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:
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f70ab54cc6
Коммит
3bcf3860a4
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@ -17,9 +17,9 @@ static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new)
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old->data_type == new->data_type &&
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old->tgid == new->tgid) {
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switch (old->data_type) {
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case (FSNOTIFY_EVENT_PATH):
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if ((old->path.mnt == new->path.mnt) &&
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(old->path.dentry == new->path.dentry))
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case (FSNOTIFY_EVENT_FILE):
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if ((old->file->f_path.mnt == new->file->f_path.mnt) &&
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(old->file->f_path.dentry == new->file->f_path.dentry))
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return true;
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case (FSNOTIFY_EVENT_NONE):
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return true;
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@ -226,7 +226,7 @@ static bool fanotify_should_send_event(struct fsnotify_group *group, struct inod
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return false;
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/* if we don't have enough info to send an event to userspace say no */
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if (data_type != FSNOTIFY_EVENT_PATH)
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if (data_type != FSNOTIFY_EVENT_FILE)
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return false;
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if (mnt)
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@ -65,7 +65,7 @@ static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
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if (client_fd < 0)
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return client_fd;
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if (event->data_type != FSNOTIFY_EVENT_PATH) {
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if (event->data_type != FSNOTIFY_EVENT_FILE) {
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WARN_ON(1);
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put_unused_fd(client_fd);
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return -EINVAL;
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@ -75,8 +75,8 @@ static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
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* we need a new file handle for the userspace program so it can read even if it was
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* originally opened O_WRONLY.
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*/
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dentry = dget(event->path.dentry);
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mnt = mntget(event->path.mnt);
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dentry = dget(event->file->f_path.dentry);
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mnt = mntget(event->file->f_path.mnt);
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/* it's possible this event was an overflow event. in that case dentry and mnt
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* are NULL; That's fine, just don't call dentry open */
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if (dentry && mnt)
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@ -84,7 +84,7 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
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}
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/* Notify this dentry's parent about a child's events. */
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void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
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void __fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask)
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{
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struct dentry *parent;
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struct inode *p_inode;
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@ -92,7 +92,7 @@ void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
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bool should_update_children = false;
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if (!dentry)
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dentry = path->dentry;
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dentry = file->f_path.dentry;
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if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))
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return;
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@ -124,8 +124,8 @@ void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
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* specifies these are events which came from a child. */
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mask |= FS_EVENT_ON_CHILD;
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if (path)
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fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH,
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if (file)
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fsnotify(p_inode, mask, file, FSNOTIFY_EVENT_FILE,
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dentry->d_name.name, 0);
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else
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fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
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@ -154,10 +154,10 @@ void __fsnotify_flush_ignored_mask(struct inode *inode, void *data, int data_is)
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spin_unlock(&inode->i_lock);
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}
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if (data_is == FSNOTIFY_EVENT_PATH) {
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if (data_is == FSNOTIFY_EVENT_FILE) {
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struct vfsmount *mnt;
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mnt = ((struct path *)data)->mnt;
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mnt = ((struct file *)data)->f_path.mnt;
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if (mnt && !hlist_empty(&mnt->mnt_fsnotify_marks)) {
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spin_lock(&mnt->mnt_root->d_lock);
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hlist_for_each_entry(mark, node, &mnt->mnt_fsnotify_marks, m.m_list) {
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@ -228,8 +228,8 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
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!(test_mask & fsnotify_vfsmount_mask))
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return 0;
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if (data_is == FSNOTIFY_EVENT_PATH)
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mnt = ((struct path *)data)->mnt;
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if (data_is == FSNOTIFY_EVENT_FILE)
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mnt = ((struct file *)data)->f_path.mnt;
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/* if this inode's directed listeners don't care and nothing on the vfsmount
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* listeners list cares, nothing to do */
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@ -52,9 +52,9 @@ static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new
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!strcmp(old->file_name, new->file_name))
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return true;
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break;
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case (FSNOTIFY_EVENT_PATH):
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if ((old->path.mnt == new->path.mnt) &&
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(old->path.dentry == new->path.dentry))
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case (FSNOTIFY_EVENT_FILE):
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if ((old->file->f_path.mnt == new->file->f_path.mnt) &&
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(old->file->f_path.dentry == new->file->f_path.dentry))
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return true;
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break;
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case (FSNOTIFY_EVENT_NONE):
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@ -165,10 +165,10 @@ static bool inotify_should_send_event(struct fsnotify_group *group, struct inode
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send = (fsn_mark->mask & mask);
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if (send && (fsn_mark->mask & FS_EXCL_UNLINK) &&
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(data_type == FSNOTIFY_EVENT_PATH)) {
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struct path *path = data;
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(data_type == FSNOTIFY_EVENT_FILE)) {
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struct file *file = data;
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if (d_unlinked(path->dentry))
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if (d_unlinked(file->f_path.dentry))
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send = false;
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}
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@ -31,6 +31,7 @@
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* allocated and used.
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*/
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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@ -89,8 +90,8 @@ void fsnotify_put_event(struct fsnotify_event *event)
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if (atomic_dec_and_test(&event->refcnt)) {
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pr_debug("%s: event=%p\n", __func__, event);
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if (event->data_type == FSNOTIFY_EVENT_PATH)
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path_put(&event->path);
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if (event->data_type == FSNOTIFY_EVENT_FILE)
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fput(event->file);
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BUG_ON(!list_empty(&event->private_data_list));
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@ -375,8 +376,8 @@ struct fsnotify_event *fsnotify_clone_event(struct fsnotify_event *old_event)
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}
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}
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event->tgid = get_pid(old_event->tgid);
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if (event->data_type == FSNOTIFY_EVENT_PATH)
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path_get(&event->path);
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if (event->data_type == FSNOTIFY_EVENT_FILE)
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get_file(event->file);
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return event;
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}
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@ -423,11 +424,9 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
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event->data_type = data_type;
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switch (data_type) {
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case FSNOTIFY_EVENT_PATH: {
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struct path *path = data;
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event->path.dentry = path->dentry;
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event->path.mnt = path->mnt;
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path_get(&event->path);
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case FSNOTIFY_EVENT_FILE: {
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event->file = data;
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get_file(event->file);
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break;
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}
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case FSNOTIFY_EVENT_INODE:
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@ -435,8 +434,7 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
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break;
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case FSNOTIFY_EVENT_NONE:
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event->inode = NULL;
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event->path.dentry = NULL;
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event->path.mnt = NULL;
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event->file = NULL;
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break;
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default:
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BUG();
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@ -26,19 +26,18 @@ static inline void fsnotify_d_instantiate(struct dentry *dentry,
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}
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/* Notify this dentry's parent about a child's events. */
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static inline void fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
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static inline void fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask)
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{
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if (!dentry)
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dentry = path->dentry;
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dentry = file->f_path.dentry;
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__fsnotify_parent(path, dentry, mask);
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__fsnotify_parent(file, dentry, mask);
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}
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/* simple call site for access decisions */
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static inline int fsnotify_perm(struct file *file, int mask)
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{
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struct path *path = &file->f_path;
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struct inode *inode = path->dentry->d_inode;
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struct inode *inode = file->f_path.dentry->d_inode;
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__u32 fsnotify_mask = 0;
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if (file->f_mode & FMODE_NONOTIFY)
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@ -52,7 +51,7 @@ static inline int fsnotify_perm(struct file *file, int mask)
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else
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BUG();
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return fsnotify(inode, fsnotify_mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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return fsnotify(inode, fsnotify_mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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}
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/*
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@ -187,16 +186,15 @@ static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
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*/
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static inline void fsnotify_access(struct file *file)
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{
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struct path *path = &file->f_path;
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struct inode *inode = path->dentry->d_inode;
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struct inode *inode = file->f_path.dentry->d_inode;
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__u32 mask = FS_ACCESS;
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if (S_ISDIR(inode->i_mode))
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mask |= FS_IN_ISDIR;
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if (!(file->f_mode & FMODE_NONOTIFY)) {
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fsnotify_parent(path, NULL, mask);
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fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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fsnotify_parent(file, NULL, mask);
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fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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}
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}
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@ -205,16 +203,15 @@ static inline void fsnotify_access(struct file *file)
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*/
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static inline void fsnotify_modify(struct file *file)
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{
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struct path *path = &file->f_path;
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struct inode *inode = path->dentry->d_inode;
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struct inode *inode = file->f_path.dentry->d_inode;
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__u32 mask = FS_MODIFY;
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if (S_ISDIR(inode->i_mode))
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mask |= FS_IN_ISDIR;
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if (!(file->f_mode & FMODE_NONOTIFY)) {
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fsnotify_parent(path, NULL, mask);
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fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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fsnotify_parent(file, NULL, mask);
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fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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}
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}
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@ -223,16 +220,15 @@ static inline void fsnotify_modify(struct file *file)
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*/
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static inline void fsnotify_open(struct file *file)
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{
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struct path *path = &file->f_path;
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struct inode *inode = path->dentry->d_inode;
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struct inode *inode = file->f_path.dentry->d_inode;
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__u32 mask = FS_OPEN;
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if (S_ISDIR(inode->i_mode))
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mask |= FS_IN_ISDIR;
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if (!(file->f_mode & FMODE_NONOTIFY)) {
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fsnotify_parent(path, NULL, mask);
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fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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fsnotify_parent(file, NULL, mask);
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fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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}
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}
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@ -241,7 +237,6 @@ static inline void fsnotify_open(struct file *file)
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*/
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static inline void fsnotify_close(struct file *file)
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{
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struct path *path = &file->f_path;
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struct inode *inode = file->f_path.dentry->d_inode;
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fmode_t mode = file->f_mode;
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__u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
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@ -250,8 +245,8 @@ static inline void fsnotify_close(struct file *file)
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mask |= FS_IN_ISDIR;
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if (!(file->f_mode & FMODE_NONOTIFY)) {
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fsnotify_parent(path, NULL, mask);
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fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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fsnotify_parent(file, NULL, mask);
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fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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}
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}
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@ -223,20 +223,20 @@ struct fsnotify_event {
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/* to_tell may ONLY be dereferenced during handle_event(). */
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struct inode *to_tell; /* either the inode the event happened to or its parent */
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/*
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* depending on the event type we should have either a path or inode
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* We hold a reference on path, but NOT on inode. Since we have the ref on
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* the path, it may be dereferenced at any point during this object's
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* depending on the event type we should have either a file or inode
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* We hold a reference on file, but NOT on inode. Since we have the ref on
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* the file, it may be dereferenced at any point during this object's
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* lifetime. That reference is dropped when this object's refcnt hits
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* 0. If this event contains an inode instead of a path, the inode may
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* 0. If this event contains an inode instead of a file, the inode may
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* ONLY be used during handle_event().
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*/
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union {
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struct path path;
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struct file *file;
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struct inode *inode;
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};
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/* when calling fsnotify tell it if the data is a path or inode */
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#define FSNOTIFY_EVENT_NONE 0
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#define FSNOTIFY_EVENT_PATH 1
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#define FSNOTIFY_EVENT_FILE 1
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#define FSNOTIFY_EVENT_INODE 2
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int data_type; /* which of the above union we have */
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atomic_t refcnt; /* how many groups still are using/need to send this event */
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@ -311,7 +311,7 @@ struct fsnotify_mark {
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/* main fsnotify call to send events */
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extern int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
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const unsigned char *name, u32 cookie);
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extern void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask);
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extern void __fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask);
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extern void __fsnotify_inode_delete(struct inode *inode);
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extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt);
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extern u32 fsnotify_get_cookie(void);
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@ -444,7 +444,7 @@ static inline int fsnotify(struct inode *to_tell, __u32 mask, void *data, int da
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return 0;
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}
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static inline void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
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static inline void __fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask)
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{}
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static inline void __fsnotify_inode_delete(struct inode *inode)
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@ -545,8 +545,8 @@ static int audit_watch_handle_event(struct fsnotify_group *group, struct fsnotif
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return 0;
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switch (event->data_type) {
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case (FSNOTIFY_EVENT_PATH):
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inode = event->path.dentry->d_inode;
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case (FSNOTIFY_EVENT_FILE):
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inode = event->file->f_path.dentry->d_inode;
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break;
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case (FSNOTIFY_EVENT_INODE):
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inode = event->inode;
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