remove them. Suggested-by: Rafael J. Wysocki Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki

PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()

2011-12-08T22:22:29Z

Using [un]lock_system_sleep() is safer than directly using mutex_[un]lock() on 'pm_mutex', since the latter could lead to freezing failures. Hence convert all the present users of mutex_[un]lock(&pm_mutex) to use these safe APIs instead. Suggested-by: Tejun Heo Signed-off-by: Srivatsa S. Bhat Reviewed-by: Simon Horman Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Replace unintuitive 'if' condition in kernel/power/user.c with 'else'

2011-12-06T21:13:44Z

In the snapshot_ioctl() function, under SNAPSHOT_FREEZE, the code below freeze_processes() is a bit unintuitive. Improve it by replacing the second 'if' condition with an 'else' clause. Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki