36ba360558
VOPs like VOP_SETATTR can change a file's size, with the vnode
exclusively locked. But VOPs like VOP_LOOKUP look up the file size from
the server without the vnode locked. So a race is possible. For
example:
1) One thread calls VOP_SETATTR to truncate a file. It locks the vnode
and sends FUSE_SETATTR to the server.
2) A second thread calls VOP_LOOKUP and fetches the file's attributes from
the server. Then it blocks trying to acquire the vnode lock.
3) FUSE_SETATTR returns and the first thread releases the vnode lock.
4) The second thread acquires the vnode lock and caches the file's
attributes, which are now out-of-date.
Fix this race by recording a timestamp in the vnode of the last time
that its filesize was modified. Check that timestamp during VOP_LOOKUP
and VFS_VGET. If it's newer than the time at which FUSE_LOOKUP was
issued to the server, ignore the attributes returned by FUSE_LOOKUP.
PR: 259071
Reported by: Agata <chogata@moosefs.pro>
Reviewed by: pfg
Differential Revision: https://reviews.freebsd.org/D33158
(cherry picked from commit
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| .cirrus-ci | ||
| .github/workflows | ||
| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| stand | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| .cirrus.yml | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| Makefile.sys.inc | ||
| ObsoleteFiles.inc | ||
| README | ||
| README.md | ||
| RELNOTES | ||
| UPDATING | ||
FreeBSD Source:
This is the top level of the FreeBSD source directory. This file
was last revised on:
FreeBSD
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
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include System include files.
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