Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* -*- c -*- --------------------------------------------------------------- * |
| 2 | * |
| 3 | * linux/fs/autofs/expire.c |
| 4 | * |
| 5 | * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved |
| 6 | * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -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 | |
| 15 | #include "autofs_i.h" |
| 16 | |
| 17 | static unsigned long now; |
| 18 | |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 19 | /* Check if a dentry can be expired */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | static inline int autofs4_can_expire(struct dentry *dentry, |
| 21 | unsigned long timeout, int do_now) |
| 22 | { |
| 23 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| 24 | |
| 25 | /* dentry in the process of being deleted */ |
| 26 | if (ino == NULL) |
| 27 | return 0; |
| 28 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | if (!do_now) { |
| 30 | /* Too young to die */ |
Ian Kent | c0ba7e5 | 2006-09-25 16:24:16 -0700 | [diff] [blame] | 31 | if (!timeout || time_after(ino->last_used + timeout, now)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | return 0; |
| 33 | |
| 34 | /* update last_used here :- |
| 35 | - obviously makes sense if it is in use now |
| 36 | - less obviously, prevents rapid-fire expire |
| 37 | attempts if expire fails the first time */ |
| 38 | ino->last_used = now; |
| 39 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | return 1; |
| 41 | } |
| 42 | |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 43 | /* Check a mount point for busyness */ |
| 44 | static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | { |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 46 | struct dentry *top = dentry; |
Al Viro | 9393bd0 | 2009-04-18 13:58:15 -0400 | [diff] [blame] | 47 | struct path path = {.mnt = mnt, .dentry = dentry}; |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 48 | int status = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
| 50 | DPRINTK("dentry %p %.*s", |
| 51 | dentry, (int)dentry->d_name.len, dentry->d_name.name); |
| 52 | |
Al Viro | 9393bd0 | 2009-04-18 13:58:15 -0400 | [diff] [blame] | 53 | path_get(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
David Howells | cc53ce5 | 2011-01-14 18:45:26 +0000 | [diff] [blame] | 55 | if (!follow_down_one(&path)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | goto done; |
| 57 | |
Al Viro | 9393bd0 | 2009-04-18 13:58:15 -0400 | [diff] [blame] | 58 | if (is_autofs4_dentry(path.dentry)) { |
| 59 | struct autofs_sb_info *sbi = autofs4_sbi(path.dentry->d_sb); |
Ian Kent | bc9c406 | 2008-11-06 12:53:22 -0800 | [diff] [blame] | 60 | |
| 61 | /* This is an autofs submount, we can't expire it */ |
Ian Kent | a92daf6 | 2009-01-06 14:42:08 -0800 | [diff] [blame] | 62 | if (autofs_type_indirect(sbi->type)) |
Ian Kent | bc9c406 | 2008-11-06 12:53:22 -0800 | [diff] [blame] | 63 | goto done; |
Ian Kent | bc9c406 | 2008-11-06 12:53:22 -0800 | [diff] [blame] | 64 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 66 | /* Update the expiry counter if fs is busy */ |
Ian Kent | 37d0892 | 2009-09-01 11:26:22 +0800 | [diff] [blame] | 67 | if (!may_umount_tree(path.mnt)) { |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 68 | struct autofs_info *ino = autofs4_dentry_ino(top); |
| 69 | ino->last_used = jiffies; |
| 70 | goto done; |
| 71 | } |
| 72 | |
| 73 | status = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | done: |
| 75 | DPRINTK("returning = %d", status); |
Al Viro | 9393bd0 | 2009-04-18 13:58:15 -0400 | [diff] [blame] | 76 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | return status; |
| 78 | } |
| 79 | |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 80 | /* |
Ian Kent | d4a85e3 | 2011-03-25 01:51:20 +0800 | [diff] [blame] | 81 | * Calculate and dget next entry in the subdirs list under root. |
| 82 | */ |
| 83 | static struct dentry *get_next_positive_subdir(struct dentry *prev, |
| 84 | struct dentry *root) |
| 85 | { |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 86 | struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb); |
Ian Kent | d4a85e3 | 2011-03-25 01:51:20 +0800 | [diff] [blame] | 87 | struct list_head *next; |
| 88 | struct dentry *p, *q; |
| 89 | |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 90 | spin_lock(&sbi->lookup_lock); |
Ian Kent | d4a85e3 | 2011-03-25 01:51:20 +0800 | [diff] [blame] | 91 | |
| 92 | if (prev == NULL) { |
| 93 | spin_lock(&root->d_lock); |
| 94 | prev = dget_dlock(root); |
| 95 | next = prev->d_subdirs.next; |
| 96 | p = prev; |
| 97 | goto start; |
| 98 | } |
| 99 | |
| 100 | p = prev; |
| 101 | spin_lock(&p->d_lock); |
| 102 | again: |
Al Viro | a7cca09 | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 103 | next = p->d_child.next; |
Ian Kent | d4a85e3 | 2011-03-25 01:51:20 +0800 | [diff] [blame] | 104 | start: |
| 105 | if (next == &root->d_subdirs) { |
| 106 | spin_unlock(&p->d_lock); |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 107 | spin_unlock(&sbi->lookup_lock); |
Ian Kent | d4a85e3 | 2011-03-25 01:51:20 +0800 | [diff] [blame] | 108 | dput(prev); |
| 109 | return NULL; |
| 110 | } |
| 111 | |
Al Viro | a7cca09 | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 112 | q = list_entry(next, struct dentry, d_child); |
Ian Kent | d4a85e3 | 2011-03-25 01:51:20 +0800 | [diff] [blame] | 113 | |
| 114 | spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED); |
| 115 | /* Negative dentry - try next */ |
| 116 | if (!simple_positive(q)) { |
| 117 | spin_unlock(&p->d_lock); |
Steven Rostedt | 1d6f209 | 2011-08-22 11:52:28 +0800 | [diff] [blame] | 118 | lock_set_subclass(&q->d_lock.dep_map, 0, _RET_IP_); |
Ian Kent | d4a85e3 | 2011-03-25 01:51:20 +0800 | [diff] [blame] | 119 | p = q; |
| 120 | goto again; |
| 121 | } |
| 122 | dget_dlock(q); |
| 123 | spin_unlock(&q->d_lock); |
| 124 | spin_unlock(&p->d_lock); |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 125 | spin_unlock(&sbi->lookup_lock); |
Ian Kent | d4a85e3 | 2011-03-25 01:51:20 +0800 | [diff] [blame] | 126 | |
| 127 | dput(prev); |
| 128 | |
| 129 | return q; |
| 130 | } |
| 131 | |
| 132 | /* |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 133 | * Calculate and dget next entry in top down tree traversal. |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 134 | */ |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 135 | static struct dentry *get_next_positive_dentry(struct dentry *prev, |
| 136 | struct dentry *root) |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 137 | { |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 138 | struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 139 | struct list_head *next; |
| 140 | struct dentry *p, *ret; |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 141 | |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 142 | if (prev == NULL) |
Ian Kent | c14cc63 | 2011-01-18 12:06:04 +0800 | [diff] [blame] | 143 | return dget(root); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 144 | |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 145 | spin_lock(&sbi->lookup_lock); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 146 | relock: |
| 147 | p = prev; |
| 148 | spin_lock(&p->d_lock); |
| 149 | again: |
| 150 | next = p->d_subdirs.next; |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 151 | if (next == &p->d_subdirs) { |
| 152 | while (1) { |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 153 | struct dentry *parent; |
| 154 | |
| 155 | if (p == root) { |
| 156 | spin_unlock(&p->d_lock); |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 157 | spin_unlock(&sbi->lookup_lock); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 158 | dput(prev); |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 159 | return NULL; |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 160 | } |
| 161 | |
| 162 | parent = p->d_parent; |
| 163 | if (!spin_trylock(&parent->d_lock)) { |
| 164 | spin_unlock(&p->d_lock); |
| 165 | cpu_relax(); |
| 166 | goto relock; |
| 167 | } |
| 168 | spin_unlock(&p->d_lock); |
Al Viro | a7cca09 | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 169 | next = p->d_child.next; |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 170 | p = parent; |
| 171 | if (next != &parent->d_subdirs) |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 172 | break; |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 173 | } |
| 174 | } |
Al Viro | a7cca09 | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 175 | ret = list_entry(next, struct dentry, d_child); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 176 | |
| 177 | spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED); |
| 178 | /* Negative dentry - try next */ |
| 179 | if (!simple_positive(ret)) { |
Ian Kent | c14cc63 | 2011-01-18 12:06:04 +0800 | [diff] [blame] | 180 | spin_unlock(&p->d_lock); |
Steven Rostedt | 1d6f209 | 2011-08-22 11:52:28 +0800 | [diff] [blame] | 181 | lock_set_subclass(&ret->d_lock.dep_map, 0, _RET_IP_); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 182 | p = ret; |
| 183 | goto again; |
| 184 | } |
| 185 | dget_dlock(ret); |
| 186 | spin_unlock(&ret->d_lock); |
| 187 | spin_unlock(&p->d_lock); |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 188 | spin_unlock(&sbi->lookup_lock); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 189 | |
| 190 | dput(prev); |
| 191 | |
| 192 | return ret; |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 193 | } |
| 194 | |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 195 | /* |
| 196 | * Check a direct mount point for busyness. |
| 197 | * Direct mounts have similar expiry semantics to tree mounts. |
| 198 | * The tree is not busy iff no mountpoints are busy and there are no |
| 199 | * autofs submounts. |
| 200 | */ |
| 201 | static int autofs4_direct_busy(struct vfsmount *mnt, |
| 202 | struct dentry *top, |
| 203 | unsigned long timeout, |
| 204 | int do_now) |
| 205 | { |
| 206 | DPRINTK("top %p %.*s", |
| 207 | top, (int) top->d_name.len, top->d_name.name); |
| 208 | |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 209 | /* If it's busy update the expiry counters */ |
| 210 | if (!may_umount_tree(mnt)) { |
| 211 | struct autofs_info *ino = autofs4_dentry_ino(top); |
| 212 | if (ino) |
| 213 | ino->last_used = jiffies; |
| 214 | return 1; |
| 215 | } |
| 216 | |
| 217 | /* Timeout of a direct mount is determined by its top dentry */ |
| 218 | if (!autofs4_can_expire(top, timeout, do_now)) |
| 219 | return 1; |
| 220 | |
| 221 | return 0; |
| 222 | } |
| 223 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | /* Check a directory tree of mount points for busyness |
| 225 | * The tree is not busy iff no mountpoints are busy |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | */ |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 227 | static int autofs4_tree_busy(struct vfsmount *mnt, |
| 228 | struct dentry *top, |
| 229 | unsigned long timeout, |
| 230 | int do_now) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | { |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 232 | struct autofs_info *top_ino = autofs4_dentry_ino(top); |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 233 | struct dentry *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 235 | DPRINTK("top %p %.*s", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | top, (int)top->d_name.len, top->d_name.name); |
| 237 | |
| 238 | /* Negative dentry - give up */ |
| 239 | if (!simple_positive(top)) |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 240 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 242 | p = NULL; |
| 243 | while ((p = get_next_positive_dentry(p, top))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | DPRINTK("dentry %p %.*s", |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 245 | p, (int) p->d_name.len, p->d_name.name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 247 | /* |
| 248 | * Is someone visiting anywhere in the subtree ? |
| 249 | * If there's no mount we need to check the usage |
| 250 | * count for the autofs dentry. |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 251 | * If the fs is busy update the expiry counter. |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 252 | */ |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 253 | if (d_mountpoint(p)) { |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 254 | if (autofs4_mount_busy(mnt, p)) { |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 255 | top_ino->last_used = jiffies; |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 256 | dput(p); |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 257 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | } |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 259 | } else { |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 260 | struct autofs_info *ino = autofs4_dentry_ino(p); |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 261 | unsigned int ino_count = atomic_read(&ino->count); |
| 262 | |
Ian Kent | f9022f6 | 2006-06-25 05:48:47 -0700 | [diff] [blame] | 263 | /* |
| 264 | * Clean stale dentries below that have not been |
| 265 | * invalidated after a mount fail during lookup |
| 266 | */ |
| 267 | d_invalidate(p); |
| 268 | |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 269 | /* allow for dget above and top is already dgot */ |
| 270 | if (p == top) |
| 271 | ino_count += 2; |
| 272 | else |
| 273 | ino_count++; |
| 274 | |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 275 | if (p->d_count > ino_count) { |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 276 | top_ino->last_used = jiffies; |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 277 | dput(p); |
| 278 | return 1; |
| 279 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | } |
Ian Kent | 1aff3c8 | 2006-03-27 01:14:46 -0800 | [diff] [blame] | 282 | |
| 283 | /* Timeout of a tree mount is ultimately determined by its top dentry */ |
| 284 | if (!autofs4_can_expire(top, timeout, do_now)) |
| 285 | return 1; |
| 286 | |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 287 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | } |
| 289 | |
| 290 | static struct dentry *autofs4_check_leaves(struct vfsmount *mnt, |
| 291 | struct dentry *parent, |
| 292 | unsigned long timeout, |
| 293 | int do_now) |
| 294 | { |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 295 | struct dentry *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | |
| 297 | DPRINTK("parent %p %.*s", |
| 298 | parent, (int)parent->d_name.len, parent->d_name.name); |
| 299 | |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 300 | p = NULL; |
| 301 | while ((p = get_next_positive_dentry(p, parent))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | DPRINTK("dentry %p %.*s", |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 303 | p, (int) p->d_name.len, p->d_name.name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 305 | if (d_mountpoint(p)) { |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 306 | /* Can we umount this guy */ |
| 307 | if (autofs4_mount_busy(mnt, p)) |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 308 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 310 | /* Can we expire this guy */ |
| 311 | if (autofs4_can_expire(p, timeout, do_now)) |
Ian Kent | 1ce12ba | 2006-03-27 01:14:45 -0800 | [diff] [blame] | 312 | return p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | return NULL; |
| 316 | } |
| 317 | |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 318 | /* Check if we can expire a direct mount (possibly a tree) */ |
Ian Kent | 8d7b48e | 2008-10-15 22:02:54 -0700 | [diff] [blame] | 319 | struct dentry *autofs4_expire_direct(struct super_block *sb, |
| 320 | struct vfsmount *mnt, |
| 321 | struct autofs_sb_info *sbi, |
| 322 | int how) |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 323 | { |
| 324 | unsigned long timeout; |
| 325 | struct dentry *root = dget(sb->s_root); |
| 326 | int do_now = how & AUTOFS_EXP_IMMEDIATE; |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 327 | struct autofs_info *ino; |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 328 | |
Ian Kent | c0ba7e5 | 2006-09-25 16:24:16 -0700 | [diff] [blame] | 329 | if (!root) |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 330 | return NULL; |
| 331 | |
| 332 | now = jiffies; |
| 333 | timeout = sbi->exp_timeout; |
| 334 | |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 335 | spin_lock(&sbi->fs_lock); |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 336 | ino = autofs4_dentry_ino(root); |
| 337 | /* No point expiring a pending mount */ |
Ian Kent | f9398c2 | 2011-03-25 01:51:14 +0800 | [diff] [blame] | 338 | if (ino->flags & AUTOFS_INF_PENDING) |
| 339 | goto out; |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 340 | if (!autofs4_direct_busy(mnt, root, timeout, do_now)) { |
| 341 | struct autofs_info *ino = autofs4_dentry_ino(root); |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 342 | ino->flags |= AUTOFS_INF_EXPIRING; |
Ian Kent | 6e60a9a | 2008-07-23 21:30:27 -0700 | [diff] [blame] | 343 | init_completion(&ino->expire_complete); |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 344 | spin_unlock(&sbi->fs_lock); |
| 345 | return root; |
| 346 | } |
Ian Kent | f9398c2 | 2011-03-25 01:51:14 +0800 | [diff] [blame] | 347 | out: |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 348 | spin_unlock(&sbi->fs_lock); |
| 349 | dput(root); |
| 350 | |
| 351 | return NULL; |
| 352 | } |
| 353 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | /* |
| 355 | * Find an eligible tree to time-out |
| 356 | * A tree is eligible if :- |
| 357 | * - it is unused by any user process |
| 358 | * - it has been unused for exp_timeout time |
| 359 | */ |
Ian Kent | 8d7b48e | 2008-10-15 22:02:54 -0700 | [diff] [blame] | 360 | struct dentry *autofs4_expire_indirect(struct super_block *sb, |
| 361 | struct vfsmount *mnt, |
| 362 | struct autofs_sb_info *sbi, |
| 363 | int how) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | { |
| 365 | unsigned long timeout; |
| 366 | struct dentry *root = sb->s_root; |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 367 | struct dentry *dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | struct dentry *expired = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | int do_now = how & AUTOFS_EXP_IMMEDIATE; |
| 370 | int exp_leaves = how & AUTOFS_EXP_LEAVES; |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 371 | struct autofs_info *ino; |
| 372 | unsigned int ino_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | |
Ian Kent | c0ba7e5 | 2006-09-25 16:24:16 -0700 | [diff] [blame] | 374 | if (!root) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | return NULL; |
| 376 | |
| 377 | now = jiffies; |
| 378 | timeout = sbi->exp_timeout; |
| 379 | |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 380 | dentry = NULL; |
Ian Kent | d4a85e3 | 2011-03-25 01:51:20 +0800 | [diff] [blame] | 381 | while ((dentry = get_next_positive_subdir(dentry, root))) { |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 382 | spin_lock(&sbi->fs_lock); |
| 383 | ino = autofs4_dentry_ino(dentry); |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 384 | /* No point expiring a pending mount */ |
| 385 | if (ino->flags & AUTOFS_INF_PENDING) |
Ian Kent | 3c31998 | 2011-03-25 01:51:08 +0800 | [diff] [blame] | 386 | goto next; |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 387 | |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 388 | /* |
| 389 | * Case 1: (i) indirect mount or top level pseudo direct mount |
| 390 | * (autofs-4.1). |
| 391 | * (ii) indirect mount with offset mount, check the "/" |
| 392 | * offset (autofs-5.0+). |
| 393 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | if (d_mountpoint(dentry)) { |
| 395 | DPRINTK("checking mountpoint %p %.*s", |
| 396 | dentry, (int)dentry->d_name.len, dentry->d_name.name); |
| 397 | |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 398 | /* Path walk currently on this dentry? */ |
| 399 | ino_count = atomic_read(&ino->count) + 2; |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 400 | if (dentry->d_count > ino_count) |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 401 | goto next; |
| 402 | |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 403 | /* Can we umount this guy */ |
| 404 | if (autofs4_mount_busy(mnt, dentry)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | goto next; |
| 406 | |
Ian Kent | e0a7aae | 2006-03-27 01:14:47 -0800 | [diff] [blame] | 407 | /* Can we expire this guy */ |
| 408 | if (autofs4_can_expire(dentry, timeout, do_now)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | expired = dentry; |
Ian Kent | afec570 | 2008-05-01 04:35:06 -0700 | [diff] [blame] | 410 | goto found; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | } |
| 412 | goto next; |
| 413 | } |
| 414 | |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 415 | if (simple_empty(dentry)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | goto next; |
| 417 | |
| 418 | /* Case 2: tree mount, expire iff entire tree is not busy */ |
| 419 | if (!exp_leaves) { |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 420 | /* Path walk currently on this dentry? */ |
| 421 | ino_count = atomic_read(&ino->count) + 1; |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 422 | if (dentry->d_count > ino_count) |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 423 | goto next; |
Ian Kent | 3a9720c | 2005-05-01 08:59:17 -0700 | [diff] [blame] | 424 | |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 425 | if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) { |
Ian Kent | 3a9720c | 2005-05-01 08:59:17 -0700 | [diff] [blame] | 426 | expired = dentry; |
Ian Kent | afec570 | 2008-05-01 04:35:06 -0700 | [diff] [blame] | 427 | goto found; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | } |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 429 | /* |
| 430 | * Case 3: pseudo direct mount, expire individual leaves |
| 431 | * (autofs-4.1). |
| 432 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | } else { |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 434 | /* Path walk currently on this dentry? */ |
| 435 | ino_count = atomic_read(&ino->count) + 1; |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 436 | if (dentry->d_count > ino_count) |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 437 | goto next; |
| 438 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | expired = autofs4_check_leaves(mnt, dentry, timeout, do_now); |
| 440 | if (expired) { |
| 441 | dput(dentry); |
Ian Kent | afec570 | 2008-05-01 04:35:06 -0700 | [diff] [blame] | 442 | goto found; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | } |
| 444 | } |
| 445 | next: |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 446 | spin_unlock(&sbi->fs_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | return NULL; |
Ian Kent | afec570 | 2008-05-01 04:35:06 -0700 | [diff] [blame] | 449 | |
| 450 | found: |
| 451 | DPRINTK("returning %p %.*s", |
| 452 | expired, (int)expired->d_name.len, expired->d_name.name); |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 453 | ino = autofs4_dentry_ino(expired); |
| 454 | ino->flags |= AUTOFS_INF_EXPIRING; |
Ian Kent | 6e60a9a | 2008-07-23 21:30:27 -0700 | [diff] [blame] | 455 | init_completion(&ino->expire_complete); |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 456 | spin_unlock(&sbi->fs_lock); |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 457 | spin_lock(&sbi->lookup_lock); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 458 | spin_lock(&expired->d_parent->d_lock); |
| 459 | spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED); |
Al Viro | a7cca09 | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 460 | list_move(&expired->d_parent->d_subdirs, &expired->d_child); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 461 | spin_unlock(&expired->d_lock); |
| 462 | spin_unlock(&expired->d_parent->d_lock); |
Ian Kent | e785472 | 2011-03-25 01:51:31 +0800 | [diff] [blame] | 463 | spin_unlock(&sbi->lookup_lock); |
Ian Kent | afec570 | 2008-05-01 04:35:06 -0700 | [diff] [blame] | 464 | return expired; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | } |
| 466 | |
Ian Kent | 06a3598 | 2008-07-23 21:30:28 -0700 | [diff] [blame] | 467 | int autofs4_expire_wait(struct dentry *dentry) |
| 468 | { |
| 469 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| 470 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| 471 | int status; |
| 472 | |
| 473 | /* Block on any pending expire */ |
| 474 | spin_lock(&sbi->fs_lock); |
| 475 | if (ino->flags & AUTOFS_INF_EXPIRING) { |
| 476 | spin_unlock(&sbi->fs_lock); |
| 477 | |
| 478 | DPRINTK("waiting for expire %p name=%.*s", |
| 479 | dentry, dentry->d_name.len, dentry->d_name.name); |
| 480 | |
| 481 | status = autofs4_wait(sbi, dentry, NFY_NONE); |
| 482 | wait_for_completion(&ino->expire_complete); |
| 483 | |
| 484 | DPRINTK("expire done status=%d", status); |
| 485 | |
Al Viro | 4b1ae27 | 2010-03-03 12:58:31 -0500 | [diff] [blame] | 486 | if (d_unhashed(dentry)) |
Ian Kent | 06a3598 | 2008-07-23 21:30:28 -0700 | [diff] [blame] | 487 | return -EAGAIN; |
| 488 | |
| 489 | return status; |
| 490 | } |
| 491 | spin_unlock(&sbi->fs_lock); |
| 492 | |
| 493 | return 0; |
| 494 | } |
| 495 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | /* Perform an expiry operation */ |
| 497 | int autofs4_expire_run(struct super_block *sb, |
| 498 | struct vfsmount *mnt, |
| 499 | struct autofs_sb_info *sbi, |
| 500 | struct autofs_packet_expire __user *pkt_p) |
| 501 | { |
| 502 | struct autofs_packet_expire pkt; |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 503 | struct autofs_info *ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | struct dentry *dentry; |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 505 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | |
| 507 | memset(&pkt,0,sizeof pkt); |
| 508 | |
| 509 | pkt.hdr.proto_version = sbi->version; |
| 510 | pkt.hdr.type = autofs_ptype_expire; |
| 511 | |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 512 | if ((dentry = autofs4_expire_indirect(sb, mnt, sbi, 0)) == NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | return -EAGAIN; |
| 514 | |
| 515 | pkt.len = dentry->d_name.len; |
| 516 | memcpy(pkt.name, dentry->d_name.name, pkt.len); |
| 517 | pkt.name[pkt.len] = '\0'; |
| 518 | dput(dentry); |
| 519 | |
| 520 | if ( copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)) ) |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 521 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 523 | spin_lock(&sbi->fs_lock); |
| 524 | ino = autofs4_dentry_ino(dentry); |
| 525 | ino->flags &= ~AUTOFS_INF_EXPIRING; |
Ian Kent | 6e60a9a | 2008-07-23 21:30:27 -0700 | [diff] [blame] | 526 | complete_all(&ino->expire_complete); |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 527 | spin_unlock(&sbi->fs_lock); |
| 528 | |
| 529 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | } |
| 531 | |
Ian Kent | 56fcef7 | 2009-03-31 15:24:43 -0700 | [diff] [blame] | 532 | int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, |
| 533 | struct autofs_sb_info *sbi, int when) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | { |
| 535 | struct dentry *dentry; |
| 536 | int ret = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | |
Ian Kent | a92daf6 | 2009-01-06 14:42:08 -0800 | [diff] [blame] | 538 | if (autofs_type_trigger(sbi->type)) |
Ian Kent | 56fcef7 | 2009-03-31 15:24:43 -0700 | [diff] [blame] | 539 | dentry = autofs4_expire_direct(sb, mnt, sbi, when); |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 540 | else |
Ian Kent | 56fcef7 | 2009-03-31 15:24:43 -0700 | [diff] [blame] | 541 | dentry = autofs4_expire_indirect(sb, mnt, sbi, when); |
Ian Kent | 3a15e2a | 2006-03-27 01:14:55 -0800 | [diff] [blame] | 542 | |
| 543 | if (dentry) { |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 544 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | |
| 546 | /* This is synchronous because it makes the daemon a |
| 547 | little easier */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | ret = autofs4_wait(sbi, dentry, NFY_EXPIRE); |
Ian Kent | 6e60a9a | 2008-07-23 21:30:27 -0700 | [diff] [blame] | 549 | |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 550 | spin_lock(&sbi->fs_lock); |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 551 | ino->flags &= ~AUTOFS_INF_EXPIRING; |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 552 | spin_lock(&dentry->d_lock); |
Ian Kent | 3c31998 | 2011-03-25 01:51:08 +0800 | [diff] [blame] | 553 | if (!ret) { |
Ian Kent | b5b8017 | 2011-01-14 18:46:03 +0000 | [diff] [blame] | 554 | if ((IS_ROOT(dentry) || |
| 555 | (autofs_type_indirect(sbi->type) && |
| 556 | IS_ROOT(dentry->d_parent))) && |
| 557 | !(dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) |
| 558 | __managed_dentry_set_automount(dentry); |
| 559 | } |
| 560 | spin_unlock(&dentry->d_lock); |
Ian Kent | 6e60a9a | 2008-07-23 21:30:27 -0700 | [diff] [blame] | 561 | complete_all(&ino->expire_complete); |
Ian Kent | 97e7449 | 2008-07-23 21:30:26 -0700 | [diff] [blame] | 562 | spin_unlock(&sbi->fs_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | dput(dentry); |
| 564 | } |
Ian Kent | 1f5f2c3 | 2006-03-27 01:14:44 -0800 | [diff] [blame] | 565 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | return ret; |
| 567 | } |
| 568 | |
Ian Kent | 56fcef7 | 2009-03-31 15:24:43 -0700 | [diff] [blame] | 569 | /* Call repeatedly until it returns -EAGAIN, meaning there's nothing |
| 570 | more to be done */ |
| 571 | int autofs4_expire_multi(struct super_block *sb, struct vfsmount *mnt, |
| 572 | struct autofs_sb_info *sbi, int __user *arg) |
| 573 | { |
| 574 | int do_now = 0; |
| 575 | |
| 576 | if (arg && get_user(do_now, arg)) |
| 577 | return -EFAULT; |
| 578 | |
| 579 | return autofs4_do_expire_multi(sb, mnt, sbi, do_now); |
| 580 | } |
| 581 | |