Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* -*- c -*- --------------------------------------------------------------- * |
| 2 | * |
| 3 | * linux/fs/autofs/root.c |
| 4 | * |
| 5 | * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved |
| 6 | * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> |
Ian Kent | 34ca959 | 2006-03-27 01:14:54 -0800 | [diff] [blame] | 7 | * Copyright 2001-2006 Ian Kent <raven@themaw.net> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | * |
| 9 | * This file is part of the Linux kernel and is made available under |
| 10 | * the terms of the GNU General Public License, version 2, or at your |
| 11 | * option, any later version, incorporated herein by reference. |
| 12 | * |
| 13 | * ------------------------------------------------------------------------- */ |
| 14 | |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 15 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/errno.h> |
| 17 | #include <linux/stat.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 18 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <linux/param.h> |
| 20 | #include <linux/time.h> |
Arnd Bergmann | c9243f5 | 2010-07-04 00:15:07 +0200 | [diff] [blame] | 21 | #include <linux/compat.h> |
Arnd Bergmann | 00e300e | 2010-09-14 23:00:34 +0200 | [diff] [blame] | 22 | #include <linux/mutex.h> |
Arnd Bergmann | c9243f5 | 2010-07-04 00:15:07 +0200 | [diff] [blame] | 23 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include "autofs_i.h" |
| 25 | |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 26 | DEFINE_SPINLOCK(autofs4_lock); |
| 27 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); |
| 29 | static int autofs4_dir_unlink(struct inode *,struct dentry *); |
| 30 | static int autofs4_dir_rmdir(struct inode *,struct dentry *); |
| 31 | static int autofs4_dir_mkdir(struct inode *,struct dentry *,int); |
Frederic Weisbecker | 3663df7 | 2010-05-19 15:08:17 +0200 | [diff] [blame] | 32 | static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long); |
Felipe Contreras | 5a44a73 | 2010-09-24 15:22:23 +0200 | [diff] [blame] | 33 | #ifdef CONFIG_COMPAT |
Arnd Bergmann | c9243f5 | 2010-07-04 00:15:07 +0200 | [diff] [blame] | 34 | static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long); |
Felipe Contreras | 5a44a73 | 2010-09-24 15:22:23 +0200 | [diff] [blame] | 35 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | static int autofs4_dir_open(struct inode *inode, struct file *file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); |
Ian Kent | 71e469d | 2011-01-14 18:46:19 +0000 | [diff] [blame] | 38 | static struct vfsmount *autofs4_d_automount(struct path *); |
David Howells | ab90911 | 2011-01-14 18:46:51 +0000 | [diff] [blame] | 39 | static int autofs4_d_manage(struct dentry *, bool, bool); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 41 | const struct file_operations autofs4_root_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | .open = dcache_dir_open, |
| 43 | .release = dcache_dir_close, |
| 44 | .read = generic_read_dir, |
Ian Kent | aa55ddf | 2008-07-23 21:30:29 -0700 | [diff] [blame] | 45 | .readdir = dcache_readdir, |
Al Viro | 59af158 | 2008-08-24 07:24:41 -0400 | [diff] [blame] | 46 | .llseek = dcache_dir_lseek, |
Frederic Weisbecker | 3663df7 | 2010-05-19 15:08:17 +0200 | [diff] [blame] | 47 | .unlocked_ioctl = autofs4_root_ioctl, |
Arnd Bergmann | c9243f5 | 2010-07-04 00:15:07 +0200 | [diff] [blame] | 48 | #ifdef CONFIG_COMPAT |
| 49 | .compat_ioctl = autofs4_root_compat_ioctl, |
| 50 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | }; |
| 52 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 53 | const struct file_operations autofs4_dir_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | .open = autofs4_dir_open, |
Ian Kent | ff9cd49 | 2008-07-23 21:30:24 -0700 | [diff] [blame] | 55 | .release = dcache_dir_close, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | .read = generic_read_dir, |
Ian Kent | ff9cd49 | 2008-07-23 21:30:24 -0700 | [diff] [blame] | 57 | .readdir = dcache_readdir, |
Al Viro | 59af158 | 2008-08-24 07:24:41 -0400 | [diff] [blame] | 58 | .llseek = dcache_dir_lseek, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | }; |
| 60 | |
Arjan van de Ven | 754661f | 2007-02-12 00:55:38 -0800 | [diff] [blame] | 61 | const struct inode_operations autofs4_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | .lookup = autofs4_lookup, |
| 63 | .unlink = autofs4_dir_unlink, |
| 64 | .symlink = autofs4_dir_symlink, |
| 65 | .mkdir = autofs4_dir_mkdir, |
| 66 | .rmdir = autofs4_dir_rmdir, |
| 67 | }; |
| 68 | |
Ian Kent | 71e469d | 2011-01-14 18:46:19 +0000 | [diff] [blame] | 69 | /* For dentries that don't initiate mounting */ |
| 70 | const struct dentry_operations autofs4_dentry_operations = { |
| 71 | .d_release = autofs4_dentry_release, |
| 72 | }; |
| 73 | |
| 74 | /* For dentries that do initiate mounting */ |
| 75 | const struct dentry_operations autofs4_mount_dentry_operations = { |
| 76 | .d_automount = autofs4_d_automount, |
| 77 | .d_manage = autofs4_d_manage, |
| 78 | .d_release = autofs4_dentry_release, |
| 79 | }; |
| 80 | |
Ian Kent | 4f8427d | 2009-12-15 16:45:42 -0800 | [diff] [blame] | 81 | static void autofs4_add_active(struct dentry *dentry) |
| 82 | { |
| 83 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| 84 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| 85 | if (ino) { |
| 86 | spin_lock(&sbi->lookup_lock); |
| 87 | if (!ino->active_count) { |
| 88 | if (list_empty(&ino->active)) |
| 89 | list_add(&ino->active, &sbi->active_list); |
| 90 | } |
| 91 | ino->active_count++; |
| 92 | spin_unlock(&sbi->lookup_lock); |
| 93 | } |
| 94 | return; |
| 95 | } |
| 96 | |
| 97 | static void autofs4_del_active(struct dentry *dentry) |
| 98 | { |
| 99 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| 100 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| 101 | if (ino) { |
| 102 | spin_lock(&sbi->lookup_lock); |
| 103 | ino->active_count--; |
| 104 | if (!ino->active_count) { |
| 105 | if (!list_empty(&ino->active)) |
| 106 | list_del_init(&ino->active); |
| 107 | } |
| 108 | spin_unlock(&sbi->lookup_lock); |
| 109 | } |
| 110 | return; |
| 111 | } |
| 112 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
| 114 | { |
Josef "Jeff" Sipek | a4669ed | 2006-12-08 02:36:46 -0800 | [diff] [blame] | 115 | struct dentry *dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
Ian Kent | f360ce3 | 2006-03-27 01:14:43 -0800 | [diff] [blame] | 117 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | DPRINTK("file=%p dentry=%p %.*s", |
| 119 | file, dentry, dentry->d_name.len, dentry->d_name.name); |
| 120 | |
| 121 | if (autofs4_oz_mode(sbi)) |
| 122 | goto out; |
| 123 | |
Ian Kent | ff9cd49 | 2008-07-23 21:30:24 -0700 | [diff] [blame] | 124 | /* |
| 125 | * An empty directory in an autofs file system is always a |
| 126 | * mount point. The daemon must have failed to mount this |
| 127 | * during lookup so it doesn't exist. This can happen, for |
| 128 | * example, if user space returns an incorrect status for a |
| 129 | * mount request. Otherwise we're doing a readdir on the |
| 130 | * autofs file system so just let the libfs routines handle |
| 131 | * it. |
| 132 | */ |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 133 | spin_lock(&autofs4_lock); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 134 | spin_lock(&dentry->d_lock); |
Ian Kent | c42c7f7 | 2009-12-15 16:45:48 -0800 | [diff] [blame] | 135 | if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 136 | spin_unlock(&dentry->d_lock); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 137 | spin_unlock(&autofs4_lock); |
Ian Kent | ff9cd49 | 2008-07-23 21:30:24 -0700 | [diff] [blame] | 138 | return -ENOENT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | } |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 140 | spin_unlock(&dentry->d_lock); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 141 | spin_unlock(&autofs4_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | |
Ian Kent | f360ce3 | 2006-03-27 01:14:43 -0800 | [diff] [blame] | 143 | out: |
Ian Kent | ff9cd49 | 2008-07-23 21:30:24 -0700 | [diff] [blame] | 144 | return dcache_dir_open(inode, file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | } |
| 146 | |
Ian Kent | 34ca959 | 2006-03-27 01:14:54 -0800 | [diff] [blame] | 147 | void autofs4_dentry_release(struct dentry *de) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | { |
| 149 | struct autofs_info *inf; |
| 150 | |
| 151 | DPRINTK("releasing %p", de); |
| 152 | |
| 153 | inf = autofs4_dentry_ino(de); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | if (inf) { |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 155 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 156 | if (sbi) { |
Ian Kent | 5f6f4f2 | 2008-07-23 21:30:09 -0700 | [diff] [blame] | 157 | spin_lock(&sbi->lookup_lock); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 158 | if (!list_empty(&inf->active)) |
| 159 | list_del(&inf->active); |
Ian Kent | 5f6f4f2 | 2008-07-23 21:30:09 -0700 | [diff] [blame] | 160 | if (!list_empty(&inf->expiring)) |
| 161 | list_del(&inf->expiring); |
| 162 | spin_unlock(&sbi->lookup_lock); |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 163 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | autofs4_free_ino(inf); |
| 165 | } |
| 166 | } |
| 167 | |
Ian Kent | 6510c9d | 2009-12-15 16:45:47 -0800 | [diff] [blame] | 168 | static struct dentry *autofs4_lookup_active(struct dentry *dentry) |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 169 | { |
Ian Kent | 6510c9d | 2009-12-15 16:45:47 -0800 | [diff] [blame] | 170 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| 171 | struct dentry *parent = dentry->d_parent; |
| 172 | struct qstr *name = &dentry->d_name; |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 173 | unsigned int len = name->len; |
| 174 | unsigned int hash = name->hash; |
| 175 | const unsigned char *str = name->name; |
| 176 | struct list_head *p, *head; |
| 177 | |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 178 | spin_lock(&autofs4_lock); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 179 | spin_lock(&sbi->lookup_lock); |
| 180 | head = &sbi->active_list; |
| 181 | list_for_each(p, head) { |
| 182 | struct autofs_info *ino; |
Ian Kent | e4d5ade | 2009-12-15 16:45:49 -0800 | [diff] [blame] | 183 | struct dentry *active; |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 184 | struct qstr *qstr; |
| 185 | |
| 186 | ino = list_entry(p, struct autofs_info, active); |
Ian Kent | e4d5ade | 2009-12-15 16:45:49 -0800 | [diff] [blame] | 187 | active = ino->dentry; |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 188 | |
Ian Kent | e4d5ade | 2009-12-15 16:45:49 -0800 | [diff] [blame] | 189 | spin_lock(&active->d_lock); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 190 | |
| 191 | /* Already gone? */ |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 192 | if (active->d_count == 0) |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 193 | goto next; |
| 194 | |
Ian Kent | e4d5ade | 2009-12-15 16:45:49 -0800 | [diff] [blame] | 195 | qstr = &active->d_name; |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 196 | |
Ian Kent | e4d5ade | 2009-12-15 16:45:49 -0800 | [diff] [blame] | 197 | if (active->d_name.hash != hash) |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 198 | goto next; |
Ian Kent | e4d5ade | 2009-12-15 16:45:49 -0800 | [diff] [blame] | 199 | if (active->d_parent != parent) |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 200 | goto next; |
| 201 | |
| 202 | if (qstr->len != len) |
| 203 | goto next; |
| 204 | if (memcmp(qstr->name, str, len)) |
| 205 | goto next; |
| 206 | |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 207 | if (d_unhashed(active)) { |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 208 | dget_dlock(active); |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 209 | spin_unlock(&active->d_lock); |
| 210 | spin_unlock(&sbi->lookup_lock); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 211 | spin_unlock(&autofs4_lock); |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 212 | return active; |
| 213 | } |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 214 | next: |
Ian Kent | e4d5ade | 2009-12-15 16:45:49 -0800 | [diff] [blame] | 215 | spin_unlock(&active->d_lock); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 216 | } |
| 217 | spin_unlock(&sbi->lookup_lock); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 218 | spin_unlock(&autofs4_lock); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 219 | |
| 220 | return NULL; |
| 221 | } |
| 222 | |
Ian Kent | 6510c9d | 2009-12-15 16:45:47 -0800 | [diff] [blame] | 223 | static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 224 | { |
Ian Kent | 6510c9d | 2009-12-15 16:45:47 -0800 | [diff] [blame] | 225 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| 226 | struct dentry *parent = dentry->d_parent; |
| 227 | struct qstr *name = &dentry->d_name; |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 228 | unsigned int len = name->len; |
| 229 | unsigned int hash = name->hash; |
| 230 | const unsigned char *str = name->name; |
| 231 | struct list_head *p, *head; |
| 232 | |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 233 | spin_lock(&autofs4_lock); |
Ian Kent | 5f6f4f2 | 2008-07-23 21:30:09 -0700 | [diff] [blame] | 234 | spin_lock(&sbi->lookup_lock); |
| 235 | head = &sbi->expiring_list; |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 236 | list_for_each(p, head) { |
| 237 | struct autofs_info *ino; |
Ian Kent | cb4b492 | 2009-12-15 16:45:50 -0800 | [diff] [blame] | 238 | struct dentry *expiring; |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 239 | struct qstr *qstr; |
| 240 | |
Ian Kent | 5f6f4f2 | 2008-07-23 21:30:09 -0700 | [diff] [blame] | 241 | ino = list_entry(p, struct autofs_info, expiring); |
Ian Kent | cb4b492 | 2009-12-15 16:45:50 -0800 | [diff] [blame] | 242 | expiring = ino->dentry; |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 243 | |
Ian Kent | cb4b492 | 2009-12-15 16:45:50 -0800 | [diff] [blame] | 244 | spin_lock(&expiring->d_lock); |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 245 | |
| 246 | /* Bad luck, we've already been dentry_iput */ |
Ian Kent | cb4b492 | 2009-12-15 16:45:50 -0800 | [diff] [blame] | 247 | if (!expiring->d_inode) |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 248 | goto next; |
| 249 | |
Ian Kent | cb4b492 | 2009-12-15 16:45:50 -0800 | [diff] [blame] | 250 | qstr = &expiring->d_name; |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 251 | |
Ian Kent | cb4b492 | 2009-12-15 16:45:50 -0800 | [diff] [blame] | 252 | if (expiring->d_name.hash != hash) |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 253 | goto next; |
Ian Kent | cb4b492 | 2009-12-15 16:45:50 -0800 | [diff] [blame] | 254 | if (expiring->d_parent != parent) |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 255 | goto next; |
| 256 | |
| 257 | if (qstr->len != len) |
| 258 | goto next; |
| 259 | if (memcmp(qstr->name, str, len)) |
| 260 | goto next; |
| 261 | |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 262 | if (d_unhashed(expiring)) { |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 263 | dget_dlock(expiring); |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 264 | spin_unlock(&expiring->d_lock); |
| 265 | spin_unlock(&sbi->lookup_lock); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 266 | spin_unlock(&autofs4_lock); |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 267 | return expiring; |
| 268 | } |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 269 | next: |
Ian Kent | cb4b492 | 2009-12-15 16:45:50 -0800 | [diff] [blame] | 270 | spin_unlock(&expiring->d_lock); |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 271 | } |
Ian Kent | 5f6f4f2 | 2008-07-23 21:30:09 -0700 | [diff] [blame] | 272 | spin_unlock(&sbi->lookup_lock); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 273 | spin_unlock(&autofs4_lock); |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 274 | |
| 275 | return NULL; |
| 276 | } |
| 277 | |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 278 | static int autofs4_mount_wait(struct dentry *dentry) |
| 279 | { |
| 280 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| 281 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| 282 | int status; |
| 283 | |
| 284 | if (ino->flags & AUTOFS_INF_PENDING) { |
| 285 | DPRINTK("waiting for mount name=%.*s", |
| 286 | dentry->d_name.len, dentry->d_name.name); |
| 287 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); |
| 288 | DPRINTK("mount wait done status=%d", status); |
| 289 | ino->last_used = jiffies; |
| 290 | return status; |
| 291 | } |
| 292 | return 0; |
| 293 | } |
| 294 | |
| 295 | static int do_expire_wait(struct dentry *dentry) |
| 296 | { |
| 297 | struct dentry *expiring; |
| 298 | |
| 299 | expiring = autofs4_lookup_expiring(dentry); |
| 300 | if (!expiring) |
| 301 | return autofs4_expire_wait(dentry); |
| 302 | else { |
| 303 | /* |
| 304 | * If we are racing with expire the request might not |
| 305 | * be quite complete, but the directory has been removed |
| 306 | * so it must have been successful, just wait for it. |
| 307 | */ |
| 308 | autofs4_expire_wait(expiring); |
| 309 | autofs4_del_expiring(expiring); |
| 310 | dput(expiring); |
| 311 | } |
| 312 | return 0; |
| 313 | } |
| 314 | |
| 315 | static struct dentry *autofs4_mountpoint_changed(struct path *path) |
| 316 | { |
| 317 | struct dentry *dentry = path->dentry; |
| 318 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| 319 | |
| 320 | /* |
| 321 | * If this is an indirect mount the dentry could have gone away |
| 322 | * as a result of an expire and a new one created. |
| 323 | */ |
| 324 | if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { |
| 325 | struct dentry *parent = dentry->d_parent; |
| 326 | struct dentry *new = d_lookup(parent, &dentry->d_name); |
| 327 | if (!new) |
| 328 | return NULL; |
| 329 | dput(path->dentry); |
| 330 | path->dentry = new; |
| 331 | } |
| 332 | return path->dentry; |
| 333 | } |
| 334 | |
Ian Kent | 71e469d | 2011-01-14 18:46:19 +0000 | [diff] [blame] | 335 | static struct vfsmount *autofs4_d_automount(struct path *path) |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 336 | { |
| 337 | struct dentry *dentry = path->dentry; |
| 338 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| 339 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| 340 | int status; |
| 341 | |
| 342 | DPRINTK("dentry=%p %.*s", |
| 343 | dentry, dentry->d_name.len, dentry->d_name.name); |
| 344 | |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 345 | /* |
| 346 | * Someone may have manually umounted this or it was a submount |
| 347 | * that has gone away. |
| 348 | */ |
| 349 | spin_lock(&dentry->d_lock); |
| 350 | if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { |
| 351 | if (!(dentry->d_flags & DCACHE_MANAGE_TRANSIT) && |
| 352 | (dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) |
| 353 | __managed_dentry_set_transit(path->dentry); |
| 354 | } |
| 355 | spin_unlock(&dentry->d_lock); |
| 356 | |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 357 | /* The daemon never triggers a mount. */ |
| 358 | if (autofs4_oz_mode(sbi)) |
| 359 | return NULL; |
| 360 | |
| 361 | /* |
| 362 | * If an expire request is pending everyone must wait. |
| 363 | * If the expire fails we're still mounted so continue |
| 364 | * the follow and return. A return of -EAGAIN (which only |
| 365 | * happens with indirect mounts) means the expire completed |
| 366 | * and the directory was removed, so just go ahead and try |
| 367 | * the mount. |
| 368 | */ |
| 369 | status = do_expire_wait(dentry); |
| 370 | if (status && status != -EAGAIN) |
| 371 | return NULL; |
| 372 | |
| 373 | /* Callback to the daemon to perform the mount or wait */ |
| 374 | spin_lock(&sbi->fs_lock); |
| 375 | if (ino->flags & AUTOFS_INF_PENDING) { |
| 376 | spin_unlock(&sbi->fs_lock); |
| 377 | status = autofs4_mount_wait(dentry); |
| 378 | if (status) |
| 379 | return ERR_PTR(status); |
| 380 | spin_lock(&sbi->fs_lock); |
| 381 | goto done; |
| 382 | } |
| 383 | |
| 384 | /* |
| 385 | * If the dentry is a symlink it's equivalent to a directory |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 386 | * having d_mountpoint() true, so there's no need to call back |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 387 | * to the daemon. |
| 388 | */ |
| 389 | if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) |
| 390 | goto done; |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 391 | if (!d_mountpoint(dentry)) { |
| 392 | /* |
| 393 | * It's possible that user space hasn't removed directories |
| 394 | * after umounting a rootless multi-mount, although it |
| 395 | * should. For v5 have_submounts() is sufficient to handle |
| 396 | * this because the leaves of the directory tree under the |
| 397 | * mount never trigger mounts themselves (they have an autofs |
| 398 | * trigger mount mounted on them). But v4 pseudo direct mounts |
| 399 | * do need the leaves to to trigger mounts. In this case we |
| 400 | * have no choice but to use the list_empty() check and |
| 401 | * require user space behave. |
| 402 | */ |
| 403 | if (sbi->version > 4) { |
| 404 | if (have_submounts(dentry)) |
| 405 | goto done; |
| 406 | } else { |
| 407 | spin_lock(&dentry->d_lock); |
| 408 | if (!list_empty(&dentry->d_subdirs)) { |
| 409 | spin_unlock(&dentry->d_lock); |
| 410 | goto done; |
| 411 | } |
| 412 | spin_unlock(&dentry->d_lock); |
| 413 | } |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 414 | ino->flags |= AUTOFS_INF_PENDING; |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 415 | spin_unlock(&sbi->fs_lock); |
| 416 | status = autofs4_mount_wait(dentry); |
| 417 | if (status) |
| 418 | return ERR_PTR(status); |
| 419 | spin_lock(&sbi->fs_lock); |
| 420 | ino->flags &= ~AUTOFS_INF_PENDING; |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 421 | } |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 422 | done: |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 423 | if (!(ino->flags & AUTOFS_INF_EXPIRING)) { |
| 424 | /* |
| 425 | * Any needed mounting has been completed and the path updated |
| 426 | * so turn this into a normal dentry so we don't continually |
| 427 | * call ->d_automount() and ->d_manage(). |
| 428 | */ |
| 429 | spin_lock(&dentry->d_lock); |
| 430 | __managed_dentry_clear_transit(dentry); |
| 431 | /* |
| 432 | * Only clear DMANAGED_AUTOMOUNT for rootless multi-mounts and |
| 433 | * symlinks as in all other cases the dentry will be covered by |
| 434 | * an actual mount so ->d_automount() won't be called during |
| 435 | * the follow. |
| 436 | */ |
| 437 | if ((!d_mountpoint(dentry) && |
| 438 | !list_empty(&dentry->d_subdirs)) || |
| 439 | (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))) |
| 440 | __managed_dentry_clear_automount(dentry); |
| 441 | spin_unlock(&dentry->d_lock); |
| 442 | } |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 443 | spin_unlock(&sbi->fs_lock); |
| 444 | |
| 445 | /* Mount succeeded, check if we ended up with a new dentry */ |
| 446 | dentry = autofs4_mountpoint_changed(path); |
| 447 | if (!dentry) |
| 448 | return ERR_PTR(-ENOENT); |
| 449 | |
| 450 | return NULL; |
| 451 | } |
| 452 | |
David Howells | ab90911 | 2011-01-14 18:46:51 +0000 | [diff] [blame] | 453 | int autofs4_d_manage(struct dentry *dentry, bool mounting_here, bool rcu_walk) |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 454 | { |
| 455 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| 456 | |
| 457 | DPRINTK("dentry=%p %.*s", |
| 458 | dentry, dentry->d_name.len, dentry->d_name.name); |
| 459 | |
| 460 | /* The daemon never waits. */ |
| 461 | if (autofs4_oz_mode(sbi) || mounting_here) { |
| 462 | if (!d_mountpoint(dentry)) |
| 463 | return -EISDIR; |
| 464 | return 0; |
| 465 | } |
| 466 | |
David Howells | ab90911 | 2011-01-14 18:46:51 +0000 | [diff] [blame] | 467 | /* We need to sleep, so we need pathwalk to be in ref-mode */ |
| 468 | if (rcu_walk) |
| 469 | return -ECHILD; |
| 470 | |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 471 | /* Wait for pending expires */ |
| 472 | do_expire_wait(dentry); |
| 473 | |
| 474 | /* |
| 475 | * This dentry may be under construction so wait on mount |
| 476 | * completion. |
| 477 | */ |
| 478 | return autofs4_mount_wait(dentry); |
| 479 | } |
| 480 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | /* Lookups in the root directory */ |
| 482 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) |
| 483 | { |
| 484 | struct autofs_sb_info *sbi; |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 485 | struct autofs_info *ino; |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 486 | struct dentry *active; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 488 | DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | |
Ian Kent | 718c604 | 2006-03-27 01:14:42 -0800 | [diff] [blame] | 490 | /* File name too long to exist */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | if (dentry->d_name.len > NAME_MAX) |
Ian Kent | 718c604 | 2006-03-27 01:14:42 -0800 | [diff] [blame] | 492 | return ERR_PTR(-ENAMETOOLONG); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | |
| 494 | sbi = autofs4_sbi(dir->i_sb); |
Ian Kent | 718c604 | 2006-03-27 01:14:42 -0800 | [diff] [blame] | 495 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 497 | current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | |
Ian Kent | 6510c9d | 2009-12-15 16:45:47 -0800 | [diff] [blame] | 499 | active = autofs4_lookup_active(dentry); |
Ian Kent | 90387c9 | 2009-12-15 16:45:46 -0800 | [diff] [blame] | 500 | if (active) { |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 501 | return active; |
Ian Kent | aa952eb | 2009-12-15 16:45:45 -0800 | [diff] [blame] | 502 | } else { |
Ian Kent | 71e469d | 2011-01-14 18:46:19 +0000 | [diff] [blame] | 503 | d_set_d_op(dentry, &autofs4_dentry_operations); |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 504 | |
| 505 | /* |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 506 | * A dentry that is not within the root can never trigger a |
| 507 | * mount operation, unless the directory already exists, so we |
| 508 | * can return fail immediately. The daemon however does need |
| 509 | * to create directories within the file system. |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 510 | */ |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 511 | if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
| 512 | return ERR_PTR(-ENOENT); |
| 513 | |
| 514 | /* Mark entries in the root as mount triggers */ |
| 515 | if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent)) { |
Ian Kent | 71e469d | 2011-01-14 18:46:19 +0000 | [diff] [blame] | 516 | d_set_d_op(dentry, &autofs4_mount_dentry_operations); |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 517 | __managed_dentry_set_managed(dentry); |
Ian Kent | 1058421 | 2011-01-14 18:45:58 +0000 | [diff] [blame] | 518 | } |
| 519 | |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 520 | ino = autofs4_init_ino(NULL, sbi, 0555); |
| 521 | if (!ino) |
| 522 | return ERR_PTR(-ENOMEM); |
| 523 | |
| 524 | dentry->d_fsdata = ino; |
| 525 | ino->dentry = dentry; |
| 526 | |
| 527 | autofs4_add_active(dentry); |
| 528 | |
| 529 | d_instantiate(dentry, NULL); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 530 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | return NULL; |
| 532 | } |
| 533 | |
| 534 | static int autofs4_dir_symlink(struct inode *dir, |
| 535 | struct dentry *dentry, |
| 536 | const char *symname) |
| 537 | { |
| 538 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
| 539 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 540 | struct autofs_info *p_ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | struct inode *inode; |
| 542 | char *cp; |
| 543 | |
| 544 | DPRINTK("%s <- %.*s", symname, |
| 545 | dentry->d_name.len, dentry->d_name.name); |
| 546 | |
| 547 | if (!autofs4_oz_mode(sbi)) |
| 548 | return -EACCES; |
| 549 | |
| 550 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 551 | if (!ino) |
| 552 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 554 | autofs4_del_active(dentry); |
| 555 | |
Ian Kent | ef581a7 | 2008-07-23 21:30:13 -0700 | [diff] [blame] | 556 | ino->size = strlen(symname); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 557 | cp = kmalloc(ino->size + 1, GFP_KERNEL); |
| 558 | if (!cp) { |
| 559 | if (!dentry->d_fsdata) |
| 560 | kfree(ino); |
| 561 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | } |
| 563 | |
| 564 | strcpy(cp, symname); |
| 565 | |
| 566 | inode = autofs4_get_inode(dir->i_sb, ino); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 567 | if (!inode) { |
| 568 | kfree(cp); |
| 569 | if (!dentry->d_fsdata) |
| 570 | kfree(ino); |
| 571 | return -ENOMEM; |
| 572 | } |
Ian Kent | 1864f7b | 2007-08-22 14:01:54 -0700 | [diff] [blame] | 573 | d_add(dentry, inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | |
Ian Kent | 71e469d | 2011-01-14 18:46:19 +0000 | [diff] [blame] | 575 | d_set_d_op(dentry, &autofs4_dentry_operations); |
| 576 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | dentry->d_fsdata = ino; |
| 578 | ino->dentry = dget(dentry); |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 579 | atomic_inc(&ino->count); |
| 580 | p_ino = autofs4_dentry_ino(dentry->d_parent); |
| 581 | if (p_ino && dentry->d_parent != dentry) |
| 582 | atomic_inc(&p_ino->count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 584 | ino->u.symlink = cp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | dir->i_mtime = CURRENT_TIME; |
| 586 | |
| 587 | return 0; |
| 588 | } |
| 589 | |
| 590 | /* |
| 591 | * NOTE! |
| 592 | * |
| 593 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache |
| 594 | * that the file no longer exists. However, doing that means that the |
| 595 | * VFS layer can turn the dentry into a negative dentry. We don't want |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 596 | * this, because the unlink is probably the result of an expire. |
Ian Kent | 5f6f4f2 | 2008-07-23 21:30:09 -0700 | [diff] [blame] | 597 | * We simply d_drop it and add it to a expiring list in the super block, |
| 598 | * which allows the dentry lookup to check for an incomplete expire. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | * |
| 600 | * If a process is blocked on the dentry waiting for the expire to finish, |
| 601 | * it will invalidate the dentry and try to mount with a new one. |
| 602 | * |
| 603 | * Also see autofs4_dir_rmdir().. |
| 604 | */ |
| 605 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) |
| 606 | { |
| 607 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
| 608 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 609 | struct autofs_info *p_ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 610 | |
| 611 | /* This allows root to remove symlinks */ |
Sukadev Bhattiprolu | d78e53c | 2007-05-10 22:23:06 -0700 | [diff] [blame] | 612 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | return -EACCES; |
| 614 | |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 615 | if (atomic_dec_and_test(&ino->count)) { |
| 616 | p_ino = autofs4_dentry_ino(dentry->d_parent); |
| 617 | if (p_ino && dentry->d_parent != dentry) |
| 618 | atomic_dec(&p_ino->count); |
| 619 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | dput(ino->dentry); |
| 621 | |
| 622 | dentry->d_inode->i_size = 0; |
Dave Hansen | ce71ec3 | 2006-09-30 23:29:06 -0700 | [diff] [blame] | 623 | clear_nlink(dentry->d_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | |
| 625 | dir->i_mtime = CURRENT_TIME; |
| 626 | |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 627 | spin_lock(&autofs4_lock); |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 628 | autofs4_add_expiring(dentry); |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 629 | spin_lock(&dentry->d_lock); |
| 630 | __d_drop(dentry); |
| 631 | spin_unlock(&dentry->d_lock); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 632 | spin_unlock(&autofs4_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | |
| 634 | return 0; |
| 635 | } |
| 636 | |
Ian Kent | dd89f90 | 2011-01-14 18:46:35 +0000 | [diff] [blame] | 637 | /* |
| 638 | * Version 4 of autofs provides a pseudo direct mount implementation |
| 639 | * that relies on directories at the leaves of a directory tree under |
| 640 | * an indirect mount to trigger mounts. To allow for this we need to |
| 641 | * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves |
| 642 | * of the directory tree. There is no need to clear the automount flag |
| 643 | * following a mount or restore it after an expire because these mounts |
| 644 | * are always covered. However, it is neccessary to ensure that these |
| 645 | * flags are clear on non-empty directories to avoid unnecessary calls |
| 646 | * during path walks. |
| 647 | */ |
| 648 | static void autofs_set_leaf_automount_flags(struct dentry *dentry) |
| 649 | { |
| 650 | struct dentry *parent; |
| 651 | |
| 652 | /* root and dentrys in the root are already handled */ |
| 653 | if (IS_ROOT(dentry->d_parent)) |
| 654 | return; |
| 655 | |
| 656 | managed_dentry_set_managed(dentry); |
| 657 | |
| 658 | parent = dentry->d_parent; |
| 659 | /* only consider parents below dentrys in the root */ |
| 660 | if (IS_ROOT(parent->d_parent)) |
| 661 | return; |
| 662 | managed_dentry_clear_managed(parent); |
| 663 | return; |
| 664 | } |
| 665 | |
| 666 | static void autofs_clear_leaf_automount_flags(struct dentry *dentry) |
| 667 | { |
| 668 | struct list_head *d_child; |
| 669 | struct dentry *parent; |
| 670 | |
| 671 | /* flags for dentrys in the root are handled elsewhere */ |
| 672 | if (IS_ROOT(dentry->d_parent)) |
| 673 | return; |
| 674 | |
| 675 | managed_dentry_clear_managed(dentry); |
| 676 | |
| 677 | parent = dentry->d_parent; |
| 678 | /* only consider parents below dentrys in the root */ |
| 679 | if (IS_ROOT(parent->d_parent)) |
| 680 | return; |
| 681 | d_child = &dentry->d_u.d_child; |
| 682 | /* Set parent managed if it's becoming empty */ |
| 683 | if (d_child->next == &parent->d_subdirs && |
| 684 | d_child->prev == &parent->d_subdirs) |
| 685 | managed_dentry_set_managed(parent); |
| 686 | return; |
| 687 | } |
| 688 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) |
| 690 | { |
| 691 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
| 692 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 693 | struct autofs_info *p_ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | |
Ian Kent | f50b6f8 | 2007-02-20 13:58:10 -0800 | [diff] [blame] | 695 | DPRINTK("dentry %p, removing %.*s", |
| 696 | dentry, dentry->d_name.len, dentry->d_name.name); |
| 697 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | if (!autofs4_oz_mode(sbi)) |
| 699 | return -EACCES; |
| 700 | |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 701 | spin_lock(&autofs4_lock); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 702 | spin_lock(&sbi->lookup_lock); |
| 703 | spin_lock(&dentry->d_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | if (!list_empty(&dentry->d_subdirs)) { |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 705 | spin_unlock(&dentry->d_lock); |
| 706 | spin_unlock(&sbi->lookup_lock); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 707 | spin_unlock(&autofs4_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | return -ENOTEMPTY; |
| 709 | } |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 710 | __autofs4_add_expiring(dentry); |
| 711 | spin_unlock(&sbi->lookup_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | __d_drop(dentry); |
| 713 | spin_unlock(&dentry->d_lock); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 714 | spin_unlock(&autofs4_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 715 | |
Ian Kent | dd89f90 | 2011-01-14 18:46:35 +0000 | [diff] [blame] | 716 | if (sbi->version < 5) |
| 717 | autofs_clear_leaf_automount_flags(dentry); |
| 718 | |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 719 | if (atomic_dec_and_test(&ino->count)) { |
| 720 | p_ino = autofs4_dentry_ino(dentry->d_parent); |
| 721 | if (p_ino && dentry->d_parent != dentry) |
| 722 | atomic_dec(&p_ino->count); |
| 723 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | dput(ino->dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | dentry->d_inode->i_size = 0; |
Dave Hansen | ce71ec3 | 2006-09-30 23:29:06 -0700 | [diff] [blame] | 726 | clear_nlink(dentry->d_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 727 | |
| 728 | if (dir->i_nlink) |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 729 | drop_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 730 | |
| 731 | return 0; |
| 732 | } |
| 733 | |
| 734 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) |
| 735 | { |
| 736 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
| 737 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 738 | struct autofs_info *p_ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | struct inode *inode; |
| 740 | |
Sukadev Bhattiprolu | d78e53c | 2007-05-10 22:23:06 -0700 | [diff] [blame] | 741 | if (!autofs4_oz_mode(sbi)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | return -EACCES; |
| 743 | |
| 744 | DPRINTK("dentry %p, creating %.*s", |
| 745 | dentry, dentry->d_name.len, dentry->d_name.name); |
| 746 | |
| 747 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 748 | if (!ino) |
| 749 | return -ENOMEM; |
| 750 | |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 751 | autofs4_del_active(dentry); |
| 752 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | inode = autofs4_get_inode(dir->i_sb, ino); |
Ian Kent | 2576737 | 2008-07-23 21:30:12 -0700 | [diff] [blame] | 754 | if (!inode) { |
| 755 | if (!dentry->d_fsdata) |
| 756 | kfree(ino); |
| 757 | return -ENOMEM; |
| 758 | } |
Ian Kent | 1864f7b | 2007-08-22 14:01:54 -0700 | [diff] [blame] | 759 | d_add(dentry, inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | |
Ian Kent | dd89f90 | 2011-01-14 18:46:35 +0000 | [diff] [blame] | 761 | if (sbi->version < 5) |
| 762 | autofs_set_leaf_automount_flags(dentry); |
| 763 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | dentry->d_fsdata = ino; |
| 765 | ino->dentry = dget(dentry); |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 766 | atomic_inc(&ino->count); |
| 767 | p_ino = autofs4_dentry_ino(dentry->d_parent); |
| 768 | if (p_ino && dentry->d_parent != dentry) |
| 769 | atomic_inc(&p_ino->count); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 770 | inc_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | dir->i_mtime = CURRENT_TIME; |
| 772 | |
| 773 | return 0; |
| 774 | } |
| 775 | |
| 776 | /* Get/set timeout ioctl() operation */ |
Arnd Bergmann | c9243f5 | 2010-07-04 00:15:07 +0200 | [diff] [blame] | 777 | #ifdef CONFIG_COMPAT |
| 778 | static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, |
| 779 | compat_ulong_t __user *p) |
| 780 | { |
| 781 | int rv; |
| 782 | unsigned long ntimeout; |
| 783 | |
| 784 | if ((rv = get_user(ntimeout, p)) || |
| 785 | (rv = put_user(sbi->exp_timeout/HZ, p))) |
| 786 | return rv; |
| 787 | |
| 788 | if (ntimeout > UINT_MAX/HZ) |
| 789 | sbi->exp_timeout = 0; |
| 790 | else |
| 791 | sbi->exp_timeout = ntimeout * HZ; |
| 792 | |
| 793 | return 0; |
| 794 | } |
| 795 | #endif |
| 796 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 797 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
| 798 | unsigned long __user *p) |
| 799 | { |
| 800 | int rv; |
| 801 | unsigned long ntimeout; |
| 802 | |
Sukadev Bhattiprolu | d78e53c | 2007-05-10 22:23:06 -0700 | [diff] [blame] | 803 | if ((rv = get_user(ntimeout, p)) || |
| 804 | (rv = put_user(sbi->exp_timeout/HZ, p))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | return rv; |
| 806 | |
Sukadev Bhattiprolu | d78e53c | 2007-05-10 22:23:06 -0700 | [diff] [blame] | 807 | if (ntimeout > ULONG_MAX/HZ) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | sbi->exp_timeout = 0; |
| 809 | else |
| 810 | sbi->exp_timeout = ntimeout * HZ; |
| 811 | |
| 812 | return 0; |
| 813 | } |
| 814 | |
| 815 | /* Return protocol version */ |
| 816 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) |
| 817 | { |
| 818 | return put_user(sbi->version, p); |
| 819 | } |
| 820 | |
| 821 | /* Return protocol sub version */ |
| 822 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) |
| 823 | { |
| 824 | return put_user(sbi->sub_version, p); |
| 825 | } |
| 826 | |
| 827 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 828 | * Tells the daemon whether it can umount the autofs mount. |
| 829 | */ |
| 830 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) |
| 831 | { |
| 832 | int status = 0; |
| 833 | |
Ian Kent | e3474a8 | 2006-03-27 01:14:51 -0800 | [diff] [blame] | 834 | if (may_umount(mnt)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | status = 1; |
| 836 | |
| 837 | DPRINTK("returning %d", status); |
| 838 | |
| 839 | status = put_user(status, p); |
| 840 | |
| 841 | return status; |
| 842 | } |
| 843 | |
| 844 | /* Identify autofs4_dentries - this is so we can tell if there's |
| 845 | an extra dentry refcount or not. We only hold a refcount on the |
| 846 | dentry if its non-negative (ie, d_inode != NULL) |
| 847 | */ |
| 848 | int is_autofs4_dentry(struct dentry *dentry) |
| 849 | { |
| 850 | return dentry && dentry->d_inode && |
Ian Kent | 71e469d | 2011-01-14 18:46:19 +0000 | [diff] [blame] | 851 | (dentry->d_op == &autofs4_mount_dentry_operations || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | dentry->d_op == &autofs4_dentry_operations) && |
| 853 | dentry->d_fsdata != NULL; |
| 854 | } |
| 855 | |
| 856 | /* |
| 857 | * ioctl()'s on the root directory is the chief method for the daemon to |
| 858 | * generate kernel reactions |
| 859 | */ |
Frederic Weisbecker | 3663df7 | 2010-05-19 15:08:17 +0200 | [diff] [blame] | 860 | static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
| 861 | unsigned int cmd, unsigned long arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | { |
| 863 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); |
| 864 | void __user *p = (void __user *)arg; |
| 865 | |
| 866 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", |
Pavel Emelianov | a47afb0 | 2007-10-18 23:39:46 -0700 | [diff] [blame] | 867 | cmd,arg,sbi,task_pgrp_nr(current)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | |
Sukadev Bhattiprolu | d78e53c | 2007-05-10 22:23:06 -0700 | [diff] [blame] | 869 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
| 870 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | return -ENOTTY; |
| 872 | |
Sukadev Bhattiprolu | d78e53c | 2007-05-10 22:23:06 -0700 | [diff] [blame] | 873 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 874 | return -EPERM; |
| 875 | |
| 876 | switch(cmd) { |
| 877 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ |
| 878 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); |
| 879 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ |
| 880 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); |
| 881 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ |
| 882 | autofs4_catatonic_mode(sbi); |
| 883 | return 0; |
| 884 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ |
| 885 | return autofs4_get_protover(sbi, p); |
| 886 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ |
| 887 | return autofs4_get_protosubver(sbi, p); |
| 888 | case AUTOFS_IOC_SETTIMEOUT: |
| 889 | return autofs4_get_set_timeout(sbi, p); |
Arnd Bergmann | c9243f5 | 2010-07-04 00:15:07 +0200 | [diff] [blame] | 890 | #ifdef CONFIG_COMPAT |
| 891 | case AUTOFS_IOC_SETTIMEOUT32: |
| 892 | return autofs4_compat_get_set_timeout(sbi, p); |
| 893 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 894 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 895 | case AUTOFS_IOC_ASKUMOUNT: |
Josef "Jeff" Sipek | a4669ed | 2006-12-08 02:36:46 -0800 | [diff] [blame] | 896 | return autofs4_ask_umount(filp->f_path.mnt, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | |
| 898 | /* return a single thing to expire */ |
| 899 | case AUTOFS_IOC_EXPIRE: |
Josef "Jeff" Sipek | a4669ed | 2006-12-08 02:36:46 -0800 | [diff] [blame] | 900 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | /* same as above, but can send multiple expires through pipe */ |
| 902 | case AUTOFS_IOC_EXPIRE_MULTI: |
Josef "Jeff" Sipek | a4669ed | 2006-12-08 02:36:46 -0800 | [diff] [blame] | 903 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 904 | |
| 905 | default: |
| 906 | return -ENOSYS; |
| 907 | } |
| 908 | } |
Frederic Weisbecker | 3663df7 | 2010-05-19 15:08:17 +0200 | [diff] [blame] | 909 | |
| 910 | static long autofs4_root_ioctl(struct file *filp, |
| 911 | unsigned int cmd, unsigned long arg) |
| 912 | { |
Frederic Weisbecker | 3663df7 | 2010-05-19 15:08:17 +0200 | [diff] [blame] | 913 | struct inode *inode = filp->f_dentry->d_inode; |
Ian Kent | de47de7 | 2010-12-07 13:04:00 +0800 | [diff] [blame] | 914 | return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
Frederic Weisbecker | 3663df7 | 2010-05-19 15:08:17 +0200 | [diff] [blame] | 915 | } |
Arnd Bergmann | c9243f5 | 2010-07-04 00:15:07 +0200 | [diff] [blame] | 916 | |
| 917 | #ifdef CONFIG_COMPAT |
| 918 | static long autofs4_root_compat_ioctl(struct file *filp, |
| 919 | unsigned int cmd, unsigned long arg) |
| 920 | { |
| 921 | struct inode *inode = filp->f_path.dentry->d_inode; |
| 922 | int ret; |
| 923 | |
Arnd Bergmann | c9243f5 | 2010-07-04 00:15:07 +0200 | [diff] [blame] | 924 | if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
| 925 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
| 926 | else |
| 927 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, |
| 928 | (unsigned long)compat_ptr(arg)); |
Arnd Bergmann | c9243f5 | 2010-07-04 00:15:07 +0200 | [diff] [blame] | 929 | |
| 930 | return ret; |
| 931 | } |
| 932 | #endif |