diff options
author | jeff <jeff@FreeBSD.org> | 2006-03-31 03:52:24 +0000 |
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committer | jeff <jeff@FreeBSD.org> | 2006-03-31 03:52:24 +0000 |
commit | d018a9a82031a9c4b99602056e747592e74b6b80 (patch) | |
tree | 1dfd6abf75b0ca4f6116ac125e0ee25c0e65269e /sys | |
parent | 1a43943ef60bbb86e45d755c6d1055f7513530a5 (diff) | |
download | FreeBSD-src-d018a9a82031a9c4b99602056e747592e74b6b80.zip FreeBSD-src-d018a9a82031a9c4b99602056e747592e74b6b80.tar.gz |
- GETWRITEMOUNT now returns a referenced mountpoint to prevent its
identity from changing. This is possible now that mounts are not freed.
Discussed with: tegge
Tested by: kris
Sponsored by: Isilon Systems, Inc.
Diffstat (limited to 'sys')
-rw-r--r-- | sys/kern/vfs_default.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c index 5f43685..bf33115 100644 --- a/sys/kern/vfs_default.c +++ b/sys/kern/vfs_default.c @@ -343,8 +343,22 @@ vop_stdgetwritemount(ap) struct mount **a_mpp; } */ *ap; { + struct mount *mp; - *(ap->a_mpp) = ap->a_vp->v_mount; + /* + * XXX Since this is called unlocked we may be recycled while + * attempting to ref the mount. If this is the case or mountpoint + * will be set to NULL. We only have to prevent this call from + * returning with a ref to an incorrect mountpoint. It is not + * harmful to return with a ref to our previous mountpoint. + */ + mp = ap->a_vp->v_mount; + vfs_ref(mp); + if (mp != ap->a_vp->v_mount) { + vfs_rel(mp); + mp = NULL; + } + *(ap->a_mpp) = mp; return (0); } |