diff options
Diffstat (limited to 'fs/notify/fanotify/fanotify.c')
-rw-r--r-- | fs/notify/fanotify/fanotify.c | 328 |
1 files changed, 267 insertions, 61 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 057abd2cf887..985e995d2a39 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -76,8 +76,10 @@ static bool fanotify_info_equal(struct fanotify_info *info1, struct fanotify_info *info2) { if (info1->dir_fh_totlen != info2->dir_fh_totlen || + info1->dir2_fh_totlen != info2->dir2_fh_totlen || info1->file_fh_totlen != info2->file_fh_totlen || - info1->name_len != info2->name_len) + info1->name_len != info2->name_len || + info1->name2_len != info2->name2_len) return false; if (info1->dir_fh_totlen && @@ -85,14 +87,24 @@ static bool fanotify_info_equal(struct fanotify_info *info1, fanotify_info_dir_fh(info2))) return false; + if (info1->dir2_fh_totlen && + !fanotify_fh_equal(fanotify_info_dir2_fh(info1), + fanotify_info_dir2_fh(info2))) + return false; + if (info1->file_fh_totlen && !fanotify_fh_equal(fanotify_info_file_fh(info1), fanotify_info_file_fh(info2))) return false; - return !info1->name_len || - !memcmp(fanotify_info_name(info1), fanotify_info_name(info2), - info1->name_len); + if (info1->name_len && + memcmp(fanotify_info_name(info1), fanotify_info_name(info2), + info1->name_len)) + return false; + + return !info1->name2_len || + !memcmp(fanotify_info_name2(info1), fanotify_info_name2(info2), + info1->name2_len); } static bool fanotify_name_event_equal(struct fanotify_name_event *fne1, @@ -111,6 +123,16 @@ static bool fanotify_name_event_equal(struct fanotify_name_event *fne1, return fanotify_info_equal(info1, info2); } +static bool fanotify_error_event_equal(struct fanotify_error_event *fee1, + struct fanotify_error_event *fee2) +{ + /* Error events against the same file system are always merged. */ + if (!fanotify_fsid_equal(&fee1->fsid, &fee2->fsid)) + return false; + + return true; +} + static bool fanotify_should_merge(struct fanotify_event *old, struct fanotify_event *new) { @@ -131,6 +153,13 @@ static bool fanotify_should_merge(struct fanotify_event *old, if ((old->mask & FS_ISDIR) != (new->mask & FS_ISDIR)) return false; + /* + * FAN_RENAME event is reported with special info record types, + * so we cannot merge it with other events. + */ + if ((old->mask & FAN_RENAME) != (new->mask & FAN_RENAME)) + return false; + switch (old->type) { case FANOTIFY_EVENT_TYPE_PATH: return fanotify_path_equal(fanotify_event_path(old), @@ -141,6 +170,9 @@ static bool fanotify_should_merge(struct fanotify_event *old, case FANOTIFY_EVENT_TYPE_FID_NAME: return fanotify_name_event_equal(FANOTIFY_NE(old), FANOTIFY_NE(new)); + case FANOTIFY_EVENT_TYPE_FS_ERROR: + return fanotify_error_event_equal(FANOTIFY_EE(old), + FANOTIFY_EE(new)); default: WARN_ON_ONCE(1); } @@ -176,6 +208,10 @@ static int fanotify_merge(struct fsnotify_group *group, break; if (fanotify_should_merge(old, new)) { old->mask |= new->mask; + + if (fanotify_is_error_event(old->mask)) + FANOTIFY_EE(old)->err_count++; + return 1; } } @@ -255,8 +291,9 @@ out: */ static u32 fanotify_group_event_mask(struct fsnotify_group *group, struct fsnotify_iter_info *iter_info, - u32 event_mask, const void *data, - int data_type, struct inode *dir) + u32 *match_mask, u32 event_mask, + const void *data, int data_type, + struct inode *dir) { __u32 marks_mask = 0, marks_ignored_mask = 0; __u32 test_mask, user_mask = FANOTIFY_OUTGOING_EVENTS | @@ -282,7 +319,7 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, return 0; } - fsnotify_foreach_obj_type(type) { + fsnotify_foreach_iter_type(type) { if (!fsnotify_iter_should_report_type(iter_info, type)) continue; mark = iter_info->marks[type]; @@ -301,11 +338,14 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, * If the event is on a child and this mark is on a parent not * watching children, don't send it! */ - if (type == FSNOTIFY_OBJ_TYPE_PARENT && + if (type == FSNOTIFY_ITER_TYPE_PARENT && !(mark->mask & FS_EVENT_ON_CHILD)) continue; marks_mask |= mark->mask; + + /* Record the mark types of this group that matched the event */ + *match_mask |= 1U << type; } test_mask = event_mask & marks_mask & ~marks_ignored_mask; @@ -343,13 +383,23 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, static int fanotify_encode_fh_len(struct inode *inode) { int dwords = 0; + int fh_len; if (!inode) return 0; exportfs_encode_inode_fh(inode, NULL, &dwords, NULL); + fh_len = dwords << 2; - return dwords << 2; + /* + * struct fanotify_error_event might be preallocated and is + * limited to MAX_HANDLE_SZ. This should never happen, but + * safeguard by forcing an invalid file handle. + */ + if (WARN_ON_ONCE(fh_len > MAX_HANDLE_SZ)) + return 0; + + return fh_len; } /* @@ -370,15 +420,21 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode, fh->type = FILEID_ROOT; fh->len = 0; fh->flags = 0; + + /* + * Invalid FHs are used by FAN_FS_ERROR for errors not + * linked to any inode. The f_handle won't be reported + * back to userspace. + */ if (!inode) - return 0; + goto out; /* * !gpf means preallocated variable size fh, but fh_len could * be zero in that case if encoding fh len failed. */ err = -ENOENT; - if (fh_len < 4 || WARN_ON_ONCE(fh_len % 4)) + if (fh_len < 4 || WARN_ON_ONCE(fh_len % 4) || fh_len > MAX_HANDLE_SZ) goto out_err; /* No external buffer in a variable size allocated fh */ @@ -403,8 +459,13 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode, fh->type = type; fh->len = fh_len; - /* Mix fh into event merge key */ - *hash ^= fanotify_hash_fh(fh); +out: + /* + * Mix fh into event merge key. Hash might be NULL in case of + * unhashed FID events (i.e. FAN_FS_ERROR). + */ + if (hash) + *hash ^= fanotify_hash_fh(fh); return FANOTIFY_FH_HDR_LEN + fh_len; @@ -420,17 +481,41 @@ out_err: } /* - * The inode to use as identifier when reporting fid depends on the event. - * Report the modified directory inode on dirent modification events. - * Report the "victim" inode otherwise. + * FAN_REPORT_FID is ambiguous in that it reports the fid of the child for + * some events and the fid of the parent for create/delete/move events. + * + * With the FAN_REPORT_TARGET_FID flag, the fid of the child is reported + * also in create/delete/move events in addition to the fid of the parent + * and the name of the child. + */ +static inline bool fanotify_report_child_fid(unsigned int fid_mode, u32 mask) +{ + if (mask & ALL_FSNOTIFY_DIRENT_EVENTS) + return (fid_mode & FAN_REPORT_TARGET_FID); + + return (fid_mode & FAN_REPORT_FID) && !(mask & FAN_ONDIR); +} + +/* + * The inode to use as identifier when reporting fid depends on the event + * and the group flags. + * + * With the group flag FAN_REPORT_TARGET_FID, always report the child fid. + * + * Without the group flag FAN_REPORT_TARGET_FID, report the modified directory + * fid on dirent events and the child fid otherwise. + * * For example: - * FS_ATTRIB reports the child inode even if reported on a watched parent. - * FS_CREATE reports the modified dir inode and not the created inode. + * FS_ATTRIB reports the child fid even if reported on a watched parent. + * FS_CREATE reports the modified dir fid without FAN_REPORT_TARGET_FID. + * and reports the created child fid with FAN_REPORT_TARGET_FID. */ static struct inode *fanotify_fid_inode(u32 event_mask, const void *data, - int data_type, struct inode *dir) + int data_type, struct inode *dir, + unsigned int fid_mode) { - if (event_mask & ALL_FSNOTIFY_DIRENT_EVENTS) + if ((event_mask & ALL_FSNOTIFY_DIRENT_EVENTS) && + !(fid_mode & FAN_REPORT_TARGET_FID)) return dir; return fsnotify_data_inode(data, data_type); @@ -452,7 +537,7 @@ static struct inode *fanotify_dfid_inode(u32 event_mask, const void *data, if (event_mask & ALL_FSNOTIFY_DIRENT_EVENTS) return dir; - if (S_ISDIR(inode->i_mode)) + if (inode && S_ISDIR(inode->i_mode)) return inode; return dir; @@ -514,25 +599,34 @@ static struct fanotify_event *fanotify_alloc_fid_event(struct inode *id, return &ffe->fae; } -static struct fanotify_event *fanotify_alloc_name_event(struct inode *id, +static struct fanotify_event *fanotify_alloc_name_event(struct inode *dir, __kernel_fsid_t *fsid, const struct qstr *name, struct inode *child, + struct dentry *moved, unsigned int *hash, gfp_t gfp) { struct fanotify_name_event *fne; struct fanotify_info *info; struct fanotify_fh *dfh, *ffh; - unsigned int dir_fh_len = fanotify_encode_fh_len(id); + struct inode *dir2 = moved ? d_inode(moved->d_parent) : NULL; + const struct qstr *name2 = moved ? &moved->d_name : NULL; + unsigned int dir_fh_len = fanotify_encode_fh_len(dir); + unsigned int dir2_fh_len = fanotify_encode_fh_len(dir2); unsigned int child_fh_len = fanotify_encode_fh_len(child); - unsigned int size; - - size = sizeof(*fne) + FANOTIFY_FH_HDR_LEN + dir_fh_len; + unsigned long name_len = name ? name->len : 0; + unsigned long name2_len = name2 ? name2->len : 0; + unsigned int len, size; + + /* Reserve terminating null byte even for empty name */ + size = sizeof(*fne) + name_len + name2_len + 2; + if (dir_fh_len) + size += FANOTIFY_FH_HDR_LEN + dir_fh_len; + if (dir2_fh_len) + size += FANOTIFY_FH_HDR_LEN + dir2_fh_len; if (child_fh_len) size += FANOTIFY_FH_HDR_LEN + child_fh_len; - if (name) - size += name->len + 1; fne = kmalloc(size, gfp); if (!fne) return NULL; @@ -542,40 +636,97 @@ static struct fanotify_event *fanotify_alloc_name_event(struct inode *id, *hash ^= fanotify_hash_fsid(fsid); info = &fne->info; fanotify_info_init(info); - dfh = fanotify_info_dir_fh(info); - info->dir_fh_totlen = fanotify_encode_fh(dfh, id, dir_fh_len, hash, 0); + if (dir_fh_len) { + dfh = fanotify_info_dir_fh(info); + len = fanotify_encode_fh(dfh, dir, dir_fh_len, hash, 0); + fanotify_info_set_dir_fh(info, len); + } + if (dir2_fh_len) { + dfh = fanotify_info_dir2_fh(info); + len = fanotify_encode_fh(dfh, dir2, dir2_fh_len, hash, 0); + fanotify_info_set_dir2_fh(info, len); + } if (child_fh_len) { ffh = fanotify_info_file_fh(info); - info->file_fh_totlen = fanotify_encode_fh(ffh, child, - child_fh_len, hash, 0); + len = fanotify_encode_fh(ffh, child, child_fh_len, hash, 0); + fanotify_info_set_file_fh(info, len); } - if (name) { - long salt = name->len; - + if (name_len) { fanotify_info_copy_name(info, name); - *hash ^= full_name_hash((void *)salt, name->name, name->len); + *hash ^= full_name_hash((void *)name_len, name->name, name_len); + } + if (name2_len) { + fanotify_info_copy_name2(info, name2); + *hash ^= full_name_hash((void *)name2_len, name2->name, + name2_len); } - pr_debug("%s: ino=%lu size=%u dir_fh_len=%u child_fh_len=%u name_len=%u name='%.*s'\n", - __func__, id->i_ino, size, dir_fh_len, child_fh_len, + pr_debug("%s: size=%u dir_fh_len=%u child_fh_len=%u name_len=%u name='%.*s'\n", + __func__, size, dir_fh_len, child_fh_len, info->name_len, info->name_len, fanotify_info_name(info)); + if (dir2_fh_len) { + pr_debug("%s: dir2_fh_len=%u name2_len=%u name2='%.*s'\n", + __func__, dir2_fh_len, info->name2_len, + info->name2_len, fanotify_info_name2(info)); + } + return &fne->fae; } -static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, - u32 mask, const void *data, - int data_type, struct inode *dir, - const struct qstr *file_name, - __kernel_fsid_t *fsid) +static struct fanotify_event *fanotify_alloc_error_event( + struct fsnotify_group *group, + __kernel_fsid_t *fsid, + const void *data, int data_type, + unsigned int *hash) +{ + struct fs_error_report *report = + fsnotify_data_error_report(data, data_type); + struct inode *inode; + struct fanotify_error_event *fee; + int fh_len; + + if (WARN_ON_ONCE(!report)) + return NULL; + + fee = mempool_alloc(&group->fanotify_data.error_events_pool, GFP_NOFS); + if (!fee) + return NULL; + + fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR; + fee->error = report->error; + fee->err_count = 1; + fee->fsid = *fsid; + + inode = report->inode; + fh_len = fanotify_encode_fh_len(inode); + + /* Bad fh_len. Fallback to using an invalid fh. Should never happen. */ + if (!fh_len && inode) + inode = NULL; + + fanotify_encode_fh(&fee->object_fh, inode, fh_len, NULL, 0); + + *hash ^= fanotify_hash_fsid(fsid); + + return &fee->fae; +} + +static struct fanotify_event *fanotify_alloc_event( + struct fsnotify_group *group, + u32 mask, const void *data, int data_type, + struct inode *dir, const struct qstr *file_name, + __kernel_fsid_t *fsid, u32 match_mask) { struct fanotify_event *event = NULL; gfp_t gfp = GFP_KERNEL_ACCOUNT; - struct inode *id = fanotify_fid_inode(mask, data, data_type, dir); + unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS); + struct inode *id = fanotify_fid_inode(mask, data, data_type, dir, + fid_mode); struct inode *dirid = fanotify_dfid_inode(mask, data, data_type, dir); const struct path *path = fsnotify_data_path(data, data_type); - unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS); struct mem_cgroup *old_memcg; + struct dentry *moved = NULL; struct inode *child = NULL; bool name_event = false; unsigned int hash = 0; @@ -584,11 +735,10 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, if ((fid_mode & FAN_REPORT_DIR_FID) && dirid) { /* - * With both flags FAN_REPORT_DIR_FID and FAN_REPORT_FID, we - * report the child fid for events reported on a non-dir child + * For certain events and group flags, report the child fid * in addition to reporting the parent fid and maybe child name. */ - if ((fid_mode & FAN_REPORT_FID) && id != dirid && !ondir) + if (fanotify_report_child_fid(fid_mode, mask) && id != dirid) child = id; id = dirid; @@ -612,6 +762,38 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, } else if ((mask & ALL_FSNOTIFY_DIRENT_EVENTS) || !ondir) { name_event = true; } + + /* + * In the special case of FAN_RENAME event, use the match_mask + * to determine if we need to report only the old parent+name, + * only the new parent+name or both. + * 'dirid' and 'file_name' are the old parent+name and + * 'moved' has the new parent+name. + */ + if (mask & FAN_RENAME) { + bool report_old, report_new; + + if (WARN_ON_ONCE(!match_mask)) + return NULL; + + /* Report both old and new parent+name if sb watching */ + report_old = report_new = + match_mask & (1U << FSNOTIFY_ITER_TYPE_SB); + report_old |= + match_mask & (1U << FSNOTIFY_ITER_TYPE_INODE); + report_new |= + match_mask & (1U << FSNOTIFY_ITER_TYPE_INODE2); + + if (!report_old) { + /* Do not report old parent+name */ + dirid = NULL; + file_name = NULL; + } + if (report_new) { + /* Report new parent+name */ + moved = fsnotify_data_dentry(data, data_type); + } + } } /* @@ -630,9 +812,12 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, if (fanotify_is_perm_event(mask)) { event = fanotify_alloc_perm_event(path, gfp); - } else if (name_event && (file_name || child)) { - event = fanotify_alloc_name_event(id, fsid, file_name, child, - &hash, gfp); + } else if (fanotify_is_error_event(mask)) { + event = fanotify_alloc_error_event(group, fsid, data, + data_type, &hash); + } else if (name_event && (file_name || moved || child)) { + event = fanotify_alloc_name_event(dirid, fsid, file_name, child, + moved, &hash, gfp); } else if (fid_mode) { event = fanotify_alloc_fid_event(id, fsid, &hash, gfp); } else { @@ -667,7 +852,7 @@ static __kernel_fsid_t fanotify_get_fsid(struct fsnotify_iter_info *iter_info) int type; __kernel_fsid_t fsid = {}; - fsnotify_foreach_obj_type(type) { + fsnotify_foreach_iter_type(type) { struct fsnotify_mark_connector *conn; if (!fsnotify_iter_should_report_type(iter_info, type)) @@ -702,6 +887,9 @@ static void fanotify_insert_event(struct fsnotify_group *group, assert_spin_locked(&group->notification_lock); + if (!fanotify_is_hashed_event(event->mask)) + return; + pr_debug("%s: group=%p event=%p bucket=%u\n", __func__, group, event, bucket); @@ -718,6 +906,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask, struct fanotify_event *event; struct fsnotify_event *fsn_event; __kernel_fsid_t fsid = {}; + u32 match_mask = 0; BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS); BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY); @@ -738,15 +927,18 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask, BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR); BUILD_BUG_ON(FAN_OPEN_EXEC != FS_OPEN_EXEC); BUILD_BUG_ON(FAN_OPEN_EXEC_PERM != FS_OPEN_EXEC_PERM); + BUILD_BUG_ON(FAN_FS_ERROR != FS_ERROR); + BUILD_BUG_ON(FAN_RENAME != FS_RENAME); - BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 19); + BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 21); - mask = fanotify_group_event_mask(group, iter_info, mask, data, - data_type, dir); + mask = fanotify_group_event_mask(group, iter_info, &match_mask, + mask, data, data_type, dir); if (!mask) return 0; - pr_debug("%s: group=%p mask=%x\n", __func__, group, mask); + pr_debug("%s: group=%p mask=%x report_mask=%x\n", __func__, + group, mask, match_mask); if (fanotify_is_perm_event(mask)) { /* @@ -765,7 +957,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask, } event = fanotify_alloc_event(group, mask, data, data_type, dir, - file_name, &fsid); + file_name, &fsid, match_mask); ret = -ENOMEM; if (unlikely(!event)) { /* @@ -778,9 +970,8 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask, } fsn_event = &event->fse; - ret = fsnotify_add_event(group, fsn_event, fanotify_merge, - fanotify_is_hashed_event(mask) ? - fanotify_insert_event : NULL); + ret = fsnotify_insert_event(group, fsn_event, fanotify_merge, + fanotify_insert_event); if (ret) { /* Permission events shouldn't be merged */ BUG_ON(ret == 1 && mask & FANOTIFY_PERM_EVENTS); @@ -805,6 +996,9 @@ static void fanotify_free_group_priv(struct fsnotify_group *group) if (group->fanotify_data.ucounts) dec_ucount(group->fanotify_data.ucounts, UCOUNT_FANOTIFY_GROUPS); + + if (mempool_initialized(&group->fanotify_data.error_events_pool)) + mempool_exit(&group->fanotify_data.error_events_pool); } static void fanotify_free_path_event(struct fanotify_event *event) @@ -833,7 +1027,16 @@ static void fanotify_free_name_event(struct fanotify_event *event) kfree(FANOTIFY_NE(event)); } -static void fanotify_free_event(struct fsnotify_event *fsn_event) +static void fanotify_free_error_event(struct fsnotify_group *group, + struct fanotify_event *event) +{ + struct fanotify_error_event *fee = FANOTIFY_EE(event); + + mempool_free(fee, &group->fanotify_data.error_events_pool); +} + +static void fanotify_free_event(struct fsnotify_group *group, + struct fsnotify_event *fsn_event) { struct fanotify_event *event; @@ -855,6 +1058,9 @@ static void fanotify_free_event(struct fsnotify_event *fsn_event) case FANOTIFY_EVENT_TYPE_OVERFLOW: kfree(event); break; + case FANOTIFY_EVENT_TYPE_FS_ERROR: + fanotify_free_error_event(group, event); + break; default: WARN_ON_ONCE(1); } |