[PATCH] POLLRDHUP/EPOLLRDHUP handling for half-closed devices notifications

Implement 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.

There is "a stupid program" to test POLLRDHUP delivery here:

 http://www.xmailserver.org/pollrdhup-test.c

It tests poll(2), but since the delivery is same epoll(2) will work equally.

Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

21 files changed, 22 insertions, 0 deletions

diff --git a/include/asm-alpha/poll.h b/include/asm-alpha/poll.h
index 34f333b..9570718 100644
--- a/include/asm-alpha/poll.h
+++ b/include/asm-alpha/poll.h
@@ -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 --git a/include/asm-arm/poll.h b/include/asm-arm/poll.h
index 2744ca8..5030b2b 100644
--- a/include/asm-arm/poll.h
+++ b/include/asm-arm/poll.h
@@ -16,6 +16,7 @@
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-arm26/poll.h b/include/asm-arm26/poll.h
index fdfdab0..9ccb7f4 100644
--- a/include/asm-arm26/poll.h
+++ b/include/asm-arm26/poll.h
@@ -15,6 +15,7 @@
 #define POLLWRNORM	0x0100
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-cris/poll.h b/include/asm-cris/poll.h
index 1c0efc3..1b25d4c 100644
--- a/include/asm-cris/poll.h
+++ b/include/asm-cris/poll.h
@@ -15,6 +15,7 @@
 #define POLLWRBAND	512
 #define POLLMSG		1024
 #define POLLREMOVE	4096
+#define POLLRDHUP       8192
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-frv/poll.h b/include/asm-frv/poll.h
index 8cbcd60..c8fe880 100644
--- a/include/asm-frv/poll.h
+++ b/include/asm-frv/poll.h
@@ -12,6 +12,7 @@
 #define POLLRDBAND	128
 #define POLLWRBAND	256
 #define POLLMSG		0x0400
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-h8300/poll.h b/include/asm-h8300/poll.h
index bf49ab8..fc52103 100644
--- a/include/asm-h8300/poll.h
+++ b/include/asm-h8300/poll.h
@@ -12,6 +12,7 @@
 #define POLLRDBAND	128
 #define POLLWRBAND	256
 #define POLLMSG		0x0400
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-i386/poll.h b/include/asm-i386/poll.h
index aecc80a..2cd4929 100644
--- a/include/asm-i386/poll.h
+++ b/include/asm-i386/poll.h
@@ -16,6 +16,7 @@
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-ia64/poll.h b/include/asm-ia64/poll.h
index 160258a..bcaf9f1 100644
--- a/include/asm-ia64/poll.h
+++ b/include/asm-ia64/poll.h
@@ -21,6 +21,7 @@
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-m32r/poll.h b/include/asm-m32r/poll.h
index 43b7acf..9e0e700 100644
--- a/include/asm-m32r/poll.h
+++ b/include/asm-m32r/poll.h
@@ -21,6 +21,7 @@
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-m68k/poll.h b/include/asm-m68k/poll.h
index c4b69c4..0fb8843 100644
--- a/include/asm-m68k/poll.h
+++ b/include/asm-m68k/poll.h
@@ -13,6 +13,7 @@
 #define POLLWRBAND	256
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-mips/poll.h b/include/asm-mips/poll.h
index a000f1f..70881f8 100644
--- a/include/asm-mips/poll.h
+++ b/include/asm-mips/poll.h
@@ -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 --git a/include/asm-parisc/poll.h b/include/asm-parisc/poll.h
index 1c1da86..20e4d03 100644
--- a/include/asm-parisc/poll.h
+++ b/include/asm-parisc/poll.h
@@ -16,6 +16,7 @@
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-powerpc/poll.h b/include/asm-powerpc/poll.h
index edd2054..9c7d126 100644
--- a/include/asm-powerpc/poll.h
+++ b/include/asm-powerpc/poll.h
@@ -13,6 +13,7 @@
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-s390/poll.h b/include/asm-s390/poll.h
index e90a5ca..6f7f65a 100644
--- a/include/asm-s390/poll.h
+++ b/include/asm-s390/poll.h
@@ -24,6 +24,7 @@
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-sh/poll.h b/include/asm-sh/poll.h
index 52f95b9..dbca9b3 100644
--- a/include/asm-sh/poll.h
+++ b/include/asm-sh/poll.h
@@ -16,6 +16,7 @@
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-sh64/poll.h b/include/asm-sh64/poll.h
index a420d14..3a6cbad 100644
--- a/include/asm-sh64/poll.h
+++ b/include/asm-sh64/poll.h
@@ -26,6 +26,7 @@
 #define POLLWRNORM	0x0100
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-sparc/poll.h b/include/asm-sparc/poll.h
index 3ddcc64..26f13fb 100644
--- a/include/asm-sparc/poll.h
+++ b/include/asm-sparc/poll.h
@@ -13,6 +13,7 @@
 #define POLLWRBAND	256
 #define POLLMSG		512
 #define POLLREMOVE	1024
+#define POLLRDHUP       2048
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-sparc64/poll.h b/include/asm-sparc64/poll.h
index 31b611a..ab6b0d1 100644
--- a/include/asm-sparc64/poll.h
+++ b/include/asm-sparc64/poll.h
@@ -13,6 +13,7 @@
 #define POLLWRBAND	256
 #define POLLMSG		512
 #define POLLREMOVE	1024
+#define POLLRDHUP       2048
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-v850/poll.h b/include/asm-v850/poll.h
index 0369562..c10176c 100644
--- a/include/asm-v850/poll.h
+++ b/include/asm-v850/poll.h
@@ -13,6 +13,7 @@
 #define POLLWRBAND	0x0100
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-x86_64/poll.h b/include/asm-x86_64/poll.h
index c43cbba..c0475a9 100644
--- a/include/asm-x86_64/poll.h
+++ b/include/asm-x86_64/poll.h
@@ -16,6 +16,7 @@
 #define POLLWRBAND	0x0200
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x1000
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;
diff --git a/include/asm-xtensa/poll.h b/include/asm-xtensa/poll.h
index dffe447..6fd9477 100644
--- a/include/asm-xtensa/poll.h
+++ b/include/asm-xtensa/poll.h
@@ -27,6 +27,7 @@
 
 #define POLLMSG		0x0400
 #define POLLREMOVE	0x0800
+#define POLLRDHUP       0x2000
 
 struct pollfd {
 	int fd;