Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * dir.c - Operations for sysfs directories. |
| 3 | */ |
| 4 | |
| 5 | #undef DEBUG |
| 6 | |
| 7 | #include <linux/fs.h> |
| 8 | #include <linux/mount.h> |
| 9 | #include <linux/module.h> |
| 10 | #include <linux/kobject.h> |
Christoph Hellwig | 5f45f1a | 2005-06-23 00:09:12 -0700 | [diff] [blame] | 11 | #include <linux/namei.h> |
Tejun Heo | 2b611bb | 2007-06-14 03:45:13 +0900 | [diff] [blame] | 12 | #include <linux/idr.h> |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 13 | #include <linux/completion.h> |
Oliver Neukum | 94bebf4 | 2006-12-20 10:52:44 +0100 | [diff] [blame] | 14 | #include <asm/semaphore.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include "sysfs.h" |
| 16 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 17 | DEFINE_MUTEX(sysfs_mutex); |
Tejun Heo | 5f99532 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 18 | spinlock_t sysfs_assoc_lock = SPIN_LOCK_UNLOCKED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | |
Tejun Heo | 2b611bb | 2007-06-14 03:45:13 +0900 | [diff] [blame] | 20 | static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED; |
| 21 | static DEFINE_IDA(sysfs_ino_ida); |
| 22 | |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 23 | /** |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 24 | * sysfs_link_sibling - link sysfs_dirent into sibling list |
| 25 | * @sd: sysfs_dirent of interest |
| 26 | * |
| 27 | * Link @sd into its sibling list which starts from |
| 28 | * sd->s_parent->s_children. |
| 29 | * |
| 30 | * Locking: |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 31 | * mutex_lock(sysfs_mutex) |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 32 | */ |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 33 | void sysfs_link_sibling(struct sysfs_dirent *sd) |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 34 | { |
| 35 | struct sysfs_dirent *parent_sd = sd->s_parent; |
| 36 | |
| 37 | BUG_ON(sd->s_sibling); |
| 38 | sd->s_sibling = parent_sd->s_children; |
| 39 | parent_sd->s_children = sd; |
| 40 | } |
| 41 | |
| 42 | /** |
| 43 | * sysfs_unlink_sibling - unlink sysfs_dirent from sibling list |
| 44 | * @sd: sysfs_dirent of interest |
| 45 | * |
| 46 | * Unlink @sd from its sibling list which starts from |
| 47 | * sd->s_parent->s_children. |
| 48 | * |
| 49 | * Locking: |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 50 | * mutex_lock(sysfs_mutex) |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 51 | */ |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 52 | void sysfs_unlink_sibling(struct sysfs_dirent *sd) |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 53 | { |
| 54 | struct sysfs_dirent **pos; |
| 55 | |
| 56 | for (pos = &sd->s_parent->s_children; *pos; pos = &(*pos)->s_sibling) { |
| 57 | if (*pos == sd) { |
| 58 | *pos = sd->s_sibling; |
| 59 | sd->s_sibling = NULL; |
| 60 | break; |
| 61 | } |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | /** |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 66 | * sysfs_get_active - get an active reference to sysfs_dirent |
| 67 | * @sd: sysfs_dirent to get an active reference to |
| 68 | * |
| 69 | * Get an active reference of @sd. This function is noop if @sd |
| 70 | * is NULL. |
| 71 | * |
| 72 | * RETURNS: |
| 73 | * Pointer to @sd on success, NULL on failure. |
| 74 | */ |
| 75 | struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) |
| 76 | { |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 77 | if (unlikely(!sd)) |
| 78 | return NULL; |
| 79 | |
| 80 | while (1) { |
| 81 | int v, t; |
| 82 | |
| 83 | v = atomic_read(&sd->s_active); |
| 84 | if (unlikely(v < 0)) |
| 85 | return NULL; |
| 86 | |
| 87 | t = atomic_cmpxchg(&sd->s_active, v, v + 1); |
| 88 | if (likely(t == v)) |
| 89 | return sd; |
| 90 | if (t < 0) |
| 91 | return NULL; |
| 92 | |
| 93 | cpu_relax(); |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 94 | } |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 95 | } |
| 96 | |
| 97 | /** |
| 98 | * sysfs_put_active - put an active reference to sysfs_dirent |
| 99 | * @sd: sysfs_dirent to put an active reference to |
| 100 | * |
| 101 | * Put an active reference to @sd. This function is noop if @sd |
| 102 | * is NULL. |
| 103 | */ |
| 104 | void sysfs_put_active(struct sysfs_dirent *sd) |
| 105 | { |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 106 | struct completion *cmpl; |
| 107 | int v; |
| 108 | |
| 109 | if (unlikely(!sd)) |
| 110 | return; |
| 111 | |
| 112 | v = atomic_dec_return(&sd->s_active); |
| 113 | if (likely(v != SD_DEACTIVATED_BIAS)) |
| 114 | return; |
| 115 | |
| 116 | /* atomic_dec_return() is a mb(), we'll always see the updated |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 117 | * sd->s_sibling. |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 118 | */ |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 119 | cmpl = (void *)sd->s_sibling; |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 120 | complete(cmpl); |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 121 | } |
| 122 | |
| 123 | /** |
| 124 | * sysfs_get_active_two - get active references to sysfs_dirent and parent |
| 125 | * @sd: sysfs_dirent of interest |
| 126 | * |
| 127 | * Get active reference to @sd and its parent. Parent's active |
| 128 | * reference is grabbed first. This function is noop if @sd is |
| 129 | * NULL. |
| 130 | * |
| 131 | * RETURNS: |
| 132 | * Pointer to @sd on success, NULL on failure. |
| 133 | */ |
| 134 | struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd) |
| 135 | { |
| 136 | if (sd) { |
| 137 | if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent))) |
| 138 | return NULL; |
| 139 | if (unlikely(!sysfs_get_active(sd))) { |
| 140 | sysfs_put_active(sd->s_parent); |
| 141 | return NULL; |
| 142 | } |
| 143 | } |
| 144 | return sd; |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * sysfs_put_active_two - put active references to sysfs_dirent and parent |
| 149 | * @sd: sysfs_dirent of interest |
| 150 | * |
| 151 | * Put active references to @sd and its parent. This function is |
| 152 | * noop if @sd is NULL. |
| 153 | */ |
| 154 | void sysfs_put_active_two(struct sysfs_dirent *sd) |
| 155 | { |
| 156 | if (sd) { |
| 157 | sysfs_put_active(sd); |
| 158 | sysfs_put_active(sd->s_parent); |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * sysfs_deactivate - deactivate sysfs_dirent |
| 164 | * @sd: sysfs_dirent to deactivate |
| 165 | * |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 166 | * Deny new active references and drain existing ones. |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 167 | */ |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 168 | static void sysfs_deactivate(struct sysfs_dirent *sd) |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 169 | { |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 170 | DECLARE_COMPLETION_ONSTACK(wait); |
| 171 | int v; |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 172 | |
Tejun Heo | 380e6fb | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 173 | BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED)); |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 174 | sd->s_sibling = (void *)&wait; |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 175 | |
| 176 | /* atomic_add_return() is a mb(), put_active() will always see |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 177 | * the updated sd->s_sibling. |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 178 | */ |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 179 | v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active); |
| 180 | |
| 181 | if (v != SD_DEACTIVATED_BIAS) |
| 182 | wait_for_completion(&wait); |
| 183 | |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 184 | sd->s_sibling = NULL; |
Tejun Heo | b6b4a43 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 185 | } |
| 186 | |
Tejun Heo | 42b37df | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 187 | static int sysfs_alloc_ino(ino_t *pino) |
Tejun Heo | 2b611bb | 2007-06-14 03:45:13 +0900 | [diff] [blame] | 188 | { |
| 189 | int ino, rc; |
| 190 | |
| 191 | retry: |
| 192 | spin_lock(&sysfs_ino_lock); |
| 193 | rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino); |
| 194 | spin_unlock(&sysfs_ino_lock); |
| 195 | |
| 196 | if (rc == -EAGAIN) { |
| 197 | if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL)) |
| 198 | goto retry; |
| 199 | rc = -ENOMEM; |
| 200 | } |
| 201 | |
| 202 | *pino = ino; |
| 203 | return rc; |
| 204 | } |
| 205 | |
| 206 | static void sysfs_free_ino(ino_t ino) |
| 207 | { |
| 208 | spin_lock(&sysfs_ino_lock); |
| 209 | ida_remove(&sysfs_ino_ida, ino); |
| 210 | spin_unlock(&sysfs_ino_lock); |
| 211 | } |
| 212 | |
Tejun Heo | fa7f912 | 2007-06-14 03:45:13 +0900 | [diff] [blame] | 213 | void release_sysfs_dirent(struct sysfs_dirent * sd) |
| 214 | { |
Tejun Heo | 13b3086 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 215 | struct sysfs_dirent *parent_sd; |
| 216 | |
| 217 | repeat: |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 218 | /* Moving/renaming is always done while holding reference. |
| 219 | * sd->s_parent won't change beneath us. |
| 220 | */ |
Tejun Heo | 13b3086 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 221 | parent_sd = sd->s_parent; |
| 222 | |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 223 | if (sysfs_type(sd) == SYSFS_KOBJ_LINK) |
Tejun Heo | 2b29ac2 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 224 | sysfs_put(sd->s_elem.symlink.target_sd); |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 225 | if (sysfs_type(sd) & SYSFS_COPY_NAME) |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 226 | kfree(sd->s_name); |
Tejun Heo | fa7f912 | 2007-06-14 03:45:13 +0900 | [diff] [blame] | 227 | kfree(sd->s_iattr); |
Tejun Heo | 2b611bb | 2007-06-14 03:45:13 +0900 | [diff] [blame] | 228 | sysfs_free_ino(sd->s_ino); |
Tejun Heo | fa7f912 | 2007-06-14 03:45:13 +0900 | [diff] [blame] | 229 | kmem_cache_free(sysfs_dir_cachep, sd); |
Tejun Heo | 13b3086 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 230 | |
| 231 | sd = parent_sd; |
| 232 | if (sd && atomic_dec_and_test(&sd->s_count)) |
| 233 | goto repeat; |
Tejun Heo | fa7f912 | 2007-06-14 03:45:13 +0900 | [diff] [blame] | 234 | } |
| 235 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | static void sysfs_d_iput(struct dentry * dentry, struct inode * inode) |
| 237 | { |
| 238 | struct sysfs_dirent * sd = dentry->d_fsdata; |
| 239 | |
| 240 | if (sd) { |
Tejun Heo | 5f99532 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 241 | /* sd->s_dentry is protected with sysfs_assoc_lock. |
| 242 | * This allows sysfs_drop_dentry() to dereference it. |
Tejun Heo | dd14cbc | 2007-06-11 14:04:01 +0900 | [diff] [blame] | 243 | */ |
Tejun Heo | 5f99532 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 244 | spin_lock(&sysfs_assoc_lock); |
Tejun Heo | dd14cbc | 2007-06-11 14:04:01 +0900 | [diff] [blame] | 245 | |
| 246 | /* The dentry might have been deleted or another |
| 247 | * lookup could have happened updating sd->s_dentry to |
| 248 | * point the new dentry. Ignore if it isn't pointing |
| 249 | * to this dentry. |
| 250 | */ |
| 251 | if (sd->s_dentry == dentry) |
| 252 | sd->s_dentry = NULL; |
Tejun Heo | 5f99532 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 253 | spin_unlock(&sysfs_assoc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | sysfs_put(sd); |
| 255 | } |
| 256 | iput(inode); |
| 257 | } |
| 258 | |
| 259 | static struct dentry_operations sysfs_dentry_ops = { |
| 260 | .d_iput = sysfs_d_iput, |
| 261 | }; |
| 262 | |
Tejun Heo | 3e51903 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 263 | struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | { |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 265 | char *dup_name = NULL; |
| 266 | struct sysfs_dirent *sd = NULL; |
| 267 | |
| 268 | if (type & SYSFS_COPY_NAME) { |
| 269 | name = dup_name = kstrdup(name, GFP_KERNEL); |
| 270 | if (!name) |
| 271 | goto err_out; |
| 272 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | |
Robert P. J. Day | c376222 | 2007-02-10 01:45:03 -0800 | [diff] [blame] | 274 | sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | if (!sd) |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 276 | goto err_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 278 | if (sysfs_alloc_ino(&sd->s_ino)) |
| 279 | goto err_out; |
Tejun Heo | 2b611bb | 2007-06-14 03:45:13 +0900 | [diff] [blame] | 280 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | atomic_set(&sd->s_count, 1); |
Tejun Heo | 8619f97 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 282 | atomic_set(&sd->s_active, 0); |
Juha Yrjölä | eea3f89 | 2006-08-03 19:06:25 +0300 | [diff] [blame] | 283 | atomic_set(&sd->s_event, 1); |
Tejun Heo | a26cd72 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 284 | |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 285 | sd->s_name = name; |
Tejun Heo | a26cd72 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 286 | sd->s_mode = mode; |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 287 | sd->s_flags = type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | |
| 289 | return sd; |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 290 | |
| 291 | err_out: |
| 292 | kfree(dup_name); |
| 293 | kmem_cache_free(sysfs_dir_cachep, sd); |
| 294 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | } |
| 296 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 297 | /** |
| 298 | * sysfs_attach_dentry - associate sysfs_dirent with dentry |
| 299 | * @sd: target sysfs_dirent |
| 300 | * @dentry: dentry to associate |
| 301 | * |
| 302 | * Associate @sd with @dentry. This is protected by |
| 303 | * sysfs_assoc_lock to avoid race with sysfs_d_iput(). |
| 304 | * |
| 305 | * LOCKING: |
| 306 | * mutex_lock(sysfs_mutex) |
| 307 | */ |
Tejun Heo | 198a2a8 | 2007-06-14 03:45:16 +0900 | [diff] [blame] | 308 | static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry) |
| 309 | { |
| 310 | dentry->d_op = &sysfs_dentry_ops; |
| 311 | dentry->d_fsdata = sysfs_get(sd); |
| 312 | |
| 313 | /* protect sd->s_dentry against sysfs_d_iput */ |
Tejun Heo | 5f99532 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 314 | spin_lock(&sysfs_assoc_lock); |
Tejun Heo | 198a2a8 | 2007-06-14 03:45:16 +0900 | [diff] [blame] | 315 | sd->s_dentry = dentry; |
Tejun Heo | 5f99532 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 316 | spin_unlock(&sysfs_assoc_lock); |
Tejun Heo | 198a2a8 | 2007-06-14 03:45:16 +0900 | [diff] [blame] | 317 | |
| 318 | d_rehash(dentry); |
| 319 | } |
| 320 | |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 321 | static int sysfs_ilookup_test(struct inode *inode, void *arg) |
| 322 | { |
| 323 | struct sysfs_dirent *sd = arg; |
| 324 | return inode->i_ino == sd->s_ino; |
| 325 | } |
| 326 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 327 | /** |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 328 | * sysfs_addrm_start - prepare for sysfs_dirent add/remove |
| 329 | * @acxt: pointer to sysfs_addrm_cxt to be used |
| 330 | * @parent_sd: parent sysfs_dirent |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 331 | * |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 332 | * This function is called when the caller is about to add or |
| 333 | * remove sysfs_dirent under @parent_sd. This function acquires |
| 334 | * sysfs_mutex, grabs inode for @parent_sd if available and lock |
| 335 | * i_mutex of it. @acxt is used to keep and pass context to |
| 336 | * other addrm functions. |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 337 | * |
| 338 | * LOCKING: |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 339 | * Kernel thread context (may sleep). sysfs_mutex is locked on |
| 340 | * return. i_mutex of parent inode is locked on return if |
| 341 | * available. |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 342 | */ |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 343 | void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, |
| 344 | struct sysfs_dirent *parent_sd) |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 345 | { |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 346 | struct inode *inode; |
Tejun Heo | a26cd72 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 347 | |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 348 | memset(acxt, 0, sizeof(*acxt)); |
| 349 | acxt->parent_sd = parent_sd; |
| 350 | |
| 351 | /* Lookup parent inode. inode initialization and I_NEW |
| 352 | * clearing are protected by sysfs_mutex. By grabbing it and |
| 353 | * looking up with _nowait variant, inode state can be |
| 354 | * determined reliably. |
| 355 | */ |
| 356 | mutex_lock(&sysfs_mutex); |
| 357 | |
| 358 | inode = ilookup5_nowait(sysfs_sb, parent_sd->s_ino, sysfs_ilookup_test, |
| 359 | parent_sd); |
| 360 | |
| 361 | if (inode && !(inode->i_state & I_NEW)) { |
| 362 | /* parent inode available */ |
| 363 | acxt->parent_inode = inode; |
| 364 | |
| 365 | /* sysfs_mutex is below i_mutex in lock hierarchy. |
| 366 | * First, trylock i_mutex. If fails, unlock |
| 367 | * sysfs_mutex and lock them in order. |
| 368 | */ |
| 369 | if (!mutex_trylock(&inode->i_mutex)) { |
| 370 | mutex_unlock(&sysfs_mutex); |
| 371 | mutex_lock(&inode->i_mutex); |
| 372 | mutex_lock(&sysfs_mutex); |
| 373 | } |
| 374 | } else |
| 375 | iput(inode); |
| 376 | } |
| 377 | |
| 378 | /** |
| 379 | * sysfs_add_one - add sysfs_dirent to parent |
| 380 | * @acxt: addrm context to use |
| 381 | * @sd: sysfs_dirent to be added |
| 382 | * |
| 383 | * Get @acxt->parent_sd and set sd->s_parent to it and increment |
| 384 | * nlink of parent inode if @sd is a directory. @sd is NOT |
| 385 | * linked into the children list of the parent. The caller |
| 386 | * should invoke sysfs_link_sibling() after this function |
| 387 | * completes if @sd needs to be on the children list. |
| 388 | * |
| 389 | * This function should be called between calls to |
| 390 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be |
| 391 | * passed the same @acxt as passed to sysfs_addrm_start(). |
| 392 | * |
| 393 | * LOCKING: |
| 394 | * Determined by sysfs_addrm_start(). |
| 395 | */ |
| 396 | void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) |
| 397 | { |
| 398 | sd->s_parent = sysfs_get(acxt->parent_sd); |
| 399 | |
| 400 | if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) |
| 401 | inc_nlink(acxt->parent_inode); |
| 402 | |
| 403 | acxt->cnt++; |
| 404 | } |
| 405 | |
| 406 | /** |
| 407 | * sysfs_remove_one - remove sysfs_dirent from parent |
| 408 | * @acxt: addrm context to use |
| 409 | * @sd: sysfs_dirent to be added |
| 410 | * |
| 411 | * Mark @sd removed and drop nlink of parent inode if @sd is a |
| 412 | * directory. @sd is NOT unlinked from the children list of the |
| 413 | * parent. The caller is repsonsible for removing @sd from the |
| 414 | * children list before calling this function. |
| 415 | * |
| 416 | * This function should be called between calls to |
| 417 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be |
| 418 | * passed the same @acxt as passed to sysfs_addrm_start(). |
| 419 | * |
| 420 | * LOCKING: |
| 421 | * Determined by sysfs_addrm_start(). |
| 422 | */ |
| 423 | void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) |
| 424 | { |
| 425 | BUG_ON(sd->s_sibling || (sd->s_flags & SYSFS_FLAG_REMOVED)); |
| 426 | |
| 427 | sd->s_flags |= SYSFS_FLAG_REMOVED; |
| 428 | sd->s_sibling = acxt->removed; |
| 429 | acxt->removed = sd; |
| 430 | |
| 431 | if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) |
| 432 | drop_nlink(acxt->parent_inode); |
| 433 | |
| 434 | acxt->cnt++; |
| 435 | } |
| 436 | |
| 437 | /** |
| 438 | * sysfs_addrm_finish - finish up sysfs_dirent add/remove |
| 439 | * @acxt: addrm context to finish up |
| 440 | * |
| 441 | * Finish up sysfs_dirent add/remove. Resources acquired by |
| 442 | * sysfs_addrm_start() are released and removed sysfs_dirents are |
| 443 | * cleaned up. Timestamps on the parent inode are updated. |
| 444 | * |
| 445 | * LOCKING: |
| 446 | * All mutexes acquired by sysfs_addrm_start() are released. |
| 447 | * |
| 448 | * RETURNS: |
| 449 | * Number of added/removed sysfs_dirents since sysfs_addrm_start(). |
| 450 | */ |
| 451 | int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) |
| 452 | { |
| 453 | /* release resources acquired by sysfs_addrm_start() */ |
| 454 | mutex_unlock(&sysfs_mutex); |
| 455 | if (acxt->parent_inode) { |
| 456 | struct inode *inode = acxt->parent_inode; |
| 457 | |
| 458 | /* if added/removed, update timestamps on the parent */ |
| 459 | if (acxt->cnt) |
| 460 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
| 461 | |
| 462 | mutex_unlock(&inode->i_mutex); |
| 463 | iput(inode); |
Tejun Heo | 13b3086 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 464 | } |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 465 | |
| 466 | /* kill removed sysfs_dirents */ |
| 467 | while (acxt->removed) { |
| 468 | struct sysfs_dirent *sd = acxt->removed; |
| 469 | |
| 470 | acxt->removed = sd->s_sibling; |
| 471 | sd->s_sibling = NULL; |
| 472 | |
| 473 | sysfs_drop_dentry(sd); |
| 474 | sysfs_deactivate(sd); |
| 475 | sysfs_put(sd); |
| 476 | } |
| 477 | |
| 478 | return acxt->cnt; |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 479 | } |
| 480 | |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 481 | /** |
| 482 | * sysfs_find_dirent - find sysfs_dirent with the given name |
| 483 | * @parent_sd: sysfs_dirent to search under |
| 484 | * @name: name to look for |
Maneesh Soni | c516865 | 2006-03-09 19:40:14 +0530 | [diff] [blame] | 485 | * |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 486 | * Look for sysfs_dirent with name @name under @parent_sd. |
Maneesh Soni | c516865 | 2006-03-09 19:40:14 +0530 | [diff] [blame] | 487 | * |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 488 | * LOCKING: |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 489 | * mutex_lock(sysfs_mutex) |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 490 | * |
| 491 | * RETURNS: |
| 492 | * Pointer to sysfs_dirent if found, NULL if not. |
Maneesh Soni | c516865 | 2006-03-09 19:40:14 +0530 | [diff] [blame] | 493 | */ |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 494 | struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, |
| 495 | const unsigned char *name) |
Maneesh Soni | c516865 | 2006-03-09 19:40:14 +0530 | [diff] [blame] | 496 | { |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 497 | struct sysfs_dirent *sd; |
Maneesh Soni | c516865 | 2006-03-09 19:40:14 +0530 | [diff] [blame] | 498 | |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 499 | for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) |
| 500 | if (sysfs_type(sd) && !strcmp(sd->s_name, name)) |
| 501 | return sd; |
| 502 | return NULL; |
| 503 | } |
Maneesh Soni | c516865 | 2006-03-09 19:40:14 +0530 | [diff] [blame] | 504 | |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 505 | /** |
| 506 | * sysfs_get_dirent - find and get sysfs_dirent with the given name |
| 507 | * @parent_sd: sysfs_dirent to search under |
| 508 | * @name: name to look for |
| 509 | * |
| 510 | * Look for sysfs_dirent with name @name under @parent_sd and get |
| 511 | * it if found. |
| 512 | * |
| 513 | * LOCKING: |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 514 | * Kernel thread context (may sleep). Grabs sysfs_mutex. |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 515 | * |
| 516 | * RETURNS: |
| 517 | * Pointer to sysfs_dirent if found, NULL if not. |
| 518 | */ |
| 519 | struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, |
| 520 | const unsigned char *name) |
| 521 | { |
| 522 | struct sysfs_dirent *sd; |
| 523 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 524 | mutex_lock(&sysfs_mutex); |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 525 | sd = sysfs_find_dirent(parent_sd, name); |
| 526 | sysfs_get(sd); |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 527 | mutex_unlock(&sysfs_mutex); |
Tejun Heo | f0b0af4 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 528 | |
| 529 | return sd; |
Maneesh Soni | c516865 | 2006-03-09 19:40:14 +0530 | [diff] [blame] | 530 | } |
| 531 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 532 | static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, |
| 533 | const char *name, struct sysfs_dirent **p_sd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | { |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 535 | struct dentry *parent = parent_sd->s_dentry; |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 536 | struct sysfs_addrm_cxt acxt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | int error; |
| 538 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 539 | struct dentry *dentry; |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 540 | struct inode *inode; |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 541 | struct sysfs_dirent *sd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 543 | sysfs_addrm_start(&acxt, parent_sd); |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 544 | |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 545 | /* allocate */ |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 546 | dentry = lookup_one_len(name, parent, strlen(name)); |
| 547 | if (IS_ERR(dentry)) { |
| 548 | error = PTR_ERR(dentry); |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 549 | goto out_finish; |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 550 | } |
| 551 | |
| 552 | error = -EEXIST; |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 553 | if (dentry->d_inode) |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 554 | goto out_dput; |
| 555 | |
Tejun Heo | a26cd72 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 556 | error = -ENOMEM; |
Tejun Heo | 3e51903 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 557 | sd = sysfs_new_dirent(name, mode, SYSFS_DIR); |
Tejun Heo | a26cd72 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 558 | if (!sd) |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 559 | goto out_drop; |
Tejun Heo | 3e51903 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 560 | sd->s_elem.dir.kobj = kobj; |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 561 | |
Tejun Heo | 8312a8d | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 562 | inode = sysfs_get_inode(sd); |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 563 | if (!inode) |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 564 | goto out_sput; |
| 565 | |
Tejun Heo | 8312a8d | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 566 | if (inode->i_state & I_NEW) { |
| 567 | inode->i_op = &sysfs_dir_inode_operations; |
| 568 | inode->i_fop = &sysfs_dir_operations; |
| 569 | /* directory inodes start off with i_nlink == 2 (for ".") */ |
| 570 | inc_nlink(inode); |
| 571 | } |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 572 | |
| 573 | /* link in */ |
| 574 | error = -EEXIST; |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 575 | if (sysfs_find_dirent(parent_sd, name)) |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 576 | goto out_iput; |
| 577 | |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 578 | sysfs_add_one(&acxt, sd); |
| 579 | sysfs_link_sibling(sd); |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 580 | sysfs_instantiate(dentry, inode); |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 581 | sysfs_attach_dentry(sd, dentry); |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 582 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 583 | *p_sd = sd; |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 584 | error = 0; |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 585 | goto out_finish; /* pin directory dentry in core */ |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 586 | |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 587 | out_iput: |
| 588 | iput(inode); |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 589 | out_sput: |
Tejun Heo | dfeb9fb | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 590 | sysfs_put(sd); |
| 591 | out_drop: |
| 592 | d_drop(dentry); |
| 593 | out_dput: |
| 594 | dput(dentry); |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 595 | out_finish: |
| 596 | sysfs_addrm_finish(&acxt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | return error; |
| 598 | } |
| 599 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 600 | int sysfs_create_subdir(struct kobject *kobj, const char *name, |
| 601 | struct sysfs_dirent **p_sd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | { |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 603 | return create_dir(kobj, kobj->sd, name, p_sd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 604 | } |
| 605 | |
| 606 | /** |
| 607 | * sysfs_create_dir - create a directory for an object. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | * @kobj: object we're creating directory for. |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 609 | * @shadow_parent: parent object. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 610 | */ |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 611 | int sysfs_create_dir(struct kobject *kobj, |
| 612 | struct sysfs_dirent *shadow_parent_sd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | { |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 614 | struct sysfs_dirent *parent_sd, *sd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | int error = 0; |
| 616 | |
| 617 | BUG_ON(!kobj); |
| 618 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 619 | if (shadow_parent_sd) |
| 620 | parent_sd = shadow_parent_sd; |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 621 | else if (kobj->parent) |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 622 | parent_sd = kobj->parent->sd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | else if (sysfs_mount && sysfs_mount->mnt_sb) |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 624 | parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | else |
| 626 | return -EFAULT; |
| 627 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 628 | error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | if (!error) |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 630 | kobj->sd = sd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | return error; |
| 632 | } |
| 633 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, |
| 635 | struct nameidata *nd) |
| 636 | { |
| 637 | struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata; |
| 638 | struct sysfs_dirent * sd; |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 639 | struct bin_attribute *bin_attr; |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 640 | struct inode *inode; |
| 641 | int found = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 643 | for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) { |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 644 | if ((sysfs_type(sd) & SYSFS_NOT_PINNED) && |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 645 | !strcmp(sd->s_name, dentry->d_name.name)) { |
| 646 | found = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | break; |
| 648 | } |
| 649 | } |
| 650 | |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 651 | /* no such entry */ |
| 652 | if (!found) |
| 653 | return NULL; |
| 654 | |
| 655 | /* attach dentry and inode */ |
Tejun Heo | 8312a8d | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 656 | inode = sysfs_get_inode(sd); |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 657 | if (!inode) |
| 658 | return ERR_PTR(-ENOMEM); |
| 659 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 660 | mutex_lock(&sysfs_mutex); |
| 661 | |
Tejun Heo | 8312a8d | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 662 | if (inode->i_state & I_NEW) { |
| 663 | /* initialize inode according to type */ |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 664 | switch (sysfs_type(sd)) { |
| 665 | case SYSFS_KOBJ_ATTR: |
Tejun Heo | 8312a8d | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 666 | inode->i_size = PAGE_SIZE; |
| 667 | inode->i_fop = &sysfs_file_operations; |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 668 | break; |
| 669 | case SYSFS_KOBJ_BIN_ATTR: |
| 670 | bin_attr = sd->s_elem.bin_attr.bin_attr; |
Tejun Heo | 8312a8d | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 671 | inode->i_size = bin_attr->size; |
| 672 | inode->i_fop = &bin_fops; |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 673 | break; |
| 674 | case SYSFS_KOBJ_LINK: |
Tejun Heo | 8312a8d | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 675 | inode->i_op = &sysfs_symlink_inode_operations; |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 676 | break; |
| 677 | default: |
| 678 | BUG(); |
| 679 | } |
Tejun Heo | 8312a8d | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 680 | } |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 681 | |
| 682 | sysfs_instantiate(dentry, inode); |
| 683 | sysfs_attach_dentry(sd, dentry); |
| 684 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 685 | mutex_unlock(&sysfs_mutex); |
| 686 | |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 687 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 688 | } |
| 689 | |
Arjan van de Ven | c5ef1c4 | 2007-02-12 00:55:40 -0800 | [diff] [blame] | 690 | const struct inode_operations sysfs_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | .lookup = sysfs_lookup, |
Maneesh Soni | 988d186 | 2005-05-31 10:39:14 +0530 | [diff] [blame] | 692 | .setattr = sysfs_setattr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | }; |
| 694 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 695 | static void remove_dir(struct sysfs_dirent *sd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | { |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 697 | struct sysfs_addrm_cxt acxt; |
| 698 | |
| 699 | sysfs_addrm_start(&acxt, sd->s_parent); |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 700 | sysfs_unlink_sibling(sd); |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 701 | sysfs_remove_one(&acxt, sd); |
| 702 | sysfs_addrm_finish(&acxt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | } |
| 704 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 705 | void sysfs_remove_subdir(struct sysfs_dirent *sd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | { |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 707 | remove_dir(sd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | } |
| 709 | |
| 710 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 711 | static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | { |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 713 | struct sysfs_addrm_cxt acxt; |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 714 | struct sysfs_dirent **pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 715 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 716 | if (!dir_sd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | return; |
| 718 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 719 | pr_debug("sysfs %s: removing dir\n", dir_sd->s_name); |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 720 | sysfs_addrm_start(&acxt, dir_sd); |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 721 | pos = &dir_sd->s_children; |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 722 | while (*pos) { |
| 723 | struct sysfs_dirent *sd = *pos; |
| 724 | |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 725 | if (sysfs_type(sd) && (sysfs_type(sd) & SYSFS_NOT_PINNED)) { |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 726 | *pos = sd->s_sibling; |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 727 | sd->s_sibling = NULL; |
| 728 | sysfs_remove_one(&acxt, sd); |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 729 | } else |
| 730 | pos = &(*pos)->s_sibling; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | } |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 732 | sysfs_addrm_finish(&acxt); |
Tejun Heo | 0ab6608 | 2007-06-14 03:45:16 +0900 | [diff] [blame] | 733 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 734 | remove_dir(dir_sd); |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 735 | } |
| 736 | |
| 737 | /** |
| 738 | * sysfs_remove_dir - remove an object's directory. |
| 739 | * @kobj: object. |
| 740 | * |
| 741 | * The only thing special about this is that we remove any files in |
| 742 | * the directory before we remove the directory, and we've inlined |
| 743 | * what used to be sysfs_rmdir() below, instead of calling separately. |
| 744 | */ |
| 745 | |
| 746 | void sysfs_remove_dir(struct kobject * kobj) |
| 747 | { |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 748 | struct sysfs_dirent *sd = kobj->sd; |
Tejun Heo | aecdced | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 749 | |
Tejun Heo | 5f99532 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 750 | spin_lock(&sysfs_assoc_lock); |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 751 | kobj->sd = NULL; |
Tejun Heo | 5f99532 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 752 | spin_unlock(&sysfs_assoc_lock); |
Tejun Heo | aecdced | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 753 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 754 | __sysfs_remove_dir(sd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | } |
| 756 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 757 | int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd, |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 758 | const char *new_name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | { |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 760 | struct sysfs_dirent *sd = kobj->sd; |
| 761 | struct dentry *new_parent = new_parent_sd->s_dentry; |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 762 | struct dentry *new_dentry; |
| 763 | char *dup_name; |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 764 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 766 | if (!new_parent_sd) |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 767 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 769 | mutex_lock(&new_parent->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 771 | new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name)); |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 772 | if (IS_ERR(new_dentry)) { |
| 773 | error = PTR_ERR(new_dentry); |
| 774 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | } |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 776 | |
| 777 | /* By allowing two different directories with the same |
| 778 | * d_parent we allow this routine to move between different |
| 779 | * shadows of the same directory |
| 780 | */ |
| 781 | error = -EINVAL; |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 782 | if (sd->s_parent->s_dentry->d_inode != new_parent->d_inode || |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 783 | new_dentry->d_parent->d_inode != new_parent->d_inode || |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 784 | new_dentry == sd->s_dentry) |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 785 | goto out_dput; |
| 786 | |
| 787 | error = -EEXIST; |
| 788 | if (new_dentry->d_inode) |
| 789 | goto out_dput; |
| 790 | |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 791 | /* rename kobject and sysfs_dirent */ |
| 792 | error = -ENOMEM; |
| 793 | new_name = dup_name = kstrdup(new_name, GFP_KERNEL); |
| 794 | if (!new_name) |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 795 | goto out_drop; |
| 796 | |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 797 | error = kobject_set_name(kobj, "%s", new_name); |
| 798 | if (error) |
| 799 | goto out_free; |
| 800 | |
| 801 | kfree(sd->s_name); |
| 802 | sd->s_name = new_name; |
| 803 | |
| 804 | /* move under the new parent */ |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 805 | d_add(new_dentry, NULL); |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 806 | d_move(sd->s_dentry, new_dentry); |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 807 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 808 | mutex_lock(&sysfs_mutex); |
| 809 | |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 810 | sysfs_unlink_sibling(sd); |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 811 | sysfs_get(new_parent_sd); |
Tejun Heo | 7f7cfff | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 812 | sysfs_put(sd->s_parent); |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 813 | sd->s_parent = new_parent_sd; |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 814 | sysfs_link_sibling(sd); |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 815 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 816 | mutex_unlock(&sysfs_mutex); |
| 817 | |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 818 | error = 0; |
| 819 | goto out_unlock; |
| 820 | |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 821 | out_free: |
| 822 | kfree(dup_name); |
Tejun Heo | 996b737 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 823 | out_drop: |
| 824 | d_drop(new_dentry); |
| 825 | out_dput: |
| 826 | dput(new_dentry); |
| 827 | out_unlock: |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 828 | mutex_unlock(&new_parent->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | return error; |
| 830 | } |
| 831 | |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 832 | int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent) |
| 833 | { |
| 834 | struct dentry *old_parent_dentry, *new_parent_dentry, *new_dentry; |
| 835 | struct sysfs_dirent *new_parent_sd, *sd; |
| 836 | int error; |
| 837 | |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 838 | old_parent_dentry = kobj->parent ? |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 839 | kobj->parent->sd->s_dentry : sysfs_mount->mnt_sb->s_root; |
Cornelia Huck | c744aeae | 2007-01-08 20:16:44 +0100 | [diff] [blame] | 840 | new_parent_dentry = new_parent ? |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 841 | new_parent->sd->s_dentry : sysfs_mount->mnt_sb->s_root; |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 842 | |
Mark Lord | 0de1517 | 2007-03-06 01:42:03 -0800 | [diff] [blame] | 843 | if (old_parent_dentry->d_inode == new_parent_dentry->d_inode) |
| 844 | return 0; /* nothing to move */ |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 845 | again: |
| 846 | mutex_lock(&old_parent_dentry->d_inode->i_mutex); |
| 847 | if (!mutex_trylock(&new_parent_dentry->d_inode->i_mutex)) { |
| 848 | mutex_unlock(&old_parent_dentry->d_inode->i_mutex); |
| 849 | goto again; |
| 850 | } |
| 851 | |
| 852 | new_parent_sd = new_parent_dentry->d_fsdata; |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 853 | sd = kobj->sd; |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 854 | |
| 855 | new_dentry = lookup_one_len(kobj->name, new_parent_dentry, |
| 856 | strlen(kobj->name)); |
| 857 | if (IS_ERR(new_dentry)) { |
| 858 | error = PTR_ERR(new_dentry); |
| 859 | goto out; |
| 860 | } else |
| 861 | error = 0; |
| 862 | d_add(new_dentry, NULL); |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 863 | d_move(sd->s_dentry, new_dentry); |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 864 | dput(new_dentry); |
| 865 | |
| 866 | /* Remove from old parent's list and insert into new parent's list. */ |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 867 | mutex_lock(&sysfs_mutex); |
| 868 | |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 869 | sysfs_unlink_sibling(sd); |
Tejun Heo | 7f7cfff | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 870 | sysfs_get(new_parent_sd); |
| 871 | sysfs_put(sd->s_parent); |
| 872 | sd->s_parent = new_parent_sd; |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 873 | sysfs_link_sibling(sd); |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 874 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 875 | mutex_unlock(&sysfs_mutex); |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 876 | out: |
| 877 | mutex_unlock(&new_parent_dentry->d_inode->i_mutex); |
| 878 | mutex_unlock(&old_parent_dentry->d_inode->i_mutex); |
| 879 | |
| 880 | return error; |
| 881 | } |
| 882 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 883 | static int sysfs_dir_open(struct inode *inode, struct file *file) |
| 884 | { |
Josef "Jeff" Sipek | f427f5d | 2006-12-08 02:36:36 -0800 | [diff] [blame] | 885 | struct dentry * dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 886 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
Tejun Heo | a26cd72 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 887 | struct sysfs_dirent * sd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | |
Tejun Heo | 3e51903 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 889 | sd = sysfs_new_dirent("_DIR_", 0, 0); |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 890 | if (sd) { |
| 891 | mutex_lock(&sysfs_mutex); |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 892 | sd->s_parent = sysfs_get(parent_sd); |
| 893 | sysfs_link_sibling(sd); |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 894 | mutex_unlock(&sysfs_mutex); |
| 895 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 896 | |
Tejun Heo | a26cd72 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 897 | file->private_data = sd; |
| 898 | return sd ? 0 : -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | } |
| 900 | |
| 901 | static int sysfs_dir_close(struct inode *inode, struct file *file) |
| 902 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | struct sysfs_dirent * cursor = file->private_data; |
| 904 | |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 905 | mutex_lock(&sysfs_mutex); |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 906 | sysfs_unlink_sibling(cursor); |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 907 | mutex_unlock(&sysfs_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 908 | |
| 909 | release_sysfs_dirent(cursor); |
| 910 | |
| 911 | return 0; |
| 912 | } |
| 913 | |
| 914 | /* Relationship between s_mode and the DT_xxx types */ |
| 915 | static inline unsigned char dt_type(struct sysfs_dirent *sd) |
| 916 | { |
| 917 | return (sd->s_mode >> 12) & 15; |
| 918 | } |
| 919 | |
| 920 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) |
| 921 | { |
Josef "Jeff" Sipek | f427f5d | 2006-12-08 02:36:36 -0800 | [diff] [blame] | 922 | struct dentry *dentry = filp->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
| 924 | struct sysfs_dirent *cursor = filp->private_data; |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 925 | struct sysfs_dirent **pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 926 | ino_t ino; |
| 927 | int i = filp->f_pos; |
| 928 | |
| 929 | switch (i) { |
| 930 | case 0: |
Eric Sandeen | dc35125 | 2007-06-11 14:02:45 +0900 | [diff] [blame] | 931 | ino = parent_sd->s_ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 932 | if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) |
| 933 | break; |
| 934 | filp->f_pos++; |
| 935 | i++; |
| 936 | /* fallthrough */ |
| 937 | case 1: |
Tejun Heo | 13b3086 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 938 | if (parent_sd->s_parent) |
| 939 | ino = parent_sd->s_parent->s_ino; |
| 940 | else |
| 941 | ino = parent_sd->s_ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 942 | if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) |
| 943 | break; |
| 944 | filp->f_pos++; |
| 945 | i++; |
| 946 | /* fallthrough */ |
| 947 | default: |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 948 | mutex_lock(&sysfs_mutex); |
| 949 | |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 950 | pos = &parent_sd->s_children; |
| 951 | while (*pos != cursor) |
| 952 | pos = &(*pos)->s_sibling; |
Akinobu Mita | 1bfba4e | 2006-06-26 00:24:40 -0700 | [diff] [blame] | 953 | |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 954 | /* unlink cursor */ |
| 955 | *pos = cursor->s_sibling; |
| 956 | |
| 957 | if (filp->f_pos == 2) |
| 958 | pos = &parent_sd->s_children; |
| 959 | |
| 960 | for ( ; *pos; pos = &(*pos)->s_sibling) { |
| 961 | struct sysfs_dirent *next = *pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 962 | const char * name; |
| 963 | int len; |
| 964 | |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 965 | if (!sysfs_type(next)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | continue; |
| 967 | |
Tejun Heo | 0c096b5 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 968 | name = next->s_name; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 969 | len = strlen(name); |
Eric Sandeen | dc35125 | 2007-06-11 14:02:45 +0900 | [diff] [blame] | 970 | ino = next->s_ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | |
| 972 | if (filldir(dirent, name, len, filp->f_pos, ino, |
| 973 | dt_type(next)) < 0) |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 974 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 975 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | filp->f_pos++; |
| 977 | } |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 978 | |
| 979 | /* put cursor back in */ |
| 980 | cursor->s_sibling = *pos; |
| 981 | *pos = cursor; |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 982 | |
| 983 | mutex_unlock(&sysfs_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | } |
| 985 | return 0; |
| 986 | } |
| 987 | |
| 988 | static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin) |
| 989 | { |
Josef "Jeff" Sipek | f427f5d | 2006-12-08 02:36:36 -0800 | [diff] [blame] | 990 | struct dentry * dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | switch (origin) { |
| 993 | case 1: |
| 994 | offset += file->f_pos; |
| 995 | case 0: |
| 996 | if (offset >= 0) |
| 997 | break; |
| 998 | default: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 999 | return -EINVAL; |
| 1000 | } |
| 1001 | if (offset != file->f_pos) { |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 1002 | mutex_lock(&sysfs_mutex); |
| 1003 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | file->f_pos = offset; |
| 1005 | if (file->f_pos >= 2) { |
| 1006 | struct sysfs_dirent *sd = dentry->d_fsdata; |
| 1007 | struct sysfs_dirent *cursor = file->private_data; |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 1008 | struct sysfs_dirent **pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1009 | loff_t n = file->f_pos - 2; |
| 1010 | |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 1011 | sysfs_unlink_sibling(cursor); |
| 1012 | |
| 1013 | pos = &sd->s_children; |
| 1014 | while (n && *pos) { |
| 1015 | struct sysfs_dirent *next = *pos; |
Tejun Heo | b402d72 | 2007-06-14 04:27:21 +0900 | [diff] [blame] | 1016 | if (sysfs_type(next)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1017 | n--; |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 1018 | pos = &(*pos)->s_sibling; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1019 | } |
Tejun Heo | 0c73f18 | 2007-06-14 03:45:18 +0900 | [diff] [blame] | 1020 | |
| 1021 | cursor->s_sibling = *pos; |
| 1022 | *pos = cursor; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1023 | } |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 1024 | |
| 1025 | mutex_unlock(&sysfs_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1026 | } |
Tejun Heo | 3007e99 | 2007-06-14 04:27:23 +0900 | [diff] [blame] | 1027 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1028 | return offset; |
| 1029 | } |
| 1030 | |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1031 | |
| 1032 | /** |
| 1033 | * sysfs_make_shadowed_dir - Setup so a directory can be shadowed |
| 1034 | * @kobj: object we're creating shadow of. |
| 1035 | */ |
| 1036 | |
| 1037 | int sysfs_make_shadowed_dir(struct kobject *kobj, |
| 1038 | void * (*follow_link)(struct dentry *, struct nameidata *)) |
| 1039 | { |
| 1040 | struct inode *inode; |
| 1041 | struct inode_operations *i_op; |
| 1042 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 1043 | inode = kobj->sd->s_dentry->d_inode; |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1044 | if (inode->i_op != &sysfs_dir_inode_operations) |
| 1045 | return -EINVAL; |
| 1046 | |
| 1047 | i_op = kmalloc(sizeof(*i_op), GFP_KERNEL); |
| 1048 | if (!i_op) |
| 1049 | return -ENOMEM; |
| 1050 | |
| 1051 | memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op)); |
| 1052 | i_op->follow_link = follow_link; |
| 1053 | |
| 1054 | /* Locking of inode->i_op? |
| 1055 | * Since setting i_op is a single word write and they |
| 1056 | * are atomic we should be ok here. |
| 1057 | */ |
| 1058 | inode->i_op = i_op; |
| 1059 | return 0; |
| 1060 | } |
| 1061 | |
| 1062 | /** |
| 1063 | * sysfs_create_shadow_dir - create a shadow directory for an object. |
| 1064 | * @kobj: object we're creating directory for. |
| 1065 | * |
| 1066 | * sysfs_make_shadowed_dir must already have been called on this |
| 1067 | * directory. |
| 1068 | */ |
| 1069 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 1070 | struct sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj) |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1071 | { |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 1072 | struct dentry *dir = kobj->sd->s_dentry; |
Tejun Heo | 13b3086 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 1073 | struct inode *inode = dir->d_inode; |
| 1074 | struct dentry *parent = dir->d_parent; |
| 1075 | struct sysfs_dirent *parent_sd = parent->d_fsdata; |
| 1076 | struct dentry *shadow; |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1077 | struct sysfs_dirent *sd; |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 1078 | struct sysfs_addrm_cxt acxt; |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1079 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 1080 | sd = ERR_PTR(-EINVAL); |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1081 | if (!sysfs_is_shadowed_inode(inode)) |
| 1082 | goto out; |
| 1083 | |
| 1084 | shadow = d_alloc(parent, &dir->d_name); |
| 1085 | if (!shadow) |
| 1086 | goto nomem; |
| 1087 | |
Tejun Heo | 3e51903 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 1088 | sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR); |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1089 | if (!sd) |
| 1090 | goto nomem; |
Tejun Heo | 3e51903 | 2007-06-14 03:45:15 +0900 | [diff] [blame] | 1091 | sd->s_elem.dir.kobj = kobj; |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1092 | |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 1093 | sysfs_addrm_start(&acxt, parent_sd); |
| 1094 | |
| 1095 | /* add but don't link into children list */ |
| 1096 | sysfs_add_one(&acxt, sd); |
| 1097 | |
| 1098 | /* attach and instantiate dentry */ |
| 1099 | sysfs_attach_dentry(sd, shadow); |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1100 | d_instantiate(shadow, igrab(inode)); |
Tejun Heo | fb6896d | 2007-06-14 04:27:24 +0900 | [diff] [blame^] | 1101 | inc_nlink(inode); /* tj: synchronization? */ |
| 1102 | |
| 1103 | sysfs_addrm_finish(&acxt); |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1104 | |
| 1105 | dget(shadow); /* Extra count - pin the dentry in core */ |
| 1106 | |
| 1107 | out: |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 1108 | return sd; |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1109 | nomem: |
| 1110 | dput(shadow); |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 1111 | sd = ERR_PTR(-ENOMEM); |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1112 | goto out; |
| 1113 | } |
| 1114 | |
| 1115 | /** |
| 1116 | * sysfs_remove_shadow_dir - remove an object's directory. |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 1117 | * @shadow_sd: sysfs_dirent of shadow directory |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1118 | * |
| 1119 | * The only thing special about this is that we remove any files in |
| 1120 | * the directory before we remove the directory, and we've inlined |
| 1121 | * what used to be sysfs_rmdir() below, instead of calling separately. |
| 1122 | */ |
| 1123 | |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 1124 | void sysfs_remove_shadow_dir(struct sysfs_dirent *shadow_sd) |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1125 | { |
Tejun Heo | 608e266 | 2007-06-14 04:27:22 +0900 | [diff] [blame] | 1126 | __sysfs_remove_dir(shadow_sd); |
Eric W. Biederman | b592fcf | 2007-01-24 12:35:52 -0700 | [diff] [blame] | 1127 | } |
| 1128 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 1129 | const struct file_operations sysfs_dir_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | .open = sysfs_dir_open, |
| 1131 | .release = sysfs_dir_close, |
| 1132 | .llseek = sysfs_dir_lseek, |
| 1133 | .read = generic_read_dir, |
| 1134 | .readdir = sysfs_readdir, |
| 1135 | }; |