There's no point building the path string in each iteration of the
send_hole loop, as it produces always the same string.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
We currently rely too heavily on roots being read-only to save us from just
accessing root->commit_root. We can easily balance blocks out from underneath a
read only root, so to save us from getting screwed make sure we only access
root->commit_root under the commit root sem. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Hugo Mills <hugo@carfax.org.uk>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
So I have an awful exercise script that will run snapshot, balance and
send/receive in parallel. This sometimes would crash spectacularly and when it
came back up the fs would be completely hosed. Turns out this is because of a
bad interaction of balance and send/receive. Send will hold onto its entire
path for the whole send, but its blocks could get relocated out from underneath
it, and because it doesn't old tree locks theres nothing to keep this from
happening. So it will go to read in a slot with an old transid, and we could
have re-allocated this block for something else and it could have a completely
different transid. But because we think it is invalid we clear uptodate and
re-read in the block. If we do this before we actually write out the new block
we could write back stale data to the fs, and boom we're screwed.
Now we definitely need to fix this disconnect between send and balance, but we
really really need to not allow ourselves to accidently read in stale data over
new data. So make sure we check if the extent buffer is not under io before
clearing uptodate, this will kick back EIO to the caller instead of reading in
stale data and keep us from corrupting the fs. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
For an incremental send, fix the process of determining whether the directory
inode we're currently processing needs to have its move/rename operation delayed.
We were ignoring the fact that if the inode's new immediate ancestor has a higher
inode number than ours but wasn't renamed/moved, we might still need to delay our
move/rename, because some other ancestor directory higher in the hierarchy might
have an inode number higher than ours *and* was renamed/moved too - in this case
we have to wait for rename/move of that ancestor to happen before our current
directory's rename/move operation.
Simple steps to reproduce this issue:
$ mkfs.btrfs -f /dev/sdd
$ mount /dev/sdd /mnt
$ mkdir -p /mnt/a/x1/x2
$ mkdir /mnt/a/Z
$ mkdir -p /mnt/a/x1/x2/x3/x4/x5
$ btrfs subvolume snapshot -r /mnt /mnt/snap1
$ btrfs send /mnt/snap1 -f /tmp/base.send
$ mv /mnt/a/x1/x2/x3 /mnt/a/Z/X33
$ mv /mnt/a/x1/x2 /mnt/a/Z/X33/x4/x5/X22
$ btrfs subvolume snapshot -r /mnt /mnt/snap2
$ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send
The incremental send caused the kernel code to enter an infinite loop when
building the path string for directory Z after its references are processed.
A more complex scenario:
$ mkfs.btrfs -f /dev/sdd
$ mount /dev/sdd /mnt
$ mkdir -p /mnt/a/b/c/d
$ mkdir /mnt/a/b/c/d/e
$ mkdir /mnt/a/b/c/d/f
$ mv /mnt/a/b/c/d/e /mnt/a/b/c/d/f/E2
$ mkdir /mmt/a/b/c/g
$ mv /mnt/a/b/c/d /mnt/a/b/D2
$ btrfs subvolume snapshot -r /mnt /mnt/snap1
$ btrfs send /mnt/snap1 -f /tmp/base.send
$ mkdir /mnt/a/o
$ mv /mnt/a/b/c/g /mnt/a/b/D2/f/G2
$ mv /mnt/a/b/D2 /mnt/a/b/dd
$ mv /mnt/a/b/c /mnt/a/C2
$ mv /mnt/a/b/dd/f /mnt/a/o/FF
$ mv /mnt/a/b /mnt/a/o/FF/E2/BB
$ btrfs subvolume snapshot -r /mnt /mnt/snap2
$ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send
A test case for xfstests follows.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
It's possible to change the parent/child relationship between directories
in such a way that if a child directory has a higher inode number than
its parent, it doesn't necessarily means the child rename/move operation
can be performed immediately. The parent migth have its own rename/move
operation delayed, therefore in this case the child needs to have its
rename/move operation delayed too, and be performed after its new parent's
rename/move.
Steps to reproduce the issue:
$ umount /mnt
$ mkfs.btrfs -f /dev/sdd
$ mount /dev/sdd /mnt
$ mkdir /mnt/A
$ mkdir /mnt/B
$ mkdir /mnt/C
$ mv /mnt/C /mnt/A
$ mv /mnt/B /mnt/A/C
$ mkdir /mnt/A/C/D
$ btrfs subvolume snapshot -r /mnt /mnt/snap1
$ btrfs send /mnt/snap1 -f /tmp/base.send
$ mv /mnt/A/C/D /mnt/A/D2
$ mv /mnt/A/C/B /mnt/A/D2/B2
$ mv /mnt/A/C /mnt/A/D2/B2/C2
$ btrfs subvolume snapshot -r /mnt /mnt/snap2
$ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send
The incremental send caused the kernel code to enter an infinite loop when
building the path string for directory C after its references are processed.
The necessary conditions here are that C has an inode number higher than both
A and B, and B as an higher inode number higher than A, and D has the highest
inode number, that is:
inode_number(A) < inode_number(B) < inode_number(C) < inode_number(D)
The same issue could happen if after the first snapshot there's any number
of intermediary parent directories between A2 and B2, and between B2 and C2.
A test case for xfstests follows, covering this simple case and more advanced
ones, with files and hard links created inside the directories.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
No need to search in the send tree for the generation number of the inode,
we already have it in the recorded_ref structure passed to us.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Btrfs send reads data from disk and then writes to a stream via pipe or
a file via flush.
Currently we're going to read each page a time, so every page results
in a disk read, which is not friendly to disks, esp. HDD. Given that,
the performance can be gained by adding readahead for those pages.
Here is a quick test:
$ btrfs subvolume create send
$ xfs_io -f -c "pwrite 0 1G" send/foobar
$ btrfs subvolume snap -r send ro
$ time "btrfs send ro -f /dev/null"
w/o w
real 1m37.527s 0m9.097s
user 0m0.122s 0m0.086s
sys 0m53.191s 0m12.857s
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
This has no functional change, only picks out the same part of two functions,
and makes it shared.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
When we're finishing processing of an inode, if we're dealing with a
directory inode that has a pending move/rename operation, we don't
need to send a utimes update instruction to the send stream, as we'll
do it later after doing the move/rename operation. Therefore we save
some time here building paths and doing btree lookups.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
It is really unnecessary to search tree again for @gen, @mode and @rdev
in the case of REG inodes' creation, as we've got btrfs_inode_item in sctx,
and @gen, @mode and @rdev can easily be fetched.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
In "btrfs: send: lower memory requirements in common case" the code to
save the old_buf_len was incorrectly moved to a wrong place and broke
the original logic.
Reported-by: Filipe David Manana <fdmanana@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Filipe David Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
When doing an incremental send, if we had a directory pending a move/rename
operation and none of its parents, except for the immediate parent, were
pending a move/rename, after processing the directory's references, we would
be issuing utimes, chown and chmod intructions against am outdated path - a
path which matched the one in the parent root.
This change also simplifies a bit the code that deals with building a path
for a directory which has a move/rename operation delayed.
Steps to reproduce:
$ mkfs.btrfs -f /dev/sdb3
$ mount /dev/sdb3 /mnt/btrfs
$ mkdir -p /mnt/btrfs/a/b/c/d/e
$ mkdir /mnt/btrfs/a/b/c/f
$ chmod 0777 /mnt/btrfs/a/b/c/d/e
$ btrfs subvolume snapshot -r /mnt/btrfs /mnt/btrfs/snap1
$ btrfs send /mnt/btrfs/snap1 -f /tmp/base.send
$ mv /mnt/btrfs/a/b/c/f /mnt/btrfs/a/b/f2
$ mv /mnt/btrfs/a/b/c/d/e /mnt/btrfs/a/b/f2/e2
$ mv /mnt/btrfs/a/b/c /mnt/btrfs/a/b/c2
$ mv /mnt/btrfs/a/b/c2/d /mnt/btrfs/a/b/c2/d2
$ chmod 0700 /mnt/btrfs/a/b/f2/e2
$ 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: chmod a/b/c/d/e failed. No such file or directory
A test case for xfstests follows.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
The incremental send algorithm assumed that it was possible to issue
a directory remove (rmdir) if the the inode number it was currently
processing was greater than (or equal) to any inode that referenced
the directory's inode. This wasn't a valid assumption because any such
inode might be a child directory that is pending a move/rename operation,
because it was moved into a directory that has a higher inode number and
was moved/renamed too - in other words, the case the following commit
addressed:
9f03740a95
(Btrfs: fix infinite path build loops in incremental send)
This made an incremental send issue an rmdir operation before the
target directory was actually empty, which made btrfs receive fail.
Therefore it needs to wait for all pending child directory inodes to
be moved/renamed before sending an rmdir operation.
Simple steps to reproduce this issue:
$ mkfs.btrfs -f /dev/sdb3
$ mount /dev/sdb3 /mnt/btrfs
$ mkdir -p /mnt/btrfs/a/b/c/x
$ mkdir /mnt/btrfs/a/b/y
$ btrfs subvolume snapshot -r /mnt/btrfs /mnt/btrfs/snap1
$ btrfs send /mnt/btrfs/snap1 -f /tmp/base.send
$ mv /mnt/btrfs/a/b/y /mnt/btrfs/a/b/YY
$ mv /mnt/btrfs/a/b/c/x /mnt/btrfs/a/b/YY
$ 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. Directory not empty
A test case for xfstests follows.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
This reverts commit 41ce9970a8.
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: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef 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: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
This was a leftover from the commit:
74dd17fbe3
(Btrfs: fix btrfs send for inline items and compression)
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef 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: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef 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: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef 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: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
We don't need to keep track of that, it's available via is_vmalloc_addr.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef 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: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef 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: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris 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: Josef Bacik <jbacik@fb.com>
Reviewed-by: Filipe Manana <fdmanana@gmail.com>
Signed-off-by: Chris 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris 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: Jens Axboe <axboe@fb.com>
Signed-off-by: Chris 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We will finish orphan cleanups during snapshot, so we don't
have to commit transaction here.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Frank Holton <fholton@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris 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: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Unused since ed2590953b
"Btrfs: stop using vfs_read in send".
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
