btrfs: remove unused parameter from btrfs_header_fsid

Remove unused parameter, 'eb'. Unused since introduction in
5f39d397dfbe140a14edecd4e73c34ce23c4f9ee

Updated to be rebased against current upstream and correct diff supplied this time!

Signed-off-by: Ross Kirk <ross.kirk@gmail.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: fix BUG_ON() casued by the reserved space migration

When we did space balance and snapshot creation at the same time, we might
meet the following oops:
 kernel BUG at fs/btrfs/inode.c:3038!
 [SNIP]
 Call Trace:
 [<ffffffffa0411ec7>] btrfs_orphan_cleanup+0x293/0x407 [btrfs]
 [<ffffffffa042dc45>] btrfs_mksubvol.isra.28+0x259/0x373 [btrfs]
 [<ffffffffa042de85>] btrfs_ioctl_snap_create_transid+0x126/0x156 [btrfs]
 [<ffffffffa042dff1>] btrfs_ioctl_snap_create_v2+0xd0/0x121 [btrfs]
 [<ffffffffa0430b2c>] btrfs_ioctl+0x414/0x1854 [btrfs]
 [<ffffffff813b60b7>] ? __do_page_fault+0x305/0x379
 [<ffffffff811215a9>] vfs_ioctl+0x1d/0x39
 [<ffffffff81121d7c>] do_vfs_ioctl+0x32d/0x3e2
 [<ffffffff81057fe7>] ? finish_task_switch+0x80/0xb8
 [<ffffffff81121e88>] SyS_ioctl+0x57/0x83
 [<ffffffff813b39ff>] ? do_device_not_available+0x12/0x14
 [<ffffffff813b99c2>] system_call_fastpath+0x16/0x1b
 [SNIP]
 RIP  [<ffffffffa040da40>] btrfs_orphan_add+0xc3/0x126 [btrfs]

The reason of the problem is that the relocation root creation stole
the reserved space, which was reserved for orphan item deletion.

There are several ways to fix this problem, one is to increasing
the reserved space size of the space balace, and then we can use
that space to create the relocation tree for each fs/file trees.
But it is hard to calculate the suitable size because we doesn't
know how many fs/file trees we need relocate.

We fixed this problem by reserving the space for relocation root creation
actively since the space it need is very small (one tree block, used for
root node copy), then we use that reserved space to create the
relocation tree. If we don't reserve space for relocation tree creation,
we will use the reserved space of the balance.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: improve jitter performance of the sequential buffered write

The performance was slowed down sometimes when we ran sysbench to measure
the performance of the sequential buffered write by 2 or more threads.

It was because the write order of the test threads might be confused
by the task scheduler, and the coming write would be beyond the end of
the file, in this case, we need insert dummy file extents and create
a hole for the area we skip. But in order to avoid the ongoing ordered
extents which are in the area, we need wait for them. Unfortunately,
the current code doesn't check if there are ordered extents in the area
or not, try to find and flush the dirty pages directly, but in fact,
there is no dirty page in that area, this step of the current code is
unnecessary, and just wastes time. Sometimes, it would increase
the contention of some locks, and makes the performance slow down suddenly.

So we remove the ordered extent flush function before the check, and flush
the dirty pages and wait for the ordered extents only when we find them.

According to my test, we got 1-2 times of the performance regression when
we ran the test by 10 times before applying this patch. After applying
this patch, the regression went away.

Test Environment:
 CPU:		1CPU * 4Cores
 Memory:	6GB
 Partition:	20GB

Test Command:
 # sysbench --test=fileio --file-total-size=16G --file-test-mode=seqwr \
 > --num-threads=512 --file-block-size=16384 --max-time=60 --max-requests=0 run

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: fix memory leak of chunks' extent map

As we're hold a ref on looking up the extent map, we need to drop the ref
before returning to callers.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: remove unused max_key arg from btrfs_search_forward

It is not used for anything.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: remove unnecessary tree search when logging inode

In tree-log.c:btrfs_log_inode(), we keep calling btrfs_search_forward()
until it returns a key whose objectid is higher than our inode or until
the key's type is higher than our maximum allowed type.

At the end of the loop, we increment our mininum search key's objectid
and type regardless of our desired target objectid and maximum desired
type, which causes another loop iteration that will call again
btrfs_search_forward() just to figure out we've gone beyond our maximum
key and exit the loop. Therefore while incrementing our minimum key,
don't do it blindly and exit the loop immiediately if the next search
key's objectid or type is beyond what we seek.

Also after incrementing the type, set the key's offset to 0, which was
missing and could make us loose some of the inode's items.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: improve inode hash function/inode lookup

Currently the hash value used for adding an inode to the VFS's inode
hash table consists of the plain inode number, which is a 64 bits
integer. This results in hash table buckets (hlist_head lists) with
too many elements for at least 2 important scenarios:

1) When we have many subvolumes. Each subvolume has its own btree
   where its files and directories are added to, and each has its
   own objectid (inode number) namespace. This means that if we have
   N subvolumes, and all have inode number X associated to a file or
   directory, the corresponding inodes all map to the same hash table
   entry, resulting in a bucket (hlist_head list) with N elements;

2) On 32 bits machines. Th VFS hash values are unsigned longs, which
   are 32 bits wide on 32 bits machines, and the inode (objectid)
   numbers are 64 bits unsigned integers. We simply cast the inode
   numbers to hash values, which means that for all inodes with the
   same 32 bits lower half, the same hash bucket is used for all of
   them. For example, all inodes with a number (objectid) between
   0x0000_0000_ffff_ffff and 0xffff_ffff_ffff_ffff will end up in
   the same hash table bucket.

This change ensures the inode's hash value depends both on the
objectid (inode number) and its subvolume's (btree root) objectid.
For 32 bits machines, this change gives better entropy by making
the hash value depend on both the upper and lower 32 bits of the
64 bits hash previously computed.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: fix the dev-replace suspend sequence

Replace progresses strictly from lower to higher offsets, and the
progress is tracked in chunks, by storing the physical offset of the
dev_extent which is being copied in the cursor_left field of
btrfs_dev_replace_item.  When we are done copying the chunk,
left_cursor is updated to point one byte past the dev_extent, so that
on resume we can skip the dev_extents that have already been copied.

There is a major bug (which goes all the way back to the inception of
dev-replace in 3.8) in the way left_cursor is bumped: the bump is done
unconditionally, without any regard to the scrub_chunk return value.
On suspend (and also on any kind of error) scrub_chunk returns early,
i.e. without completing the copy.  This leads to us skipping the chunk
that hasn't been fully copied yet when resuming.

Fix this by doing the cursor_left update only if scrub_chunk ret is 0.
(On suspend scrub_chunk returns with -ECANCELED, so this fix covers
both suspend and error cases.)

Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: fix memory leaks on transaction commit failure

Structures of the types tree_mod_elem and qgroup_update are allocated
during transaction commit but were not being released if the call to
btrfs_run_delayed_items() returned an error.

Stack trace reported by kmemleak:

unreferenced object 0xffff880679f0b398 (size 128):
  comm "umount", pid 21508, jiffies 4295967793 (age 36718.112s)
  hex dump (first 32 bytes):
    60 b5 f0 79 06 88 ff ff 00 00 00 00 00 00 00 00  `..y............
    00 00 00 00 00 00 00 00 50 1c 00 00 00 00 00 00  ........P.......
  backtrace:
    [<ffffffff81742d26>] kmemleak_alloc+0x26/0x50
    [<ffffffff811889c2>] kmem_cache_alloc_trace+0x112/0x200
    [<ffffffffa046f2d3>] tree_mod_log_insert_key.constprop.45+0x93/0x150 [btrfs]
    [<ffffffffa04720f9>] __btrfs_cow_block+0x299/0x4f0 [btrfs]
    [<ffffffffa0472510>] btrfs_cow_block+0x120/0x1f0 [btrfs]
    [<ffffffffa0476679>] btrfs_search_slot+0x449/0x930 [btrfs]
    [<ffffffffa048eecf>] btrfs_lookup_inode+0x2f/0xa0 [btrfs]
    [<ffffffffa04eb49c>] __btrfs_update_delayed_inode+0x1c/0x1d0 [btrfs]
    [<ffffffffa04eb9e2>] __btrfs_run_delayed_items+0x162/0x1e0 [btrfs]
    [<ffffffffa04eba63>] btrfs_delayed_inode_exit+0x3/0x20 [btrfs]
    [<ffffffffa0499c63>] btrfs_commit_transaction+0x203/0xa50 [btrfs]
    [<ffffffffa046b519>] btrfs_sync_fs+0x69/0x110 [btrfs]
    [<ffffffff811cb210>] __sync_filesystem+0x30/0x60
    [<ffffffff811cb2bb>] sync_filesystem+0x4b/0x70
    [<ffffffff8119ce7b>] generic_shutdown_super+0x3b/0xf0
    [<ffffffff8119cfc6>] kill_anon_super+0x16/0x30
unreferenced object 0xffff880677e0dd88 (size 32):
  comm "umount", pid 21508, jiffies 4295967793 (age 36718.112s)
  hex dump (first 32 bytes):
    78 75 11 a9 06 88 ff ff 00 c0 e0 77 06 88 ff ff  xu.........w....
    40 c3 a2 70 06 88 ff ff 00 00 00 00 00 00 00 00  @..p............
  backtrace:
    [<ffffffff81742d26>] kmemleak_alloc+0x26/0x50
    [<ffffffff811889c2>] kmem_cache_alloc_trace+0x112/0x200
    [<ffffffffa04fa54f>] btrfs_qgroup_record_ref+0xf/0x90 [btrfs]
    [<ffffffffa04e1914>] btrfs_add_delayed_tree_ref+0xf4/0x170 [btrfs]
    [<ffffffffa048518a>] btrfs_free_tree_block+0x9a/0x220 [btrfs]
    [<ffffffffa0472163>] __btrfs_cow_block+0x303/0x4f0 [btrfs]
    [<ffffffffa0472510>] btrfs_cow_block+0x120/0x1f0 [btrfs]
    [<ffffffffa0476679>] btrfs_search_slot+0x449/0x930 [btrfs]
    [<ffffffffa048eecf>] btrfs_lookup_inode+0x2f/0xa0 [btrfs]
    [<ffffffffa04eb49c>] __btrfs_update_delayed_inode+0x1c/0x1d0 [btrfs]
    [<ffffffffa04eb9e2>] __btrfs_run_delayed_items+0x162/0x1e0 [btrfs]
    [<ffffffffa04eba63>] btrfs_delayed_inode_exit+0x3/0x20 [btrfs]
    [<ffffffffa0499c63>] btrfs_commit_transaction+0x203/0xa50 [btrfs]
    [<ffffffffa046b519>] btrfs_sync_fs+0x69/0x110 [btrfs]
    [<ffffffff811cb210>] __sync_filesystem+0x30/0x60
    [<ffffffff811cb2bb>] sync_filesystem+0x4b/0x70

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: do not free the dirty bytes from the trans block rsv on cleanup

The transactions should be cleaning up their reservations on failure, this just
causes us to have warnings on unmount because we go negative by free'ing
reservations that have already been free'ed.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: cleanup reserved space when freeing tree log on error

On error we will wait and free the tree log at unmount without a transaction.
This means that the actual freeing of the blocks doesn't happen which means we
complain about space leaks on unmount.  So to fix this just skip the transaction
specific cleanup part of the tree log free'ing if we don't have a transaction
and that way we can free up our reserved space and our counters stay happy.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: free up block groups after everything

If we abort a transaction we will do the tree log cleanup at unmount, but this
happens after we free up the block groups.  This makes all the leak detection
warnings go off because we think we've leaked space but in reality we just
haven't cleaned it up yet.  So instead do the block group cleanup stuff after
free'ing the fs roots so we don't get these warnings.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: fixup reserved trace points

In trying to track down where we were leaking reserved space I noticed our
reserve extent tracepoints are a little off.  First we were saying that the
reserved space had been alloced in btrfs_reserve_extent, which isn't the case,
this needs to be triggered when we actually allocate the space when we run the
delayed ref.  We were also missing a few places where we should have been
tracing the btrfs_reserve_extent_free tracepoint.  With these in place I was
able to put together where we were leaking reserved space.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: free reserved space on error in a few places

While trying to track down a reserved space leak I noticed a few places where we
won't properly clean up reserved space if we have an error, this patch fixes
those up.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: add tests for find_lock_delalloc_range

So both Liu and I made huge messes of find_lock_delalloc_range trying to fix
stuff, me first by fixing extent size, then him by fixing something I broke and
then me again telling him to fix it a different way.  So this is obviously a
candidate for some testing.  This patch adds a pseudo fs so we can allocate fake
inodes for tests that need an inode or pages.  Then it addes a bunch of tests to
make sure find_lock_delalloc_range is acting the way it is supposed to.  With
this patch and all of our previous patches to find_lock_delalloc_range I am sure
it is working as expected now.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: add tests for btrfs_get_extent

I'm going to be removing hole extents in the near future so I wanted to make a
sanity test for btrfs_get_extent to make sure I don't break anything in the
meantime.  This patch just puts btrfs_get_extent through its paces by giving it
a completely unreasonable mapping to look at and make sure it is giving us back
maps that make sense.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: stop all workers after we free block groups

Stefan was hitting a panic in the async worker stuff because we had outstanding
read bios while we were stopping the worker threads.  You could reproduce this
easily if you mount -o nospace_cache and ran generic/273.  This is because the
caching thread stuff is still going and we were stopping all the worker threads.
We need to stop the workers after this work is done, and the free block groups
code will wait for all the caching threads to stop first so we don't run into
this problem.  With this patch we no longer panic.  Thanks,

Cc: stable@vger.kernel.org
Reported-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: handle a missing extent for the first file extent

While trying to kill our hole extents I noticed I was seeing problems where we
seek into a file and then start writing and then try to fiemap that file later.
This is because we search for offset 0, don't find anything and so back up one
slot, which puts us at the inode ref or something like that, which means we goto
not_found and create an extent map for our entire search area.  This isn't quite
what we want, we want to move forward one slot and see if there is an extent
there so we can limit our hole extent.  This patch fixes this problem, I will
add a testcase for this as well.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: add a sanity test for a vacant extent at the front of a file

Btrfs_get_extent was not handling this case properly, add a test to make sure we
don't regress.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: fix hole check in log_one_extent

I added an assert to make sure we were looking up aligned offsets for csums and
I tripped it when running xfstests.  This is because log_one_extent was checking
if block_start == 0 for a hole instead of EXTENT_MAP_HOLE.  This worked out fine
in practice it seems, but it adds a lot of extra work that is uneeded.  With
this fix I'm no longer tripping my assert.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>