fsnotify: add marks to inodes so groups can interpret how to handle those inodes

This patch creates a way for fsnotify groups to attach marks to inodes.
These marks have little meaning to the generic fsnotify infrastructure
and thus their meaning should be interpreted by the group that attached
them to the inode's list.

dnotify and inotify  will make use of these markings to indicate which
inodes are of interest to their respective groups.  But this implementation
has the useful property that in the future other listeners could actually
use the marks for the exact opposite reason, aka to indicate which inodes
it had NO interest in.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>

1 files changed, 9 insertions, 0 deletions

diff --git a/fs/inode.c b/fs/inode.c
index bca0c618fdb3..54c63ce3de25 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -22,6 +22,7 @@
 #include <linux/cdev.h>
 #include <linux/bootmem.h>
 #include <linux/inotify.h>
+#include <linux/fsnotify.h>
 #include <linux/mount.h>
 #include <linux/async.h>
 
@@ -189,6 +190,10 @@ struct inode *inode_init_always(struct super_block *sb, struct inode *inode)
         inode->i_private = NULL;
         inode->i_mapping = mapping;
 
+#ifdef CONFIG_FSNOTIFY
+        inode->i_fsnotify_mask = 0;
+#endif
+
         return inode;
 
 out_free_security:
@@ -221,6 +226,7 @@ void destroy_inode(struct inode *inode)
         BUG_ON(inode_has_buffers(inode));
         ima_inode_free(inode);
         security_inode_free(inode);
+        fsnotify_inode_delete(inode);
         if (inode->i_sb->s_op->destroy_inode)
                 inode->i_sb->s_op->destroy_inode(inode);
         else
@@ -252,6 +258,9 @@ void inode_init_once(struct inode *inode)
         INIT_LIST_HEAD(&inode->inotify_watches);
         mutex_init(&inode->inotify_mutex);
 #endif
+#ifdef CONFIG_FSNOTIFY
+        INIT_HLIST_HEAD(&inode->i_fsnotify_mark_entries);
+#endif
 }
 EXPORT_SYMBOL(inode_init_once);