kernel/linux.git/include/linux, branch v4.0.8

block: discard bdi_unregister() in favour of bdi_destroy()

2015-06-23T00:03:29+00:00

commit aad653a0bc09dd4ebcb5579f9f835bbae9ef2ba3 upstream. bdi_unregister() now contains very little functionality. It contains a "WARN_ON" if bdi->dev is NULL. This warning is of no real consequence as bdi->dev isn't needed by anything else in the function, and it triggers if blk_cleanup_queue() -> bdi_destroy() is called before bdi_unregister, which happens since Commit: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.") So this isn't wanted. It also calls bdi_set_min_ratio(). This needs to be called after writes through the bdi have all been flushed, and before the bdi is destroyed. Calling it early is better than calling it late as it frees up a global resource. Calling it immediately after bdi_wb_shutdown() in bdi_destroy() perfectly fits these requirements. So bdi_unregister() can be discarded with the important content moved to bdi_destroy(), as can the writeback_bdi_unregister event which is already not used. Reported-by: Mike Snitzer Fixes: c4db59d31e39 ("fs: don't reassign dirty inodes to default_backing_dev_info") Fixes: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.") Acked-by: Peter Zijlstra (Intel) Acked-by: Dan Williams Tested-by: Nicholas Moulin Signed-off-by: NeilBrown Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

gfp: add __GFP_NOACCOUNT

2015-06-06T15:21:05+00:00

commit 8f4fc071b1926d0b20336e2b3f8ab85c94c734c5 upstream. Not all kmem allocations should be accounted to memcg. The following patch gives an example when accounting of a certain type of allocations to memcg can effectively result in a memory leak. This patch adds the __GFP_NOACCOUNT flag which if passed to kmalloc and friends will force the allocation to go through the root cgroup. It will be used by the next patch. Note, since in case of kmemleak enabled each kmalloc implies yet another allocation from the kmemleak_object cache, we add __GFP_NOACCOUNT to gfp_kmemleak_mask. Alternatively, we could introduce a per kmem cache flag disabling accounting for all allocations of a particular kind, but (a) we would not be able to bypass accounting for kmalloc then and (b) a kmem cache with this flag set could not be merged with a kmem cache without this flag, which would increase the number of global caches and therefore fragmentation even if the memory cgroup controller is not used. Despite its generic name, currently __GFP_NOACCOUNT disables accounting only for kmem allocations while user page allocations are always charged. To catch abusing of this flag, a warning is issued on an attempt of passing it to mem_cgroup_try_charge. Signed-off-by: Vladimir Davydov Cc: Tejun Heo Cc: Johannes Weiner Cc: Michal Hocko Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Greg Thelen Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

sched: Handle priority boosted tasks proper in setscheduler()

2015-06-06T15:21:04+00:00

commit 0782e63bc6fe7e2d3408d250df11d388b7799c6b upstream. Ronny reported that the following scenario is not handled correctly: T1 (prio = 10) lock(rtmutex); T2 (prio = 20) lock(rtmutex) boost T1 T1 (prio = 20) sys_set_scheduler(prio = 30) T1 prio = 30 .... sys_set_scheduler(prio = 10) T1 prio = 30 The last step is wrong as T1 should now be back at prio 20. Commit c365c292d059 ("sched: Consider pi boosting in setscheduler()") only handles the case where a boosted tasks tries to lower its priority. Fix it by taking the new effective priority into account for the decision whether a change of the priority is required. Reported-by: Ronny Meeus Tested-by: Steven Rostedt Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Steven Rostedt Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Mike Galbraith Fixes: c365c292d059 ("sched: Consider pi boosting in setscheduler()") Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1505051806060.4225@nanos Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

libata: Ignore spurious PHY event on LPM policy change

2015-06-06T15:21:02+00:00

commit 09c5b4803a80a5451d950d6a539d2eb311dc0fb1 upstream. When the LPM policy is set to ATA_LPM_MAX_POWER, the device might generate a spurious PHY event that cuases errors on the link. Ignore this event if it occured within 10s after the policy change. The timeout was chosen observing that on a Dell XPS13 9333 these spurious events can occur up to roughly 6s after the policy change. Link: http://lkml.kernel.org/g/3352987.ugV1Ipy7Z5@xps13 Signed-off-by: Gabriele Mazzotta Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

libata: Add helper to determine when PHY events should be ignored

2015-06-06T15:21:02+00:00

commit 8393b811f38acdf7fd8da2028708edad3e68ce1f upstream. This is a preparation commit that will allow to add other criteria according to which PHY events should be dropped. Signed-off-by: Gabriele Mazzotta Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

pty: Fix input race when closing

2015-06-06T15:21:01+00:00

commit 1a48632ffed61352a7810ce089dc5a8bcd505a60 upstream. A read() from a pty master may mistakenly indicate EOF (errno == -EIO) after the pty slave has closed, even though input data remains to be read. For example, pty slave | input worker | pty master | | | | n_tty_read() pty_write() | | input avail? no add data | | sleep schedule worker --->| | . |---> flush_to_ldisc() | . pty_close() | fill read buffer | . wait for worker | wakeup reader --->| . | read buffer full? |---> input avail ? yes |<--- yes - exit worker | copy 4096 bytes to user TTY_OTHER_CLOSED <---| |<--- kick worker | | **** New read() before worker starts **** | | n_tty_read() | | input avail? no | | TTY_OTHER_CLOSED? yes | | return -EIO Several conditions are required to trigger this race: 1. the ldisc read buffer must become full so the input worker exits 2. the read() count parameter must be >= 4096 so the ldisc read buffer is empty 3. the subsequent read() occurs before the kicked worker has processed more input However, the underlying cause of the race is that data is pipelined, while tty state is not; ie., data already written by the pty slave end is not yet visible to the pty master end, but state changes by the pty slave end are visible to the pty master end immediately. Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. 1. Introduce TTY_OTHER_DONE which is set by the input worker when TTY_OTHER_CLOSED is set and either the input buffers are flushed or input processing has completed. Readers/polls are woken when TTY_OTHER_DONE is set. 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. 3. A new input worker is started from pty_close() after setting TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be set if the last input worker is already finished (or just about to exit). Remove tty_flush_to_ldisc(); no in-tree callers. Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 BugLink: http://bugs.launchpad.net/bugs/1429756 Reported-by: Andy Whitcroft Reported-by: H.J. Lu Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

ktime: Fix ktime_divns to do signed division

2015-06-06T15:20:49+00:00

commit f7bcb70ebae0dcdb5a2d859b09e4465784d99029 upstream. It was noted that the 32bit implementation of ktime_divns() was doing unsigned division and didn't properly handle negative values. And when a ktime helper was changed to utilize ktime_divns, it caused a regression on some IR blasters. See the following bugzilla for details: https://bugzilla.redhat.com/show_bug.cgi?id=1200353 This patch fixes the problem in ktime_divns by checking and preserving the sign bit, and then reapplying it if appropriate after the division, it also changes the return type to a s64 to make it more obvious this is expected. Nicolas also pointed out that negative dividers would cause infinite loops on 32bit systems, negative dividers is unlikely for users of this function, but out of caution this patch adds checks for negative dividers for both 32-bit (BUG_ON) and 64-bit(WARN_ON) versions to make sure no such use cases creep in. [ tglx: Hand an u64 to do_div() to avoid the compiler warning ] Fixes: 166afb64511e 'ktime: Sanitize ktime_to_us/ms conversion' Reported-and-tested-by: Trevor Cordes Signed-off-by: John Stultz Acked-by: Nicolas Pitre Cc: Ingo Molnar Cc: Josh Boyer Cc: One Thousand Gnomes Link: http://lkml.kernel.org/r/1431118043-23452-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

fs_pin: Allow for the possibility that m_list or s_list go unused.

2015-06-06T15:20:47+00:00

commit 820f9f147dcce2602eefd9b575bbbd9ea14f0953 upstream. This is needed to support lazily umounting locked mounts. Because the entire unmounted subtree needs to stay together until there are no users with references to any part of the subtree. To support this guarantee that the fs_pin m_list and s_list nodes are initialized by initializing them in init_fs_pin allowing for the possibility that pin_insert_group does not touch them. Further use hlist_del_init in pin_remove so that there is a hlist_unhashed test before the list we attempt to update the previous list item. Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman

nilfs2: fix sanity check of btree level in nilfs_btree_root_broken()

2015-05-17T16:55:06+00:00

commit d8fd150fe3935e1692bf57c66691e17409ebb9c1 upstream. The range check for b-tree level parameter in nilfs_btree_root_broken() is wrong; it accepts the case of "level == NILFS_BTREE_LEVEL_MAX" even though the level is limited to values in the range of 0 to (NILFS_BTREE_LEVEL_MAX - 1). Since the level parameter is read from storage device and used to index nilfs_btree_path array whose element count is NILFS_BTREE_LEVEL_MAX, it can cause memory overrun during btree operations if the boundary value is set to the level parameter on device. This fixes the broken sanity check and adds a comment to clarify that the upper bound NILFS_BTREE_LEVEL_MAX is exclusive. Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

uas: Add US_FL_MAX_SECTORS_240 flag

2015-05-13T12:14:28+00:00

commit ee136af4a064c2f61e2025873584d2c7ec93f4ae upstream. The usb-storage driver sets max_sectors = 240 in its scsi-host template, for uas we do not want to do that for all devices, but testing has shown that some devices need it. This commit adds a US_FL_MAX_SECTORS_240 flag for such devices, and implements support for it in uas.c, while at it it also adds support for US_FL_MAX_SECTORS_64 to uas.c. Signed-off-by: Hans de Goede Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman