[BUG]
btrfs-find-root may not output desire result, as due to
search_extent_cache() may return a result that doesn't cover the desired
range, generation cache can be screwed up if higher generation tree root
is found before lower generation tree root.
For example:
=======
./btrfs-find-root /dev/sda6 -a
Superblock thinks the generation is 8
Superblock thinks the level is 0
adding bytenr: 4194304, gen: 8 <<< Debug output
adding bytenr: 24715264, gen: 7 <<< gen is 7 at read_tree_block time
Well block 4194304(gen: 8 level: 0) seems good, and it matches
superblock
Well block 24715264(gen: 8 level: 0) seems good, and it matches
superblock <<< But its gen is wrong at result output time
=======
[Fix]
Add a new check to make sure the search_extent_cache() is returning the
desired result.
Reported-by: Marc Merlin <marc@merlins.org>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce new find-root.[ch] infrastructure which has better tree root
judgment and uses much less codes to do it.
The new infrastructure will only record tree blocks with highest level
among its generation, and do better judgment whether the found tree block
is the desired one(level + generation check other than the original
generation only check).
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
For any btrfs-$FOO executable, rename the main source file from
$FOO.c to to btrfs-$FOO.c
This makes it slightly more obvious what's building what,
and allows us to write a default rule in the Makefile for
these tools.
(also add btrfs-calc-size to the list of objects to remove
on make clean)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Dave fixed the fs_info to allocate the super copy instead of embedding it, but
he failed to notice that I open code open_ctree in btrfs-find-root so we end up
with a super that's not allocated, so we segfault whenever you try to run
btrfs-find-root. I've fixed this up and now we don't segfault anymore. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Allocate fs_info::super_copy dynamically of full BTRFS_SUPER_INFO_SIZE
and use it directly for saving superblock to disk.
This fixes incorrect superblock checksum after mkfs.
Signed-off-by: David Sterba <dsterba@suse.cz>
__setup_root() was present in find-root.c as well
as disk-io.c. No need for the cut and paste, just
use the one in disk-io.c
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Zach Brown <zab@redhat.com>
David Woodhouse originally contributed this code, and Chris Mason
changed it around to reflect the current design goals for raid56.
The original code expected all metadata and data writes to be full
stripes. This meant metadata block size == stripe size, and had a few
other restrictions.
This version allows metadata blocks smaller than the stripe size. It
implements both raid5 and raid6, although it does not have code to
rebuild from parity if one of the drives is missing or incorrect.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
