LCOV - code coverage report
Current view: top level - lkbce/fs/autofs4 - inode.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 131 286 45.8 %
Date: 2017-01-25 Functions: 6 10 60.0 %

          Line data    Source code
       1             : /* -*- c -*- --------------------------------------------------------------- *
       2             :  *
       3             :  * linux/fs/autofs/inode.c
       4             :  *
       5             :  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
       6             :  *  Copyright 2005-2006 Ian Kent <raven@themaw.net>
       7             :  *
       8             :  * This file is part of the Linux kernel and is made available under
       9             :  * the terms of the GNU General Public License, version 2, or at your
      10             :  * option, any later version, incorporated herein by reference.
      11             :  *
      12             :  * ------------------------------------------------------------------------- */
      13             : 
      14             : #include <linux/kernel.h>
      15             : #include <linux/slab.h>
      16             : #include <linux/file.h>
      17             : #include <linux/seq_file.h>
      18             : #include <linux/pagemap.h>
      19             : #include <linux/parser.h>
      20             : #include <linux/bitops.h>
      21             : #include <linux/magic.h>
      22             : #include "autofs_i.h"
      23             : #include <linux/module.h>
      24             : 
      25             : static void ino_lnkfree(struct autofs_info *ino)
      26             : {
      27           0 :         if (ino->u.symlink) {
      28           0 :                 kfree(ino->u.symlink);
      29           0 :                 ino->u.symlink = NULL;
      30             :         }
      31           0 : }
      32             : 
      33             : struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
      34             :                                      struct autofs_sb_info *sbi, mode_t mode)
      35             : {
      36           6 :         int reinit = 1;
      37           3 : 
      38           6 :         if (ino == NULL) {
      39           3 :                 reinit = 0;
      40           9 :                 ino = kmalloc(sizeof(*ino), GFP_KERNEL);
      41             :         }
      42             : 
      43          12 :         if (ino == NULL)
      44           6 :                 return NULL;
      45             : 
      46          12 :         if (!reinit) {
      47           6 :                 ino->flags = 0;
      48           6 :                 ino->inode = NULL;
      49           6 :                 ino->dentry = NULL;
      50           6 :                 ino->size = 0;
      51          12 :                 INIT_LIST_HEAD(&ino->active);
      52           6 :                 INIT_LIST_HEAD(&ino->rehash_list);
      53           3 :                 ino->active_count = 0;
      54           6 :                 INIT_LIST_HEAD(&ino->expiring);
      55           6 :                 atomic_set(&ino->count, 0);
      56             :         }
      57             : 
      58           9 :         ino->uid = 0;
      59           9 :         ino->gid = 0;
      60           9 :         ino->mode = mode;
      61           9 :         ino->last_used = jiffies;
      62             : 
      63           9 :         ino->sbi = sbi;
      64             : 
      65          45 :         if (reinit && ino->free)
      66          18 :                 (ino->free)(ino);
      67             : 
      68           9 :         memset(&ino->u, 0, sizeof(ino->u));
      69             : 
      70           9 :         ino->free = NULL;
      71             : 
      72          18 :         if (S_ISLNK(mode))
      73           9 :                 ino->free = ino_lnkfree;
      74             : 
      75           9 :         return ino;
      76             : }
      77             : 
      78             : void autofs4_free_ino(struct autofs_info *ino)
      79             : {
      80           2 :         struct autofs_info *p_ino;
      81           2 : 
      82           8 :         if (ino->dentry) {
      83           2 :                 ino->dentry->d_fsdata = NULL;
      84           6 :                 if (ino->dentry->d_inode) {
      85           2 :                         struct dentry *parent = ino->dentry->d_parent;
      86           8 :                         if (atomic_dec_and_test(&ino->count)) {
      87           4 :                                 p_ino = autofs4_dentry_ino(parent);
      88          10 :                                 if (p_ino && parent != ino->dentry)
      89           4 :                                         atomic_dec(&p_ino->count);
      90             :                         }
      91           6 :                         dput(ino->dentry);
      92             :                 }
      93           8 :                 ino->dentry = NULL;
      94             :         }
      95          24 :         if (ino->free)
      96          16 :                 (ino->free)(ino);
      97           8 :         kfree(ino);
      98           8 : }
      99             : 
     100             : /*
     101             :  * Deal with the infamous "Busy inodes after umount ..." message.
     102             :  *
     103             :  * Clean up the dentry tree. This happens with autofs if the user
     104             :  * space program goes away due to a SIGKILL, SIGSEGV etc.
     105             :  */
     106             : static void autofs4_force_release(struct autofs_sb_info *sbi)
     107             : {
     108           6 :         struct dentry *this_parent = sbi->sb->s_root;
     109           3 :         struct list_head *next;
     110           3 : 
     111          12 :         if (!sbi->sb->s_root)
     112           6 :                 return;
     113           3 : 
     114           9 :         spin_lock(&dcache_lock);
     115             : repeat:
     116           6 :         next = this_parent->d_subdirs.next;
     117           3 : resume:
     118           9 :         while (next != &this_parent->d_subdirs) {
     119           9 :                 struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
     120           3 : 
     121             :                 /* Negative dentry - don`t care */
     122          15 :                 if (!simple_positive(dentry)) {
     123           3 :                         next = next->next;
     124           3 :                         continue;
     125             :                 }
     126             : 
     127          12 :                 if (!list_empty(&dentry->d_subdirs)) {
     128           3 :                         this_parent = dentry;
     129           3 :                         goto repeat;
     130             :                 }
     131             : 
     132           3 :                 next = next->next;
     133           6 :                 spin_unlock(&dcache_lock);
     134             : 
     135             :                 DPRINTK("dentry %p %.*s",
     136             :                         dentry, (int)dentry->d_name.len, dentry->d_name.name);
     137             : 
     138           3 :                 dput(dentry);
     139           6 :                 spin_lock(&dcache_lock);
     140             :         }
     141           3 : 
     142           9 :         if (this_parent != sbi->sb->s_root) {
     143           3 :                 struct dentry *dentry = this_parent;
     144             : 
     145           3 :                 next = this_parent->d_u.d_child.next;
     146           3 :                 this_parent = this_parent->d_parent;
     147           6 :                 spin_unlock(&dcache_lock);
     148             :                 DPRINTK("parent dentry %p %.*s",
     149             :                         dentry, (int)dentry->d_name.len, dentry->d_name.name);
     150           3 :                 dput(dentry);
     151           6 :                 spin_lock(&dcache_lock);
     152           3 :                 goto resume;
     153             :         }
     154           6 :         spin_unlock(&dcache_lock);
     155           3 : }
     156             : 
     157             : void autofs4_kill_sb(struct super_block *sb)
     158             : {
     159          12 :         struct autofs_sb_info *sbi = autofs4_sbi(sb);
     160           3 : 
     161             :         /*
     162             :          * In the event of a failure in get_sb_nodev the superblock
     163             :          * info is not present so nothing else has been setup, so
     164             :          * just call kill_anon_super when we are called from
     165             :          * deactivate_super.
     166             :          */
     167           6 :         if (!sbi)
     168           3 :                 goto out_kill_sb;
     169             : 
     170             :         /* Free wait queues, close pipe */
     171           9 :         autofs4_catatonic_mode(sbi);
     172             : 
     173             :         /* Clean up and release dangling references */
     174           9 :         autofs4_force_release(sbi);
     175             : 
     176           3 :         sb->s_fs_info = NULL;
     177           3 :         kfree(sbi);
     178             : 
     179           3 : out_kill_sb:
     180             :         DPRINTK("shutting down");
     181           6 :         kill_anon_super(sb);
     182           6 : }
     183             : 
     184             : static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
     185             : {
     186           4 :         struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb);
     187           2 :         struct inode *root_inode = mnt->mnt_sb->s_root->d_inode;
     188           1 : 
     189           3 :         if (!sbi)
     190           2 :                 return 0;
     191             : 
     192           1 :         seq_printf(m, ",fd=%d", sbi->pipefd);
     193           2 :         if (root_inode->i_uid != 0)
     194           1 :                 seq_printf(m, ",uid=%u", root_inode->i_uid);
     195           2 :         if (root_inode->i_gid != 0)
     196           1 :                 seq_printf(m, ",gid=%u", root_inode->i_gid);
     197           1 :         seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
     198           1 :         seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
     199           1 :         seq_printf(m, ",minproto=%d", sbi->min_proto);
     200           1 :         seq_printf(m, ",maxproto=%d", sbi->max_proto);
     201             : 
     202           4 :         if (autofs_type_offset(sbi->type))
     203           1 :                 seq_printf(m, ",offset");
     204           4 :         else if (autofs_type_direct(sbi->type))
     205           1 :                 seq_printf(m, ",direct");
     206             :         else
     207           1 :                 seq_printf(m, ",indirect");
     208             : 
     209           2 :         return 0;
     210             : }
     211             : 
     212           1 : static const struct super_operations autofs4_sops = {
     213             :         .statfs         = simple_statfs,
     214             :         .show_options   = autofs4_show_options,
     215             : };
     216             : 
     217             : enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
     218             :         Opt_indirect, Opt_direct, Opt_offset};
     219             : 
     220           1 : static const match_table_t tokens = {
     221             :         {Opt_fd, "fd=%u"},
     222             :         {Opt_uid, "uid=%u"},
     223             :         {Opt_gid, "gid=%u"},
     224             :         {Opt_pgrp, "pgrp=%u"},
     225             :         {Opt_minproto, "minproto=%u"},
     226             :         {Opt_maxproto, "maxproto=%u"},
     227             :         {Opt_indirect, "indirect"},
     228             :         {Opt_direct, "direct"},
     229             :         {Opt_offset, "offset"},
     230             :         {Opt_err, NULL}
     231             : };
     232             : 
     233             : static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
     234             :                 pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto)
     235             : {
     236           0 :         char *p;
     237           0 :         substring_t args[MAX_OPT_ARGS];
     238           0 :         int option;
     239           0 : 
     240           0 :         *uid = current_uid();
     241           0 :         *gid = current_gid();
     242           0 :         *pgrp = task_pgrp_nr(current);
     243           0 : 
     244           0 :         *minproto = AUTOFS_MIN_PROTO_VERSION;
     245           0 :         *maxproto = AUTOFS_MAX_PROTO_VERSION;
     246           0 : 
     247           0 :         *pipefd = -1;
     248           0 : 
     249           0 :         if (!options)
     250           0 :                 return 1;
     251             : 
     252           0 :         while ((p = strsep(&options, ",")) != NULL) {
     253           0 :                 int token;
     254           0 :                 if (!*p)
     255           0 :                         continue;
     256             : 
     257           0 :                 token = match_token(p, tokens, args);
     258             :                 switch (token) {
     259           0 :                 case Opt_fd:
     260           0 :                         if (match_int(args, pipefd))
     261           0 :                                 return 1;
     262           0 :                         break;
     263           0 :                 case Opt_uid:
     264           0 :                         if (match_int(args, &option))
     265           0 :                                 return 1;
     266           0 :                         *uid = option;
     267           0 :                         break;
     268           0 :                 case Opt_gid:
     269           0 :                         if (match_int(args, &option))
     270           0 :                                 return 1;
     271           0 :                         *gid = option;
     272           0 :                         break;
     273           0 :                 case Opt_pgrp:
     274           0 :                         if (match_int(args, &option))
     275           0 :                                 return 1;
     276           0 :                         *pgrp = option;
     277           0 :                         break;
     278           0 :                 case Opt_minproto:
     279           0 :                         if (match_int(args, &option))
     280           0 :                                 return 1;
     281           0 :                         *minproto = option;
     282           0 :                         break;
     283           0 :                 case Opt_maxproto:
     284           0 :                         if (match_int(args, &option))
     285           0 :                                 return 1;
     286           0 :                         *maxproto = option;
     287           0 :                         break;
     288           0 :                 case Opt_indirect:
     289           0 :                         set_autofs_type_indirect(type);
     290           0 :                         break;
     291           0 :                 case Opt_direct:
     292           0 :                         set_autofs_type_direct(type);
     293           0 :                         break;
     294           0 :                 case Opt_offset:
     295           0 :                         set_autofs_type_offset(type);
     296           0 :                         break;
     297           0 :                 default:
     298           0 :                         return 1;
     299             :                 }
     300             :         }
     301           0 :         return (*pipefd < 0);
     302           0 : }
     303             : 
     304             : static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
     305             : {
     306           0 :         struct autofs_info *ino;
     307             : 
     308           0 :         ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755);
     309           0 :         if (!ino)
     310           0 :                 return NULL;
     311             : 
     312           0 :         return ino;
     313             : }
     314             : 
     315           1 : static const struct dentry_operations autofs4_sb_dentry_operations = {
     316             :         .d_release      = autofs4_dentry_release,
     317             : };
     318             : 
     319             : int autofs4_fill_super(struct super_block *s, void *data, int silent)
     320             : {
     321           0 :         struct inode * root_inode;
     322           0 :         struct dentry * root;
     323           0 :         struct file * pipe;
     324           0 :         int pipefd;
     325           0 :         struct autofs_sb_info *sbi;
     326           0 :         struct autofs_info *ino;
     327           0 : 
     328           0 :         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
     329           0 :         if (!sbi)
     330           0 :                 goto fail_unlock;
     331           0 :         DPRINTK("starting up, sbi = %p",sbi);
     332           0 : 
     333           0 :         s->s_fs_info = sbi;
     334           0 :         sbi->magic = AUTOFS_SBI_MAGIC;
     335           0 :         sbi->pipefd = -1;
     336           0 :         sbi->pipe = NULL;
     337           0 :         sbi->catatonic = 1;
     338           0 :         sbi->exp_timeout = 0;
     339           0 :         sbi->oz_pgrp = task_pgrp_nr(current);
     340           0 :         sbi->sb = s;
     341           0 :         sbi->version = 0;
     342           0 :         sbi->sub_version = 0;
     343           0 :         set_autofs_type_indirect(&sbi->type);
     344           0 :         sbi->min_proto = 0;
     345           0 :         sbi->max_proto = 0;
     346           0 :         mutex_init(&sbi->wq_mutex);
     347           0 :         spin_lock_init(&sbi->fs_lock);
     348           0 :         sbi->queues = NULL;
     349           0 :         spin_lock_init(&sbi->lookup_lock);
     350           0 :         INIT_LIST_HEAD(&sbi->active_list);
     351           0 :         INIT_LIST_HEAD(&sbi->expiring_list);
     352           0 :         s->s_blocksize = 1024;
     353           0 :         s->s_blocksize_bits = 10;
     354           0 :         s->s_magic = AUTOFS_SUPER_MAGIC;
     355           0 :         s->s_op = &autofs4_sops;
     356           0 :         s->s_time_gran = 1;
     357             : 
     358             :         /*
     359             :          * Get the root inode and dentry, but defer checking for errors.
     360             :          */
     361           0 :         ino = autofs4_mkroot(sbi);
     362           0 :         if (!ino)
     363           0 :                 goto fail_free;
     364           0 :         root_inode = autofs4_get_inode(s, ino);
     365           0 :         if (!root_inode)
     366           0 :                 goto fail_ino;
     367             : 
     368           0 :         root = d_alloc_root(root_inode);
     369           0 :         if (!root)
     370           0 :                 goto fail_iput;
     371           0 :         pipe = NULL;
     372             : 
     373           0 :         root->d_op = &autofs4_sb_dentry_operations;
     374           0 :         root->d_fsdata = ino;
     375             : 
     376             :         /* Can this call block? */
     377           0 :         if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
     378             :                                 &sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
     379             :                                 &sbi->max_proto)) {
     380           0 :                 printk("autofs: called with bogus options\n");
     381           0 :                 goto fail_dput;
     382             :         }
     383             : 
     384           0 :         root_inode->i_fop = &autofs4_root_operations;
     385           0 :         root_inode->i_op = autofs_type_trigger(sbi->type) ?
     386             :                         &autofs4_direct_root_inode_operations :
     387             :                         &autofs4_indirect_root_inode_operations;
     388             : 
     389             :         /* Couldn't this be tested earlier? */
     390           0 :         if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
     391             :             sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
     392           0 :                 printk("autofs: kernel does not match daemon version "
     393             :                        "daemon (%d, %d) kernel (%d, %d)\n",
     394             :                         sbi->min_proto, sbi->max_proto,
     395             :                         AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
     396           0 :                 goto fail_dput;
     397             :         }
     398             : 
     399             :         /* Establish highest kernel protocol version */
     400           0 :         if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
     401           0 :                 sbi->version = AUTOFS_MAX_PROTO_VERSION;
     402             :         else
     403           0 :                 sbi->version = sbi->max_proto;
     404           0 :         sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
     405             : 
     406             :         DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
     407           0 :         pipe = fget(pipefd);
     408             :         
     409           0 :         if (!pipe) {
     410           0 :                 printk("autofs: could not open pipe file descriptor\n");
     411           0 :                 goto fail_dput;
     412             :         }
     413           0 :         if (!pipe->f_op || !pipe->f_op->write)
     414           0 :                 goto fail_fput;
     415           0 :         sbi->pipe = pipe;
     416           0 :         sbi->pipefd = pipefd;
     417           0 :         sbi->catatonic = 0;
     418             : 
     419             :         /*
     420             :          * Success! Install the root dentry now to indicate completion.
     421             :          */
     422           0 :         s->s_root = root;
     423           0 :         return 0;
     424           0 :         
     425             :         /*
     426             :          * Failure ... clean up.
     427             :          */
     428             : fail_fput:
     429           0 :         printk("autofs: pipe file descriptor does not contain proper ops\n");
     430           0 :         fput(pipe);
     431             :         /* fall through */
     432           0 : fail_dput:
     433           0 :         dput(root);
     434           0 :         goto fail_free;
     435           0 : fail_iput:
     436           0 :         printk("autofs: get root dentry failed\n");
     437           0 :         iput(root_inode);
     438             : fail_ino:
     439           0 :         kfree(ino);
     440             : fail_free:
     441           0 :         kfree(sbi);
     442           0 :         s->s_fs_info = NULL;
     443             : fail_unlock:
     444           0 :         return -EINVAL;
     445             : }
     446             : 
     447             : struct inode *autofs4_get_inode(struct super_block *sb,
     448             :                                 struct autofs_info *inf)
     449           2 : {
     450           6 :         struct inode *inode = new_inode(sb);
     451           2 : 
     452           6 :         if (inode == NULL)
     453           2 :                 return NULL;
     454             : 
     455           2 :         inf->inode = inode;
     456           4 :         inode->i_mode = inf->mode;
     457           6 :         if (sb->s_root) {
     458           2 :                 inode->i_uid = sb->s_root->d_inode->i_uid;
     459           2 :                 inode->i_gid = sb->s_root->d_inode->i_gid;
     460             :         }
     461          10 :         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
     462             : 
     463           4 :         if (S_ISDIR(inf->mode)) {
     464           2 :                 inode->i_nlink = 2;
     465           2 :                 inode->i_op = &autofs4_dir_inode_operations;
     466           2 :                 inode->i_fop = &autofs4_dir_operations;
     467           4 :         } else if (S_ISLNK(inf->mode)) {
     468           4 :                 inode->i_size = inf->size;
     469           2 :                 inode->i_op = &autofs4_symlink_inode_operations;
     470             :         }
     471             : 
     472           2 :         return inode;
     473             : }

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