[2/2] nfsd4: Don't set DISCONNECTED on "pseudo filesystem" dentries

Commit Message

Bruce Fields July 27, 2012, 8:11 p.m. UTC

From: "J. Bruce Fields" <[e-mail]>

I can't for the life of me see any reason why anyone would care whether
a dentry that is never hooked into the dentry cache would need
DCACHE_DISCONNECTED set.

This originates from 4b936885ab04dc6e0bb0ef35e0e23c1a7364d9e5 "fs:
improve scalability of pseudo filesystems", which probably just made the
false assumption the DCACHE_DISCONNECTED was meant to be set on anything
not connected to a parent somehow.

So this is just confusing.  Ideally the only use DCACHE_DISCONNECTED
would be in the filehandle-lookup code, which needs it to ensure
dentries are connected into the dentry tree before use.

I left d_alloc_pseudo there even though it's now equivalent to
__d_alloc(), just on the theory the name is better documentation of its
intended use outside dcache.c.

Cc: Nick Piggin <[e-mail]>
Signed-off-by: J. Bruce Fields <[e-mail]>
---
 fs/dcache.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Patch

diff --git a/fs/dcache.c b/fs/dcache.c
index 740b4f5..1b1e925 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1350,12 +1350,13 @@  struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
 }
 EXPORT_SYMBOL(d_alloc);
 
+/*
+ * For filesystems that do not actually use the dentry cache at all, and
+ * only ever deal in IS_ROOT() dentries:
+ */
 struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name)
 {
-	struct dentry *dentry = __d_alloc(sb, name);
-	if (dentry)
-		dentry->d_flags |= DCACHE_DISCONNECTED;
-	return dentry;
+	return __d_alloc(sb, name);
 }
 EXPORT_SYMBOL(d_alloc_pseudo);