Using {} as initializer for struct seq_elem does not properly initialize
the list_head member, but it currently works because it gets set through
btrfs_get_tree_mod_seq if 'seq' is 0.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

A simple wrapper around btrfs_find_item.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

It's only a simple wrapper around btrfs_find_item, the locally defined
key is not used.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

If we are using skinny metadata, the block's tree level is in the offset
of the key and not in a btrfs_tree_block_info structure following the
extent item (it doesn't exist). Therefore fix it.

Besides returning the correct level in the tree, this also prevents reading
past the leaf's end in the case where the extent item is the last item in
the leaf (eb) and it has only 1 inline reference - this is because
sizeof(struct btrfs_tree_block_info) is greater than
sizeof(struct btrfs_extent_inline_ref).

Got it while running a scrub which produced the following warning:

    BTRFS: checksum error at logical 42123264 on dev /dev/sde, sector 15840: metadata node (level 24) in tree 5
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NSatoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

We know the tree block size, no need to pass it around.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

We have been iterating all references for each extent we have in a file when we
do fiemap to see if it is shared.  This is fine when you have a few clones or a
few snapshots, but when you have 5k snapshots suddenly fiemap just sits there
and stares at you.  So add btrfs_check_shared which will use the backref walking
code but will short circuit as soon as it finds a root or inode that doesn't
match the one we currently have.  This makes fiemap on my testbox go from
looking at me blankly for a day to spitting out actual output in a reasonable
amount of time.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

The nodesize and leafsize were never of different values. Unify the
usage and make nodesize the one. Cleanup the redundant checks and
helpers.

Shaves a few bytes from .text:

  text    data     bss     dec     hex filename
852418   24560   23112  900090   dbbfa btrfs.ko.before
851074   24584   23112  898770   db6d2 btrfs.ko.after
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

btrfs_set_key_type and btrfs_key_type are used inconsistently along with
open coded variants. Other members of btrfs_key are accessed directly
without any helpers anyway.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

We've got bug reports that btrfs crashes when quota is enabled on
32bit kernel, typically with the Oops like below:
 BUG: unable to handle kernel NULL pointer dereference at 00000004
 IP: [<f9234590>] find_parent_nodes+0x360/0x1380 [btrfs]
 *pde = 00000000
 Oops: 0000 [#1] SMP
 CPU: 0 PID: 151 Comm: kworker/u8:2 Tainted: G S      W 3.15.2-1.gd43d97e-default #1
 Workqueue: btrfs-qgroup-rescan normal_work_helper [btrfs]
 task: f1478130 ti: f147c000 task.ti: f147c000
 EIP: 0060:[<f9234590>] EFLAGS: 00010213 CPU: 0
 EIP is at find_parent_nodes+0x360/0x1380 [btrfs]
 EAX: f147dda8 EBX: f147ddb0 ECX: 00000011 EDX: 00000000
 ESI: 00000000 EDI: f147dda4 EBP: f147ddf8 ESP: f147dd38
  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
 CR0: 8005003b CR2: 00000004 CR3: 00bf3000 CR4: 00000690
 Stack:
  00000000 00000000 f147dda4 00000050 00000001 00000000 00000001 00000050
  00000001 00000000 d3059000 00000001 00000022 000000a8 00000000 00000000
  00000000 000000a1 00000000 00000000 00000001 00000000 00000000 11800000
 Call Trace:
  [<f923564d>] __btrfs_find_all_roots+0x9d/0xf0 [btrfs]
  [<f9237bb1>] btrfs_qgroup_rescan_worker+0x401/0x760 [btrfs]
  [<f9206148>] normal_work_helper+0xc8/0x270 [btrfs]
  [<c025e38b>] process_one_work+0x11b/0x390
  [<c025eea1>] worker_thread+0x101/0x340
  [<c026432b>] kthread+0x9b/0xb0
  [<c0712a71>] ret_from_kernel_thread+0x21/0x30
  [<c0264290>] kthread_create_on_node+0x110/0x110

This indicates a NULL corruption in prefs_delayed list.  The further
investigation and bisection pointed that the call of ulist_add_merge()
results in the corruption.

ulist_add_merge() takes u64 as aux and writes a 64bit value into
old_aux.  The callers of this function in backref.c, however, pass a
pointer of a pointer to old_aux.  That is, the function overwrites
64bit value on 32bit pointer.  This caused a NULL in the adjacent
variable, in this case, prefs_delayed.

Here is a quick attempt to band-aid over this: a new function,
ulist_add_merge_ptr() is introduced to pass/store properly a pointer
value instead of u64.  There are still ugly void ** cast remaining
in the callers because void ** cannot be taken implicitly.  But, it's
safer than explicit cast to u64, anyway.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=887046
Cc: <stable@vger.kernel.org> [v3.11+]
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NChris Mason <clm@fb.com>

Before processing the extent buffer, acquire a read lock on it, so
that we're safe against concurrent updates on the extent buffer.
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NChris Mason <clm@fb.com>

The skinny extents are intepreted incorrectly in scrub_print_warning(),
and end up hitting the BUG() in btrfs_extent_inline_ref_size.
Reported-by: NKonstantinos Skarlatos <k.skarlatos@gmail.com>
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <clm@fb.com>

We want to make sure the point is still within the extent item, not to verify
the memory it's pointing to.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <clm@fb.com>

The backref code was looking at nodes as well as leaves when we tried to
populate extent item entries.  This is not good, and although we go away with it
for the most part because we'd skip where disk_bytenr != random_memory,
sometimes random_memory would match and suddenly boom.  This fixes that problem.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

This exercises the various parts of the new qgroup accounting code.  We do some
basic stuff and do some things with the shared refs to make sure all that code
works.  I had to add a bunch of infrastructure because I needed to be able to
insert items into a fake tree without having to do all the hard work myself,
hopefully this will be usefull in the future.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

Lets try this again.  We can deadlock the box if we send on a box and try to
write onto the same fs with the app that is trying to listen to the send pipe.
This is because the writer could get stuck waiting for a transaction commit
which is being blocked by the send.  So fix this by making sure looking at the
commit roots is always going to be consistent.  We do this by keeping track of
which roots need to have their commit roots swapped during commit, and then
taking the commit_root_sem and swapping them all at once.  Then make sure we
take a read lock on the commit_root_sem in cases where we search the commit root
to make sure we're always looking at a consistent view of the commit roots.
Previously we had problems with this because we would swap a fs tree commit root
and then swap the extent tree commit root independently which would cause the
backref walking code to screw up sometimes.  With this patch we no longer
deadlock and pass all the weird send/receive corner cases.  Thanks,
Reportedy-by: NHugo Mills <hugo@carfax.org.uk>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

I added an optimization for large files where we would stop searching for
backrefs once we had looked at the number of references we currently had for
this extent.  This works great most of the time, but for snapshots that point to
this extent and has changes in the original root this assumption falls on it
face.  So keep track of any delayed ref mods made and add in the actual ref
count as reported by the extent item and use that to limit how far down an inode
we'll search for extents.  Thanks,
Reportedy-by: NHugo Mills <hugo@carfax.org.uk>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Reported-by: NHugo Mills <hugo@carfax.org.uk>
Tested-by: NHugo Mills <hugo@carfax.org.uk>
Signed-off-by: NChris Mason <clm@fb.com>

We won't change commit root, skip locking dance with commit root
when walking backrefs, this can speed up btrfs send operations.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

Since we have introduced btrfs_previous_extent_item() to search previous
extent item, just switch into it.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: NFilipe Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

find_all_leafs() dosen't need add all roots actually, add roots only
if we need, this can avoid unnecessary ulist dance.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

When walking backrefs, we may iterate every inode's extent
and add/merge them into ulist, and the caller will free memory
from ulist.

However, if we fail to allocate inode's extents element
memory or ulist_add() fail to allocate memory, we won't
add allocated memory into ulist, and the caller won't
free some allocated memory thus memory leaks happen.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

I can easily trigger the following warnings when enabling quota
in my virtual machine(running Opensuse), Steps are firstly creating
a subvolume full of fragment extents, and then create many snapshots
(500 in my test case).

[ 2362.808459] BUG: soft lockup - CPU#0 stuck for 22s! [btrfs-qgroup-re:1970]

[ 2362.809023] task: e4af8450 ti: e371c000 task.ti: e371c000
[ 2362.809026] EIP: 0060:[<fa38f4ae>] EFLAGS: 00000246 CPU: 0
[ 2362.809049] EIP is at __merge_refs+0x5e/0x100 [btrfs]
[ 2362.809051] EAX: 00000000 EBX: cfadbcf0 ECX: 00000000 EDX: cfadbcb0
[ 2362.809052] ESI: dd8d3370 EDI: e371dde0 EBP: e371dd6c ESP: e371dd5c
[ 2362.809054]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 2362.809055] CR0: 80050033 CR2: ac454d50 CR3: 009a9000 CR4: 001407d0
[ 2362.809099] Stack:
[ 2362.809100]  00000001 e371dde0 dfcc6890 f29f8000 e371de28 fa39016d 00000011 00000001
[ 2362.809105]  99bfc000 00000000 93928000 00000000 00000001 00000050 e371dda8 00000001
[ 2362.809109]  f3a31000 f3413000 00000001 e371ddb8 000040a8 00000202 00000000 00000023
[ 2362.809113] Call Trace:
[ 2362.809136]  [<fa39016d>] find_parent_nodes+0x34d/0x1280 [btrfs]
[ 2362.809156]  [<fa391172>] btrfs_find_all_roots+0xb2/0x110 [btrfs]
[ 2362.809174]  [<fa3934a8>] btrfs_qgroup_rescan_worker+0x358/0x7a0 [btrfs]
[ 2362.809180]  [<c024d0ce>] ? lock_timer_base.isra.39+0x1e/0x40
[ 2362.809199]  [<fa3648df>] worker_loop+0xff/0x470 [btrfs]
[ 2362.809204]  [<c027a88a>] ? __wake_up_locked+0x1a/0x20
[ 2362.809221]  [<fa3647e0>] ? btrfs_queue_worker+0x2b0/0x2b0 [btrfs]
[ 2362.809225]  [<c025ebbc>] kthread+0x9c/0xb0
[ 2362.809229]  [<c06b487b>] ret_from_kernel_thread+0x1b/0x30
[ 2362.809233]  [<c025eb20>] ? kthread_create_on_node+0x110/0x110

By adding a reschedule point at the end of btrfs_find_all_roots(), i no longer
hit these warnings.

Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

We can only tolerate ENOENT here, for other errors, we should
return directly.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

There is a race condition between resolving indirect ref and root deletion,
and we should gurantee that root can not be destroyed to avoid accessing
broken tree here.

Here we fix it by holding @subvol_srcu, and we will release it as soon
as we have held root node lock.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

The backref walking code will search down to the key it is looking for and then
proceed to walk _all_ of the extents on the file until it hits the end.  This is
suboptimal with large files, we only need to look for as many extents as we have
references for that inode.  I have a testcase that creates a randomly written 4
gig file and before this patch it took 6min 30sec to do the initial send, with
this patch it takes 2min 30sec to do the intial send.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

I don't think this is an issue and I've not seen it in practice but
extent_from_logical will fail to find a skinny extent because it uses
btrfs_previous_item and gives it the normal extent item type.  This is just not
a place to use btrfs_previous_item since we care about either normal extents or
skinny extents, so open code btrfs_previous_item to properly check.  This would
only affect metadata and the only place this is used for metadata is scrub and
I'm pretty sure it's just for printing stuff out, not actually doing any work so
hopefully it was never a problem other than a cosmetic one.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

Currently we have two rb-trees, one for delayed ref heads and one for all of the
delayed refs, including the delayed ref heads.  When we process the delayed refs
we have to hold onto the delayed ref lock for all of the selecting and merging
and such, which results in quite a bit of lock contention.  This was solved by
having a waitqueue and only one flusher at a time, however this hurts if we get
a lot of delayed refs queued up.

So instead just have an rb tree for the delayed ref heads, and then attach the
delayed ref updates to an rb tree that is per delayed ref head.  Then we only
need to take the delayed ref lock when adding new delayed refs and when
selecting a delayed ref head to process, all the rest of the time we deal with a
per delayed ref head lock which will be much less contentious.

The locking rules for this get a little more complicated since we have to lock
up to 3 things to properly process delayed refs, but I will address that problem
later.  For now this passes all of xfstests and my overnight stress tests.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

While running btrfs/004 from xfstests, after 503 iterations, dmesg reported
a deadlock between tasks iterating inode refs and tasks running delayed inodes
(during a transaction commit).

It turns out that iterating inode refs implies doing one tree search and
release all nodes in the path except the leaf node, and then passing that
leaf node to btrfs_ref_to_path(), which in turn does another tree search
without releasing the lock on the leaf node it received as parameter.

This is a problem when other task wants to write to the btree as well and
ends up updating the leaf that is read locked - the writer task locks the
parent of the leaf and then blocks waiting for the leaf's lock to be
released - at the same time, the task executing btrfs_ref_to_path()
does a second tree search, without releasing the lock on the first leaf,
and wants to access a leaf (the same or another one) that is a child of
the same parent, resulting in a deadlock.

The trace reported by lockdep follows.

[84314.936373] INFO: task fsstress:11930 blocked for more than 120 seconds.
[84314.936381]       Tainted: G        W  O 3.12.0-fdm-btrfs-next-16+ #70
[84314.936383] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[84314.936386] fsstress        D ffff8806e1bf8000     0 11930  11926 0x00000000
[84314.936393]  ffff8804d6d89b78 0000000000000046 ffff8804d6d89b18 ffffffff810bd8bd
[84314.936399]  ffff8806e1bf8000 ffff8804d6d89fd8 ffff8804d6d89fd8 ffff8804d6d89fd8
[84314.936405]  ffff880806308000 ffff8806e1bf8000 ffff8804d6d89c08 ffff8804deb8f190
[84314.936410] Call Trace:
[84314.936421]  [<ffffffff810bd8bd>] ? trace_hardirqs_on+0xd/0x10
[84314.936428]  [<ffffffff81774269>] schedule+0x29/0x70
[84314.936451]  [<ffffffffa0715bf5>] btrfs_tree_lock+0x75/0x270 [btrfs]
[84314.936457]  [<ffffffff810715c0>] ? __init_waitqueue_head+0x60/0x60
[84314.936470]  [<ffffffffa06ba231>] btrfs_search_slot+0x7f1/0x930 [btrfs]
[84314.936489]  [<ffffffffa0731c2a>] ? __btrfs_run_delayed_items+0x13a/0x1e0 [btrfs]
[84314.936504]  [<ffffffffa06d2e1f>] btrfs_lookup_inode+0x2f/0xa0 [btrfs]
[84314.936510]  [<ffffffff810bd6ef>] ? trace_hardirqs_on_caller+0x1f/0x1e0
[84314.936528]  [<ffffffffa073173c>] __btrfs_update_delayed_inode+0x4c/0x1d0 [btrfs]
[84314.936543]  [<ffffffffa0731c2a>] ? __btrfs_run_delayed_items+0x13a/0x1e0 [btrfs]
[84314.936558]  [<ffffffffa0731c2a>] ? __btrfs_run_delayed_items+0x13a/0x1e0 [btrfs]
[84314.936573]  [<ffffffffa0731c82>] __btrfs_run_delayed_items+0x192/0x1e0 [btrfs]
[84314.936589]  [<ffffffffa0731d03>] btrfs_run_delayed_items+0x13/0x20 [btrfs]
[84314.936604]  [<ffffffffa06dbcd4>] btrfs_flush_all_pending_stuffs+0x24/0x80 [btrfs]
[84314.936620]  [<ffffffffa06ddc13>] btrfs_commit_transaction+0x223/0xa20 [btrfs]
[84314.936630]  [<ffffffffa06ae5ae>] btrfs_sync_fs+0x6e/0x110 [btrfs]
[84314.936635]  [<ffffffff811d0b50>] ? __sync_filesystem+0x60/0x60
[84314.936639]  [<ffffffff811d0b50>] ? __sync_filesystem+0x60/0x60
[84314.936643]  [<ffffffff811d0b70>] sync_fs_one_sb+0x20/0x30
[84314.936648]  [<ffffffff811a3541>] iterate_supers+0xf1/0x100
[84314.936652]  [<ffffffff811d0c45>] sys_sync+0x55/0x90
[84314.936658]  [<ffffffff8177ef12>] system_call_fastpath+0x16/0x1b
[84314.936660] INFO: lockdep is turned off.
[84314.936663] INFO: task btrfs:11955 blocked for more than 120 seconds.
[84314.936666]       Tainted: G        W  O 3.12.0-fdm-btrfs-next-16+ #70
[84314.936668] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[84314.936670] btrfs           D ffff880541729a88     0 11955  11608 0x00000000
[84314.936674]  ffff880541729a38 0000000000000046 ffff8805417299d8 ffffffff810bd8bd
[84314.936680]  ffff88075430c8a0 ffff880541729fd8 ffff880541729fd8 ffff880541729fd8
[84314.936685]  ffffffff81c104e0 ffff88075430c8a0 ffff8804de8b00b8 ffff8804de8b0000
[84314.936690] Call Trace:
[84314.936695]  [<ffffffff810bd8bd>] ? trace_hardirqs_on+0xd/0x10
[84314.936700]  [<ffffffff81774269>] schedule+0x29/0x70
[84314.936717]  [<ffffffffa0715815>] btrfs_tree_read_lock+0xd5/0x140 [btrfs]
[84314.936721]  [<ffffffff810715c0>] ? __init_waitqueue_head+0x60/0x60
[84314.936733]  [<ffffffffa06ba201>] btrfs_search_slot+0x7c1/0x930 [btrfs]
[84314.936746]  [<ffffffffa06bd505>] btrfs_find_item+0x55/0x160 [btrfs]
[84314.936763]  [<ffffffffa06ff689>] ? free_extent_buffer+0x49/0xc0 [btrfs]
[84314.936780]  [<ffffffffa073c9ca>] btrfs_ref_to_path+0xba/0x1e0 [btrfs]
[84314.936797]  [<ffffffffa06f9719>] ? release_extent_buffer+0xb9/0xe0 [btrfs]
[84314.936813]  [<ffffffffa06ff689>] ? free_extent_buffer+0x49/0xc0 [btrfs]
[84314.936830]  [<ffffffffa073cb50>] inode_to_path+0x60/0xd0 [btrfs]
[84314.936846]  [<ffffffffa073d365>] paths_from_inode+0x115/0x3c0 [btrfs]
[84314.936851]  [<ffffffff8118dd44>] ? kmem_cache_alloc_trace+0x114/0x200
[84314.936868]  [<ffffffffa0714494>] btrfs_ioctl+0xf14/0x2030 [btrfs]
[84314.936873]  [<ffffffff817762db>] ? _raw_spin_unlock+0x2b/0x50
[84314.936877]  [<ffffffff8116598f>] ? handle_mm_fault+0x34f/0xb00
[84314.936882]  [<ffffffff81075563>] ? up_read+0x23/0x40
[84314.936886]  [<ffffffff8177a41c>] ? __do_page_fault+0x20c/0x5a0
[84314.936892]  [<ffffffff811b2946>] do_vfs_ioctl+0x96/0x570
[84314.936896]  [<ffffffff81776e23>] ? error_sti+0x5/0x6
[84314.936901]  [<ffffffff810b71e8>] ? trace_hardirqs_off_caller+0x28/0xd0
[84314.936906]  [<ffffffff81776a09>] ? retint_swapgs+0xe/0x13
[84314.936910]  [<ffffffff811b2eb1>] SyS_ioctl+0x91/0xb0
[84314.936915]  [<ffffffff813eecde>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[84314.936920]  [<ffffffff8177ef12>] system_call_fastpath+0x16/0x1b
[84314.936922] INFO: lockdep is turned off.
[84434.866873] INFO: task btrfs-transacti:11921 blocked for more than 120 seconds.
[84434.866881]       Tainted: G        W  O 3.12.0-fdm-btrfs-next-16+ #70
[84434.866883] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[84434.866886] btrfs-transacti D ffff880755b6a478     0 11921      2 0x00000000
[84434.866893]  ffff8800735b9ce8 0000000000000046 ffff8800735b9c88 ffffffff810bd8bd
[84434.866899]  ffff8805a1b848a0 ffff8800735b9fd8 ffff8800735b9fd8 ffff8800735b9fd8
[84434.866904]  ffffffff81c104e0 ffff8805a1b848a0 ffff880755b6a478 ffff8804cece78f0
[84434.866910] Call Trace:
[84434.866920]  [<ffffffff810bd8bd>] ? trace_hardirqs_on+0xd/0x10
[84434.866927]  [<ffffffff81774269>] schedule+0x29/0x70
[84434.866948]  [<ffffffffa06dd2ef>] wait_current_trans.isra.33+0xbf/0x120 [btrfs]
[84434.866954]  [<ffffffff810715c0>] ? __init_waitqueue_head+0x60/0x60
[84434.866970]  [<ffffffffa06dec18>] start_transaction+0x388/0x5a0 [btrfs]
[84434.866985]  [<ffffffffa06db9b5>] ? transaction_kthread+0xb5/0x280 [btrfs]
[84434.866999]  [<ffffffffa06dee97>] btrfs_attach_transaction+0x17/0x20 [btrfs]
[84434.867012]  [<ffffffffa06dba9e>] transaction_kthread+0x19e/0x280 [btrfs]
[84434.867026]  [<ffffffffa06db900>] ? open_ctree+0x2260/0x2260 [btrfs]
[84434.867030]  [<ffffffff81070dad>] kthread+0xed/0x100
[84434.867035]  [<ffffffff81070cc0>] ? flush_kthread_worker+0x190/0x190
[84434.867040]  [<ffffffff8177ee6c>] ret_from_fork+0x7c/0xb0
[84434.867044]  [<ffffffff81070cc0>] ? flush_kthread_worker+0x190/0x190
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

There are many btrfs functions that manually search the tree for an
item. They all reimplement the same mechanism and differ in the
conditions that they use to find the item. __inode_info() is one such
example. Zach Brown proposed creating a new interface to take the place
of these functions.

This patch is the first step to creating the interface. A new function,
btrfs_find_item, has been added to ctree.c and prototyped in ctree.h.
It is identical to __inode_info, except that the order of the parameters
has been rearranged to more closely those of similar functions elsewhere
in the code (now, root and path come first, then the objectid, offset
and type, and the key to be filled in last). __inode_info's callers have
been set to call this new function instead, and __inode_info itself has
been removed.
Signed-off-by: NKelley Nielsen <kelleynnn@gmail.com>
Suggested-by: NZach Brown <zab@redhat.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <clm@fb.com>

Signed-off-by: NValentina Giusti <valentina.giusti@microon.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <clm@fb.com>

Use WARN_ON()'s return value in place of WARN_ON(1) for cleaner source
code that outputs a more descriptive warnings. Also fix the styling
warning of redundant braces that came up as a result of this fix.
Signed-off-by: NDulshani Gunawardhana <dulshani.gunawardhana89@gmail.com>
Reviewed-by: NZach Brown <zab@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Running balance and defrag concurrently can end up with a crash:

kernel BUG at fs/btrfs/relocation.c:4528!
RIP: 0010:[<ffffffffa01ac33b>]  [<ffffffffa01ac33b>] btrfs_reloc_cow_block+ 0x1eb/0x230 [btrfs]
Call Trace:
  [<ffffffffa01398c1>] ? update_ref_for_cow+0x241/0x380 [btrfs]
  [<ffffffffa0180bad>] ? copy_extent_buffer+0xad/0x110 [btrfs]
  [<ffffffffa0139da1>] __btrfs_cow_block+0x3a1/0x520 [btrfs]
  [<ffffffffa013a0b6>] btrfs_cow_block+0x116/0x1b0 [btrfs]
  [<ffffffffa013ddad>] btrfs_search_slot+0x43d/0x970 [btrfs]
  [<ffffffffa0153c57>] btrfs_lookup_file_extent+0x37/0x40 [btrfs]
  [<ffffffffa0172a5e>] __btrfs_drop_extents+0x11e/0xae0 [btrfs]
  [<ffffffffa013b3fd>] ? generic_bin_search.constprop.39+0x8d/0x1a0 [btrfs]
  [<ffffffff8117d14a>] ? kmem_cache_alloc+0x1da/0x200
  [<ffffffffa0138e7a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
  [<ffffffffa0173ef0>] btrfs_drop_extents+0x60/0x90 [btrfs]
  [<ffffffffa016b24d>] relink_extent_backref+0x2ed/0x780 [btrfs]
  [<ffffffffa0162fe0>] ? btrfs_submit_bio_hook+0x1e0/0x1e0 [btrfs]
  [<ffffffffa01b8ed7>] ? iterate_inodes_from_logical+0x87/0xa0 [btrfs]
  [<ffffffffa016b909>] btrfs_finish_ordered_io+0x229/0xac0 [btrfs]
  [<ffffffffa016c3b5>] finish_ordered_fn+0x15/0x20 [btrfs]
  [<ffffffffa018cbe5>] worker_loop+0x125/0x4e0 [btrfs]
  [<ffffffffa018cac0>] ? btrfs_queue_worker+0x300/0x300 [btrfs]
  [<ffffffff81075ea0>] kthread+0xc0/0xd0
  [<ffffffff81075de0>] ? insert_kthread_work+0x40/0x40
  [<ffffffff8164796c>] ret_from_fork+0x7c/0xb0
  [<ffffffff81075de0>] ? insert_kthread_work+0x40/0x40
----------------------------------------------------------------------

It turns out to be that balance operation will bump root's @last_snapshot,
which enables snapshot-aware defrag path, and backref walking stuff will
find data reloc tree as refs' parent, and hit the BUG_ON() during COW.

As data reloc tree's data is just for relocation purpose, and will be deleted right
after relocation is done, it's unnecessary to walk those refs belonged to data reloc
tree, it'd be better to skip them.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Remove unused eb parameter from btrfs_item_nr
Signed-off-by: NRoss Kirk <ross.kirk@gmail.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

struct __prelim_ref is allocated and freed frequently when
walking backref tree, using slab allocater can not only
speed up allocating but also detect memory leaks.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: NMiao Xie <miaox@cn.fujitsu.com>
Reviewed-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Currently, only add_delayed_refs have to allocate with GFP_ATOMIC,
So just pass arg 'gfp_t' to decide which allocation mode.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: NMiao Xie <miaox@cn.fujitsu.com>
Reviewed-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

u64 is "unsigned long long" on all architectures now, so there's no need to
cast it when formatting it using the "ll" length modifier.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

make C=2 fs/btrfs/ CF=-D__CHECK_ENDIAN__

I tried to filter out the warnings for which patches have already
been sent to the mailing list, pending for inclusion in btrfs-next.

All these changes should be obviously safe.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Because we don't mess with the offset into the extent for compressed we will
properly find both extents for this case

[extent a][extent b][rest of extent a]

but because we already added a ref for the front half we won't add the inode
information for the second half.  This causes us to leak that memory and not
print out the other offset when we do logical-resolve.  So fix this by calling
ulist_add_merge and then add our eie to the existing entry if there is one.
With this patch we get both offsets out of logical-resolve.  With this and the
other 2 patches I've sent we now pass btrfs/276 on my vm with compress-force=lzo
set.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

If you do btrfs inspect-internal logical-resolve on a compressed extent that has
been partly overwritten it won't find anything.  This is because we try and
match the extent offset we've searched for based on the extent offset in the
data extent entry.  However this doesn't work for compressed extents because the
offsets are for the uncompressed size, not the compressed size.  So instead only
do this check if we are not compressed, that way we can get an actual entry for
the physical offset rather than nothing for compressed.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>