kernel.git/fs/gfs2/glops.c, branch linux-3.14.y

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

GFS2: don't overrun reserved revokes

2013-08-19T08:33:16Z

When run during fsync, a gfs2_log_flush could happen between the time when gfs2_ail_flush checked the number of blocks to revoke, and when it actually started the transaction to do those revokes. This occassionally caused it to need more revokes than it reserved, causing gfs2 to crash. Instead of just reserving enough revokes to handle the blocks that currently need them, this patch makes gfs2_ail_flush reserve the maximum number of revokes it can, without increasing the total number of reserved log blocks. This patch also passes the number of reserved revokes to __gfs2_ail_flush() so that it doesn't go over its limit and cause a crash like we're seeing. Non-fsync calls to __gfs2_ail_flush will still cause a BUG() necessary revokes are skipped. Signed-off-by: Benjamin Marzinski Signed-off-by: Steven Whitehouse

GFS2: aggressively issue revokes in gfs2_log_flush

2013-06-19T08:41:59Z

This patch looks at all the outstanding blocks in all the transactions on the log, and moves the completed ones to the ail2 list. Then it issues revokes for these blocks. This will hopefully speed things up in situations where there is a lot of contention for glocks, especially if they are acquired serially. revoke_lo_before_commit will issue at most one log block's full of these preemptive revokes. The amount of reserved log space that gfs2_log_reserve() ignores has been incremented to allow for this extra block. This patch also consolidates the common revoke instructions into one function, gfs2_add_revoke(). Signed-off-by: Benjamin Marzinski Signed-off-by: Steven Whitehouse

GFS2: Add origin indicator to glock callbacks

2013-04-10T09:26:55Z

This patch adds a bool indicating whether the demote request was originated locally or remotely. This is then used by the iopen ->go_callback() to make 100% sure that it will only respond to remote callbacks. Since ->evict_inode() uses GL_NOCACHE when it attempts to get an exclusive lock on the iopen lock, this may result in extra scheduling of the workqueue in case that the exclusive promotion request failed. This patch prevents that from happening. Signed-off-by: Steven Whitehouse

gfs2: Convert uids and gids between dinodes and vfs inodes.

2013-02-13T14:15:11Z

When reading dinodes from the disk convert uids and gids into kuids and kgids to store in vfs data structures. When writing to dinodes to the disk convert kuids and kgids in the in memory structures into plain uids and gids. For now all on disk data structures are assumed to be stored in the initial user namespace. Cc: Steven Whitehouse Signed-off-by: "Eric W. Biederman"

GFS2: only use lvb on glocks that need it

2012-11-15T10:16:59Z

Save the effort of allocating, reading and writing the lvb for most glocks that do not use it. Signed-off-by: David Teigland Signed-off-by: Steven Whitehouse