diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2009-09-08 20:55:21 -0400 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2009-09-08 20:55:21 -0400 |
| commit | bbb20089a3275a19e475dbc21320c3742e3ca423 (patch) | |
| tree | 216fdc1cbef450ca688135c5b8969169482d9a48 /include/linux/fsnotify_backend.h | |
| parent | 3e48e656903e9fd8bc805c6a2c4264d7808d315b (diff) | |
| parent | 657a77fa7284d8ae28dfa48f1dc5d919bf5b2843 (diff) | |
Merge branch 'dmaengine' into async-tx-next
Conflicts:
crypto/async_tx/async_xor.c
drivers/dma/ioat/dma_v2.h
drivers/dma/ioat/pci.c
drivers/md/raid5.c
Diffstat (limited to 'include/linux/fsnotify_backend.h')
| -rw-r--r-- | include/linux/fsnotify_backend.h | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h new file mode 100644 index 000000000000..44848aa830dc --- /dev/null +++ b/include/linux/fsnotify_backend.h | |||
| @@ -0,0 +1,387 @@ | |||
| 1 | /* | ||
| 2 | * Filesystem access notification for Linux | ||
| 3 | * | ||
| 4 | * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com> | ||
| 5 | */ | ||
| 6 | |||
| 7 | #ifndef __LINUX_FSNOTIFY_BACKEND_H | ||
| 8 | #define __LINUX_FSNOTIFY_BACKEND_H | ||
| 9 | |||
| 10 | #ifdef __KERNEL__ | ||
| 11 | |||
| 12 | #include <linux/idr.h> /* inotify uses this */ | ||
| 13 | #include <linux/fs.h> /* struct inode */ | ||
| 14 | #include <linux/list.h> | ||
| 15 | #include <linux/path.h> /* struct path */ | ||
| 16 | #include <linux/spinlock.h> | ||
| 17 | #include <linux/types.h> | ||
| 18 | |||
| 19 | #include <asm/atomic.h> | ||
| 20 | |||
| 21 | /* | ||
| 22 | * IN_* from inotfy.h lines up EXACTLY with FS_*, this is so we can easily | ||
| 23 | * convert between them. dnotify only needs conversion at watch creation | ||
| 24 | * so no perf loss there. fanotify isn't defined yet, so it can use the | ||
| 25 | * wholes if it needs more events. | ||
| 26 | */ | ||
| 27 | #define FS_ACCESS 0x00000001 /* File was accessed */ | ||
| 28 | #define FS_MODIFY 0x00000002 /* File was modified */ | ||
| 29 | #define FS_ATTRIB 0x00000004 /* Metadata changed */ | ||
| 30 | #define FS_CLOSE_WRITE 0x00000008 /* Writtable file was closed */ | ||
| 31 | #define FS_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */ | ||
| 32 | #define FS_OPEN 0x00000020 /* File was opened */ | ||
| 33 | #define FS_MOVED_FROM 0x00000040 /* File was moved from X */ | ||
| 34 | #define FS_MOVED_TO 0x00000080 /* File was moved to Y */ | ||
| 35 | #define FS_CREATE 0x00000100 /* Subfile was created */ | ||
| 36 | #define FS_DELETE 0x00000200 /* Subfile was deleted */ | ||
| 37 | #define FS_DELETE_SELF 0x00000400 /* Self was deleted */ | ||
| 38 | #define FS_MOVE_SELF 0x00000800 /* Self was moved */ | ||
| 39 | |||
| 40 | #define FS_UNMOUNT 0x00002000 /* inode on umount fs */ | ||
| 41 | #define FS_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ | ||
| 42 | #define FS_IN_IGNORED 0x00008000 /* last inotify event here */ | ||
| 43 | |||
| 44 | #define FS_IN_ISDIR 0x40000000 /* event occurred against dir */ | ||
| 45 | #define FS_IN_ONESHOT 0x80000000 /* only send event once */ | ||
| 46 | |||
| 47 | #define FS_DN_RENAME 0x10000000 /* file renamed */ | ||
| 48 | #define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */ | ||
| 49 | |||
| 50 | /* This inode cares about things that happen to its children. Always set for | ||
| 51 | * dnotify and inotify. */ | ||
| 52 | #define FS_EVENT_ON_CHILD 0x08000000 | ||
| 53 | |||
| 54 | /* This is a list of all events that may get sent to a parernt based on fs event | ||
| 55 | * happening to inodes inside that directory */ | ||
| 56 | #define FS_EVENTS_POSS_ON_CHILD (FS_ACCESS | FS_MODIFY | FS_ATTRIB |\ | ||
| 57 | FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | FS_OPEN |\ | ||
| 58 | FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE |\ | ||
| 59 | FS_DELETE) | ||
| 60 | |||
| 61 | /* listeners that hard code group numbers near the top */ | ||
| 62 | #define DNOTIFY_GROUP_NUM UINT_MAX | ||
| 63 | #define INOTIFY_GROUP_NUM (DNOTIFY_GROUP_NUM-1) | ||
| 64 | |||
| 65 | struct fsnotify_group; | ||
| 66 | struct fsnotify_event; | ||
| 67 | struct fsnotify_mark_entry; | ||
| 68 | struct fsnotify_event_private_data; | ||
| 69 | |||
| 70 | /* | ||
| 71 | * Each group much define these ops. The fsnotify infrastructure will call | ||
| 72 | * these operations for each relevant group. | ||
| 73 | * | ||
| 74 | * should_send_event - given a group, inode, and mask this function determines | ||
| 75 | * if the group is interested in this event. | ||
| 76 | * handle_event - main call for a group to handle an fs event | ||
| 77 | * free_group_priv - called when a group refcnt hits 0 to clean up the private union | ||
| 78 | * freeing-mark - this means that a mark has been flagged to die when everything | ||
| 79 | * finishes using it. The function is supplied with what must be a | ||
| 80 | * valid group and inode to use to clean up. | ||
| 81 | */ | ||
| 82 | struct fsnotify_ops { | ||
| 83 | bool (*should_send_event)(struct fsnotify_group *group, struct inode *inode, __u32 mask); | ||
| 84 | int (*handle_event)(struct fsnotify_group *group, struct fsnotify_event *event); | ||
| 85 | void (*free_group_priv)(struct fsnotify_group *group); | ||
| 86 | void (*freeing_mark)(struct fsnotify_mark_entry *entry, struct fsnotify_group *group); | ||
| 87 | void (*free_event_priv)(struct fsnotify_event_private_data *priv); | ||
| 88 | }; | ||
| 89 | |||
| 90 | /* | ||
| 91 | * A group is a "thing" that wants to receive notification about filesystem | ||
| 92 | * events. The mask holds the subset of event types this group cares about. | ||
| 93 | * refcnt on a group is up to the implementor and at any moment if it goes 0 | ||
| 94 | * everything will be cleaned up. | ||
| 95 | */ | ||
| 96 | struct fsnotify_group { | ||
| 97 | /* | ||
| 98 | * global list of all groups receiving events from fsnotify. | ||
| 99 | * anchored by fsnotify_groups and protected by either fsnotify_grp_mutex | ||
| 100 | * or fsnotify_grp_srcu depending on write vs read. | ||
| 101 | */ | ||
| 102 | struct list_head group_list; | ||
| 103 | |||
| 104 | /* | ||
| 105 | * Defines all of the event types in which this group is interested. | ||
| 106 | * This mask is a bitwise OR of the FS_* events from above. Each time | ||
| 107 | * this mask changes for a group (if it changes) the correct functions | ||
| 108 | * must be called to update the global structures which indicate global | ||
| 109 | * interest in event types. | ||
| 110 | */ | ||
| 111 | __u32 mask; | ||
| 112 | |||
| 113 | /* | ||
| 114 | * How the refcnt is used is up to each group. When the refcnt hits 0 | ||
| 115 | * fsnotify will clean up all of the resources associated with this group. | ||
| 116 | * As an example, the dnotify group will always have a refcnt=1 and that | ||
| 117 | * will never change. Inotify, on the other hand, has a group per | ||
| 118 | * inotify_init() and the refcnt will hit 0 only when that fd has been | ||
| 119 | * closed. | ||
| 120 | */ | ||
| 121 | atomic_t refcnt; /* things with interest in this group */ | ||
| 122 | unsigned int group_num; /* simply prevents accidental group collision */ | ||
| 123 | |||
| 124 | const struct fsnotify_ops *ops; /* how this group handles things */ | ||
| 125 | |||
| 126 | /* needed to send notification to userspace */ | ||
| 127 | struct mutex notification_mutex; /* protect the notification_list */ | ||
| 128 | struct list_head notification_list; /* list of event_holder this group needs to send to userspace */ | ||
| 129 | wait_queue_head_t notification_waitq; /* read() on the notification file blocks on this waitq */ | ||
| 130 | unsigned int q_len; /* events on the queue */ | ||
| 131 | unsigned int max_events; /* maximum events allowed on the list */ | ||
| 132 | |||
| 133 | /* stores all fastapth entries assoc with this group so they can be cleaned on unregister */ | ||
| 134 | spinlock_t mark_lock; /* protect mark_entries list */ | ||
| 135 | atomic_t num_marks; /* 1 for each mark entry and 1 for not being | ||
| 136 | * past the point of no return when freeing | ||
| 137 | * a group */ | ||
| 138 | struct list_head mark_entries; /* all inode mark entries for this group */ | ||
| 139 | |||
| 140 | /* prevents double list_del of group_list. protected by global fsnotify_grp_mutex */ | ||
| 141 | bool on_group_list; | ||
| 142 | |||
| 143 | /* groups can define private fields here or use the void *private */ | ||
| 144 | union { | ||
| 145 | void *private; | ||
| 146 | #ifdef CONFIG_INOTIFY_USER | ||
| 147 | struct inotify_group_private_data { | ||
| 148 | spinlock_t idr_lock; | ||
| 149 | struct idr idr; | ||
| 150 | u32 last_wd; | ||
| 151 | struct fasync_struct *fa; /* async notification */ | ||
| 152 | struct user_struct *user; | ||
| 153 | } inotify_data; | ||
| 154 | #endif | ||
| 155 | }; | ||
| 156 | }; | ||
| 157 | |||
| 158 | /* | ||
| 159 | * A single event can be queued in multiple group->notification_lists. | ||
| 160 | * | ||
| 161 | * each group->notification_list will point to an event_holder which in turns points | ||
| 162 | * to the actual event that needs to be sent to userspace. | ||
| 163 | * | ||
| 164 | * Seemed cheaper to create a refcnt'd event and a small holder for every group | ||
| 165 | * than create a different event for every group | ||
| 166 | * | ||
| 167 | */ | ||
| 168 | struct fsnotify_event_holder { | ||
| 169 | struct fsnotify_event *event; | ||
| 170 | struct list_head event_list; | ||
| 171 | }; | ||
| 172 | |||
| 173 | /* | ||
| 174 | * Inotify needs to tack data onto an event. This struct lets us later find the | ||
| 175 | * correct private data of the correct group. | ||
| 176 | */ | ||
| 177 | struct fsnotify_event_private_data { | ||
| 178 | struct fsnotify_group *group; | ||
| 179 | struct list_head event_list; | ||
| 180 | }; | ||
| 181 | |||
| 182 | /* | ||
| 183 | * all of the information about the original object we want to now send to | ||
| 184 | * a group. If you want to carry more info from the accessing task to the | ||
| 185 | * listener this structure is where you need to be adding fields. | ||
| 186 | */ | ||
| 187 | struct fsnotify_event { | ||
| 188 | /* | ||
| 189 | * If we create an event we are also likely going to need a holder | ||
| 190 | * to link to a group. So embed one holder in the event. Means only | ||
| 191 | * one allocation for the common case where we only have one group | ||
| 192 | */ | ||
| 193 | struct fsnotify_event_holder holder; | ||
| 194 | spinlock_t lock; /* protection for the associated event_holder and private_list */ | ||
| 195 | /* to_tell may ONLY be dereferenced during handle_event(). */ | ||
| 196 | struct inode *to_tell; /* either the inode the event happened to or its parent */ | ||
| 197 | /* | ||
| 198 | * depending on the event type we should have either a path or inode | ||
| 199 | * We hold a reference on path, but NOT on inode. Since we have the ref on | ||
| 200 | * the path, it may be dereferenced at any point during this object's | ||
| 201 | * lifetime. That reference is dropped when this object's refcnt hits | ||
| 202 | * 0. If this event contains an inode instead of a path, the inode may | ||
| 203 | * ONLY be used during handle_event(). | ||
| 204 | */ | ||
| 205 | union { | ||
| 206 | struct path path; | ||
| 207 | struct inode *inode; | ||
| 208 | }; | ||
| 209 | /* when calling fsnotify tell it if the data is a path or inode */ | ||
| 210 | #define FSNOTIFY_EVENT_NONE 0 | ||
| 211 | #define FSNOTIFY_EVENT_PATH 1 | ||
| 212 | #define FSNOTIFY_EVENT_INODE 2 | ||
| 213 | #define FSNOTIFY_EVENT_FILE 3 | ||
| 214 | int data_type; /* which of the above union we have */ | ||
| 215 | atomic_t refcnt; /* how many groups still are using/need to send this event */ | ||
| 216 | __u32 mask; /* the type of access, bitwise OR for FS_* event types */ | ||
| 217 | |||
| 218 | u32 sync_cookie; /* used to corrolate events, namely inotify mv events */ | ||
| 219 | char *file_name; | ||
| 220 | size_t name_len; | ||
| 221 | |||
| 222 | struct list_head private_data_list; /* groups can store private data here */ | ||
| 223 | }; | ||
| 224 | |||
| 225 | /* | ||
| 226 | * a mark is simply an entry attached to an in core inode which allows an | ||
| 227 | * fsnotify listener to indicate they are either no longer interested in events | ||
| 228 | * of a type matching mask or only interested in those events. | ||
| 229 | * | ||
| 230 | * these are flushed when an inode is evicted from core and may be flushed | ||
| 231 | * when the inode is modified (as seen by fsnotify_access). Some fsnotify users | ||
| 232 | * (such as dnotify) will flush these when the open fd is closed and not at | ||
| 233 | * inode eviction or modification. | ||
| 234 | */ | ||
| 235 | struct fsnotify_mark_entry { | ||
| 236 | __u32 mask; /* mask this mark entry is for */ | ||
| 237 | /* we hold ref for each i_list and g_list. also one ref for each 'thing' | ||
| 238 | * in kernel that found and may be using this mark. */ | ||
| 239 | atomic_t refcnt; /* active things looking at this mark */ | ||
| 240 | struct inode *inode; /* inode this entry is associated with */ | ||
| 241 | struct fsnotify_group *group; /* group this mark entry is for */ | ||
| 242 | struct hlist_node i_list; /* list of mark_entries by inode->i_fsnotify_mark_entries */ | ||
| 243 | struct list_head g_list; /* list of mark_entries by group->i_fsnotify_mark_entries */ | ||
| 244 | spinlock_t lock; /* protect group, inode, and killme */ | ||
| 245 | struct list_head free_i_list; /* tmp list used when freeing this mark */ | ||
| 246 | struct list_head free_g_list; /* tmp list used when freeing this mark */ | ||
| 247 | void (*free_mark)(struct fsnotify_mark_entry *entry); /* called on final put+free */ | ||
| 248 | }; | ||
| 249 | |||
| 250 | #ifdef CONFIG_FSNOTIFY | ||
| 251 | |||
| 252 | /* called from the vfs helpers */ | ||
| 253 | |||
| 254 | /* main fsnotify call to send events */ | ||
| 255 | extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, | ||
| 256 | const char *name, u32 cookie); | ||
| 257 | extern void __fsnotify_parent(struct dentry *dentry, __u32 mask); | ||
| 258 | extern void __fsnotify_inode_delete(struct inode *inode); | ||
| 259 | extern u32 fsnotify_get_cookie(void); | ||
| 260 | |||
| 261 | static inline int fsnotify_inode_watches_children(struct inode *inode) | ||
| 262 | { | ||
| 263 | /* FS_EVENT_ON_CHILD is set if the inode may care */ | ||
| 264 | if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD)) | ||
| 265 | return 0; | ||
| 266 | /* this inode might care about child events, does it care about the | ||
| 267 | * specific set of events that can happen on a child? */ | ||
| 268 | return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD; | ||
| 269 | } | ||
| 270 | |||
| 271 | /* | ||
| 272 | * Update the dentry with a flag indicating the interest of its parent to receive | ||
| 273 | * filesystem events when those events happens to this dentry->d_inode. | ||
| 274 | */ | ||
| 275 | static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) | ||
| 276 | { | ||
| 277 | struct dentry *parent; | ||
| 278 | |||
| 279 | assert_spin_locked(&dcache_lock); | ||
| 280 | assert_spin_locked(&dentry->d_lock); | ||
| 281 | |||
| 282 | parent = dentry->d_parent; | ||
| 283 | if (fsnotify_inode_watches_children(parent->d_inode)) | ||
| 284 | dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; | ||
| 285 | else | ||
| 286 | dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; | ||
| 287 | } | ||
| 288 | |||
| 289 | /* | ||
| 290 | * fsnotify_d_instantiate - instantiate a dentry for inode | ||
| 291 | * Called with dcache_lock held. | ||
| 292 | */ | ||
| 293 | static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) | ||
| 294 | { | ||
| 295 | if (!inode) | ||
| 296 | return; | ||
| 297 | |||
| 298 | assert_spin_locked(&dcache_lock); | ||
| 299 | |||
| 300 | spin_lock(&dentry->d_lock); | ||
| 301 | __fsnotify_update_dcache_flags(dentry); | ||
| 302 | spin_unlock(&dentry->d_lock); | ||
| 303 | } | ||
| 304 | |||
| 305 | /* called from fsnotify listeners, such as fanotify or dnotify */ | ||
| 306 | |||
| 307 | /* must call when a group changes its ->mask */ | ||
| 308 | extern void fsnotify_recalc_global_mask(void); | ||
| 309 | /* get a reference to an existing or create a new group */ | ||
| 310 | extern struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num, | ||
| 311 | __u32 mask, | ||
| 312 | const struct fsnotify_ops *ops); | ||
| 313 | /* run all marks associated with this group and update group->mask */ | ||
| 314 | extern void fsnotify_recalc_group_mask(struct fsnotify_group *group); | ||
| 315 | /* drop reference on a group from fsnotify_obtain_group */ | ||
| 316 | extern void fsnotify_put_group(struct fsnotify_group *group); | ||
| 317 | |||
| 318 | /* take a reference to an event */ | ||
| 319 | extern void fsnotify_get_event(struct fsnotify_event *event); | ||
| 320 | extern void fsnotify_put_event(struct fsnotify_event *event); | ||
| 321 | /* find private data previously attached to an event and unlink it */ | ||
| 322 | extern struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnotify_group *group, | ||
| 323 | struct fsnotify_event *event); | ||
| 324 | |||
| 325 | /* attach the event to the group notification queue */ | ||
| 326 | extern int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event, | ||
| 327 | struct fsnotify_event_private_data *priv); | ||
| 328 | /* true if the group notification queue is empty */ | ||
| 329 | extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group); | ||
| 330 | /* return, but do not dequeue the first event on the notification queue */ | ||
| 331 | extern struct fsnotify_event *fsnotify_peek_notify_event(struct fsnotify_group *group); | ||
| 332 | /* return AND dequeue the first event on the notification queue */ | ||
| 333 | extern struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group); | ||
| 334 | |||
| 335 | /* functions used to manipulate the marks attached to inodes */ | ||
| 336 | |||
| 337 | /* run all marks associated with an inode and update inode->i_fsnotify_mask */ | ||
| 338 | extern void fsnotify_recalc_inode_mask(struct inode *inode); | ||
| 339 | extern void fsnotify_init_mark(struct fsnotify_mark_entry *entry, void (*free_mark)(struct fsnotify_mark_entry *entry)); | ||
| 340 | /* find (and take a reference) to a mark associated with group and inode */ | ||
| 341 | extern struct fsnotify_mark_entry *fsnotify_find_mark_entry(struct fsnotify_group *group, struct inode *inode); | ||
| 342 | /* attach the mark to both the group and the inode */ | ||
| 343 | extern int fsnotify_add_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group, struct inode *inode); | ||
| 344 | /* given a mark, flag it to be freed when all references are dropped */ | ||
| 345 | extern void fsnotify_destroy_mark_by_entry(struct fsnotify_mark_entry *entry); | ||
| 346 | /* run all the marks in a group, and flag them to be freed */ | ||
| 347 | extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group); | ||
| 348 | extern void fsnotify_get_mark(struct fsnotify_mark_entry *entry); | ||
| 349 | extern void fsnotify_put_mark(struct fsnotify_mark_entry *entry); | ||
| 350 | extern void fsnotify_unmount_inodes(struct list_head *list); | ||
| 351 | |||
| 352 | /* put here because inotify does some weird stuff when destroying watches */ | ||
| 353 | extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, | ||
| 354 | void *data, int data_is, const char *name, | ||
| 355 | u32 cookie); | ||
| 356 | |||
| 357 | #else | ||
| 358 | |||
| 359 | static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, | ||
| 360 | const char *name, u32 cookie) | ||
| 361 | {} | ||
| 362 | |||
| 363 | static inline void __fsnotify_parent(struct dentry *dentry, __u32 mask) | ||
| 364 | {} | ||
| 365 | |||
| 366 | static inline void __fsnotify_inode_delete(struct inode *inode) | ||
| 367 | {} | ||
| 368 | |||
| 369 | static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) | ||
| 370 | {} | ||
| 371 | |||
| 372 | static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) | ||
| 373 | {} | ||
| 374 | |||
| 375 | static inline u32 fsnotify_get_cookie(void) | ||
| 376 | { | ||
| 377 | return 0; | ||
| 378 | } | ||
| 379 | |||
| 380 | static inline void fsnotify_unmount_inodes(struct list_head *list) | ||
| 381 | {} | ||
| 382 | |||
| 383 | #endif /* CONFIG_FSNOTIFY */ | ||
| 384 | |||
| 385 | #endif /* __KERNEL __ */ | ||
| 386 | |||
| 387 | #endif /* __LINUX_FSNOTIFY_BACKEND_H */ | ||
