3466958beb
In fuse when a direct/write-through write happens we invalidate attrs because that might have updated mtime/ctime on server and cached mtime/ctime will be stale. What about page writeback path. Looks like we don't invalidate attrs there. To be consistent, invalidate attrs in writeback path as well. Only exception is when writeback_cache is enabled. In that case we strust local mtime/ctime and there is no need to invalidate attrs. Recently users started experiencing failure of xfstests generic/080, geneirc/215 and generic/614 on virtiofs. This happened only newer "stat" utility and not older one. This patch fixes the issue. So what's the root cause of the issue. Here is detailed explanation. generic/080 test does mmap write to a file, closes the file and then checks if mtime has been updated or not. When file is closed, it leads to flushing of dirty pages (and that should update mtime/ctime on server). But we did not explicitly invalidate attrs after writeback finished. Still generic/080 passed so far and reason being that we invalidated atime in fuse_readpages_end(). This is called in fuse_readahead() path and always seems to trigger before mmaped write. So after mmaped write when lstat() is called, it sees that atleast one of the fields being asked for is invalid (atime) and that results in generating GETATTR to server and mtime/ctime also get updated and test passes. But newer /usr/bin/stat seems to have moved to using statx() syscall now (instead of using lstat()). And statx() allows it to query only ctime or mtime (and not rest of the basic stat fields). That means when querying for mtime, fuse_update_get_attr() sees that mtime is not invalid (only atime is invalid). So it does not generate a new GETATTR and fill stat with cached mtime/ctime. And that means updated mtime is not seen by xfstest and tests start failing. Invalidating attrs after writeback completion should solve this problem in a generic manner. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> |
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| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
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| COPYING | ||
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| Kbuild | ||
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| README | ||
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.