| /* -*- c -*- --------------------------------------------------------------- * |
| * |
| * linux/fs/autofs/inode.c |
| * |
| * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved |
| * Copyright 2005-2006 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 |
| * option, any later version, incorporated herein by reference. |
| * |
| * ------------------------------------------------------------------------- */ |
| |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/file.h> |
| #include <linux/seq_file.h> |
| #include <linux/pagemap.h> |
| #include <linux/parser.h> |
| #include <linux/bitops.h> |
| #include <linux/smp_lock.h> |
| #include "autofs_i.h" |
| #include <linux/module.h> |
| |
| static void ino_lnkfree(struct autofs_info *ino) |
| { |
| kfree(ino->u.symlink); |
| ino->u.symlink = NULL; |
| } |
| |
| struct autofs_info *autofs4_init_ino(struct autofs_info *ino, |
| struct autofs_sb_info *sbi, mode_t mode) |
| { |
| int reinit = 1; |
| |
| if (ino == NULL) { |
| reinit = 0; |
| ino = kmalloc(sizeof(*ino), GFP_KERNEL); |
| } |
| |
| if (ino == NULL) |
| return NULL; |
| |
| ino->flags = 0; |
| ino->mode = mode; |
| ino->inode = NULL; |
| ino->dentry = NULL; |
| ino->size = 0; |
| |
| ino->last_used = jiffies; |
| atomic_set(&ino->count, 0); |
| |
| ino->sbi = sbi; |
| |
| if (reinit && ino->free) |
| (ino->free)(ino); |
| |
| memset(&ino->u, 0, sizeof(ino->u)); |
| |
| ino->free = NULL; |
| |
| if (S_ISLNK(mode)) |
| ino->free = ino_lnkfree; |
| |
| return ino; |
| } |
| |
| void autofs4_free_ino(struct autofs_info *ino) |
| { |
| struct autofs_info *p_ino; |
| |
| if (ino->dentry) { |
| ino->dentry->d_fsdata = NULL; |
| if (ino->dentry->d_inode) { |
| struct dentry *parent = ino->dentry->d_parent; |
| if (atomic_dec_and_test(&ino->count)) { |
| p_ino = autofs4_dentry_ino(parent); |
| if (p_ino && parent != ino->dentry) |
| atomic_dec(&p_ino->count); |
| } |
| dput(ino->dentry); |
| } |
| ino->dentry = NULL; |
| } |
| if (ino->free) |
| (ino->free)(ino); |
| kfree(ino); |
| } |
| |
| /* |
| * Deal with the infamous "Busy inodes after umount ..." message. |
| * |
| * Clean up the dentry tree. This happens with autofs if the user |
| * space program goes away due to a SIGKILL, SIGSEGV etc. |
| */ |
| static void autofs4_force_release(struct autofs_sb_info *sbi) |
| { |
| struct dentry *this_parent = sbi->root; |
| struct list_head *next; |
| |
| spin_lock(&dcache_lock); |
| repeat: |
| next = this_parent->d_subdirs.next; |
| resume: |
| while (next != &this_parent->d_subdirs) { |
| struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child); |
| |
| /* Negative dentry - don`t care */ |
| if (!simple_positive(dentry)) { |
| next = next->next; |
| continue; |
| } |
| |
| if (!list_empty(&dentry->d_subdirs)) { |
| this_parent = dentry; |
| goto repeat; |
| } |
| |
| next = next->next; |
| spin_unlock(&dcache_lock); |
| |
| DPRINTK("dentry %p %.*s", |
| dentry, (int)dentry->d_name.len, dentry->d_name.name); |
| |
| dput(dentry); |
| spin_lock(&dcache_lock); |
| } |
| |
| if (this_parent != sbi->root) { |
| struct dentry *dentry = this_parent; |
| |
| next = this_parent->d_u.d_child.next; |
| this_parent = this_parent->d_parent; |
| spin_unlock(&dcache_lock); |
| DPRINTK("parent dentry %p %.*s", |
| dentry, (int)dentry->d_name.len, dentry->d_name.name); |
| dput(dentry); |
| spin_lock(&dcache_lock); |
| goto resume; |
| } |
| spin_unlock(&dcache_lock); |
| |
| dput(sbi->root); |
| sbi->root = NULL; |
| shrink_dcache_sb(sbi->sb); |
| |
| return; |
| } |
| |
| static void autofs4_put_super(struct super_block *sb) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(sb); |
| |
| sb->s_fs_info = NULL; |
| |
| if ( !sbi->catatonic ) |
| autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */ |
| |
| /* Clean up and release dangling references */ |
| if (sbi) |
| autofs4_force_release(sbi); |
| |
| kfree(sbi); |
| |
| DPRINTK("shutting down"); |
| } |
| |
| static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb); |
| |
| if (!sbi) |
| return 0; |
| |
| seq_printf(m, ",fd=%d", sbi->pipefd); |
| seq_printf(m, ",pgrp=%d", sbi->oz_pgrp); |
| seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ); |
| 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; |
| } |
| |
| static struct super_operations autofs4_sops = { |
| .put_super = autofs4_put_super, |
| .statfs = simple_statfs, |
| .show_options = autofs4_show_options, |
| }; |
| |
| 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"}, |
| {Opt_uid, "uid=%u"}, |
| {Opt_gid, "gid=%u"}, |
| {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, unsigned int *type, |
| int *minproto, int *maxproto) |
| { |
| char *p; |
| substring_t args[MAX_OPT_ARGS]; |
| int option; |
| |
| *uid = current->uid; |
| *gid = current->gid; |
| *pgrp = process_group(current); |
| |
| *minproto = AUTOFS_MIN_PROTO_VERSION; |
| *maxproto = AUTOFS_MAX_PROTO_VERSION; |
| |
| *pipefd = -1; |
| |
| if (!options) |
| return 1; |
| |
| while ((p = strsep(&options, ",")) != NULL) { |
| int token; |
| if (!*p) |
| continue; |
| |
| token = match_token(p, tokens, args); |
| switch (token) { |
| case Opt_fd: |
| if (match_int(args, pipefd)) |
| return 1; |
| break; |
| case Opt_uid: |
| if (match_int(args, &option)) |
| return 1; |
| *uid = option; |
| break; |
| case Opt_gid: |
| if (match_int(args, &option)) |
| return 1; |
| *gid = option; |
| break; |
| case Opt_pgrp: |
| if (match_int(args, &option)) |
| return 1; |
| *pgrp = option; |
| break; |
| case Opt_minproto: |
| if (match_int(args, &option)) |
| return 1; |
| *minproto = option; |
| break; |
| case Opt_maxproto: |
| if (match_int(args, &option)) |
| 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; |
| } |
| } |
| return (*pipefd < 0); |
| } |
| |
| static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi) |
| { |
| struct autofs_info *ino; |
| |
| ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755); |
| if (!ino) |
| return NULL; |
| |
| 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; |
| struct dentry * root; |
| struct file * pipe; |
| int pipefd; |
| struct autofs_sb_info *sbi; |
| struct autofs_info *ino; |
| |
| sbi = (struct autofs_sb_info *) kmalloc(sizeof(*sbi), GFP_KERNEL); |
| if ( !sbi ) |
| goto fail_unlock; |
| DPRINTK("starting up, sbi = %p",sbi); |
| |
| memset(sbi, 0, sizeof(*sbi)); |
| |
| s->s_fs_info = sbi; |
| sbi->magic = AUTOFS_SBI_MAGIC; |
| sbi->root = NULL; |
| sbi->pipefd = -1; |
| sbi->catatonic = 0; |
| sbi->exp_timeout = 0; |
| sbi->oz_pgrp = process_group(current); |
| 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); |
| spin_lock_init(&sbi->fs_lock); |
| sbi->queues = NULL; |
| s->s_blocksize = 1024; |
| s->s_blocksize_bits = 10; |
| s->s_magic = AUTOFS_SUPER_MAGIC; |
| s->s_op = &autofs4_sops; |
| s->s_time_gran = 1; |
| |
| /* |
| * Get the root inode and dentry, but defer checking for errors. |
| */ |
| ino = autofs4_mkroot(sbi); |
| if (!ino) |
| goto fail_free; |
| root_inode = autofs4_get_inode(s, ino); |
| if (!root_inode) |
| goto fail_ino; |
| |
| root = d_alloc_root(root_inode); |
| 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->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) { |
| printk("autofs: kernel does not match daemon version " |
| "daemon (%d, %d) kernel (%d, %d)\n", |
| sbi->min_proto, sbi->max_proto, |
| AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION); |
| goto fail_dput; |
| } |
| |
| /* Establish highest kernel protocol version */ |
| if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION) |
| sbi->version = AUTOFS_MAX_PROTO_VERSION; |
| else |
| sbi->version = sbi->max_proto; |
| sbi->sub_version = AUTOFS_PROTO_SUBVERSION; |
| |
| DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp); |
| pipe = fget(pipefd); |
| |
| if ( !pipe ) { |
| printk("autofs: could not open pipe file descriptor\n"); |
| goto fail_dput; |
| } |
| if ( !pipe->f_op || !pipe->f_op->write ) |
| goto fail_fput; |
| sbi->pipe = pipe; |
| sbi->pipefd = pipefd; |
| |
| /* |
| * Take a reference to the root dentry so we get a chance to |
| * clean up the dentry tree on umount. |
| * See autofs4_force_release. |
| */ |
| sbi->root = dget(root); |
| |
| /* |
| * Success! Install the root dentry now to indicate completion. |
| */ |
| s->s_root = root; |
| return 0; |
| |
| /* |
| * Failure ... clean up. |
| */ |
| fail_fput: |
| printk("autofs: pipe file descriptor does not contain proper ops\n"); |
| fput(pipe); |
| /* fall through */ |
| fail_dput: |
| dput(root); |
| goto fail_free; |
| fail_iput: |
| printk("autofs: get root dentry failed\n"); |
| iput(root_inode); |
| fail_ino: |
| kfree(ino); |
| fail_free: |
| kfree(sbi); |
| fail_unlock: |
| return -EINVAL; |
| } |
| |
| struct inode *autofs4_get_inode(struct super_block *sb, |
| struct autofs_info *inf) |
| { |
| struct inode *inode = new_inode(sb); |
| |
| if (inode == NULL) |
| return NULL; |
| |
| inf->inode = inode; |
| inode->i_mode = inf->mode; |
| if (sb->s_root) { |
| inode->i_uid = sb->s_root->d_inode->i_uid; |
| inode->i_gid = sb->s_root->d_inode->i_gid; |
| } else { |
| inode->i_uid = 0; |
| inode->i_gid = 0; |
| } |
| inode->i_blksize = PAGE_CACHE_SIZE; |
| inode->i_blocks = 0; |
| inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| |
| if (S_ISDIR(inf->mode)) { |
| inode->i_nlink = 2; |
| inode->i_op = &autofs4_dir_inode_operations; |
| inode->i_fop = &autofs4_dir_operations; |
| } else if (S_ISLNK(inf->mode)) { |
| inode->i_size = inf->size; |
| inode->i_op = &autofs4_symlink_inode_operations; |
| } |
| |
| return inode; |
| } |