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| author | iedowse <iedowse@FreeBSD.org> | 2002-04-17 01:07:29 +0000 |
|---|---|---|
| committer | iedowse <iedowse@FreeBSD.org> | 2002-04-17 01:07:29 +0000 |
| commit | 64322dabea69a0542951fed96cb8bb7c81602b56 (patch) | |
| tree | fd4db1996177f18b62183e61df1a1e3dae92eb51 /sys/kern | |
| parent | 366464c33c243b21ec0040bc08c326d02b8630a9 (diff) | |
| download | FreeBSD-src-64322dabea69a0542951fed96cb8bb7c81602b56.zip FreeBSD-src-64322dabea69a0542951fed96cb8bb7c81602b56.tar.gz | |
The recent NFS forced unmount improvements introduced a side-effect
where some client operations might be unexpectedly cancelled during
an unsuccessful non-forced unmount attempt. This causes problems
for amd(8), because it periodically attempts a non-forced unmount
to check if the filesystem is still in use.
Fix this by adding a new mountpoint flag MNTK_UNMOUNTF that is set
only during the operation of a forced unmount. Use this instead of
MNTK_UNMOUNT to trigger the cancellation of hung NFS operations.
Also correct a problem where dounmount() might inadvertently clear
the MNTK_UNMOUNT flag.
Reported by: simokawa
MFC after: 1 week
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/vfs_extattr.c | 11 | ||||
| -rw-r--r-- | sys/kern/vfs_syscalls.c | 11 |
2 files changed, 18 insertions, 4 deletions
diff --git a/sys/kern/vfs_extattr.c b/sys/kern/vfs_extattr.c index 157f6be..68b392a 100644 --- a/sys/kern/vfs_extattr.c +++ b/sys/kern/vfs_extattr.c @@ -1103,11 +1103,18 @@ dounmount(mp, flags, td) int async_flag; mtx_lock(&mountlist_mtx); + if (mp->mnt_kern_flag & MNTK_UNMOUNT) { + mtx_unlock(&mountlist_mtx); + return (EBUSY); + } mp->mnt_kern_flag |= MNTK_UNMOUNT; + /* Allow filesystems to detect that a forced unmount is in progress. */ + if (flags & MNT_FORCE) + mp->mnt_kern_flag |= MNTK_UNMOUNTF; error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), &mountlist_mtx, td); if (error) { - mp->mnt_kern_flag &= ~MNTK_UNMOUNT; + mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); if (mp->mnt_kern_flag & MNTK_MWAIT) wakeup((caddr_t)mp); return (error); @@ -1153,7 +1160,7 @@ dounmount(mp, flags, td) if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) (void) vfs_allocate_syncvnode(mp); mtx_lock(&mountlist_mtx); - mp->mnt_kern_flag &= ~MNTK_UNMOUNT; + mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); mp->mnt_flag |= async_flag; lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, &mountlist_mtx, td); diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c index 157f6be..68b392a 100644 --- a/sys/kern/vfs_syscalls.c +++ b/sys/kern/vfs_syscalls.c @@ -1103,11 +1103,18 @@ dounmount(mp, flags, td) int async_flag; mtx_lock(&mountlist_mtx); + if (mp->mnt_kern_flag & MNTK_UNMOUNT) { + mtx_unlock(&mountlist_mtx); + return (EBUSY); + } mp->mnt_kern_flag |= MNTK_UNMOUNT; + /* Allow filesystems to detect that a forced unmount is in progress. */ + if (flags & MNT_FORCE) + mp->mnt_kern_flag |= MNTK_UNMOUNTF; error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), &mountlist_mtx, td); if (error) { - mp->mnt_kern_flag &= ~MNTK_UNMOUNT; + mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); if (mp->mnt_kern_flag & MNTK_MWAIT) wakeup((caddr_t)mp); return (error); @@ -1153,7 +1160,7 @@ dounmount(mp, flags, td) if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) (void) vfs_allocate_syncvnode(mp); mtx_lock(&mountlist_mtx); - mp->mnt_kern_flag &= ~MNTK_UNMOUNT; + mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); mp->mnt_flag |= async_flag; lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, &mountlist_mtx, td); |
