[PATCH] autofs4: add v5 follow_link mount trigger method
This patch adds a follow_link inode method for the root of an autofs direct
mount trigger. It also adds the corresponding mount options and updates the
show_mount method.
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 26eb1f0..3f00485 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -4,7 +4,7 @@
*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
* Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
- * Copyright 2001-2003 Ian Kent <raven@themaw.net>
+ * Copyright 2001-2006 Ian Kent <raven@themaw.net>
*
* This file is part of the Linux kernel and is made available under
* the terms of the GNU General Public License, version 2, or at your
@@ -30,6 +30,7 @@
static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir);
static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);
static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
+static void *autofs4_follow_link(struct dentry *, struct nameidata *);
struct file_operations autofs4_root_operations = {
.open = dcache_dir_open,
@@ -46,7 +47,7 @@
.readdir = autofs4_dir_readdir,
};
-struct inode_operations autofs4_root_inode_operations = {
+struct inode_operations autofs4_indirect_root_inode_operations = {
.lookup = autofs4_lookup,
.unlink = autofs4_dir_unlink,
.symlink = autofs4_dir_symlink,
@@ -54,6 +55,11 @@
.rmdir = autofs4_dir_rmdir,
};
+struct inode_operations autofs4_direct_root_inode_operations = {
+ .lookup = autofs4_lookup,
+ .follow_link = autofs4_follow_link,
+};
+
struct inode_operations autofs4_dir_inode_operations = {
.lookup = autofs4_lookup,
.unlink = autofs4_dir_unlink,
@@ -252,7 +258,7 @@
*/
status = d_invalidate(dentry);
if (status != -EBUSY)
- return 0;
+ return -ENOENT;
}
DPRINTK("dentry=%p %.*s ino=%p",
@@ -271,17 +277,17 @@
DPRINTK("mount done status=%d", status);
if (status && dentry->d_inode)
- return 0; /* Try to get the kernel to invalidate this dentry */
+ return status; /* Try to get the kernel to invalidate this dentry */
/* Turn this into a real negative dentry? */
if (status == -ENOENT) {
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
- return 0;
+ return status;
} else if (status) {
/* Return a negative dentry, but leave it "pending" */
- return 0;
+ return status;
}
/* Trigger mount for path component or follow link */
} else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
@@ -300,7 +306,7 @@
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
- return 0;
+ return status;
}
}
@@ -311,7 +317,41 @@
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
- return 1;
+ return status;
+}
+
+/* For autofs direct mounts the follow link triggers the mount */
+static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ int oz_mode = autofs4_oz_mode(sbi);
+ unsigned int lookup_type;
+ int status;
+
+ DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
+ dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
+ nd->flags);
+
+ /* If it's our master or we shouldn't trigger a mount we're done */
+ lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY);
+ if (oz_mode || !lookup_type)
+ goto done;
+
+ status = try_to_fill_dentry(dentry, 0);
+ if (status)
+ goto out_error;
+
+ if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {
+ status = -ENOENT;
+ goto out_error;
+ }
+
+done:
+ return NULL;
+
+out_error:
+ path_release(nd);
+ return ERR_PTR(status);
}
/*
@@ -326,13 +366,13 @@
struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
int oz_mode = autofs4_oz_mode(sbi);
int flags = nd ? nd->flags : 0;
- int status = 1;
+ int status = 0;
/* Pending dentry */
if (autofs4_ispending(dentry)) {
if (!oz_mode)
status = try_to_fill_dentry(dentry, flags);
- return status;
+ return !status;
}
/* Negative dentry.. invalidate if "old" */
@@ -349,14 +389,14 @@
spin_unlock(&dcache_lock);
if (!oz_mode)
status = try_to_fill_dentry(dentry, flags);
- return status;
+ return !status;
}
spin_unlock(&dcache_lock);
return 1;
}
-static void autofs4_dentry_release(struct dentry *de)
+void autofs4_dentry_release(struct dentry *de)
{
struct autofs_info *inf;