4cda7f7ece
- Suspend filesystem for unmount. This prevents new tmpfs nodes from instantiating, and also ensures that only unmount thread can destroy nodes. - Do not start tmpfs node deletion until all vnodes are reclaimed, which guarantees that no thread can access tmpfs data. For this, call vflush() in the loop, until the mnt_nvnodelistsize is non-zero. Note that after mnt_nvnodelistsize becomes 0, insmntque() blocks insertion of a vnode germ into the mount list of vnodes. - Fail node allocation when the filesystem is being unmounted. This is race-free due to the vflush() call in loop. This is mostly cosmetic, avoiding some more work which might be done until suspension in unmount is started. Note that there is currently no way to prevent new vnode instantiation from readers during the unmount. Due to this, forced unmount might live-lock if vflush() loop cannot get to the zero vnode count due to races with readers. The unmount would proceed after the load is lifted. Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks |
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| .. | ||
| tmpfs_fifoops.c | ||
| tmpfs_fifoops.h | ||
| tmpfs_subr.c | ||
| tmpfs_vfsops.c | ||
| tmpfs_vnops.c | ||
| tmpfs_vnops.h | ||
| tmpfs.h | ||