Message ID | 1450443589-23775-1-git-send-email-tim.gardner@canonical.com |
---|---|
State | New |
Headers | show |
On Fri, 2015-12-18 at 05:59 -0700, tim.gardner@canonical.com wrote: > From: Will Woods <wwoods@redhat.com> > > BugLink: http://bugs.launchpad.net/bugs/1527039 > > On 64-bit systems, O_LARGEFILE is automatically added to flags inside > the open() syscall (also openat(), blkdev_open(), etc). Userspace > therefore defines O_LARGEFILE to be 0 - you can use it, but it's a > no-op. Everything should be O_LARGEFILE by default. > > But: when fanotify does create_fd() it uses dentry_open(), which skips > all that. And userspace can't set O_LARGEFILE in fanotify_init() > because it's defined to 0. So if fanotify gets an event regarding a > large file, the read() will just fail with -EOVERFLOW. > > This patch adds O_LARGEFILE to fanotify_init()'s event_f_flags on 64-bit > systems, using the same test as open()/openat()/etc. > > Addresses https://bugzilla.redhat.com/show_bug.cgi?id=696821 > > Signed-off-by: Will Woods <wwoods@redhat.com> > Acked-by: Eric Paris <eparis@redhat.com> > Reviewed-by: Jan Kara <jack@suse.cz> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > (back ported from commit 1e2ee49f7f1b79f0b14884fe6a602f0411b39552) > Signed-off-by: Tim Gardner <tim.gardner@canonical.com> > --- > fs/notify/fanotify/fanotify_user.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c > index cc80b0a..864bd62 100644 > --- a/fs/notify/fanotify/fanotify_user.c > +++ b/fs/notify/fanotify/fanotify_user.c > @@ -727,6 +727,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) > group->fanotify_data.user = user; > atomic_inc(&user->fanotify_listeners); > > + if (force_o_largefile()) > + event_f_flags |= O_LARGEFILE; > group->fanotify_data.f_flags = event_f_flags; > #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS > mutex_init(&group->fanotify_data.access_mutex); > -- > 1.9.1 > > Looks fine. -Kamal
On Fri, Dec 18, 2015 at 05:59:49AM -0700, tim.gardner@canonical.com wrote: > From: Will Woods <wwoods@redhat.com> > > BugLink: http://bugs.launchpad.net/bugs/1527039 > > On 64-bit systems, O_LARGEFILE is automatically added to flags inside > the open() syscall (also openat(), blkdev_open(), etc). Userspace > therefore defines O_LARGEFILE to be 0 - you can use it, but it's a > no-op. Everything should be O_LARGEFILE by default. > > But: when fanotify does create_fd() it uses dentry_open(), which skips > all that. And userspace can't set O_LARGEFILE in fanotify_init() > because it's defined to 0. So if fanotify gets an event regarding a > large file, the read() will just fail with -EOVERFLOW. > > This patch adds O_LARGEFILE to fanotify_init()'s event_f_flags on 64-bit > systems, using the same test as open()/openat()/etc. > > Addresses https://bugzilla.redhat.com/show_bug.cgi?id=696821 > > Signed-off-by: Will Woods <wwoods@redhat.com> > Acked-by: Eric Paris <eparis@redhat.com> > Reviewed-by: Jan Kara <jack@suse.cz> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > (back ported from commit 1e2ee49f7f1b79f0b14884fe6a602f0411b39552) > Signed-off-by: Tim Gardner <tim.gardner@canonical.com> > --- > fs/notify/fanotify/fanotify_user.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c > index cc80b0a..864bd62 100644 > --- a/fs/notify/fanotify/fanotify_user.c > +++ b/fs/notify/fanotify/fanotify_user.c > @@ -727,6 +727,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) > group->fanotify_data.user = user; > atomic_inc(&user->fanotify_listeners); > > + if (force_o_largefile()) > + event_f_flags |= O_LARGEFILE; > group->fanotify_data.f_flags = event_f_flags; > #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS > mutex_init(&group->fanotify_data.access_mutex); Looks to do what is claimed. Acked-by: Andy Whitcroft <apw@canonical.com> -apw
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index cc80b0a..864bd62 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -727,6 +727,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) group->fanotify_data.user = user; atomic_inc(&user->fanotify_listeners); + if (force_o_largefile()) + event_f_flags |= O_LARGEFILE; group->fanotify_data.f_flags = event_f_flags; #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS mutex_init(&group->fanotify_data.access_mutex);