The original code has one spin_lock 'qgroup_lock' to protect quota
configurations in memory. If we want to add a BTRFS_QGROUP_INFO_KEY,
it will be added to Btree firstly, and then update configurations in
memory,however, a race condition may happen between these operations.
For example:
	->add_qgroup_info_item()
		->add_qgroup_rb()

For the above case, del_qgroup_info_item() may happen just before
add_qgroup_rb().

What's worse, when we want to add a qgroup relation:
	->add_qgroup_relation_item()
		->add_qgroup_relations()

We don't have any checks whether 'src' and 'dst' exist before
add_qgroup_relation_item(), a race condition can also happen for
the above case.

To avoid race condition and have all the necessary checks, we introduce
a mutex lock 'qgroup_ioctl_lock', and we make all the user change operations
protected by the mutex lock.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Creating the subvolume/snapshots(including root subvolume) qgroup
auotomatically when enabling quota.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

__btrfs_unlink_inode() aborts its transaction when it sees errors after
it removes the directory item.  But it missed the case where
btrfs_del_dir_entries_in_log() returns an error.  If this happens then
the unlink appears to fail but the items have been removed without
updating the directory size.  The directory then has leaked bytes in
i_size and can never be removed.

Adding the missing transaction abort at least makes this failure
consistent with the other failure cases.

I noticed this while reading the code after someone on irc reported
having a directory with i_size but no entries.  I tested it by forcing
btrfs_del_dir_entries_in_log() to return -ENOMEM.
Signed-off-by: Zach Brown <zab@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

This:

   # mkfs.btrfs /dev/sdb{1,2} ; wipefs -a /dev/sdb1; mount /dev/sdb2 /mnt/test

would lead to a blkdev open/close mismatch when the mount fails, and
a permanently busy (opened O_EXCL) sdb2:

   # wipefs -a /dev/sdb2
   wipefs: error: /dev/sdb2: probing initialization failed: Device or resource busy

It's because btrfs_open_devices() may open some devices, fail on
the last one, and return that failure stored in "ret."   The mount
then fails, but the caller then does not clean up the open devices.

Chris assures me that:

"btrfs_open_devices just means: go off and open every bdev you can from
this uuid.  It should return success if we opened any of them at all."

So change the logic to ignore any open failures; just skip processing
of that device.  Later on it's decided whether we have enough devices
to continue.
Reported-by: Jan Safranek <jsafrane@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

It is very likely that there are several blocks in bio, it is very
inefficient if we get their csums one by one. This patch improves
this problem by getting the csums in batch.

According to the result of the following test, the execute time of
__btrfs_lookup_bio_sums() is down by ~28%(300us -> 217us).

 # dd if=<mnt>/file of=/dev/null bs=1M count=1024
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

A user sent me a btrfs-image of a file system that was panicing on mount during
the log recovery.  I had originally thought these problems were from a bug in
the free space cache code, but that was just a symptom of the problem.  The
problem is if your application does something like this

[prealloc][prealloc][prealloc]

the internal extent maps will merge those all together into one extent map, even
though on disk they are 3 separate extents.  So if you go to write into one of
these ranges the extent map will be right since we use the physical extent when
doing the write, but when we log the extents they will use the wrong sizes for
the remainder prealloc space.  If this doesn't happen to trip up the free space
cache (which it won't in a lot of cases) then you will get bogus entries in your
extent tree which will screw stuff up later.  The data and such will still work,
but everything else is broken.  This patch fixes this by not allowing extents
that are on the modified list to be merged.  This has the side effect that we
are no longer adding everything to the modified list all the time, which means
we now have to call btrfs_drop_extents every time we log an extent into the
tree.  So this allows me to drop all this speciality code I was using to get
around calling btrfs_drop_extents.  With this patch the testcase I've created no
longer creates a bogus file system after replaying the log.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

When logging changed extents I was logging ram_bytes as the current length,
which isn't correct, it's supposed to be the ram bytes of the original extent.
This is for compression where even if we split the extent we need to know the
ram bytes so when we uncompress the extent we know how big it will be.  This was
still working out right with compression for some reason but I think we were
getting lucky.  It was definitely off for prealloc which is why I noticed it,
btrfsck was complaining about it.  With this patch btrfsck no longer complains
after a log replay.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Dave was hitting a lockdep warning because we're now properly taking the ordered
operations mutex in the ordered wait stuff.  This is because some cases we will
have a trans handle when we are flushing delalloc space, but we can't wait on
ordered extents because we could potentially deadlock, so fix this by not doing
the wait if we have a trans handle.  Thanks
Reported-and-tested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

I noticed that we will add a block group to the space info before we add it to
the block group cache rb tree, so we could potentially allocate from the block
group before it's able to be searched for.  I don't think this is too much of
a problem, the race window is microscopic, but just in case move the tree
insertion to above the space info linking.  This makes it easier to adjust the
error handling as well, so we can remove a couple of BUG_ON(ret)'s and have real
error handling setup for these scenarios.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

If btrfs_find_all_roots() fails, 'roots' has been freed or 'roots'
fails to allocate. We don't need to free it outside btrfs_find_all_roots()
again.Fix it.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

The reason that BUG_ON() happens in these places is just
because of ENOMEM.

We try ro return ENOMEM rather than trigger BUG_ON(), the
caller will abort the transaction thus avoiding the kernel panic.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

A user reported a panic while running a balance.  What was happening was he was
relocating a block, which added the reference to the relocation tree.  Then
relocation would walk through the relocation tree and drop that reference and
free that block, and then it would walk down a snapshot which referenced the
same block and add another ref to the block.  The problem is this was all
happening in the same transaction, so the parent block was free'ed up when we
drop our reference which was immediately available for allocation, and then it
was used _again_ to add a reference for the same block from a different
snapshot.  This resulted in something like this in the delayed ref tree

add ref to 90234880, parent=2067398656, ref_root 1766, level 1
del ref to 90234880, parent=2067398656, ref_root 18446744073709551608, level 1
add ref to 90234880, parent=2067398656, ref_root 1767, level 1

as you can see the ref_root's don't match, because when we inc the ref we use
the header owner, which is the original tree the block belonged to, instead of
the data reloc tree.  Then when we remove the extent we use the reloc tree
objectid.  But none of this matters, since it is a shared reference which means
only the parent matters.  When the delayed ref stuff runs it adds all the
increments first, and then does all the drops, to make sure that we don't delete
the ref if we net a positive ref count.  But tree blocks aren't allowed to have
multiple refs from the same block, so this panics when it tries to add the
second ref.  We need the add and the drop to cancel each other out in memory so
we only do the final add.

So to fix this we need to adjust how the delayed refs are added to the tree.
Only the ref_root matters when it is a normal backref, and only the parent
matters when it is a shared backref.  So make our decision based on what ref
type we have.  This allows us to keep the ref_root in memory in case anybody
wants to use it for something else, and it allows the delayed refs to be merged
properly so we don't end up with this panic.

With this patch the users image no longer panics on mount, and it has a clean
fsck after a normal mount/umount cycle.  Thanks,

Cc: stable@vger.kernel.org
Reported-by: Roman Mamedov <rm@romanrm.ru>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Testing my enospc log code I managed to abort a transaction during mount, which
put me into an infinite loop.  This is because of two things, first we don't
reset trans_no_join if we abort during transaction commit, which will force
anybody trying to start a transaction to just loop endlessly waiting for it to
be set to 0.  But this is still just a symptom, the second issue is we don't set
the fs state to error during errors on mount.  This is because we don't want to
do the flip read only thing during mount, but we still really want to set the fs
state to an error to keep us from even getting to the trans_no_join check.  So
fix both of these things, make sure to reset trans_no_join if we abort during a
commit, and make sure we set the fs state to error no matter if we're mounting
or not.  This should keep us from getting into this infinite loop again.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Steps to reproduce:
	mkfs.btrfs <disk>
	mount <disk> <mnt>
	btrfs quota enable <mnt>
	btrfs sub create <mnt>/subv

	i=1
	while [ $i -le 10000 ]
	do
		dd if=/dev/zero of=<mnt>/subv/data_$i bs=1K count=1
		i=$(($i+1))
		if [ $i -eq 500 ]
		then
			btrfs quota disable $mnt
		fi
	done
	dmesg
Obviously, this warn_on() is unnecessary, and it will be easily triggered.
Just remove it.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

set_extent_bit()'s (u64 *failed_start) expects NULL not 0.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Document all current btrfs mount options.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

The subvolume ioctls block on the parent directory mutex that can be
held by other concurrent snapshot activity for a long time. Give the
user at least some chance to get out of this situation by allowing
to send a kill signal.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

The messages

  btrfs: unlinked 123 orphans
  btrfs: truncated 456 orphans

are not useful to regular users and raise questions whether there are
problems with the filesystem.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

This mount option was a workaround when subvol= assumed path relative
to the default subvolume, not the toplevel one. This was fixed long time
ago and subvolrootid has no effect.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

With more than one btrfs volume mounted, it can be very difficult to find
out which volume is hitting an error. btrfs_error() will print this, but
it is currently rigged as more of a fatal error handler, while many of
the printk()s are currently for debugging and yet-unhandled cases.

This patch just changes the functions where the device information is
already available. Some cases remain where the root or fs_info is not
passed to the function emitting the error.

This may introduce some confusion with volumes backed by multiple devices
emitting errors referring to the primary device in the set instead of the
one on which the error occurred.

Use btrfs_printk(fs_info, format, ...) rather than writing the device
string every time, and introduce macro wrappers ala XFS for brevity.
Since the function already cannot be used for continuations, print a
newline as part of the btrfs_printk() message rather than at each caller.
Signed-off-by: Simon Kirby <sim@hostway.ca>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

The Kconfig title does not make much sense after the cleanup of
CONFIG_EXPERIMENTAL option, align the wording with other filesystems.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Each time pick one dead root from the list and let the caller know if
it's needed to continue. This should improve responsiveness during
umount and balance which at some point waits for cleaning all currently
queued dead roots.

A new dead root is added to the end of the list, so the snapshots
disappear in the order of deletion.

The snapshot cleaning work is now done only from the cleaner thread and the
others wake it if needed.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Share the exactly same code of stopping workers.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We currently store the first key of the tree block inside the reference for the
tree block in the extent tree.  This takes up quite a bit of space.  Make a new
key type for metadata which holds the level as the offset and completely removes
storing the btrfs_tree_block_info inside the extent ref.  This reduces the size
from 51 bytes to 33 bytes per extent reference for each tree block.  In practice
this results in a 30-35% decrease in the size of our extent tree, which means we
COW less and can keep more of the extent tree in memory which makes our heavy
metadata operations go much faster.  This is not an automatic format change, you
must enable it at mkfs time or with btrfstune.  This patch deals with having
metadata stored as either the old format or the new format so it is easy to
convert.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

free_root_pointers() has been introduced to cleanup all of tree roots,
so just use it instead.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Argument 'root' is no more used in btrfs_csum_data().
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

The transaction abort stacktrace is printed only once per module
lifetime, but we'd like to see it each time it happens per mounted
filesystem.  Introduce a fs_state flag that records it.

Tweak the messages around abort:
* add error number to the first abort
* print the exact negative errno from btrfs_decode_error
* clean up btrfs_decode_error and callers
* no dots at the end of the messages
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We keep hitting bugs in the tree log replay because btrfs_remove_free_space
doesn't account for some corner case.  So add a bunch of tests to try and fully
test btrfs_remove_free_space since the only time it is called is during tree log
replay.  These tests all finish successfully, so as we find more of these bugs
we need to add to these tests to make sure we don't regress in fixing things.
I've hidden the tests behind a Kconfig option, but they take no time to run so
all btrfs developers should have this turned on all the time.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

btrfs_abort_devices() is no more used.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Pull ARM SoC fix from Olof Johansson:
 "A late-arriving fix for musb on OMAP4, resolving an issue where the
  musb IP won't be clocked and thus not functional.  Small in scope,
  most of the lines changed is a longish comment."

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: OMAP4: hwmod data: make 'ocp2scp_usb_phy_phy_48m" as the main clock

I think we could just move the full vm_iomap_memory() function into
util.h or similar, but I didn't get any reply from anybody actually
using nommu even to this trivial patch, so I'm not going to touch it any
more than required.

Here's the fairly minimal stub to make the nommu case at least
potentially work.  It doesn't seem like anybody cares, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull perf fix from Ingo Molnar:
 "This fix adds missing RCU read protection"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  events: Protect access via task_subsys_state_check()

Merge tag 'omap-for-v3.9-rc6/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

From Tony Lindgren:
One MUSB regression fix that I forgot to send earlier. Without
this MUSB no longer works on omap4 based devices.

* tag 'omap-for-v3.9-rc6/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: OMAP4: hwmod data: make 'ocp2scp_usb_phy_phy_48m" as the main clock
Signed-off-by: Olof Johansson <olof@lixom.net>

Pull media fixes from Mauro Carvalho Chehab:
 "Two driver fixes.

  One avoids reading any file at a system with a cx25821 board
  (fortunately, this is not a common device).  The other one prevents
  reading after a buffer with ISDB-T devices based on mb86a20s."

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] cx25821: do not expose broken video output streams
  [media] mb86a20s: Fix estimate_rate setting

Pull late parisc fixes from Helge Deller:
 "I know it's *very* late in the 3.9 release cycle, but since there
  aren't that many people testing the parisc linux kernel, a few (for
  our port) critical issues just showed up a few days back for the first
  time.

  What's in it?
   - add missing __ucmpdi2 symbol, which is required for btrfs on 32bit
     kernel.
   - change kunmap() macro to static inline function.  This fixes a
     debian/gcc-4.4 build error.
   - add locking when doing PTE updates.  This fixes random userspace
     crashes.
   - disable (optional) -mlong-calls compiler option for modules, else
     modules can't be loaded at runtime.
   - a smart patch by Will Deacon which fixes 64bit put_user() warnings
     on 32bit kernel."

* 'fixes-3.9-late' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: use spin_lock_irqsave/spin_unlock_irqrestore for PTE updates
  parisc: disable -mlong-calls compiler option for kernel modules
  parisc: uaccess: fix compiler warnings caused by __put_user casting
  parisc: Change kunmap macro to static inline function
  parisc: Provide __ucmpdi2 to resolve undefined references in 32 bit builds.