When doing an incremental send, if we delete a directory that has N > 1
hardlinks for the same file and that file has the highest inode number
inside the directory contents, an incremental send would send N times an
rmdir operation against the directory. This made the btrfs receive command
fail on the second rmdir instruction, as the target directory didn't exist
anymore.

Steps to reproduce the issue:

    $ mkfs.btrfs -f /dev/sdb3
    $ mount /dev/sdb3 /mnt/btrfs
    $ mkdir -p /mnt/btrfs/a/b/c
    $ echo 'ola mundo' > /mnt/btrfs/a/b/c/foo.txt
    $ ln /mnt/btrfs/a/b/c/foo.txt /mnt/btrfs/a/b/c/bar.txt
    $ btrfs subvolume snapshot -r /mnt/btrfs /mnt/btrfs/snap1
    $ btrfs send /mnt/btrfs/snap1 -f /tmp/base.send
    $ rm -f /mnt/btrfs/a/b/c/foo.txt
    $ rm -f /mnt/btrfs/a/b/c/bar.txt
    $ rmdir /mnt/btrfs/a/b/c
    $ btrfs subvolume snapshot -r /mnt/btrfs /mnt/btrfs/snap2
    $ btrfs send -p /mnt/btrfs/snap1 /mnt/btrfs/snap2 -f /tmp/incremental.send

    $ umount /mnt/btrfs
    $ mkfs.btrfs -f /dev/sdb3
    $ mount /dev/sdb3 /mnt/btrfs
    $ btrfs receive /mnt/btrfs -f /tmp/base.send
    $ btrfs receive /mnt/btrfs -f /tmp/incremental.send

The second btrfs receive command failed with:

    ERROR: rmdir o259-6-0 failed. No such file or directory

A test case for xfstests follows.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

This fixes yet one more case not caught by the commit titled:

   Btrfs: fix infinite path build loops in incremental send

In this case, even before the initial full send, we have a directory
which is a child of a directory with a higher inode number. Then we
perform the initial send, and after we rename both the child and the
parent, without moving them around. After doing these 2 renames, an
incremental send sent a rename instruction for the child directory
which contained an invalid "from" path (referenced the parent's old
name, not the new one), which made the btrfs receive command fail.

Steps to reproduce:

    $ mkfs.btrfs -f /dev/sdb3
    $ mount /dev/sdb3 /mnt/btrfs
    $ mkdir -p /mnt/btrfs/a/b
    $ mkdir /mnt/btrfs/d
    $ mkdir /mnt/btrfs/a/b/c
    $ mv /mnt/btrfs/d /mnt/btrfs/a/b/c
    $ btrfs subvolume snapshot -r /mnt/btrfs /mnt/btrfs/snap1
    $ btrfs send /mnt/btrfs/snap1 -f /tmp/base.send
    $ mv /mnt/btrfs/a/b/c /mnt/btrfs/a/b/x
    $ mv /mnt/btrfs/a/b/x/d /mnt/btrfs/a/b/x/y
    $ btrfs subvolume snapshot -r /mnt/btrfs /mnt/btrfs/snap2
    $ btrfs send -p /mnt/btrfs/snap1 /mnt/btrfs/snap2 -f /tmp/incremental.send

    $ umout /mnt/btrfs
    $ mkfs.btrfs -f /dev/sdb3
    $ mount /dev/sdb3 /mnt/btrfs
    $ btrfs receive /mnt/btrfs -f /tmp/base.send
    $ btrfs receive /mnt/btrfs -f /tmp/incremental.send

The second btrfs receive command failed with:
  "ERROR: rename a/b/c/d -> a/b/x/y failed. No such file or directory"

A test case for xfstests follows.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

This reverts commit 41ce9970.
Previously i was thinking we can use readonly root's commit root
safely while it is not true, readonly root may be cowed with the
following cases.

1.snapshot send root will cow source root.
2.balance,device operations will also cow readonly send root
to relocate.

So i have two ideas to make us safe to use commit root.

-->approach 1:
make it protected by transaction and end transaction properly and we research
next item from root node(see btrfs_search_slot_for_read()).

-->approach 2:
add another counter to local root structure to sync snapshot with send.
and add a global counter to sync send with exclusive device operations.

So with approach 2, send can use commit root safely, because we make sure
send root can not be cowed during send. Unfortunately, it make codes *ugly*
and more complex to maintain.

To make snapshot and send exclusively, device operations and send operation
exclusively with each other is a little confusing for common users.

So why not drop into previous way.

Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

The fs_path structure uses an inline buffer and falls back to a chain of
allocations, but vmalloc is not necessary because PATH_MAX fits into
PAGE_SIZE.

The size of fs_path has been reduced to 256 bytes from PAGE_SIZE,
usually 4k. Experimental measurements show that most paths on a single
filesystem do not exceed 200 bytes, and these get stored into the inline
buffer directly, which is now 230 bytes. Longer paths are kmalloced when
needed.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

We have this pattern where we do search for a contiguous group of
items in a tree and everytime we find an item, we process it, then
we release our path, increment the offset of the search key, do
another full tree search and repeat these steps until a tree search
can't find more items we're interested in.

Instead of doing these full tree searches after processing each item,
just process the next item/slot in our leaf and don't release the path.
Since all these trees are read only and we always use the commit root
for a search and skip node/leaf locks, we're not affecting concurrency
on the trees.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

This was a leftover from the commit:

   74dd17fb
   (Btrfs: fix btrfs send for inline items and compression)
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

If cleaning the name cache fails, we could try to proceed at the cost of
some memory leak. This is not expected to happen often.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

There are only 2 static callers, the BUG would normally be never
reached, but let's be nice.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

We know that buf_len is at most PATH_MAX, 4k, and can merge it with the
reversed member. This saves 3 bytes in favor of inline_buf.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

We don't need to keep track of that, it's available via is_vmalloc_addr.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

The member is used only to return value back from
fs_path_prepare_for_add, we can do it locally and save 8 bytes for the
inline_buf path.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

The buffer passed to snprintf can hold the fully expanded format string,
64 = 3x largest ULL + 3x char + trailing null.  I don't think that removing the
check entirely is a good idea, hence the ASSERT.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

The commit titled "Btrfs: fix infinite path build loops in incremental send"
didn't cover a particular case where the parent-child relationship inversion
of directories doesn't imply a rename of the new parent directory. This was
due to a simple logic mistake, a logical and instead of a logical or.

Steps to reproduce:

  $ mkfs.btrfs -f /dev/sdb3
  $ mount /dev/sdb3 /mnt/btrfs
  $ mkdir -p /mnt/btrfs/a/b/bar1/bar2/bar3/bar4
  $ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap1
  $ mv /mnt/btrfs/a/b/bar1/bar2/bar3/bar4 /mnt/btrfs/a/b/k44
  $ mv /mnt/btrfs/a/b/bar1/bar2/bar3 /mnt/btrfs/a/b/k44
  $ mv /mnt/btrfs/a/b/bar1/bar2 /mnt/btrfs/a/b/k44/bar3
  $ mv /mnt/btrfs/a/b/bar1 /mnt/btrfs/a/b/k44/bar3/bar2/k11
  $ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap2
  $ btrfs send -p /mnt/btrfs/snap1 /mnt/btrfs/snap2 > /tmp/incremental.send

A patch to update the test btrfs/030 from xfstests, so that it covers
this case, will be submitted soon.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

This fixes a case that the commit titled:

   Btrfs: fix infinite path build loops in incremental send

didn't cover. If the parent-child relationship between 2 directories
is inverted, both get renamed, and the former parent has a file that
got renamed too (but remains a child of that directory), the incremental
send operation would use the file's old path after sending an unlink
operation for that old path, causing receive to fail on future operations
like changing owner, permissions or utimes of the corresponding inode.

This is not a regression from the commit mentioned before, as without
that commit we would fall into the issues that commit fixed, so it's
just one case that wasn't covered before.

Simple steps to reproduce this issue are:

      $ mkfs.btrfs -f /dev/sdb3
      $ mount /dev/sdb3 /mnt/btrfs
      $ mkdir -p /mnt/btrfs/a/b/c/d
      $ touch /mnt/btrfs/a/b/c/d/file
      $ mkdir -p /mnt/btrfs/a/b/x
      $ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap1
      $ mv /mnt/btrfs/a/b/x /mnt/btrfs/a/b/c/x2
      $ mv /mnt/btrfs/a/b/c/d /mnt/btrfs/a/b/c/x2/d2
      $ mv /mnt/btrfs/a/b/c/x2/d2/file /mnt/btrfs/a/b/c/x2/d2/file2
      $ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap2
      $ btrfs send -p /mnt/btrfs/snap1 /mnt/btrfs/snap2 > /tmp/incremental.send

A patch to update the test btrfs/030 from xfstests, so that it covers
this case, will be submitted soon.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

Function wait_for_parent_move() returns negative value if an error
happened, 0 if we don't need to wait for the parent's move, and
1 if the wait is needed.
Before this change an error return value was being treated like the
return value 1, which was not correct.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>

For non compressed extents, iterate_extent_inodes() gives us offsets
that take into account the data offset from the file extent items, while
for compressed extents it doesn't. Therefore we have to adjust them before
placing them in a send clone instruction. Not doing this adjustment leads to
the receiving end requesting for a wrong a file range to the clone ioctl,
which results in different file content from the one in the original send
root.

Issue reproducible with the following excerpt from the test I made for
xfstests:

  _scratch_mkfs
  _scratch_mount "-o compress-force=lzo"

  $XFS_IO_PROG -f -c "truncate 118811" $SCRATCH_MNT/foo
  $XFS_IO_PROG -c "pwrite -S 0x0d -b 39987 92267 39987" $SCRATCH_MNT/foo

  $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap1

  $XFS_IO_PROG -c "pwrite -S 0x3e -b 80000 200000 80000" $SCRATCH_MNT/foo
  $BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT
  $XFS_IO_PROG -c "pwrite -S 0xdc -b 10000 250000 10000" $SCRATCH_MNT/foo
  $XFS_IO_PROG -c "pwrite -S 0xff -b 10000 300000 10000" $SCRATCH_MNT/foo

  # will be used for incremental send to be able to issue clone operations
  $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/clones_snap

  $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap2

  $FSSUM_PROG -A -f -w $tmp/1.fssum $SCRATCH_MNT/mysnap1
  $FSSUM_PROG -A -f -w $tmp/2.fssum -x $SCRATCH_MNT/mysnap2/mysnap1 \
      -x $SCRATCH_MNT/mysnap2/clones_snap $SCRATCH_MNT/mysnap2
  $FSSUM_PROG -A -f -w $tmp/clones.fssum $SCRATCH_MNT/clones_snap \
      -x $SCRATCH_MNT/clones_snap/mysnap1 -x $SCRATCH_MNT/clones_snap/mysnap2

  $BTRFS_UTIL_PROG send $SCRATCH_MNT/mysnap1 -f $tmp/1.snap
  $BTRFS_UTIL_PROG send $SCRATCH_MNT/clones_snap -f $tmp/clones.snap
  $BTRFS_UTIL_PROG send -p $SCRATCH_MNT/mysnap1 \
      -c $SCRATCH_MNT/clones_snap $SCRATCH_MNT/mysnap2 -f $tmp/2.snap

  _scratch_unmount
  _scratch_mkfs
  _scratch_mount

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/1.snap
  $FSSUM_PROG -r $tmp/1.fssum $SCRATCH_MNT/mysnap1 2>> $seqres.full

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/clones.snap
  $FSSUM_PROG -r $tmp/clones.fssum $SCRATCH_MNT/clones_snap 2>> $seqres.full

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/2.snap
  $FSSUM_PROG -r $tmp/2.fssum $SCRATCH_MNT/mysnap2 2>> $seqres.full
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

Wang noticed that he was failing btrfs/030 even though me and Filipe couldn't
reproduce.  Turns out this is because Wang didn't have CONFIG_BTRFS_ASSERT set,
which meant that a key part of Filipe's original patch was not being built in.
This appears to be a mess up with merging Filipe's patch as it does not exist in
his original patch.  Fix this by changing how we make sure del_waiting_dir_move
asserts that it did not error and take the function out of the ifdef check.
This makes btrfs/030 pass with the assert on or off.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Reviewed-by: NFilipe Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

After the commit titled "Btrfs: fix btrfs boot when compiled as built-in",
LIBCRC32C requirement was removed from btrfs' Kconfig. This made it not
possible to build a kernel with btrfs enabled (either as module or built-in)
if libcrc32c is not enabled as well. So just replace all uses of libcrc32c
with the equivalent function in btrfs hash.h - btrfs_crc32c.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

If we truncate an uncompressed inline item, ram_bytes isn't updated to reflect
the new size.  The fixe uses the size directly from the item header when
reading uncompressed inlines, and also fixes truncate to update the
size as it goes.
Reported-by: NJens Axboe <axboe@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>
CC: stable@vger.kernel.org

There was a case where file hole detection was incorrect and it would
cause an incremental send to override a section of a file with zeroes.

This happened in the case where between the last leaf we processed which
contained a file extent item for our current inode and the leaf we're
currently are at (and has a file extent item for our current inode) there
are only leafs containing exclusively file extent items for our current
inode, and none of them was updated since the previous send operation.
The file hole detection code would incorrectly consider the file range
covered by these leafs as a hole.

A test case for xfstests follows soon.
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>

Instead of looking for a file extent item, process it, release the path
and do a btree search for the next file extent item, just process all
file extent items in a leaf without intermediate btree searches. This way
we save cpu and we're not blocking other tasks or affecting concurrency on
the btree, because send's paths use the commit root and skip btree node/leaf
locking.
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>

The send operation processes inodes by their ascending number, and assumes
that any rename/move operation can be successfully performed (sent to the
caller) once all previous inodes (those with a smaller inode number than the
one we're currently processing) were processed.

This is not true when an incremental send had to process an hierarchical change
between 2 snapshots where the parent-children relationship between directory
inodes was reversed - that is, parents became children and children became
parents. This situation made the path building code go into an infinite loop,
which kept allocating more and more memory that eventually lead to a krealloc
warning being displayed in dmesg:

  WARNING: CPU: 1 PID: 5705 at mm/page_alloc.c:2477 __alloc_pages_nodemask+0x365/0xad0()
  Modules linked in: btrfs raid6_pq xor pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) snd_hda_codec_hdmi snd_hda_codec_realtek joydev radeon snd_hda_intel snd_hda_codec snd_hwdep snd_seq_midi snd_pcm psmouse i915 snd_rawmidi serio_raw snd_seq_midi_event lpc_ich snd_seq snd_timer ttm snd_seq_device rfcomm drm_kms_helper parport_pc bnep bluetooth drm ppdev snd soundcore i2c_algo_bit snd_page_alloc binfmt_misc video lp parport r8169 mii hid_generic usbhid hid
  CPU: 1 PID: 5705 Comm: btrfs Tainted: G           O 3.13.0-rc7-fdm-btrfs-next-18+ #3
  Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./Z77 Pro4, BIOS P1.50 09/04/2012
  [ 5381.660441]  00000000000009ad ffff8806f6f2f4e8 ffffffff81777434 0000000000000007
  [ 5381.660447]  0000000000000000 ffff8806f6f2f528 ffffffff8104a9ec ffff8807038f36f0
  [ 5381.660452]  0000000000000000 0000000000000206 ffff8807038f2490 ffff8807038f36f0
  [ 5381.660457] Call Trace:
  [ 5381.660464]  [<ffffffff81777434>] dump_stack+0x4e/0x68
  [ 5381.660471]  [<ffffffff8104a9ec>] warn_slowpath_common+0x8c/0xc0
  [ 5381.660476]  [<ffffffff8104aa3a>] warn_slowpath_null+0x1a/0x20
  [ 5381.660480]  [<ffffffff81144995>] __alloc_pages_nodemask+0x365/0xad0
  [ 5381.660487]  [<ffffffff8108313f>] ? local_clock+0x4f/0x60
  [ 5381.660491]  [<ffffffff811430e8>] ? free_one_page+0x98/0x440
  [ 5381.660495]  [<ffffffff8108313f>] ? local_clock+0x4f/0x60
  [ 5381.660502]  [<ffffffff8113fae4>] ? __get_free_pages+0x14/0x50
  [ 5381.660508]  [<ffffffff81095fb8>] ? trace_hardirqs_off_caller+0x28/0xd0
  [ 5381.660515]  [<ffffffff81183caf>] alloc_pages_current+0x10f/0x1f0
  [ 5381.660520]  [<ffffffff8113fae4>] ? __get_free_pages+0x14/0x50
  [ 5381.660524]  [<ffffffff8113fae4>] __get_free_pages+0x14/0x50
  [ 5381.660530]  [<ffffffff8115dace>] kmalloc_order_trace+0x3e/0x100
  [ 5381.660536]  [<ffffffff81191ea0>] __kmalloc_track_caller+0x220/0x230
  [ 5381.660560]  [<ffffffffa0729fdb>] ? fs_path_ensure_buf.part.12+0x6b/0x200 [btrfs]
  [ 5381.660564]  [<ffffffff8178085c>] ? retint_restore_args+0xe/0xe
  [ 5381.660569]  [<ffffffff811580ef>] krealloc+0x6f/0xb0
  [ 5381.660586]  [<ffffffffa0729fdb>] fs_path_ensure_buf.part.12+0x6b/0x200 [btrfs]
  [ 5381.660601]  [<ffffffffa072a208>] fs_path_prepare_for_add+0x98/0xb0 [btrfs]
  [ 5381.660615]  [<ffffffffa072a2bc>] fs_path_add_path+0x2c/0x60 [btrfs]
  [ 5381.660628]  [<ffffffffa072c55c>] get_cur_path+0x7c/0x1c0 [btrfs]

Even without this loop, the incremental send couldn't succeed, because it would attempt
to send a rename/move operation for the lower inode before the highest inode number was
renamed/move. This issue is easy to trigger with the following steps:

  $ mkfs.btrfs -f /dev/sdb3
  $ mount /dev/sdb3 /mnt/btrfs
  $ mkdir -p /mnt/btrfs/a/b/c/d
  $ mkdir /mnt/btrfs/a/b/c2
  $ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap1
  $ mv /mnt/btrfs/a/b/c/d /mnt/btrfs/a/b/c2/d2
  $ mv /mnt/btrfs/a/b/c /mnt/btrfs/a/b/c2/d2/cc
  $ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap2
  $ btrfs send -p /mnt/btrfs/snap1 /mnt/btrfs/snap2 > /tmp/incremental.send

The structure of the filesystem when the first snapshot is taken is:

	 .                       (ino 256)
	 |-- a                   (ino 257)
	     |-- b               (ino 258)
	         |-- c           (ino 259)
	         |   |-- d       (ino 260)
                 |
	         |-- c2          (ino 261)

And its structure when the second snapshot is taken is:

	 .                       (ino 256)
	 |-- a                   (ino 257)
	     |-- b               (ino 258)
	         |-- c2          (ino 261)
	             |-- d2      (ino 260)
	                 |-- cc  (ino 259)

Before the move/rename operation is performed for the inode 259, the
move/rename for inode 260 must be performed, since 259 is now a child
of 260.

A test case for xfstests, with a more complex scenario, will follow soon.
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>

The buffer size argument passed to snprintf must account for the
trailing null byte added by snprintf, and it returns a value >= then
sizeof(buffer) when the string can't fit in the buffer.

Since our buffer has a size of 64 characters, and the maximum orphan
name we can generate is 63 characters wide, we must pass 64 as the
buffer size to snprintf, and not 63.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

To search tree root without transaction protection, we should neither search commit
root nor skip locking here, fix it.
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>

It is possible for the send feature to send clone operations that
request a cloning range (offset + length) that is not aligned with
the block size. This makes the btrfs receive command send issue a
clone ioctl call that will fail, as the ioctl will return an -EINVAL
error because of the unaligned range.

Fix this by not sending clone operations for non block aligned ranges,
and instead send regular write operation for these (less common) cases.

The following xfstest reproduces this issue, which fails on the second
btrfs receive command without this change:

  seq=`basename $0`
  seqres=$RESULT_DIR/$seq
  echo "QA output created by $seq"

  tmp=`mktemp -d`

  status=1	# failure is the default!
  trap "_cleanup; exit \$status" 0 1 2 3 15

  _cleanup()
  {
      rm -fr $tmp
  }

  # get standard environment, filters and checks
  . ./common/rc
  . ./common/filter

  # real QA test starts here
  _supported_fs btrfs
  _supported_os Linux
  _require_scratch
  _need_to_be_root

  rm -f $seqres.full

  _scratch_mkfs >/dev/null 2>&1
  _scratch_mount

  $XFS_IO_PROG -f -c "truncate 819200" $SCRATCH_MNT/foo | _filter_xfs_io
  $BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT | _filter_scratch

  $XFS_IO_PROG -c "falloc -k 819200 667648" $SCRATCH_MNT/foo | _filter_xfs_io
  $BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT | _filter_scratch

  $XFS_IO_PROG -f -c "pwrite 1482752 2978" $SCRATCH_MNT/foo | _filter_xfs_io
  $BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT | _filter_scratch

  $BTRFS_UTIL_PROG subvol snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap1 | \
      _filter_scratch

  $XFS_IO_PROG -f -c "truncate 883305" $SCRATCH_MNT/foo | _filter_xfs_io
  $BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT | _filter_scratch

  $BTRFS_UTIL_PROG subvol snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap2 | \
      _filter_scratch

  $BTRFS_UTIL_PROG send $SCRATCH_MNT/mysnap1 -f $tmp/1.snap 2>&1 | _filter_scratch
  $BTRFS_UTIL_PROG send -p $SCRATCH_MNT/mysnap1 $SCRATCH_MNT/mysnap2 \
      -f $tmp/2.snap 2>&1 | _filter_scratch

  md5sum $SCRATCH_MNT/foo | _filter_scratch
  md5sum $SCRATCH_MNT/mysnap1/foo | _filter_scratch
  md5sum $SCRATCH_MNT/mysnap2/foo | _filter_scratch

  _scratch_unmount
  _check_btrfs_filesystem $SCRATCH_DEV
  _scratch_mkfs >/dev/null 2>&1
  _scratch_mount

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/1.snap
  md5sum $SCRATCH_MNT/mysnap1/foo | _filter_scratch

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/2.snap
  md5sum $SCRATCH_MNT/mysnap2/foo | _filter_scratch

  _scratch_unmount
  _check_btrfs_filesystem $SCRATCH_DEV

  status=0
  exit

The tests expected output is:

  QA output created by 025
  FSSync 'SCRATCH_MNT'
  FSSync 'SCRATCH_MNT'
  wrote 2978/2978 bytes at offset 1482752
  XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
  FSSync 'SCRATCH_MNT'
  Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/mysnap1'
  FSSync 'SCRATCH_MNT'
  Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/mysnap2'
  At subvol SCRATCH_MNT/mysnap1
  At subvol SCRATCH_MNT/mysnap2
  129b8eaee8d3c2bcad49bec596591cb3  SCRATCH_MNT/foo
  42b6369eae2a8725c1aacc0440e597aa  SCRATCH_MNT/mysnap1/foo
  129b8eaee8d3c2bcad49bec596591cb3  SCRATCH_MNT/mysnap2/foo
  At subvol mysnap1
  42b6369eae2a8725c1aacc0440e597aa  SCRATCH_MNT/mysnap1/foo
  At snapshot mysnap2
  129b8eaee8d3c2bcad49bec596591cb3  SCRATCH_MNT/mysnap2/foo
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>

We will finish orphan cleanups during snapshot, so we don't
have to commit transaction here.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

We should gurantee that parent and clone roots can not be destroyed
during send, for this we have two ideas.

1.by holding @subvol_sem, this might be a nightmare, because it will
block all subvolumes deletion for a long time.

2.Miao pointed out we can reuse @send_in_progress, that mean we will
skip snapshot deletion if root sending is in progress.

Here we adopt the second approach since it won't block other subvolumes
deletion for a long time.

Besides in btrfs_clean_one_deleted_snapshot(), we only check first root
, if this root is involved in send, we return directly rather than
continue to check.There are several reasons about it:

1.this case happen seldomly.
2.after sending,cleaner thread can continue to drop that root.
3.make code simple

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

Steps to reproduce:
 # mkfs.btrfs -f /dev/sda8
 # mount /dev/sda8 /mnt
 # btrfs sub snapshot -r /mnt /mnt/snap1
 # btrfs sub snapshot -r /mnt /mnt/snap2
 # btrfs send /mnt/snap1 -p /mnt/snap2 -f /mnt/1
 # dmesg

The problem is that we will sort clone roots(include @send_root), it
might push @send_root before thus @send_root's @send_in_progress will
be decreased twice.

Cc: David Sterba <dsterba@suse.cz>
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>

Convert all applicable cases of printk and pr_* to the btrfs_* macros.

Fix all uses of the BTRFS prefix.
Signed-off-by: NFrank Holton <fholton@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

Warn if the balance goes below zero, which appears to be unlikely
though. Otherwise cleans up the code a bit.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

Since daivd did the work that force us to use readonly snapshot,
we can safely remove transaction protection from btrfs send.
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>

All the subvolues that are involved in send must be read-only during the
whole operation. The ioctl SUBVOL_SETFLAGS could be used to change the
status to read-write and the result of send stream is undefined if the
data change unexpectedly.

Fix that by adding a refcount for all involved roots and verify that
there's no send in progress during SUBVOL_SETFLAGS ioctl call that does
read-only -> read-write transition.

We need refcounts because there are no restrictions on number of send
parallel operations currently run on a single subvolume, be it source,
parent or one of the multiple clone sources.

Kernel is silent when the RO checks fail and returns EPERM. The same set
of checks is done already in userspace before send starts.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

Unused since ed259095
"Btrfs: stop using vfs_read in send".
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

Remove ifdefed code:

- tlv_put for 8, 16 and 32, add a generic tempalte if needed in future
- tlv_put_timespec - the btrfs_timespec fields are used
- fs_path_remove obsoleted long ago
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

fs/btrfs/send.c:2190:9: warning: incorrect type in argument 3 (different base types)
fs/btrfs/send.c:2190:9:    expected unsigned long long [unsigned] [usertype] value
fs/btrfs/send.c:2190:9:    got restricted __le64 [usertype] ctransid
fs/btrfs/send.c:2195:17: warning: incorrect type in argument 3 (different base types)
fs/btrfs/send.c:2195:17:    expected unsigned long long [unsigned] [usertype] value
fs/btrfs/send.c:2195:17:    got restricted __le64 [usertype] ctransid
fs/btrfs/send.c:3716:9: warning: incorrect type in argument 3 (different base types)
fs/btrfs/send.c:3716:9:    expected unsigned long long [unsigned] [usertype] value
fs/btrfs/send.c:3716:9:    got restricted __le64 [usertype] ctransid
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>

Btrfs has always had these filler extent data items for holes in inodes.  This
has made somethings very easy, like logging hole punches and sending hole
punches.  However for large holey files these extent data items are pure
overhead.  So add an incompatible feature to no longer add hole extents to
reduce the amount of metadata used by these sort of files.  This has a few
changes for logging and send obviously since they will need to detect holes and
log/send the holes if there are any.  I've tested this thoroughly with xfstests
and it doesn't cause any issues with and without the incompat format set.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <clm@fb.com>

The closing parenthesis is in the wrong place.  We want to check
"sizeof(*arg->clone_sources) * arg->clone_sources_count" instead of
"sizeof(*arg->clone_sources * arg->clone_sources_count)".
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NJie Liu <jeff.liu@oracle.com>
Signed-off-by: NChris Mason <clm@fb.com>
cc: stable@vger.kernel.org

I hit this problem with my no holes patch and it made me realize what the
problem was for bz 60834.  If the first item in the leaf is an inline extent and
we try to read anything starting from disk_bytenr onward we will read off the
end of the leaf.  So we need to check to see what it's type is, and if it's not
REG we can just break out.  This should fix this problem.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.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>

Apparently we don't actually close the files until we return to userspace, so
stop using vfs_read in send.  This is actually better for us since we can avoid
all the extra logic of holding the file we're sending open and making sure to
clean it up.  This will fix people who have been hitting too many files open
errors when trying to send.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>