BMC/Intel-BMC/linux.git/fs/gfs2/glock.h, branch dev

GFS2: Don't use ENOBUFS when ENOMEM is the correct error code

2014-01-16T10:31:13+00:00

Al Viro has tactfully pointed out that we are using the incorrect error code in some cases. This patch fixes that, and also removes the (unused) return value for glock dumping. > * gfs2_iget() - ENOBUFS instead of ENOMEM. ENOBUFS is > "No buffer space available (POSIX.1 (XSI STREAMS option))" and since > we don't support STREAMS it's probably fair game, but... what the hell? Signed-off-by: Steven Whitehouse Cc: Al Viro

GFS2: Use lockref for glocks

2013-10-15T14:18:08+00:00

Currently glocks have an atomic reference count and also a spinlock which covers various internal fields, such as the state. This intent of this patch is to replace the spinlock and the atomic reference count with a lockref structure. This contains a spinlock which we can continue to use as before, and a reference counter which is used in conjuction with the spinlock to replace the previous atomic counter. As a result of this there are some new rules for reference counting on glocks. We need to distinguish between reference count changes under gl_spin (which are now just increment or decrement of the new counter, provided the count cannot hit zero) and those which are outside of gl_spin, but which now take gl_spin internally. The conversion is relatively straight forward. There is probably some further clean up which can be done, but the priority at this stage is to make the change in as simple a manner as possible. A consequence of this change is that the reference count is being decoupled from the lru list processing. This should allow future adoption of the lru_list code with glocks in due course. The reason for using the "dead" state and not just relying on 0 being the "invalid state" is so that in due course 0 ref counts can be allowable. The intent is to eventually be able to remove the ref count changes which are currently hidden away in state_change(). Signed-off-by: Steven Whitehouse

GFS2: Remove gfs2_refresh_inode from inode creation path

2013-04-08T07:40:17+00:00

The original method for creating inodes used in GFS2 was to fill out a buffer, with all the information, and then to read that buffer into the in-core inode, using gfs2_refresh_inode() The problem with this approach is that all the inode's fields need to be calculated ahead of time, and were stored in various variables making the code rather complicated. The new approach is simply to allocate the in-core inode earlier and fill in as many fields as possible ahead of time. These can then be used to initilise the on disk representation. The code has been working towards the point where it is possible to remove gfs2_refresh_inode() because all the fields are correctly initialised ahead of time. We've now reached that milestone, and have reversed the order of setting up the in core and on disk inodes. Signed-off-by: Steven Whitehouse

GFS2: Review bug traps in glops.c

2012-11-07T13:31:07+00:00

Two of the bug traps here could really be warnings. The others are converted from BUG() to GLOCK_BUG_ON() since we'll most likely need to know the glock state in order to debug any issues which arise. As a result of this, __dump_glock has to be renamed and is no longer static. Signed-off-by: Steven Whitehouse

GFS2: dlm based recovery coordination

2012-01-11T09:23:05+00:00

This new method of managing recovery is an alternative to the previous approach of using the userland gfs_controld. - use dlm slot numbers to assign journal id's - use dlm recovery callbacks to initiate journal recovery - use a dlm lock to determine the first node to mount fs - use a dlm lock to track journals that need recovery Signed-off-by: David Teigland Signed-off-by: Steven Whitehouse

treewide: use printf not attribute__((format(printf,...)))

2011-11-01T00:30:54+00:00

Standardize the style for compiler based printf format verification. Standardized the location of __printf too. Done via script and a little typing. $ grep -rPl --include=*.[ch] -w "__attribute__" * | \ grep -vP "^(tools|scripts|include/linux/compiler-gcc.h)" | \ xargs perl -n -i -e 'local $/; while (<>) { s/\b__attribute__\s*$\s*\(\s*format\s*\(\s*printf\s*,\s*(.+)\s*,\s*(.+)\s*$\s*\)\s*\)/__printf($1, $2)/g ; print; }' [akpm@linux-foundation.org: revert arch bits] Signed-off-by: Joe Perches Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

GFS2: Automatically adjust glock min hold time

2011-07-15T08:32:11+00:00

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: Alter point of entry to glock lru list for glocks with an address_space

2011-04-20T07:59:48+00:00

Rather than allowing the glocks to be scheduled for possible reclaim as soon as they have exited the journal, this patch delays their entry to the list until the glocks in question are no longer in use. This means that we will rely on the vm for writeback of all dirty data and metadata from now on. When glocks are added to the lru list they should be freeable much faster since all the I/O required to free them should have already been completed. This should lead to much better I/O patterns under low memory conditions. Signed-off-by: Steven Whitehouse

GFS2: Fix glock deallocation race

2011-03-09T10:58:04+00:00

This patch fixes a race in deallocating glocks which was introduced in the RCU glock patch. We need to ensure that the glock count is kept correct even in the case that there is a race to add a new glock into the hash table. Also, to avoid having to wait for an RCU grace period, the glock counter can be decremented before call_rcu() is called. Signed-off-by: Steven Whitehouse

GFS2: Use RCU for glock hash table

2011-01-21T09:39:08+00:00

This has a number of advantages: - Reduces contention on the hash table lock - Makes the code smaller and simpler - Should speed up glock dumps when under load - Removes ref count changing in examine_bucket - No longer need hash chain lock in glock_put() in common case There are some further changes which this enables and which we may do in the future. One is to look at using SLAB_RCU, and another is to look at using a per-cpu counter for the per-sb glock counter, since that is touched twice in the lifetime of each glock (but only used at umount time). Signed-off-by: Steven Whitehouse Cc: Paul E. McKenney