mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-03 14:42:18 -04:00
1c3ab6dfa0
[BUG]
During my scrub rework, I did a stupid thing like this:
bio->bi_iter.bi_sector = stripe->logical;
btrfs_submit_bio(fs_info, bio, stripe->mirror_num);
Above bi_sector assignment is using logical address directly, which
lacks ">> SECTOR_SHIFT".
This results a read on a range which has no chunk mapping.
This results the following crash:
BTRFS critical (device dm-1): unable to find logical 11274289152 length 65536
assertion failed: !IS_ERR(em), in fs/btrfs/volumes.c:6387
Sure this is all my fault, but this shows a possible problem in real
world, that some bit flip in file extents/tree block can point to
unmapped ranges, and trigger above ASSERT(), or if CONFIG_BTRFS_ASSERT
is not configured, cause invalid pointer access.
[PROBLEMS]
In the above call chain, we just don't handle the possible error from
btrfs_get_chunk_map() inside __btrfs_map_block().
[FIX]
The fix is straightforward, replace the ASSERT() with proper error
handling (callers handle errors already).
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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.