fs: no games with DCACHE_UNHASHED

Filesystems outside the regular namespace do not have to clear DCACHE_UNHASHED
in order to have a working /proc/$pid/fd/XXX. Nothing in proc prevents the
fd link from being used if its dentry is not in the hash.

Also, it does not get put into the dcache hash if DCACHE_UNHASHED is clear;
that depends on the filesystem calling d_add or d_rehash.

So delete the misleading comments and needless code.

Acked-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 0 insertions, 18 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index 43d79da5c57e..37ba29ff3158 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -906,17 +906,6 @@ void free_pipe_info(struct inode *inode)
 }
 
 static struct vfsmount *pipe_mnt __read_mostly;
-static int pipefs_delete_dentry(struct dentry *dentry)
-{
-        /*
-         * At creation time, we pretended this dentry was hashed
-         * (by clearing DCACHE_UNHASHED bit in d_flags)
-         * At delete time, we restore the truth : not hashed.
-         * (so that dput() can proceed correctly)
-         */
-        dentry->d_flags |= DCACHE_UNHASHED;
-        return 0;
-}
 
 /*
  * pipefs_dname() is called from d_path().
@@ -928,7 +917,6 @@ static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen)
 }
 
 static const struct dentry_operations pipefs_dentry_operations = {
-        .d_delete       = pipefs_delete_dentry,
         .d_dname        = pipefs_dname,
 };
 
@@ -989,12 +977,6 @@ struct file *create_write_pipe(int flags)
         path.mnt = mntget(pipe_mnt);
 
         path.dentry->d_op = &pipefs_dentry_operations;
-        /*
-         * We dont want to publish this dentry into global dentry hash table.
-         * We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED
-         * This permits a working /proc/$pid/fd/XXX on pipes
-         */
-        path.dentry->d_flags &= ~DCACHE_UNHASHED;
         d_instantiate(path.dentry, inode);
 
         err = -ENFILE;