diff options
Diffstat (limited to 'include/linux/fsnotify.h')
| -rw-r--r-- | include/linux/fsnotify.h | 175 |
1 files changed, 153 insertions, 22 deletions
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index bb8467cd11ae..28a9cb13fbfa 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -17,6 +17,25 @@ #include <linux/slab.h> #include <linux/bug.h> +/* Are there any inode/mount/sb objects watched with priority prio or above? */ +static inline bool fsnotify_sb_has_priority_watchers(struct super_block *sb, + int prio) +{ + struct fsnotify_sb_info *sbinfo = fsnotify_sb_info(sb); + + /* Were any marks ever added to any object on this sb? */ + if (!sbinfo) + return false; + + return atomic_long_read(&sbinfo->watched_objects[prio]); +} + +/* Are there any inode/mount/sb objects that are being watched at all? */ +static inline bool fsnotify_sb_has_watchers(struct super_block *sb) +{ + return fsnotify_sb_has_priority_watchers(sb, 0); +} + /* * 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 @@ -30,7 +49,7 @@ static inline int fsnotify_name(__u32 mask, const void *data, int data_type, struct inode *dir, const struct qstr *name, u32 cookie) { - if (atomic_long_read(&dir->i_sb->s_fsnotify_connectors) == 0) + if (!fsnotify_sb_has_watchers(dir->i_sb)) return 0; return fsnotify(mask, data, data_type, dir, name, NULL, cookie); @@ -44,7 +63,7 @@ static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry, static inline void fsnotify_inode(struct inode *inode, __u32 mask) { - if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0) + if (!fsnotify_sb_has_watchers(inode->i_sb)) return; if (S_ISDIR(inode->i_mode)) @@ -59,7 +78,7 @@ static inline int fsnotify_parent(struct dentry *dentry, __u32 mask, { struct inode *inode = d_inode(dentry); - if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0) + if (!fsnotify_sb_has_watchers(inode->i_sb)) return 0; if (S_ISDIR(inode->i_mode)) { @@ -89,40 +108,132 @@ static inline void fsnotify_dentry(struct dentry *dentry, __u32 mask) fsnotify_parent(dentry, mask, dentry, FSNOTIFY_EVENT_DENTRY); } +static inline int fsnotify_path(const struct path *path, __u32 mask) +{ + return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH); +} + static inline int fsnotify_file(struct file *file, __u32 mask) { - const struct path *path = &file->f_path; + /* + * FMODE_NONOTIFY are fds generated by fanotify itself which should not + * generate new events. We also don't want to generate events for + * FMODE_PATH fds (involves open & close events) as they are just + * handle creation / destruction events and not "real" file events. + */ + if (FMODE_FSNOTIFY_NONE(file->f_mode)) + return 0; + + return fsnotify_path(&file->f_path, mask); +} + +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + +int fsnotify_open_perm_and_set_mode(struct file *file); - if (file->f_mode & FMODE_NONOTIFY) +/* + * fsnotify_file_area_perm - permission hook before access to file range + */ +static inline int fsnotify_file_area_perm(struct file *file, int perm_mask, + const loff_t *ppos, size_t count) +{ + /* + * filesystem may be modified in the context of permission events + * (e.g. by HSM filling a file on access), so sb freeze protection + * must not be held. + */ + lockdep_assert_once(file_write_not_started(file)); + + if (!(perm_mask & (MAY_READ | MAY_WRITE | MAY_ACCESS))) return 0; - return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH); + /* + * read()/write() and other types of access generate pre-content events. + */ + if (unlikely(FMODE_FSNOTIFY_HSM(file->f_mode))) { + int ret = fsnotify_pre_content(&file->f_path, ppos, count); + + if (ret) + return ret; + } + + if (!(perm_mask & MAY_READ) || + likely(!FMODE_FSNOTIFY_ACCESS_PERM(file->f_mode))) + return 0; + + /* + * read() also generates the legacy FS_ACCESS_PERM event, so content + * scanners can inspect the content filled by pre-content event. + */ + return fsnotify_path(&file->f_path, FS_ACCESS_PERM); } -/* Simple call site for access decisions */ -static inline int fsnotify_perm(struct file *file, int mask) +/* + * fsnotify_mmap_perm - permission hook before mmap of file range + */ +static inline int fsnotify_mmap_perm(struct file *file, int prot, + const loff_t off, size_t len) { - int ret; - __u32 fsnotify_mask = 0; + /* + * mmap() generates only pre-content events. + */ + if (!file || likely(!FMODE_FSNOTIFY_HSM(file->f_mode))) + return 0; - if (!(mask & (MAY_READ | MAY_OPEN))) + return fsnotify_pre_content(&file->f_path, &off, len); +} + +/* + * fsnotify_truncate_perm - permission hook before file truncate + */ +static inline int fsnotify_truncate_perm(const struct path *path, loff_t length) +{ + struct inode *inode = d_inode(path->dentry); + + if (!(inode->i_sb->s_iflags & SB_I_ALLOW_HSM) || + !fsnotify_sb_has_priority_watchers(inode->i_sb, + FSNOTIFY_PRIO_PRE_CONTENT)) return 0; - if (mask & MAY_OPEN) { - fsnotify_mask = FS_OPEN_PERM; + return fsnotify_pre_content(path, &length, 0); +} - if (file->f_flags & __FMODE_EXEC) { - ret = fsnotify_file(file, FS_OPEN_EXEC_PERM); +/* + * fsnotify_file_perm - permission hook before file access (unknown range) + */ +static inline int fsnotify_file_perm(struct file *file, int perm_mask) +{ + return fsnotify_file_area_perm(file, perm_mask, NULL, 0); +} - if (ret) - return ret; - } - } else if (mask & MAY_READ) { - fsnotify_mask = FS_ACCESS_PERM; - } +#else +static inline int fsnotify_open_perm_and_set_mode(struct file *file) +{ + return 0; +} + +static inline int fsnotify_file_area_perm(struct file *file, int perm_mask, + const loff_t *ppos, size_t count) +{ + return 0; +} + +static inline int fsnotify_mmap_perm(struct file *file, int prot, + const loff_t off, size_t len) +{ + return 0; +} - return fsnotify_file(file, fsnotify_mask); +static inline int fsnotify_truncate_perm(const struct path *path, loff_t length) +{ + return 0; +} + +static inline int fsnotify_file_perm(struct file *file, int perm_mask) +{ + return 0; } +#endif /* * fsnotify_link_count - inode's link count changed @@ -184,6 +295,11 @@ static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt) __fsnotify_vfsmount_delete(mnt); } +static inline void fsnotify_mntns_delete(struct mnt_namespace *mntns) +{ + __fsnotify_mntns_delete(mntns); +} + /* * fsnotify_inoderemove - an inode is going away */ @@ -392,4 +508,19 @@ static inline int fsnotify_sb_error(struct super_block *sb, struct inode *inode, NULL, NULL, NULL, 0); } +static inline void fsnotify_mnt_attach(struct mnt_namespace *ns, struct vfsmount *mnt) +{ + fsnotify_mnt(FS_MNT_ATTACH, ns, mnt); +} + +static inline void fsnotify_mnt_detach(struct mnt_namespace *ns, struct vfsmount *mnt) +{ + fsnotify_mnt(FS_MNT_DETACH, ns, mnt); +} + +static inline void fsnotify_mnt_move(struct mnt_namespace *ns, struct vfsmount *mnt) +{ + fsnotify_mnt(FS_MNT_MOVE, ns, mnt); +} + #endif /* _LINUX_FS_NOTIFY_H */ |