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* GFS2: Metadata address space clean upSteven Whitehouse2010-03-011-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the start of GFS2, an "extra" inode has been used to store the metadata belonging to each inode. The only reason for using this inode was to have an extra address space, the other fields were unused. This means that the memory usage was rather inefficient. The reason for keeping each inode's metadata in a separate address space is that when glocks are requested on remote nodes, we need to be able to efficiently locate the data and metadata which relating to that glock (inode) in order to sync or sync and invalidate it (depending on the remotely requested lock mode). This patch adds a new type of glock, which has in addition to its normal fields, has an address space. This applies to all inode and rgrp glocks (but to no other glock types which remain as before). As a result, we no longer need to have the second inode. This results in three major improvements: 1. A saving of approx 25% of memory used in caching inodes 2. A removal of the circular dependency between inodes and glocks 3. No confusion between "normal" and "metadata" inodes in super.c Although the first of these is the more immediately apparent, the second is just as important as it now enables a number of clean ups at umount time. Those will be the subject of future patches. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Extend umount wait coverage to full glock lifetimeSteven Whitehouse2010-02-031-3/+3
| | | | | | | | | | | | | | Although all glocks are, by the time of the umount glock wait, scheduled for demotion, some of them haven't made it far enough through the process for the original set of waiting code to wait for them. This extends the ref count to the whole glock lifetime in order to ensure that the waiting does catch all glocks. It does make it a bit more invasive, but it seems the only sensible solution at the moment. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Wait for unlock completion on umountSteven Whitehouse2010-02-031-1/+6
| | | | | | | | | | This patch adds a wait on umount between the point at which we dispose of all glocks and the point at which we unmount the lock protocol. This ensures that we've received all the replies to our unlock requests before we stop the locking. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Reported-by: Fabio M. Di Nitto <fdinitto@redhat.com>
* GFS2: Fix locking bug in failed shared to exclusive conversionBenjamin Marzinski2009-03-241-3/+4
| | | | | | | | | | | | | | | | After calling out to the dlm, GFS2 sets the new state of a glock to gl_target in gdlm_ast(). However, gl_target is not always the lock state that was requested. If a conversion from shared to exclusive fails, finish_xmote() will call do_xmote() with LM_ST_UNLOCKED, instead of gl->gl_target, so that it can reacquire the lock in exlusive the next time around. In this case, setting the lock to gl_target in gdlm_ast() will make GFS2 think that it has the glock in exclusive mode, when really, it doesn't have the glock locked at all. This patch adds a new field to the gfs2_glock structure, gl_req, to track the mode that was requested. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Merge lock_dlm module into GFS2Steven Whitehouse2009-03-241-0/+240
This is the big patch that I've been working on for some time now. There are many reasons for wanting to make this change such as: o Reducing overhead by eliminating duplicated fields between structures o Simplifcation of the code (reduces the code size by a fair bit) o The locking interface is now the DLM interface itself as proposed some time ago. o Fewer lookups of glocks when processing replies from the DLM o Fewer memory allocations/deallocations for each glock o Scope to do further optimisations in the future (but this patch is more than big enough for now!) Please note that (a) this patch relates to the lock_dlm module and not the DLM itself, that is still a separate module; and (b) that we retain the ability to build GFS2 as a standalone single node filesystem with out requiring the DLM. This patch needs a lot of testing, hence my keeping it I restarted my -git tree after the last merge window. That way, this has the maximum exposure before its merged. This is (modulo a few minor bug fixes) the same patch that I've been posting on and off the the last three months and its passed a number of different tests so far. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
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