mainlining shenanigans
10f7f6f879
[BUG] Test case generic/475 have a very high chance (almost 100%) to hit a fs hang, where a data page will never be unlocked and hang all later operations. [CAUSE] In btrfs_do_readpage(), if we hit an error from submit_extent_page() we will try to do the cleanup for our current io range, and exit. This works fine for PAGE_SIZE == sectorsize cases, but not for subpage. For subpage btrfs_do_readpage() will lock the full page first, which can contain several different sectors and extents: btrfs_do_readpage() |- begin_page_read() | |- btrfs_subpage_start_reader(); | Now the page will have PAGE_SIZE / sectorsize reader pending, | and the page is locked. | |- end_page_read() for different branches | This function will reduce subpage readers, and when readers | reach 0, it will unlock the page. But when submit_extent_page() failed, we only cleanup the current io range, while the remaining io range will never be cleaned up, and the page remains locked forever. [FIX] Update the error handling of submit_extent_page() to cleanup all the remaining subpage range before exiting the loop. Please note that, now submit_extent_page() can only fail due to sanity check in alloc_new_bio(). Thus regular IO errors are impossible to trigger the error path. CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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.