diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 5778d1347b35..5435a40f82be 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -17,6 +17,59 @@ #include "fanotify.h" +static bool fanotify_path_equal(struct path *p1, struct path *p2) +{ + return p1->mnt == p2->mnt && p1->dentry == p2->dentry; +} + +static inline bool fanotify_fsid_equal(__kernel_fsid_t *fsid1, + __kernel_fsid_t *fsid2) +{ + return fsid1->val[0] == fsid2->val[0] && fsid1->val[1] == fsid2->val[1]; +} + +static bool fanotify_fh_equal(struct fanotify_fh *fh1, + struct fanotify_fh *fh2) +{ + if (fh1->type != fh2->type || fh1->len != fh2->len) + return false; + + /* Do not merge events if we failed to encode fh */ + if (fh1->type == FILEID_INVALID) + return false; + + return !fh1->len || + !memcmp(fanotify_fh_buf(fh1), fanotify_fh_buf(fh2), fh1->len); +} + +static bool fanotify_fid_event_equal(struct fanotify_fid_event *ffe1, + struct fanotify_fid_event *ffe2) +{ + /* Do not merge fid events without object fh */ + if (!ffe1->object_fh.len) + return false; + + return fanotify_fsid_equal(&ffe1->fsid, &ffe2->fsid) && + fanotify_fh_equal(&ffe1->object_fh, &ffe2->object_fh); +} + +static bool fanotify_name_event_equal(struct fanotify_name_event *fne1, + struct fanotify_name_event *fne2) +{ + /* + * Do not merge name events without dir fh. + * FAN_DIR_MODIFY does not encode object fh, so it may be empty. + */ + if (!fne1->dir_fh.len) + return false; + + if (fne1->name_len != fne2->name_len || + !fanotify_fh_equal(&fne1->dir_fh, &fne2->dir_fh)) + return false; + + return !memcmp(fne1->name, fne2->name, fne1->name_len); +} + static bool should_merge(struct fsnotify_event *old_fsn, struct fsnotify_event *new_fsn) { @@ -26,14 +79,15 @@ static bool should_merge(struct fsnotify_event *old_fsn, old = FANOTIFY_E(old_fsn); new = FANOTIFY_E(new_fsn); - if (old_fsn->inode != new_fsn->inode || old->pid != new->pid || - old->fh_type != new->fh_type || old->fh_len != new->fh_len) + if (old_fsn->objectid != new_fsn->objectid || + old->type != new->type || old->pid != new->pid) return false; - if (fanotify_event_has_path(old)) { - return old->path.mnt == new->path.mnt && - old->path.dentry == new->path.dentry; - } else if (fanotify_event_has_fid(old)) { + switch (old->type) { + case FANOTIFY_EVENT_TYPE_PATH: + return fanotify_path_equal(fanotify_event_path(old), + fanotify_event_path(new)); + case FANOTIFY_EVENT_TYPE_FID: /* * We want to merge many dirent events in the same dir (i.e. * creates/unlinks/renames), but we do not want to merge dirent @@ -42,11 +96,18 @@ static bool should_merge(struct fsnotify_event *old_fsn, * mask FAN_CREATE|FAN_DELETE|FAN_ONDIR if it describes mkdir+ * unlink pair or rmdir+create pair of events. */ - return (old->mask & FS_ISDIR) == (new->mask & FS_ISDIR) && - fanotify_fid_equal(&old->fid, &new->fid, old->fh_len); + if ((old->mask & FS_ISDIR) != (new->mask & FS_ISDIR)) + return false; + + return fanotify_fid_event_equal(FANOTIFY_FE(old), + FANOTIFY_FE(new)); + case FANOTIFY_EVENT_TYPE_FID_NAME: + return fanotify_name_event_equal(FANOTIFY_NE(old), + FANOTIFY_NE(new)); + default: + WARN_ON_ONCE(1); } - /* Do not merge events if we failed to encode fid */ return false; } @@ -151,7 +212,7 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, { __u32 marks_mask = 0, marks_ignored_mask = 0; __u32 test_mask, user_mask = FANOTIFY_OUTGOING_EVENTS; - const struct path *path = data; + const struct path *path = fsnotify_data_path(data, data_type); struct fsnotify_mark *mark; int type; @@ -160,7 +221,7 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, if (!FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { /* Do we have path to open a file descriptor? */ - if (data_type != FSNOTIFY_EVENT_PATH) + if (!path) return 0; /* Path type events are only relevant for files and dirs */ if (!d_is_reg(path->dentry) && !d_can_lookup(path->dentry)) @@ -171,6 +232,13 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, if (!fsnotify_iter_should_report_type(iter_info, type)) continue; mark = iter_info->marks[type]; + /* + * If the event is on dir and this mark doesn't care about + * events on dir, don't send it! + */ + if (event_mask & FS_ISDIR && !(mark->mask & FS_ISDIR)) + continue; + /* * If the event is for a child and this mark doesn't care about * events on a child, don't send it! @@ -187,9 +255,9 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, test_mask = event_mask & marks_mask & ~marks_ignored_mask; /* - * dirent modification events (create/delete/move) do not carry the - * child entry name/inode information. Instead, we report FAN_ONDIR - * for mkdir/rmdir so user can differentiate them from creat/unlink. + * For dirent modification events (create/delete/move) that do not carry + * the child entry name information, we report FAN_ONDIR for mkdir/rmdir + * so user can differentiate them from creat/unlink. * * For backward compatibility and consistency, do not report FAN_ONDIR * to user in legacy fanotify mode (reporting fd) and report FAN_ONDIR @@ -203,22 +271,20 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, user_mask &= ~FAN_ONDIR; } - if (event_mask & FS_ISDIR && - !(marks_mask & FS_ISDIR & ~marks_ignored_mask)) - return 0; - return test_mask & user_mask; } -static int fanotify_encode_fid(struct fanotify_event *event, - struct inode *inode, gfp_t gfp, - __kernel_fsid_t *fsid) +static void fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode, + gfp_t gfp) { - struct fanotify_fid *fid = &event->fid; - int dwords, bytes = 0; - int err, type; + int dwords, type, bytes = 0; + char *ext_buf = NULL; + void *buf = fh->buf; + int err; + + if (!inode) + goto out; - fid->ext_fh = NULL; dwords = 0; err = -ENOENT; type = exportfs_encode_inode_fh(inode, NULL, &dwords, NULL); @@ -229,31 +295,33 @@ static int fanotify_encode_fid(struct fanotify_event *event, if (bytes > FANOTIFY_INLINE_FH_LEN) { /* Treat failure to allocate fh as failure to allocate event */ err = -ENOMEM; - fid->ext_fh = kmalloc(bytes, gfp); - if (!fid->ext_fh) + ext_buf = kmalloc(bytes, gfp); + if (!ext_buf) goto out_err; + + *fanotify_fh_ext_buf_ptr(fh) = ext_buf; + buf = ext_buf; } - type = exportfs_encode_inode_fh(inode, fanotify_fid_fh(fid, bytes), - &dwords, NULL); + type = exportfs_encode_inode_fh(inode, buf, &dwords, NULL); err = -EINVAL; if (!type || type == FILEID_INVALID || bytes != dwords << 2) goto out_err; - fid->fsid = *fsid; - event->fh_len = bytes; + fh->type = type; + fh->len = bytes; - return type; + return; out_err: - pr_warn_ratelimited("fanotify: failed to encode fid (fsid=%x.%x, " - "type=%d, bytes=%d, err=%i)\n", - fsid->val[0], fsid->val[1], type, bytes, err); - kfree(fid->ext_fh); - fid->ext_fh = NULL; - event->fh_len = 0; - - return FILEID_INVALID; + pr_warn_ratelimited("fanotify: failed to encode fid (type=%d, len=%d, err=%i)\n", + type, bytes, err); + kfree(ext_buf); + *fanotify_fh_ext_buf_ptr(fh) = NULL; +out: + /* Report the event without a file identifier on encode error */ + fh->type = FILEID_INVALID; + fh->len = 0; } /* @@ -269,21 +337,22 @@ static struct inode *fanotify_fid_inode(struct inode *to_tell, u32 event_mask, { if (event_mask & ALL_FSNOTIFY_DIRENT_EVENTS) return to_tell; - else if (data_type == FSNOTIFY_EVENT_INODE) - return (struct inode *)data; - else if (data_type == FSNOTIFY_EVENT_PATH) - return d_inode(((struct path *)data)->dentry); - return NULL; + + return (struct inode *)fsnotify_data_inode(data, data_type); } struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, struct inode *inode, u32 mask, const void *data, int data_type, + const struct qstr *file_name, __kernel_fsid_t *fsid) { struct fanotify_event *event = NULL; + struct fanotify_fid_event *ffe = NULL; + struct fanotify_name_event *fne = NULL; gfp_t gfp = GFP_KERNEL_ACCOUNT; struct inode *id = fanotify_fid_inode(inode, mask, data, data_type); + const struct path *path = fsnotify_data_path(data, data_type); /* * For queues with unlimited length lost events are not expected and @@ -305,33 +374,81 @@ struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp); if (!pevent) goto out; + event = &pevent->fae; + event->type = FANOTIFY_EVENT_TYPE_PATH_PERM; pevent->response = 0; pevent->state = FAN_EVENT_INIT; goto init; } - event = kmem_cache_alloc(fanotify_event_cachep, gfp); - if (!event) - goto out; -init: __maybe_unused - fsnotify_init_event(&event->fse, inode); + + /* + * For FAN_DIR_MODIFY event, we report the fid of the directory and + * the name of the modified entry. + * Allocate an fanotify_name_event struct and copy the name. + */ + if (mask & FAN_DIR_MODIFY && !(WARN_ON_ONCE(!file_name))) { + fne = kmalloc(sizeof(*fne) + file_name->len + 1, gfp); + if (!fne) + goto out; + + event = &fne->fae; + event->type = FANOTIFY_EVENT_TYPE_FID_NAME; + fne->name_len = file_name->len; + strcpy(fne->name, file_name->name); + goto init; + } + + if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { + ffe = kmem_cache_alloc(fanotify_fid_event_cachep, gfp); + if (!ffe) + goto out; + + event = &ffe->fae; + event->type = FANOTIFY_EVENT_TYPE_FID; + } else { + struct fanotify_path_event *pevent; + + pevent = kmem_cache_alloc(fanotify_path_event_cachep, gfp); + if (!pevent) + goto out; + + event = &pevent->fae; + event->type = FANOTIFY_EVENT_TYPE_PATH; + } + +init: + /* + * Use the victim inode instead of the watching inode as the id for + * event queue, so event reported on parent is merged with event + * reported on child when both directory and child watches exist. + */ + fsnotify_init_event(&event->fse, (unsigned long)id); event->mask = mask; if (FAN_GROUP_FLAG(group, FAN_REPORT_TID)) event->pid = get_pid(task_pid(current)); else event->pid = get_pid(task_tgid(current)); - event->fh_len = 0; - if (id && FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { - /* Report the event without a file identifier on encode error */ - event->fh_type = fanotify_encode_fid(event, id, gfp, fsid); - } else if (data_type == FSNOTIFY_EVENT_PATH) { - event->fh_type = FILEID_ROOT; - event->path = *((struct path *)data); - path_get(&event->path); - } else { - event->fh_type = FILEID_INVALID; - event->path.mnt = NULL; - event->path.dentry = NULL; + + if (fsid && fanotify_event_fsid(event)) + *fanotify_event_fsid(event) = *fsid; + + if (fanotify_event_object_fh(event)) + fanotify_encode_fh(fanotify_event_object_fh(event), id, gfp); + + if (fanotify_event_dir_fh(event)) + fanotify_encode_fh(fanotify_event_dir_fh(event), id, gfp); + + if (fanotify_event_has_path(event)) { + struct path *p = fanotify_event_path(event); + + if (path) { + *p = *path; + path_get(path); + } else { + p->mnt = NULL; + p->dentry = NULL; + } } out: memalloc_unuse_memcg(); @@ -392,6 +509,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, BUILD_BUG_ON(FAN_MOVED_FROM != FS_MOVED_FROM); BUILD_BUG_ON(FAN_CREATE != FS_CREATE); BUILD_BUG_ON(FAN_DELETE != FS_DELETE); + BUILD_BUG_ON(FAN_DIR_MODIFY != FS_DIR_MODIFY); BUILD_BUG_ON(FAN_DELETE_SELF != FS_DELETE_SELF); BUILD_BUG_ON(FAN_MOVE_SELF != FS_MOVE_SELF); BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD); @@ -402,7 +520,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, BUILD_BUG_ON(FAN_OPEN_EXEC != FS_OPEN_EXEC); BUILD_BUG_ON(FAN_OPEN_EXEC_PERM != FS_OPEN_EXEC_PERM); - BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 19); + BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 20); mask = fanotify_group_event_mask(group, iter_info, mask, data, data_type); @@ -429,7 +547,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, } event = fanotify_alloc_event(group, inode, mask, data, data_type, - &fsid); + file_name, &fsid); ret = -ENOMEM; if (unlikely(!event)) { /* @@ -451,7 +569,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, ret = 0; } else if (fanotify_is_perm_event(mask)) { - ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event), + ret = fanotify_get_response(group, FANOTIFY_PERM(event), iter_info); } finish: @@ -470,22 +588,58 @@ static void fanotify_free_group_priv(struct fsnotify_group *group) free_uid(user); } +static void fanotify_free_path_event(struct fanotify_event *event) +{ + path_put(fanotify_event_path(event)); + kmem_cache_free(fanotify_path_event_cachep, FANOTIFY_PE(event)); +} + +static void fanotify_free_perm_event(struct fanotify_event *event) +{ + path_put(fanotify_event_path(event)); + kmem_cache_free(fanotify_perm_event_cachep, FANOTIFY_PERM(event)); +} + +static void fanotify_free_fid_event(struct fanotify_event *event) +{ + struct fanotify_fid_event *ffe = FANOTIFY_FE(event); + + if (fanotify_fh_has_ext_buf(&ffe->object_fh)) + kfree(fanotify_fh_ext_buf(&ffe->object_fh)); + kmem_cache_free(fanotify_fid_event_cachep, ffe); +} + +static void fanotify_free_name_event(struct fanotify_event *event) +{ + struct fanotify_name_event *fne = FANOTIFY_NE(event); + + if (fanotify_fh_has_ext_buf(&fne->dir_fh)) + kfree(fanotify_fh_ext_buf(&fne->dir_fh)); + kfree(fne); +} + static void fanotify_free_event(struct fsnotify_event *fsn_event) { struct fanotify_event *event; event = FANOTIFY_E(fsn_event); - if (fanotify_event_has_path(event)) - path_put(&event->path); - else if (fanotify_event_has_ext_fh(event)) - kfree(event->fid.ext_fh); put_pid(event->pid); - if (fanotify_is_perm_event(event->mask)) { - kmem_cache_free(fanotify_perm_event_cachep, - FANOTIFY_PE(fsn_event)); - return; + switch (event->type) { + case FANOTIFY_EVENT_TYPE_PATH: + fanotify_free_path_event(event); + break; + case FANOTIFY_EVENT_TYPE_PATH_PERM: + fanotify_free_perm_event(event); + break; + case FANOTIFY_EVENT_TYPE_FID: + fanotify_free_fid_event(event); + break; + case FANOTIFY_EVENT_TYPE_FID_NAME: + fanotify_free_name_event(event); + break; + default: + WARN_ON_ONCE(1); } - kmem_cache_free(fanotify_event_cachep, event); } static void fanotify_free_mark(struct fsnotify_mark *fsn_mark) diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 68b30504284c..35bfbf4a7aac 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -5,7 +5,8 @@ #include extern struct kmem_cache *fanotify_mark_cache; -extern struct kmem_cache *fanotify_event_cachep; +extern struct kmem_cache *fanotify_fid_event_cachep; +extern struct kmem_cache *fanotify_path_event_cachep; extern struct kmem_cache *fanotify_perm_event_cachep; /* Possible states of the permission event */ @@ -18,94 +19,140 @@ enum { /* * 3 dwords are sufficient for most local fs (64bit ino, 32bit generation). - * For 32bit arch, fid increases the size of fanotify_event by 12 bytes and - * fh_* fields increase the size of fanotify_event by another 4 bytes. - * For 64bit arch, fid increases the size of fanotify_fid by 8 bytes and - * fh_* fields are packed in a hole after mask. + * fh buf should be dword aligned. On 64bit arch, the ext_buf pointer is + * stored in either the first or last 2 dwords. */ -#if BITS_PER_LONG == 32 #define FANOTIFY_INLINE_FH_LEN (3 << 2) -#else -#define FANOTIFY_INLINE_FH_LEN (4 << 2) -#endif -struct fanotify_fid { - __kernel_fsid_t fsid; - union { - unsigned char fh[FANOTIFY_INLINE_FH_LEN]; - unsigned char *ext_fh; - }; -}; +struct fanotify_fh { + unsigned char buf[FANOTIFY_INLINE_FH_LEN]; + u8 type; + u8 len; +} __aligned(4); -static inline void *fanotify_fid_fh(struct fanotify_fid *fid, - unsigned int fh_len) +static inline bool fanotify_fh_has_ext_buf(struct fanotify_fh *fh) { - return fh_len <= FANOTIFY_INLINE_FH_LEN ? fid->fh : fid->ext_fh; + return fh->len > FANOTIFY_INLINE_FH_LEN; } -static inline bool fanotify_fid_equal(struct fanotify_fid *fid1, - struct fanotify_fid *fid2, - unsigned int fh_len) +static inline char **fanotify_fh_ext_buf_ptr(struct fanotify_fh *fh) { - return fid1->fsid.val[0] == fid2->fsid.val[0] && - fid1->fsid.val[1] == fid2->fsid.val[1] && - !memcmp(fanotify_fid_fh(fid1, fh_len), - fanotify_fid_fh(fid2, fh_len), fh_len); + BUILD_BUG_ON(__alignof__(char *) - 4 + sizeof(char *) > + FANOTIFY_INLINE_FH_LEN); + return (char **)ALIGN((unsigned long)(fh->buf), __alignof__(char *)); +} + +static inline void *fanotify_fh_ext_buf(struct fanotify_fh *fh) +{ + return *fanotify_fh_ext_buf_ptr(fh); +} + +static inline void *fanotify_fh_buf(struct fanotify_fh *fh) +{ + return fanotify_fh_has_ext_buf(fh) ? fanotify_fh_ext_buf(fh) : fh->buf; } /* - * Structure for normal fanotify events. It gets allocated in + * Common structure for fanotify events. Concrete structs are allocated in * fanotify_handle_event() and freed when the information is retrieved by - * userspace + * userspace. The type of event determines how it was allocated, how it will + * be freed and which concrete struct it may be cast to. */ +enum fanotify_event_type { + FANOTIFY_EVENT_TYPE_FID, /* fixed length */ + FANOTIFY_EVENT_TYPE_FID_NAME, /* variable length */ + FANOTIFY_EVENT_TYPE_PATH, + FANOTIFY_EVENT_TYPE_PATH_PERM, +}; + struct fanotify_event { struct fsnotify_event fse; u32 mask; - /* - * Those fields are outside fanotify_fid to pack fanotify_event nicely - * on 64bit arch and to use fh_type as an indication of whether path - * or fid are used in the union: - * FILEID_ROOT (0) for path, > 0 for fid, FILEID_INVALID for neither. - */ - u8 fh_type; - u8 fh_len; - u16 pad; - union { - /* - * We hold ref to this path so it may be dereferenced at any - * point during this object's lifetime - */ - struct path path; - /* - * With FAN_REPORT_FID, we do not hold any reference on the - * victim object. Instead we store its NFS file handle and its - * filesystem's fsid as a unique identifier. - */ - struct fanotify_fid fid; - }; + enum fanotify_event_type type; struct pid *pid; }; -static inline bool fanotify_event_has_path(struct fanotify_event *event) +struct fanotify_fid_event { + struct fanotify_event fae; + __kernel_fsid_t fsid; + struct fanotify_fh object_fh; +}; + +static inline struct fanotify_fid_event * +FANOTIFY_FE(struct fanotify_event *event) { - return event->fh_type == FILEID_ROOT; + return container_of(event, struct fanotify_fid_event, fae); } -static inline bool fanotify_event_has_fid(struct fanotify_event *event) +struct fanotify_name_event { + struct fanotify_event fae; + __kernel_fsid_t fsid; + struct fanotify_fh dir_fh; + u8 name_len; + char name[0]; +}; + +static inline struct fanotify_name_event * +FANOTIFY_NE(struct fanotify_event *event) { - return event->fh_type != FILEID_ROOT && - event->fh_type != FILEID_INVALID; + return container_of(event, struct fanotify_name_event, fae); } -static inline bool fanotify_event_has_ext_fh(struct fanotify_event *event) +static inline __kernel_fsid_t *fanotify_event_fsid(struct fanotify_event *event) { - return fanotify_event_has_fid(event) && - event->fh_len > FANOTIFY_INLINE_FH_LEN; + if (event->type == FANOTIFY_EVENT_TYPE_FID) + return &FANOTIFY_FE(event)->fsid; + else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME) + return &FANOTIFY_NE(event)->fsid; + else + return NULL; } -static inline void *fanotify_event_fh(struct fanotify_event *event) +static inline struct fanotify_fh *fanotify_event_object_fh( + struct fanotify_event *event) { - return fanotify_fid_fh(&event->fid, event->fh_len); + if (event->type == FANOTIFY_EVENT_TYPE_FID) + return &FANOTIFY_FE(event)->object_fh; + else + return NULL; +} + +static inline struct fanotify_fh *fanotify_event_dir_fh( + struct fanotify_event *event) +{ + if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME) + return &FANOTIFY_NE(event)->dir_fh; + else + return NULL; +} + +static inline int fanotify_event_object_fh_len(struct fanotify_event *event) +{ + struct fanotify_fh *fh = fanotify_event_object_fh(event); + + return fh ? fh->len : 0; +} + +static inline bool fanotify_event_has_name(struct fanotify_event *event) +{ + return event->type == FANOTIFY_EVENT_TYPE_FID_NAME; +} + +static inline int fanotify_event_name_len(struct fanotify_event *event) +{ + return fanotify_event_has_name(event) ? + FANOTIFY_NE(event)->name_len : 0; +} + +struct fanotify_path_event { + struct fanotify_event fae; + struct path path; +}; + +static inline struct fanotify_path_event * +FANOTIFY_PE(struct fanotify_event *event) +{ + return container_of(event, struct fanotify_path_event, fae); } /* @@ -117,15 +164,16 @@ static inline void *fanotify_event_fh(struct fanotify_event *event) */ struct fanotify_perm_event { struct fanotify_event fae; + struct path path; unsigned short response; /* userspace answer to the event */ unsigned short state; /* state of the event */ int fd; /* fd we passed to userspace for this event */ }; static inline struct fanotify_perm_event * -FANOTIFY_PE(struct fsnotify_event *fse) +FANOTIFY_PERM(struct fanotify_event *event) { - return container_of(fse, struct fanotify_perm_event, fae.fse); + return container_of(event, struct fanotify_perm_event, fae); } static inline bool fanotify_is_perm_event(u32 mask) @@ -139,7 +187,24 @@ static inline struct fanotify_event *FANOTIFY_E(struct fsnotify_event *fse) return container_of(fse, struct fanotify_event, fse); } +static inline bool fanotify_event_has_path(struct fanotify_event *event) +{ + return event->type == FANOTIFY_EVENT_TYPE_PATH || + event->type == FANOTIFY_EVENT_TYPE_PATH_PERM; +} + +static inline struct path *fanotify_event_path(struct fanotify_event *event) +{ + if (event->type == FANOTIFY_EVENT_TYPE_PATH) + return &FANOTIFY_PE(event)->path; + else if (event->type == FANOTIFY_EVENT_TYPE_PATH_PERM) + return &FANOTIFY_PERM(event)->path; + else + return NULL; +} + struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, struct inode *inode, u32 mask, const void *data, int data_type, + const struct qstr *file_name, __kernel_fsid_t *fsid); diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 0aa362b88550..42cb794c62ac 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -46,32 +46,53 @@ extern const struct fsnotify_ops fanotify_fsnotify_ops; struct kmem_cache *fanotify_mark_cache __read_mostly; -struct kmem_cache *fanotify_event_cachep __read_mostly; +struct kmem_cache *fanotify_fid_event_cachep __read_mostly; +struct kmem_cache *fanotify_path_event_cachep __read_mostly; struct kmem_cache *fanotify_perm_event_cachep __read_mostly; #define FANOTIFY_EVENT_ALIGN 4 +#define FANOTIFY_INFO_HDR_LEN \ + (sizeof(struct fanotify_event_info_fid) + sizeof(struct file_handle)) + +static int fanotify_fid_info_len(int fh_len, int name_len) +{ + int info_len = fh_len; + + if (name_len) + info_len += name_len + 1; + + return roundup(FANOTIFY_INFO_HDR_LEN + info_len, FANOTIFY_EVENT_ALIGN); +} static int fanotify_event_info_len(struct fanotify_event *event) { - if (!fanotify_event_has_fid(event)) - return 0; + int info_len = 0; + int fh_len = fanotify_event_object_fh_len(event); - return roundup(sizeof(struct fanotify_event_info_fid) + - sizeof(struct file_handle) + event->fh_len, - FANOTIFY_EVENT_ALIGN); + if (fh_len) + info_len += fanotify_fid_info_len(fh_len, 0); + + if (fanotify_event_name_len(event)) { + struct fanotify_name_event *fne = FANOTIFY_NE(event); + + info_len += fanotify_fid_info_len(fne->dir_fh.len, + fne->name_len); + } + + return info_len; } /* - * Get an fsnotify notification event if one exists and is small + * Get an fanotify notification event if one exists and is small * enough to fit in "count". Return an error pointer if the count * is not large enough. When permission event is dequeued, its state is * updated accordingly. */ -static struct fsnotify_event *get_one_event(struct fsnotify_group *group, +static struct fanotify_event *get_one_event(struct fsnotify_group *group, size_t count) { size_t event_size = FAN_EVENT_METADATA_LEN; - struct fsnotify_event *fsn_event = NULL; + struct fanotify_event *event = NULL; pr_debug("%s: group=%p count=%zd\n", __func__, group, count); @@ -85,26 +106,23 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group, } if (event_size > count) { - fsn_event = ERR_PTR(-EINVAL); + event = ERR_PTR(-EINVAL); goto out; } - fsn_event = fsnotify_remove_first_event(group); - if (fanotify_is_perm_event(FANOTIFY_E(fsn_event)->mask)) - FANOTIFY_PE(fsn_event)->state = FAN_EVENT_REPORTED; + event = FANOTIFY_E(fsnotify_remove_first_event(group)); + if (fanotify_is_perm_event(event->mask)) + FANOTIFY_PERM(event)->state = FAN_EVENT_REPORTED; out: spin_unlock(&group->notification_lock); - return fsn_event; + return event; } -static int create_fd(struct fsnotify_group *group, - struct fanotify_event *event, +static int create_fd(struct fsnotify_group *group, struct path *path, struct file **file) { int client_fd; struct file *new_file; - pr_debug("%s: group=%p event=%p\n", __func__, group, event); - client_fd = get_unused_fd_flags(group->fanotify_data.f_flags); if (client_fd < 0) return client_fd; @@ -113,14 +131,9 @@ static int create_fd(struct fsnotify_group *group, * we need a new file handle for the userspace program so it can read even if it was * originally opened O_WRONLY. */ - /* 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 (event->path.dentry && event->path.mnt) - new_file = dentry_open(&event->path, - group->fanotify_data.f_flags | FMODE_NONOTIFY, - current_cred()); - else - new_file = ERR_PTR(-EOVERFLOW); + new_file = dentry_open(path, + group->fanotify_data.f_flags | FMODE_NONOTIFY, + current_cred()); if (IS_ERR(new_file)) { /* * we still send an event even if we can't open the file. this @@ -204,83 +217,111 @@ static int process_access_response(struct fsnotify_group *group, return -ENOENT; } -static int copy_fid_to_user(struct fanotify_event *event, char __user *buf) +static int copy_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, + const char *name, size_t name_len, + char __user *buf, size_t count) { struct fanotify_event_info_fid info = { }; struct file_handle handle = { }; - unsigned char bounce[FANOTIFY_INLINE_FH_LEN], *fh; - size_t fh_len = event->fh_len; - size_t len = fanotify_event_info_len(event); + unsigned char bounce[FANOTIFY_INLINE_FH_LEN], *fh_buf; + size_t fh_len = fh ? fh->len : 0; + size_t info_len = fanotify_fid_info_len(fh_len, name_len); + size_t len = info_len; - if (!len) + pr_debug("%s: fh_len=%zu name_len=%zu, info_len=%zu, count=%zu\n", + __func__, fh_len, name_len, info_len, count); + + if (!fh_len || (name && !name_len)) return 0; - if (WARN_ON_ONCE(len < sizeof(info) + sizeof(handle) + fh_len)) + if (WARN_ON_ONCE(len < sizeof(info) || len > count)) return -EFAULT; - /* Copy event info fid header followed by vaiable sized file handle */ - info.hdr.info_type = FAN_EVENT_INFO_TYPE_FID; + /* + * Copy event info fid header followed by variable sized file handle + * and optionally followed by variable sized filename. + */ + info.hdr.info_type = name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME : + FAN_EVENT_INFO_TYPE_FID; info.hdr.len = len; - info.fsid = event->fid.fsid; + info.fsid = *fsid; if (copy_to_user(buf, &info, sizeof(info))) return -EFAULT; buf += sizeof(info); len -= sizeof(info); - handle.handle_type = event->fh_type; + if (WARN_ON_ONCE(len < sizeof(handle))) + return -EFAULT; + + handle.handle_type = fh->type; handle.handle_bytes = fh_len; if (copy_to_user(buf, &handle, sizeof(handle))) return -EFAULT; buf += sizeof(handle); len -= sizeof(handle); - /* - * For an inline fh, copy through stack to exclude the copy from - * usercopy hardening protections. - */ - fh = fanotify_event_fh(event); - if (fh_len <= FANOTIFY_INLINE_FH_LEN) { - memcpy(bounce, fh, fh_len); - fh = bounce; - } - if (copy_to_user(buf, fh, fh_len)) + if (WARN_ON_ONCE(len < fh_len)) + return -EFAULT; + + /* + * For an inline fh and inline file name, copy through stack to exclude + * the copy from usercopy hardening protections. + */ + fh_buf = fanotify_fh_buf(fh); + if (fh_len <= FANOTIFY_INLINE_FH_LEN) { + memcpy(bounce, fh_buf, fh_len); + fh_buf = bounce; + } + if (copy_to_user(buf, fh_buf, fh_len)) return -EFAULT; - /* Pad with 0's */ buf += fh_len; len -= fh_len; + + if (name_len) { + /* Copy the filename with terminating null */ + name_len++; + if (WARN_ON_ONCE(len < name_len)) + return -EFAULT; + + if (copy_to_user(buf, name, name_len)) + return -EFAULT; + + buf += name_len; + len -= name_len; + } + + /* Pad with 0's */ WARN_ON_ONCE(len < 0 || len >= FANOTIFY_EVENT_ALIGN); if (len > 0 && clear_user(buf, len)) return -EFAULT; - return 0; + return info_len; } static ssize_t copy_event_to_user(struct fsnotify_group *group, - struct fsnotify_event *fsn_event, + struct fanotify_event *event, char __user *buf, size_t count) { struct fanotify_event_metadata metadata; - struct fanotify_event *event; + struct path *path = fanotify_event_path(event); struct file *f = NULL; int ret, fd = FAN_NOFD; - pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event); + pr_debug("%s: group=%p event=%p\n", __func__, group, event); - event = container_of(fsn_event, struct fanotify_event, fse); - metadata.event_len = FAN_EVENT_METADATA_LEN; + metadata.event_len = FAN_EVENT_METADATA_LEN + + fanotify_event_info_len(event); metadata.metadata_len = FAN_EVENT_METADATA_LEN; metadata.vers = FANOTIFY_METADATA_VERSION; metadata.reserved = 0; metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS; metadata.pid = pid_vnr(event->pid); - if (fanotify_event_has_path(event)) { - fd = create_fd(group, event, &f); + if (path && path->mnt && path->dentry) { + fd = create_fd(group, path, &f); if (fd < 0) return fd; - } else if (fanotify_event_has_fid(event)) { - metadata.event_len += fanotify_event_info_len(event); } metadata.fd = fd; @@ -295,15 +336,39 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, if (copy_to_user(buf, &metadata, FAN_EVENT_METADATA_LEN)) goto out_close_fd; - if (fanotify_is_perm_event(event->mask)) - FANOTIFY_PE(fsn_event)->fd = fd; + buf += FAN_EVENT_METADATA_LEN; + count -= FAN_EVENT_METADATA_LEN; - if (fanotify_event_has_path(event)) { + if (fanotify_is_perm_event(event->mask)) + FANOTIFY_PERM(event)->fd = fd; + + if (f) fd_install(fd, f); - } else if (fanotify_event_has_fid(event)) { - ret = copy_fid_to_user(event, buf + FAN_EVENT_METADATA_LEN); + + /* Event info records order is: dir fid + name, child fid */ + if (fanotify_event_name_len(event)) { + struct fanotify_name_event *fne = FANOTIFY_NE(event); + + ret = copy_info_to_user(fanotify_event_fsid(event), + fanotify_event_dir_fh(event), + fne->name, fne->name_len, + buf, count); if (ret < 0) return ret; + + buf += ret; + count -= ret; + } + + if (fanotify_event_object_fh_len(event)) { + ret = copy_info_to_user(fanotify_event_fsid(event), + fanotify_event_object_fh(event), + NULL, 0, buf, count); + if (ret < 0) + return ret; + + buf += ret; + count -= ret; } return metadata.event_len; @@ -335,7 +400,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, size_t count, loff_t *pos) { struct fsnotify_group *group; - struct fsnotify_event *kevent; + struct fanotify_event *event; char __user *start; int ret; DEFINE_WAIT_FUNC(wait, woken_wake_function); @@ -347,13 +412,13 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, add_wait_queue(&group->notification_waitq, &wait); while (1) { - kevent = get_one_event(group, count); - if (IS_ERR(kevent)) { - ret = PTR_ERR(kevent); + event = get_one_event(group, count); + if (IS_ERR(event)) { + ret = PTR_ERR(event); break; } - if (!kevent) { + if (!event) { ret = -EAGAIN; if (file->f_flags & O_NONBLOCK) break; @@ -369,7 +434,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, continue; } - ret = copy_event_to_user(group, kevent, buf, count); + ret = copy_event_to_user(group, event, buf, count); if (unlikely(ret == -EOPENSTALE)) { /* * We cannot report events with stale fd so drop it. @@ -384,17 +449,17 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, * Permission events get queued to wait for response. Other * events can be destroyed now. */ - if (!fanotify_is_perm_event(FANOTIFY_E(kevent)->mask)) { - fsnotify_destroy_event(group, kevent); + if (!fanotify_is_perm_event(event->mask)) { + fsnotify_destroy_event(group, &event->fse); } else { if (ret <= 0) { spin_lock(&group->notification_lock); finish_permission_event(group, - FANOTIFY_PE(kevent), FAN_DENY); + FANOTIFY_PERM(event), FAN_DENY); wake_up(&group->fanotify_data.access_waitq); } else { spin_lock(&group->notification_lock); - list_add_tail(&kevent->list, + list_add_tail(&event->fse.list, &group->fanotify_data.access_list); spin_unlock(&group->notification_lock); } @@ -440,8 +505,6 @@ static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t static int fanotify_release(struct inode *ignored, struct file *file) { struct fsnotify_group *group = file->private_data; - struct fanotify_perm_event *event; - struct fsnotify_event *fsn_event; /* * Stop new events from arriving in the notification queue. since @@ -456,6 +519,8 @@ static int fanotify_release(struct inode *ignored, struct file *file) */ spin_lock(&group->notification_lock); while (!list_empty(&group->fanotify_data.access_list)) { + struct fanotify_perm_event *event; + event = list_first_entry(&group->fanotify_data.access_list, struct fanotify_perm_event, fae.fse.list); list_del_init(&event->fae.fse.list); @@ -469,12 +534,14 @@ static int fanotify_release(struct inode *ignored, struct file *file) * response is consumed and fanotify_get_response() returns. */ while (!fsnotify_notify_queue_is_empty(group)) { - fsn_event = fsnotify_remove_first_event(group); - if (!(FANOTIFY_E(fsn_event)->mask & FANOTIFY_PERM_EVENTS)) { + struct fanotify_event *event; + + event = FANOTIFY_E(fsnotify_remove_first_event(group)); + if (!(event->mask & FANOTIFY_PERM_EVENTS)) { spin_unlock(&group->notification_lock); - fsnotify_destroy_event(group, fsn_event); + fsnotify_destroy_event(group, &event->fse); } else { - finish_permission_event(group, FANOTIFY_PE(fsn_event), + finish_permission_event(group, FANOTIFY_PERM(event), FAN_ALLOW); } spin_lock(&group->notification_lock); @@ -824,7 +891,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) group->memcg = get_mem_cgroup_from_mm(current->mm); oevent = fanotify_alloc_event(group, NULL, FS_Q_OVERFLOW, NULL, - FSNOTIFY_EVENT_NONE, NULL); + FSNOTIFY_EVENT_NONE, NULL, NULL); if (unlikely(!oevent)) { fd = -ENOMEM; goto out_destroy_group; @@ -1139,7 +1206,10 @@ static int __init fanotify_user_setup(void) fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC|SLAB_ACCOUNT); - fanotify_event_cachep = KMEM_CACHE(fanotify_event, SLAB_PANIC); + fanotify_fid_event_cachep = KMEM_CACHE(fanotify_fid_event, + SLAB_PANIC); + fanotify_path_event_cachep = KMEM_CACHE(fanotify_path_event, + SLAB_PANIC); if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) { fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event, SLAB_PANIC); diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 46f225580009..72d332ce8e12 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -143,15 +143,13 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode) } /* Notify this dentry's parent about a child's events. */ -int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask) +int fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, + int data_type) { struct dentry *parent; struct inode *p_inode; int ret = 0; - if (!dentry) - dentry = path->dentry; - if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED)) return 0; @@ -168,12 +166,7 @@ int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask mask |= FS_EVENT_ON_CHILD; take_dentry_name_snapshot(&name, dentry); - if (path) - ret = fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH, - &name.name, 0); - else - ret = fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE, - &name.name, 0); + ret = fsnotify(p_inode, mask, data, data_type, &name.name, 0); release_dentry_name_snapshot(&name); } @@ -181,7 +174,7 @@ int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask return ret; } -EXPORT_SYMBOL_GPL(__fsnotify_parent); +EXPORT_SYMBOL_GPL(fsnotify_parent); static int send_to_group(struct inode *to_tell, __u32 mask, const void *data, @@ -318,6 +311,7 @@ static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info) int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, const struct qstr *file_name, u32 cookie) { + const struct path *path = fsnotify_data_path(data, data_is); struct fsnotify_iter_info iter_info = {}; struct super_block *sb = to_tell->i_sb; struct mount *mnt = NULL; @@ -325,8 +319,8 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, int ret = 0; __u32 test_mask = (mask & ALL_FSNOTIFY_EVENTS); - if (data_is == FSNOTIFY_EVENT_PATH) { - mnt = real_mount(((const struct path *)data)->mnt); + if (path) { + mnt = real_mount(path->mnt); mnt_or_sb_mask |= mnt->mnt_fsnotify_mask; } /* An event "on child" is not intended for a mount/sb mark */ @@ -389,7 +383,7 @@ static __init int fsnotify_init(void) { int ret; - BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 25); + BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 26); ret = init_srcu_struct(&fsnotify_mark_srcu); if (ret) diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index d510223d302c..2ebc89047153 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -39,7 +39,7 @@ static bool event_compare(struct fsnotify_event *old_fsn, if (old->mask & FS_IN_IGNORED) return false; if ((old->mask == new->mask) && - (old_fsn->inode == new_fsn->inode) && + (old_fsn->objectid == new_fsn->objectid) && (old->name_len == new->name_len) && (!old->name_len || !strcmp(old->name, new->name))) return true; @@ -61,6 +61,7 @@ int inotify_handle_event(struct fsnotify_group *group, const struct qstr *file_name, u32 cookie, struct fsnotify_iter_info *iter_info) { + const struct path *path = fsnotify_data_path(data, data_type); struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info); struct inotify_inode_mark *i_mark; struct inotify_event_info *event; @@ -73,12 +74,9 @@ int inotify_handle_event(struct fsnotify_group *group, return 0; if ((inode_mark->mask & FS_EXCL_UNLINK) && - (data_type == FSNOTIFY_EVENT_PATH)) { - const struct path *path = data; + path && d_unlinked(path->dentry)) + return 0; - if (d_unlinked(path->dentry)) - return 0; - } if (file_name) { len = file_name->len; alloc_len += len + 1; @@ -118,7 +116,7 @@ int inotify_handle_event(struct fsnotify_group *group, mask &= ~IN_ISDIR; fsn_event = &event->fse; - fsnotify_init_event(fsn_event, inode); + fsnotify_init_event(fsn_event, (unsigned long)inode); event->mask = mask; event->wd = i_mark->wd; event->sync_cookie = cookie; diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index 107537a543fd..81ffc8629fc4 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -635,7 +635,7 @@ static struct fsnotify_group *inotify_new_group(unsigned int max_events) return ERR_PTR(-ENOMEM); } group->overflow_event = &oevent->fse; - fsnotify_init_event(group->overflow_event, NULL); + fsnotify_init_event(group->overflow_event, 0); oevent->mask = FS_Q_OVERFLOW; oevent->wd = -1; oevent->sync_cookie = 0; diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index b79fa9bb7359..3049a6c06d9e 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -47,7 +47,8 @@ * Directory entry modification events - reported only to directory * where entry is modified and not to a watching parent. */ -#define FANOTIFY_DIRENT_EVENTS (FAN_MOVE | FAN_CREATE | FAN_DELETE) +#define FANOTIFY_DIRENT_EVENTS (FAN_MOVE | FAN_CREATE | FAN_DELETE | \ + FAN_DIR_MODIFY) /* Events that can only be reported with data type FSNOTIFY_EVENT_INODE */ #define FANOTIFY_INODE_EVENTS (FANOTIFY_DIRENT_EVENTS | \ diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index a2d5d175d3c1..5ab28f6c7d26 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -18,39 +18,63 @@ #include /* - * 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. */ -static inline int fsnotify_dirent(struct inode *dir, struct dentry *dentry, - __u32 mask) +static inline void fsnotify_name(struct inode *dir, __u32 mask, + struct inode *child, + const struct qstr *name, u32 cookie) { - return fsnotify(dir, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE, - &dentry->d_name, 0); + fsnotify(dir, mask, child, FSNOTIFY_EVENT_INODE, name, cookie); + /* + * Send another flavor of the event without child inode data and + * without the specific event type (e.g. FS_CREATE|FS_IS_DIR). + * The name is relative to the dir inode the event is reported to. + */ + fsnotify(dir, FS_DIR_MODIFY, dir, FSNOTIFY_EVENT_INODE, name, 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 void fsnotify_dirent(struct inode *dir, struct dentry *dentry, + __u32 mask) { - if (!dentry) - dentry = path->dentry; - - return __fsnotify_parent(path, dentry, mask); + fsnotify_name(dir, mask, d_inode(dentry), &dentry->d_name, 0); } /* - * Simple wrapper to consolidate calls fsnotify_parent()/fsnotify() when - * an event is on a path. + * Simple wrappers to consolidate calls fsnotify_parent()/fsnotify() 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) { - int ret = fsnotify_parent(path, NULL, mask); + struct inode *inode = d_inode(dentry); + if (S_ISDIR(inode->i_mode)) + mask |= FS_ISDIR; + + fsnotify_parent(dentry, mask, inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); +} + +static inline int fsnotify_file(struct file *file, __u32 mask) +{ + const struct path *path = &file->f_path; + struct inode *inode = file_inode(file); + int ret; + + if (file->f_mode & FMODE_NONOTIFY) + return 0; + + if (S_ISDIR(inode->i_mode)) + mask |= FS_ISDIR; + + ret = fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH); if (ret) return ret; + return fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); } @@ -58,19 +82,16 @@ static inline int fsnotify_path(struct inode *inode, const struct path *path, 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 +100,7 @@ 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); } /* @@ -122,10 +140,8 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, 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); + fsnotify_name(old_dir, old_dir_mask, source, old_name, fs_cookie); + fsnotify_name(new_dir, new_dir_mask, source, new_name, fs_cookie); if (target) fsnotify_link_count(target); @@ -180,12 +196,13 @@ static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) * 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(dir, FS_CREATE, inode, &new_dentry->d_name, 0); } /* @@ -229,15 +246,7 @@ 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 +254,7 @@ 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 +262,12 @@ 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 +275,10 @@ 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; + __u32 mask = (file->f_mode & FMODE_WRITE) ? FS_CLOSE_WRITE : + FS_CLOSE_NOWRITE; - if (S_ISDIR(inode->i_mode)) - mask |= FS_ISDIR; - - if (!(file->f_mode & FMODE_NONOTIFY)) - fsnotify_path(inode, path, mask); + fsnotify_file(file, mask); } /* @@ -295,14 +286,7 @@ 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 +295,6 @@ 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 +315,8 @@ 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; - - fsnotify_parent(NULL, dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); - } + if (mask) + fsnotify_dentry(dentry, mask); } #endif /* _LINUX_FS_NOTIFY_H */ diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 1915bdba2fad..f0c506405b54 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -47,18 +47,18 @@ #define FS_OPEN_PERM 0x00010000 /* open event in an permission hook */ #define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */ #define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */ +#define FS_DIR_MODIFY 0x00080000 /* Directory entry was modified */ #define FS_EXCL_UNLINK 0x04000000 /* do not send events if object is unlinked */ -#define FS_ISDIR 0x40000000 /* event occurred against dir */ -#define FS_IN_ONESHOT 0x80000000 /* only send event once */ - -#define FS_DN_RENAME 0x10000000 /* file renamed */ -#define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */ - /* This inode cares about things that happen to its children. Always set for * dnotify and inotify. */ #define FS_EVENT_ON_CHILD 0x08000000 +#define FS_DN_RENAME 0x10000000 /* file renamed */ +#define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */ +#define FS_ISDIR 0x40000000 /* event occurred against dir */ +#define FS_IN_ONESHOT 0x80000000 /* only send event once */ + #define FS_MOVE (FS_MOVED_FROM | FS_MOVED_TO) /* @@ -67,7 +67,8 @@ * The watching parent may get an FS_ATTRIB|FS_EVENT_ON_CHILD event * when a directory entry inside a child subdir changes. */ -#define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE) +#define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE | \ + FS_DIR_MODIFY) #define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \ FS_OPEN_EXEC_PERM) @@ -133,8 +134,7 @@ struct fsnotify_ops { */ struct fsnotify_event { struct list_head list; - /* inode may ONLY be dereferenced during handle_event(). */ - struct inode *inode; /* either the inode the event happened to or its parent */ + unsigned long objectid; /* identifier for queue merges */ }; /* @@ -213,10 +213,36 @@ struct fsnotify_group { }; }; -/* when calling fsnotify tell it if the data is a path or inode */ -#define FSNOTIFY_EVENT_NONE 0 -#define FSNOTIFY_EVENT_PATH 1 -#define FSNOTIFY_EVENT_INODE 2 +/* When calling fsnotify tell it if the data is a path or inode */ +enum fsnotify_data_type { + FSNOTIFY_EVENT_NONE, + FSNOTIFY_EVENT_PATH, + FSNOTIFY_EVENT_INODE, +}; + +static inline const struct inode *fsnotify_data_inode(const void *data, + int data_type) +{ + switch (data_type) { + case FSNOTIFY_EVENT_INODE: + return data; + case FSNOTIFY_EVENT_PATH: + return d_inode(((const struct path *)data)->dentry); + default: + return NULL; + } +} + +static inline const struct path *fsnotify_data_path(const void *data, + int data_type) +{ + switch (data_type) { + case FSNOTIFY_EVENT_PATH: + return data; + default: + return NULL; + } +} enum fsnotify_obj_type { FSNOTIFY_OBJ_TYPE_INODE, @@ -351,9 +377,10 @@ struct fsnotify_mark { /* called from the vfs helpers */ /* main fsnotify call to send events */ -extern int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, - const struct qstr *name, u32 cookie); -extern int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask); +extern int fsnotify(struct inode *to_tell, __u32 mask, const void *data, + int data_type, const struct qstr *name, u32 cookie); +extern int fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, + int data_type); extern void __fsnotify_inode_delete(struct inode *inode); extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt); extern void fsnotify_sb_delete(struct super_block *sb); @@ -500,21 +527,22 @@ extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info); extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info); static inline void fsnotify_init_event(struct fsnotify_event *event, - struct inode *inode) + unsigned long objectid) { INIT_LIST_HEAD(&event->list); - event->inode = inode; + event->objectid = objectid; } #else -static inline int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, - const struct qstr *name, u32 cookie) +static inline int fsnotify(struct inode *to_tell, __u32 mask, const void *data, + int data_type, const struct qstr *name, u32 cookie) { return 0; } -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) { return 0; } diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h index b9effa6f8503..a88c7c6d0692 100644 --- a/include/uapi/linux/fanotify.h +++ b/include/uapi/linux/fanotify.h @@ -24,10 +24,11 @@ #define FAN_OPEN_PERM 0x00010000 /* File open in perm check */ #define FAN_ACCESS_PERM 0x00020000 /* File accessed in perm check */ #define FAN_OPEN_EXEC_PERM 0x00040000 /* File open/exec in perm check */ +#define FAN_DIR_MODIFY 0x00080000 /* Directory entry was modified */ -#define FAN_ONDIR 0x40000000 /* event occurred against dir */ +#define FAN_EVENT_ON_CHILD 0x08000000 /* Interested in child events */ -#define FAN_EVENT_ON_CHILD 0x08000000 /* interested in child events */ +#define FAN_ONDIR 0x40000000 /* Event occurred against dir */ /* helper events */ #define FAN_CLOSE (FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */ @@ -116,6 +117,7 @@ struct fanotify_event_metadata { }; #define FAN_EVENT_INFO_TYPE_FID 1 +#define FAN_EVENT_INFO_TYPE_DFID_NAME 2 /* Variable length info record following event metadata */ struct fanotify_event_info_header { @@ -124,7 +126,12 @@ struct fanotify_event_info_header { __u16 len; }; -/* Unique file identifier info record */ +/* + * Unique file identifier info record. This is used both for + * FAN_EVENT_INFO_TYPE_FID records and for FAN_EVENT_INFO_TYPE_DFID_NAME + * records. For FAN_EVENT_INFO_TYPE_DFID_NAME there is additionally a null + * terminated name immediately after the file handle. + */ struct fanotify_event_info_fid { struct fanotify_event_info_header hdr; __kernel_fsid_t fsid; diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c index f0d243318452..3596448bfdab 100644 --- a/kernel/audit_fsnotify.c +++ b/kernel/audit_fsnotify.c @@ -160,23 +160,14 @@ static int audit_mark_handle_event(struct fsnotify_group *group, { struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info); struct audit_fsnotify_mark *audit_mark; - const struct inode *inode = NULL; + const struct inode *inode = fsnotify_data_inode(data, data_type); audit_mark = container_of(inode_mark, struct audit_fsnotify_mark, mark); BUG_ON(group != audit_fsnotify_group); - switch (data_type) { - case (FSNOTIFY_EVENT_PATH): - inode = ((const struct path *)data)->dentry->d_inode; - break; - case (FSNOTIFY_EVENT_INODE): - inode = (const struct inode *)data; - break; - default: - BUG(); + if (WARN_ON(!inode)) return 0; - } if (mask & (FS_CREATE|FS_MOVED_TO|FS_DELETE|FS_MOVED_FROM)) { if (audit_compare_dname_path(dname, audit_mark->path, AUDIT_NAME_FULL)) diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c index 8a8fd732ff6d..e09c551ae52d 100644 --- a/kernel/audit_watch.c +++ b/kernel/audit_watch.c @@ -471,25 +471,13 @@ static int audit_watch_handle_event(struct fsnotify_group *group, struct fsnotify_iter_info *iter_info) { struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info); - const struct inode *inode; + const struct inode *inode = fsnotify_data_inode(data, data_type); struct audit_parent *parent; parent = container_of(inode_mark, struct audit_parent, mark); BUG_ON(group != audit_watch_group); - - switch (data_type) { - case (FSNOTIFY_EVENT_PATH): - inode = d_backing_inode(((const struct path *)data)->dentry); - break; - case (FSNOTIFY_EVENT_INODE): - inode = (const struct inode *)data; - break; - default: - BUG(); - inode = NULL; - break; - } + WARN_ON(!inode); if (mask & (FS_CREATE|FS_MOVED_TO) && inode) audit_update_watch(parent, dname, inode->i_sb->s_dev, inode->i_ino, 0);