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3239c44df7
Currently the error handling of run_delalloc_nocow() modifies @cur_offset to handle different parts of the delalloc range. However the error handling can always be split into 3 parts: 1) The range with ordered extents allocated (OE cleanup) We have to cleanup the ordered extents and unlock the folios. 2) The range that have been cleaned up (skip) For now it's only for the range of fallback_to_cow(). We should not touch it at all. 3) The range that is not yet touched (untouched) We have to unlock the folios and clear any reserved space. This 3 ranges split has the same principle as cow_file_range(), however the NOCOW/COW handling makes the above 3 range split much more complex: a) Failure immediately after a successful OE allocation Thus no @cow_start nor @cow_end set. start cur_offset end | OE cleanup | untouched | b) Failure after hitting a COW range but before calling fallback_to_cow() start cow_start cur_offset end | OE Cleanup | untouched | c) Failure to call fallback_to_cow() start cow_start cow_end end | OE Cleanup | skip | untouched | Instead of modifying @cur_offset, do proper range calculation for OE-cleanup and untouched ranges using above 3 cases with proper range charts. This avoid updating @cur_offset, as it will an extra output for debug purposes later, and explain the behavior easier. 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 reStructuredText 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.