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  1. 22 3月, 2006 4 次提交
    • D
      [PATCH] hugepage: Strict page reservation for hugepage inodes · b45b5bd6
      由 David Gibson 提交于 
      These days, hugepages are demand-allocated at first fault time.  There's a
somewhat dubious (and racy) heuristic when making a new mmap() to check if
there are enough available hugepages to fully satisfy that mapping.

A particularly obvious case where the heuristic breaks down is where a
process maps its hugepages not as a single chunk, but as a bunch of
individually mmap()ed (or shmat()ed) blocks without touching and
instantiating the pages in between allocations.  In this case the size of
each block is compared against the total number of available hugepages.
It's thus easy for the process to become overcommitted, because each block
mapping will succeed, although the total number of hugepages required by
all blocks exceeds the number available.  In particular, this defeats such
a program which will detect a mapping failure and adjust its hugepage usage
downward accordingly.

The patch below addresses this problem, by strictly reserving a number of
physical hugepages for hugepage inodes which have been mapped, but not
instatiated.  MAP_SHARED mappings are thus "safe" - they will fail on
mmap(), not later with an OOM SIGKILL.  MAP_PRIVATE mappings can still
trigger an OOM.  (Actually SHARED mappings can technically still OOM, but
only if the sysadmin explicitly reduces the hugepage pool between mapping
and instantiation)

This patch appears to address the problem at hand - it allows DB2 to start
correctly, for instance, which previously suffered the failure described
above.

This patch causes no regressions on the libhugetblfs testsuite, and makes a
test (designed to catch this problem) pass which previously failed (ppc64,
POWER5).
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      b45b5bd6
    • N
      [PATCH] mm: nommu use compound pages · 84097518
      由 Nick Piggin 提交于 
      Now that compound page handling is properly fixed in the VM, move nommu
over to using compound pages rather than rolling their own refcounting.

nommu vm page refcounting is broken anyway, but there is no need to have
divergent code in the core VM now, nor when it gets fixed.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: David Howells <dhowells@redhat.com>

(Needs testing, please).
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      84097518
    • C
      [PATCH] slab: Remove SLAB_NO_REAP option · ac2b898c
      由 Christoph Lameter 提交于 
      SLAB_NO_REAP is documented as an option that will cause this slab not to be
reaped under memory pressure.  However, that is not what happens.  The only
thing that SLAB_NO_REAP controls at the moment is the reclaim of the unused
slab elements that were allocated in batch in cache_reap().  Cache_reap()
is run every few seconds independently of memory pressure.

Could we remove the whole thing?  Its only used by three slabs anyways and
I cannot find a reason for having this option.

There is an additional problem with SLAB_NO_REAP.  If set then the recovery
of objects from alien caches is switched off.  Objects not freed on the
same node where they were initially allocated will only be reused if a
certain amount of objects accumulates from one alien node (not very likely)
or if the cache is explicitly shrunk.  (Strangely __cache_shrink does not
check for SLAB_NO_REAP)

Getting rid of SLAB_NO_REAP fixes the problems with alien cache freeing.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      ac2b898c
    • L
      [PATCH] v9fs: assign dentry ops to negative dentries · 5e7a99ac
      由 Latchesar Ionkov 提交于 
      If a file is not found in v9fs_vfs_lookup, the function creates negative
dentry, but doesn't assign any dentry ops.  This leaves the negative entry
in the cache (there is no d_delete to mark it for removal).  If the file is
created outside of the mounted v9fs filesystem, the file shows up in the
directory with weird permissions.

This patch assigns the default v9fs dentry ops to the negative dentry.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      5e7a99ac
  3. 21 3月, 2006 7 次提交
  5. 17 3月, 2006 2 次提交
  7. 16 3月, 2006 2 次提交
    • A
      [PATCH] Fix ext2 readdir f_pos re-validation logic · 2d7f2ea9
      由 Al Viro 提交于 
      This fixes not one, but _two_, silly (but admittedly hard to hit) bugs
in the ext2 filesystem "readdir()" function.  It also cleans up the code
to avoid the unnecessary goto mess.

The bugs were related to re-valiating the f_pos value after somebody had
either done an "lseek()" on the directory to an invalid offset, or when
the offset had become invalid due to a file being unlinked in the
directory.  The code would not only set the f_version too eagerly, it
would also not update f_pos appropriately for when the offset fixup took
place.

When that happened, we'd occasionally subsequently fail the readdir()
even when we shouldn't (no real harm done, but an ugly printk, and
obviously you would end up not necessarily seeing all entries).

Thanks to Masoud Sharbiani <masouds@google.com> who noticed the problem
and had a test-case for it, and also fixed up a thinko in the first
version of this patch.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NMasoud Sharbiani <masouds@google.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      2d7f2ea9
    • A
      [PATCH] fs/namespace.c:dup_namespace(): fix a use after free · f13b8358
      由 Adrian Bunk 提交于 
      The Coverity checker spotted the following bug in dup_namespace():

<--  snip  -->

        if (!new_ns->root) {
                up_write(&namespace_sem);
                kfree(new_ns);
                goto out;
        }
...
out:
        return new_ns;

<--  snip  -->

Callers expect a non-NULL result to not be freed.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      f13b8358
  9. 15 3月, 2006 3 次提交
  11. 14 3月, 2006 3 次提交
    • T
      [PATCH] NLM: Ensure we do not Oops in the case of an unlock · 30f4e20a
      由 Trond Myklebust 提交于 
      In theory, NLM specs assure us that the server will only reply LCK_GRANTED or
LCK_DENIED_GRACE_PERIOD to our NLM_UNLOCK request.

In practice, we should not assume this to be the case, and the code will
currently Oops if we do.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      30f4e20a
    • T
      [PATCH] NFSv4: fix mount segfault on errors returned that are < -1000 · c12e87f4
      由 Trond Myklebust 提交于 
      It turns out that nfs4_proc_get_root() may return raw NFSv4 errors instead of
mapping them to kernel errors.  Problem spotted by Neil Horman
<nhorman@tuxdriver.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      c12e87f4
    • T
      [PATCH] NFS: Fix a potential panic in O_DIRECT · 143f412e
      由 Trond Myklebust 提交于 
      Based on an original patch by Mike O'Connor and Greg Banks of SGI.

Mike states:

A normal user can panic an NFS client and cause a local DoS with
'judicious'(?) use of O_DIRECT.  Any O_DIRECT write to an NFS file where the
user buffer starts with a valid mapped page and contains an unmapped page,
will crash in this way.  I haven't followed the code, but O_DIRECT reads with
similar user buffers will probably also crash albeit in different ways.

Details: when nfs_get_user_pages() calls get_user_pages(), it detects and
correctly handles get_user_pages() returning an error, which happens if the
first page covered by the user buffer's address range is unmapped.  However,
if the first page is mapped but some subsequent page isn't, get_user_pages()
will return a positive number which is less than the number of pages requested
(this behaviour is sort of analagous to a short write() call and appears to be
intentional).  nfs_get_user_pages() doesn't detect this and hands off the
array of pages (whose last few elements are random rubbish from the newly
allocated array memory) to it's caller, whence they go to
nfs_direct_write_seg(), which then totally ignores the nr_pages it's given,
and calculates its own idea of how many pages are in the array from the user
buffer length.  Needless to say, when it comes to transmit those uninitialised
page* pointers, we see a crash in the network stack.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      143f412e
  13. 12 3月, 2006 2 次提交
  15. 10 3月, 2006 2 次提交
  17. 09 3月, 2006 8 次提交
  19. 08 3月, 2006 1 次提交
  21. 07 3月, 2006 4 次提交
  23. 05 3月, 2006 1 次提交
    • S
      [CIFS] Always match oplock break (cache notification) to the right tcp · e77e6f3b
      由 Steve French 提交于 
      session when multiply mounted.

Fixes slow response when cifs client is mounted to shares on multiple
servers and oplock break occurs (usually due to attempt to multiply open a
file).  When treeids on mutiple mounted shares match and we find the wrong
match first, we searched for the wrong cached files to send oplock break
response for which usually meant that no matching file was found and thus
the server would have to timeout the notification.  Oplock break timeout is
about 20 seconds on some servers so this could cause significantly slower
performance on file open calls in a few cases (in particular when multiple
shares are mounted from multiple servers, tree ids match, and we have a
cached file which is later opened multiple times).  This was the most
important of the bugs that was found and fixed at Connectathon
(interoperability testing event) this week.

Acked-by:  Shaggy (shaggy@austin.ibm.com)
Signed-off-by: Steve French (sfrench@us.ibm.com)
      e77e6f3b
  25. 03 3月, 2006 1 次提交