From d9a6f30bb89309a7f2473028a00b83b020049cb4 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Fri, 20 Apr 2018 16:10:51 -0700 Subject: fsnotify: introduce marks iteration helpers Introduce helpers fsnotify_iter_select_report_types() and fsnotify_iter_next() to abstract the inode/vfsmount marks merged list iteration. This is a preparation patch before generalizing mark list iteration to more mark object types (i.e. super block marks). Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara --- fs/notify/fsnotify.c | 74 ++++++++++++++++++++++++++++++++++------------------ 1 file changed, 49 insertions(+), 25 deletions(-) (limited to 'fs') diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 9a63cf07f858..98e91037b11d 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -260,6 +260,53 @@ static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark) return hlist_entry_safe(node, struct fsnotify_mark, obj_list); } +/* + * iter_info is a multi head priority queue of marks. + * Pick a subset of marks from queue heads, all with the + * same group and set the report_mask for selected subset. + * Returns the report_mask of the selected subset. + */ +static unsigned int fsnotify_iter_select_report_types( + struct fsnotify_iter_info *iter_info) +{ + struct fsnotify_mark *inode_mark = iter_info->inode_mark; + struct fsnotify_mark *vfsmount_mark = iter_info->vfsmount_mark; + int cmp; + + if (!inode_mark && !vfsmount_mark) + return 0; + + if (inode_mark && vfsmount_mark) { + cmp = fsnotify_compare_groups(inode_mark->group, + vfsmount_mark->group); + } else { + cmp = inode_mark ? -1 : 1; + } + + iter_info->report_mask = 0; + if (cmp <= 0) + iter_info->report_mask |= FSNOTIFY_OBJ_TYPE_INODE_FL; + if (cmp >= 0) + iter_info->report_mask |= FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL; + + return iter_info->report_mask; +} + +/* + * Pop from iter_info multi head queue, the marks that were iterated in the + * current iteration step. + */ +static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info) +{ + if (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_INODE_FL) + iter_info->inode_mark = + fsnotify_next_mark(iter_info->inode_mark); + + if (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL) + iter_info->vfsmount_mark = + fsnotify_next_mark(iter_info->vfsmount_mark); +} + /* * This is the main call to fsnotify. The VFS calls into hook specific functions * in linux/fsnotify.h. Those functions then in turn call here. Here will call @@ -321,37 +368,14 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, * ignore masks are properly reflected for mount mark notifications. * That's why this traversal is so complicated... */ - while (iter_info.inode_mark || iter_info.vfsmount_mark) { - struct fsnotify_mark *inode_mark = iter_info.inode_mark; - struct fsnotify_mark *vfsmount_mark = iter_info.vfsmount_mark; - int cmp; - - if (inode_mark && vfsmount_mark) { - cmp = fsnotify_compare_groups(inode_mark->group, - vfsmount_mark->group); - } else { - cmp = inode_mark ? -1 : 1; - } - - iter_info.report_mask = 0; - if (cmp <= 0) - iter_info.report_mask |= FSNOTIFY_OBJ_TYPE_INODE_FL; - if (cmp >= 0) - iter_info.report_mask |= FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL; - + while (fsnotify_iter_select_report_types(&iter_info)) { ret = send_to_group(to_tell, mask, data, data_is, cookie, file_name, &iter_info); if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS)) goto out; - if (iter_info.report_mask & FSNOTIFY_OBJ_TYPE_INODE_FL) - iter_info.inode_mark = - fsnotify_next_mark(iter_info.inode_mark); - - if (iter_info.report_mask & FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL) - iter_info.vfsmount_mark = - fsnotify_next_mark(iter_info.vfsmount_mark); + fsnotify_iter_next(&iter_info); } ret = 0; out: -- cgit v1.2.1