From 34ca959cfc15cf09ad4da4f31ab034691e51af78 Mon Sep 17 00:00:00 2001 From: Ian Kent Date: Mon, 27 Mar 2006 01:14:54 -0800 Subject: [PATCH] [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/autofs_i.h | 8 ++++++ fs/autofs4/inode.c | 52 +++++++++++++++++++++++++++++------ fs/autofs4/root.c | 64 +++++++++++++++++++++++++++++++++++-------- 3 files changed, 103 insertions(+), 21 deletions(-) diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index bc1b0543d2b6..ed388a1d8fc4 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -3,6 +3,7 @@ * linux/fs/autofs/autofs_i.h * * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved + * Copyright 2005-2006 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 @@ -84,6 +85,10 @@ struct autofs_wait_queue { #define AUTOFS_SBI_MAGIC 0x6d4a556d +#define AUTOFS_TYP_INDIRECT 0x0001 +#define AUTOFS_TYP_DIRECT 0x0002 +#define AUTOFS_TYP_OFFSET 0x0004 + struct autofs_sb_info { u32 magic; struct dentry *root; @@ -96,6 +101,7 @@ struct autofs_sb_info { int min_proto; int max_proto; unsigned long exp_timeout; + unsigned int type; int reghost_enabled; int needs_reghost; struct super_block *sb; @@ -162,6 +168,8 @@ int autofs4_expire_multi(struct super_block *, struct vfsmount *, extern struct inode_operations autofs4_symlink_inode_operations; extern struct inode_operations autofs4_dir_inode_operations; extern struct inode_operations autofs4_root_inode_operations; +extern struct inode_operations autofs4_indirect_root_inode_operations; +extern struct inode_operations autofs4_direct_root_inode_operations; extern struct file_operations autofs4_dir_operations; extern struct file_operations autofs4_root_operations; diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c index d9a71dab40fc..3801bed94e45 100644 --- a/fs/autofs4/inode.c +++ b/fs/autofs4/inode.c @@ -3,6 +3,7 @@ * linux/fs/autofs/inode.c * * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved + * Copyright 2005-2006 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 @@ -177,6 +178,13 @@ static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt) seq_printf(m, ",minproto=%d", sbi->min_proto); seq_printf(m, ",maxproto=%d", sbi->max_proto); + if (sbi->type & AUTOFS_TYP_OFFSET) + seq_printf(m, ",offset"); + else if (sbi->type & AUTOFS_TYP_DIRECT) + seq_printf(m, ",direct"); + else + seq_printf(m, ",indirect"); + return 0; } @@ -186,7 +194,8 @@ static struct super_operations autofs4_sops = { .show_options = autofs4_show_options, }; -enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto}; +enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto, + Opt_indirect, Opt_direct, Opt_offset}; static match_table_t tokens = { {Opt_fd, "fd=%u"}, @@ -195,11 +204,15 @@ static match_table_t tokens = { {Opt_pgrp, "pgrp=%u"}, {Opt_minproto, "minproto=%u"}, {Opt_maxproto, "maxproto=%u"}, + {Opt_indirect, "indirect"}, + {Opt_direct, "direct"}, + {Opt_offset, "offset"}, {Opt_err, NULL} }; static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, - pid_t *pgrp, int *minproto, int *maxproto) + pid_t *pgrp, unsigned int *type, + int *minproto, int *maxproto) { char *p; substring_t args[MAX_OPT_ARGS]; @@ -253,6 +266,15 @@ static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, return 1; *maxproto = option; break; + case Opt_indirect: + *type = AUTOFS_TYP_INDIRECT; + break; + case Opt_direct: + *type = AUTOFS_TYP_DIRECT; + break; + case Opt_offset: + *type = AUTOFS_TYP_DIRECT | AUTOFS_TYP_OFFSET; + break; default: return 1; } @@ -271,6 +293,11 @@ static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi) return ino; } +void autofs4_dentry_release(struct dentry *); +static struct dentry_operations autofs4_sb_dentry_operations = { + .d_release = autofs4_dentry_release, +}; + int autofs4_fill_super(struct super_block *s, void *data, int silent) { struct inode * root_inode; @@ -297,6 +324,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) sbi->sb = s; sbi->version = 0; sbi->sub_version = 0; + sbi->type = 0; sbi->min_proto = 0; sbi->max_proto = 0; mutex_init(&sbi->wq_mutex); @@ -315,27 +343,31 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) if (!ino) goto fail_free; root_inode = autofs4_get_inode(s, ino); - kfree(ino); if (!root_inode) - goto fail_free; + goto fail_ino; - root_inode->i_op = &autofs4_root_inode_operations; - root_inode->i_fop = &autofs4_root_operations; root = d_alloc_root(root_inode); - pipe = NULL; - if (!root) goto fail_iput; + pipe = NULL; + + root->d_op = &autofs4_sb_dentry_operations; + root->d_fsdata = ino; /* Can this call block? */ if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid, - &sbi->oz_pgrp, + &sbi->oz_pgrp, &sbi->type, &sbi->min_proto, &sbi->max_proto)) { printk("autofs: called with bogus options\n"); goto fail_dput; } + root_inode->i_fop = &autofs4_root_operations; + root_inode->i_op = sbi->type & AUTOFS_TYP_DIRECT ? + &autofs4_direct_root_inode_operations : + &autofs4_indirect_root_inode_operations; + /* Couldn't this be tested earlier? */ if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION || sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) { @@ -391,6 +423,8 @@ fail_dput: fail_iput: printk("autofs: get root dentry failed\n"); iput(root_inode); +fail_ino: + kfree(ino); fail_free: kfree(sbi); fail_unlock: diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 26eb1f024866..3f0048582248 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; -- 2.20.1