Requested by hch, for consistency now it is exported.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Anton Blanchard <anton@samba.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 148f948b (vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode) broke
the raw driver.

We now call through generic_file_aio_write -> generic_write_sync ->
vfs_fsync_range.  vfs_fsync_range has:

        if (!fop || !fop->fsync) {
                ret = -EINVAL;
                goto out;
        }

But drivers/char/raw.c doesn't set an fsync method.

We have two options: fix it or remove the raw driver completely.  I'm
happy to do either, the fact this has been broken for so long suggests it
is rarely used.

The patch below adds an fsync method to the raw driver.  My knowledge of
the block layer is pretty sketchy so this could do with a once over.

If we instead decide to remove the raw driver, this patch might still be
useful as a backport to 2.6.33 and 2.6.32.
Signed-off-by: Anton Blanchard <anton@samba.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <jens.axboe@oracle.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Tested-by: Jeff Moyer <jmoyer@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since Valentin's email address @siemens.com is no longer valid, it's time
to change it to the one that actually works so that I don't have to
manually forward patches against mb862xx to him every time.
Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Acked-by: Valentin Sitdikov <v.sitdikov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mb862xxfb_accel built as a separate module, but it does not have a
MODULE_LICENSE, so it taints the kernel.  Add a MODULE_LICENSE to it (same
as mb862xxfb license).

mb862xxfb_accel: module license 'unspecified' taints kernel.

Or should mb862xxfb_accel be built into the mb862xxfb binary file instead?
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Alexander Shishkin <virtuoso@slind.org>
Cc: Valentin Sitdikov <v.sitdikov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Shaohua Li reported his tmpfs streaming I/O test can lead to make oom.
The test uses a 6G tmpfs in a system with 3G memory.  In the tmpfs, there
are 6 copies of kernel source and the test does kbuild for each copy.  His
investigation shows the test has a lot of rotated anon pages and quite few
file pages, so get_scan_ratio calculates percent[0] (i.e.  scanning
percent for anon) to be zero.  Actually the percent[0] shoule be a big
value, but our calculation round it to zero.

Although before commit 84b18490 ("vmscan: get_scan_ratio() cleanup") , we
have the same problem too.  But the old logic can rescue percent[0]==0
case only when priority==0.  It had hided the real issue.  I didn't think
merely streaming io can makes percent[0]==0 && priority==0 situation.  but
I was wrong.

So, definitely we have to fix such tmpfs streaming io issue.  but anyway I
revert the regression commit at first.

This reverts commit 84b18490.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I hit this when we had a bug in IDR for a few days.  Basically sysfs would
fail to create new inodes since it uses an IDR and therefore class_create
would fail.

While we are unlikely to see this fail we may as well handle it instead of
oopsing.
Signed-off-by: Anton Blanchard <anton@samba.org>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

btrfs relocate_file_extent_cluster() calls us with NULL filp:

  [ 4005.426805] BUG: unable to handle kernel NULL pointer dereference at 00000021
  [ 4005.426818] IP: [<c109a130>] page_cache_sync_readahead+0x18/0x3e
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Yan Zheng <yanzheng@21cn.com>
Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Tested-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Made necessary by 6992f533 ("sysfs: Use
one lockdep class per sysfs attribute").

Prevents further "key xxx not in .data" bug-reports.  Although some
attributes could probably be converted to static ones, this is left for
people having hardware to test.

Found by this semantic patch:

@ init @
type T;
identifier A;
@@

        T {
                ...
                struct device_attribute A;
                ...
        };

@ main extends init @
expression E;
statement S;
identifier err;
T *name;
@@

        ... when != sysfs_attr_init(&name->A.attr);
(
+       sysfs_attr_init(&name->A.attr);
        if (device_create_file(E, &name->A))
                S
|
+       sysfs_attr_init(&name->A.attr);
        err = device_create_file(E, &name->A);
)

While reviewing, I put the initialization to apropriate places.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg KH <gregkh@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Mike Isely <isely@pobox.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Initialize sysfs attributes before device_create_file call.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15548Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg KH <gregkh@suse.de>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We take the spin_lock again in fail_all_cmds() so we need to unlock here.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Steve Cameron <scameron@beardog.cce.hp.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This should be spin_lock_irq() to match the spin_unlock_irq().  Originally
it was a lock_kernel() but we switched everything to spin_lock_irq() last
November.

[akpm@linux-foundation.org: fix the MOXA_ASPP_MON case too (per Jiri)]
Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The reset of data lines when the card is removed from the cage results in
a failure.The failure is seen if the card is removed from the cage when TC
is pending after a CMD with data received CC.The reset logic leaves the
controller in a state where niether a TC is received nor DTO.

The rest code can be safely removed here since it is taken care in the IRQ
handler.
Signed-off-by: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In an error handling case the lock is not unlocked.  The return is
converted to a goto, to share the unlock at the end of the function.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E1;
identifier f;
@@

f (...) { <+...
* spin_lock_irqsave (E1,...);
... when != E1
* return ...;
...+> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: <richard.rojfors@pelagicore.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rs_init() is failing to restore interrupts on two error paths, and is
incorrectly calling tty_unregister_driver() with local interrupts
disabled.

Fix these things by disabling interrupts later, after the reauest_irq()
calls.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E1;
identifier f;
@@

f (...) { <+...
* local_irq_save (E1,...);
... when != E1
* return ...;
...+> }
// </smpl>

[akpm@linux-foundation.org: reimplement the fix]
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Rename imacfb.txt to efifb.txt since imacfb was moved to efifb,and change
imacfb to efifb.
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit c2e13037 ("platform-drivers: move
probe to .devinit.text in drivers/video") introduced a huge amount of
section mismatch warnings in vesafb code.  Rather than converting all of
the annotations, do the obvious and revert the __init -> __devinit change,
and use the recommended (in that patch) alternative to calling
platform_driver_register(): vesafb depends on information obtained from by
kernel at boot time, cannot be a module, and no post-boot devices can ever
show up.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

DECLARE_KFIFO creates a union with a struct kfifo and a buffer array with
size [size + sizeof(struct kfifo)].

INIT_KFIFO then sets the buffer pointer in struct kfifo to point to the
beginning of the buffer array which means that the first call to kfifo_in
will overwrite members of the struct kfifo.
Signed-off-by: David Härdeman <david@hardeman.nu>
Acked-by: Stefani Seibold <stefani@seibold.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

- We weren't zeroing p->rss_stat[] at fork()

- Consequently sync_mm_rss() was dereferencing tsk->mm for kernel
  threads and was oopsing.

- Make __sync_task_rss_stat() static, too.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15648

[akpm@linux-foundation.org: remove the BUG_ON(!mm->rss)]
Reported-by: Troels Liebe Bentsen <tlb@rapanden.dk>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
"Michael S. Tsirkin" <mst@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Migration has been completed so remove this now.  There's one straggler in
linux-next's drivers/mtd/sm_ftl.c.  A patch has been sent.

Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6:
  pcmcia: fix up alignf issues

Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: Force MSI irq handlers to run with interrupts disabled

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  [WATCHDOG] hpwdt - fix lower timeout limit
  [WATCHDOG] iTCO_wdt: TCO Watchdog patch for additional Intel Cougar Point DeviceIDs
  [WATCHDOG] doc: Fix use of WDIOC_SETOPTIONS ioctl.
  [WATCHDOG] doc: watchdog simple example: don't fail on fsync()
  [WATCHDOG] set max63xx driver as ARM only
  [WATCHDOG] powerpc: pika_wdt ident cannot be const

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  libata: unlock HPA if device shrunk
  libata: disable NCQ on Crucial C300 SSD
  libata: don't whine on spurious IRQ

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (37 commits)
  smc91c92_cs: fix the problem of "Unable to find hardware address"
  r8169: clean up my printk uglyness
  net: Hook up cxgb4 to Kconfig and Makefile
  cxgb4: Add main driver file and driver Makefile
  cxgb4: Add remaining driver headers and L2T management
  cxgb4: Add packet queues and packet DMA code
  cxgb4: Add HW and FW support code
  cxgb4: Add register, message, and FW definitions
  netlabel: Fix several rcu_dereference() calls used without RCU read locks
  bonding: fix potential deadlock in bond_uninit()
  net: check the length of the socket address passed to connect(2)
  stmmac: add documentation for the driver.
  stmmac: fix kconfig for crc32 build error
  be2net: fix bug in vlan rx path for big endian architecture
  be2net: fix flashing on big endian architectures
  be2net: fix a bug in flashing the redboot section
  bonding: bond_xmit_roundrobin() fix
  drivers/net: Add missing unlock
  net: gianfar - align BD ring size console messages
  net: gianfar - initialize per-queue statistics
  ...

copy_to_user() returns the number of bytes left to be copied.

This was a typo from: d82ef020 "proc: pagemap: Hold mmap_sem during
page walk".
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Some BIOSes don't configure HPA during boot but do so while resuming.
This causes harddrives to shrink during resume making libata detach
and reattach them.  This can be worked around by unlocking HPA if old
size equals native size.

Add ATA_DFLAG_UNLOCK_HPA so that HPA unlocking can be controlled
per-device and update ata_dev_revalidate() such that it sets
ATA_DFLAG_UNLOCK_HPA and fails with -EIO when the above condition is
detected.

This patch fixes the following bug.

  https://bugzilla.kernel.org/show_bug.cgi?id=15396Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Oleksandr Yermolenko <yaa.bta@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Crucial said,

  Thank you for contacting us. We know that with our M225 line of SSDs
  you sometimes need to disable NCQ (native command queuing) to avoid
  just the type of errors you're seeing. Our recommendation for the
  M225 is to add libata.force=noncq to your Linux kernel boot options,
  under the kernel ATA library option.

  I have sent your feedback to the engineers working on the C300, and
  asked them to please pass it on to the firmware team. I have been
  notified that they are in the process of testing and finalizing a
  new firmware version, that you can expect to see released around the
  end of April. We’ll keep you posted as to when it will be available
  for download.

So, turn off NCQ on the drive w/ the current firmware revision.

Reported in the following bug.

  https://bugzilla.kernel.org/show_bug.cgi?id=15573Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: lethalwp@scarlet.be
Reported-by: Luke Macken <lmacken@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

On configurations where IRQ line is shared with a different
controller, spurious IRQs may happen continuously.  The message was
put there primarily for debugging anyway.  Kill it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[Novell Bug 581103] HP Watchdog driver has arbitrary (wrong) timeout limits.
Fix the lower timeout limit to a more appropriate value.
Signed-off-by: Thomas Mingarelli <Thomas.Mingarelli@hp.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: stable <stable@kernel.org>

This patch adds the Intel Cougar Point PCH LPC Controller DeviceIDs for iTCO Watchdog.
Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: stable <stable@kernel.org>

In the watchdog-test program and watchdog-api.txt, pass the values to
the WDIOC_SETOPTIONS ioctl as a pointer to an integer containing the
values intead of directly in the third ioctl argument. The actual
watchdog drivers in drivers/watchdog don't read the options directly
from the argument but use get_user and copy_from_user.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Module refcounting is implemented with a per-cpu counter for speed.
However there is a race when tallying the counter where a reference may
be taken by one CPU and released by another.  Reference count summation
may then see the decrement without having seen the previous increment,
leading to lower than expected count.  A module which never has its
actual reference drop below 1 may return a reference count of 0 due to
this race.

Module removal generally runs under stop_machine, which prevents this
race causing bugs due to removal of in-use modules.  However there are
other real bugs in module.c code and driver code (module_refcount is
exported) where the callers do not run under stop_machine.

Fix this by maintaining running per-cpu counters for the number of
module refcount increments and the number of refcount decrements.  The
increments are tallied after the decrements, so any decrement seen will
always have its corresponding increment counted.  The final refcount is
the difference of the total increments and decrements, preventing a
low-refcount from being returned.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] qla1280: retain firmware for error recovery
  [SCSI] attirbute_container: Initialize sysfs attributes with sysfs_attr_init
  [SCSI] advansys: fix regression with request_firmware change
  [SCSI] qla2xxx: Updated version number to 8.03.02-k2.
  [SCSI] qla2xxx: Prevent sending mbx commands from sysfs during isp reset.
  [SCSI] qla2xxx: Disable MSI on qla24xx chips other than QLA2432.
  [SCSI] qla2xxx: Check to make sure multique and CPU affinity support is not enabled at the same time.
  [SCSI] qla2xxx: Correct vp_idx checking during PORT_UPDATE processing.
  [SCSI] qla2xxx: Honour "Extended BB credits" bit for CNAs.
  [SCSI] scsi_transport_fc: Make sure commands are completed when rport is offline
  [SCSI] libiscsi: Fix recovery slowdown regression

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: saving negative to unsigned char
  9p: return on mutex_lock_interruptible()
  9p: Creating files with names too long should fail with ENAMETOOLONG.
  9p: Make sure we are able to clunk the cached fid on umount
  9p: drop nlink remove
  fs/9p: Clunk the fid resulting from partial walk of the name
  9p: documentation update
  9p: Fix setting of protocol flags in v9fs_session_info structure.

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: add check for changed leaves in setup_leaf_for_split
  Btrfs: create snapshot references in same commit as snapshot
  Btrfs: fix small race with delalloc flushing waitqueue's
  Btrfs: use add_to_page_cache_lru, use __page_cache_alloc
  Btrfs: fix chunk allocate size calculation
  Btrfs: kill max_extent mount option
  Btrfs: fail to mount if we have problems reading the block groups
  Btrfs: check btrfs_get_extent return for IS_ERR()
  Btrfs: handle kmalloc() failure in inode lookup ioctl
  Btrfs: dereferencing freed memory
  Btrfs: Simplify num_stripes's calculation logical for __btrfs_alloc_chunk()
  Btrfs: Add error handle for btrfs_search_slot() in btrfs_read_chunk_tree()
  Btrfs: Remove unnecessary finish_wait() in wait_current_trans()
  Btrfs: add NULL check for do_walk_down()
  Btrfs: remove duplicate include in ioctl.c

Fix trivial conflict in fs/btrfs/compression.c due to slab.h include
cleanups.

There have been a number of reports of people seeing the message:
"name_count maxed, losing inode data: dev=00:05, inode=3185"
in dmesg.  These usually lead to people reporting problems to the filesystem
group who are in turn clueless what they mean.

Eventually someone finds me and I explain what is going on and that
these come from the audit system.  The basics of the problem is that the
audit subsystem never expects a single syscall to 'interact' (for some
wish washy meaning of interact) with more than 20 inodes.  But in fact
some operations like loading kernel modules can cause changes to lots of
inodes in debugfs.

There are a couple real fixes being bandied about including removing the
fixed compile time limit of 20 or not auditing changes in debugfs (or
both) but neither are small and obvious so I am not sending them for
immediate inclusion (I hope Al forwards a real solution next devel
window).

In the meantime this patch simply adds 'audit' to the beginning of the
crap message so if a user sees it, they come blame me first and we can
talk about what it means and make sure we understand all of the reasons
it can happen and make sure this gets solved correctly in the long run.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Saving -EINVAL as unsigned char truncates the high bits and changes it
into 234 instead of -22.  This breaks the test for "if (ret == -EINVAL)"
in parse_opts().
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

If "err" is -EINTR here the original code calls mutex_unlock() and then
returns, but it should just return directly.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

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setup_leaf_for_split needs to drop the path and search again, and has
checks to see if the item we want to split changed size.  But, it misses
the case where the leaf changed and now has enough room for the item
we want to insert.

This adds an extra check to make sure the leaf really needs splitting
before we call btrfs_split_leaf(), which keeps us from trying to split
a leaf with a single item.

btrfs_split_leaf() will blindly split the single item leaf, leaving us
with one good leaf and one empty leaf and then a crash.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

This creates the reference to a new snapshot in the same commit as the
snapshot itself.  This avoids the need for a second commit in order for a
snapshot to be persistent, and also avoids the problem of "leaking" a
new snapshot tree root if the host crashes before the second commit takes
place.

It is not at all clear to me why it wasn't always done this way.  If there
is still a reason for the two-stage {create,finish}_pending_snapshots()
approach I'm missing something!  :)

I've been running this for a couple weeks under pretty heavy usage (a few
snapshots per minute) without obvious problems.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>