kernel.git/fs/gfs2/glops.c, branch linux-3.17.y

GFS2: memcontrol: Spelling s/invlidate/invalidate/

2014-07-18T10:14:31Z

Signed-off-by: Geert Uytterhoeven Cc: cluster-devel@redhat.com Signed-off-by: Steven Whitehouse

Merge tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw into next

2014-06-04T15:30:10Z

Pull gfs2 updates from Steven Whitehouse: "This must be about the smallest merge window patch set ever for GFS2. It is probably also the first one without a single patch from me. That is down to a combination of factors, and I have some things in the works that are not quite ready yet, that I hope to put in next time around. Returning to what is here this time... we have 3 patches which fix various warnings. Two are bug fixes (for quotas and also a rare recovery race condition). The final patch, from Ben Marzinski, is an important change in the freeze code which has been in progress for some time. This removes the need to take and drop the transaction lock for every single transaction, when the only time it was used, was at file system freeze time. Ben's patch integrates the freeze operation into the journal flush code as an alternative with lower overheads and also lands up resolving some difficult to fix races at the same time" * tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw: GFS2: Prevent recovery before the local journal is set GFS2: fs/gfs2/file.c: kernel-doc warning fixes GFS2: fs/gfs2/bmap.c: kernel-doc warning fixes GFS2: remove transaction glock GFS2: lops.c: replace 0 by NULL for pointers GFS2: quotas not being refreshed in gfs2_adjust_quota

GFS2: remove transaction glock

2014-05-14T09:04:34Z

GFS2 has a transaction glock, which must be grabbed for every transaction, whose purpose is to deal with freezing the filesystem. Aside from this involving a large amount of locking, it is very easy to make the current fsfreeze code hang on unfreezing. This patch rewrites how gfs2 handles freezing the filesystem. The transaction glock is removed. In it's place is a freeze glock, which is cached (but not held) in a shared state by every node in the cluster when the filesystem is mounted. This lock only needs to be grabbed on freezing, and actions which need to be safe from freezing, like recovery. When a node wants to freeze the filesystem, it grabs this glock exclusively. When the freeze glock state changes on the nodes (either from shared to unlocked, or shared to exclusive), the filesystem does a special log flush. gfs2_log_flush() does all the work for flushing out the and shutting down the incore log, and then it tries to grab the freeze glock in a shared state again. Since the filesystem is stuck in gfs2_log_flush, no new transaction can start, and nothing can be written to disk. Unfreezing the filesytem simply involes dropping the freeze glock, allowing gfs2_log_flush() to grab and then release the shared lock, so it is cached for next time. However, in order for the unfreezing ioctl to occur, gfs2 needs to get a shared lock on the filesystem root directory inode to check permissions. If that glock has already been grabbed exclusively, fsfreeze will be unable to get the shared lock and unfreeze the filesystem. In order to allow the unfreeze, this patch makes gfs2 grab a shared lock on the filesystem root directory during the freeze, and hold it until it unfreezes the filesystem. The functions which need to grab a shared lock in order to allow the unfreeze ioctl to be issued now use the lock grabbed by the freeze code instead. The freeze and unfreeze code take care to make sure that this shared lock will not be dropped while another process is using it. Signed-off-by: Benjamin Marzinski Signed-off-by: Steven Whitehouse

arch: Mass conversion of smp_mb__*()

2014-04-18T12:20:48Z

Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra Acked-by: Paul E. McKenney Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar

GFS2: Move log buffer lists into transaction

2014-02-24T16:54:54Z

Over time, we hope to be able to improve the concurrency available in the log code. This is one small step towards that, by moving the buffer lists from the super block, and into the transaction structure, so that each transaction builds its own buffer lists. At transaction commit time, the buffer lists are merged into the currently accumulating transaction. That transaction then is passed into the before and after commit functions at journal flush time. Thus there should be no change in overall behaviour yet. Signed-off-by: Steven Whitehouse

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

2014-01-16T10:31:13Z

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 only a single address space for rgrps

2014-01-03T10:01:50Z

Prior to this patch, GFS2 had one address space for each rgrp, stored in the glock. This patch changes them to use a single address space in the super block. This therefore saves (sizeof(struct address_space) * nr_of_rgrps) bytes of memory and for large filesystems, that can be significant. It would be nice to be able to do something similar and merge the inode metadata address space into the same global address space. However, that is rather more complicated as the on-disk location doesn't have a 1:1 mapping with the inodes in general. So while it could be done, it will be a more complicated operation as it requires changing a lot more code paths. Signed-off-by: Steven Whitehouse

GFS2: Use range based functions for rgrp sync/invalidation

2014-01-03T10:00:31Z

Each rgrp header is represented as a single extent on disk, so we can calculate the position within the address space, since we are using address spaces mapped 1:1 to the disk. This means that it is possible to use the range based versions of filemap_fdatawrite/wait and for invalidating the page cache. Our eventual intent is to then be able to merge the address spaces used for rgrps into a single address space, rather than to have one for each glock, saving memory and reducing complexity. Since during umount, the rgrp structures are disposed of before the glocks, we need to store the extent information in the glock so that is is available for a final invalidation. This patch uses a field which is otherwise unused in rgrp glocks to do that, so that we do not have to expand the size of a glock. Signed-off-by: Steven Whitehouse

GFS2: Wait for async DIO in glock state changes

2013-12-20T10:42:08Z

We need to wait for any outstanding DIO to complete in a couple of situations. Firstly, in case we are changing out of deferred mode (in inode_go_sync) where GLF_DIRTY will not be set. That call could be prefixed with a test for gl_state == LM_ST_DEFERRED but it doesn't seem worth it bearing in mind that the test for outstanding DIO is very quick anyway, in the usual case that there is none. The second case is in inode_go_lock which will catch the cases where we have a cached EX lock, but where we grant deferred locks against it so that there is no glock state transistion. We only need to wait if the state is not deferred, since DIO is valid anyway in that state. Signed-off-by: Steven Whitehouse

GFS2: Use lockref for glocks

2013-10-15T14:18:08Z

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