kernel/linux.git, branch v3.14.32

Linux 3.14.32

2015-02-06T14:53:31+00:00

target: Drop arbitrary maximum I/O size limit

2015-02-06T06:35:52+00:00

commit 046ba64285a4389ae5e9a7dfa253c6bff3d7c341 upstream. This patch drops the arbitrary maximum I/O size limit in sbc_parse_cdb(), which currently for fabric_max_sectors is hardcoded to 8192 (4 MB for 512 byte sector devices), and for hw_max_sectors is a backend driver dependent value. This limit is problematic because Linux initiators have only recently started to honor block limits MAXIMUM TRANSFER LENGTH, and other non-Linux based initiators (eg: MSFT Fibre Channel) can also generate I/Os larger than 4 MB in size. Currently when this happens, the following message will appear on the target resulting in I/Os being returned with non recoverable status: SCSI OP 28h with too big sectors 16384 exceeds fabric_max_sectors: 8192 Instead, drop both [fabric,hw]_max_sector checks in sbc_parse_cdb(), and convert the existing hw_max_sectors into a purely informational attribute used to represent the granuality that backend driver and/or subsystem code is splitting I/Os upon. Also, update FILEIO with an explicit FD_MAX_BYTES check in fd_execute_rw() to deal with the one special iovec limitiation case. v2 changes: - Drop hw_max_sectors check in sbc_parse_cdb() Reported-by: Lance Gropper Reported-by: Stefan Priebe Cc: Christoph Hellwig Cc: Martin K. Petersen Cc: Roland Dreier Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

workqueue: fix subtle pool management issue which can stall whole worker_pool

2015-02-06T06:35:52+00:00

commit 29187a9eeaf362d8422e62e17a22a6e115277a49 upstream. A worker_pool's forward progress is guaranteed by the fact that the last idle worker assumes the manager role to create more workers and summon the rescuers if creating workers doesn't succeed in timely manner before proceeding to execute work items. This manager role is implemented in manage_workers(), which indicates whether the worker may proceed to work item execution with its return value. This is necessary because multiple workers may contend for the manager role, and, if there already is a manager, others should proceed to work item execution. Unfortunately, the function also indicates that the worker may proceed to work item execution if need_to_create_worker() is false at the head of the function. need_to_create_worker() tests the following conditions. pending work items && !nr_running && !nr_idle The first and third conditions are protected by pool->lock and thus won't change while holding pool->lock; however, nr_running can change asynchronously as other workers block and resume and while it's likely to be zero, as someone woke this worker up in the first place, some other workers could have become runnable inbetween making it non-zero. If this happens, manage_worker() could return false even with zero nr_idle making the worker, the last idle one, proceed to execute work items. If then all workers of the pool end up blocking on a resource which can only be released by a work item which is pending on that pool, the whole pool can deadlock as there's no one to create more workers or summon the rescuers. This patch fixes the problem by removing the early exit condition from maybe_create_worker() and making manage_workers() return false iff there's already another manager, which ensures that the last worker doesn't start executing work items. We can leave the early exit condition alone and just ignore the return value but the only reason it was put there is because the manage_workers() used to perform both creations and destructions of workers and thus the function may be invoked while the pool is trying to reduce the number of workers. Now that manage_workers() is called only when more workers are needed, the only case this early exit condition is triggered is rare race conditions rendering it pointless. Tested with simulated workload and modified workqueue code which trigger the pool deadlock reliably without this patch. tj: Updated to v3.14 where manage_workers() is responsible not only for creating more workers but also destroying surplus ones. maybe_create_worker() needs to keep its early exit condition to avoid creating a new worker when manage_workers() is called to destroy surplus ones. Other than that, the adaptabion is straight-forward. Both maybe_{create|destroy}_worker() functions are converted to return void and manage_workers() returns %false iff it lost manager arbitration. Signed-off-by: Tejun Heo Reported-by: Eric Sandeen Link: http://lkml.kernel.org/g/54B019F4.8030009@sandeen.net Cc: Dave Chinner Cc: Lai Jiangshan Signed-off-by: Greg Kroah-Hartman

rbd: fix rbd_dev_parent_get() when parent_overlap == 0

2015-02-06T06:35:52+00:00

commit ae43e9d05eb4bd324155292f889fbd001c4faea8 upstream. The comment for rbd_dev_parent_get() said * We must get the reference before checking for the overlap to * coordinate properly with zeroing the parent overlap in * rbd_dev_v2_parent_info() when an image gets flattened. We * drop it again if there is no overlap. but the "drop it again if there is no overlap" part was missing from the implementation. This lead to absurd parent_ref values for images with parent_overlap == 0, as parent_ref was incremented for each img_request and virtually never decremented. Fix this by leveraging the fact that refresh path calls rbd_dev_v2_parent_info() under header_rwsem and use it for read in rbd_dev_parent_get(), instead of messing around with atomics. Get rid of barriers in rbd_dev_v2_parent_info() while at it - I don't see what they'd pair with now and I suspect we are in a pretty miserable situation as far as proper locking goes regardless. Signed-off-by: Ilya Dryomov Reviewed-by: Josh Durgin Reviewed-by: Alex Elder [idryomov@redhat.com: backport to 3.14: context] Signed-off-by: Greg Kroah-Hartman

pstore: Fix NULL pointer fault if get NULL prz in ramoops_get_next_prz

2015-02-06T06:35:52+00:00

commit b0aa931fb84431394d995472d0af2a6c2b61064d upstream. ramoops_get_next_prz get the prz according the paramters. If it get a uninitialized prz, access its members by following persistent_ram_old_size(prz) will cause a NULL pointer crash. Ex: if ftrace_size is 0, fprz will be NULL. Fix it by return NULL in advance. Signed-off-by: Liu ShuoX Acked-by: Kees Cook Signed-off-by: Tony Luck Cc: HuKeping Signed-off-by: Greg Kroah-Hartman

pstore: skip zero size persistent ram buffer in traverse

2015-02-06T06:35:52+00:00

commit aa9a4a1edfbd3d223af01db833da2f07850bc655 upstream. In ramoops_pstore_read, a valid prz pointer with zero size buffer will break traverse of all persistent ram buffers. The latter buffer might be lost. Signed-off-by: Liu ShuoX Cc: "Zhang, Yanmin" Cc: Colin Cross Reviewed-by: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Tony Luck Cc: HuKeping Signed-off-by: Greg Kroah-Hartman

pstore: clarify clearing of _read_cnt in ramoops_context

2015-02-06T06:35:51+00:00

commit 57fd835385a043577457a385f28c08be693991bf upstream. *_read_cnt in ramoops_context need to be cleared during pstore ->open to support mutli times getting the records. The patch added missed ftrace_read_cnt clearing and removed duplicate clearing in ramoops_probe. Signed-off-by: Liu ShuoX Cc: "Zhang, Yanmin" Cc: Colin Cross Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Tony Luck Cc: HuKeping Signed-off-by: Greg Kroah-Hartman

ARM: DMA: ensure that old section mappings are flushed from the TLB

2015-02-06T06:35:51+00:00

commit 6b076991dca9817e75c37e2f0db6d52611ea42fa upstream. When setting up the CMA region, we must ensure that the old section mappings are flushed from the TLB before replacing them with page tables, otherwise we can suffer from mismatched aliases if the CPU speculatively prefetches from these mappings at an inopportune time. A mismatched alias can occur when the TLB contains a section mapping, but a subsequent prefetch causes it to load a page table mapping, resulting in the possibility of the TLB containing two matching mappings for the same virtual address region. Acked-by: Will Deacon Signed-off-by: Russell King Cc: Hou Pengyang Signed-off-by: Greg Kroah-Hartman

drm/i915: Only fence tiled region of object.

2015-02-06T06:35:51+00:00

commit af1a7301c7cf8912dca03065d448c4437c5c239f upstream. When creating a fence for a tiled object, only fence the area that makes up the actual tiles. The object may be larger than the tiled area and if we allow those extra addresses to be fenced, they'll get converted to addresses beyond where the object is mapped. This opens up the possiblity of writes beyond the end of object. To prevent this, we adjust the size of the fence to only encompass the area that makes up the actual tiles. The extra space is considered un-tiled and now behaves as if it was a linear object. Testcase: igt/gem_tiled_fence_overflow Reported-by: Dan Hettena Signed-off-by: Bob Paauwe Reviewed-by: Daniel Vetter Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman

drivers: net: cpsw: discard dual emac default vlan configuration

2015-02-06T06:35:51+00:00

commit 02a54164c52ed6eca3089a0d402170fbf34d6cf5 upstream. In Dual EMAC, the default VLANs are used to segregate Rx packets between the ports, so adding the same default VLAN to the switch will affect the normal packet transfers. So returning error on addition of dual EMAC default VLANs. Even if EMAC 0 default port VLAN is added to EMAC 1, it will lead to break dual EMAC port separations. Fixes: d9ba8f9e6298 (driver: net: ethernet: cpsw: dual emac interface implementation) Reported-by: Felipe Balbi Signed-off-by: Mugunthan V N Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman