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author | dwmalone <dwmalone@FreeBSD.org> | 2000-10-24 10:13:36 +0000 |
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committer | dwmalone <dwmalone@FreeBSD.org> | 2000-10-24 10:13:36 +0000 |
commit | 23aacadb399d3f3dd29eaa0a598b0359a2cd352a (patch) | |
tree | 85dc5320ff541ac0d2796e656cd50c2ebbf1bbf7 /sys/nfs/nfs_common.c | |
parent | 79719d2ea5f8674e63d2a884d88c38227a3f1e38 (diff) | |
download | FreeBSD-src-23aacadb399d3f3dd29eaa0a598b0359a2cd352a.zip FreeBSD-src-23aacadb399d3f3dd29eaa0a598b0359a2cd352a.tar.gz |
Problem to avoid processes getting stuck in "vmopar". From Ian's
mail:
The problem seems to originate with NFS's postop_attr
information that is returned with a read or write RPC.
Within a vm_fault context, the code cannot deal with
vnode_pager_setsize() shrinking a vnode.
The workaround in the patch below stops the nfsm_postop_attr()
macro from ever shrinking a vnode. If the new size in the
postop_attr information is smaller, then it just sets the
nfsnode n_attrstamp to 0 to stop the wrong size getting
used in the future. This change only affects postop_attr
attributes; the nfsm_loadattr() macro works as normal.
The change is implemented by adding a new argument to
nfs_loadattrcache() called 'dontshrink'. When this is
non-zero, nfs_loadattrcache() will never reduce the
vnode/nfsnode size; instead it zeros n_attrstamp.
There remain other was processes can get stuck in vmopar.
Submitted by: Ian Dowse <iedowse@maths.tcd.ie>
Reviewed by: dillon
Tested by: Vadim Belman <voland@lflat.org>
Diffstat (limited to 'sys/nfs/nfs_common.c')
-rw-r--r-- | sys/nfs/nfs_common.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/sys/nfs/nfs_common.c b/sys/nfs/nfs_common.c index 5934465..95f7d5b 100644 --- a/sys/nfs/nfs_common.c +++ b/sys/nfs/nfs_common.c @@ -1203,11 +1203,12 @@ nfs_uninit(vfsp) * copy the attributes to *vaper */ int -nfs_loadattrcache(vpp, mdp, dposp, vaper) +nfs_loadattrcache(vpp, mdp, dposp, vaper, dontshrink) struct vnode **vpp; struct mbuf **mdp; caddr_t *dposp; struct vattr *vaper; + int dontshrink; { register struct vnode *vp = *vpp; register struct vattr *vap; @@ -1323,9 +1324,18 @@ nfs_loadattrcache(vpp, mdp, dposp, vaper) vap->va_gen = fxdr_unsigned(u_int32_t,fp->fa2_ctime.nfsv2_usec); vap->va_filerev = 0; } + np->n_attrstamp = time_second; if (vap->va_size != np->n_size) { if (vap->va_type == VREG) { - if (np->n_flag & NMODIFIED) { + if (dontshrink && vap->va_size < np->n_size) { + /* + * We've been told not to shrink the file; + * zero np->n_attrstamp to indicate that + * the attributes are stale. + */ + vap->va_size = np->n_size; + np->n_attrstamp = 0; + } else if (np->n_flag & NMODIFIED) { if (vap->va_size < np->n_size) vap->va_size = np->n_size; else @@ -1338,7 +1348,6 @@ nfs_loadattrcache(vpp, mdp, dposp, vaper) np->n_size = vap->va_size; } } - np->n_attrstamp = time_second; if (vaper != NULL) { bcopy((caddr_t)vap, (caddr_t)vaper, sizeof(*vap)); if (np->n_flag & NCHG) { |