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Qu Wenruo
b7f9945a14
[BUG]
Smatch reports the following errors related to commit ("btrfs: output
affected files when relocation fails"):
fs/btrfs/inode.c:283 print_data_reloc_error()
error: uninitialized symbol 'ref_level'.
[CAUSE]
That part of code is mostly copied from scrub, but unfortunately scrub
code from the beginning is not doing the error handling properly.
The offending code looks like this:
do {
ret = tree_backref_for_extent();
btrfs_warn_rl();
} while (ret != 1);
There are several problems involved:
- No error handling
If that tree_backref_for_extent() failed, we would output the same
error again and again, never really exit as it requires ret == 1 to
exit.
- Always do one extra output
As tree_backref_for_extent() only return > 0 if there is no more
backref item.
This means after the last item we hit, we would output an invalid
error message for ret > 0 case.
[FIX]
Fix the old code by:
- Move @ref_root and @ref_level into the if branch
And do not initialize them, so we can catch such uninitialized values
just like what we do in the inode.c
- Explicitly check the return value of tree_backref_for_extent()
And handle ret < 0 and ret > 0 cases properly.
- No more do {} while () loop
Instead go while (true) {} loop since we will handle @ret manually.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@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.