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authorAmir Goldstein <amir73il@gmail.com>2018-06-23 10:54:49 -0400
committerJan Kara <jack@suse.cz>2018-06-27 07:45:05 -0400
commit36f10f55ff1d2867bfc48ed898a9cc0dc6b49dd2 (patch)
tree0b7a840c5c8e0b2bd44aeca2c21a144b25d89457
parentb812a9f5896379b6cff2ac168ddb5b89037d8e78 (diff)
fsnotify: let connector point to an abstract object
Make the code to attach/detach a connector to object more generic by letting the fsnotify connector point to an abstract fsnotify_connp_t. Code that needs to dereference an inode or mount object now uses the helpers fsnotify_conn_{inode,mount}. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
-rw-r--r--fs/notify/fdinfo.c8
-rw-r--r--fs/notify/fsnotify.h10
-rw-r--r--fs/notify/mark.c32
-rw-r--r--include/linux/fsnotify_backend.h15
-rw-r--r--kernel/audit_tree.c17
5 files changed, 45 insertions, 37 deletions
diff --git a/fs/notify/fdinfo.c b/fs/notify/fdinfo.c
index 10aac1942c9f..86fcf5814279 100644
--- a/fs/notify/fdinfo.c
+++ b/fs/notify/fdinfo.c
@@ -15,7 +15,7 @@
15#include <linux/exportfs.h> 15#include <linux/exportfs.h>
16 16
17#include "inotify/inotify.h" 17#include "inotify/inotify.h"
18#include "../fs/mount.h" 18#include "fsnotify.h"
19 19
20#if defined(CONFIG_PROC_FS) 20#if defined(CONFIG_PROC_FS)
21 21
@@ -81,7 +81,7 @@ static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
81 return; 81 return;
82 82
83 inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark); 83 inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
84 inode = igrab(mark->connector->inode); 84 inode = igrab(fsnotify_conn_inode(mark->connector));
85 if (inode) { 85 if (inode) {
86 /* 86 /*
87 * IN_ALL_EVENTS represents all of the mask bits 87 * IN_ALL_EVENTS represents all of the mask bits
@@ -117,7 +117,7 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
117 mflags |= FAN_MARK_IGNORED_SURV_MODIFY; 117 mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
118 118
119 if (mark->connector->type == FSNOTIFY_OBJ_TYPE_INODE) { 119 if (mark->connector->type == FSNOTIFY_OBJ_TYPE_INODE) {
120 inode = igrab(mark->connector->inode); 120 inode = igrab(fsnotify_conn_inode(mark->connector));
121 if (!inode) 121 if (!inode)
122 return; 122 return;
123 seq_printf(m, "fanotify ino:%lx sdev:%x mflags:%x mask:%x ignored_mask:%x ", 123 seq_printf(m, "fanotify ino:%lx sdev:%x mflags:%x mask:%x ignored_mask:%x ",
@@ -127,7 +127,7 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
127 seq_putc(m, '\n'); 127 seq_putc(m, '\n');
128 iput(inode); 128 iput(inode);
129 } else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) { 129 } else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
130 struct mount *mnt = real_mount(mark->connector->mnt); 130 struct mount *mnt = fsnotify_conn_mount(mark->connector);
131 131
132 seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n", 132 seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n",
133 mnt->mnt_id, mflags, mark->mask, mark->ignored_mask); 133 mnt->mnt_id, mflags, mark->mask, mark->ignored_mask);
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h
index caeee042d1cc..7902653dd577 100644
--- a/fs/notify/fsnotify.h
+++ b/fs/notify/fsnotify.h
@@ -9,14 +9,16 @@
9 9
10#include "../mount.h" 10#include "../mount.h"
11 11
12static inline struct inode *fsnotify_obj_inode(fsnotify_connp_t *connp) 12static inline struct inode *fsnotify_conn_inode(
13 struct fsnotify_mark_connector *conn)
13{ 14{
14 return container_of(connp, struct inode, i_fsnotify_marks); 15 return container_of(conn->obj, struct inode, i_fsnotify_marks);
15} 16}
16 17
17static inline struct mount *fsnotify_obj_mount(fsnotify_connp_t *connp) 18static inline struct mount *fsnotify_conn_mount(
19 struct fsnotify_mark_connector *conn)
18{ 20{
19 return container_of(connp, struct mount, mnt_fsnotify_marks); 21 return container_of(conn->obj, struct mount, mnt_fsnotify_marks);
20} 22}
21 23
22/* destroy all events sitting in this groups notification queue */ 24/* destroy all events sitting in this groups notification queue */
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 7abb73b5beba..959bc73aaae7 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -120,14 +120,14 @@ static void __fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
120 new_mask |= mark->mask; 120 new_mask |= mark->mask;
121 } 121 }
122 if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) 122 if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
123 conn->inode->i_fsnotify_mask = new_mask; 123 fsnotify_conn_inode(conn)->i_fsnotify_mask = new_mask;
124 else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) 124 else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT)
125 real_mount(conn->mnt)->mnt_fsnotify_mask = new_mask; 125 fsnotify_conn_mount(conn)->mnt_fsnotify_mask = new_mask;
126} 126}
127 127
128/* 128/*
129 * Calculate mask of events for a list of marks. The caller must make sure 129 * Calculate mask of events for a list of marks. The caller must make sure
130 * connector and connector->inode cannot disappear under us. Callers achieve 130 * connector and connector->obj cannot disappear under us. Callers achieve
131 * this by holding a mark->lock or mark->group->mark_mutex for a mark on this 131 * this by holding a mark->lock or mark->group->mark_mutex for a mark on this
132 * list. 132 * list.
133 */ 133 */
@@ -140,7 +140,8 @@ void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
140 __fsnotify_recalc_mask(conn); 140 __fsnotify_recalc_mask(conn);
141 spin_unlock(&conn->lock); 141 spin_unlock(&conn->lock);
142 if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) 142 if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
143 __fsnotify_update_child_dentry_flags(conn->inode); 143 __fsnotify_update_child_dentry_flags(
144 fsnotify_conn_inode(conn));
144} 145}
145 146
146/* Free all connectors queued for freeing once SRCU period ends */ 147/* Free all connectors queued for freeing once SRCU period ends */
@@ -166,20 +167,20 @@ static struct inode *fsnotify_detach_connector_from_object(
166{ 167{
167 struct inode *inode = NULL; 168 struct inode *inode = NULL;
168 169
170 if (conn->type == FSNOTIFY_OBJ_TYPE_DETACHED)
171 return NULL;
172
169 if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) { 173 if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) {
170 inode = conn->inode; 174 inode = fsnotify_conn_inode(conn);
171 rcu_assign_pointer(inode->i_fsnotify_marks, NULL);
172 inode->i_fsnotify_mask = 0; 175 inode->i_fsnotify_mask = 0;
173 conn->inode = NULL;
174 conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
175 } else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) { 176 } else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
176 rcu_assign_pointer(real_mount(conn->mnt)->mnt_fsnotify_marks, 177 fsnotify_conn_mount(conn)->mnt_fsnotify_mask = 0;
177 NULL);
178 real_mount(conn->mnt)->mnt_fsnotify_mask = 0;
179 conn->mnt = NULL;
180 conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
181 } 178 }
182 179
180 rcu_assign_pointer(*(conn->obj), NULL);
181 conn->obj = NULL;
182 conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
183
183 return inode; 184 return inode;
184} 185}
185 186
@@ -448,10 +449,9 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp,
448 spin_lock_init(&conn->lock); 449 spin_lock_init(&conn->lock);
449 INIT_HLIST_HEAD(&conn->list); 450 INIT_HLIST_HEAD(&conn->list);
450 conn->type = type; 451 conn->type = type;
452 conn->obj = connp;
451 if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) 453 if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
452 inode = conn->inode = igrab(fsnotify_obj_inode(connp)); 454 inode = igrab(fsnotify_conn_inode(conn));
453 else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT)
454 conn->mnt = &fsnotify_obj_mount(connp)->mnt;
455 /* 455 /*
456 * cmpxchg() provides the barrier so that readers of *connp can see 456 * cmpxchg() provides the barrier so that readers of *connp can see
457 * only initialized structure 457 * only initialized structure
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 8efb8663453d..381cfb0e67fa 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -256,6 +256,13 @@ FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT)
256 for (type = 0; type < FSNOTIFY_OBJ_TYPE_COUNT; type++) 256 for (type = 0; type < FSNOTIFY_OBJ_TYPE_COUNT; type++)
257 257
258/* 258/*
259 * fsnotify_connp_t is what we embed in objects which connector can be attached
260 * to. fsnotify_connp_t * is how we refer from connector back to object.
261 */
262struct fsnotify_mark_connector;
263typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t;
264
265/*
259 * Inode / vfsmount point to this structure which tracks all marks attached to 266 * Inode / vfsmount point to this structure which tracks all marks attached to
260 * the inode / vfsmount. The reference to inode / vfsmount is held by this 267 * the inode / vfsmount. The reference to inode / vfsmount is held by this
261 * structure. We destroy this structure when there are no more marks attached 268 * structure. We destroy this structure when there are no more marks attached
@@ -264,17 +271,15 @@ FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT)
264struct fsnotify_mark_connector { 271struct fsnotify_mark_connector {
265 spinlock_t lock; 272 spinlock_t lock;
266 unsigned int type; /* Type of object [lock] */ 273 unsigned int type; /* Type of object [lock] */
267 union { /* Object pointer [lock] */ 274 union {
268 struct inode *inode; 275 /* Object pointer [lock] */
269 struct vfsmount *mnt; 276 fsnotify_connp_t *obj;
270 /* Used listing heads to free after srcu period expires */ 277 /* Used listing heads to free after srcu period expires */
271 struct fsnotify_mark_connector *destroy_next; 278 struct fsnotify_mark_connector *destroy_next;
272 }; 279 };
273 struct hlist_head list; 280 struct hlist_head list;
274}; 281};
275 282
276typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t;
277
278/* 283/*
279 * A mark is simply an object attached to an in core inode which allows an 284 * A mark is simply an object attached to an in core inode which allows an
280 * fsnotify listener to indicate they are either no longer interested in events 285 * fsnotify listener to indicate they are either no longer interested in events
diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index c99ebaae5abc..02feef939560 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -168,7 +168,8 @@ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock);
168/* Function to return search key in our hash from inode. */ 168/* Function to return search key in our hash from inode. */
169static unsigned long inode_to_key(const struct inode *inode) 169static unsigned long inode_to_key(const struct inode *inode)
170{ 170{
171 return (unsigned long)inode; 171 /* Use address pointed to by connector->obj as the key */
172 return (unsigned long)&inode->i_fsnotify_marks;
172} 173}
173 174
174/* 175/*
@@ -183,7 +184,7 @@ static unsigned long chunk_to_key(struct audit_chunk *chunk)
183 */ 184 */
184 if (WARN_ON_ONCE(!chunk->mark.connector)) 185 if (WARN_ON_ONCE(!chunk->mark.connector))
185 return 0; 186 return 0;
186 return (unsigned long)chunk->mark.connector->inode; 187 return (unsigned long)chunk->mark.connector->obj;
187} 188}
188 189
189static inline struct list_head *chunk_hash(unsigned long key) 190static inline struct list_head *chunk_hash(unsigned long key)
@@ -258,7 +259,7 @@ static void untag_chunk(struct node *p)
258 spin_lock(&entry->lock); 259 spin_lock(&entry->lock);
259 /* 260 /*
260 * mark_mutex protects mark from getting detached and thus also from 261 * mark_mutex protects mark from getting detached and thus also from
261 * mark->connector->inode getting NULL. 262 * mark->connector->obj getting NULL.
262 */ 263 */
263 if (chunk->dead || !(entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { 264 if (chunk->dead || !(entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
264 spin_unlock(&entry->lock); 265 spin_unlock(&entry->lock);
@@ -288,8 +289,8 @@ static void untag_chunk(struct node *p)
288 if (!new) 289 if (!new)
289 goto Fallback; 290 goto Fallback;
290 291
291 if (fsnotify_add_inode_mark_locked(&new->mark, entry->connector->inode, 292 if (fsnotify_add_mark_locked(&new->mark, entry->connector->obj,
292 1)) { 293 FSNOTIFY_OBJ_TYPE_INODE, 1)) {
293 fsnotify_put_mark(&new->mark); 294 fsnotify_put_mark(&new->mark);
294 goto Fallback; 295 goto Fallback;
295 } 296 }
@@ -423,7 +424,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
423 spin_lock(&old_entry->lock); 424 spin_lock(&old_entry->lock);
424 /* 425 /*
425 * mark_mutex protects mark from getting detached and thus also from 426 * mark_mutex protects mark from getting detached and thus also from
426 * mark->connector->inode getting NULL. 427 * mark->connector->obj getting NULL.
427 */ 428 */
428 if (!(old_entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { 429 if (!(old_entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
429 /* old_entry is being shot, lets just lie */ 430 /* old_entry is being shot, lets just lie */
@@ -434,8 +435,8 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
434 return -ENOENT; 435 return -ENOENT;
435 } 436 }
436 437
437 if (fsnotify_add_inode_mark_locked(chunk_entry, 438 if (fsnotify_add_mark_locked(chunk_entry, old_entry->connector->obj,
438 old_entry->connector->inode, 1)) { 439 FSNOTIFY_OBJ_TYPE_INODE, 1)) {
439 spin_unlock(&old_entry->lock); 440 spin_unlock(&old_entry->lock);
440 mutex_unlock(&old_entry->group->mark_mutex); 441 mutex_unlock(&old_entry->group->mark_mutex);
441 fsnotify_put_mark(chunk_entry); 442 fsnotify_put_mark(chunk_entry);