On Mon, Jan 23, 2012 at 06:54:49AM -0800, John Baldwin wrote: > On 1/22/12 7:05 PM, Kostik Belousov wrote: > > On Mon, Jan 23, 2012 at 05:36:42AM +0400, Yuri Pankov wrote: > >> Seems to be reproducible here running r230467 as the NFS client and > >> r230135 as NFS server. NFSv4 not enabled. > >> > >> # mount > >> [...] > >> sirius:/data/distfiles on /usr/ports/distfiles (nfs) > >> > >> # /usr/bin/env /usr/bin/fetch -AFpr -S 4682084 -o /usr/ports/distfiles/sqlite-src-3071000.zip http://www.sqlite.org/sqlite-src-3071000.zip > >> /usr/ports/distfiles/sqlite-src-3071000.zip 100% of 4572 kB 379 kBps 00m00s > >> # rm /usr/ports/distfiles/sqlite-src-3071000.zip > >> > >> immediately followed by: > >> > >> panic: No NCF_TS > >> cpuid = 2 > >> KDB: enter: panic > >> [ thread pid 1603 tid 100494 ] > >> Stopped at kdb_enter+0x3e: movq $0,kdb_why > >> db> bt > >> Tracing pid 1603 tid 100494 td 0xfffffe0089585460 > >> kdb_enter() at kdb_enter+0x3e > >> panic() at panic+0x245 > >> cache_lookup_times() at cache_lookup_times+0x6b5 > >> nfs_lookup() at nfs_lookup+0x190 > >> VOP_LOOKUP_APV() at VOP_LOOKUP_APV+0x8b > >> lookup() at lookup+0x7e9 > >> namei() at namei+0x74c > >> kern_statat_vnhook() at kern_statat_vnhook+0x90 > >> sys_lstat() at sys_lstat+0x30 > >> amd64_syscall() at amd64_syscall+0x221 > >> Xfast_syscall() at Xfast_syscall+0xfb > >> --- syscall (190, FreeBSD ELF64, sys_lstat), rip = 0x80093ff3c, rsp = 0x7fffffffd8d8, rbp = 0x7fffffffd979 --- > >> > > > > Yes, my bad. I wrote the r230441 with the assumption that filesystems > > are consistent in their use of cache_enter_time(). And my net-booting > > test box did not catched this, which is at least interesting. > > > > Please try the change below. Actually, it should be enough to only apply > > the changes for fs/nfsclient (or nfsclient/ if you use old nfs). If this > > does not help, then please try the whole patch. > > I think we should have the existing assertion. If cache_lookup_times() > is called with a timestamp requested, then returning a name cache entry > without a timestamp is just going to result in that name cache entry not > being used. Panic'ing in that case is correct. > > With regard to the NFS changes below, all of these are bugs that didn't > really work right before. Specifically, adding a positive entry without > setting n_ctime previously would have just resulted in the name cache > entry being purged on the next lookup anyway. Keep in mind that the > timestamp for a give name cache entry in NFS needs to match an actual > timestamp returned by the NFS server as post-op attributes in some RPC. > Using the timestamp from vfs_timestamp() is completely bogus. Instead, > the timestamp for a negative entry needs to be the mtime of the parent > directory. If we don't have that timestamp handy, then we should just > not add a namecache entry at all. Also, the vap->va_ctime used below > for mknod() and create() is not a timestamp from the server, so it is > also suspect. I can look at this in more detail on Wednesday, but my > best guess is that nearly all (if not all) of these cache_enter() calls > will simply need to be removed. > > Note that other filesystems like UFS don't bother creating name cache > entries for things like create or mknod. It's debatable if the NFS > client should even be creating any name cache entries outside of lookup > and when handling a READDIR+ reply. Ok, next try. I did removed the cache_enter calls for old nfs client, but it seems that the calls can be kept for the new client. diff --git a/sys/fs/nfsclient/nfs_clvnops.c b/sys/fs/nfsclient/nfs_clvnops.c index 2747191..709cd8d 100644 --- a/sys/fs/nfsclient/nfs_clvnops.c +++ b/sys/fs/nfsclient/nfs_clvnops.c _at__at_ -1431,8 +1431,6 _at__at_ nfs_mknodrpc(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, } } if (!error) { - if ((cnp->cn_flags & MAKEENTRY)) - cache_enter(dvp, newvp, cnp); *vpp = newvp; } else if (NFS_ISV4(dvp)) { error = nfscl_maperr(cnp->cn_thread, error, vap->va_uid, _at__at_ -1591,7 +1589,7 _at__at_ again: } if (!error) { if (cnp->cn_flags & MAKEENTRY) - cache_enter(dvp, newvp, cnp); + cache_enter_time(dvp, newvp, cnp, &vap->va_ctime); *ap->a_vpp = newvp; } else if (NFS_ISV4(dvp)) { error = nfscl_maperr(cnp->cn_thread, error, vap->va_uid, _at__at_ -1966,8 +1964,9 _at__at_ nfs_link(struct vop_link_args *ap) * must care about lookup caching hit rate, so... */ if (VFSTONFS(vp->v_mount)->nm_negnametimeo != 0 && - (cnp->cn_flags & MAKEENTRY)) - cache_enter(tdvp, vp, cnp); + (cnp->cn_flags & MAKEENTRY) && dattrflag) { + cache_enter_time(tdvp, vp, cnp, &dnfsva.na_mtime); + } if (error && NFS_ISV4(vp)) error = nfscl_maperr(cnp->cn_thread, error, (uid_t)0, (gid_t)0); _at__at_ -2023,15 +2022,6 _at__at_ nfs_symlink(struct vop_symlink_args *ap) error = nfscl_maperr(cnp->cn_thread, error, vap->va_uid, vap->va_gid); } else { - /* - * If negative lookup caching is enabled, I might as well - * add an entry for this node. Not necessary for correctness, - * but if negative caching is enabled, then the system - * must care about lookup caching hit rate, so... - */ - if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 && - (cnp->cn_flags & MAKEENTRY)) - cache_enter(dvp, newvp, cnp); *ap->a_vpp = newvp; } _at__at_ -2041,6 +2031,16 _at__at_ nfs_symlink(struct vop_symlink_args *ap) if (dattrflag != 0) { mtx_unlock(&dnp->n_mtx); (void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1); + /* + * If negative lookup caching is enabled, I might as well + * add an entry for this node. Not necessary for correctness, + * but if negative caching is enabled, then the system + * must care about lookup caching hit rate, so... + */ + if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 && + (cnp->cn_flags & MAKEENTRY)) { + cache_enter_time(dvp, newvp, cnp, &dnfsva.na_mtime); + } } else { dnp->n_attrstamp = 0; mtx_unlock(&dnp->n_mtx); _at__at_ -2116,8 +2116,9 _at__at_ nfs_mkdir(struct vop_mkdir_args *ap) * must care about lookup caching hit rate, so... */ if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 && - (cnp->cn_flags & MAKEENTRY)) - cache_enter(dvp, newvp, cnp); + (cnp->cn_flags & MAKEENTRY) && dattrflag) { + cache_enter_time(dvp, newvp, cnp, &dnfsva.na_mtime); + } *ap->a_vpp = newvp; } return (error); diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index 647dcac..4562ebc 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c _at__at_ -237,13 +237,9 _at__at_ static void cache_out_ts(struct namecache *ncp, struct timespec *tsp, int *ticksp) { - if ((ncp->nc_flag & NCF_TS) == 0) { - if (tsp != NULL) - bzero(tsp, sizeof(*tsp)); - if (ticksp != NULL) - *ticksp = 0; - return; - } + KASSERT((ncp->nc_flag & NCF_TS) != 0 || + (tsp == NULL && ticksp == NULL), + ("No NCF_TS")); if (tsp != NULL) *tsp = ((struct namecache_ts *)ncp)->nc_time; _at__at_ -791,8 +787,8 _at__at_ cache_enter_time(dvp, vp, cnp, tsp) n2->nc_nlen == cnp->cn_namelen && !bcmp(nc_get_name(n2), cnp->cn_nameptr, n2->nc_nlen)) { if (tsp != NULL) { - if ((n2->nc_flag & NCF_TS) == 0) - continue; + KASSERT((n2->nc_flag & NCF_TS) != 0, + ("no NCF_TS")); n3 = (struct namecache_ts *)n2; n3->nc_time = ((struct namecache_ts *)ncp)->nc_time; diff --git a/sys/nfsclient/nfs_vnops.c b/sys/nfsclient/nfs_vnops.c index a39b29b..c2dfd97 100644 --- a/sys/nfsclient/nfs_vnops.c +++ b/sys/nfsclient/nfs_vnops.c _at__at_ -1530,8 +1530,6 _at__at_ nfsmout: if (newvp) vput(newvp); } else { - if (cnp->cn_flags & MAKEENTRY) - cache_enter(dvp, newvp, cnp); *vpp = newvp; } mtx_lock(&(VTONFS(dvp))->n_mtx); _at__at_ -1670,8 +1668,6 _at__at_ nfsmout: vput(newvp); } if (!error) { - if (cnp->cn_flags & MAKEENTRY) - cache_enter(dvp, newvp, cnp); *ap->a_vpp = newvp; } mtx_lock(&(VTONFS(dvp))->n_mtx);
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