mainlining shenanigans
603f000b15
The RTINHERIT bit can be set on a directory so that newly created regular files will have the REALTIME bit set to store their data on the realtime volume. If an extent size hint (and EXTSZINHERIT) are set on the directory, the hint will also be copied into the new file. As pointed out in previous patches, for realtime files we require the extent size hint be an integer multiple of the realtime extent, but we don't perform the same validation on a directory with both RTINHERIT and EXTSZINHERIT set, even though the only use-case of that combination is to propagate extent size hints into new realtime files. This leads to inode corruption errors when the bad values are propagated. Because there may be existing filesystems with such a configuration, we cannot simply amend the inode verifier to trip on these directories and call it a day because that will cause previously "working" filesystems to start throwing errors abruptly. Note that it's valid to have directories with rtinherit set even if there is no realtime volume, in which case the problem does not manifest because rtinherit is ignored if there's no realtime device; and it's possible that someone set the flag, crashed, repaired the filesystem (which clears the hint on the realtime file) and continued. Therefore, mitigate this issue in several ways: First, if we try to write out an inode with both rtinherit/extszinherit set and an unaligned extent size hint, turn off the hint to correct the error. Second, if someone tries to misconfigure a directory via the fssetxattr ioctl, fail the ioctl. Third, reverify both extent size hint values when we propagate heritable inode attributes from parent to child, to prevent misconfigurations from spreading. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.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.