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authorEric Paris <eparis@redhat.com>2009-12-18 05:24:25 +0300
committerEric Paris <eparis@redhat.com>2010-07-28 17:58:54 +0400
commitecf081d1a73b077916f514f2ec744ded32b88ca1 (patch)
treef1a9892131a297d0f67cb0fd9189e3aac83e2219 /include/linux/fsnotify.h
parent35566087099c3ff8901d65ee98af56347ee66e5a (diff)
downloadlinux-ecf081d1a73b077916f514f2ec744ded32b88ca1.tar.xz
vfs: introduce FMODE_NONOTIFY
This is a new f_mode which can only be set by the kernel. It indicates that the fd was opened by fanotify and should not cause future fanotify events. This is needed to prevent fanotify livelock. An example of obvious livelock is from fanotify close events. Process A closes file1 This creates a close event for file1. fanotify opens file1 for Listener X Listener X deals with the event and closes its fd for file1. This creates a close event for file1. fanotify opens file1 for Listener X Listener X deals with the event and closes its fd for file1. This creates a close event for file1. fanotify opens file1 for Listener X Listener X deals with the event and closes its fd for file1. notice a pattern? The fix is to add the FMODE_NONOTIFY bit to the open filp done by the kernel for fanotify. Thus when that file is used it will not generate future events. This patch simply defines the bit. Signed-off-by: Eric Paris <eparis@redhat.com>
Diffstat (limited to 'include/linux/fsnotify.h')
-rw-r--r--include/linux/fsnotify.h24
1 files changed, 16 insertions, 8 deletions
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index 62e93a9dd115..5184a2b786c1 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -165,8 +165,10 @@ static inline void fsnotify_access(struct file *file)
if (S_ISDIR(inode->i_mode))
mask |= FS_IN_ISDIR;
- fsnotify_parent(path, NULL, mask);
- fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+ if (!(file->f_mode & FMODE_NONOTIFY)) {
+ fsnotify_parent(path, NULL, mask);
+ fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+ }
}
/*
@@ -181,8 +183,10 @@ static inline void fsnotify_modify(struct file *file)
if (S_ISDIR(inode->i_mode))
mask |= FS_IN_ISDIR;
- fsnotify_parent(path, NULL, mask);
- fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+ if (!(file->f_mode & FMODE_NONOTIFY)) {
+ fsnotify_parent(path, NULL, mask);
+ fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+ }
}
/*
@@ -197,8 +201,10 @@ static inline void fsnotify_open(struct file *file)
if (S_ISDIR(inode->i_mode))
mask |= FS_IN_ISDIR;
- fsnotify_parent(path, NULL, mask);
- fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+ if (!(file->f_mode & FMODE_NONOTIFY)) {
+ fsnotify_parent(path, NULL, mask);
+ fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+ }
}
/*
@@ -214,8 +220,10 @@ static inline void fsnotify_close(struct file *file)
if (S_ISDIR(inode->i_mode))
mask |= FS_IN_ISDIR;
- fsnotify_parent(path, NULL, mask);
- fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+ if (!(file->f_mode & FMODE_NONOTIFY)) {
+ fsnotify_parent(path, NULL, mask);
+ fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
+ }
}
/*