kernel.git/fs/gfs2/glops.c, branch linux-3.3.y

filesystems: add set_nlink()

2011-11-02T11:53:43Z

Replace remaining direct i_nlink updates with a new set_nlink() updater function. Signed-off-by: Miklos Szeredi Tested-by: Toshiyuki Okajima Signed-off-by: Christoph Hellwig

GFS2: Fix AIL flush issue during fsync

2011-10-21T11:39:41Z

Unfortunately, it is not enough to just ignore locked buffers during the AIL flush from fsync. We need to be able to ignore all buffers which are locked, dirty or pinned at this stage as they might have been added subsequent to the log flush earlier in the fsync function. In addition, this means that we no longer need to rely on i_mutex to keep out writes during fsync, so we can, as a side-effect, remove that protection too. Signed-off-by: Steven Whitehouse Tested-By: Abhijith Das

GFS2: Make resource groups "append only" during life of fs

2011-10-21T11:39:33Z

Since we have ruled out supporting online filesystem shrink, it is possible to make the resource group list append only during the life of a super block. This gives several benefits: Firstly, we only need to read new rindex elements as they are added rather than needing to reread the whole rindex file each time one element is added. Secondly, the rindex glock can be held for much shorter periods of time, and is completely removed from the fast path for allocations. The lock is taken in shared mode only when updating the resource groups when the first allocation occurs, and after a grow has taken place. Thirdly, this results in a reduction in code size, and everything gets a lot simpler to understand in this area. Signed-off-by: Steven Whitehouse

GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme

2011-10-21T11:39:31Z

Here is an update of Bob's original rbtree patch which, in addition, also resolves the rather strange ref counting that was being done relating to the bitmap blocks. Originally we had a dual system for journaling resource groups. The metadata blocks were journaled and also the rgrp itself was added to a list. The reason for adding the rgrp to the list in the journal was so that the "repolish clones" code could be run to update the free space, and potentially send any discard requests when the log was flushed. This was done by comparing the "cloned" bitmap with what had been written back on disk during the transaction commit. Due to this, there was a requirement to hang on to the rgrps' bitmap buffers until the journal had been flushed. For that reason, there was a rather complicated set up in the ->go_lock ->go_unlock functions for rgrps involving both a mutex and a spinlock (the ->sd_rindex_spin) to maintain a reference count on the buffers. However, the journal maintains a reference count on the buffers anyway, since they are being journaled as metadata buffers. So by moving the code which deals with the post-journal accounting for bitmap blocks to the metadata journaling code, we can entirely dispense with the rather strange buffer ref counting scheme and also the requirement to journal the rgrps. The net result of all this is that the ->sd_rindex_spin is left to do exactly one job, and that is to look after the rbtree or rgrps. This patch is designed to be a stepping stone towards using RCU for the rbtree of resource groups, however the reduction in the number of uses of the ->sd_rindex_spin is likely to have benefits for multi-threaded workloads, anyway. The patch retains ->go_lock and ->go_unlock for rgrps, however these maybe also be removed in future in favour of calling the functions directly where required in the code. That will allow locking of resource groups without needing to actually read them in - something that could be useful in speeding up statfs. In the mean time though it is valid to dereference ->bi_bh only when the rgrp is locked. This is basically the same rule as before, modulo the references not being valid until the following journal flush. Signed-off-by: Steven Whitehouse Signed-off-by: Bob Peterson Cc: Benjamin Marzinski

GFS2: Fix bug trap and journaled data fsync

2011-10-21T11:39:25Z

Journaled data requires that a complete flush of all dirty data for the file is done, in order that the ail flush which comes after will succeed. Also the recently enhanced bug trap can trigger falsely in case an ail flush from fsync races with a page read. This updates the bug trap such that it will ignore buffers which are locked and only trigger on dirty and/or pinned buffers when the ail flush is run from fsync. The original bug trap is retained when ail flush is run from ->go_sync() Signed-off-by: Steven Whitehouse

GFS2: Fix bug-trap in ail flush code

2011-10-21T11:39:20Z

The assert was being tested under the wrong lock, a legacy of the original code. Also, if it does trigger, the resulting information was not always a lot of help. This moves the patch under the correct lock and also prints out more useful information in tacking down the source of the problem. Signed-off-by: Steven Whitehouse

GFS2: Add S_NOSEC support

2011-07-15T08:32:35Z

This adds S_NOSEC support to GFS2. We set/reset the flag either when a user calls setattr or when we have just regained the glock from another node. The flag is only set if there are no xattrs on the inode and there is no suid bit set. Signed-off-by: Steven Whitehouse Reviewed-by: Andi Kleen Cc: Al Viro

GFS2: Automatically adjust glock min hold time

2011-07-15T08:32:11Z

This patch is a performance improvement for GFS2 in a clustered environment. It makes the glock hold time self-adjusting. Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse

GFS2: Cache dir hash table in a contiguous buffer

2011-07-15T08:31:48Z

This patch adds a cache for the hash table to the directory code in order to help simplify the way in which the hash table is accessed. This is intended to be a first step towards introducing some performance improvements in the directory code. There are two follow ups that I'm hoping to see fairly shortly. One is to simplify the hash table reading code now that we always read the complete hash table, whether we want one entry or all of them. The other is to introduce readahead on the heads of the hash chains which are referred to from the table. The hash table is a maximum of 128k in size, so it is not worth trying to read it in small chunks. Signed-off-by: Steven Whitehouse

GFS2: Resolve inode eviction and ail list interaction bug

2011-07-14T07:59:44Z

This patch contains a few misc fixes which resolve a recently reported issue. This patch has been a real team effort and has received a lot of testing. The first issue is that the ail lock needs to be held over a few more operations. The lock thats added into gfs2_releasepage() may possibly be a candidate for replacing with RCU at some future point, but at this stage we've gone for the obvious fix. The second issue is that gfs2_write_inode() can end up calling a glock recursively when called from gfs2_evict_inode() via the syncing code, so it needs a guard added. The third issue is that we either need to not truncate the metadata pages of inodes which have zero link count, but which we cannot deallocate due to them still being in use by other nodes, or we need to ensure that those pages have all made it through the journal and ail lists first. This patch takes the former approach, but the latter has also been tested and there is nothing to choose between them performance-wise. So again, we could revise that decision in the future. Also, the inode eviction process is now better documented. Signed-off-by: Steven Whitehouse Tested-by: Bob Peterson Tested-by: Abhijith Das Reported-by: Barry J. Marson Reported-by: David Teigland