4a7727725d
This patch fixes a couple problems dealing with spectators who remain with gfs2 mounts after the last non-spectator node fails. Before this patch, spectator mounts would try to acquire the dlm's mounted lock EX as part of its normal recovery sequence. The mounted lock is only used to determine whether the node is the first mounter, the first node to mount the file system, for the purposes of file system recovery and journal replay. It's not necessary for spectators: they should never do journal recovery. If they acquire the lock it will prevent another "real" first-mounter from acquiring the lock in EX mode, which means it also cannot do journal recovery because it doesn't think it's the first node to mount the file system. This patch checks if the mounter is a spectator, and if so, avoids grabbing the mounted lock. This allows a secondary mounter who is really the first non-spectator mounter, to do journal recovery: since the spectator doesn't acquire the lock, it can grab it in EX mode, and therefore consider itself to be the first mounter both as a "real" first mount, and as a first-real-after-spectator. Note that the control lock still needs to be taken in PR mode in order to fetch the lvb value so it has the current status of all journal's recovery. This is used as it is today by a first mounter to replay the journals. For spectators, it's merely used to fetch the status bits. All recovery is bypassed and the node waits until recovery is completed by a non-spectator node. I also improved the cryptic message given by control_mount when a spectator is waiting for a non-spectator to perform recovery. It also fixes a problem in gfs2_recover_set whereby spectators were never queueing recovery work for their own journal. They cannot do recovery themselves, but they still need to queue the work so they can check the recovery bits and clear the DFL_BLOCK_LOCKS bit once the recovery happens on another node. When the work queue runs on a spectator, it bypasses most of the work so it won't print a bunch of annoying messages. All it will print is a bunch of messages that look like this until recovery completes on the non-spectator node: GFS2: fsid=mycluster:scratch.s: recover generation 3 jid 0 GFS2: fsid=mycluster:scratch.s: recover jid 0 result busy These continue every 1.5 seconds until the recovery is done by the non-spectator, at which time it says: GFS2: fsid=mycluster:scratch.s: recover generation 4 done Then it proceeds with its mount. If the file system is mounted in spectator node and the last remaining non-spectator is fenced, any IO to the file system is blocked by dlm and the spectator waits until recovery is performed by a non-spectator. If a spectator tries to mount the file system before any non-spectators, it blocks and repeatedly gives this kernel message: GFS2: fsid=mycluster:scratch: Recovery is required. Waiting for a non-spectator to mount. GFS2: fsid=mycluster:scratch: Recovery is required. Waiting for a non-spectator to mount. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> |
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| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| 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 | ||
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.