[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1243893048-17031-9-git-send-email-ebiederm@xmission.com>
Date: Mon, 1 Jun 2009 14:50:34 -0700
From: "Eric W. Biederman" <ebiederm@...ssion.com>
To: Al Viro <viro@...IV.linux.org.uk>
Cc: <linux-kernel@...r.kernel.org>, <linux-pci@...r.kernel.org>,
<linux-mm@...ck.org>, <linux-fsdevel@...r.kernel.org>,
Hugh Dickins <hugh@...itas.com>, Tejun Heo <tj@...nel.org>,
Alexey Dobriyan <adobriyan@...il.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Alan Cox <alan@...rguk.ukuu.org.uk>,
Greg Kroah-Hartman <gregkh@...e.de>,
Nick Piggin <npiggin@...e.de>,
Andrew Morton <akpm@...ux-foundation.org>,
Christoph Hellwig <hch@...radead.org>,
"Eric W. Biederman" <ebiederm@...well.arastra.com>,
"Eric W. Biederman" <ebiederm@...stanetworks.com>
Subject: [PATCH 09/23] vfs: Teach poll and select to use file_hotplug_lock
From: Eric W. Biederman <ebiederm@...well.arastra.com>
Signed-off-by: Eric W. Biederman <ebiederm@...stanetworks.com>
---
fs/select.c | 24 +++++++++++++++++-------
include/linux/poll.h | 1 +
2 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/fs/select.c b/fs/select.c
index 99e4145..fd68da0 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -416,10 +416,15 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
continue;
file = fget_light(i, &fput_needed);
if (file) {
- f_op = file->f_op;
- mask = DEFAULT_POLLMASK;
- if (f_op && f_op->poll)
- mask = (*f_op->poll)(file, retval ? NULL : wait);
+ mask = DEAD_POLLMASK;
+ if (file_hotplug_read_trylock(file)) {
+ f_op = file->f_op;
+ mask = DEFAULT_POLLMASK;
+ if (f_op && f_op->poll)
+ mask = (*f_op->poll)(file, retval ? NULL : wait);
+
+ file_hotplug_read_unlock(file);
+ }
fput_light(file, fput_needed);
if ((mask & POLLIN_SET) && (in & bit)) {
res_in |= bit;
@@ -684,9 +689,14 @@ static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait)
file = fget_light(fd, &fput_needed);
mask = POLLNVAL;
if (file != NULL) {
- mask = DEFAULT_POLLMASK;
- if (file->f_op && file->f_op->poll)
- mask = file->f_op->poll(file, pwait);
+ mask = DEAD_POLLMASK;
+ if (file_hotplug_read_trylock(file)) {
+ mask = DEFAULT_POLLMASK;
+ if (file->f_op && file->f_op->poll)
+ mask = file->f_op->poll(file, pwait);
+
+ file_hotplug_read_unlock(file);
+ }
/* Mask out unneeded events. */
mask &= pollfd->events | POLLERR | POLLHUP;
fput_light(file, fput_needed);
diff --git a/include/linux/poll.h b/include/linux/poll.h
index d388620..f0512f4 100644
--- a/include/linux/poll.h
+++ b/include/linux/poll.h
@@ -22,6 +22,7 @@
#define N_INLINE_POLL_ENTRIES (WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry))
#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
+#define DEAD_POLLMASK (DEFAULT_POLLMASK | POLLERR)
struct poll_table_struct;
--
1.6.3.1.54.g99dd.dirty
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists