diff options
Diffstat (limited to 'fs/notify/inotify/inotify_fsnotify.c')
| -rw-r--r-- | fs/notify/inotify/inotify_fsnotify.c | 104 |
1 files changed, 59 insertions, 45 deletions
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index 8b73332735ba..7c326ec2e8a8 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * fs/inotify_user.c - inotify support for userspace * @@ -9,17 +10,7 @@ * Copyright 2006 Hewlett-Packard Development Company, L.P. * * Copyright (C) 2009 Eric Paris <Red Hat Inc> - * inotify was largely rewriten to make use of the fsnotify infrastructure - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the - * Free Software Foundation; either version 2, or (at your option) any - * later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. + * inotify was largely rewritten to make use of the fsnotify infrastructure */ #include <linux/dcache.h> /* d_unlinked */ @@ -31,6 +22,7 @@ #include <linux/types.h> #include <linux/sched.h> #include <linux/sched/user.h> +#include <linux/sched/mm.h> #include "inotify.h" @@ -42,73 +34,94 @@ static bool event_compare(struct fsnotify_event *old_fsn, { struct inotify_event_info *old, *new; - if (old_fsn->mask & FS_IN_IGNORED) - return false; old = INOTIFY_E(old_fsn); new = INOTIFY_E(new_fsn); - if ((old_fsn->mask == new_fsn->mask) && - (old_fsn->inode == new_fsn->inode) && + if (old->mask & FS_IN_IGNORED) + return false; + if ((old->mask == new->mask) && + (old->wd == new->wd) && (old->name_len == new->name_len) && (!old->name_len || !strcmp(old->name, new->name))) return true; return false; } -static int inotify_merge(struct list_head *list, - struct fsnotify_event *event) +static int inotify_merge(struct fsnotify_group *group, + struct fsnotify_event *event) { + struct list_head *list = &group->notification_list; struct fsnotify_event *last_event; last_event = list_entry(list->prev, struct fsnotify_event, list); return event_compare(last_event, event); } -int inotify_handle_event(struct fsnotify_group *group, - struct inode *inode, - struct fsnotify_mark *inode_mark, - struct fsnotify_mark *vfsmount_mark, - u32 mask, const void *data, int data_type, - const unsigned char *file_name, u32 cookie, - struct fsnotify_iter_info *iter_info) +int inotify_handle_inode_event(struct fsnotify_mark *inode_mark, u32 mask, + struct inode *inode, struct inode *dir, + const struct qstr *name, u32 cookie) { struct inotify_inode_mark *i_mark; struct inotify_event_info *event; struct fsnotify_event *fsn_event; + struct fsnotify_group *group = inode_mark->group; int ret; - int len = 0; + int len = 0, wd; int alloc_len = sizeof(struct inotify_event_info); + struct mem_cgroup *old_memcg; - BUG_ON(vfsmount_mark); - - if ((inode_mark->mask & FS_EXCL_UNLINK) && - (data_type == FSNOTIFY_EVENT_PATH)) { - const struct path *path = data; - - if (d_unlinked(path->dentry)) - return 0; - } - if (file_name) { - len = strlen(file_name); + if (name) { + len = name->len; alloc_len += len + 1; } - pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode, + pr_debug("%s: group=%p mark=%p mask=%x\n", __func__, group, inode_mark, mask); i_mark = container_of(inode_mark, struct inotify_inode_mark, fsn_mark); - event = kmalloc(alloc_len, GFP_KERNEL); - if (unlikely(!event)) + /* + * We can be racing with mark being detached. Don't report event with + * invalid wd. + */ + wd = READ_ONCE(i_mark->wd); + if (wd == -1) + return 0; + /* + * Whoever is interested in the event, pays for the allocation. Do not + * trigger OOM killer in the target monitoring memcg as it may have + * security repercussion. + */ + old_memcg = set_active_memcg(group->memcg); + event = kmalloc(alloc_len, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL); + set_active_memcg(old_memcg); + + if (unlikely(!event)) { + /* + * Treat lost event due to ENOMEM the same way as queue + * overflow to let userspace know event was lost. + */ + fsnotify_queue_overflow(group); return -ENOMEM; + } + + /* + * We now report FS_ISDIR flag with MOVE_SELF and DELETE_SELF events + * for fanotify. inotify never reported IN_ISDIR with those events. + * It looks like an oversight, but to avoid the risk of breaking + * existing inotify programs, mask the flag out from those events. + */ + if (mask & (IN_MOVE_SELF | IN_DELETE_SELF)) + mask &= ~IN_ISDIR; fsn_event = &event->fse; - fsnotify_init_event(fsn_event, inode, mask); - event->wd = i_mark->wd; + fsnotify_init_event(fsn_event); + event->mask = mask; + event->wd = wd; event->sync_cookie = cookie; event->name_len = len; if (len) - strcpy(event->name, file_name); + strscpy(event->name, name->name, event->name_len + 1); ret = fsnotify_add_event(group, fsn_event, inotify_merge); if (ret) { @@ -116,7 +129,7 @@ int inotify_handle_event(struct fsnotify_group *group, fsnotify_destroy_event(group, fsn_event); } - if (inode_mark->mask & IN_ONESHOT) + if (inode_mark->flags & FSNOTIFY_MARK_FLAG_IN_ONESHOT) fsnotify_destroy_mark(inode_mark, group); return 0; @@ -171,7 +184,8 @@ static void inotify_free_group_priv(struct fsnotify_group *group) dec_inotify_instances(group->inotify_data.ucounts); } -static void inotify_free_event(struct fsnotify_event *fsn_event) +static void inotify_free_event(struct fsnotify_group *group, + struct fsnotify_event *fsn_event) { kfree(INOTIFY_E(fsn_event)); } @@ -187,7 +201,7 @@ static void inotify_free_mark(struct fsnotify_mark *fsn_mark) } const struct fsnotify_ops inotify_fsnotify_ops = { - .handle_event = inotify_handle_event, + .handle_inode_event = inotify_handle_inode_event, .free_group_priv = inotify_free_group_priv, .free_event = inotify_free_event, .freeing_mark = inotify_freeing_mark, |