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-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZQsZLQAKCRCRxhvAZXjc op0vAP96hkSUnmXmxTr8GHId3yfElN8ZZ3aSfePeBdljjKEZVAEA2+cbHLy4GqRi TpjP1HNIdmtbVSC2ZnrgqkbwGageQgg= =s92y -----END PGP SIGNATURE----- Merge tag 'v6.6-rc3.vfs.ctime.revert' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull finegrained timestamp reverts from Christian Brauner: "Earlier this week we sent a few minor fixes for the multi-grained timestamp work in [1]. While we were polishing those up after Linus realized that there might be a nicer way to fix them we received a regression report in [2] that fine grained timestamps break gnulib tests and thus possibly other tools. The kernel will elide fine-grain timestamp updates when no one is actively querying for them to avoid performance impacts. So a sequence like write(f1) stat(f2) write(f2) stat(f2) write(f1) stat(f1) may result in timestamp f1 to be older than the final f2 timestamp even though f1 was last written too but the second write didn't update the timestamp. Such plotholes can lead to subtle bugs when programs compare timestamps. For example, the nap() function in [2] will estimate that it needs to wait one ns on a fine-grain timestamp enabled filesytem between subsequent calls to observe a timestamp change. But in general we don't update timestamps with more than one jiffie if we think that no one is actively querying for fine-grain timestamps to avoid performance impacts. While discussing various fixes the decision was to go back to the drawing board and ultimately to explore a solution that involves only exposing such fine-grained timestamps to nfs internally and never to userspace. As there are multiple solutions discussed the honest thing to do here is not to fix this up or disable it but to cleanly revert. The general infrastructure will probably come back but there is no reason to keep this code in mainline. The general changes to timestamp handling are valid and a good cleanup that will stay. The revert is fully bisectable" Link: https://lore.kernel.org/all/20230918-hirte-neuzugang-4c2324e7bae3@brauner [1] Link: https://lore.kernel.org/all/bf0524debb976627693e12ad23690094e4514303.camel@linuxfromscratch.org [2] * tag 'v6.6-rc3.vfs.ctime.revert' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: Revert "fs: add infrastructure for multigrain timestamps" Revert "btrfs: convert to multigrain timestamps" Revert "ext4: switch to multigrain timestamps" Revert "xfs: switch to multigrain timestamps" Revert "tmpfs: add support for multigrain timestamps" |
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| certs | ||
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| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| 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.