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path: root/fs/dlm/midcomms.c
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2020-09-29fs: dlm: rework receive handlingAlexander Aring
This patch reworks the current receive handling of dlm. As I tried to change the send handling to fix reorder issues I took a look into the receive handling and simplified it, it works as the following: Each connection has a preallocated receive buffer with a minimum length of 4096. On receive, the upper layer protocol will process all dlm message until there is not enough data anymore. If there exists "leftover" data at the end of the receive buffer because the dlm message wasn't fully received it will be copied to the begin of the preallocated receive buffer. Next receive more data will be appended to the previous "leftover" data and processing will begin again. This will remove a lot of code of the current mechanism. Inside the processing functionality we will ensure with a memmove() that the dlm message should be memory aligned. To have a dlm message always started at the beginning of the buffer will reduce some amount of memmove() calls because src and dest pointers are the same. The cluster attribute "buffer_size" becomes a new meaning, it's now the size of application layer receive buffer size. If this is changed during runtime the receive buffer will be reallocated. It's important that the receive buffer size has at minimum the size of the maximum possible dlm message size otherwise the received message cannot be placed inside the receive buffer size. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193Thomas Gleixner
Based on 1 normalized pattern(s): this copyrighted material is made available to anyone wishing to use modify copy or redistribute it subject to the terms and conditions of the gnu general public license v 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 45 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528170027.342746075@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2008-12-23dlm: fix up memory allocation flagsSteven Whitehouse
Use ls_allocation for memory allocations, which a cluster fs sets to GFP_NOFS. Use GFP_NOFS for allocations when no lockspace struct is available. Taking dlm locks needs to avoid calling back into the cluster fs because write-out can require taking dlm locks. Cc: Christine Caulfield <ccaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-04dlm: dlm_process_incoming_buffer() fixesAl Viro
* check that length is large enough to cover the non-variable part of message or rcom resp. (after checking that it's large enough to cover the header, of course). * kill more pointless casts Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: align midcomms message bufferFabio M. Di Nitto
gcc does not guarantee that an auto buffer is 64bit aligned. This change allows sparc64 to work. Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com> Signed-off-by: David Teigland <teigland@redhat.com>
2007-10-10[DLM] block dlm_recv in recovery transitionDavid Teigland
Introduce a per-lockspace rwsem that's held in read mode by dlm_recv threads while working in the dlm. This allows dlm_recv activity to be suspended when the lockspace transitions to, from and between recovery cycles. The specific bug prompting this change is one where an in-progress recovery cycle is aborted by a new recovery cycle. While dlm_recv was processing a recovery message, the recovery cycle was aborted and dlm_recoverd began cleaning up. dlm_recv decremented recover_locks_count on an rsb after dlm_recoverd had reset it to zero. This is fixed by suspending dlm_recv (taking write lock on the rwsem) before aborting the current recovery. The transitions to/from normal and recovery modes are simplified by using this new ability to block dlm_recv. The switch from normal to recovery mode means dlm_recv goes from processing locking messages, to saving them for later, and vice versa. Races are avoided by blocking dlm_recv when setting the flag that switches between modes. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05[DLM] rename dlm_config_info fieldsDavid Teigland
Add a "ci_" prefix to the fields in the dlm_config_info struct so that we can use macros to add configfs functions to access them (in a later patch). No functional changes in this patch, just naming changes. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-01-20[DLM] Update DLM to the latest patch levelDavid Teigland
Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>
2006-01-18[DLM] The core of the DLM for GFS2/CLVMDavid Teigland
This is the core of the distributed lock manager which is required to use GFS2 as a cluster filesystem. It is also used by CLVM and can be used as a standalone lock manager independantly of either of these two projects. It implements VAX-style locking modes. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>