| Message ID | 20120712224008.GF24162@fieldses.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jul 12, 2012 at 06:40:08PM -0400, J. Bruce Fields wrote: > On Thu, Jul 12, 2012 at 06:28:49PM -0400, bfields wrote: > > I've been trying to figure out if we can pare down DCACHE_DISCONNECTED > > uses to only those required by exportfs, and ran across this one. > > There's also one DCACHE_DISCONNECTED use in fs/nfs/dir.c that I was > hoping could be eliminated. It was added by Al with > d9e80b7de91db05c1c4d2e5ebbfd70b3b3ba0e0f. It looks totally theoretical > to me (nfs isn't exportable, hence shouldn't see DCACHE_DISCONNECTED > dentries), but maybe I'm missing something. Ignore me, I'm confused: there's a different use of DCACHE_DISCONECTED here (for v2/v3 root dentries that we expect may one day be hooked into a parent we find someplace else?). It looks to me like it clashes with nfsd/exportfs's use. I'm not sure what to do about that. --b. > > At a minimum maybe we could pull a comment out of Al's commit?: > > --b. > > diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c > index f430057..b96c687 100644 > --- a/fs/nfs/dir.c > +++ b/fs/nfs/dir.c > @@ -1194,6 +1194,12 @@ out_zap_parent: > /* If we have submounts, don't unhash ! */ > if (have_submounts(dentry)) > goto out_valid; > + /* > + * We can't d_drop the root of a disconnected tree: > + * its d_hash is on the s_anon list and d_drop() would hide > + * it from shrink_dcache_for_unmount(), leading to busy > + * inodes on unmount and further oopses. > + */ > if (dentry->d_flags & DCACHE_DISCONNECTED) > goto out_valid; > shrink_dcache_parent(dentry); > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index f430057..b96c687 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1194,6 +1194,12 @@ out_zap_parent: /* If we have submounts, don't unhash ! */ if (have_submounts(dentry)) goto out_valid; + /* + * We can't d_drop the root of a disconnected tree: + * its d_hash is on the s_anon list and d_drop() would hide + * it from shrink_dcache_for_unmount(), leading to busy + * inodes on unmount and further oopses. + */ if (dentry->d_flags & DCACHE_DISCONNECTED) goto out_valid; shrink_dcache_parent(dentry);