linux-toradex.git/fs, branch v2.6.38.6

fs/partitions/ldm.c: fix oops caused by corrupted partition table

2011-05-09T22:06:49+00:00

commit c340b1d640001c8c9ecff74f68fd90422ae2448a upstream.

The kernel automatically evaluates partition tables of storage devices.
The code for evaluating LDM partitions (in fs/partitions/ldm.c) contains
a bug that causes a kernel oops on certain corrupted LDM partitions.
A kernel subsystem seems to crash, because, after the oops, the kernel no
longer recognizes newly connected storage devices.

The patch validates the value of vblk_size.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Timo Warns 
Cc: Eugene Teo 
Cc: Harvey Harrison 
Cc: Richard Russon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Open with O_CREAT flag set fails to open existing files on non writable directories

2011-05-09T22:06:48+00:00

commit 1574dff8996ab1ed92c09012f8038b5566fce313 upstream.

An open on a NFS4 share using the O_CREAT flag on an existing file for
which we have permissions to open but contained in a directory with no
write permissions will fail with EACCES.

A tcpdump shows that the client had set the open mode to UNCHECKED which
indicates that the file should be created if it doesn't exist and
encountering an existing flag is not an error. Since in this case the
file exists and can be opened by the user, the NFS server is wrong in
attempting to check create permissions on the parent directory.

The patch adds a conditional statement to check for create permissions
only if the file doesn't exist.

Signed-off-by: Sachin S. Prabhu 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

UBIFS: seek journal heads to the latest bud in replay

2011-05-09T22:06:39+00:00

commit 52c6e6f990669deac3f370f1603815adb55a1dbd upstream.

This is the second fix of the following symptom:

UBIFS error (pid 34456): could not find an empty LEB

which sometimes happens after power cuts when we mount the file-system - UBIFS
refuses it with the above error message which comes from the
'ubifs_rcvry_gc_commit()' function. I can reproduce this using the integck test
with the UBIFS power cut emulation enabled.

Analysis of the problem.

Currently UBIFS replay seeks the journal heads to the last _replayed_ bud.
But the buds are replayed out-of-order, so the replay basically seeks journal
heads to the "random" bud belonging to this head, and not to the _last_ one.

The result of this is that the GC head may be seeked to a full LEB with no free
space, or very little free space. And 'ubifs_rcvry_gc_commit()' tries to find a
fully or mostly dirty LEB to match the current GC head (because we need to
garbage-collect that dirty LEB at one go, because we do not have @c->gc_lnum).
So 'ubifs_find_dirty_leb()' fails and we fall back to finding an empty LEB and
also fail. As a result - recovery fails and mounting fails.

This patch teaches the replay to initialize the GC heads exactly to the latest
buds, i.e. the buds which have the largest sequence number in corresponding
log reference nodes.

Signed-off-by: Artem Bityutskiy 
Signed-off-by: Greg Kroah-Hartman

UBIFS: do not free write-buffers when in R/O mode

2011-05-09T22:06:39+00:00

commit b50b9f408502a2ea90459ae36ba8cdc9cc005cfe upstream.

Currently UBIFS has a small optimization - it frees write-buffers when it is
re-mounted from R/W mode to R/O mode. Of course, when it is mounted R/O, it
does not allocate write-buffers as well.

This optimization is nice but it leads to subtle problems and complications
in recovery, which I can reproduce using the integck test. The symptoms are
that after a power cut the file-system cannot be mounted if we first mount
it R/O, and then re-mount R/W - 'ubifs_rcvry_gc_commit()' prints:

UBIFS error (pid 34456): could not find an empty LEB

Analysis of the  problem.

When mounting R/W, the reply process sets journal heads to buds [1], but
when mounting R/O - it does not do this, because the write-buffers are not
allocated. So 'ubifs_rcvry_gc_commit()' works completely differently for the
same file-system but for the following 2 cases:

1. mounting R/W after a power cut and recover
2. mounting R/O after a power cut, re-mounting R/W and run deferred recovery

In the former case, we have journal heads seeked to the a bud, in the latter
case, they are non-seeked (wbuf->lnum == -1). So in the latter case we do not
try to recover the GC LEB by garbage-collecting to the GC head, but we just
try to find an empty LEB, and there may be no empty LEBs, so we just fail.
On the other hand, in the former case (mount R/W), we are able to make a GC LEB
(@c->gc_lnum) by garbage-collecting.

Thus, let's remove this small nice optimization and always allocate
write-buffers. This should not make too big difference - we have only 3
of them, each of max. write unit size, which is usually 2KiB. So this is
about 6KiB of RAM for the typical case, and only when mounted R/O.

[1]: Note, currently the replay process is setting (seeking) the journal heads
to _some_ buds, not necessarily to the buds which had been the journal heads
before the power cut happened. This will be fixed separately.

Signed-off-by: Artem Bityutskiy 
Signed-off-by: Greg Kroah-Hartman

NFSv4.1: Ensure state manager thread dies on last umount

2011-05-02T16:19:46+00:00

commit 47c2199b6eb5fbe38ddb844db7cdbd914d304f9c upstream.

Currently, the state manager may continue to try recovering state forever
even after the last filesystem to reference that nfs_client has umounted.

Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

nfs: don't lose MS_SYNCHRONOUS on remount of noac mount

2011-05-02T16:19:46+00:00

commit 26c4c170731f00008f4317a2888a0a07ac99d90d upstream.

On a remount, the VFS layer will clear the MS_SYNCHRONOUS bit on the
assumption that the flags on the mount syscall will have it set if the
remounted fs is supposed to keep it.

In the case of "noac" though, MS_SYNCHRONOUS is implied. A remount of
such a mount will lose the MS_SYNCHRONOUS flag since "sync" isn't part
of the mount options.

Reported-by: Max Matveev 
Signed-off-by: Jeff Layton 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

vfs: avoid large kmalloc()s for the fdtable

2011-05-02T16:19:45+00:00

commit 6d4831c283530a5f2c6bd8172c13efa236eb149d upstream.

Azurit reports large increases in system time after 2.6.36 when running
Apache.  It was bisected down to a892e2d7dcdfa6c76e6 ("vfs: use kmalloc()
to allocate fdmem if possible").

That patch caused the vfs to use kmalloc() for very large allocations and
this is causing excessive work (and presumably excessive reclaim) within
the page allocator.

Fix it by falling back to vmalloc() earlier - when the allocation attempt
would have been considered "costly" by reclaim.

Reported-by: azurIt 
Tested-by: azurIt 
Acked-by: Changli Gao 
Cc: Americo Wang 
Cc: Jiri Slaby 
Acked-by: Eric Dumazet 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

UBIFS: fix false space checking failure

2011-05-02T16:19:42+00:00

commit 8c230d9a5b5ec7970139acb7e2d165d7a3fe9f9e upstream.

This patch fixes UBIFS mount failure when the debugging support is enabled,
we are recovering from a power cut, we were first mounter R/O and we are
re-mounting R/W. In this case we should not assume that the amount of free
space before we have re-mounted R/W and after are equivalent, because
when we have mounted R/O the file-system is in a non-committed state so
the amount of free space is slightly smaller, due to the fact that we cannot
predict the amount of free space precisely before we commit.

This patch fixes the issue by skipping the debugging check in case of
recovery. This issue was reported by Caizhiyong 
here: http://thread.gmane.org/gmane.linux.drivers.mtd/34350/focus=34387

Signed-off-by: Artem Bityutskiy 
Reported-by: Caizhiyong 
Signed-off-by: Greg Kroah-Hartman

UBIFS: fix master node recovery

2011-05-02T16:19:40+00:00

commit 6e0d9fd38b750d678bf9fd07db23582f52fafa55 upstream.

This patch fixes the following symptoms:
1. Unmount UBIFS cleanly.
2. Start mounting UBIFS R/W and have a power cut immediately
3. Start mounting UBIFS R/O, this succeeds
4. Try to re-mount UBIFS R/W - this fails immediately or later on,
   because UBIFS will write the master node to the flash area
   which has been written before.

The analysis of the problem:

1. UBIFS is unmounted cleanly, both copies of the master node are clean.
2. UBIFS is being mounter R/W, starts changing master node copy 1, and
   a power cut happens. The copy N1 becomes corrupted.
3. UBIFS is being mounted R/O. It notices the copy N1 is corrupted and
   reads copy N2. Copy N2 is clean.
4. Because of R/O mode, UBIFS cannot recover copy 1.
5. The mount code (ubifs_mount()) sees that the master node is clean,
   so it decides that no recovery is needed.
6. We are re-mounting R/W. UBIFS believes no recovery is needed and
   starts updating the master node, but copy N1 is still corrupted
   and was not recovered!

Fix this problem by marking the master node as dirty every time we
recover it and we are in R/O mode. This forces further recovery and
the UBIFS cleans-up the corruptions and recovers the copy N1 when
re-mounting R/W later.

Signed-off-by: Artem Bityutskiy 
Signed-off-by: Greg Kroah-Hartman

nfsd4: Fix filp leak

2011-05-02T16:19:34+00:00

commit a96e5b90804be8b540d30f4a1453fc87f95b3149 upstream.

23fcf2ec93fb8573a653408316af599939ff9a8e (nfsd4: fix oops on lock failure)

The above patch breaks free path for stp->st_file. If stp was inserted
into sop->so_stateids, we have to free stp->st_file refcount. Because
stp->st_file refcount itself is taken whether or not any refcounts are
taken on the stp->st_file->fi_fds[].

Signed-off-by: OGAWA Hirofumi 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman