__blkdev_get() doesn't rescan partitions if disk->fops->open() fails,
which leads to ghost partition devices lingering after medimum removal
is known to both the kernel and userland.  The behavior also creates a
subtle inconsistency where O_NONBLOCK open, which doesn't fail even if
there's no medium, clears the ghots partitions, which is exploited to
work around the problem from userland.

Fix it by updating __blkdev_get() to issue partition rescan after
-ENOMEDIA too.

This was reported in the following bz.

 https://bugzilla.kernel.org/show_bug.cgi?id=13029

Note for stable: 2.6.38 and later only

Cc: stable@kernel.org
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NDavid Zeuthen <zeuthen@gmail.com>
Reported-by: NMartin Pitt <martin.pitt@ubuntu.com>
Reported-by: NKay Sievers <kay.sievers@vrfy.org>
Tested-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Rather than pass in some random truncated offset to the pid-related
functions, check that the offset is in range up-front.

This is just cleanup, the previous commit fixed the real problem.

Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The free space caching code was recently reworked to
cache all the pages it needed instead of using find_get_page everywhere.

One loop was missed though, so it ended up leaking pages.  This fixes
it to use our page array instead of find_get_page.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

While checking unregister_filesystem for saftey vs extra calls for
"ext4: register ext2 and ext3 alias after ext4" I realized that
the synchronize_rcu() was called on the error path but not on
the success path.

Cc: stable (2.6.38)
Signed-off-by: NMilton Miller <miltonm@bga.com>
[ This probably won't really make a difference since commit d863b50a
  ("vfs: call rcu_barrier after ->kill_sb()"), but it's the right thing
  to do.  - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Everytime we try to allocate disk space we try and see if we can pre-emptively
allocate a chunk, but in the common case we don't allocate anything, so there is
no sense in taking the chunk_mutex at all.  So instead if we are allocating a
chunk, mark it in the space_info so we don't get two people trying to allocate
at the same time.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Reviewed-by: NLiu Bo <liubo2009@cn.fujitsu.com>

A recent commit caches the extent state in end_bio_extent_readpage,
but the search it does should look for locked extents.  This
fixes things to make it more effective.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

During RCU walk in path_lookupat and path_openat, the rcu lookup
frequently failed if looking up an absolute path, because when root
directory was looked up, seq number was not properly set in nameidata.

We dropped out of RCU walk in nameidata_drop_rcu due to mismatch in
directory entry's seq number.  We reverted to slow path walk that need
to take references.

With the following patch, I saw a 50% increase in an exim mail server
benchmark throughput on a 4-socket Nehalem-EX system.
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: stable@kernel.org (v2.6.38)
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Now that we use write_inode to flush server
cache related to fid, we don't need tsyncfs either fort dotl or dotu
protocols. For dotu this helps to do a more efficient server flush.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

revalidate should return > 0 on success. Also return 0 on ENOENT
to force do_revalidate to return NULL dentry;
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

find_free_extent likes to allocate in contiguous clusters,
which makes writeback faster, especially on SSD storage.  As
the FS fragments, these clusters become harder to find and we have
to decide between allocating a new chunk to make more clusters
or giving up on the cluster to allocate from the free space
we have.

Right now it creates too many chunks, and you can end up with
a whole FS that is mostly empty metadata chunks.  This commit
changes the allocation code to be more strict and only
allocate new chunks when we've made good use of the chunks we
already have.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The case we should be verifying when updating the dentry name is that
the _parent_ inode (the directory) semaphore is held, not the semaphore
for the dentry itself.  It's the directory locking that rename and
readdir() etc all care about.

The comment just above even says so - but then the BUG_ON() still
checked the dentry inode itself.

Very few people noticed, because this helper function really isn't used
for very much, so you had to be using ncpfs to ever hit it.

I think I should just remove the BUG_ON (the function really has just
one user), but let's run with it fixed for a while before getting rid of
it entirely.
Reported-and-tested-by: NBongani Hlope <bonganih@bankservafrica.com>
Reported-and-tested-by: NBernd Feige <bernd.feige@uniklinik-freiburg.de>
Cc: Petr Vandrovec <petr@vandrovec.name>,
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On no-mmu arch, there is a memleak during shmem test.  The cause of this
memleak is ramfs_nommu_expand_for_mapping() added page refcount to 2
which makes iput() can't free that pages.

The simple test file is like this:

  int main(void)
  {
	int i;
	key_t k = ftok("/etc", 42);

	for ( i=0; i<100; ++i) {
		int id = shmget(k, 10000, 0644|IPC_CREAT);
		if (id == -1) {
			printf("shmget error\n");
		}
		if(shmctl(id, IPC_RMID, NULL ) == -1) {
			printf("shm  rm error\n");
			return -1;
		}
	}
	printf("run ok...\n");
	return 0;
  }

And the result:

  root:/> free
               total         used         free       shared      buffers
  Mem:         60320        17912        42408            0            0
  -/+ buffers:              17912        42408
  root:/> shmem
  run ok...
  root:/> free
               total         used         free       shared      buffers
  Mem:         60320        19096        41224            0            0
  -/+ buffers:              19096        41224
  root:/> shmem
  run ok...
  root:/> free
               total         used         free       shared      buffers
  Mem:         60320        20296        40024            0            0
  -/+ buffers:              20296        40024
  ...

After this patch the test result is:(no memleak anymore)

  root:/> free
               total         used         free       shared      buffers
  Mem:         60320        16668        43652            0            0
  -/+ buffers:              16668        43652
  root:/> shmem
  run ok...
  root:/> free
               total         used         free       shared      buffers
  Mem:         60320        16668        43652            0            0
  -/+ buffers:              16668        43652
Signed-off-by: NBob Liu <lliubbo@gmail.com>
Acked-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

force_o_largefile() on ia64 is defined in <asm/fcntl.h> and requires
<linux/personality.h>.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

5520e894 ("brk: fix min_brk lower bound computation for COMPAT_BRK")
tried to get the whole logic of brk randomization for legacy
(libc5-based) applications finally right.

It turns out that the way to detect whether brk has actually been
randomized in the end or not introduced by that patch still doesn't work
for those binaries, as reported by Geert:

: /sbin/init from my old m68k ramdisk exists prematurely.
:
: Before the patch:
:
: | brk(0x80005c8e)                         = 0x80006000
:
: After the patch:
:
: | brk(0x80005c8e)                         = 0x80005c8e
:
: Old libc5 considers brk() to have failed if the return value is not
: identical to the requested value.

I don't like it, but currently see no better option than a bit flag in
task_struct to catch the CONFIG_COMPAT_BRK && randomize_va_space == 2
case.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Tested-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NTimo Warns <warns@pre-sense.de>
Cc: Eugene Teo <eugeneteo@kernel.sg>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Richard Russon <rich@flatcap.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When compiling UBIFS with CONFIG_UBIFS_FS_DEBUG not set,
gcc-4.5.2 generates a slew of "warning: statement with no effect"
on references to non-void functions defined as 0.
To avoid these warnings, replace #defines with dummy inline functions.

Artem: massage the patch a bit, also remove the duplicate
       'dbg_check_lprops()' prototype.
Signed-off-by: NMaksim Rayskiy <maksim.rayskiy@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch fixes severe UBIFS bug: UBIFS oopses when we 'fsync()' an
file on R/O-mounter file-system. We (the UBIFS authors) incorrectly
thought that VFS would not propagate 'fsync()' down to the file-system
if it is read-only, but this is not the case.

It is easy to exploit this bug using the following simple perl script:

use strict;
use File::Sync qw(fsync sync);

die "File path is not specified" if not defined $ARGV[0];
my $path = $ARGV[0];

open FILE, "<", "$path" or die "Cannot open $path: $!";
fsync(\*FILE) or die "cannot fsync $path: $!";
close FILE or die "Cannot close $path: $!";

Thanks to Reuben Dowle <Reuben.Dowle@navico.com> for reporting about this
issue.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reported-by: NReuben Dowle <Reuben.Dowle@navico.com>
Cc: stable@kernel.org

Call posix_acl_valid() to check if an acl is valid or not.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>

Link count of the inode is not decreased if btrfs_set_inode_index()
fails.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Singed-off-by: NLi Zefan <lizf@cn.fujitsu.com>

btrfs_next_leaf() can return -errno, and we should propagate
it to userspace.

This also simplifies how we walk the btree path.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>

btrfs_next_leaf() can return -errno, and we should propagate
it to userspace.

This also simplifies how we walk the btree path.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>

The extent_io code can take cached pointers into the extent state trees,
and these can make lookups much faster in common operations.  The
caching only happens when specific bits are set that prevent merging
and splitting of the extent state.

A help function was added to uncache the state, and it was testing
the same set of conditionals.  This can leak in very strange corner
cases where the lock bit goes away unexpectedly.

The uncaching should be unconditional.  Once we have a ref on the
extent we should always give it up.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

nfs_scan_commit() is called with the inode->i_lock held, but it then
calls __mark_inode_dirty() while still holding the lock. This causes
a deadlock.

Push the inode->i_lock into nfs_scan_commit() so it can protect only
the parts of the code it needs to and can be dropped before the call
to __mark_inode_dirty() to avoid the deadlock.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Tested-by: NWill Simoneau <simoneau@ele.uri.edu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 93f1c20b.

It turns out that libmount misparses it because it adds a '-' character
in the uuid string, which libmount then incorrectly confuses with the
separator string (" - ") at the end of all the optional arguments.

Upstream libmount (in the util-linux tree) has been fixed, but until
that fix actually percolates up to users, we'd better not expose this
change in the kernel.

Let's revisit this later (possibly by exposing the UUID without any '-'
characters in it, avoiding the user-space bug).
Reported-by: NDave Jones <davej@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Karel Zak <kzak@redhat.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is more or less the same patch as before, but with some merge
conflicts fixed up.

If a process has a dirty page mapped into its page tables, then it has
the ability to change it while the client is trying to write the data
out to the server. If that happens after the signature has been
calculated then that signature will then be wrong, and the server will
likely reset the TCP connection.

This patch adds a page_mkwrite handler for CIFS that simply takes the
page lock. Because the page lock is held over the life of writepage and
writepages, this prevents the page from becoming writeable until
the write call has completed.

With this, we can also remove the "sign_zero_copy" module option and
always inline the pages when writing.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Warn once if default security (ntlm) requested. We will
update the default to the stronger security mechanism
(ntlmv2) in 2.6.41.  Kerberos is also stronger than
ntlm, but more servers support ntlmv2 and ntlmv2
does not require an upcall, so ntlmv2 is a better
default.
Reviewed-by: NJeff Layton <jlayton@redhat.com>
CC: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: NShirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

When the TCP_Server_Info is first allocated and connected, tcpStatus ==
CifsGood means that the NEGOTIATE_PROTOCOL request has completed and the
socket is ready for other calls. cifs_reconnect however sets tcpStatus
to CifsGood as soon as the socket is reconnected and the optional
RFC1001 session setup is done. We have no clear way to tell the
difference between these two states, and we need to know this in order
to know whether we can send an echo or not.

Resolve this by adding a new statusEnum value -- CifsNeedNegotiate. When
the socket has been connected but has not yet had a NEGOTIATE_PROTOCOL
request done, set it to this value. Once the NEGOTIATE is done,
cifs_negotiate_protocol will set tcpStatus to CifsGood.

This also fixes and cleans the logic in cifs_reconnect and
cifs_reconnect_tcon. The old code checked for specific states when what
it really wants to know is whether the state has actually changed from
CifsNeedReconnect.
Reported-and-Tested-by: NJG <jg@cms.ac>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

While testing my patchset to fix asynchronous writes, I hit a bunch
of signature problems when testing with signing on. The problem seems
to be that signature checks on receive can be running at the same
time as a process that is sending, or even that multiple receives can
be checking signatures at the same time, clobbering the same data
structures.

While we're at it, clean up the comments over cifs_calculate_signature
and add a note that the srv_mutex should be held when calling this
function.

This patch seems to fix the problems for me, but I'm not clear on
whether it's the best approach. If it is, then this should probably
go to stable too.

Cc: stable@kernel.org
Cc: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Minor revision to the original patch. Don't abuse the __le16 variable
on the stack by casting it to wchar_t and handing it off to char2uni.
Declare an actual wchar_t on the stack instead. This fixes a valid
sparse warning.

Fix the spelling of UNI_ASTERISK. Eliminate the unneeded len_remaining
variable in cifsConvertToUCS.

Also, as David Howells points out. We were better off making
cifsConvertToUCS *not* use put_unaligned_le16 since it means that we
can't optimize the mapped characters at compile time. Switch them
instead to use cpu_to_le16, and simply use put_unaligned to set them
in the string.
Reported-and-acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Thus spake David Howells:

The code that follows this:

  	remaining = total_data_size - data_in_this_rsp;
	if (remaining == 0)
		return 0;
	else if (remaining < 0) {

generates better code if you drop the 'remaining' variable and compare
the values directly.

Clean it up per his recommendation...
Reported-and-acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Commit 522440ed made cifs set backing_dev_info on the mapping attached
to new inodes. This change caused a fairly significant read performance
regression, as cifs started doing page-sized reads exclusively.

By virtue of the fact that they're allocated as part of cifs_sb_info by
kzalloc, the ra_pages on cifs BDIs get set to 0, which prevents any
readahead. This forces the normal read codepaths to use readpage instead
of readpages causing a four-fold increase in the number of read calls
with the default rsize.

Fix it by setting ra_pages in the BDI to the same value as that in the
default_backing_dev_info.

Fixes https://bugzilla.kernel.org/show_bug.cgi?id=31662

Cc: stable@kernel.org
Reported-and-Tested-by: NTill <till2.schaefer@uni-dortmund.de>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The BCC is still __le16 at this point, and in any case we need to
use the get_bcc_le macro to make sure we don't hit alignment
problems.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Currently, we skip doing the is_path_accessible check in cifs_mount if
there is no prefixpath. I have a report of at least one server however
that allows a TREE_CONNECT to a share that has a DFS referral at its
root. The reporter in this case was using a UNC that had no prefixpath,
so the is_path_accessible check was not triggered and the box later hit
a BUG() because we were chasing a DFS referral on the root dentry for
the mount.

This patch fixes this by removing the check for a zero-length
prefixpath.  That should make the is_path_accessible check be done in
this situation and should allow the client to chase the DFS referral at
mount time instead.

Cc: stable@kernel.org
Reported-and-Tested-by: NYogesh Sharma <ysharma@cymer.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

make modules C=2 M=fs/cifs CF=-D__CHECK_ENDIAN__

Found for example:

 CHECK   fs/cifs/cifssmb.c
fs/cifs/cifssmb.c:728:22: warning: incorrect type in assignment (different base types)
fs/cifs/cifssmb.c:728:22:    expected unsigned short [unsigned] [usertype] Tid
fs/cifs/cifssmb.c:728:22:    got restricted __le16 [usertype] <noident>
fs/cifs/cifssmb.c:1883:45: warning: incorrect type in assignment (different base types)
fs/cifs/cifssmb.c:1883:45:    expected long long [signed] [usertype] fl_start
fs/cifs/cifssmb.c:1883:45:    got restricted __le64 [usertype] start
fs/cifs/cifssmb.c:1884:54: warning: restricted __le64 degrades to integer
fs/cifs/cifssmb.c:1885:58: warning: restricted __le64 degrades to integer
fs/cifs/cifssmb.c:1886:43: warning: incorrect type in assignment (different base types)
fs/cifs/cifssmb.c:1886:43:    expected unsigned int [unsigned] fl_pid
fs/cifs/cifssmb.c:1886:43:    got restricted __le32 [usertype] pid

In checking new smb2 code for missing endian conversions, I noticed
some endian errors had crept in over the last few releases into the
cifs code (symlink, ntlmssp, posix lock, and also a less problematic warning
in fscache).  A followon patch will address a few smb2 endian
problems.
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Ports are __be16 not unsigned short int

Eliminates the remaining fixable endian warnings:

~/cifs-2.6$ make modules C=1 M=fs/cifs CF=-D__CHECK_ENDIAN__
  CHECK   fs/cifs/connect.c
fs/cifs/connect.c:2408:23: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2408:23:    expected unsigned short *sport
fs/cifs/connect.c:2408:23:    got restricted __be16 *<noident>
fs/cifs/connect.c:2410:23: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2410:23:    expected unsigned short *sport
fs/cifs/connect.c:2410:23:    got restricted __be16 *<noident>
fs/cifs/connect.c:2416:24: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2416:24:    expected unsigned short [unsigned] [short] <noident>
fs/cifs/connect.c:2416:24:    got restricted __be16 [usertype] <noident>
fs/cifs/connect.c:2423:24: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2423:24:    expected unsigned short [unsigned] [short] <noident>
fs/cifs/connect.c:2423:24:    got restricted __be16 [usertype] <noident>
fs/cifs/connect.c:2326:23: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2326:23:    expected unsigned short [unsigned] sport
fs/cifs/connect.c:2326:23:    got restricted __be16 [usertype] sin6_port
fs/cifs/connect.c:2330:23: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2330:23:    expected unsigned short [unsigned] sport
fs/cifs/connect.c:2330:23:    got restricted __be16 [usertype] sin_port
fs/cifs/connect.c:2394:22: warning: restricted __be16 degrades to integer
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Max share name was set to 64, and (at least for Windows)
can be 80.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

In several places the sequence (set_extent_uptodate, unlock_extent) is used.
This leads to a duplicate lookup of the extent state. This patch lets
set_extent_uptodate return a cached extent_state which can be passed to
unlock_extent_cached.
The occurences of the above sequences are updated to use the cache. Only
end_bio_extent_readpage is updated that it first gets a cached state to
pass it to the readpage_end_io_hook as the prototype requested and is later
on being used for set/unlock.
Signed-off-by: NArne Jansen <sensille@gmx.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

I've been working on making our O_DIRECT latency not suck and I noticed we were
taking the trans_mutex in btrfs_end_transaction.  So to do this we convert
num_writers and use_count to atomic_t's and just decrement them in
btrfs_end_transaction.  Instead of deleting the transaction from the trans list
in put_transaction we do that in btrfs_commit_transaction() since that's the
only time it actually needs to be removed from the list.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>