Rick Macklem 6bfa4ed63f MFC: r321688 ...

Add kernel support for the NFS client forced dismount "umount -N" option.

When an NFS mount is hung against an unresponsive NFS server, the "umount -f"
option can be used to dismount the mount. Unfortunately, "umount -f" gets
hung as well if a "umount" without "-f" has already been done. Usually,
this is because of a vnode lock being held by the "umount" for the mounted-on
vnode.
This patch adds kernel code so that a new "-N" option can be added to "umount",
allowing it to avoid getting hung for this case.
It adds two flags. One indicates that a forced dismount is about to happen
and the other is used, along with setting mnt_data == NULL, to handshake
with the nfs_unmount() VFS call.
It includes a slight change to the interface used between the client and
common NFS modules, so I bumped __FreeBSD_version to ensure both modules are
rebuilt.

2017-08-25 22:52:40 +00:00

..

bootp_subr.c

…

krpc_subr.c

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krpc.h

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nfs_common.h

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nfs_diskless.c

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nfs_fha.c

MFC r321794: Improve FHA locality control for NFS read/write requests.

2017-08-07 07:02:51 +00:00

nfs_fha.h

MFC r321794: Improve FHA locality control for NFS read/write requests.

2017-08-07 07:02:51 +00:00

nfs_kdtrace.h

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nfs_lock.c

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nfs_lock.h

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nfs_mountcommon.h

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nfs_nfssvc.c

MFC: r321688

2017-08-25 22:52:40 +00:00

nfsdiskless.h

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nfsproto.h

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nfssvc.h

MFC: r321688

2017-08-25 22:52:40 +00:00

xdr_subs.h

…