Commit Graph

75729 Commits

Author SHA1 Message Date
Steven Whitehouse
ff91cc9bb4 [GFS2] Fix log block mapper
A missing offset in the calculation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:15:58 +00:00
Bob Peterson
fa3742fa85 [GFS2] Minor correction
This is a small correction to my previously posted patch1.
It just changes a divide to a shift.  It's faster and doesn't
introduce odd dependencies on 32-bit compiles.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:15:37 +00:00
Bob Peterson
c3f60b6e3a [GFS2] Eliminate the no longer needed sd_statfs_mutex
This patch eliminates the unneeded sd_statfs_mutex mutex but preserves
the ordering as discussed.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:15:16 +00:00
Bob Peterson
b3513fca7e [GFS2] Incremental patch to fix compiler warning
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:14:53 +00:00
Bob Peterson
15c7cee799 [GFS2] Function meta_read optimization
This patch optimizes function gfs2_meta_read.  Basically, gfs2_meta_wait
was being called regardless of whether a disk read was requested.
This just pulls that wait into the if that triggers the read.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:14:33 +00:00
Bob Peterson
b0d5fd3074 [GFS2] Only fetch the dinode once in block_map
Function gfs2_block_map was often looking up the disk inode twice.
This optimizes it so that only does it once.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:14:13 +00:00
Bob Peterson
398bbe6832 [GFS2] Reorganize function gfs2_glmutex_lock
This patch optimizes the function gfs2_glmutex_lock.
The basic theory is: Why bother initializing a holder, setting up
wait bits and then waiting on them, if you know the glock can be
yours.  So the holder stuff is placed inside the if checking if the
glock is locked.  This one needs careful scrutiny because changing
anything to do with locking should strike terror into one's heart.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:13:52 +00:00
Bob Peterson
5fdc2eeb5d [GFS2] Run through full bitmaps quicker in gfs2_bitfit
I eliminated the passing of an unused parameter into gfs2_bitfit called rgd.

This also changes the gfs2_bitfit code that searches for free (or used) blocks.
Before, the code was trying to check for bytes that indicated 4 blocks in
the undesired state.  The problem is, it was spending more time trying to
do this than it actually was saving.  This version only optimizes the case
where we're looking for free blocks, and it checks a machine word at a time.
So on 32-bit machines, it will check 32-bits (16 blocks) and on 64-bit
machines, it will check 64-bits (32 blocks) at a time.  The compiler
optimizes that quite well and we save some time, especially when running
through full bitmaps (like the bitmaps allocated for the journals).

There's probably a more elegant or optimized way to do this, but I haven't
thought of it yet.  I'm open to suggestions.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:13:31 +00:00
Bob Peterson
0d0868bde3 [GFS2] Get rid of useless "found" variable in quota.c
This just eliminates an unused variable from the quota code.
Not likely to be a time saver.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:13:01 +00:00
Bob Peterson
da6dd40d59 [GFS2] Journal extent mapping
This patch saves a little time when gfs2 writes to the journals by
keeping a mapping between logical and physical blocks on disk.
That's better than constantly looking up indirect pointers in
buffers, when the journals are several levels of indirection
(which they typically are).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:11:46 +00:00
Bob Peterson
e9e1ef2b6e [GFS2] Remove function gfs2_get_block
This patch is just a cleanup.  Function gfs2_get_block() just calls
function gfs2_block_map reversing the last two parameters.  By
reversing the parameters, gfs2_block_map() may be called directly
and function gfs2_get_block may be eliminated altogether.
Since this function is done for every block operation,
this streamlines the code and makes it a little bit more efficient.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:25 +00:00
David Teigland
2066b58b0a [GFS2] use pid for plock owner for nfs clients
The fl_owner is that of lockd when posix locks arrive from nfs
clients, so it can't be used to distinguish between lock holders.
Use fl_pid as owner instead; it's the pid of the process on the
nfs client.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:23 +00:00
Steven Whitehouse
dbee2199c3 [GFS2] Remove unused variable
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:20 +00:00
Abhijith Das
292c8c14ca [GFS2] patch to check for recursive lock requests in gfs2_rename code path
A certain scenario in the rename code path triggers a kernel BUG()
because it accidentally does recursive locking The first lock is
requested to unlink an already existing inode (replacing a file) and the
second lock is requested when the destination directory needs to alloc
some space. It is rare that these two
events happen during the same rename call, and even more rare that these
two instances try to lock the same rgrp. It is, however, possible.
https://bugzilla.redhat.com/show_bug.cgi?id=404711

Signed-off-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:18 +00:00
Wendy Cheng
c97bfe4351 [GFS2] Remove lock methods for lock_nolock protocol
GFS2 supports two modes of locking - lock_nolock for single node filesystem
and lock_dlm for cluster mode locking. The gfs2 lock methods are removed from
file operation table for lock_nolock protocol. This would allow VFS to handle
posix lock and flock logics just like other in-tree filesystems without
duplication.

Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:15 +00:00
Fabio M. Di Nitto
bcd405599f [GFS2] Remove unrequired code
Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:13 +00:00
Fabio Massimo Di Nitto
6a69a23f7d [GFS2] Fix build warnings
Hi Steven,

Steven Whitehouse wrote:
> Hi,
>
> Now in the -nmw git tree. Thanks,
>
> Steve.
>
> On Wed, 2007-11-21 at 11:54 -0600, Ryan O'Hara wrote:

this patch introduces a bunch of build warnings by leaving around

struct inode *inode = &ip->i_inode;

The patch in attachment cleans them up. Please apply.

Signed-off-by: Fabio Massimo Di Nitto <fabbione@ubuntu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:11 +00:00
Ryan O'Hara
002ef1dc63 [GFS2] remove unnecessary permission checks
Remove read/write permission() checks from xattr operations.
VFS layer is already handling permission for xattrs via the
xattr_permission() call, so there is no need for gfs2 to
check permissions. Futhermore, using permission() for SELinux
xattrs ops is incorrect.

Signed-off-by: Ryan O'Hara <rohara@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:08 +00:00
Fabio Massimo Di Nitto
1a2781cfa5 [GFS2] Fix runtime issue with UP kernels
The issue is indeed UP vs SMP and it is totally random.

spin_is_locked() is a bad assertion because there is no correct answer on UP.
on UP spin_is_locked() has to return either one value or another, always.

This means that in my setup I am lucky enough to trigger the issue and your you
are lucky enough not to.

the patch in attachment removes the bogus calls to BUG_ON and according to David
(in CC and thanks for the long explanation on the problem) we can rely upon
things like lockdep to find problem that might be trying to catch.

Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:06 +00:00
David Teigland
00c134756c [GFS2] tidy up error message
Print error with log_error() to be consistent with others.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:04 +00:00
Fabio Massimo Di Nitto
0b7580c786 [GFS2] Check for installation of mount helpers for DLM mounts
The patch is a fix to abort mount if the mount.gfs* and possible
umount.* are missing from /sbin.

While we do what we can to guarantee that they are installed properly in
userland (CVS HEAD), we want to make sure that mount still aborts properly.

The only sign of missing helpers is that lock_dlm will receive no mount options
at all. According to David the problem does not exist for lock_nolock as the
helpers are not required.

The patch has been tested for both gfs and gfs2 and it works as expected. The
lack of mount.gfs* will generate an error that is propagated to mount:

oot@node1:~# mount -t  gfs2 /dev/nbd2 /mnt/
mount: wrong fs type, bad option, bad superblock on /dev/nbd2,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

[ 3513.303346] GFS2: fsid=: Trying to join cluster "lock_dlm", "gutsy:gfs2"
[ 3513.304546] DLM/GFS2/GFS ERROR: (u)mount helpers are not installed properly!
[ 3513.306290] GFS2: fsid=: can't mount proto=lock_dlm, table=gutsy:gfs2, hostdata=

You might want to notice that it will also avoid mount to hang or fail silently
or with strange errors that will require the cluster to reboot/restart before
you can actually mount the filesystem again.

Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:01 +00:00
Steven Whitehouse
e35b921185 [GFS2] Don't periodically update the jindex
We only care about the content of the jindex in two cases,
one is when we mount the fs and the other is when we need
to recover another journal. In both cases we have to update
the jindex anyway, so there is no point in updating it
periodically between times, so this removes it to simplify
gfs2_logd.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:59 +00:00
Steven Whitehouse
ec69b18883 [GFS2] Move gfs2_logd into log.c
This means that we can mark gfs2_ail1_empty static and prepares
the way for further changes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:56 +00:00
Steven Whitehouse
fd041f0b40 [GFS2] Use atomic_t for journal free blocks counter
This patch changes the counter which keeps track of the free
blocks in the journal to an atomic_t in preparation for the
following patch which will update the log reservation code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:54 +00:00
Steven Whitehouse
2bcd610d2f [GFS2] Don't add glocks to the journal
The only reason for adding glocks to the journal was to keep track
of which locks required a log flush prior to release. We add a
flag to the glock to allow this check to be made in a simpler way.

This reduces the size of a glock (by 12 bytes on i386, 24 on x86_64)
and means that we can avoid extra work during the journal flush.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:52 +00:00
David Teigland
8cbc434247 [GFS2] check kthread_should_stop when waiting
Use wait_event_interruptible() in the lock_dlm thread instead
of an open coded equivalent, and include a kthread_should_stop()
check in the wait test so we don't miss a kthread_stop().

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:49 +00:00
Bob Peterson
c7227e4642 [GFS2] Given device ID rather than s_id in "id" sysfs file
This patch changes the /sys/fs/gfs2/<s_id>/id file to give the device
id "major:minor" rather than the s_id.  That enables gfs2_tool to
match devices properly (by id, not name) when locating the tuning files.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:47 +00:00
Steven Whitehouse
e589665eb9 [GFS2] Remove flags no longer required
The HIF_MUTEX and HIF_PROMOTE flags were set on the glock holders
depending upon which of the two waiters lists they were going to
be queued upon. They were then tested when the holders were taken
off the lists to ensure that the right type of holder was being
dequeued.

Since we are already using separate lists, there doesn't seem a
lot of point having these flags as well, and since setting them
and testing them is in the fast path for locking and unlocking
glock, this patch removes them.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:44 +00:00
Steven Whitehouse
3042a2ccd6 [GFS2] Reorder writeback for glock sync
Previously we were doing (write data, wait for data, write metadata, wait
for metadata). After this patch we so (write metadata, write data, wait for
data, wait for metadata) which should be more efficient.

Also I noticed that the drop_bh and xmote_bh functions were almost
identical. In fact the only difference was a single test, and that
test is such that in the drop_bh case, it would always evaluate to
the correct result. As such we can use the xmote_bh functions in
all the places where we were using the drop_bh function and remove
the drop_bh functions.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:42 +00:00
Steven Whitehouse
52d4c74b08 [GFS2] Add sync_page to metadata address space operations
This set of address space operations was missing a sync_page
operation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:40 +00:00
Steven Whitehouse
c2932e03db [GFS2] Remove "reclaim limit"
This call to reclaim glocks is not needed, and in particular we don't want it
in the fast path for locking glocks. The limit was entirely arbitrary anyway
and we can't expect users to adjust things like this, the remaining code will
do the right thing on its own.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:37 +00:00
Steven Whitehouse
60b0d08779 [GFS2] Remove unused variables
These haven't been used for some time, remove them.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:35 +00:00
Steven Whitehouse
47e83b5091 [GFS2] Use correct include file in ops_address.c
Something changed in the upstream kernel, and it needs this
one-liner to allow ops_address.c to build.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:32 +00:00
Steven Whitehouse
c41d4f09f1 [GFS2] Don't hold page lock when starting transaction
This is an addendum to the new AOPs work which moves the point
at which we take the page lock so that we don't get it until
the last possible moment. This resolves a conflict between
starting transactions and the page lock.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:30 +00:00
Steven Whitehouse
b8e7cbb65b [GFS2] Add writepages for GFS2 jdata
This patch resolves a lock ordering issue where we had been getting
a transaction lock in the wrong order with respect to the page lock.
By using writepages rather than just writepage, it is then possible
to start a transaction before locking the page, and thus matching the
locking order elsewhere in the code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:28 +00:00
Steven Whitehouse
9ff8ec32e5 [GFS2] Split gfs2_writepage into three cases
This patch splits gfs2_writepage into separate functions for each of
the three cases: writeback, ordered and journalled. As a result
it becomes a lot easier to see what each one is doing. The common
code is moved into gfs2_writepage_common.

This fixes a performance bug where we were doing more work than
strictly required in the ordered write case.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:25 +00:00
Steven Whitehouse
5561093e2c [GFS2] Introduce gfs2_set_aops()
Just like ext3 we now have three sets of address space operations
to cover the cases of writeback, ordered and journalled data
writes. This means that the individual operations can now become
less complicated as we are able to remove some of the tests for
file data mode from the code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:23 +00:00
Steven Whitehouse
bf36a71316 [GFS2] Add gfs2_is_writeback()
This adds a function "gfs2_is_writeback()" along the lines of the
existing "gfs2_is_jdata()" in order to clean up the code and make
the various tests for the inode mode more obvious. It also fixes
the PageChecked() logic where we were resetting the flag too early
in the case of an error path.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:21 +00:00
Steven Whitehouse
e7e36f1435 [GFS2] Remove unused field in struct gfs2_inode
Removes a field that is not used.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:18 +00:00
Steven Whitehouse
f91a0d3e24 [GFS2] Remove useless i_cache from inodes
The i_cache was designed to keep references to the indirect blocks
used during block mapping so that they didn't have to be looked
up continually. The idea failed because there are too many places
where the i_cache needs to be freed, and this has in the past been
the cause of many bugs.

In addition there was no performance benefit being gained since the
disk blocks in question were cached anyway. So this patch removes
it in order to simplify the code to prepare for other changes which
would otherwise have had to add further support for this feature.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:16 +00:00
Steven Whitehouse
3cc3f710ce [GFS2] Use ->page_mkwrite() for mmap()
This cleans up the mmap() code path for GFS2 by implementing the
page_mkwrite function for GFS2. We are thus able to use the
generic filemap_fault function for our ->fault() implementation.

This now means that shared writable mappings will be much more
efficiently shared across the cluster if there is a reasonable
proportion of read activity (the greater proportion, the better).

As a side effect, it also reduces the size of the code, removes
special cases from readpage and readpages, and makes the code
path easier to follow.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:13 +00:00
Steven Whitehouse
51ff87bdd9 [GFS2] Clean up internal read function
As requested by Christoph, this patch cleans up GFS2's internal
read function so that it no longer uses the do_generic_mapping_read
function. This function is obsolete and GFS2 is the last user of it.

As a side effect the internal read code gets smaller and easier
to read and gfs2_readpage is split into two. One function has the locking
and the other function has the rest of the logic.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
2008-01-25 08:07:11 +00:00
Wendy Cheng
cc7e79b168 [GFS2] Handle multiple glock demote requests
Fix a race condition where multiple glock demote requests are sent to
a node back-to-back. This patch does a check inside handle_callback()
to see whether a demote request is in progress. If true, it sets a flag
to make sure run_queue() will loop again to handle the new request,
instead of erronously setting gl_demote_state to a different state.

Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:09 +00:00
Linus Torvalds
49914084e7 Linux 2.6.24 2008-01-24 14:58:37 -08:00
Kalle Valo
feed9bab7b spi: omap2_mcspi PIO RX fix
Before transmission of the last word in PIO RX_ONLY mode rx+tx mode
is enabled:

	/* prevent last RX_ONLY read from triggering
	 * more word i/o: switch to rx+tx
	 */
	if (c == 0 && tx == NULL)
		mcspi_write_cs_reg(spi,
				OMAP2_MCSPI_CHCONF0, l);

But because c is decremented after the test, c will never be zero and
rx+tx will not be enabled. This breaks RX_ONLY mode PIO transfers.

Fix it by decrementing c in the beginning of the various I/O loops.

Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-24 14:06:44 -08:00
Linus Torvalds
dbcc2ec60f Revert "mac80211: warn when receiving frames with unaligned data"
This reverts commit 81100eb80a for the
release, to avoid the unnecessary warning noise that is only really
relevant to wireless driver developers.

The warning will probably go right back in after I cut the release, but
at least we won't unnecessarily worry users.

Acked-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-24 13:35:10 -08:00
Linus Torvalds
901720afa3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  [SPARC64]: Partially revert "Constify function pointer tables."
2008-01-24 08:12:38 -08:00
Linus Torvalds
668ebab44c Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  Revert "ACPI: Fan: Drop force_power_state acpi_device option"
  ACPI: EC: "DEBUG" needs to be defined earlier
  ACPI: EC: add leading zeros to debug messages
  ACPI: EC: fix dmesg spam regression
  ACPI: DMI blacklist to reduce console warnings on OSI(Linux) systems.
  ACPI: Add ThinkPad R61, ThinkPad T61 to OSI(Linux) white-list
  ACPI: make _OSI(Linux) console messages smarter
  ACPI: Delete Intel Customer Reference Board (CRB) from OSI(Linux) DMI list
  ACPI: on OSI(Linux), print needed DMI rather than requesting dmidecode output
  ACPI: create acpi_dmi_dump()
  DMI: create dmi_get_slot()
  DMI: move dmi_available declaration to linux/dmi.h
  ACPI: processor: Fix null pointer dereference in throttling
2008-01-24 08:09:50 -08:00
Mel Gorman
9c09a95cf4 slab: partially revert list3 changes
Partial revert the changes made by 04231b3002
to the kmem_list3 management. On a machine with a memoryless node, this
BUG_ON was triggering

	static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
	{
		struct list_head *entry;
		struct slab *slabp;
		struct kmem_list3 *l3;
		void *obj;
		int x;

		l3 = cachep->nodelists[nodeid];
		BUG_ON(!l3);

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-24 08:07:27 -08:00
Larry Woodman
c5c99429fa fix hugepages leak due to pagetable page sharing
The shared page table code for hugetlb memory on x86 and x86_64
is causing a leak.  When a user of hugepages exits using this code
the system leaks some of the hugepages.

-------------------------------------------------------
Part of /proc/meminfo just before database startup:
HugePages_Total:  5500
HugePages_Free:   5500
HugePages_Rsvd:      0
Hugepagesize:     2048 kB

Just before shutdown:
HugePages_Total:  5500
HugePages_Free:   4475
HugePages_Rsvd:      0
Hugepagesize:     2048 kB

After shutdown:
HugePages_Total:  5500
HugePages_Free:   4988
HugePages_Rsvd:
0 Hugepagesize:     2048 kB
----------------------------------------------------------

The problem occurs durring a fork, in copy_hugetlb_page_range().  It
locates the dst_pte using huge_pte_alloc().  Since huge_pte_alloc() calls
huge_pmd_share() it will share the pmd page if can, yet the main loop in
copy_hugetlb_page_range() does a get_page() on every hugepage.  This is a
violation of the shared hugepmd pagetable protocol and creates additional
referenced to the hugepages causing a leak when the unmap of the VMA
occurs.  We can skip the entire replication of the ptes when the hugepage
pagetables are shared.  The attached patch skips copying the ptes and the
get_page() calls if the hugetlbpage pagetable is shared.

[akpm@linux-foundation.org: coding-style cleanups]
Signed-off-by: Larry Woodman <lwoodman@redhat.com>
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Ken Chen <kenchen@google.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-24 08:07:27 -08:00