[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>
This commit is contained in:
Ian Kent
Linus Torvalds
parent
051d381259
commit
34ca959cfc
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@ -3,6 +3,7 @@
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* linux/fs/autofs/autofs_i.h
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*
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* Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
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* Copyright 2005-2006 Ian Kent <raven@themaw.net>
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*
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* This file is part of the Linux kernel and is made available under
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* the terms of the GNU General Public License, version 2, or at your
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@ -84,6 +85,10 @@ struct autofs_wait_queue {
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#define AUTOFS_SBI_MAGIC 0x6d4a556d
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#define AUTOFS_TYP_INDIRECT 0x0001
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#define AUTOFS_TYP_DIRECT 0x0002
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#define AUTOFS_TYP_OFFSET 0x0004
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struct autofs_sb_info {
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u32 magic;
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struct dentry *root;
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@ -96,6 +101,7 @@ struct autofs_sb_info {
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int min_proto;
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int max_proto;
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unsigned long exp_timeout;
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unsigned int type;
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int reghost_enabled;
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int needs_reghost;
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struct super_block *sb;
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@ -162,6 +168,8 @@ int autofs4_expire_multi(struct super_block *, struct vfsmount *,
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extern struct inode_operations autofs4_symlink_inode_operations;
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extern struct inode_operations autofs4_dir_inode_operations;
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extern struct inode_operations autofs4_root_inode_operations;
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extern struct inode_operations autofs4_indirect_root_inode_operations;
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extern struct inode_operations autofs4_direct_root_inode_operations;
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extern struct file_operations autofs4_dir_operations;
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extern struct file_operations autofs4_root_operations;
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@ -3,6 +3,7 @@
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* linux/fs/autofs/inode.c
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*
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* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
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* Copyright 2005-2006 Ian Kent <raven@themaw.net>
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*
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* This file is part of the Linux kernel and is made available under
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* the terms of the GNU General Public License, version 2, or at your
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@ -177,6 +178,13 @@ static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
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seq_printf(m, ",minproto=%d", sbi->min_proto);
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seq_printf(m, ",maxproto=%d", sbi->max_proto);
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if (sbi->type & AUTOFS_TYP_OFFSET)
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seq_printf(m, ",offset");
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else if (sbi->type & AUTOFS_TYP_DIRECT)
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seq_printf(m, ",direct");
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else
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seq_printf(m, ",indirect");
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return 0;
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}
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@ -186,7 +194,8 @@ static struct super_operations autofs4_sops = {
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.show_options = autofs4_show_options,
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};
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enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};
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enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
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Opt_indirect, Opt_direct, Opt_offset};
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static match_table_t tokens = {
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{Opt_fd, "fd=%u"},
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@ -195,11 +204,15 @@ static match_table_t tokens = {
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{Opt_pgrp, "pgrp=%u"},
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{Opt_minproto, "minproto=%u"},
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{Opt_maxproto, "maxproto=%u"},
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{Opt_indirect, "indirect"},
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{Opt_direct, "direct"},
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{Opt_offset, "offset"},
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{Opt_err, NULL}
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};
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static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
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pid_t *pgrp, int *minproto, int *maxproto)
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pid_t *pgrp, unsigned int *type,
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int *minproto, int *maxproto)
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{
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char *p;
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substring_t args[MAX_OPT_ARGS];
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@ -253,6 +266,15 @@ static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
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return 1;
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*maxproto = option;
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break;
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case Opt_indirect:
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*type = AUTOFS_TYP_INDIRECT;
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break;
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case Opt_direct:
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*type = AUTOFS_TYP_DIRECT;
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break;
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case Opt_offset:
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*type = AUTOFS_TYP_DIRECT | AUTOFS_TYP_OFFSET;
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break;
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default:
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return 1;
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}
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@ -271,6 +293,11 @@ static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
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return ino;
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}
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void autofs4_dentry_release(struct dentry *);
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static struct dentry_operations autofs4_sb_dentry_operations = {
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.d_release = autofs4_dentry_release,
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};
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int autofs4_fill_super(struct super_block *s, void *data, int silent)
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{
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struct inode * root_inode;
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@ -297,6 +324,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
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sbi->sb = s;
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sbi->version = 0;
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sbi->sub_version = 0;
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sbi->type = 0;
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sbi->min_proto = 0;
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sbi->max_proto = 0;
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mutex_init(&sbi->wq_mutex);
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@ -315,27 +343,31 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
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if (!ino)
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goto fail_free;
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root_inode = autofs4_get_inode(s, ino);
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kfree(ino);
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if (!root_inode)
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goto fail_free;
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goto fail_ino;
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root_inode->i_op = &autofs4_root_inode_operations;
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root_inode->i_fop = &autofs4_root_operations;
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root = d_alloc_root(root_inode);
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pipe = NULL;
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if (!root)
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goto fail_iput;
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pipe = NULL;
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root->d_op = &autofs4_sb_dentry_operations;
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root->d_fsdata = ino;
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/* Can this call block? */
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if (parse_options(data, &pipefd,
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&root_inode->i_uid, &root_inode->i_gid,
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&sbi->oz_pgrp,
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&sbi->oz_pgrp, &sbi->type,
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&sbi->min_proto, &sbi->max_proto)) {
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printk("autofs: called with bogus options\n");
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goto fail_dput;
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}
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root_inode->i_fop = &autofs4_root_operations;
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root_inode->i_op = sbi->type & AUTOFS_TYP_DIRECT ?
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&autofs4_direct_root_inode_operations :
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&autofs4_indirect_root_inode_operations;
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/* Couldn't this be tested earlier? */
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if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
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sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
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@ -391,6 +423,8 @@ fail_dput:
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fail_iput:
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printk("autofs: get root dentry failed\n");
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iput(root_inode);
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fail_ino:
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kfree(ino);
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fail_free:
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kfree(sbi);
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fail_unlock:
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@ -4,7 +4,7 @@
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*
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* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
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* Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
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* Copyright 2001-2003 Ian Kent <raven@themaw.net>
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* Copyright 2001-2006 Ian Kent <raven@themaw.net>
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*
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* This file is part of the Linux kernel and is made available under
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* the terms of the GNU General Public License, version 2, or at your
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@ -30,6 +30,7 @@ static int autofs4_dir_close(struct inode *inode, struct file *file);
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static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir);
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static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);
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static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
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static void *autofs4_follow_link(struct dentry *, struct nameidata *);
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struct file_operations autofs4_root_operations = {
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.open = dcache_dir_open,
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@ -46,7 +47,7 @@ struct file_operations autofs4_dir_operations = {
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.readdir = autofs4_dir_readdir,
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};
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struct inode_operations autofs4_root_inode_operations = {
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struct inode_operations autofs4_indirect_root_inode_operations = {
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.lookup = autofs4_lookup,
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.unlink = autofs4_dir_unlink,
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.symlink = autofs4_dir_symlink,
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@ -54,6 +55,11 @@ struct inode_operations autofs4_root_inode_operations = {
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.rmdir = autofs4_dir_rmdir,
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};
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struct inode_operations autofs4_direct_root_inode_operations = {
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.lookup = autofs4_lookup,
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.follow_link = autofs4_follow_link,
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};
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struct inode_operations autofs4_dir_inode_operations = {
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.lookup = autofs4_lookup,
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.unlink = autofs4_dir_unlink,
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@ -252,7 +258,7 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
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*/
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status = d_invalidate(dentry);
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if (status != -EBUSY)
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return 0;
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return -ENOENT;
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}
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DPRINTK("dentry=%p %.*s ino=%p",
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@ -271,17 +277,17 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
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DPRINTK("mount done status=%d", status);
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if (status && dentry->d_inode)
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return 0; /* Try to get the kernel to invalidate this dentry */
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return status; /* Try to get the kernel to invalidate this dentry */
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/* Turn this into a real negative dentry? */
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if (status == -ENOENT) {
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spin_lock(&dentry->d_lock);
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dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
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spin_unlock(&dentry->d_lock);
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return 0;
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return status;
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} else if (status) {
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/* Return a negative dentry, but leave it "pending" */
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return 0;
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return status;
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}
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/* Trigger mount for path component or follow link */
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} else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
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@ -300,7 +306,7 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
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spin_lock(&dentry->d_lock);
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dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
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spin_unlock(&dentry->d_lock);
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return 0;
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return status;
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}
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}
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@ -311,7 +317,41 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
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spin_lock(&dentry->d_lock);
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dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
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spin_unlock(&dentry->d_lock);
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return 1;
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return status;
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}
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/* For autofs direct mounts the follow link triggers the mount */
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static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
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{
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struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
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int oz_mode = autofs4_oz_mode(sbi);
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unsigned int lookup_type;
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int status;
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DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
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dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
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nd->flags);
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/* If it's our master or we shouldn't trigger a mount we're done */
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lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY);
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if (oz_mode || !lookup_type)
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goto done;
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status = try_to_fill_dentry(dentry, 0);
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if (status)
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goto out_error;
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if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {
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status = -ENOENT;
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goto out_error;
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}
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done:
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return NULL;
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out_error:
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path_release(nd);
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return ERR_PTR(status);
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}
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/*
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@ -326,13 +366,13 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
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struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
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int oz_mode = autofs4_oz_mode(sbi);
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int flags = nd ? nd->flags : 0;
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int status = 1;
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int status = 0;
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/* Pending dentry */
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if (autofs4_ispending(dentry)) {
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if (!oz_mode)
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status = try_to_fill_dentry(dentry, flags);
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return status;
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return !status;
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}
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/* Negative dentry.. invalidate if "old" */
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@ -349,14 +389,14 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
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spin_unlock(&dcache_lock);
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if (!oz_mode)
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status = try_to_fill_dentry(dentry, flags);
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return status;
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return !status;
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}
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spin_unlock(&dcache_lock);
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return 1;
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}
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static void autofs4_dentry_release(struct dentry *de)
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void autofs4_dentry_release(struct dentry *de)
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{
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struct autofs_info *inf;
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