Commit Graph

147819 Commits

Author SHA1 Message Date
Alan Cox
181bf1e815 parport_pc: clean up the modified while loops using for
And tidy up a few bits coding style detectors missed

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:03 -07:00
Alan Cox
3aeda9bc95 parport_pc: Coding style
Michael's patch fixed some of the coding style so the style is now
inconsistent. Sort the rest out

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:03 -07:00
Michael Buesch
73e0d48b8c parport_pc: Fix subscription bugs
This patch fixes array subscription bugs in the parport_pc driver.

drivers/parport/parport_pc.c: In function ‘parport_irq_probe’:
drivers/parport/parport_pc.c:1589: warning: array subscript is above array bounds
drivers/parport/parport_pc.c: In function ‘parport_pc_probe_port’:
drivers/parport/parport_pc.c:1579: warning: array subscript is above array bounds

The patch also fixes a few other array bugs, which the compiler was
unable to find. Coding style violations are also fixed.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:03 -07:00
Alan Cox
0b4068a128 tty: simplify buffer allocator cleanups
Having cleaned up the allocators we might as well remove the inline helpers
for some of it

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:02 -07:00
Alan Cox
c481c707fe tty: remove buffer special casing
Long long ago a 4K kmalloc allocated two pages so the tty layer used the
page allocator, except on some machines where the page size was huge. This was
removed from the core tty layer with the tty buffer re-implementation but not
from tty_audit or the n_tty ldisc.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:02 -07:00
Breno Leitao
aba6593bf7 icom: fixing a if clause spaghetti
adapter->version can only be ADAPTER_V2 or ADAPTER_V1. So,
that OR operand in the "if" clause is non-sense and can be removed.

Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:02 -07:00
Alexander Y. Fomichev
13858d3690 jsm: correctly support multiple 4/8-port boards
If there are more then one 4/8-port board jsm_uart_port_init
allocate a line numbers of the second and further boards
from range of previous one.

This patch fixed the problem.

Signed-off-by: Alexander Y. Fomichev <git.user@gmail.com>

[printks fixed to add jsm: ]

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:02 -07:00
Olivier Bornet
9bb41699ad tty: iuu_phoenix: update version number.
Signed-off-by: Olivier Bornet <Olivier.Bornet@puck.ch>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:02 -07:00
Olivier Bornet
96dab77ebf tty: iuu_phoenix: set termios.
set_termios can now be used for setting the parity and the stopbits. This is
needed to use with cards which use a different parity then the parity used at
start (even).

If the iuu_uart_baud function return an error, we will return the old_termios
instead of the new one.

Signed-off-by: Olivier Bornet <Olivier.Bornet@puck.ch>

This was then revamped to use the various helpers, not copy non-hardware
bits any to add mark/space parity and csize reporting

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:02 -07:00
Olivier Bornet
cc3447d179 tty: iuu_phoenix: Fix stopbit when uart goes on.
Signed-off-by: Olivier Bornet <Olivier.Bornet@puck.ch>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:02 -07:00
Olivier Bornet
5fcf62b0f1 tty: iuu_phoenix: fix locking.
Bring in the relevant bits of the 0.9 vendor driver.

Signed-off-by: Olivier Bornet <Olivier.Bornet@puck.ch>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:01 -07:00
Alan Cox
852e99d22f tty: bring ldisc into CodingStyle
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:01 -07:00
Alan Cox
f2c4c65c83 tty: Move ldisc_flush
We have a tty_ldisc file now so put tty_ldisc_flush in the right place

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:01 -07:00
Alan Cox
c65c9bc3ef tty: rewrite the ldisc locking
There are several pretty much unfixable races in the old ldisc code, especially
with respect to pty behaviour and also to hangup. It's easier to rewrite the
code than simply try and patch it up.

This patch
- splits the ldisc from the tty (so we will be able to refcount it more cleanly
  later)
- introduces a mutex lock for ldisc changing on an active device
- fixes the complete mess that hangup caused
- implements hopefully correct setldisc/close/hangup locking

There are still some problems around pty pairs that have always been there but
at least it is now possible to understand the code and fix further problems.

This fixes the following known bugs
- hang up can leak ldisc references
- hang up may not call open/close on ldisc in a matched way
- pty/tty pairs can deadlock during an ldisc change
- reading the ldisc proc files can cause every ldisc to be loaded

and probably a few other of the mysterious ldisc race reports.

I'm sure it also adds the odd new one.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:01 -07:00
Alan Cox
e8b70e7d3e tty: Extract various bits of ldisc code
Before trying to tackle the ldisc bugs the code needs to be a good deal
more readable, so do the simple extractions of routines first.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:01 -07:00
Alan Cox
5f0878acba tty: Fix oops when scanning the polling list for kgdb
Costantino Leandro found a bug in tty_find_polling_driver and provided a
patch that fixed the crash but not the underlying bug. This fixes the
underlying bug where the list walk corrupts the values it is using on a
match but then reuses them if the open fails.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:01 -07:00
Alan Cox
620df3c0a5 pty: Fix a comment
We fixed the globals, so now fix the comment

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:00 -07:00
Alan Cox
4b6ae89ef4 serial: update maintainers file
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:59 -07:00
Alan Cox
38db89799b tty: throttling race fix
The tty throttling code can race due to the lock drops. It takes very high
loads but this has been observed and verified by Rob Duncan.

The basic problem is that on an SMP box we can go

	CPU #1				CPU #2
	need to throttle ?
	suppose we should		buffer space cleared
					are we throttled
					yes ? - unthrottle
	call throttle method

This changeet take the termios lock to protect against this. The termios
lock isn't the initial obvious candidate but many implementations of throttle
methods already need to poke around their own termios structures (and nobody
really locks them against a racing change of flow control).

This does mean that anyone who is setting tty->low_latency = 1 and then
calling tty_flip_buffer_push from their unthrottle method is going to end up
collapsing in a pile of locks. However we've removed all the known bogus
users of low_latency = 1 and such use isn't safe anyway for other reasons so
catching it would be an improvement.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:59 -07:00
Arnd Bergmann
5b0ed5263c x86: fix ktermios-termio conversion
The legacy TCSETA{,W,F} ioctls failed to set the termio->c_line field
on x86. This adds a missing get_user.

The same ioctls also fail to report faulting user pointers, which
we keep ignoring.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:59 -07:00
Andre Przywara
70fd8fdecc 8250_pci: add the OXCB950 chip to the 8250 PCI driver.
This adds support for the following serial controller chip:
Oxford Semiconductor OXCB950 for PCI Cardbus interface
http://www.transdimension.com/products/serial/OXCB950.html

on this card:
ExSys EX-1370 1 port high-speed serial card for ExpressCard/34 slot

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:58 -07:00
Jiri Slaby
c3301a5c04 epca: fix test_bit parameters
Switch from ASYNC_* to ASYNCB_*, because test_bit expects
bit number, not mask.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:58 -07:00
Jiri Slaby
a391ad0f09 rocket: fix test_bit parameters
Switch from ASYNC_* to ASYNCB_*, because {test,set}_bit expect
bit number, not mask.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:58 -07:00
Jiri Slaby
70beaed22c serial: refactor ASYNC_ flags
Define ASYNCB_* flags which are bit numbers of the ASYNC_* flags.
This is useful for {test,set,clear}_bit.

Also convert each ASYNC_% to be (1 << ASYNCB_%) and define masks
with the macros, not constants.

Tested with:
#include "PATH_TO_KERNEL/include/linux/serial.h"
static struct {
        unsigned int new, old;
} as[] = {
        { ASYNC_HUP_NOTIFY, 0x0001 },
        { ASYNC_FOURPORT, 0x0002 },
...
	{ ASYNC_BOOT_ONLYMCA, 0x00400000 },
        { ASYNC_INTERNAL_FLAGS, 0xFFC00000 }
};
...
        for (a = 0; a < ARRAY_SIZE(as); a++)
                if (as[a].old != as[a].new)
                        printf("%.8x != %.8x\n", as[a].old, as[a].new);

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:58 -07:00
Alan Cox
6e47e069eb tty: Clean up the ACM driver to CodingStyle
Or at least most of it. There are further clean ups possible and there are
are also thing checkpatch moans about that would be silly to "fix".

Also note some FIXME points found as the cleanup was done.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:58 -07:00
Alan Cox
10077d4a66 tty: cdc_acm add krefs
Now we have a port structure begin using the fields and kref counts

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:58 -07:00
Jiri Slaby
b39933fbd3 tty: cyclades, remove unused variables
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:58 -07:00
Jiri Slaby
963118eef9 tty: cyclades, fix nports handling
Set up ports right after FW load so that we won't allocate maximal
(64) ports when we use few.

Also remove reading of nports in irq context, since we know it from
initialisation now.

This also fixes a tty ports unregistration on some fail paths and for
Ze which registered 64 and unregistered real port count.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:57 -07:00
Jiri Slaby
08a951e169 tty: cyclades, remove typedefs
They are unused anyway.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:57 -07:00
Jiri Slaby
2693f485c2 tty: cyclades, convert macros to inlines
Remove ugly macros and add inlines instead of them. This improves
readability and type checking a much.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:57 -07:00
Jiri Slaby
101b81590d tty: cyclades, cache HW version
Store HW version locally to not read it all the time in interrupts
and alike.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:57 -07:00
Jiri Slaby
97e87f8ebe tty: cyclades, plx9060 casts cleanup
Remove ugly all-over-the-code casts of ctl_addr to 9060 space.
Add an union to the cyclades_card structure, which contains
a pointer to both 9050 and 9060 spaces.

The 9050 space layout is unknown, so let it still as a void
__iomem pointer.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:57 -07:00
Paul Fulghum
5ba5a5d212 tty: synclink_gt add receive pio mode
Add receive programmed IO mode to reduce receive latency
when using low data rates. The receive FIFO trigger
level of 128 bytes used in DMA mode creates excessive latency
when operating at low data rates. PIO mode is selected when user
application requests data in blocks of less than 128 bytes.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:57 -07:00
Alan Cox
739e0285cb tty: Update cdc_acm
The CDC ACM driver uses the tty layer correctly so needs conversion. Start by
adding and initializing the port structures.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:57 -07:00
Alan Cox
335f8514f2 tty: Bring the usb tty port structure into more use
This allows us to clean stuff up, but is probably also going to cause
some app breakage with buggy apps as we now implement proper POSIX behaviour
for USB ports matching all the other ports. This does also mean other apps
that break on USB will now work properly.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:56 -07:00
Alan Cox
1ec739be75 tty: Implement a drain delay in the tty port
We need this for devices that cannot flush and wait, but which do not order
data and modem events. Without it we will hang up before all the data
clears the hardware. Needed for the USB changes.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:56 -07:00
Alan Cox
fcc8ac1825 tty: Add carrier processing on close to the tty_port core
Some drivers implement this internally, others miss it out. Push the
behaviour into the core code as that way everyone will do it consistently.

Update the dtr rts method to raise or lower depending upon flags. Having a
single method in this style fits most of the implementations more cleanly than
two funtions.

We need this in place before we tackle the USB side

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:56 -07:00
Jiri Slaby
65a29f60e1 tty: cyclades, remove spurious check in ISR
No need to check if dev_id is NULL, it never is.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:56 -07:00
Jiri Slaby
eca1b592d6 tty: cyclades, don't kill FW
Don't reset the PLX chip after FW load, which effectively kills
the FW, so that user had to boot manually.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:56 -07:00
Jiri Slaby
ace08c3c44 tty:cyclades, load firmware even on Ze
Ze needs firmware to be loaded as well as Zo. Move cyz_load_fw one
level upper to achieve that.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:56 -07:00
Chris Mason
b263c2c8bf Btrfs: fix extent_buffer leak during tree log replay
During tree log replay, we read in the tree log roots,
process them and then free them.  A recent change
takes an extra reference on the root node of the tree
when the root is read in, and stores that reference
in root->commit_root.

This reference was not being freed, leaving us with
one buffer pinned in ram for each subvol with
a tree log root after a crash.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-11 11:24:47 -04:00
Chris Mason
0b4dcea579 Btrfs: fix oops when btrfs_inherit_iflags called with a NULL dir
This happens during subvol creation.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-11 11:13:35 -04:00
Ingo Molnar
729ff5e2aa perf_counter tools: Clean up u64 usage
A build error slipped in:

 builtin-report.c: In function ‘hist_entry__fprintf’:
 builtin-report.c:711: error: format ‘%12d’ expects type ‘int’, but argument 3 has type ‘uint64_t’

Because we got a bit sloppy with those types. uint64_t really sucks,
because there's no printf format for it. So standardize on __u64
instead - for all types that go to or come from the ABI (which is __u64),
or for values that need to be large enough even on 32-bit.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-11 16:48:38 +02:00
Peter Zijlstra
df58ab24bf perf_counter: Rename perf_counter_limit sysctl
Rename perf_counter_limit to perf_counter_max_sample_rate and
prohibit creation of counters with a known higher sample
frequency.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-11 16:48:38 +02:00
Peter Zijlstra
0764771dab perf_counter: More paranoia settings
Rename the perf_counter_priv knob to perf_counter_paranoia (because
priv can be read as private, as opposed to privileged) and provide
one more level:

 0 - permissive
 1 - restrict cpu counters to privilidged contexts
 2 - restrict kernel-mode code counting and profiling

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-11 16:48:38 +02:00
Paul Mackerras
106b506c3a perf_counter: powerpc: Implement generalized cache events for POWER processors
This adds tables of event codes for the generalized cache events for
all the currently supported powerpc processors: POWER{4,5,5+,6,7} and
PPC970*, plus powerpc-specific code to use these tables when a
generalized cache event is requested.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <18992.36430.933526.742969@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-11 16:48:37 +02:00
Paul Mackerras
4da52960fd perf_counters: powerpc: Add support for POWER7 processors
This adds the back-end for the PMU on POWER7 processors.  POWER7
has 4 fully-programmable counters and two fixed-function counters
(which do respect the freeze conditions, can generate interrupts,
and are writable, unlike PMC5/6 on POWER5+/6).

Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <18992.36329.189378.17992@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-11 16:48:37 +02:00
Thomas Gleixner
9866b7e86a x86: memtest: use pointers of equal type for comparison
Commit c9690998ef (x86: memtest: remove
64-bit division) introduced following compile warning:

arch/x86/mm/memtest.c: In function 'memtest':
arch/x86/mm/memtest.c:56: warning: comparison of distinct pointer types lacks a cast
arch/x86/mm/memtest.c:58: warning: comparison of distinct pointer types lacks a cast

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-06-11 16:26:35 +02:00
Chris Mason
067c28adc5 Btrfs: fix -o nodatasum printk spelling
It was printing nodatacsum, which was not the correct option name.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-11 09:30:13 -04:00
Yan Zheng
85d4198e40 Btrfs: check duplicate backrefs for both data and metadata
lookup_inline_extent_backref only checks for duplicate backref for data
extents. It assumes backrefs for tree block never conflict.

This patch makes lookup_inline_extent_backref check for duplicate backrefs
for both data and tree block, so that we can detect potential bug earlier.
This is a safety check, strictly speaking it is not required.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-11 08:51:34 -04:00