Commit graph

28 commits

Author SHA1 Message Date
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
David Chinner
511105b3d7 [XFS] Fix vmalloc leak on mount/unmount.
When setting the length of the iclogbuf to write out we should just be
changing the desired byte count rather completely reassociating the buffer
memory with the buffer. Reassociating the buffer memory changes the
apparent length of the buffer and hence when we free the buffer, we don't
free all the vmap()d space we originally allocated.

SGI-PV: 964983
SGI-Modid: xfs-linux-melb:xfs-kern:28640a

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 15:23:23 +10:00
David Chinner
3db296f341 [XFS] Fix use-after-free during log unmount.
Don't reference the log buffer after running the callbacks as the callback
can trigger the log buffers to be freed during unmount.

SGI-PV: 964545
SGI-Modid: xfs-linux-melb:xfs-kern:28567a

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 15:22:34 +10:00
Christoph Hellwig
1fa40b01ae [XFS] Only use refcounted pages for I/O
Many block drivers (aoe, iscsi) really want refcountable pages in bios,
which is what almost everyone send down. XFS unfortunately has a few
places where it sends down buffers that may come from kmalloc, which
breaks them.

Fix the places that use kmalloc()d buffers.

SGI-PV: 964546
SGI-Modid: xfs-linux-melb:xfs-kern:28562a

Signed-Off-By: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-14 15:21:14 +10:00
Tim Shimmin
955e47ad28 [XFS] Fixes the leak in reservation space because we weren't ungranting
space for the unmount record - which becomes a problem in the freeze/thaw
scenario.

SGI-PV: 942533
SGI-Modid: xfs-linux-melb:xfs-kern:26815a

Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-28 11:04:16 +10:00
Nathan Scott
efb8ad7e94 [XFS] Add a debug flag for allocations which are known to be larger than
one page.

SGI-PV: 955302
SGI-Modid: xfs-linux-melb:xfs-kern:26800a

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-28 11:03:05 +10:00
Nathan Scott
a3c6685eaa [XFS] Ensure xlog_state_do_callback does not report spurious warnings on
ramdisks.

SGI-PV: 954802
SGI-Modid: xfs-linux-melb:xfs-kern:26627a

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-28 11:02:14 +10:00
Nathan Scott
f5faad7994 [XFS] Fix remount vs no/barrier options by ensuring we clear unwanted
flags from iclog buffers before submitting them for writing.

SGI-PV: 954772
SGI-Modid: xfs-linux-melb:xfs-kern:26605a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-07-28 17:04:44 +10:00
Nathan Scott
5493a0fcba [XFS] Fixup whitespace damage in log_write, remove final warning.
SGI-PV: 904196
SGI-Modid: xfs-linux-melb:xfs-kern:26366a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-28 11:17:28 +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
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
b83bd13881 [XFS] Resolve a namespace collision on vfs/vfsops for FreeBSD porters.
SGI-PV: 9533338
SGI-Modid: xfs-linux-melb:xfs-kern:26106a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-09 16:48:30 +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
Jesper Juhl
014c2544e6 return statement cleanup - kill pointless parentheses
This patch removes pointless parentheses from return statements.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-15 02:37:08 +01:00
Tim Shimmin
1259845d3f [XFS] remove XFS_LOG_RES_DEBUG and turn on the res history all the time to
get more useful error info on space for trans items

SGI-PV: 947110
SGI-Modid: xfs-linux-melb:xfs-kern:24886a

Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-01-11 21:02:47 +11:00
Christoph Hellwig
dd954c69d1 [XFS] turn xlog helper macros into real functions
SGI-PV: 946205
SGI-Modid: xfs-linux-melb:xfs-kern:203360a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-01-11 15:34:50 +11:00
Eric Sandeen
65be605419 [XFS] remove unused "readonly" arg from xlog_find_tail and xlog_recover
SGI-PV: 946611
SGI-Modid: xfs-linux-melb:xfs-kern:203307a

Signed-off-by: Eric Sandeen <sandeen@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-01-11 15:34:19 +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
Nathan Scott
fc1f8c1ca3 [XFS] Track external log/realtime device names for correct reporting in
/proc/mounts.

SGI-PV: 942984
SGI-Modid: xfs-linux:xfs-kern:23862a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02 11:44:33 +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
Christoph Hellwig
da1650a5d6 [XFS] Add format checking to cmn_err and icmn_err
SGI-PV: 942243
SGI-Modid: xfs-linux:xfs-kern:198658a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02 10:21:35 +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
Tim Shimmin
32fb9b57ae [XFS] Fix up the calculation of the reservation overhead to hopefully
include all the components which make up the transaction in the ondisk
log. Having this incomplete has shown up as problems on IRIX when some v2
log changes went in. The symptom was the msg of "xfs_log_write:
reservation ran out. Need to up reservation" and was seen on synchronous
writes on files with lots of holes (and therefore lots of extents).

SGI-PV: 931457
SGI-Modid: xfs-linux:xfs-kern:23095a

Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-09-02 16:41:43 +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
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