Balance pause/resume logic got broken by 5ac00add (went in into 3.8-rc1
as part of dev-replace merge).  Offending commit took a stab at making
mutually exclusive volume operations (add_dev, rm_dev, resize, balance,
replace_dev) not block behind volume_mutex if another such operation is
in progress and instead return an error right away.  Balancing front-end
relied on the blocking behaviour, so the fix is ugly, but short of a
complete rework, it's the best we can do.
Reported-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

truncate() vs. ftruncate() differ in the VFS; truncate()
doesn't set (ATTR_CTIME | ATTR_MTIME), and it's up to the
fs to do the timestamp updates if the size changes.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>

btrfs_cont_expand() tries to free an IS_ERR em as it gets an error from
btrfs_get_extent() and breaks out of its loop.

An instance of -EEXIST was reported in the wild:

  https://bugzilla.redhat.com/show_bug.cgi?id=874407

I have no idea if that -EEXIST is surprising, or not.  Regardless, this
error handling should be cleaned up to handle other reasonable errors
(ENOMEM, EIO; whatever).

This seemed to be the only buggy freeing of the relatively rare IS_ERR
em so I opted to fix the caller rather than teach free_extent_map() to
use IS_ERR_OR_NULL().
Signed-off-by: Zach Brown <zab@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>

xfstests case 285 complains.

It it because btrfs did not try to find unwritten delalloc
bytes(only dirty pages, not yet writeback) behind prealloc
extents, it ends up finding nothing while we're with SEEK_DATA.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Lock end is inclusive.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We forgot to reset the path lock state to zero after we unlock the path block,
and this can lead to the ASSERT checker in tree unlock API.
Reported-by: Slava Barinov <rayslava@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

This'd avoid us empty looping.

Say we have only one disk and the metadata raid type will be defaultly DUP,
and we do not need to start from index=0(RAID10) and get over two empty
loops to index=2(DUP).
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Running xfstests 83 in a loop would sometimes fail the fsck.  This happens
because if we invalidate a page that already has an ordered extent setup for
it we will complete the ordered extent ourselves, assuming that the truncate
will clean everything up.  The problem with this is there is plenty of time
for the truncate to fail after we've done this work.  So to fix this we need
to add the orphan item first to make sure the cleanup gets done properly,
and then we can truncate the pagecache and all that stuff and be safe.  This
fixes the btrfsck failures I was seeing while running 83 in a loop.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We still need to say we're flushing if we're limit flushing to keep somebody
from coming in and stealing our reservation.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We forget to give up the write access after we find some device operation
is going on. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We should not resize a readonly device, fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Step to reproduce:
 # mkfs.btrfs <disk>
 # mount <disk> <mnt>
 # btrfs sub create <mnt>/subv0
 # btrfs sub snap <mnt> <mnt>/subv0/snap0
 # change <mnt>/subv0 from R/W to R/O
 # btrfs sub del <mnt>/subv0/snap0

We deleted the snapshot successfully. I think we should not be able to delete
the snapshot since the parent subvolume is R/O.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>

Qgroup id 0 is a special number, we should set the id of a qgroup to 0.
Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>

When we're deleting the device we should get it in write mode since
we're going to re-write the super block magic on that device. And it
should fail if the device is read-only.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>

We should free name_cache_entry before returning from the
error handling code.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>

This reverts commit 6a7a665d.

This was bug was fixed differently in 3.6, so this commit
isn't needed.

Conflicts:
	fs/btrfs/ctree.c
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This reverts commit 95c80bb1.

The bug addressed by this commit was fixed differently back in 3.6
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Users report a bug, the reproducer is:
$ mkfs.btrfs /dev/loop0
$ mount /dev/loop0 /mnt/btrfs/
$ mkdir /mnt/btrfs/dir
$ chattr +C /mnt/btrfs/dir/
$ dd if=/dev/zero of=/mnt/btrfs/dir/foo bs=4K count=10;
$ lsattr /mnt/btrfs/dir/foo
---------------C- /mnt/btrfs/dir/foo
$ filefrag /mnt/btrfs/dir/foo
/mnt/btrfs/dir/foo: 1 extent found    ---> an extent
$ dd if=/dev/zero of=/mnt/btrfs/dir/foo bs=4K count=1 seek=5 conv=notrunc,nocreat; sync
$ filefrag /mnt/btrfs/dir/foo
/mnt/btrfs/dir/foo: 3 extents found   ---> with nocow, btrfs breaks the extent into three parts

The new created file should not only inherit the NODATACOW flag, but also
honor NODATASUM flag, because we must do COW on a file extent with checksum.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

The handling for directory crc hash overflows was fairly obscure,
split_leaf returns EOVERFLOW when we try to extend the item and that is
supposed to bubble up to userland.  For a while it did so, but along the
way we added better handling of errors and forced the FS readonly if we
hit IO errors during the directory insertion.

Along the way, we started testing only for EEXIST and the EOVERFLOW case
was dropped.  The end result is that we may force the FS readonly if we
catch a directory hash bucket overflow.

This fixes a few problem spots.  First I add tests for EOVERFLOW in the
places where we can safely just return the error up the chain.

btrfs_rename is harder though, because it tries to insert the new
directory item only after it has already unlinked anything the rename
was going to overwrite.  Rather than adding very complex logic, I added
a helper to test for the hash overflow case early while it is still safe
to bail out.

Snapshot and subvolume creation had a similar problem, so they are using
the new helper now too.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Reported-by: Pascal Junod <pascal@junod.info>

This confuses and angers lockdep even though it's ok.  We don't really need
the lock for free space inodes since only the transaction committer will be
reserving space.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This happens because writeback_inodes_sb_nr_if_idle does down_read.  This
doesn't work for us and it has not been fixed upstream yet, so do it
ourselves and use that instead so we can stop having this stupid long
standing lockup.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

When a new file is created with btrfs_create(), the inode will initially be
created with permissions 0666 and later on in btrfs_init_acl() it will be
adapted to mask out the umask bits. The problem is that this change won't make
it into the btrfs_inode unless there's another change to the inode (e.g. writing
content changing the size or touching the file changing the mtime.)

This fix adds a call to btrfs_update_inode() to btrfs_create() to make sure that
the change will not get lost if the in-memory inode is flushed before other
changes are made to the file.
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Raid properties can be shared among raid calculation code, we can put
them into a global table to keep it simple.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This fixes a very special case that can be reproduced by just
disconnecting a disk at runtime, and without unmounting the
filesystem first, start scrub on the filesystem with the
disconnected disk. All read and write EIOs are handled
correctly, only the first superblock is an exception and gives
a BUG() in a subfunction. The BUG() is correct, it would crash
later otherwise. The subfunction must not be called for
superblocks and this is what the fix changes.
Reported-by: Joeri Vanthienen <mail@joerivanthienen.be>
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This starts a transaction and dirties the inode everytime we call it, which
is super expensive if you have a write heavy workload.  We will be updating
the inode when the IO completes and we reserve the space for the inode
update when we reserve space for the write, so there is no chance of loss of
information or enospc issues.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

I noticed while doing fsync tests that we were always dropping the path and
re-searching when we first cow the log root even though we've already gotten
the write lock on the root.  That's because we don't take into account that
there might not be a parent node, so fix the check to make sure there is
actually a parent node before we undo all of this work for nothing.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

If we are syncing over and over the overhead of doing all those maps in
fill_inode_item and log_changed_extents really starts to hurt, so use map
tokens so we can avoid all the extra mapping.  Since the token maps from our
offset to the end of the page make sure to set the first thing in the item
first so we really only do one map.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This gets called at least 4 times for every level while adding an object,
and it involves 3 kmapping calls, which on my box take about 5us a piece.
So instead use a token, which brings us down to 1 kmap call and makes this
function take 1/3 of the time per call.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Our token logic depends on token->kaddr being set, and if it is not it sets
everything properly as needed.  So instead of memsetting just set
token->kaddr to NULL.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

No reason to set the path blocking or loop through all of the pages if the
extent buffer isn't actually marked dirty.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This is a high traffic function, let's try and do as little as possible
during normal operations shall we?
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

We don't really need to copy extents from the source tree since we have all
of the information already available to us in the extent_map tree.  So
instead just write the extents straight to the log tree and don't bother to
copy the extent items from the source tree.
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

You'd think path->keep_locks would keep all the locks wouldn't you?  You'd
be wrong.  It only keeps them if the slot is pointing to the last item in
the node.  This is for use with btrfs_next_leaf, which needs this sort of
thing.  But the horrible horrible things I'm going to do to the tree log
means I really need everything held from root to leaf so I can add and
delete items in the same search.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

We are going to use EM's to log extents in the future, so we need to not
mark them as prealloc if they aren't actually prealloc extents.  Instead
mark them with FILLING so we know to ammend mod_start/mod_len and that way
we don't confuse the extent logging code.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

If we've written to a prealloc extent we need to know the original block len
for the extent.  We can't figure this out currently since ->block_len is
just set to the extent length.  So introduce ->orig_block_len so that we
know how many bytes were in the original extent for proper extent logging
that future patches will need.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

The tree logging stuff needs the csums to be on the ordered extents in order
to log them properly, so mark that we're sync and inline the csum creation
so we don't have to wait on the csumming to be done when logging extents
that are still in flight.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

We don't copy inode items anwyay, we just copy them straight into the log
from the in memory inode.  So if we know we're only logging the inode, don't
bother dropping anything, just try to insert it and either if it succeeds or
we get EEXIST we can update the inode item in the log and carry on.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Currently we copy all the file information into the log, inode item, the
refs, xattrs etc.  Except most of this doesn't change from fsync to fsync,
just the inode item changes.  So set a flag if an xattr changes or a link is
added, and otherwise only log the inode item.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Originally root_times_lock was introduced as part of send/receive
code however newly developed patch to label the subvol reused
the same lock, so renaming it for a meaningful name.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Currently udev does not know about the device being removed from the
file system. This may result in the situation where we're unable to
mount the file system by UUID or by LABEL because the by-uuid and
by-label links may still point to the device which is no longer part of
the btrfs file system and hence does not have any btrfs super block.

It can be easily reproduced by the following:

mkfs.btrfs -L bugfs /dev/loop[0-6]
mount /dev/loop0 /mnt/test
btrfs device delete /dev/loop0 /mnt/test
umount /mnt/test

mount LABEL=bugfs /mnt/test <---- this fails

then see:

ls -l /dev/disk/by-label/bugfs

which will still point to the /dev/loop0

We did not noticed this before because libblkid would send the udev
event for us when it notice that the link does not fit the reality,
however it does not do that anymore and completely relies on udev
information.

Fix this by sending the KOBJ_CHANGE event to the bdev kobject after
successful device removal.

Note that this does not affect device addition, because we will open the
device prior the addition from userspace and udev will notice that and
reread the device afterwards.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>