Commit Graph

103 Commits

Author SHA1 Message Date
Linus Torvalds
f16a5e3478 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes:
  GFS2: Fix permissions checking for setflags ioctl()
  GFS2: Don't "get" xattrs for ACLs when ACLs are turned off
  GFS2: Rework reclaiming unlinked dinodes
2010-05-25 08:17:51 -07:00
Jens Axboe
ee9a3607fb Merge branch 'master' into for-2.6.35
Conflicts:
	fs/ext3/fsync.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:27:26 +02:00
Bob Peterson
ed4878e8a4 GFS2: Rework reclaiming unlinked dinodes
The previous patch I wrote for reclaiming unlinked dinodes
had some shortcomings and did not prevent all hangs.
This version is much cleaner and more logical, and has
passed very difficult testing.  Sorry for the churn.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-05-21 16:11:36 +01:00
Bob Peterson
cc0581bd61 GFS2: stuck in inode wait, no glocks stuck
This patch changes the lock ordering when gfs2 reclaims
unlinked dinodes, thereby avoiding a livelock.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-05-12 09:55:39 +01:00
Dmitry Monakhov
fbd9b09a17 blkdev: generalize flags for blkdev_issue_fn functions
The patch just convert all blkdev_issue_xxx function to common
set of flags. Wait/allocation semantics preserved.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-28 19:47:36 +02:00
Bob Peterson
1a0eae8848 GFS2: glock livelock
This patch fixes a couple gfs2 problems with the reclaiming of
unlinked dinodes.  First, there were a couple of livelocks where
everything would come to a halt waiting for a glock that was
seemingly held by a process that no longer existed.  In fact, the
process did exist, it just had the wrong pid number in the holder
information.  Second, there was a lock ordering problem between
inode locking and glock locking.  Third, glock/inode contention
could sometimes cause inodes to be improperly marked invalid by
iget_failed.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2010-04-14 16:48:05 +01:00
Steven Whitehouse
ea8d62dadd GFS2: Use GFP_NOFS for alloc structure
This is called under a glock, so its a good plan to use GFP_NOFS

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-02-01 10:01:34 +00:00
Steven Whitehouse
7fe3ec6fe5 GFS2: Fix previous patch
The do_div() call needs to remain.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-02-01 10:00:23 +00:00
Benjamin Marzinski
55f0b4c546 GFS2: Don't withdraw on partial rindex entries
ince gfs2 writes the rindex file a block at a time, and releases the
exclusive lock after each block, it is possible that another process
will grab the lock in the middle of the write.  Since rindex entries are
not an even divisor of blocks, that other process may see partial
entries.  On grows, this is fine.  The process can simply ignore the the
partial entires. Previously, the code withdrew when it saw partial
entries. Now it simply ignores them.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-02-01 09:59:54 +00:00
Steven Whitehouse
2c77634965 GFS2: Locking order fix in gfs2_check_blk_state
In some cases we already have the rindex lock when
we enter this function.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-12-03 11:57:41 +00:00
Anand Gadiyar
fd589a8f0a trivial: fix typo "to to" in multiple files
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-09-21 15:14:55 +02:00
Linus Torvalds
355bbd8cb8 Merge branch 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block: (29 commits)
  block: use blkdev_issue_discard in blk_ioctl_discard
  Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads
  block: don't assume device has a request list backing in nr_requests store
  block: Optimal I/O limit wrapper
  cfq: choose a new next_req when a request is dispatched
  Seperate read and write statistics of in_flight requests
  aoe: end barrier bios with EOPNOTSUPP
  block: trace bio queueing trial only when it occurs
  block: enable rq CPU completion affinity by default
  cfq: fix the log message after dispatched a request
  block: use printk_once
  cciss: memory leak in cciss_init_one()
  splice: update mtime and atime on files
  block: make blk_iopoll_prep_sched() follow normal 0/1 return convention
  cfq-iosched: get rid of must_alloc flag
  block: use interrupts disabled version of raise_softirq_irqoff()
  block: fix comment in blk-iopoll.c
  block: adjust default budget for blk-iopoll
  block: fix long lines in block/blk-iopoll.c
  block: add blk-iopoll, a NAPI like approach for block devices
  ...
2009-09-14 17:55:15 -07:00
Steven Whitehouse
86d0063656 GFS2: Whitespace fixes
Reported-by: Daniel Walker <dwalker@fifo99.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-09-14 09:50:57 +01:00
Christoph Hellwig
746cd1e7e4 block: use blkdev_issue_discard in blk_ioctl_discard
blk_ioctl_discard duplicates large amounts of code from blkdev_issue_discard,
the only difference between the two is that blkdev_issue_discard needs to
send a barrier discard request and blk_ioctl_discard a non-barrier one,
and blk_ioctl_discard needs to wait on the request.  To facilitates this
add a flags argument to blkdev_issue_discard to control both aspects of the
behaviour.  This will be very useful later on for using the waiting
funcitonality for other callers.

Based on an earlier patch from Matthew Wilcox <matthew@wil.cx>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-14 08:24:53 +02:00
Steven Whitehouse
acf7e2444a GFS2: Be extra careful about deallocating inodes
There is a potential race in the inode deallocation code if two
nodes try to deallocate the same inode at the same time. Most of
the issue is solved by the iopen locking. There is still a small
window which is not covered by the iopen lock. This patches fixes
that and also makes the deallocation code more robust in the face of
any errors in the rgrp bitmaps, or erroneous iopen callbacks from
other nodes.

This does introduce one extra disk read, but that is generally not
an issue since its the same block that must be written to later
in the deallocation process. The total disk accesses therefore stay
the same,

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-09-08 18:00:30 +01:00
Steven Whitehouse
8d8291ae93 GFS2: Remove no_formal_ino generating code
The inum structure used throughout GFS2 has two fields. One
no_addr is the disk block number of the inode in question and
is used everywhere as the inode number. The other, no_formal_ino,
is used only as the generation number for NFS.

Historically the no_formal_ino field was set using a complicated
system of one global and one per-node file containing inode numbers
in order to ensure that each no_formal_ino was unique. Also this
code made no provision for what would happen when eventually the
(64 bit) numbers ran out. Now I know that is pretty unlikely to
happen given the large space of numbers, but it is possible
nevertheless.

The only guarantee required for no_formal_ino is that, for any
single inode, the same number doesn't get reused too quickly.

We already have a generation number which is kept in the inode
and initialised from a counter in the resource group (almost
no overhead, since we have to touch the resource group anyway
in order to allocate an inode in the first place). Aside from
ensuring that we never use the value 0 in the no_formal_ino
field, we can use that counter directly.

As a result of that change, we lose about 200 lines of code and
also gain about 10 creates/sec on the postmark benchmark (on
my test machine).

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-08-27 15:51:07 +01:00
Steven Whitehouse
05164e5b37 GFS2: Replace assertion with proper error handling
One fewer assert, one more place we can recover gracefully
if there is an error.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-08-17 11:06:43 +01:00
Steven Whitehouse
6050b9c74f GFS2: Improve error handling in inode allocation
A little while back, block allocation was given some improved
error handling which meant that -EIO was returned in the case
of there being a problem in the resource group data. In addition
a message is printed explaning what went wrong and how to fix it.
This extends that error handling so that it also covers inode
allocation too.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-08-17 11:05:31 +01:00
Benjamin Marzinski
6b94617024 GFS2: Fix incorrent statfs consistency check
Since both linked and unlinked inodes are counted by rgd->rd_dinodes, It
makes no sense to count them with the used data blocks (first check that
I changed), it makes sense to count them with the linked inodes (second
check), and it makes no sense to care if there are more unlinked inodes
than linked ones. This fixes these errors.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-07-30 11:00:28 +01:00
Steven Whitehouse
1e19a19584 GFS2: Don't try and dealloc own inode
When searching for unlinked, but still allocated inodes during block
allocation, avoid the block relating to the inode that is doing the
allocation. This fixes a hang caused when an unlinked, but still
open, inode tries to allocate some more blocks and lands up
finding itself during the search for deallocatable inodes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-07-30 10:59:50 +01:00
Steven Whitehouse
63997775b7 GFS2: Add tracepoints
This patch adds the ability to trace various aspects of the GFS2
filesystem. The trace points are divided into three groups,
glocks, logging and bmap. These points have been chosen because
they allow inspection of the major internal functions of GFS2
and they are also generic enough that they are unlikely to need
any major changes as the filesystem evolves.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-06-12 08:49:20 +01:00
Linus Torvalds
c9059598ea Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits)
  block: add request clone interface (v2)
  floppy: fix hibernation
  ramdisk: remove long-deprecated "ramdisk=" boot-time parameter
  fs/bio.c: add missing __user annotation
  block: prevent possible io_context->refcount overflow
  Add serial number support for virtio_blk, V4a
  block: Add missing bounce_pfn stacking and fix comments
  Revert "block: Fix bounce limit setting in DM"
  cciss: decode unit attention in SCSI error handling code
  cciss: Remove no longer needed sendcmd reject processing code
  cciss: change SCSI error handling routines to work with interrupts enabled.
  cciss: separate error processing and command retrying code in sendcmd_withirq_core()
  cciss: factor out fix target status processing code from sendcmd functions
  cciss: simplify interface of sendcmd() and sendcmd_withirq()
  cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code
  cciss: Use schedule_timeout_uninterruptible in SCSI error handling code
  block: needs to set the residual length of a bidi request
  Revert "block: implement blkdev_readpages"
  block: Fix bounce limit setting in DM
  Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt
  ...

Manually fix conflicts with tracing updates in:
	block/blk-sysfs.c
	drivers/ide/ide-atapi.c
	drivers/ide/ide-cd.c
	drivers/ide/ide-floppy.c
	drivers/ide/ide-tape.c
	include/trace/events/block.h
	kernel/trace/blktrace.c
2009-06-11 11:10:35 -07:00
Martin K. Petersen
e1defc4ff0 block: Do away with the notion of hardsect_size
Until now we have had a 1:1 mapping between storage device physical
block size and the logical block sized used when addressing the device.
With SATA 4KB drives coming out that will no longer be the case.  The
sector size will be 4KB but the logical block size will remain
512-bytes.  Hence we need to distinguish between the physical block size
and the logical ditto.

This patch renames hardsect_size to logical_block_size.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22 23:22:54 +02:00
Steven Whitehouse
b1e71b0622 GFS2: Clean up some file names
This patch renames the ops_*.c files which have no counterpart
without the ops_ prefix in order to shorten the name and make
it more readable. In addition, ops_address.h (which was very
small) is moved into inode.h and inode.h is cleaned up by
adding extern where required.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-22 10:01:55 +01:00
Steven Whitehouse
1ce97e564b GFS2: Be more aggressive in reclaiming unlinked inodes
This patch increases the frequency with which gfs2 looks
for unlinked, but still allocated inodes. Its the equivalent
operation to ext3's orphan list, but done with bitmaps in
the resource groups.

This also fixes a bug where a field in the rgrp was too small.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-21 15:18:19 +01:00
Steven Whitehouse
60a0b8f936 GFS2: Add a rgrp bitmap full flag
During block allocation, it is useful to know if sections of disk
are full on a finer grained basis than a single resource group.
This can make a performance difference when resource groups have
larger numbers of bitmap blocks, since we no longer have to search
them all block by block in each individual bitmap.

The full flag is set on a per-bitmap basis when it has been
searched and found to have no free space. It is then skipped in
subsequent searches until the flag is reset. The resetting
occurs if we have to drop the glock on the resource group for any
reason, or if we deallocate some blocks within that resource
group and thus free up some space.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-21 12:23:12 +01:00
Steven Whitehouse
0901097834 GFS2: Improve resource group error handling
This patch improves the error handling in the case where we
discover that the summary information in the resource group
doesn't match the bitmap information while in the process of
allocating blocks. Originally this resulted in a kernel bug,
but this patch changes that so that we return -EIO and print
some messages explaining what went wrong, and how to fix it.

We also remember locally not to try and allocate from the
same rgrp again, so that a subsequent allocation in a
different rgrp should succeed.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-20 10:48:47 +01:00
Steven Whitehouse
d9ba7615bf GFS2: Ensure that the inode goal block settings are updated
GFS2 has a goal block associated with each inode indicating the
search start position for future block allocations (in fact there
are two, but thats for backward compatibility with GFS1 as they
are set to identical locations in GFS2).

In some circumstances, depending on the ordering of updates to
the inode it was possible for the goal block settings to not
be updated on disk. This patch ensures that the goal block will
always get updated, thus reducing the potential for searching
the same (already allocated) blocks again when looking for free
space during block allocation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-23 10:07:37 +01:00
Steven Whitehouse
d8bd504ab8 GFS2: Fix bug in block allocation
The new bitfit algorithm was counting from the wrong end of
64 bit words in the bitfield. This fixes it by using __ffs64
instead of fls64

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-23 10:07:16 +01:00
Hannes Eder
02ab172159 GFS2: fix sparse warning: Should it be static?
Impact: Make symbol static.

Fix this sparse warning:
  fs/gfs2/rgrp.c:188:5: warning: symbol 'gfs2_bitfit' was not declared. Should it be static?

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24 11:21:25 +00:00
Hannes Eder
075ac44875 GFS2: fix sparse warnings: constant is so big it is ...
Fix this sparse warnings:
  fs/gfs2/rgrp.c:156:23: warning: constant 0xffffffffffffffff is so big it is unsigned long long
  fs/gfs2/rgrp.c:157:23: warning: constant 0xaaaaaaaaaaaaaaaa is so big it is unsigned long long
  fs/gfs2/rgrp.c:158:23: warning: constant 0x5555555555555555 is so big it is long long
  fs/gfs2/rgrp.c:194:20: warning: constant 0x5555555555555555 is so big it is long long
  fs/gfs2/rgrp.c:204:44: warning: constant 0x5555555555555555 is so big it is long long

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24 11:21:24 +00:00
Steven Whitehouse
223b2b889f GFS2: Fix alignment issue and tidy gfs2_bitfit
An alignment issue with the existing bitfit algorithm was reported
on IA64. This patch attempts to fix that, and also to tidy up the
code a bit. There is now more documentation about how this works
and it has survived a number of different tests.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24 11:21:22 +00:00
Steven Whitehouse
64d576ba23 GFS2: Add a "demote a glock" interface to sysfs
This adds a sysfs file called demote_rq to GFS2's
per filesystem directory. Its possible to use this
file to demote arbitrary glocks in exactly the same
way as if a request had come in from a remote node.

This is intended for testing issues relating to caching
of data under glocks. Despite that, the interface is
generic enough to send requests to any type of glock,
but be careful as its not always safe to send an
arbitrary message to an arbitrary glock. For that reason
and to prevent DoS, this interface is restricted to root
only.

The messages look like this:

<type>:<glocknumber> <mode>

Example:

echo -n "2:13324 EX" >/sys/fs/gfs2/unity:myfs/demote_rq

Which means "please demote inode glock (type 2) number 13324 so that
I can get an EX (exclusive) lock". The lock modes are those which
would normally be sent by a remote node in its callback so if you
want to unlock a glock, you use EX, to demote to shared, use SH or PR
(depending on whether you like GFS2 or DLM lock modes better!).

If the glock doesn't exist, you'll get -ENOENT returned. If the
arguments don't make sense, you'll get -EINVAL returned.

The plan is that this interface will be used in combination with
the blktrace patch which I recently posted for comments although
it is, of course, still useful in its own right.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24 11:21:22 +00:00
Steven Whitehouse
f15ab5619d GFS2: Support generation of discard requests
This patch allows GFS2 to generate discard requests for blocks which are
no longer useful to the filesystem (i.e. those which have been freed as
the result of an unlink operation). The requests are generated at the
time which those blocks become available for reuse in the filesystem.

In order to use this new feature, you have to specify the "discard"
mount option. The code coalesces adjacent blocks into a single extent
when generating the discard requests, thus generating the minimum
number.

If an error occurs when the request has been sent to the block device,
then it will print a message and turn off the requests for that
filesystem. If the problem is temporary, then you can use remount to
turn the option back on again. There is also a nodiscard mount option
so that you can use remount to turn discard requests off, if required.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24 11:21:20 +00:00
Steven Whitehouse
f057f6cdf6 GFS2: Merge lock_dlm module into GFS2
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>
2009-03-24 11:21:14 +00:00
Steven Whitehouse
73f749483e GFS2: Banish struct gfs2_rgrpd_host
This patch moves the final field so that we can get rid
of struct gfs2_rgrpd_host, as promised some time ago. Also
by rearranging the fields slightly, we are able to reduce
the size of the gfs2_rgrpd structure at the same time.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05 07:39:03 +00:00
Steven Whitehouse
cfc8b54922 GFS2: Move rg_free from gfs2_rgrpd_host to gfs2_rgrpd
The second of three fields which need to move, in order
to remove the struct gfs2_rgrpd_host.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05 07:39:02 +00:00
Steven Whitehouse
d8b71f7381 GFS2: Move rg_igeneration into struct gfs2_rgrpd
This moves one of the fields of struct gfs2_rgrpd_host into
the struct gfs2_rgrpd with the eventual aim of removing
the struct rgrpd_host completely.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05 07:39:01 +00:00
Steven Whitehouse
c9e9888677 GFS2: Move i_size from gfs2_dinode_host and rename it to i_disksize
This patch moved the i_size field from the gfs2_dinode_host and
following the ext3 convention renames it i_disksize.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05 07:38:58 +00:00
Steven Whitehouse
9cabcdbd46 [GFS2] Replace rgrp "recent list" with mru list
This patch removes the "recent list" which is used during allocation
and replaces it with the (already existing) mru list used during
deletion. The "recent list" was not a true mru list leading to a number
of inefficiencies including a "next" function which made scanning the
list an order N^2 operation wrt to the number of list elements.

This should increase allocation performance with large numbers of rgrps.
Its also a useful preparation and cleanup before some further changes
which are planned in this area.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-07-10 15:54:12 +01:00
Bob Peterson
17c15da00c [GFS2] BUG: unable to handle kernel paging request at ffff81002690e000
This patch fixes bugzilla bug bz448866: gfs2: BUG: unable to
handle kernel paging request at ffff81002690e000.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-06-24 14:17:45 +01:00
Andrew Price
ad99f77778 [GFS2] Fix cast from unsigned int to s64
This fixes bz 444829 where allocating a new block caused gfs2 file systems to
report 0 bytes used in df. It was caused by a broken cast from an unsigned int
in gfs2_block_alloc() to a negative s64 in gfs2_statfs_change(). This patch
casts the unsigned int to an s64 before the unary minus is applied.

Signed-off-by: Andrew Price <andy@andrewprice.me.uk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-05-12 08:54:56 +01:00
Bob Peterson
1f466a47e8 [GFS2] Faster gfs2_bitfit algorithm
This version of the gfs2_bitfit algorithm includes the latest
suggestions from Steve Whitehouse.  It is typically eight to
ten times faster than the version we're using today.  If there
is a lot of metadata mixed in (lots of small files) the
algorithm is often 15 times faster, and given the right
conditions, I've seen peaks of 20 times faster.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:41:39 +01:00
Steven Whitehouse
9b8c81d1de [GFS2] Allow bmap to allocate extents
We've supported mapping of extents when no block allocation is required
for some time. This patch extends that to mapping of extents when an
allocation has been requested. In that case we try to allocate as many
blocks as are requested, but we might return fewer in case there is
something preventing us from returning the complete amount (e.g. an
already allocated block is in the way).

Currently the only code path which can actually request multiple data
blocks in a single bmap call is the page_mkwrite path and even then it
only happens if there are multiple blocks per page. What this patch does
do however, is merge the allocation requests for metadata (growing the
metadata tree in either height or depth) with the allocation of the data
blocks in the case that both are needed. This results in lower overheads
even in the single block allocation case.

The one thing which we can't handle here at the moment is unstuffing. I
would like to be able to do that, but the problem which arises is that
in order to unstuff one has to get a locked page from the page cache
which results in locking problems in the (usual) case that the caller is
holding the page lock on the page it wishes to map. So that case will
have to be addressed in future patches.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:41:14 +01:00
Steven Whitehouse
b45e41d7d5 [GFS2] Add extent allocation to block allocator
Rather than having to allocate a single block at a time, this patch
allows the block allocator to allocate an extent. Since there is
no difference (so far as the block allocator is concerned) between
data blocks and indirect blocks, it is posible to allocate a single
extent and for the caller to unrevoke just the blocks required
for indirect blocks.

Currently the only bit of GFS2 to make use of this feature is the
build height function. The intention is that gfs2_block_map will
be changed to make use of this feature in future patches.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:47 +01:00
Steven Whitehouse
1639431a3f [GFS2] Merge gfs2_alloc_meta and gfs2_alloc_data
Thanks to the preceeding patches, the only difference between
these two functions is their name. We can thus merge them
and call the new function gfs2_alloc_block to reflect the
fact that it can allocate either kind of block.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:45 +01:00
Steven Whitehouse
5731be53e3 [GFS2] Update gfs2_trans_add_unrevoke to accept extents
By adding an extra argument to gfs2_trans_add_unrevoke we can now
specify an extent length of blocks to unrevoke. This means that
we only need to make one pass through the list for each extent
rather than each block. Currently the only extent length which
is used is 1, but that will change in the future.

Also gfs2_trans_add_unrevoke is removed from gfs2_alloc_meta
since its the only difference between this and gfs2_alloc_data
which is left. This will allow a future patch to merge these
two functions into one (i.e. one call to allocate both data
and metadata in a single extent in the future).

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:42 +01:00
Steven Whitehouse
ac576cc5be [GFS2] Merge the rd_last_alloc_meta and rd_last_alloc_data fields
We don't need to keep track of when we last allocated data
and metadata separately since the only thing thats important
when searching for a free block is whether its free or not,
which is independent from what type of block it is.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:39 +01:00
Steven Whitehouse
ce276b06e8 [GFS2] Reduce inode size by merging fields
There were three fields being used to keep track of the location
of the most recently allocated block for each inode. These have
been merged into a single field in order to better keep the
data and metadata for an inode close on disk, and also to reduce
the space required for storage.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:37 +01:00
Bob Peterson
cf45b752c9 [GFS2] Remove rgrp and glock version numbers
This patch further reduces GFS2's memory requirements by
eliminating the 64-bit version number fields in lieu of
a couple bits.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:29 +01:00