diff options
Diffstat (limited to 'include/linux/fsnotify.h')
-rw-r--r-- | include/linux/fsnotify.h | 277 |
1 files changed, 164 insertions, 113 deletions
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index a2d5d175d3c1..bb8467cd11ae 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -18,59 +18,101 @@ #include <linux/bug.h> /* - * Notify this @dir inode about a change in the directory entry @dentry. + * Notify this @dir inode about a change in a child directory entry. + * The directory entry may have turned positive or negative or its inode may + * have changed (i.e. renamed over). * * Unlike fsnotify_parent(), the event will be reported regardless of the - * FS_EVENT_ON_CHILD mask on the parent inode. + * FS_EVENT_ON_CHILD mask on the parent inode and will not be reported if only + * the child is interested and not the parent. */ -static inline int fsnotify_dirent(struct inode *dir, struct dentry *dentry, - __u32 mask) +static inline int fsnotify_name(__u32 mask, const void *data, int data_type, + struct inode *dir, const struct qstr *name, + u32 cookie) { - return fsnotify(dir, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE, - &dentry->d_name, 0); + if (atomic_long_read(&dir->i_sb->s_fsnotify_connectors) == 0) + return 0; + + return fsnotify(mask, data, data_type, dir, name, NULL, cookie); +} + +static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry, + __u32 mask) +{ + fsnotify_name(mask, dentry, FSNOTIFY_EVENT_DENTRY, dir, &dentry->d_name, 0); +} + +static inline void fsnotify_inode(struct inode *inode, __u32 mask) +{ + if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0) + return; + + if (S_ISDIR(inode->i_mode)) + mask |= FS_ISDIR; + + fsnotify(mask, inode, FSNOTIFY_EVENT_INODE, NULL, NULL, inode, 0); } /* Notify this dentry's parent about a child's events. */ -static inline int fsnotify_parent(const struct path *path, - struct dentry *dentry, __u32 mask) +static inline int fsnotify_parent(struct dentry *dentry, __u32 mask, + const void *data, int data_type) { - if (!dentry) - dentry = path->dentry; + struct inode *inode = d_inode(dentry); - return __fsnotify_parent(path, dentry, mask); + if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0) + return 0; + + if (S_ISDIR(inode->i_mode)) { + mask |= FS_ISDIR; + + /* sb/mount marks are not interested in name of directory */ + if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED)) + goto notify_child; + } + + /* disconnected dentry cannot notify parent */ + if (IS_ROOT(dentry)) + goto notify_child; + + return __fsnotify_parent(dentry, mask, data, data_type); + +notify_child: + return fsnotify(mask, data, data_type, NULL, NULL, inode, 0); } /* - * Simple wrapper to consolidate calls fsnotify_parent()/fsnotify() when - * an event is on a path. + * Simple wrappers to consolidate calls to fsnotify_parent() when an event + * is on a file/dentry. */ -static inline int fsnotify_path(struct inode *inode, const struct path *path, - __u32 mask) +static inline void fsnotify_dentry(struct dentry *dentry, __u32 mask) +{ + fsnotify_parent(dentry, mask, dentry, FSNOTIFY_EVENT_DENTRY); +} + +static inline int fsnotify_file(struct file *file, __u32 mask) { - int ret = fsnotify_parent(path, NULL, mask); + const struct path *path = &file->f_path; + + if (file->f_mode & FMODE_NONOTIFY) + return 0; - if (ret) - return ret; - return fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); + return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH); } /* Simple call site for access decisions */ static inline int fsnotify_perm(struct file *file, int mask) { int ret; - const struct path *path = &file->f_path; - struct inode *inode = file_inode(file); __u32 fsnotify_mask = 0; - if (file->f_mode & FMODE_NONOTIFY) - return 0; if (!(mask & (MAY_READ | MAY_OPEN))) return 0; + if (mask & MAY_OPEN) { fsnotify_mask = FS_OPEN_PERM; if (file->f_flags & __FMODE_EXEC) { - ret = fsnotify_path(inode, path, FS_OPEN_EXEC_PERM); + ret = fsnotify_file(file, FS_OPEN_EXEC_PERM); if (ret) return ret; @@ -79,10 +121,7 @@ static inline int fsnotify_perm(struct file *file, int mask) fsnotify_mask = FS_ACCESS_PERM; } - if (S_ISDIR(inode->i_mode)) - fsnotify_mask |= FS_ISDIR; - - return fsnotify_path(inode, path, fsnotify_mask); + return fsnotify_file(file, fsnotify_mask); } /* @@ -90,12 +129,7 @@ static inline int fsnotify_perm(struct file *file, int mask) */ static inline void fsnotify_link_count(struct inode *inode) { - __u32 mask = FS_ATTRIB; - - if (S_ISDIR(inode->i_mode)) - mask |= FS_ISDIR; - - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); + fsnotify_inode(inode, FS_ATTRIB); } /* @@ -110,28 +144,27 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, u32 fs_cookie = fsnotify_get_cookie(); __u32 old_dir_mask = FS_MOVED_FROM; __u32 new_dir_mask = FS_MOVED_TO; - __u32 mask = FS_MOVE_SELF; + __u32 rename_mask = FS_RENAME; const struct qstr *new_name = &moved->d_name; - if (old_dir == new_dir) - old_dir_mask |= FS_DN_RENAME; - if (isdir) { old_dir_mask |= FS_ISDIR; new_dir_mask |= FS_ISDIR; - mask |= FS_ISDIR; + rename_mask |= FS_ISDIR; } - fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name, - fs_cookie); - fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name, - fs_cookie); + /* Event with information about both old and new parent+name */ + fsnotify_name(rename_mask, moved, FSNOTIFY_EVENT_DENTRY, + old_dir, old_name, 0); + + fsnotify_name(old_dir_mask, source, FSNOTIFY_EVENT_INODE, + old_dir, old_name, fs_cookie); + fsnotify_name(new_dir_mask, source, FSNOTIFY_EVENT_INODE, + new_dir, new_name, fs_cookie); if (target) fsnotify_link_count(target); - - if (source) - fsnotify(source, mask, source, FSNOTIFY_EVENT_INODE, NULL, 0); + fsnotify_inode(source, FS_MOVE_SELF); audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE); } @@ -156,36 +189,76 @@ static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt) */ static inline void fsnotify_inoderemove(struct inode *inode) { - __u32 mask = FS_DELETE_SELF; - - if (S_ISDIR(inode->i_mode)) - mask |= FS_ISDIR; - - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); + fsnotify_inode(inode, FS_DELETE_SELF); __fsnotify_inode_delete(inode); } /* * fsnotify_create - 'name' was linked in + * + * Caller must make sure that dentry->d_name is stable. + * Note: some filesystems (e.g. kernfs) leave @dentry negative and instantiate + * ->d_inode later */ -static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) +static inline void fsnotify_create(struct inode *dir, struct dentry *dentry) { - audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE); + audit_inode_child(dir, dentry, AUDIT_TYPE_CHILD_CREATE); - fsnotify_dirent(inode, dentry, FS_CREATE); + fsnotify_dirent(dir, dentry, FS_CREATE); } /* * fsnotify_link - new hardlink in 'inode' directory + * + * Caller must make sure that new_dentry->d_name is stable. * Note: We have to pass also the linked inode ptr as some filesystems leave * new_dentry->d_inode NULL and instantiate inode pointer later */ -static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry) +static inline void fsnotify_link(struct inode *dir, struct inode *inode, + struct dentry *new_dentry) { fsnotify_link_count(inode); audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE); - fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, &new_dentry->d_name, 0); + fsnotify_name(FS_CREATE, inode, FSNOTIFY_EVENT_INODE, + dir, &new_dentry->d_name, 0); +} + +/* + * fsnotify_delete - @dentry was unlinked and unhashed + * + * Caller must make sure that dentry->d_name is stable. + * + * Note: unlike fsnotify_unlink(), we have to pass also the unlinked inode + * as this may be called after d_delete() and old_dentry may be negative. + */ +static inline void fsnotify_delete(struct inode *dir, struct inode *inode, + struct dentry *dentry) +{ + __u32 mask = FS_DELETE; + + if (S_ISDIR(inode->i_mode)) + mask |= FS_ISDIR; + + fsnotify_name(mask, inode, FSNOTIFY_EVENT_INODE, dir, &dentry->d_name, + 0); +} + +/** + * d_delete_notify - delete a dentry and call fsnotify_delete() + * @dentry: The dentry to delete + * + * This helper is used to guaranty that the unlinked inode cannot be found + * by lookup of this name after fsnotify_delete() event has been delivered. + */ +static inline void d_delete_notify(struct inode *dir, struct dentry *dentry) +{ + struct inode *inode = d_inode(dentry); + + ihold(inode); + d_delete(dentry); + fsnotify_delete(dir, inode, dentry); + iput(inode); } /* @@ -195,20 +268,24 @@ static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct */ static inline void fsnotify_unlink(struct inode *dir, struct dentry *dentry) { - /* Expected to be called before d_delete() */ - WARN_ON_ONCE(d_is_negative(dentry)); + if (WARN_ON_ONCE(d_is_negative(dentry))) + return; - fsnotify_dirent(dir, dentry, FS_DELETE); + fsnotify_delete(dir, d_inode(dentry), dentry); } /* * fsnotify_mkdir - directory 'name' was created + * + * Caller must make sure that dentry->d_name is stable. + * Note: some filesystems (e.g. kernfs) leave @dentry negative and instantiate + * ->d_inode later */ -static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) +static inline void fsnotify_mkdir(struct inode *dir, struct dentry *dentry) { - audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE); + audit_inode_child(dir, dentry, AUDIT_TYPE_CHILD_CREATE); - fsnotify_dirent(inode, dentry, FS_CREATE | FS_ISDIR); + fsnotify_dirent(dir, dentry, FS_CREATE | FS_ISDIR); } /* @@ -218,10 +295,10 @@ static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) */ static inline void fsnotify_rmdir(struct inode *dir, struct dentry *dentry) { - /* Expected to be called before d_delete() */ - WARN_ON_ONCE(d_is_negative(dentry)); + if (WARN_ON_ONCE(d_is_negative(dentry))) + return; - fsnotify_dirent(dir, dentry, FS_DELETE | FS_ISDIR); + fsnotify_delete(dir, d_inode(dentry), dentry); } /* @@ -229,15 +306,7 @@ static inline void fsnotify_rmdir(struct inode *dir, struct dentry *dentry) */ static inline void fsnotify_access(struct file *file) { - const struct path *path = &file->f_path; - struct inode *inode = file_inode(file); - __u32 mask = FS_ACCESS; - - if (S_ISDIR(inode->i_mode)) - mask |= FS_ISDIR; - - if (!(file->f_mode & FMODE_NONOTIFY)) - fsnotify_path(inode, path, mask); + fsnotify_file(file, FS_ACCESS); } /* @@ -245,15 +314,7 @@ static inline void fsnotify_access(struct file *file) */ static inline void fsnotify_modify(struct file *file) { - const struct path *path = &file->f_path; - struct inode *inode = file_inode(file); - __u32 mask = FS_MODIFY; - - if (S_ISDIR(inode->i_mode)) - mask |= FS_ISDIR; - - if (!(file->f_mode & FMODE_NONOTIFY)) - fsnotify_path(inode, path, mask); + fsnotify_file(file, FS_MODIFY); } /* @@ -261,16 +322,12 @@ static inline void fsnotify_modify(struct file *file) */ static inline void fsnotify_open(struct file *file) { - const struct path *path = &file->f_path; - struct inode *inode = file_inode(file); __u32 mask = FS_OPEN; - if (S_ISDIR(inode->i_mode)) - mask |= FS_ISDIR; if (file->f_flags & __FMODE_EXEC) mask |= FS_OPEN_EXEC; - fsnotify_path(inode, path, mask); + fsnotify_file(file, mask); } /* @@ -278,16 +335,10 @@ static inline void fsnotify_open(struct file *file) */ static inline void fsnotify_close(struct file *file) { - const struct path *path = &file->f_path; - struct inode *inode = file_inode(file); - fmode_t mode = file->f_mode; - __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE; - - if (S_ISDIR(inode->i_mode)) - mask |= FS_ISDIR; + __u32 mask = (file->f_mode & FMODE_WRITE) ? FS_CLOSE_WRITE : + FS_CLOSE_NOWRITE; - if (!(file->f_mode & FMODE_NONOTIFY)) - fsnotify_path(inode, path, mask); + fsnotify_file(file, mask); } /* @@ -295,14 +346,7 @@ static inline void fsnotify_close(struct file *file) */ static inline void fsnotify_xattr(struct dentry *dentry) { - struct inode *inode = dentry->d_inode; - __u32 mask = FS_ATTRIB; - - if (S_ISDIR(inode->i_mode)) - mask |= FS_ISDIR; - - fsnotify_parent(NULL, dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); + fsnotify_dentry(dentry, FS_ATTRIB); } /* @@ -311,7 +355,6 @@ static inline void fsnotify_xattr(struct dentry *dentry) */ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) { - struct inode *inode = dentry->d_inode; __u32 mask = 0; if (ia_valid & ATTR_UID) @@ -332,13 +375,21 @@ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) if (ia_valid & ATTR_MODE) mask |= FS_ATTRIB; - if (mask) { - if (S_ISDIR(inode->i_mode)) - mask |= FS_ISDIR; + if (mask) + fsnotify_dentry(dentry, mask); +} - fsnotify_parent(NULL, dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); - } +static inline int fsnotify_sb_error(struct super_block *sb, struct inode *inode, + int error) +{ + struct fs_error_report report = { + .error = error, + .inode = inode, + .sb = sb, + }; + + return fsnotify(FS_ERROR, &report, FSNOTIFY_EVENT_ERROR, + NULL, NULL, NULL, 0); } #endif /* _LINUX_FS_NOTIFY_H */ |