From 84e1ab4d875922c034db7f4f814ac445a20a14bd Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Wed, 18 Aug 2010 12:25:50 -0400 Subject: [PATCH] fsnotify: fix ignored mask handling between inode and vfsmount marks The interesting 2 list lockstep walking didn't quite work out if the inode marks only had ignores and the vfsmount list requested events. The code to shortcut list traversal would not run the inode list since it didn't have real event requests. This code forces inode list traversal when a vfsmount mark matches the event type. Maybe we could add an i_fsnotify_ignored_mask field to struct inode to get the shortcut back, but it doesn't seem worth it to grow struct inode again. I bet with the recent changes to lock the way we do now it would actually not be a major perf hit to just drop i_fsnotify_mark_mask altogether. But that is for another day. Signed-off-by: Eric Paris --- fs/notify/fsnotify.c | 35 +++++++++++++++++------------------ 1 file changed, 17 insertions(+), 18 deletions(-) diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 59dc7a02bd0c..6f2777ce87a1 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -149,8 +149,8 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt, struct fsnotify_event **event) { struct fsnotify_group *group = NULL; - __u32 inode_test_mask = (mask & ~FS_EVENT_ON_CHILD); - __u32 vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD); + __u32 inode_test_mask = 0; + __u32 vfsmount_test_mask = 0; if (unlikely(!inode_mark && !vfsmount_mark)) { BUG(); @@ -170,12 +170,14 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt, /* does the inode mark tell us to do something? */ if (inode_mark) { group = inode_mark->group; + inode_test_mask = (mask & ~FS_EVENT_ON_CHILD); inode_test_mask &= inode_mark->mask; inode_test_mask &= ~inode_mark->ignored_mask; } /* does the vfsmount_mark tell us to do something? */ if (vfsmount_mark) { + vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD); group = vfsmount_mark->group; vfsmount_test_mask &= vfsmount_mark->mask; vfsmount_test_mask &= ~vfsmount_mark->ignored_mask; @@ -183,9 +185,12 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt, vfsmount_test_mask &= ~inode_mark->ignored_mask; } - pr_debug("%s: group=%p to_tell=%p mnt=%p mark=%p mask=%x data=%p" - " data_is=%d cookie=%d event=%p\n", __func__, group, to_tell, - mnt, inode_mark, mask, data, data_is, cookie, *event); + pr_debug("%s: group=%p to_tell=%p mnt=%p mask=%x inode_mark=%p" + " inode_test_mask=%x vfsmount_mark=%p vfsmount_test_mask=%x" + " data=%p data_is=%d cookie=%d event=%p\n", + __func__, group, to_tell, mnt, mask, inode_mark, + inode_test_mask, vfsmount_mark, vfsmount_test_mask, data, + data_is, cookie, *event); if (!inode_test_mask && !vfsmount_test_mask) return 0; @@ -214,7 +219,7 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt, int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const unsigned char *file_name, u32 cookie) { - struct hlist_node *inode_node, *vfsmount_node; + struct hlist_node *inode_node = NULL, *vfsmount_node = NULL; struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL; struct fsnotify_group *inode_group, *vfsmount_group; struct fsnotify_event *event = NULL; @@ -245,19 +250,13 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, (test_mask & to_tell->i_fsnotify_mask)) inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first, &fsnotify_mark_srcu); - else - inode_node = NULL; - if (mnt) { - if ((mask & FS_MODIFY) || - (test_mask & mnt->mnt_fsnotify_mask)) - vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first, - &fsnotify_mark_srcu); - else - vfsmount_node = NULL; - } else { - mnt = NULL; - vfsmount_node = NULL; + if (mnt && ((mask & FS_MODIFY) || + (test_mask & mnt->mnt_fsnotify_mask))) { + vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first, + &fsnotify_mark_srcu); + inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first, + &fsnotify_mark_srcu); } while (inode_node || vfsmount_node) { -- GitLab