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Performance oriented customized Linux kernel based on the mainline kernel.
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Qu Wenruo ea57788eb7 btrfs: require only sector size alignment for parent eb bytenr 
[BUG]
A completely sane converted fs will cause kernel warning at balance
time:

  [ 1557.188633] BTRFS info (device sda7): relocating block group 8162107392 flags data
  [ 1563.358078] BTRFS info (device sda7): found 11722 extents
  [ 1563.358277] BTRFS info (device sda7): leaf 7989321728 gen 95 total ptrs 213 free space 3458 owner 2
  [ 1563.358280] 	item 0 key (7984947200 169 0) itemoff 16250 itemsize 33
  [ 1563.358281] 		extent refs 1 gen 90 flags 2
  [ 1563.358282] 		ref#0: tree block backref root 4
  [ 1563.358285] 	item 1 key (7985602560 169 0) itemoff 16217 itemsize 33
  [ 1563.358286] 		extent refs 1 gen 93 flags 258
  [ 1563.358287] 		ref#0: shared block backref parent 7985602560
  [ 1563.358288] 			(parent 7985602560 is NOT ALIGNED to nodesize 16384)
  [ 1563.358290] 	item 2 key (7985635328 169 0) itemoff 16184 itemsize 33
  ...
  [ 1563.358995] BTRFS error (device sda7): eb 7989321728 invalid extent inline ref type 182
  [ 1563.358996] ------------[ cut here ]------------
  [ 1563.359005] WARNING: CPU: 14 PID: 2930 at 0xffffffff9f231766

Then with transaction abort, and obviously failed to balance the fs.

[CAUSE]
That mentioned inline ref type 182 is completely sane, it's
BTRFS_SHARED_BLOCK_REF_KEY, it's some extra check making kernel to
believe it's invalid.

Commit 64ecdb647d ("Btrfs: add one more sanity check for shared ref
type") introduced extra checks for backref type.

One of the requirement is, parent bytenr must be aligned to node size,
which is not correct.

One example is like this:

0	1G  1G+4K		2G 2G+4K
	|   |///////////////////|//|  <- A chunk starts at 1G+4K
            |   |	<- A tree block get reserved at bytenr 1G+4K

Then we have a valid tree block at bytenr 1G+4K, but not aligned to
nodesize (16K).

Such chunk is not ideal, but current kernel can handle it pretty well.
We may warn about such tree block in the future, but should not reject
them.

[FIX]
Change the alignment requirement from node size alignment to sector size
alignment.

Also, to make our lives a little easier, also output @iref when
btrfs_get_extent_inline_ref_type() failed, so we can locate the item
easier.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205475
Fixes: 64ecdb647d ("Btrfs: add one more sanity check for shared ref type")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
[ update comments and messages ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-09-07 14:51:05 +02:00
arch Merge branch 'parisc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux into master 2020-07-26 12:14:46 -07:00
block
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Documentation Char/misc driver fixes for 5.8-rc7 2020-07-26 09:33:25 -07:00
drivers Char/misc driver fixes for 5.8-rc7 2020-07-26 09:33:25 -07:00
fs btrfs: require only sector size alignment for parent eb bytenr 2020-09-07 14:51:05 +02:00
include btrfs: add metadata_uuid to FS_INFO ioctl 2020-07-27 12:55:43 +02:00
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Makefile Linux 5.8-rc7 2020-07-26 14:14:06 -07:00
README

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.