0cd491a902
disconnect takes too long time if there are many locks to cancel. besides the amount of time spent on each lock cancel, there is a resched() in cfs_hash_for_each_relax(), i.e. disconnect or eviction may take unexpectedly long time. While this patch only contains the client side fixes the original fix covered changes to both the server and client code to ensure proper disconnect handling. Below details the change done on both the server and client so people can examine the disconnect behavior with both source bases. - do not cancel locks on disconnect_export; - export will be left in obd_unlinked_exports list pinned by live locks; - new re-connects will created other non-conflicting exports; - new locks will cancel obsolete locks on conflicts; - once all the locks on the disconnected export will be cancelled, the export will be destroyed on the last ref put; - do not cancel in small portions, cancel all together in just 1 dedicated thread - use server side blocking thread for that; - cancel blocked locks first so that waiting locks could proceed; - take care about blocked waiting locks, so that they would get cancelled quickly too; - do not remove lock from waiting list on AST error before moving it to elt_expired_locks list, because it removes it from export list too; otherwise this blocked lock will not be cancelled immediately on failed export; - cancel lock instead of just destroy for failed export, to make full cleanup, i.e. remove it from export list. Signed-off-by: Vitaly Fertman <vitaly_fertman@xyratex.com> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3031 Xyratex-bug-id: MRP-395 MRP-1366 MRP-1366 Reviewed-by: Andriy Skulysh <Andriy_Skulysh@xyratex.com> Reviewed-by: Alexey Lyashkov <Alexey_Lyashkov@xyratex.com> Reviewed-on: http://review.whamcloud.com/5843 Reviewed-by: James Simmons <uja.ornl@yahoo.com> Reviewed-by: Andreas Dilger <andreas.dilger@intel.com> Reviewed-by: Oleg Drokin <oleg.drokin@intel.com> Signed-off-by: James Simmons <jsimmons@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.