[patch] POLLRDHUP/EPOLLRDHUP handling for half-closed devicesnotifications ...

From: Davide Libenzi
Date: Tue Mar 07 2006 - 16:28:24 EST

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The attached patch against 2.6.16-rc5 implements the half-closed devices notifiation, by adding a new POLLRDHUP (and its alias EPOLLRDHUP) bit to the existing poll/select sets. Since the existing POLLHUP handling, that does not report correctly half-closed devices, was feared to be changed, this implementation leaves the current POLLHUP reporting unchanged and simply add a new bit that is set in the few places where it makes sense.
The same thing was discussed and conceptually agreed quite some time ago:

http://lkml.org/lkml/2003/7/12/116

Since this new event bit is added to the existing Linux poll infrastruture, even the existing poll/select system calls will be able to use it. As far as the existing POLLHUP handling, the patch leaves it as is.
The pollrdhup-2.6.16.rc5-0.10.diff defines the POLLRDHUP for all the existing archs and sets the bit in the six relevant files.
The other attached diff is the simple change required to sys/epoll.h to add the EPOLLRDHUP definition.

Signed-off-by: Davide Libenzi <davidel@xxxxxxxxxxxxxxx>

- Davide

fs/eventpoll.c | 4 ++--
include/asm-alpha/poll.h | 2 ++
include/asm-arm/poll.h | 1 +
include/asm-arm26/poll.h | 1 +
include/asm-cris/poll.h | 1 +
include/asm-frv/poll.h | 1 +
include/asm-h8300/poll.h | 1 +
include/asm-i386/poll.h | 1 +
include/asm-ia64/poll.h | 1 +
include/asm-m32r/poll.h | 1 +
include/asm-m68k/poll.h | 1 +
include/asm-mips/poll.h | 1 +
include/asm-parisc/poll.h | 1 +
include/asm-powerpc/poll.h | 1 +
include/asm-s390/poll.h | 1 +
include/asm-sh/poll.h | 1 +
include/asm-sh64/poll.h | 1 +
include/asm-sparc/poll.h | 1 +
include/asm-sparc64/poll.h | 1 +
include/asm-v850/poll.h | 1 +
include/asm-x86_64/poll.h | 1 +
include/asm-xtensa/poll.h | 1 +
net/bluetooth/af_bluetooth.c | 3 +++
net/core/datagram.c | 2 ++
net/dccp/proto.c | 2 +-
net/ipv4/tcp.c | 2 +-
net/sctp/socket.c | 2 ++
net/unix/af_unix.c | 2 ++
28 files changed, 35 insertions(+), 4 deletions(-)
diff -Nru linux-2.6.15/fs/eventpoll.c linux-2.6.15.mod/fs/eventpoll.c
--- linux-2.6.15/fs/eventpoll.c 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/fs/eventpoll.c 2006-03-07 12:25:08.000000000 -0800
@@ -607,7 +607,7 @@
switch (op) {
case EPOLL_CTL_ADD:
if (!epi) {
- epds.events |= POLLERR | POLLHUP;
+ epds.events |= POLLERR | POLLHUP | POLLRDHUP;

error = ep_insert(ep, &epds, tfile, fd);
} else
@@ -621,7 +621,7 @@
break;
case EPOLL_CTL_MOD:
if (epi) {
- epds.events |= POLLERR | POLLHUP;
+ epds.events |= POLLERR | POLLHUP | POLLRDHUP;
error = ep_modify(ep, epi, &epds);
} else
error = -ENOENT;
diff -Nru linux-2.6.15/include/asm-alpha/poll.h linux-2.6.15.mod/include/asm-alpha/poll.h
--- linux-2.6.15/include/asm-alpha/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-alpha/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -13,6 +13,8 @@
#define POLLWRBAND (1 << 9)
#define POLLMSG (1 << 10)
#define POLLREMOVE (1 << 11)
+#define POLLRDHUP (1 << 12)
+

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-arm/poll.h linux-2.6.15.mod/include/asm-arm/poll.h
--- linux-2.6.15/include/asm-arm/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-arm/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -16,6 +16,7 @@
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-arm26/poll.h linux-2.6.15.mod/include/asm-arm26/poll.h
--- linux-2.6.15/include/asm-arm26/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-arm26/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -15,6 +15,7 @@
#define POLLWRNORM 0x0100
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-cris/poll.h linux-2.6.15.mod/include/asm-cris/poll.h
--- linux-2.6.15/include/asm-cris/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-cris/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -15,6 +15,7 @@
#define POLLWRBAND 512
#define POLLMSG 1024
#define POLLREMOVE 4096
+#define POLLRDHUP 8192

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-frv/poll.h linux-2.6.15.mod/include/asm-frv/poll.h
--- linux-2.6.15/include/asm-frv/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-frv/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -12,6 +12,7 @@
#define POLLRDBAND 128
#define POLLWRBAND 256
#define POLLMSG 0x0400
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-h8300/poll.h linux-2.6.15.mod/include/asm-h8300/poll.h
--- linux-2.6.15/include/asm-h8300/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-h8300/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -12,6 +12,7 @@
#define POLLRDBAND 128
#define POLLWRBAND 256
#define POLLMSG 0x0400
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-i386/poll.h linux-2.6.15.mod/include/asm-i386/poll.h
--- linux-2.6.15/include/asm-i386/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-i386/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -16,6 +16,7 @@
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-ia64/poll.h linux-2.6.15.mod/include/asm-ia64/poll.h
--- linux-2.6.15/include/asm-ia64/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-ia64/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -21,6 +21,7 @@
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-m32r/poll.h linux-2.6.15.mod/include/asm-m32r/poll.h
--- linux-2.6.15/include/asm-m32r/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-m32r/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -21,6 +21,7 @@
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-m68k/poll.h linux-2.6.15.mod/include/asm-m68k/poll.h
--- linux-2.6.15/include/asm-m68k/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-m68k/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -13,6 +13,7 @@
#define POLLWRBAND 256
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-mips/poll.h linux-2.6.15.mod/include/asm-mips/poll.h
--- linux-2.6.15/include/asm-mips/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-mips/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -17,6 +17,7 @@
/* These seem to be more or less nonstandard ... */
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-parisc/poll.h linux-2.6.15.mod/include/asm-parisc/poll.h
--- linux-2.6.15/include/asm-parisc/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-parisc/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -16,6 +16,7 @@
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-powerpc/poll.h linux-2.6.15.mod/include/asm-powerpc/poll.h
--- linux-2.6.15/include/asm-powerpc/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-powerpc/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -13,6 +13,7 @@
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-s390/poll.h linux-2.6.15.mod/include/asm-s390/poll.h
--- linux-2.6.15/include/asm-s390/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-s390/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -24,6 +24,7 @@
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-sh/poll.h linux-2.6.15.mod/include/asm-sh/poll.h
--- linux-2.6.15/include/asm-sh/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-sh/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -16,6 +16,7 @@
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-sh64/poll.h linux-2.6.15.mod/include/asm-sh64/poll.h
--- linux-2.6.15/include/asm-sh64/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-sh64/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -26,6 +26,7 @@
#define POLLWRNORM 0x0100
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-sparc/poll.h linux-2.6.15.mod/include/asm-sparc/poll.h
--- linux-2.6.15/include/asm-sparc/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-sparc/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -13,6 +13,7 @@
#define POLLWRBAND 256
#define POLLMSG 512
#define POLLREMOVE 1024
+#define POLLRDHUP 2048

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-sparc64/poll.h linux-2.6.15.mod/include/asm-sparc64/poll.h
--- linux-2.6.15/include/asm-sparc64/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-sparc64/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -13,6 +13,7 @@
#define POLLWRBAND 256
#define POLLMSG 512
#define POLLREMOVE 1024
+#define POLLRDHUP 2048

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-v850/poll.h linux-2.6.15.mod/include/asm-v850/poll.h
--- linux-2.6.15/include/asm-v850/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-v850/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -13,6 +13,7 @@
#define POLLWRBAND 0x0100
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-x86_64/poll.h linux-2.6.15.mod/include/asm-x86_64/poll.h
--- linux-2.6.15/include/asm-x86_64/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-x86_64/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -16,6 +16,7 @@
#define POLLWRBAND 0x0200
#define POLLMSG 0x0400
#define POLLREMOVE 0x1000
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/include/asm-xtensa/poll.h linux-2.6.15.mod/include/asm-xtensa/poll.h
--- linux-2.6.15/include/asm-xtensa/poll.h 2006-01-02 19:21:10.000000000 -0800
+++ linux-2.6.15.mod/include/asm-xtensa/poll.h 2006-03-07 12:25:08.000000000 -0800
@@ -27,6 +27,7 @@

#define POLLMSG 0x0400
#define POLLREMOVE 0x0800
+#define POLLRDHUP 0x2000

struct pollfd {
int fd;
diff -Nru linux-2.6.15/net/bluetooth/af_bluetooth.c linux-2.6.15.mod/net/bluetooth/af_bluetooth.c
--- linux-2.6.15/net/bluetooth/af_bluetooth.c 2006-03-07 12:24:26.000000000 -0800
+++ linux-2.6.15.mod/net/bluetooth/af_bluetooth.c 2006-03-07 12:25:08.000000000 -0800
@@ -238,6 +238,9 @@
if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
mask |= POLLERR;

+ if (sk->sk_shutdown & RCV_SHUTDOWN)
+ mask |= POLLRDHUP;
+
if (sk->sk_shutdown == SHUTDOWN_MASK)
mask |= POLLHUP;

diff -Nru linux-2.6.15/net/core/datagram.c linux-2.6.15.mod/net/core/datagram.c
--- linux-2.6.15/net/core/datagram.c 2006-03-07 12:24:26.000000000 -0800
+++ linux-2.6.15.mod/net/core/datagram.c 2006-03-07 12:25:08.000000000 -0800
@@ -500,6 +500,8 @@
/* exceptional events? */
if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
mask |= POLLERR;
+ if (sk->sk_shutdown & RCV_SHUTDOWN)
+ mask |= POLLRDHUP;
if (sk->sk_shutdown == SHUTDOWN_MASK)
mask |= POLLHUP;

diff -Nru linux-2.6.15/net/dccp/proto.c linux-2.6.15.mod/net/dccp/proto.c
--- linux-2.6.15/net/dccp/proto.c 2006-03-07 12:24:26.000000000 -0800
+++ linux-2.6.15.mod/net/dccp/proto.c 2006-03-07 12:25:08.000000000 -0800
@@ -183,7 +183,7 @@
if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
mask |= POLLHUP;
if (sk->sk_shutdown & RCV_SHUTDOWN)
- mask |= POLLIN | POLLRDNORM;
+ mask |= POLLIN | POLLRDNORM | POLLRDHUP;

/* Connected? */
if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
diff -Nru linux-2.6.15/net/ipv4/tcp.c linux-2.6.15.mod/net/ipv4/tcp.c
--- linux-2.6.15/net/ipv4/tcp.c 2006-03-07 12:24:26.000000000 -0800
+++ linux-2.6.15.mod/net/ipv4/tcp.c 2006-03-07 12:25:08.000000000 -0800
@@ -365,7 +365,7 @@
if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
mask |= POLLHUP;
if (sk->sk_shutdown & RCV_SHUTDOWN)
- mask |= POLLIN | POLLRDNORM;
+ mask |= POLLIN | POLLRDNORM | POLLRDHUP;

/* Connected? */
if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
diff -Nru linux-2.6.15/net/sctp/socket.c linux-2.6.15.mod/net/sctp/socket.c
--- linux-2.6.15/net/sctp/socket.c 2006-03-07 12:24:26.000000000 -0800
+++ linux-2.6.15.mod/net/sctp/socket.c 2006-03-07 12:25:08.000000000 -0800
@@ -4894,6 +4894,8 @@
/* Is there any exceptional events? */
if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
mask |= POLLERR;
+ if (sk->sk_shutdown & RCV_SHUTDOWN)
+ mask |= POLLRDHUP;
if (sk->sk_shutdown == SHUTDOWN_MASK)
mask |= POLLHUP;

diff -Nru linux-2.6.15/net/unix/af_unix.c linux-2.6.15.mod/net/unix/af_unix.c
--- linux-2.6.15/net/unix/af_unix.c 2006-03-07 12:24:26.000000000 -0800
+++ linux-2.6.15.mod/net/unix/af_unix.c 2006-03-07 12:25:08.000000000 -0800
@@ -1878,6 +1878,8 @@
mask |= POLLERR;
if (sk->sk_shutdown == SHUTDOWN_MASK)
mask |= POLLHUP;
+ if (sk->sk_shutdown & RCV_SHUTDOWN)
+ mask |= POLLRDHUP;

/* readable? */
if (!skb_queue_empty(&sk->sk_receive_queue) ||
--- epoll.h.orig 2006-03-07 12:30:57.000000000 -0800
+++ epoll.h 2006-03-07 13:25:03.000000000 -0800
@@ -45,6 +45,8 @@
#define EPOLLERR EPOLLERR
EPOLLHUP = 0x010,
#define EPOLLHUP EPOLLHUP
+ EPOLLRDHUP = 0x2000,
+#define EPOLLRDHUP EPOLLRDHUP
EPOLLONESHOT = (1 << 30),
#define EPOLLONESHOT EPOLLONESHOT
EPOLLET = (1 << 31)

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