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From: "Eric W. Biederman" <ebiederm@xmission.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: <linux-kernel@vger.kernel.org>, <linux-pci@vger.kernel.org>,
	<linux-mm@kvack.org>, <linux-fsdevel@vger.kernel.org>,
	Hugh Dickins <hugh@veritas.com>, Tejun Heo <tj@kernel.org>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Greg Kroah-Hartman <gregkh@suse.de>,
	Nick Piggin <npiggin@suse.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Christoph Hellwig <hch@infradead.org>,
	"Eric W. Biederman" <ebiederm@maxwell.arastra.com>,
	"Eric W. Biederman" <ebiederm@aristanetworks.com>
Subject: [PATCH 09/23] vfs: Teach poll and select to use file_hotplug_lock
Date: Mon,  1 Jun 2009 14:50:34 -0700
Message-ID: <1243893048-17031-9-git-send-email-ebiederm@xmission.com> (raw)
In-Reply-To: <m1oct739xu.fsf@fess.ebiederm.org>

From: Eric W. Biederman <ebiederm@maxwell.arastra.com>

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.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


  parent reply index

Thread overview: 99+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-11 12:01 [RFC][PATCH 0/9] File descriptor hot-unplug support Eric W. Biederman
2009-04-11 12:03 ` [RFC][PATCH 1/9] mm: Introduce remap_file_mappings Eric W. Biederman
2009-04-11 12:05 ` [RFC][PATCH 2/9] mm: Implement generic support for revoking a mapping Eric W. Biederman
2009-04-11 12:06 ` [RFC][PATCH 3/9] sysfs: Use remap_file_mappings Eric W. Biederman
2009-04-11 12:07 ` [RFC][PATCH 4/9] vfs: Generalize the file_list Eric W. Biederman
2009-04-11 12:08 ` [RFC][PATCH 5/9] vfs: Introduce basic infrastructure for revoking a file Eric W. Biederman
2009-04-14 22:12   ` Jonathan Corbet
2009-04-15  2:55     ` Eric W. Biederman
2009-04-11 12:10 ` [RFC][PATCH 6/9] vfs: Utilize fops_read_lock where appropriate Eric W. Biederman
2009-04-11 12:11 ` [RFC][PATCH 7/9] vfs: Optimize fops_read_lock Eric W. Biederman
2009-04-11 12:13 ` [RFC][PATCH 8/9] vfs: Implement generic revoked file operations Eric W. Biederman
2009-04-12 18:56   ` Jamie Lokier
2009-04-12 20:04     ` Eric W. Biederman
2009-04-12 20:31       ` Jamie Lokier
2009-04-12 21:53         ` Eric W. Biederman
2009-04-12 20:54       ` Eric W. Biederman
2009-04-12 21:02         ` Jamie Lokier
2009-04-12 23:06           ` Eric W. Biederman
2009-04-11 12:14 ` [RFC][PATCH 9/9] proc: Use the generic vfs revoke facility that now exists Eric W. Biederman
2009-04-11 15:58 ` [RFC][PATCH 0/9] File descriptor hot-unplug support Al Viro
2009-04-11 16:49   ` Eric W. Biederman
2009-04-11 16:56     ` Al Viro
2009-04-11 23:57       ` Eric W. Biederman
2009-04-12 20:21       ` Eric W. Biederman
2009-04-14  3:16 ` Tejun Heo
2009-04-14  7:39   ` Eric W. Biederman
2009-04-14  7:45     ` Tejun Heo
2009-04-14  8:27       ` Eric W. Biederman
2009-04-14  8:49         ` Tejun Heo
2009-04-14 15:07         ` Jamie Lokier
2009-04-14 19:09           ` Eric W. Biederman
2009-06-01 21:45 ` [PATCH 0/23] File descriptor hot-unplug support v2 Eric W. Biederman
2009-06-01 21:50   ` [PATCH 01/23] mm: Introduce revoke_file_mappings Eric W. Biederman
2009-06-01 22:25     ` Andrew Morton
2009-06-02  0:12       ` Eric W. Biederman
2009-06-01 21:50   ` [PATCH 02/23] vfs: Implement unpoll_file Eric W. Biederman
2009-06-06  8:08     ` Al Viro
2009-06-01 21:50   ` [PATCH 03/23] vfs: Generalize the file_list Eric W. Biederman
2009-06-02  7:06     ` Nick Piggin
2009-06-05 19:33       ` Eric W. Biederman
2009-06-09 10:38         ` Nick Piggin
2009-06-09 18:38           ` Eric W. Biederman
2009-06-10  6:05             ` Nick Piggin
2009-06-01 21:50   ` [PATCH 04/23] vfs: Introduce infrastructure for revoking a file Eric W. Biederman
2009-06-02  5:16     ` Pekka Enberg
2009-06-02  6:51       ` Eric W. Biederman
2009-06-02  7:08         ` Pekka Enberg
2009-06-02  7:14     ` Nick Piggin
2009-06-02 17:06       ` Linus Torvalds
2009-06-02 20:52         ` Eric W. Biederman
2009-06-03  6:37           ` Nick Piggin
2009-06-02 22:56       ` Eric W. Biederman
2009-06-03  6:38         ` Nick Piggin
2009-06-05  9:03     ` Miklos Szeredi
2009-06-05 19:06       ` Eric W. Biederman
2009-06-01 21:50   ` [PATCH 05/23] vfs: Teach lseek to use file_hotplug_lock Eric W. Biederman
2009-06-01 21:50   ` [PATCH 06/23] vfs: Teach read/write to use file_hotplug_read_lock Eric W. Biederman
2009-06-01 21:50   ` [PATCH 07/23] vfs: Teach sendfile,splice,tee,and vmsplice to use file_hotplug_lock Eric W. Biederman
2009-06-03 23:39     ` Badari Pulavarty
2009-06-05 19:37       ` Eric W. Biederman
2009-06-01 21:50   ` [PATCH 08/23] vfs: Teach readdir " Eric W. Biederman
2009-06-01 21:50   ` Eric W. Biederman [this message]
2009-06-01 21:50   ` [PATCH 10/23] vfs: Teach do_path_lookup " Eric W. Biederman
2009-06-01 21:50   ` [PATCH 11/23] mm: Teach mmap " Eric W. Biederman
2009-06-01 21:50   ` [PATCH 12/23] vfs: Teach fcntl " Eric W. Biederman
2009-06-01 21:50   ` [PATCH 13/23] vfs: Teach ioctl " Eric W. Biederman
2009-06-01 21:50   ` [PATCH 14/23] vfs: Teach flock " Eric W. Biederman
2009-06-01 21:50   ` [PATCH 15/23] vfs: Teach fallocate, and filp_close " Eric W. Biederman
2009-06-01 21:50   ` [PATCH 16/23] vfs: Teach fstatfs, fstatfs64, ftruncate, fchdir, fchmod, fchown " Eric W. Biederman
2009-06-01 21:50   ` [PATCH 17/23] proc: Teach /proc/<pid>/fd " Eric W. Biederman
2009-06-01 21:50   ` [PATCH 18/23] vfs: Teach epoll " Eric W. Biederman
2009-06-02 16:51     ` Davide Libenzi
2009-06-02 21:23       ` Eric W. Biederman
2009-06-02 21:52         ` Davide Libenzi
2009-06-02 22:51           ` Eric W. Biederman
2009-06-03 14:57             ` Davide Libenzi
2009-06-03 20:53               ` Eric W. Biederman
2009-06-04  0:50                 ` Davide Libenzi
2009-06-04  1:42                   ` Eric W. Biederman
2009-06-01 21:50   ` [PATCH 19/23] eventpoll: Fix comment Eric W. Biederman
2009-06-01 21:50   ` [PATCH 20/23] vfs: Teach aio to use file_hotplug_lock Eric W. Biederman
2009-06-01 21:50   ` [PATCH 21/23] vfs: Teach fsync " Eric W. Biederman
2009-06-01 21:50   ` [PATCH 22/23] vfs: Teach fadvice to file_hotplug_lock Eric W. Biederman
2009-06-01 21:50   ` [PATCH 23/23] vfs: Teach readahead to use the file_hotplug_lock Eric W. Biederman
2009-06-03 23:25     ` Badari Pulavarty
2009-06-06  8:03   ` [PATCH 0/23] File descriptor hot-unplug support v2 Al Viro
2009-06-08  9:41     ` Miklos Szeredi
2009-06-08 10:24       ` Jamie Lokier
2009-06-08 16:29       ` Al Viro
2009-06-08 16:44         ` Miklos Szeredi
2009-06-08 17:50           ` Al Viro
2009-06-08 18:01             ` Linus Torvalds
2009-06-08 18:50               ` Al Viro
2009-06-08 19:18                 ` Linus Torvalds
2009-06-09  6:42                   ` Eric W. Biederman
2009-06-09 10:52                     ` Nick Piggin
2009-06-09  5:50             ` Miklos Szeredi
2009-06-09  6:31               ` Eric W. Biederman
2009-06-09  6:22     ` Eric W. Biederman

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