diff options
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 185 |
1 files changed, 133 insertions, 52 deletions
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 0535193..cb7a0c5 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -295,31 +295,83 @@ out: return ret; } -static int fanotify_remove_mark(struct fsnotify_group *group, - struct inode *inode, - __u32 mask) +static void fanotify_update_object_mask(struct fsnotify_group *group, + struct inode *inode, + struct vfsmount *mnt, + struct fsnotify_mark *fsn_mark, + unsigned int flags, + __u32 mask) { - struct fsnotify_mark *fsn_mark; - __u32 new_mask; - - pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, - group, inode, mask); + __u32 old_mask, new_mask; - fsn_mark = fsnotify_find_inode_mark(group, inode); - if (!fsn_mark) - return -ENOENT; + pr_debug("%s: group=%p inode=%p mnt=%p fsn_mark=%p flags=%x mask=%x\n", + __func__, group, inode, mnt, fsn_mark, flags, mask); spin_lock(&fsn_mark->lock); - fsn_mark->mask &= ~mask; + old_mask = fsn_mark->mask; + if (flags & FAN_MARK_ADD) + fsn_mark->mask |= mask; + else if (flags & FAN_MARK_REMOVE) + fsn_mark->mask &= ~mask; + else + BUG(); new_mask = fsn_mark->mask; spin_unlock(&fsn_mark->lock); if (!new_mask) fsnotify_destroy_mark(fsn_mark); + + /* we made changes to a mask, update the group mask and the object mask + * so things happen quickly. */ + if (old_mask != new_mask) { + __u32 dropped, do_object, do_group; + + /* more bits in old than in new? */ + dropped = (old_mask & ~new_mask); + /* more bits in this fsn_mark than the group? */ + do_group = (new_mask & ~group->mask); + + if (inode) { + /* more bits in this fsn_mark than the object's mask? */ + do_object = (new_mask & ~inode->i_fsnotify_mask); + /* update the object with this new fsn_mark */ + if (dropped || do_object) + fsnotify_recalc_inode_mask(inode); + } else if (mnt) { + /* more bits in this fsn_mark than the object's mask? */ + do_object = (new_mask & ~mnt->mnt_fsnotify_mask); + /* update the object with this new fsn_mark */ + if (dropped || do_object) + fsnotify_recalc_vfsmount_mask(mnt); + } else { + BUG(); + } + + /* update the group mask with the new mask */ + if (dropped || do_group) + fsnotify_recalc_group_mask(group); + } +} + +static int fanotify_remove_mark(struct fsnotify_group *group, struct inode *inode, + struct vfsmount *mnt, unsigned int flags, __u32 mask) +{ + struct fsnotify_mark *fsn_mark = NULL; + + BUG_ON(inode && mnt); + BUG_ON(!inode && !mnt); + + if (inode) + fsn_mark = fsnotify_find_inode_mark(group, inode); + else if (mnt) + fsn_mark = fsnotify_find_vfsmount_mark(group, mnt); else - fsnotify_recalc_inode_mask(inode); + BUG(); - fsnotify_recalc_group_mask(group); + if (!fsn_mark) + return -ENOENT; + + fanotify_update_object_mask(group, inode, mnt, fsn_mark, flags, mask); /* matches the fsnotify_find_inode_mark() */ fsnotify_put_mark(fsn_mark); @@ -327,22 +379,48 @@ static int fanotify_remove_mark(struct fsnotify_group *group, return 0; } -static int fanotify_add_mark(struct fsnotify_group *group, - struct inode *inode, - __u32 mask) +static struct fsnotify_mark *fanotify_add_vfsmount_mark(struct fsnotify_group *group, + struct vfsmount *mnt) { struct fsnotify_mark *fsn_mark; - __u32 old_mask, new_mask; - int ret; - pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, - group, inode, mask); + fsn_mark = fsnotify_find_vfsmount_mark(group, mnt); + if (!fsn_mark) { + struct fsnotify_mark *new_fsn_mark; + int ret; + + fsn_mark = ERR_PTR(-ENOMEM); + new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL); + if (!new_fsn_mark) + goto out; + + fsnotify_init_mark(new_fsn_mark, fanotify_free_mark); + ret = fsnotify_add_mark(new_fsn_mark, group, NULL, mnt, 0); + if (ret) { + fsn_mark = ERR_PTR(ret); + fanotify_free_mark(new_fsn_mark); + goto out; + } + + fsn_mark = new_fsn_mark; + } +out: + return fsn_mark; +} + +static struct fsnotify_mark *fanotify_add_inode_mark(struct fsnotify_group *group, + struct inode *inode) +{ + struct fsnotify_mark *fsn_mark; + + pr_debug("%s: group=%p inode=%p\n", __func__, group, inode); fsn_mark = fsnotify_find_inode_mark(group, inode); if (!fsn_mark) { struct fsnotify_mark *new_fsn_mark; + int ret; - ret = -ENOMEM; + fsn_mark = ERR_PTR(-ENOMEM); new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL); if (!new_fsn_mark) goto out; @@ -350,57 +428,60 @@ static int fanotify_add_mark(struct fsnotify_group *group, fsnotify_init_mark(new_fsn_mark, fanotify_free_mark); ret = fsnotify_add_mark(new_fsn_mark, group, inode, NULL, 0); if (ret) { + fsn_mark = ERR_PTR(ret); fanotify_free_mark(new_fsn_mark); goto out; } fsn_mark = new_fsn_mark; } +out: + return fsn_mark; +} - ret = 0; +static int fanotify_add_mark(struct fsnotify_group *group, struct inode *inode, + struct vfsmount *mnt, unsigned int flags, __u32 mask) +{ + struct fsnotify_mark *fsn_mark; - spin_lock(&fsn_mark->lock); - old_mask = fsn_mark->mask; - fsn_mark->mask |= mask; - new_mask = fsn_mark->mask; - spin_unlock(&fsn_mark->lock); + pr_debug("%s: group=%p inode=%p mnt=%p flags=%x mask=%x\n", + __func__, group, inode, mnt, flags, mask); - /* we made changes to a mask, update the group mask and the inode mask - * so things happen quickly. */ - if (old_mask != new_mask) { - /* more bits in old than in new? */ - int dropped = (old_mask & ~new_mask); - /* more bits in this mark than the inode's mask? */ - int do_inode = (new_mask & ~inode->i_fsnotify_mask); - /* more bits in this mark than the group? */ - int do_group = (new_mask & ~group->mask); + BUG_ON(inode && mnt); + BUG_ON(!inode && !mnt); - /* update the inode with this new mark */ - if (dropped || do_inode) - fsnotify_recalc_inode_mask(inode); + if (inode) + fsn_mark = fanotify_add_inode_mark(group, inode); + else if (mnt) + fsn_mark = fanotify_add_vfsmount_mark(group, mnt); + else + BUG(); - /* update the group mask with the new mask */ - if (dropped || do_group) - fsnotify_recalc_group_mask(group); - } + if (IS_ERR(fsn_mark)) + goto out; + + fanotify_update_object_mask(group, inode, mnt, fsn_mark, flags, mask); /* match the init or the find.... */ fsnotify_put_mark(fsn_mark); out: - return ret; + return PTR_ERR(fsn_mark); } static int fanotify_update_mark(struct fsnotify_group *group, - struct inode *inode, int flags, - __u32 mask) + struct inode *inode, struct vfsmount *mnt, + int flags, __u32 mask) { - pr_debug("%s: group=%p inode=%p flags=%x mask=%x\n", __func__, - group, inode, flags, mask); + pr_debug("%s: group=%p inode=%p mnt=%p flags=%x mask=%x\n", + __func__, group, inode, mnt, flags, mask); + + BUG_ON(inode && mnt); + BUG_ON(!inode && !mnt); if (flags & FAN_MARK_ADD) - fanotify_add_mark(group, inode, mask); + fanotify_add_mark(group, inode, mnt, flags, mask); else if (flags & FAN_MARK_REMOVE) - fanotify_remove_mark(group, inode, mask); + fanotify_remove_mark(group, inode, mnt, flags, mask); else BUG(); @@ -502,7 +583,7 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags, group = filp->private_data; /* create/update an inode mark */ - ret = fanotify_update_mark(group, inode, flags, mask); + ret = fanotify_update_mark(group, inode, NULL, flags, mask); path_put(&path); fput_and_out: |