Re: fanotify: fix support of large files

From: Heinrich Schuchardt
Date: Sat Apr 13 2013 - 07:55:11 EST

Dear Justin,

looking at the example at
the large file support is enabled by passing O_LARGEFILE to fanotify_init:

if ((fanotify_fd = fanotify_init (FAN_CLOEXEC,

Could you, please, check if this solves your issue.

(I am resending this message because HTML was rejected by

Best regards

Heinrich Schuchardt

On 14.02.2013 18:29, Justin Maggard wrote:
Opening a file of>2GB in an area of the filesystem that has been marked for
fanotify events currently results in an EOVERFLOW error. This is particularly
problematic if you are using fanotify permissions checking, because it prevents
large files from being opened at all. Fix this by setting the O_LARGEFILE flag
on the new file handle.

Signed-off-by: Justin Maggard<jmaggard10@xxxxxxxxx>

fs/notify/fanotify/fanotify_user.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 9ff4a5e..ef02b3d 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -64,6 +64,7 @@ static int create_fd(struct fsnotify_group *group,
struct file **file)
int client_fd;
+ int f_flags;
struct file *new_file;

pr_debug("%s: group=%p event=%p\n", __func__, group, event);
@@ -82,12 +83,11 @@ static int create_fd(struct fsnotify_group *group,
* we need a new file handle for the userspace program so it can read even if it was
* originally opened O_WRONLY.
+ f_flags = group->fanotify_data.f_flags | FMODE_NONOTIFY | O_LARGEFILE;
/* it's possible this event was an overflow event. in that case dentry and mnt
* are NULL; That's fine, just don't call dentry open */
if (event->path.dentry&& event->path.mnt)
- new_file = dentry_open(&event->path,
- group->fanotify_data.f_flags | FMODE_NONOTIFY,
- current_cred());
+ new_file = dentry_open(&event->path, f_flags, current_cred());
new_file = ERR_PTR(-EOVERFLOW);
if (IS_ERR(new_file)) {

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