Yesterday you passed on a report of this printk from nfsdfh.c firing:
printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
dentry);
I think the dentry probably comes from the FILEID_ROOT case of:
if (fileid_type == FILEID_ROOT)
dentry = dget(exp->ex_path.dentry);
else {
dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
data_left, fileid_type,
nfsd_acceptable, exp);
}
In that case the dentry was found using ordinary filesystem lookups, so
doesn't go through the same DISCONNECTED-clearing logic as in the case
of lookups by filehandle.
Probably they have an export root that's not a filesystem root, and the
lookups happened in the right order?
I suspect that's fine, and that the printk is just stupid, but maybe we
should clear DISCONNECTED when possible on normal lookups. The
following is my attempt, though I'm not sure if d_alloc is the right
place to do this. In any case it might help confirm this is what's
happening.
So if you pass along this patch to the person who was seeing that printk
I'd be interested in the results.
--b.
commit 49fc5637ca951d2add808a695768512f8b5bd7ad
Author: J. Bruce Fields <bfields@xxxxxxxxxx>
Date: Thu Feb 13 14:04:43 2014 -0500
dcache: clear DCACHE_DISCONNECTED on child when cleared on parent
Currently DCACHE_DISCONNECTED is only cleared by the filehandle lookup
code. That's OK, it's only the filehandle code that really cares about
this flag. But it might be kinder to also clear DCACHE_DISCONNECTED on
regular lookups when we notice it's appropriate.
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
diff --git a/fs/dcache.c b/fs/dcache.c
index 265e0ce..c4a9478 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1534,6 +1534,16 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
return dentry;
}
+static void d_inherit_connected(struct dentry *dentry)
+{
+ /*
+ * If the parent is connected, then the child is too. (But if
+ * DISCONNECTED is set, that doesn't tell us anything certain.)
+ */
+ if (!(dentry->d_parent->d_flags & DCACHE_DISCONNECTED))
+ dentry->d_flags &= ~DCACHE_DISCONNECTED;
+}
+
/**
* d_alloc - allocate a dcache entry
* @parent: parent of entry to allocate
@@ -1556,6 +1566,7 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
*/
__dget_dlock(parent);
dentry->d_parent = parent;
+ d_inherit_connected(dentry);
list_add(&dentry->d_u.d_child, &parent->d_subdirs);
spin_unlock(&parent->d_lock);
--
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