Commit Graph

257 Commits

Author SHA1 Message Date
Dave Chinner
2cdb958aba Merge branch 'xfs-misc-fixes-4.6-4' into for-next 2016-03-15 11:44:35 +11:00
Brian Foster
801cc4e17a xfs: debug mode forced buffered write failure
Add a DEBUG mode-only sysfs knob to enable forced buffered write
failure. An additional side effect of this mode is brute force killing
of delayed allocation blocks in the range of the write. The latter is
the prime motiviation behind this patch, as userspace test
infrastructure requires a reliable mechanism to create and split
delalloc extents without causing extent conversion.

Certain fallocate operations (i.e., zero range) were used for this in
the past, but the implementations have changed such that delalloc
extents are flushed and converted to real blocks, rendering the test
useless.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-03-15 11:42:44 +11:00
Dave Chinner
3c1a79f5ff Merge branch 'xfs-misc-fixes-4.6-2' into for-next 2016-03-07 09:34:54 +11:00
Eric Sandeen
12c3f05c7b xfs: fix up inode32/64 (re)mount handling
inode32/inode64 allocator behavior with respect to mount, remount
and growfs is a little tricky.

The inode32 mount option should only enable the inode32 allocator
heuristics if the filesystem is large enough for 64-bit inodes to
exist.  Today, it has this behavior on the initial mount, but a
remount with inode32 unconditionally changes the allocation
heuristics, even for a small fs.

Also, an inode32 mounted small filesystem should transition to the
inode32 allocator if the filesystem is subsequently grown to a
sufficient size.  Today that does not happen.

This patch consolidates xfs_set_inode32 and xfs_set_inode64 into a
single new function, and moves the "is the maximum inode number big
enough to matter" test into that function, so it doesn't rely on the
caller to get it right - which remount did not do, previously.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-03-02 09:58:09 +11:00
Eric Sandeen
de0b85a8cf xfs: remove unused function definitions
Old leftovers.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-08 14:58:07 +11:00
Dave Chinner
264e89ad34 Merge branch 'xfs-dax-updates' into for-next 2015-11-03 13:28:41 +11:00
Dave Chinner
2da5c4b05a Merge branch 'xfs-misc-fixes-for-4.4-2' into for-next 2015-11-03 13:27:58 +11:00
Darrick J. Wong
af3b63822e xfs: don't leak uuid table on rmmod
Don't leak the UUID table when the module is unloaded.
(Found with kmemleak.)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-11-03 13:06:34 +11:00
Dave Chinner
3fbbbea34b xfs: introduce BMAPI_ZERO for allocating zeroed extents
To enable DAX to do atomic allocation of zeroed extents, we need to
drive the block zeroing deep into the allocator. Because
xfs_bmapi_write() can return merged extents on allocation that were
only partially allocated (i.e. requested range spans allocated and
hole regions, allocation into the hole was contiguous), we cannot
zero the extent returned from xfs_bmapi_write() as that can
overwrite existing data with zeros.

Hence we have to drive the extent zeroing into the allocation code,
prior to where we merge the extents into the BMBT and return the
resultant map. This means we need to propagate this need down to
the xfs_alloc_vextent() and issue the block zeroing at this point.

While this functionality is being introduced for DAX, there is no
reason why it is specific to DAX - we can per-zero blocks during the
allocation transaction on any type of device. It's just slow (and
usually slower than unwritten allocation and conversion) on
traditional block devices so doesn't tend to get used. We can,
however, hook hardware zeroing optimisations via sb_issue_zeroout()
to this operation, so it may be useful in future and hence the
"allocate zeroed blocks" API needs to be implementation neutral.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-11-03 12:27:22 +11:00
Bill O'Donnell
225e463558 xfs: per-filesystem stats in sysfs
This patch implements per-filesystem stats objects in sysfs. It
depends on the application of the previous patch series that
develops the infrastructure to support both xfs global stats and
xfs per-fs stats in sysfs.

Stats objects are instantiated when an xfs filesystem is mounted
and deleted on unmount. With this patch, the stats directory is
created and populated with the familiar stats and stats_clear files.
Example:
        /sys/fs/xfs/sda9/stats/stats
        /sys/fs/xfs/sda9/stats/stats_clear

With this patch, the individual counts within the new per-fs
stats file(s) remain at zero. Functions that use the the macros
to increment, decrement, and add-to the per-fs stats counts will
be covered in a separate new patch to follow this one. Note that
the counts within the global stats file (/sys/fs/xfs/stats/stats)
advance normally and can be cleared as it was prior to this patch.

[dchinner: move setup/teardown to xfs_fs_{fill|put}_super() so
it is down before/after any path that uses the per-mount stats. ]

Signed-off-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12 18:21:19 +11:00
Dave Chinner
66e8ac7bfa Merge branch 'xfs-dax-support' into for-next 2015-06-04 13:01:49 +10:00
Dave Chinner
cbe4dab119 xfs: add initial DAX support
Add initial DAX support to XFS. To do this we need a new mount
option to turn DAX on filesystem, and we need to propagate this into
the inode flags whenever an inode is instantiated so that the
per-inode checks throughout the code Do The Right Thing.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04 09:19:18 +10:00
Brian Foster
066a18845f xfs: use sparse chunk alignment for min. inode allocation requirement
xfs_ialloc_ag_select() iterates through the allocation groups looking
for free inodes or free space to determine whether to allow an inode
allocation to proceed. If no free inodes are available, it assumes that
an AG must have an extent longer than mp->m_ialloc_blks.

Sparse inode chunk support currently allows for allocations smaller than
the traditional inode chunk size specified in m_ialloc_blks. The current
minimum sparse allocation is set in the superblock sb_spino_align field
at mkfs time. Create a new m_ialloc_min_blks field in xfs_mount and use
this to represent the minimum supported allocation size for inode
chunks. Initialize m_ialloc_min_blks at mount time based on whether
sparse inodes are supported.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-05-29 08:55:20 +10:00
Dave Chinner
964aa8d9e4 xfs: remove xfs_mod_incore_sb API
Now that there are no users of the bitfield based incore superblock
modification API, just remove the whole damn lot of it, including
all the bitfield definitions. This finally removes a lot of cruft
that has been around for a long time.

Credit goes to Christoph Hellwig for providing a great patch
connecting all the dots to enale us to do this. This patch is
derived from that work.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 21:24:37 +11:00
Dave Chinner
0bd5ddedcc xfs: replace xfs_mod_incore_sb_batched
Introduce helper functions for modifying fields in the superblock
into xfs_trans.c, the only caller of xfs_mod_incore_sb_batch().  We
can then use these directly in xfs_trans_unreserve_and_mod_sb() and
so remove another user of the xfs_mode_incore_sb() API without
losing any functionality or scalability of the transaction commit
code..

Based on a patch from Christoph Hellwig.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 21:24:11 +11:00
Dave Chinner
bab98bbe6e xfs: introduce xfs_mod_frextents
Add a new helper to modify the incore counter of free realtime
extents. This matches the helpers used for inode and data block
counters, and removes a significant users of the xfs_mod_incore_sb()
interface.

Based on a patch originally from Christoph Hellwig.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 21:22:54 +11:00
Dave Chinner
5681ca4006 xfs: Remove icsb infrastructure
Now that the in-core superblock infrastructure has been replaced with
generic per-cpu counters, we don't need it anymore. Nuke it from
orbit so we are sure that it won't haunt us again...

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 21:22:31 +11:00
Dave Chinner
0d485ada40 xfs: use generic percpu counters for free block counter
XFS has hand-rolled per-cpu counters for the superblock since before
there was any generic implementation. The free block counter is
special in that it is used for ENOSPC detection outside transaction
contexts for for delayed allocation. This means that the counter
needs to be accurate at zero. The current per-cpu counter code jumps
through lots of hoops to ensure we never run past zero, but we don't
need to make all those jumps with the generic counter
implementation.

The generic counter implementation allows us to pass a "batch"
threshold at which the addition/subtraction to the counter value
will be folded back into global value under lock. We can use this
feature to reduce the batch size as we approach 0 in a very similar
manner to the existing counters and their rebalance algorithm. If we
use a batch size of 1 as we approach 0, then every addition and
subtraction will be done against the global value and hence allow
accurate detection of zero threshold crossing.

Hence we can replace the handrolled, accurate-at-zero counters with
generic percpu counters.

Note: this removes just enough of the icsb infrastructure to compile
without warnings. The rest will go in subsequent commits.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 21:22:03 +11:00
Dave Chinner
e88b64ea1f xfs: use generic percpu counters for free inode counter
XFS has hand-rolled per-cpu counters for the superblock since before
there was any generic implementation. The free inode counter is not
used for any limit enforcement - the per-AG free inode counters are
used during allocation to determine if there are inode available for
allocation.

Hence we don't need any of the complexity of the hand-rolled
counters and we can simply replace them with generic per-cpu
counters similar to the inode counter.

This version introduces a xfs_mod_ifree() helper function from
Christoph Hellwig.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 21:19:53 +11:00
Dave Chinner
501ab32387 xfs: use generic percpu counters for inode counter
XFS has hand-rolled per-cpu counters for the superblock since before
there was any generic implementation. There are some warts around
the  use of them for the inode counter as the hand rolled counter is
designed to be accurate at zero, but has no specific accurracy at
any other value. This design causes problems for the maximum inode
count threshold enforcement, as there is no trigger that balances
the counters as they get close tothe maximum threshold.

Instead of designing new triggers for balancing, just replace the
handrolled per-cpu counter with a generic counter.  This enables us
to update the counter through the normal superblock modification
funtions, but rather than do that we add a xfs_mod_icount() helper
function (from Christoph Hellwig) and keep the percpu counter
outside the superblock in the struct xfs_mount.

This means we still need to initialise the per-cpu counter
specifically when we read the superblock, and vice versa when we
log/write it, but it does mean that we don't need to change any
other code.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 21:19:28 +11:00
Christoph Hellwig
527851124d xfs: implement pNFS export operations
Add operations to export pNFS block layouts from an XFS filesystem.  See
the previous commit adding the operations for an explanation of them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-16 11:49:23 +11:00
Dave Chinner
61e63ecb57 xfs: consolidate superblock logging functions
We now have several superblock loggin functions that are identical
except for the transaction reservation and whether it shoul dbe a
synchronous transaction or not. Consolidate these all into a single
function, a single reserveration and a sync flag and call it
xfs_sync_sb().

Also, xfs_mod_sb() is not really a modification function - it's the
operation of logging the superblock buffer. hence change the name of
it to reflect this.

Note that we have to change the mp->m_update_flags that are passed
around at mount time to a boolean simply to indicate a superblock
update is needed.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-01-22 09:10:31 +11:00
Dave Chinner
4d11a40239 xfs: remove bitfield based superblock updates
When we log changes to the superblock, we first have to write them
to the on-disk buffer, and then log that. Right now we have a
complex bitfield based arrangement to only write the modified field
to the buffer before we log it.

This used to be necessary as a performance optimisation because we
logged the superblock buffer in every extent or inode allocation or
freeing, and so performance was extremely important. We haven't done
this for years, however, ever since the lazy superblock counters
pulled the superblock logging out of the transaction commit
fast path.

Hence we have a bunch of complexity that is not necessary that makes
writing the in-core superblock to disk much more complex than it
needs to be. We only need to log the superblock now during
management operations (e.g. during mount, unmount or quota control
operations) so it is not a performance critical path anymore.

As such, remove the complex field based logging mechanism and
replace it with a simple conversion function similar to what we use
for all other on-disk structures.

This means we always log the entirity of the superblock, but again
because we rarely modify the superblock this is not an issue for log
bandwidth or CPU time. Indeed, if we do log the superblock
frequently, delayed logging will minimise the impact of this
overhead.

[Fixed gquota/pquota inode sharing regression noticed by bfoster.]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-01-22 09:10:26 +11:00
Dave Chinner
216875a594 Merge branch 'xfs-consolidate-format-defs' into for-next 2014-11-28 14:52:16 +11:00
Christoph Hellwig
4fb6e8ade2 xfs: merge xfs_ag.h into xfs_format.h
More on-disk format consolidation.  A few declarations that weren't on-disk
format related move into better suitable spots.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-11-28 14:25:04 +11:00
Brian Foster
91ee575f2b xfs: allow lazy sb counter sync during filesystem freeze sequence
The expectation since the introduction the lazy superblock counters is
that the counters are synced and superblock logged appropriately as part
of the filesystem freeze sequence. This does not occur, however, due to
the logic in xfs_fs_writable() that prevents progress when the fs is in
any state other than SB_UNFROZEN.

While this is a bug, it has not been exposed to date because the last
thing XFS does during freeze is dirty the log. The log recovery process
recalculates the counters from AGI/AGF metadata to ensure everything is
correct. Therefore should a crash occur while an fs is frozen, the
subsequent log recovery puts everything back in order. See the following
commit for reference:

	92821e2b [XFS] Lazy Superblock Counters

We might not always want to rely on dirtying the log on a frozen fs.
Modify xfs_log_sbcount() to proceed when the filesystem is freezing but
not once the freeze process has completed. Modify xfs_fs_writable() to
accept the minimum freeze level for which modifications should be
blocked to support various codepaths.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-11-28 14:02:59 +11:00
Brian Foster
78c931b8be xfs: replace global xfslogd wq with per-mount wq
The xfslogd workqueue is a global, single-job workqueue for buffer ioend
processing. This means we allow for a single work item at a time for all
possible XFS mounts on a system. fsstress testing in loopback XFS over
XFS configurations has reproduced xfslogd deadlocks due to the single
threaded nature of the queue and dependencies introduced between the
separate XFS instances by online discard (-o discard).

Discard over a loopback device converts the discard request to a hole
punch (fallocate) on the underlying file. Online discard requests are
issued synchronously and from xfslogd context in XFS, hence the xfslogd
workqueue is blocked in the upper fs waiting on a hole punch request to
be servied in the lower fs. If the lower fs issues I/O that depends on
xfslogd to complete, both filesystems end up hung indefinitely. This is
reproduced reliabily by generic/013 on XFS->loop->XFS test devices with
the '-o discard' mount option.

Further, docker implementations appear to use this kind of configuration
for container instance filesystems by default (container fs->dm->
loop->base fs) and therefore are subject to this deadlock when running
on XFS.

Replace the global xfslogd workqueue with a per-mount variant. This
guarantees each mount access to a single worker and prevents deadlocks
due to inter-fs dependencies introduced by discard. Since the queue is
only responsible for buffer iodone processing at this point in time,
rename xfslogd to xfs-buf.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-11-28 13:59:58 +11:00
Brian Foster
a31b1d3d89 xfs: add xfs_mount sysfs kobject
Embed a base kobject into xfs_mount. This creates a kobject associated
with each XFS mount and a subdirectory in sysfs with the name of the
filesystem. The subdirectory lifecycle matches that of the mount. Also
add the new xfs_sysfs.[c,h] source files with some XFS sysfs
infrastructure to facilitate attribute creation.

Note that there are currently no attributes exported as part of the
xfs_mount kobject. It exists solely to serve as a per-mount container
for child objects.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-07-15 08:07:01 +10:00
Dave Chinner
7ab610f9e0 xfs: move node entry counts to xfs_da_geometry
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-06 15:20:02 +10:00
Dave Chinner
ed358c0058 xfs: convert dir/attr btree threshold to xfs_da_geometry
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-06 15:18:10 +10:00
Dave Chinner
8f66193c89 xfs: convert m_dirblksize to xfs_da_geometry
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-06 15:15:59 +10:00
Dave Chinner
d6cf13051f xfs: convert m_dirblkfsbs to xfs_da_geometry
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-06 15:14:11 +10:00
Dave Chinner
7dda6e8644 xfs: convert directory segment limits to xfs_da_geometry
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-06 15:11:18 +10:00
Dave Chinner
0650b55497 xfs: introduce directory geometry structure
The directory code has a dependency on the struct xfs_mount to
supply the directory block geometry. Block size, block log size,
and other parameters are pre-caclulated in the struct xfs_mount or
access directly from the superblock embedded in the struct
xfs_mount.

Extract all of this geometry information out of the struct xfs_mount
and superblock and place it into a new struct xfs_da_geometry
defined by the directory code. Allocate and initialise it at mount
time, and attach it to the struct xfs_mount so it canbe passed back
into the directory code appropriately rather than using the struct
xfs_mount.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-06 15:01:58 +10:00
Dave Chinner
8f80587bac xfs: increase inode cluster size for v5 filesystems
v5 filesystems use 512 byte inodes as a minimum, so read inodes in
clusters that are effectively half the size of a v4 filesystem with
256 byte inodes. For v5 fielsystems, scale the inode cluster size
with the size of the inode so that we keep a constant 32 inodes per
cluster ratio for all inode IO.

This only works if mkfs.xfs sets the inode alignment appropriately
for larger inode clusters, so this functionality is made conditional
on mkfs doing the right thing. xfs_repair needs to know about
the inode alignment changes, too.

Wall time:
	create	bulkstat	find+stat	ls -R	unlink
v4	237s	161s		173s		201s	299s
v5	235s	163s		205s		 31s	356s
patched	234s	160s		182s		 29s	317s

System time:
	create	bulkstat	find+stat	ls -R	unlink
v4	2601s	2490s		1653s		1656s	2960s
v5	2637s	2497s		1681s		  20s	3216s
patched	2613s	2451s		1658s		  20s	3007s

So, wall time same or down across the board, system time same or
down across the board, and cache hit rates all improve except for
the ls -R case which is a pure cold cache directory read workload
on v5 filesystems...

So, this patch removes most of the performance and CPU usage
differential between v4 and v5 filesystems on traversal related
workloads.

Note: while this patch is currently for v5 filesystems only, there
is no reason it can't be ported back to v4 filesystems.  This hasn't
been done here because bringing the code back to v4 requires
forwards and backwards kernel compatibility testing.  i.e. to
deterine if older kernels(*) do the right thing with larger inode
alignments but still only using 8k inode cluster sizes. None of this
testing and validation on v4 filesystems has been done, so for the
moment larger inode clusters is limited to v5 superblocks.

(*) a current default config v4 filesystem should mount just fine on
2.6.23 (when lazy-count support was introduced), and so if we change
the alignment emitted by mkfs without a feature bit then we have to
make sure it works properly on all kernels since 2.6.23. And if we
allow it to be changed when the lazy-count bit is not set, then it's
all kernels since v2 logs were introduced that need to be tested for
compatibility...

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-11-18 09:29:36 -06:00
Dave Chinner
4bceb18f15 xfs: vectorise DA btree operations
The remaining non-vectorised code for the directory structure is the
node format blocks. This is shared with the attribute tree, and so
is slightly more complex to vectorise.

Introduce a "non-directory" directory ops structure that is attached
to all non-directory inodes so that attribute operations can be
vectorised for all inodes.

Once we do this, we can vectorise all the da btree operations.
Because this patch adds more infrastructure than it removes the
binary size does not decrease:

   text    data     bss     dec     hex filename
 794490   96802    1096  892388   d9de4 fs/xfs/xfs.o.orig
 792986   96802    1096  890884   d9804 fs/xfs/xfs.o.p1
 792350   96802    1096  890248   d9588 fs/xfs/xfs.o.p2
 789293   96802    1096  887191   d8997 fs/xfs/xfs.o.p3
 789005   96802    1096  886903   d8997 fs/xfs/xfs.o.p4
 789061   96802    1096  886959   d88af fs/xfs/xfs.o.p5
 789733   96802    1096  887631   d8b4f fs/xfs/xfs.o.p6

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-30 13:43:28 -05:00
Dave Chinner
32c5483a8a xfs: abstract the differences in dir2/dir3 via an ops vector
Lots of the dir code now goes through switches to determine what is
the correct on-disk format to parse. It generally involves a
"xfs_sbversion_hasfoo" check, deferencing the superblock version and
feature fields and hence touching several cache lines per operation
in the process. Some operations do multiple checks because they nest
conditional operations and they don't pass the information in a
direct fashion between each other.

Hence, add an ops vector to the xfs_inode structure that is
configured when the inode is initialised to point to all the correct
decode and encoding operations.  This will significantly reduce the
branchiness and cacheline footprint of the directory object decoding
and encoding.

This is the first patch in a series of conversion patches. It will
introduce the ops structure, the setup of it and add the first
operation to the vector. Subsequent patches will convert directory
ops one at a time to keep the changes simple and obvious.

Just this patch shows the benefit of such an approach on code size.
Just converting the two shortform dir operations as this patch does
decreases the built binary size by ~1500 bytes:

$ size fs/xfs/xfs.o.orig fs/xfs/xfs.o.p1
   text    data     bss     dec     hex filename
 794490   96802    1096  892388   d9de4 fs/xfs/xfs.o.orig
 792986   96802    1096  890884   d9804 fs/xfs/xfs.o.p1
$

That's a significant decrease in the instruction cache footprint of
the directory code for such a simple change, and indicates that this
approach is definitely worth pursuing further.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-30 13:37:38 -05:00
Jie Liu
0eadd10288 xfs: Introduce a new structure to hold transaction reservation items
Introduce a new structure xfs_trans_res to hold transaction
reservation item info per log ticket.

We also need to improve xfs_trans_resv_calc() by initializing the
log count as well as log flags for permanent log reservation.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12 17:45:49 -05:00
Dave Chinner
9356fe22af xfs: make struct xfs_perag kernel only
The struct xfs_perag has many kernel-only definitions in it,
requiring a __KERNEL__ guard so userspace can use it to. Move it to
xfs_mount.h so that it it kernel-only, and let userspace redefine
it's own version of the structure containing only what it needs.
This gets rid of another __KERNEL__ check in the XFS header files.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12 17:44:36 -05:00
Dave Chinner
ff55068c20 xfs: introduce xfs_sb.c for sharing with libxfs
xfs_mount.c is shared with userspace, but the only functions that
are shared are to do with physical superblock manipulations. This
means that less than 25% of the xfs_mount.c code is actually shared
with userspace. Move all the superblock functions to xfs_sb.c and
share that instead with libxfs.

Note that this will leave all the in-core transaction related
superblock counter modifications in xfs_mount.c as none of that is
shared with userspace. With a few more small changes, xfs_mount.h
won't need to be shared with userspace anymore, either.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12 16:44:11 -05:00
Dave Chinner
7fd36c4418 xfs: split out transaction reservation code
The transaction reservation size calculations is used by both kernel
and userspace, but most of the transaction code in xfs_trans.c is
kernel specific. Split all the transaction reservation code out into
it's own files to make sharing with userspace simpler. This just
leaves kernel-only definitions in xfs_trans.h, so it doesn't need to
be shared with userspace anymore, either.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12 16:36:16 -05:00
Jie Liu
39a45d8463 xfs: Remove XFS_MOUNT_RETERR
XFS_MOUNT_RETERR is going to be set at xfs_parseargs() if
mp->m_dalign is enabled, so any time we enter "if (mp->m_dalign)"
branch in xfs_update_alignment(), XFS_MOUNT_RETERR is set and so
we always be emitting a warning and returning an error.

Hence, we can remove it and get rid of a couple of redundant
check up against it at xfs_upate_alignment().

Thanks Dave Chinner for the suggestions of simplify the code
in xfs_parseargs().

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-06-19 14:54:17 -05:00
Jeff Liu
1ebdf3611c xfs: Remove struct xfs_chash from xfs_mount
Remove struct xfs_chash from struct xfs_mount as there is no user of
it nowadays.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-06-17 17:54:21 -05:00
Dave Chinner
04a1e6c5b2 xfs: add CRC checks to the superblock
With the addition of CRCs, there is such a wide and varied change to
the on disk format that it makes sense to bump the superblock
version number rather than try to use feature bits for all the new
functionality.

This commit introduces all the new superblock fields needed for all
the new functionality: feature masks similar to ext4, separate
project quota inodes, a LSN field for recovery and the CRC field.

This commit does not bump the superblock version number, however.
That will be done as a separate commit at the end of the series
after all the new functionality is present so we switch it all on in
one commit. This means that we can slowly introduce the changes
without them being active and hence maintain bisectability of the
tree.

This patch is based on a patch originally written by myself back
from SGI days, which was subsequently modified by Christoph Hellwig.
There is relatively little of that patch remaining, but the history
of the patch still should be acknowledged here.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-04-27 13:03:12 -05:00
Jeff Liu
d8ddfe81c7 xfs: Remove obsoleted m_inode_shrink from xfs_mount structure
Looks the old m_inode_shrink is obsoleted as we perform inodes reclaim per AG via
m_reclaim_workqueue, this patch remove it from the xfs_mount structure if so.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-03-14 15:55:32 -05:00
Jeff Liu
a21cd50367 xfs: refactor space log reservation for XFS_TRANS_ATTR_SET
Currently, we calculate the attribute set transaction
log space reservation at runtime in two parts:

1) XFS_ATTRSET_LOG_RES() which is calcuated out at mount time.

2) ((ext * (mp)->m_sb.sb_sectsize) + \
    (ext * XFS_FSB_TO_B((mp), XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK))) + \
    (128 * (ext + (ext * XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK))))))
which is calculated out at runtime since it depend on the given extent length in blocks.

This patch renamed XFS_ATTRSET_LOG_RES(mp) to XFS_ATTRSETM_LOG_RES(mp) to indicate
that it is figured out at mount time.  Introduce XFS_ATTRSETRT_LOG_RES(mp) which would
be used to calculate out the unit of the log space reservation for one block.

In this way, the total runtime space for the given extent length can be figured out by:
XFS_ATTRSETM_LOG_RES(mp) + XFS_ATTRSETRT_LOG_RES(mp) * ext

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-02-01 14:56:31 -06:00
Jeff Liu
a7bd794a0f xfs: introduce XFS_SB_LOG_RES() for transactions that modify sb on disk
Introduce a new transaction space reservation XFS_SB_LOG_RES() for
those transactions that need to modify the superblock on disk.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-02-01 14:46:35 -06:00
Jeff Liu
762d7ba657 xfs: calculate XFS_TRANS_QM_QUOTAOFF_END space log reservation at mount time
Convert the calculation for end of quotaoff log space reservation
from runtime to mount time.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-02-01 14:45:50 -06:00
Jeff Liu
a1bd955754 xfs: calculate XFS_TRANS_QM_QUOTAOFF space log reservation at mount time
Convert the calculation of quota off transaction log space reservation
from runtime to mount time.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-02-01 14:44:29 -06:00
Jeff Liu
4800104438 xfs: calculate XFS_TRANS_QM_DQALLOC space log reservation at mount time
The disk quota allocation log space reservation is calcuated at runtime,
this patch does it at mount time.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-02-01 14:43:51 -06:00
Jeff Liu
f0f2df94fa xfs: calcuate XFS_TRANS_QM_SETQLIM space log reservation at mount time
For adjusting quota limits transactions, we calculate out the log space
reservation at runtime, this patch does it at mount time.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-02-01 14:43:11 -06:00
Jeff Liu
b0c10b983a xfs: calculate XFS_TRANS_QM_SBCHANGE space log reservation at mount time
The transaction log space for clearing/reseting the quota flags
is calculated out at runtime, this patch can figure it out at
mount time.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-02-01 14:40:17 -06:00
Dave Chinner
1813dd6405 xfs: convert buffer verifiers to an ops structure.
To separate the verifiers from iodone functions and associate read
and write verifiers at the same time, introduce a buffer verifier
operations structure to the xfs_buf.

This avoids the need for assigning the write verifier, clearing the
iodone function and re-running ioend processing in the read
verifier, and gets rid of the nasty "b_pre_io" name for the write
verifier function pointer. If we ever need to, it will also be
easier to add further content specific callbacks to a buffer with an
ops structure in place.

We also avoid needing to export verifier functions, instead we
can simply export the ops structures for those that are needed
outside the function they are defined in.

This patch also fixes a directory block readahead verifier issue
it exposed.

This patch also adds ops callbacks to the inode/alloc btree blocks
initialised by growfs. These will need more work before they will
work with CRCs.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:35:12 -06:00
Dave Chinner
b0f539de9f xfs: connect up write verifiers to new buffers
Metadata buffers that are read from disk have write verifiers
already attached to them, but newly allocated buffers do not. Add
appropriate write verifiers to all new metadata buffers.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:35:09 -06:00
Dave Chinner
98021821a5 xfs: verify superblocks as they are read from disk
Add a superblock verify callback function and pass it into the
buffer read functions. Remove the now redundant verification code
that is currently in use.

Adding verification shows that secondary superblocks never have
their "sb_inprogress" flag cleared by mkfs.xfs, so when validating
the secondary superblocks during a grow operation we have to avoid
checking this field. Even if we fix mkfs, we will still have to
ignore this field for verification purposes unless a version of mkfs
that does not have this bug was used.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:07 -06:00
Brian Foster
579b62faa5 xfs: add background scanning to clear eofblocks inodes
Create a new mount workqueue and delayed_work to enable background
scanning and freeing of eofblocks inodes. The scanner kicks in once
speculative preallocation occurs and stops requeueing itself when
no eofblocks inodes exist.

The scan interval is based on the new
'speculative_prealloc_lifetime' tunable (default to 5m). The
background scanner performs unfiltered, best effort scans (which
skips inodes under lock contention or with a dirty cache mapping).

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:34:59 -06:00
Dave Chinner
6d8b79cfca xfs: rename xfs_sync.[ch] to xfs_icache.[ch]
xfs_sync.c now only contains inode reclaim functions and inode cache
iteration functions. It is not related to sync operations anymore.
Rename to xfs_icache.c to reflect it's contents and prepare for
consolidation with the other inode cache file that exists
(xfs_iget.c).

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17 13:40:09 -05:00
Dave Chinner
5889608df3 xfs: syncd workqueue is no more
With the syncd functions moved to the log and/or removed, the syncd
workqueue is the only remaining bit left. It is used by the log
covering/ail pushing work, as well as by the inode reclaim work.

Given how cheap workqueues are these days, give the log and inode
reclaim work their own work queues and kill the syncd work queue.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17 12:19:27 -05:00
Dave Chinner
9aa05000f2 xfs: xfs_sync_data is redundant.
We don't do any data writeback from XFS any more - the VFS is
completely responsible for that, including for freeze. We can
replace the remaining caller with a VFS level function that
achieves the same thing, but without conflicting with current
writeback work.

This means we can remove the flush_work and xfs_flush_inodes() - the
VFS functionality completely replaces the internal flush queue for
doing this writeback work in a separate context to avoid stack
overruns.

This does have one complication - it cannot be called with page
locks held.  Hence move the flushing of delalloc space when ENOSPC
occurs back up into xfs_file_aio_buffered_write when we don't hold
any locks that will stall writeback.

Unfortunately, writeback_inodes_sb_if_idle() is not sufficient to
trigger delalloc conversion fast enough to prevent spurious ENOSPC
whent here are hundreds of writers, thousands of small files and GBs
of free RAM.  Hence we need to use sync_sb_inodes() to block callers
while we wait for writeback like the previous xfs_flush_inodes
implementation did.

That means we have to hold the s_umount lock here, but because this
call can nest inside i_mutex (the parent directory in the create
case, held by the VFS), we have to use down_read_trylock() to avoid
potential deadlocks. In practice, this trylock will succeed on
almost every attempt as unmount/remount type operations are
exceedingly rare.

Note: we always need to pass a count of zero to
generic_file_buffered_write() as the previously written byte count.
We only do this by accident before this patch by the virtue of ret
always being zero when there are no errors. Make this explicit
rather than needing to specifically zero ret in the ENOSPC retry
case.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17 12:01:25 -05:00
Dave Chinner
f661f1e0bf xfs: sync work is now only periodic log work
The only thing the periodic sync work does now is flush the AIL and
idle the log. These are really functions of the log code, so move
the work to xfs_log.c and rename it appropriately.

The only wart that this leaves behind is the xfssyncd_centisecs
sysctl, otherwise the xfssyncd is dead. Clean up any comments that
related to xfssyncd to reflect it's passing.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17 11:53:29 -05:00
Alex Elder
1ed845df60 xfs: kill struct declarations in xfs_mount.h
I noticed that "struct xfs_mount_args" was still declared in
"fs/xfs/xfs_mount.h".  That struct doesn't even exist any more (and
is obviously not referenced elsewhere in that header file).  While
in there, delete four other unneeded struct declarations in that
file.

Doing so highlights that "fs/xfs/xfs_trace.h" was relying indirectly
on "xfs_mount.h" to be #included in order to declare "struct
xfs_bmbt_irec", so add that declaration to resolve that issue.

Signed-off-by: Alex Elder <elder@inktank.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-08-16 13:29:35 -05:00
Linus Torvalds
a0e881b7c1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second vfs pile from Al Viro:
 "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
  deadlock reproduced by xfstests 068), symlink and hardlink restriction
  patches, plus assorted cleanups and fixes.

  Note that another fsfreeze deadlock (emergency thaw one) is *not*
  dealt with - the series by Fernando conflicts a lot with Jan's, breaks
  userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
  for massive vfsmount leak; this is going to be handled next cycle.
  There probably will be another pull request, but that stuff won't be
  in it."

Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
  delousing target_core_file a bit
  Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
  fs: Remove old freezing mechanism
  ext2: Implement freezing
  btrfs: Convert to new freezing mechanism
  nilfs2: Convert to new freezing mechanism
  ntfs: Convert to new freezing mechanism
  fuse: Convert to new freezing mechanism
  gfs2: Convert to new freezing mechanism
  ocfs2: Convert to new freezing mechanism
  xfs: Convert to new freezing code
  ext4: Convert to new freezing mechanism
  fs: Protect write paths by sb_start_write - sb_end_write
  fs: Skip atime update on frozen filesystem
  fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
  fs: Improve filesystem freezing handling
  switch the protection of percpu_counter list to spinlock
  nfsd: Push mnt_want_write() outside of i_mutex
  btrfs: Push mnt_want_write() outside of i_mutex
  fat: Push mnt_want_write() outside of i_mutex
  ...
2012-08-01 10:26:23 -07:00
Jan Kara
d9457dc056 xfs: Convert to new freezing code
Generic code now blocks all writers from standard write paths. So we add
blocking of all writers coming from ioctl (we get a protection of ioctl against
racing remount read-only as a bonus) and convert xfs_file_aio_write() to a
non-racy freeze protection. We also keep freeze protection on transaction
start to block internal filesystem writes such as removal of preallocated
blocks.

CC: Ben Myers <bpm@sgi.com>
CC: Alex Elder <elder@kernel.org>
CC: xfs@oss.sgi.com
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 09:45:48 +04:00
Mark Tinguely
f7bdf03a99 xfs: rename log structure to xlog
Rename the XFS log structure to xlog to help crash distinquish it from the
other logs in Linux.

Signed-off-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-06-21 14:21:11 -05:00
Mark Tinguely
ad223e6030 xfs: rename log structure to xlog
Rename the XFS log structure to xlog to help crash distinquish it from the
other logs in Linux.

Signed-off-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-06-21 13:49:39 -05:00
Dave Chinner
32972383ca xfs: make largest supported offset less shouty
XFS_MAXIOFFSET() is just a simple macro that resolves to
mp->m_maxioffset. It doesn't need to exist, and it just makes the
code unnecessarily loud and shouty.

Make it quiet and easy to read.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-06-14 12:28:24 -05:00
Dave Chinner
d2c2819117 xfs: m_maxioffset is redundant
The m_maxioffset field in the struct xfs_mount contains the same
value as the superblock s_maxbytes field. There is no need to carry
two copies of this limit around, so use the VFS superblock version.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-06-14 12:28:22 -05:00
Dave Chinner
4c2d542f2e xfs: Do background CIL flushes via a workqueue
Doing background CIL flushes adds significant latency to whatever
async transaction that triggers it. To avoid blocking async
transactions on things like waiting for log buffer IO to complete,
move the CIL push off into a workqueue.  By moving the push work
into a workqueue, we remove all the latency that the commit adds
from the foreground transaction commit path. This also means that
single threaded workloads won't do the CIL push procssing, leaving
them more CPU to do more async transactions.

To do this, we need to keep track of the sequence number we have
pushed work for. This avoids having many transaction commits
attempting to schedule work for the same sequence, and ensures that
we only ever have one push (background or forced) in progress at a
time. It also means that we don't need to take the CIL lock in write
mode to check for potential background push races, which reduces
lock contention.

To avoid potential issues with "smart" IO schedulers, don't use the
workqueue for log force triggered flushes. Instead, do them directly
so that the log IO is done directly by the process issuing the log
force and so doesn't get stuck on IO elevator queue idling
incorrectly delaying the log IO from the workqueue.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14 16:20:34 -05:00
Christoph Hellwig
211e4d434b xfs: implement freezing by emptying the AIL
Now that we write back all metadata either synchronously or through
the AIL we can simply implement metadata freezing in terms of
emptying the AIL.

The implementation for this is fairly simply and straight-forward:
A new routine is added that asks the xfsaild to push the AIL to the
end and waits for it to complete and send a wakeup. The routine will
then loop if the AIL is not actually empty, and continue to do so
until the AIL is compeltely empty.

We keep an inode reclaim pass in the freeze process to avoid having
memory pressure have to reclaim inodes that require dirtying the
filesystem to be reclaimed after the freeze has completed. This
means we can also treat unmount in the exact same way as freeze.

As an upside we can now remove the radix tree based inode writeback
and xfs_unmountfs_writesb.

[ Dave Chinner:
	- Cleaned up commit message.
	- Added inode reclaim passes back into freeze.
	- Cleaned up wakeup mechanism to avoid the use of a new
	  sleep counter variable. ]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14 16:20:27 -05:00
Christoph Hellwig
aa6bf01d39 xfs: use per-filesystem I/O completion workqueues
The new concurrency managed workqueues are cheap enough that we can create
per-filesystem instead of global workqueues.  This allows us to remove the
trylock or defer scheme on the ilock, which is not helpful once we have
outstanding log reservations until finishing a size update.

Also allow the default concurrency on this workqueues so that I/O completions
blocking on the ilock for one inode do not block process for another inode.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-03-05 11:07:42 -06:00
Chandra Seetharaman
6bd92a239f Change xfs_sb_from_disk() interface to take a mount pointer
Change xfs_sb_from_disk() interface to take a mount pointer
instead of a superblock pointer.

This is to print mount point specific error messages in future
fixes.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-02-03 11:21:33 -06:00
Christoph Hellwig
93b8a5854f xfs: remove the deprecated nodelaylog option
The delaylog mode has been the default for a long time, and the nodelaylog
option has been scheduled for removal in Linux 3.3.  Remove it and code
only used by it now that we have opened the 3.3 window.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2011-12-08 12:30:32 -06:00
Chandra Seetharaman
adab0f67d1 xfs: Remove the second parameter to xfs_sb_count()
Remove the second parameter to xfs_sb_count() since all callers of
the function set them.

Also, fix the header comment regarding it being called periodically.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-07-20 18:35:03 -05:00
Christoph Hellwig
e84661aa84 xfs: add online discard support
Now that we have reliably tracking of deleted extents in a
transaction we can easily implement "online" discard support
which calls blkdev_issue_discard once a transaction commits.

The actual discard is a two stage operation as we first have
to mark the busy extent as not available for reuse before we
can start the actual discard.  Note that we don't bother
supporting discard for the non-delaylog mode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-24 11:17:13 -05:00
Dave Chinner
a7b339f1b8 xfs: introduce background inode reclaim work
Background inode reclaim needs to run more frequently that the XFS
syncd work is run as 30s is too long between optimal reclaim runs.
Add a new periodic work item to the xfs syncd workqueue to run a
fast, non-blocking inode reclaim scan.

Background inode reclaim is kicked by the act of marking inodes for
reclaim.  When an AG is first marked as having reclaimable inodes,
the background reclaim work is kicked. It will continue to run
periodically untill it detects that there are no more reclaimable
inodes. It will be kicked again when the first inode is queued for
reclaim.

To ensure shrinker based inode reclaim throttles to the inode
cleaning and reclaim rate but still reclaim inodes efficiently, make it kick the
background inode reclaim so that when we are low on memory we are
trying to reclaim inodes as efficiently as possible. This kick shoul
d not be necessary, but it will protect against failures to kick the
background reclaim when inodes are first dirtied.

To provide the rate throttling, make the shrinker pass do
synchronous inode reclaim so that it blocks on inodes under IO. This
means that the shrinker will reclaim inodes rather than just
skipping over them, but it does not adversely affect the rate of
reclaim because most dirty inodes are already under IO due to the
background reclaim work the shrinker kicked.

These two modifications solve one of the two OOM killer invocations
Chris Mason reported recently when running a stress testing script.
The particular workload trigger for the OOM killer invocation is
where there are more threads than CPUs all unlinking files in an
extremely memory constrained environment. Unlike other solutions,
this one does not have a performance impact on performance when
memory is not constrained or the number of concurrent threads
operating is <= to the number of CPUs.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-04-08 12:45:07 +10:00
Dave Chinner
89e4cb550a xfs: convert ENOSPC inode flushing to use new syncd workqueue
On of the problems with the current inode flush at ENOSPC is that we
queue a flush per ENOSPC event, regardless of how many are already
queued. Thi can result in    hundreds of queued flushes, most of
which simply burn CPU scanned and do no real work. This simply slows
down allocation at ENOSPC.

We really only need one active flush at a time, and we can easily
implement that via the new xfs_syncd_wq. All we need to do is queue
a flush if one is not already active, then block waiting for the
currently active flush to complete. The result is that we only ever
have a single ENOSPC inode flush active at a time and this greatly
reduces the overhead of ENOSPC processing.

On my 2p test machine, this results in tests exercising ENOSPC
conditions running significantly faster - 042 halves execution time,
083 drops from 60s to 5s, etc - while not introducing test
regressions.

This allows us to remove the old xfssyncd threads and infrastructure
as they are no longer used.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-04-08 12:45:07 +10:00
Dave Chinner
c6d09b666d xfs: introduce a xfssyncd workqueue
All of the work xfssyncd does is background functionality. There is
no need for a thread per filesystem to do this work - it can al be
managed by a global workqueue now they manage concurrency
effectively.

Introduce a new gglobal xfssyncd workqueue, and convert the periodic
work to use this new functionality. To do this, use a delayed work
construct to schedule the next running of the periodic sync work
for the filesystem. When the sync work is complete, queue a new
delayed work for the next running of the sync work.

For laptop mode, we wait on completion for the sync works, so ensure
that the sync work queuing interface can flush and wait for work to
complete to enable the work queue infrastructure to replace the
current sequence number and wakeup that is used.

Because the sync work does non-trivial amounts of work, mark the
new work queue as CPU intensive.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-04-08 12:45:07 +10:00
Dave Chinner
055388a318 xfs: dynamic speculative EOF preallocation
Currently the size of the speculative preallocation during delayed
allocation is fixed by either the allocsize mount option of a
default size. We are seeing a lot of cases where we need to
recommend using the allocsize mount option to prevent fragmentation
when buffered writes land in the same AG.

Rather than using a fixed preallocation size by default (up to 64k),
make it dynamic by basing it on the current inode size. That way the
EOF preallocation will increase as the file size increases.  Hence
for streaming writes we are much more likely to get large
preallocations exactly when we need it to reduce fragementation.

For default settings, the size of the initial extents is determined
by the number of parallel writers and the amount of memory in the
machine. For 4GB RAM and 4 concurrent 32GB file writes:

EXT: FILE-OFFSET           BLOCK-RANGE          AG AG-OFFSET                 TOTAL
   0: [0..1048575]:         1048672..2097247      0 (1048672..2097247)      1048576
   1: [1048576..2097151]:   5242976..6291551      0 (5242976..6291551)      1048576
   2: [2097152..4194303]:   12583008..14680159    0 (12583008..14680159)    2097152
   3: [4194304..8388607]:   25165920..29360223    0 (25165920..29360223)    4194304
   4: [8388608..16777215]:  58720352..67108959    0 (58720352..67108959)    8388608
   5: [16777216..33554423]: 117440584..134217791  0 (117440584..134217791) 16777208
   6: [33554424..50331511]: 184549056..201326143  0 (184549056..201326143) 16777088
   7: [50331512..67108599]: 251657408..268434495  0 (251657408..268434495) 16777088

and for 16 concurrent 16GB file writes:

 EXT: FILE-OFFSET           BLOCK-RANGE          AG AG-OFFSET                 TOTAL
   0: [0..262143]:          2490472..2752615      0 (2490472..2752615)       262144
   1: [262144..524287]:     6291560..6553703      0 (6291560..6553703)       262144
   2: [524288..1048575]:    13631592..14155879    0 (13631592..14155879)     524288
   3: [1048576..2097151]:   30408808..31457383    0 (30408808..31457383)    1048576
   4: [2097152..4194303]:   52428904..54526055    0 (52428904..54526055)    2097152
   5: [4194304..8388607]:   104857704..109052007  0 (104857704..109052007)  4194304
   6: [8388608..16777215]:  209715304..218103911  0 (209715304..218103911)  8388608
   7: [16777216..33554423]: 452984848..469762055  0 (452984848..469762055) 16777208

Because it is hard to take back specualtive preallocation, cases
where there are large slow growing log files on a nearly full
filesystem may cause premature ENOSPC. Hence as the filesystem nears
full, the maximum dynamic prealloc size іs reduced according to this
table (based on 4k block size):

freespace       max prealloc size
  >5%             full extent (8GB)
  4-5%             2GB (8GB >> 2)
  3-4%             1GB (8GB >> 3)
  2-3%           512MB (8GB >> 4)
  1-2%           256MB (8GB >> 5)
  <1%            128MB (8GB >> 6)

This should reduce the amount of space held in speculative
preallocation for such cases.

The allocsize mount option turns off the dynamic behaviour and fixes
the prealloc size to whatever the mount option specifies. i.e. the
behaviour is unchanged.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
2011-01-04 11:35:03 +11:00
Christoph Hellwig
6c77b0ea1b xfs: remove xfs_cred.h
We're not actually passing around credentials inside XFS for a while
now, so remove all xfs_cred.h with it's cred_t typedef and all
instances of it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18 15:08:06 -05:00
Christoph Hellwig
96540c7858 xfs: do not use xfs_mod_incore_sb for per-cpu counters
Export xfs_icsb_modify_counters and always use it for modifying
the per-cpu counters.  Remove support for per-cpu counters from
xfs_mod_incore_sb to simplify it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18 15:07:59 -05:00
Christoph Hellwig
61ba35dea0 xfs: remove XFS_MOUNT_NO_PERCPU_SB
Fail the mount if we can't allocate memory for the per-CPU counters.
This is consistent with how we handle everything else in the mount
path and makes the superblock counter modification a lot simpler.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18 15:07:58 -05:00
Dave Chinner
65d0f20533 xfs: split inode AG walking into separate code for reclaim
The reclaim walk requires different locking and has a slightly
different walk algorithm, so separate it out so that it can be
optimised separately.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18 15:07:52 -05:00
Christoph Hellwig
a64afb057b xfs: remove obsolete osyncisosync mount option
Since Linux 2.6.33 the kernel has support for real O_SYNC, which made
the osyncisosync option a no-op.  Warn the users about this and remove
the mount flag for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2010-07-26 13:16:51 -05:00
Christoph Hellwig
288699feca xfs: drop dmapi hooks
Dmapi support was never merged upstream, but we still have a lot of hooks
bloating XFS for it, all over the fast pathes of the filesystem.

This patch drops over 700 lines of dmapi overhead.  If we'll ever get HSM
support in mainline at least the namespace events can be done much saner
in the VFS instead of the individual filesystem, so it's not like this
is much help for future work.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-07-26 13:16:33 -05:00
Dave Chinner
70e60ce715 xfs: convert inode shrinker to per-filesystem contexts
Now the shrinker passes us a context, wire up a shrinker context per
filesystem. This allows us to remove the global mount list and the
locking problems that introduced. It also means that a shrinker call
does not need to traverse clean filesystems before finding a
filesystem with reclaimable inodes.  This significantly reduces
scanning overhead when lots of filesystems are present.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-07-20 08:07:02 +10:00
Dave Chinner
71e330b593 xfs: Introduce delayed logging core code
The delayed logging code only changes in-memory structures and as
such can be enabled and disabled with a mount option. Add the mount
option and emit a warning that this is an experimental feature that
should not be used in production yet.

We also need infrastructure to track committed items that have not
yet been written to the log. This is what the Committed Item List
(CIL) is for.

The log item also needs to be extended to track the current log
vector, the associated memory buffer and it's location in the Commit
Item List. Extend the log item and log vector structures to enable
this tracking.

To maintain the current log format for transactions with delayed
logging, we need to introduce a checkpoint transaction and a context
for tracking each checkpoint from initiation to transaction
completion.  This includes adding a log ticket for tracking space
log required/used by the context checkpoint.

To track all the changes we need an io vector array per log item,
rather than a single array for the entire transaction. Using the new
log vector structure for this requires two passes - the first to
allocate the log vector structures and chain them together, and the
second to fill them out.  This log vector chain can then be passed
to the CIL for formatting, pinning and insertion into the CIL.

Formatting of the log vector chain is relatively simple - it's just
a loop over the iovecs on each log vector, but it is made slightly
more complex because we re-write the iovec after the copy to point
back at the memory buffer we just copied into.

This code also needs to pin log items. If the log item is not
already tracked in this checkpoint context, then it needs to be
pinned. Otherwise it is already pinned and we don't need to pin it
again.

The only other complexity is calculating the amount of new log space
the formatting has consumed. This needs to be accounted to the
transaction in progress, and the accounting is made more complex
becase we need also to steal space from it for log metadata in the
checkpoint transaction. Calculate all this at insert time and update
all the tickets, counters, etc correctly.

Once we've formatted all the log items in the transaction, attach
the busy extents to the checkpoint context so the busy extents live
until checkpoint completion and can be processed at that point in
time. Transactions can then be freed at this point in time.

Now we need to issue checkpoints - we are tracking the amount of log space
used by the items in the CIL, so we can trigger background checkpoints when the
space usage gets to a certain threshold. Otherwise, checkpoints need ot be
triggered when a log synchronisation point is reached - a log force event.

Because the log write code already handles chained log vectors, writing the
transaction is trivial, too. Construct a transaction header, add it
to the head of the chain and write it into the log, then issue a
commit record write. Then we can release the checkpoint log ticket
and attach the context to the log buffer so it can be called during
Io completion to complete the checkpoint.

We also need to allow for synchronising multiple in-flight
checkpoints. This is needed for two things - the first is to ensure
that checkpoint commit records appear in the log in the correct
sequence order (so they are replayed in the correct order). The
second is so that xfs_log_force_lsn() operates correctly and only
flushes and/or waits for the specific sequence it was provided with.

To do this we need a wait variable and a list tracking the
checkpoint commits in progress. We can walk this list and wait for
the checkpoints to change state or complete easily, an this provides
the necessary synchronisation for correct operation in both cases.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-24 10:38:03 -05:00
Dave Chinner
9bf729c0af xfs: add a shrinker to background inode reclaim
On low memory boxes or those with highmem, kernel can OOM before the
background reclaims inodes via xfssyncd. Add a shrinker to run inode
reclaim so that it inode reclaim is expedited when memory is low.

This is more complex than it needs to be because the VM folk don't
want a context added to the shrinker infrastructure. Hence we need
to add a global list of XFS mount structures so the shrinker can
traverse them.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-04-29 16:22:13 -05:00
Alex Elder
9b1f56d60a Merge branch 'for-2.6.34-rc1-batch2' into for-linus 2010-03-05 11:45:03 -06:00
Linus Torvalds
0a135ba14d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: add __percpu sparse annotations to what's left
  percpu: add __percpu sparse annotations to fs
  percpu: add __percpu sparse annotations to core kernel subsystems
  local_t: Remove leftover local.h
  this_cpu: Remove pageset_notifier
  this_cpu: Page allocator conversion
  percpu, x86: Generic inc / dec percpu instructions
  local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.c
  module: Use this_cpu_xx to dynamically allocate counters
  local_t: Remove cpu_local_xx macros
  percpu: refactor the code in pcpu_[de]populate_chunk()
  percpu: remove compile warnings caused by __verify_pcpu_ptr()
  percpu: make accessors check for percpu pointer in sparse
  percpu: add __percpu for sparse.
  percpu: make access macros universal
  percpu: remove per_cpu__ prefix.
2010-03-03 07:34:18 -08:00
Christoph Hellwig
d7658d487f xfs: kill xfs_lrw.h
Move the two declarations to better fitting headers now that
xfs_lrw.c is gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-03-01 16:35:44 -06:00
Tejun Heo
003cb608a2 percpu: add __percpu sparse annotations to fs
Add __percpu sparse annotations to fs.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-02-17 11:17:38 +09:00
Eric Sandeen
d5db0f97fb xfs: more reserved blocks fixups
This mangles the reserved blocks counts a little more.

1) add a helper function for the default reserved count
2) add helper functions to save/restore counts on ro/rw
3) save/restore reserved blocks on freeze/thaw
4) disallow changing reserved count while readonly

V2: changed field name to match Dave's changes

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-02-08 17:41:48 -06:00
Dave Chinner
cbe132a8bd xfs: don't hold onto reserved blocks on remount,ro
If we hold onto reserved blocks when doing a remount,ro we end
up writing the blocks used count to disk that includes the reserved
blocks. Reserved blocks are not actually used, so this results in
the values in the superblock being incorrect.

Hence if we run xfs_check or xfs_repair -n while the filesystem is
mounted remount,ro we end up with an inconsistent filesystem being
reported. Also, running xfs_copy on the remount,ro filesystem will
result in an inconsistent image being generated.

To fix this, unreserve the blocks when doing the remount,ro, and
reserved them again on remount,rw. This way a remount,ro filesystem
will appear consistent on disk to all utilities.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-26 15:08:49 +11:00
Dave Chinner
046ea75313 xfs: convert DM ops to use unsigned char names
dmops uses a signed char for it's namespace event. To be consistent
with the rest of the code, convert them to unsigned char for the
namespace string.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20 10:47:08 +11:00
Dave Chinner
0fa800fbd5 xfs: Add trace points for per-ag refcount debugging.
Uninline xfs_perag_{get,put} so that tracepoints can be inserted
into them to speed debugging of reference count problems.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15 15:34:12 -06:00
Dave Chinner
aed3bb90ab xfs: Reference count per-ag structures
Reference count the per-ag structures to ensure that we keep get/put
pairs balanced. Assert that the reference counts are zero at unmount
time to catch leaks. In future, reference counts will enable us to
safely remove perag structures by allowing us to detect when they
are no longer in use.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15 15:34:04 -06:00
Dave Chinner
1c1c6ebcf5 xfs: Replace per-ag array with a radix tree
The use of an array for the per-ag structures requires reallocation
of the array when growing the filesystem. This requires locking
access to the array to avoid use after free situations, and the
locking is difficult to get right. To avoid needing to reallocate an
array, change the per-ag structures to an allocated object per ag
and index them using a tree structure.

The AGs are always densely indexed (hence the use of an array), but
the number supported is 2^32 and lookups tend to be random and hence
indexing needs to scale. A simple choice is a radix tree - it works
well with this sort of index.  This change also removes another
large contiguous allocation from the mount/growfs path in XFS.

The growing process now needs to change to only initialise the new
AGs required for the extra space, and as such only needs to
exclusively lock the tree for inserts. The rest of the code only
needs to lock the tree while doing lookups, and hence this will
remove all the deadlocks that currently occur on the m_perag_lock as
it is now an innermost lock. The lock is also changed to a spinlock
from a read/write lock as the hold time is now extremely short.

To complete the picture, the per-ag structures will need to be
reference counted to ensure that we don't free/modify them while
they are still in use.  This will be done in subsequent patch.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15 15:33:52 -06:00
Dave Chinner
5017e97d52 xfs: rename xfs_get_perag
xfs_get_perag is really getting the perag that an inode belongs to
based on it's inode number. Convert the use of this function to just
get the perag from a provided ag number.  Use this new function to
obtain the per-ag structure when traversing the per AG inode trees
for sync and reclaim.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15 15:33:02 -06:00
Christoph Hellwig
30ac0683dd xfs: cleanup dmapi macros in the umount path
Stop the flag saving as we never mangle those in the unmount path, and
hide all the weird arguents to the dmapi code inside the
XFS_SEND_PREUNMOUNT / XFS_SEND_UNMOUNT macros.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2009-12-11 15:11:23 -06:00
Christoph Hellwig
b8f82a4a6f xfs: kill the STATIC_INLINE macro
Remove our own STATIC_INLINE macro.  For small function inside
implementation files just use STATIC and let gcc inline it, and for
those in headers do the normal static inline - they are all small
enough to be inlined for debug builds, too.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2009-12-11 15:11:22 -06:00