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a700ca5ec4
If we still go the old page based iterator functions, like
bio_for_each_segment_all(), we can hit middle pages of a folio (compound
page).
In that case if we set any page flag on those middle pages, we can
easily trigger VM_BUG_ON(), as for compound page flags, they should
follow their flag policies (normally only set on leading or tail pages).
To avoid such problem in the future full folio migration, here we do:
- Change from bio_for_each_segment_all() to bio_for_each_folio_all()
This completely removes the ability to access the middle page.
- Add extra ASSERT()s for data read/write paths
To ensure we only get single paged folio for data now.
- Rename those end io functions to follow a certain schema
* end_bbio_compressed_read()
* end_bbio_compressed_write()
These two endio functions don't set any page flags, as they use pages
not mapped to any address space.
They can be very good candidates for higher order folio testing.
And they are shared between compression and encoded IO.
* end_bbio_data_read()
* end_bbio_data_write()
* end_bbio_meta_read()
* end_bbio_meta_write()
The old function names are not unified:
- end_bio_extent_writepage()
- end_bio_extent_readpage()
- extent_buffer_write_end_io()
- extent_buffer_read_end_io()
They share no schema on where the "end_*io" string should be, nor can
be confusing just using "extent_buffer" and "extent" to distinguish
data and metadata paths.
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.