Commit graph

15 commits

Author SHA1 Message Date
Eric Sandeen
3a59c94c4b [XFS] Clean up function name handling in tracing code
Remove the hardcoded "fnames" for tracing, and just embed them in tracing
macros via __FUNCTION__. Kills a lot of #ifdefs too.

SGI-PV: 967353
SGI-Modid: xfs-linux-melb:xfs-kern:29099a

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-14 15:41:24 +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
Joe Perches
e7a23a9b37 [XFS] reducing the number of random number functions.
Patch provided by Joe Perches

SGI-PV: 961696
SGI-Modid: xfs-linux-melb:xfs-kern:28209a

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-08 13:49:03 +10:00
Nathan Scott
d432c80e68 [XFS] Minor code rearranging and cleanup to prevent some coverity false
positives.

SGI-PV: 955502
SGI-Modid: xfs-linux-melb:xfs-kern:26805a

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-28 11:03:44 +10:00
Christoph Hellwig
e21010053a [XFS] endianess annotation for xfs_agfl_t. Trivial, xfs_agfl_t is always
used for ondisk values.

SGI-PV: 954580
SGI-Modid: xfs-linux-melb:xfs-kern:26553a

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-28 10:56:51 +10:00
Nathan Scott
0e1edbd999 [XFS] Fix xfs_free_extent related NULL pointer dereference.
We recently fixed an out-of-space deadlock in XFS, and part of that fix
involved the addition of the XFS_ALLOC_FLAG_FREEING flag to some of the
space allocator calls to indicate they're freeing space, not allocating
it. There was a missed xfs_alloc_fix_freelist condition test that did not
correctly test "flags". The same test would also test an uninitialised
structure field (args->userdata) and depending on its value either would
or would not return early with a critical buffer pointer set to NULL.

This fixes that up, adds asserts to several places to catch future botches
of this nature, and skips sections of xfs_alloc_fix_freelist that are
irrelevent for the space-freeing case.

SGI-PV: 955303
SGI-Modid: xfs-linux-melb:xfs-kern:26743a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-08-10 14:40:41 +10:00
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
Yingping Lu
d210a28cd8 [XFS] In actual allocation of file system blocks and freeing extents, the
transaction within each such operation may involve multiple locking of AGF
buffer. While the freeing extent function has sorted the extents based on
AGF number before entering into transaction, however, when the file system
space is very limited, the allocation of space would try every AGF to get
space allocated, this could potentially cause out-of-order locking, thus
deadlock could happen. This fix mitigates the scarce space for allocation
by setting aside a few blocks without reservation, and avoid deadlock by
maintaining ascending order of AGF locking.

SGI-PV: 947395
SGI-Modid: xfs-linux-melb:xfs-kern:210801a

Signed-off-by: Yingping Lu <yingping@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-09 14:55:18 +10:00
Nathan Scott
e63a369001 [XFS] Fix a possible metadata buffer (AGFL) refcount leak when fixing an
AG freelist.

SGI-PV: 952681
SGI-Modid: xfs-linux-melb:xfs-kern:25902a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-05-08 19:51:58 +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
Christoph Hellwig
16259e7d95 [XFS] Endianess annotations for various allocator data structures
SGI-PV: 943272
SGI-Modid: xfs-linux:xfs-kern:201006a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02 15:11:25 +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
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
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