fsnotify: store struct file not struct path

Al explains that calling dentry_open() with a mnt/dentry pair is only
garunteed to be safe if they are already used in an open struct file.  To
make sure this is the case don't store and use a struct path in fsnotify,
always use a struct file.

Signed-off-by: Eric Paris <eparis@redhat.com>
This commit is contained in:
Eric Paris
2010-07-28 10:18:37 -04:00
parent f70ab54cc6
commit 3bcf3860a4
8 changed files with 56 additions and 63 deletions

View File

@@ -17,9 +17,9 @@ static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new)
old->data_type == new->data_type &&
old->tgid == new->tgid) {
switch (old->data_type) {
case (FSNOTIFY_EVENT_PATH):
if ((old->path.mnt == new->path.mnt) &&
(old->path.dentry == new->path.dentry))
case (FSNOTIFY_EVENT_FILE):
if ((old->file->f_path.mnt == new->file->f_path.mnt) &&
(old->file->f_path.dentry == new->file->f_path.dentry))
return true;
case (FSNOTIFY_EVENT_NONE):
return true;
@@ -226,7 +226,7 @@ static bool fanotify_should_send_event(struct fsnotify_group *group, struct inod
return false;
/* if we don't have enough info to send an event to userspace say no */
if (data_type != FSNOTIFY_EVENT_PATH)
if (data_type != FSNOTIFY_EVENT_FILE)
return false;
if (mnt)

View File

@@ -65,7 +65,7 @@ static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
if (client_fd < 0)
return client_fd;
if (event->data_type != FSNOTIFY_EVENT_PATH) {
if (event->data_type != FSNOTIFY_EVENT_FILE) {
WARN_ON(1);
put_unused_fd(client_fd);
return -EINVAL;
@@ -75,8 +75,8 @@ static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
* we need a new file handle for the userspace program so it can read even if it was
* originally opened O_WRONLY.
*/
dentry = dget(event->path.dentry);
mnt = mntget(event->path.mnt);
dentry = dget(event->file->f_path.dentry);
mnt = mntget(event->file->f_path.mnt);
/* it's possible this event was an overflow event. in that case dentry and mnt
* are NULL; That's fine, just don't call dentry open */
if (dentry && mnt)

View File

@@ -84,7 +84,7 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
}
/* Notify this dentry's parent about a child's events. */
void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
void __fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask)
{
struct dentry *parent;
struct inode *p_inode;
@@ -92,7 +92,7 @@ void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
bool should_update_children = false;
if (!dentry)
dentry = path->dentry;
dentry = file->f_path.dentry;
if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))
return;
@@ -124,8 +124,8 @@ void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
* specifies these are events which came from a child. */
mask |= FS_EVENT_ON_CHILD;
if (path)
fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH,
if (file)
fsnotify(p_inode, mask, file, FSNOTIFY_EVENT_FILE,
dentry->d_name.name, 0);
else
fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
@@ -154,10 +154,10 @@ void __fsnotify_flush_ignored_mask(struct inode *inode, void *data, int data_is)
spin_unlock(&inode->i_lock);
}
if (data_is == FSNOTIFY_EVENT_PATH) {
if (data_is == FSNOTIFY_EVENT_FILE) {
struct vfsmount *mnt;
mnt = ((struct path *)data)->mnt;
mnt = ((struct file *)data)->f_path.mnt;
if (mnt && !hlist_empty(&mnt->mnt_fsnotify_marks)) {
spin_lock(&mnt->mnt_root->d_lock);
hlist_for_each_entry(mark, node, &mnt->mnt_fsnotify_marks, m.m_list) {
@@ -228,8 +228,8 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
!(test_mask & fsnotify_vfsmount_mask))
return 0;
if (data_is == FSNOTIFY_EVENT_PATH)
mnt = ((struct path *)data)->mnt;
if (data_is == FSNOTIFY_EVENT_FILE)
mnt = ((struct file *)data)->f_path.mnt;
/* if this inode's directed listeners don't care and nothing on the vfsmount
* listeners list cares, nothing to do */

View File

@@ -52,9 +52,9 @@ static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new
!strcmp(old->file_name, new->file_name))
return true;
break;
case (FSNOTIFY_EVENT_PATH):
if ((old->path.mnt == new->path.mnt) &&
(old->path.dentry == new->path.dentry))
case (FSNOTIFY_EVENT_FILE):
if ((old->file->f_path.mnt == new->file->f_path.mnt) &&
(old->file->f_path.dentry == new->file->f_path.dentry))
return true;
break;
case (FSNOTIFY_EVENT_NONE):
@@ -165,10 +165,10 @@ static bool inotify_should_send_event(struct fsnotify_group *group, struct inode
send = (fsn_mark->mask & mask);
if (send && (fsn_mark->mask & FS_EXCL_UNLINK) &&
(data_type == FSNOTIFY_EVENT_PATH)) {
struct path *path = data;
(data_type == FSNOTIFY_EVENT_FILE)) {
struct file *file = data;
if (d_unlinked(path->dentry))
if (d_unlinked(file->f_path.dentry))
send = false;
}

View File

@@ -31,6 +31,7 @@
* allocated and used.
*/
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -89,8 +90,8 @@ void fsnotify_put_event(struct fsnotify_event *event)
if (atomic_dec_and_test(&event->refcnt)) {
pr_debug("%s: event=%p\n", __func__, event);
if (event->data_type == FSNOTIFY_EVENT_PATH)
path_put(&event->path);
if (event->data_type == FSNOTIFY_EVENT_FILE)
fput(event->file);
BUG_ON(!list_empty(&event->private_data_list));
@@ -375,8 +376,8 @@ struct fsnotify_event *fsnotify_clone_event(struct fsnotify_event *old_event)
}
}
event->tgid = get_pid(old_event->tgid);
if (event->data_type == FSNOTIFY_EVENT_PATH)
path_get(&event->path);
if (event->data_type == FSNOTIFY_EVENT_FILE)
get_file(event->file);
return event;
}
@@ -423,11 +424,9 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
event->data_type = data_type;
switch (data_type) {
case FSNOTIFY_EVENT_PATH: {
struct path *path = data;
event->path.dentry = path->dentry;
event->path.mnt = path->mnt;
path_get(&event->path);
case FSNOTIFY_EVENT_FILE: {
event->file = data;
get_file(event->file);
break;
}
case FSNOTIFY_EVENT_INODE:
@@ -435,8 +434,7 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
break;
case FSNOTIFY_EVENT_NONE:
event->inode = NULL;
event->path.dentry = NULL;
event->path.mnt = NULL;
event->file = NULL;
break;
default:
BUG();