From 34ca959cfc15cf09ad4da4f31ab034691e51af78 Mon Sep 17 00:00:00 2001 From: Ian Kent Date: Mon, 27 Mar 2006 01:14:54 -0800 Subject: [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 Cc: Al Viro Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/autofs4/root.c | 64 ++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 52 insertions(+), 12 deletions(-) (limited to 'fs/autofs4/root.c') diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 26eb1f02486..3f004858224 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 - * Copyright 2001-2003 Ian Kent + * Copyright 2001-2006 Ian Kent * * 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_close(struct inode *inode, struct file *file); 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 @@ struct file_operations autofs4_dir_operations = { .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 @@ struct inode_operations autofs4_root_inode_operations = { .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 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) */ status = d_invalidate(dentry); if (status != -EBUSY) - return 0; + return -ENOENT; } DPRINTK("dentry=%p %.*s ino=%p", @@ -271,17 +277,17 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) 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 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; spin_unlock(&dentry->d_lock); - return 0; + return status; } } @@ -311,7 +317,41 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) 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 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) 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 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) 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; -- cgit v1.2.3