Commit Graph

22 Commits

Author SHA1 Message Date
David Chinner 45c3414112 [XFS] Apply transaction delta counts atomically to incore counters
With the per-cpu superblock counters, batch updates are no longer atomic
across the entire batch of changes. This is not an issue if each
individual change in the batch is applied atomically. Unfortunately, free
block count changes are not applied atomically, and they are applied in a
manner guaranteed to cause problems.

Essentially, the free block count reservation that the transaction took
initially is returned to the in core counters before a second delta takes
away what is used. because these two operations are not atomic, we can
race with another thread that can use the returned transaction reservation
before the transaction takes the space away again and we can then get
ENOSPC being reported in a spot where we don't have an ENOSPC condition,
nor should we ever see one there.

Fix it up by rolling the two deltas into the one so it can be applied
safely (i.e. atomically) to the incore counters.

SGI-PV: 964465
SGI-Modid: xfs-linux-melb:xfs-kern:28796a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-14 15:32:09 +10:00
David Chinner 210c6f1caa [XFS] Fix the transaction flags to make lazy superblock counters work.
SGI-PV: 964999
SGI-Modid: xfs-linux-melb:xfs-kern:28653a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-14 15:29:02 +10:00
David Chinner 92821e2ba4 [XFS] Lazy Superblock Counters
When we have a couple of hundred transactions on the fly at once, they all
typically modify the on disk superblock in some way.
create/unclink/mkdir/rmdir modify inode counts, allocation/freeing modify
free block counts.

When these counts are modified in a transaction, they must eventually lock
the superblock buffer and apply the mods. The buffer then remains locked
until the transaction is committed into the incore log buffer. The result
of this is that with enough transactions on the fly the incore superblock
buffer becomes a bottleneck.

The result of contention on the incore superblock buffer is that
transaction rates fall - the more pressure that is put on the superblock
buffer, the slower things go.

The key to removing the contention is to not require the superblock fields
in question to be locked. We do that by not marking the superblock dirty
in the transaction. IOWs, we modify the incore superblock but do not
modify the cached superblock buffer. In short, we do not log superblock
modifications to critical fields in the superblock on every transaction.
In fact we only do it just before we write the superblock to disk every
sync period or just before unmount.

This creates an interesting problem - if we don't log or write out the
fields in every transaction, then how do the values get recovered after a
crash? the answer is simple - we keep enough duplicate, logged information
in other structures that we can reconstruct the correct count after log
recovery has been performed.

It is the AGF and AGI structures that contain the duplicate information;
after recovery, we walk every AGI and AGF and sum their individual
counters to get the correct value, and we do a transaction into the log to
correct them. An optimisation of this is that if we have a clean unmount
record, we know the value in the superblock is correct, so we can avoid
the summation walk under normal conditions and so mount/recovery times do
not change under normal operation.

One wrinkle that was discovered during development was that the blocks
used in the freespace btrees are never accounted for in the AGF counters.
This was once a valid optimisation to make; when the filesystem is full,
the free space btrees are empty and consume no space. Hence when it
matters, the "accounting" is correct. But that means the when we do the
AGF summations, we would not have a correct count and xfs_check would
complain. Hence a new counter was added to track the number of blocks used
by the free space btrees. This is an *on-disk format change*.

As a result of this, lazy superblock counters are a mkfs option and at the
moment on linux there is no way to convert an old filesystem. This is
possible - xfs_db can be used to twiddle the right bits and then
xfs_repair will do the format conversion for you. Similarly, you can
convert backwards as well. At some point we'll add functionality to
xfs_admin to do the bit twiddling easily....

SGI-PV: 964999
SGI-Modid: xfs-linux-melb:xfs-kern:28652a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-14 15:28:50 +10:00
Eric Sandeen 1c72bf9003 [XFS] The last argument "lsn" of xfs_trans_commit() is always called with
NULL.

Patch provided by Eric Sandeen.

SGI-PV: 961693
SGI-Modid: xfs-linux-melb:xfs-kern:28199a

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-08 13:48:42 +10:00
David Chinner 20f4ebf2bf [XFS] Make growfs work for amounts greater than 2TB
The free block modification code has a 32bit interface, limiting the size
the filesystem can be grown even on 64 bit machines. On 32 bit machines,
there are other 32bit variables in transaction structures and interfaces
that need to be expanded to allow this to work.

SGI-PV: 959978
SGI-Modid: xfs-linux-melb:xfs-kern:27894a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-02-10 18:36:10 +11:00
Nathan Scott f6c2d1fa63 [XFS] Remove version 1 directory code. Never functioned on Linux, just
pure bloat.

SGI-PV: 952969
SGI-Modid: xfs-linux-melb:xfs-kern:26251a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-20 13:04:51 +10:00
Nathan Scott 34327e1384 [XFS] Cleanup a missed porting conversion, and freezing.
SGI-PV: 953338
SGI-Modid: xfs-linux-melb:xfs-kern:26109a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-09 17:11:55 +10:00
Nathan Scott 59c1b082f5 [XFS] Make the pflags test/set wrappers more legible for us mere humans.
SGI-PV: 953338
SGI-Modid: xfs-linux-melb:xfs-kern:26099a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-09 14:59:13 +10:00
Nathan Scott 7d04a335b6 [XFS] Shutdown the filesystem if all device paths have gone. Made
shutdown vop flags consistent with sync vop flags declarations too.

SGI-PV: 939911
SGI-Modid: xfs-linux-melb:xfs-kern:26096a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-09 14:58:38 +10:00
Nathan Scott c41564b5af [XFS] We really suck at spulling. Thanks to Chris Pascoe for fixing all
these typos.

SGI-PV: 904196
SGI-Modid: xfs-linux-melb:xfs-kern:25539a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-03-29 08:55:14 +10:00
Nathan Scott 2ddd5928d0 [XFS] Correct the dquot reservation component for the link transation.
SGI-PV: 904196
SGI-Modid: xfs-linux-melb:xfs-kern:25476a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-03-17 17:25:46 +11:00
Nathan Scott 8f79405527 [XFS] Reduce complexity in xfs_trans_init by pushing complex macros out
into functions and hence reduce the stack footprint there.

SGI-PV: 947312
SGI-Modid: xfs-linux-melb:xfs-kern:25360a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-03-14 13:32:41 +11:00
Nathan Scott 60a204f096 [XFS] Fix a thinko when generating a forced shutdown stack trace.
SGI-PV: 929558
SGI-Modid: xfs-linux-melb:xfs-kern:203817a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-01-11 15:37:00 +11:00
Ryan Hankins 0733af213f [XFS] Add a stack trace in the case of xfs_forced_shutdown.
SGI-PV: 929558
SGI-Modid: xfs-linux-melb:xfs-kern:203701a

Signed-off-by: Ryan Hankins <hankins@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-01-11 15:36:44 +11:00
Nathan Scott cfcbbbd089 [XFS] Remove old, broken nolog-mode code - noone plans to ever fix it.
SGI-PV: 944821
SGI-Modid: xfs-linux:xfs-kern:24213a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02 15:12:04 +11:00
Nathan Scott 7b71876980 [XFS] Update license/copyright notices to match the prefered SGI
boilerplate.

SGI-PV: 913862
SGI-Modid: xfs-linux:xfs-kern:23903a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02 14:58:39 +11:00
Nathan Scott a844f4510d [XFS] Remove xfs_macros.c, xfs_macros.h, rework headers a whole lot.
SGI-PV: 943122
SGI-Modid: xfs-linux:xfs-kern:23901a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02 14:38:42 +11:00
Christoph Hellwig f538d4da8d [XFS] write barrier support Issue all log sync operations as ordered
writes.  In addition flush the disk cache on fsync if the sync cached
operation didn't sync the log to disk (this requires some additional
bookeping in the transaction and log code). If the device doesn't claim to
support barriers, the filesystem has an extern log volume or the trial
superblock write with barriers enabled failed we disable barriers and
print a warning.  We should probably fail the mount completely, but that
could lead to nasty boot failures for the root filesystem.  Not enabled by
default yet, needs more destructive testing first.

SGI-PV: 912426
SGI-Modid: xfs-linux:xfs-kern:198723a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02 10:26:59 +11:00
Tim Shimmin 7e9c639615 [XFS] 929956 add log debugging and tracing info
SGI-PV: 931456
SGI-Modid: xfs-linux:xfs-kern:23155a

Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-09-02 16:42:05 +10:00
Christoph Hellwig ba0f32d460 [XFS] mark various symbols static Patch from Adrian Bunk
SGI-PV: 936255
SGI-Modid: xfs-linux:xfs-kern:192760a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-06-21 15:36:52 +10:00
Christoph Hellwig 4372d6e103 [XFS] Remove dead code. Patch from Adrian Bunk
SGI-PV: 936255
SGI-Modid: xfs-linux:xfs-kern:192759a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-06-21 15:36:00 +10:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00