[PATCH 1/2] notmuch-deliver: Retry with readwrite if splice() fails

[PATCH 1/2] notmuch-deliver: Retry with readwrite if splice() fails

[David Riebenbauer]

notmuch-deliver should not just fail, when splice() doesn't work. Fall
back to the readwrite method even if NOTMUCH_DELIVER_NO_SPLICE is not
set.
---
 contrib/notmuch-deliver/src/main.c |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/contrib/notmuch-deliver/src/main.c b/contrib/notmuch-deliver/src/main.c
index f7a4eaa..8423d91 100644
--- a/contrib/notmuch-deliver/src/main.c
+++ b/contrib/notmuch-deliver/src/main.c
@@ -252,9 +252,13 @@ save_maildir(int fdin, const char *dir, int auto_create, char **path)
 
 	g_debug("Reading from standard input and writing to `%s'", info.tmpname);
 #ifdef HAVE_SPLICE
-	ret = g_getenv("NOTMUCH_DELIVER_NO_SPLICE")
-		? save_readwrite(fdin, fdout)
-		: save_splice(fdin, fdout);
+	if (g_getenv("NOTMUCH_DELIVER_NO_SPLICE"))
+		ret = save_readwrite(fdin, fdout);
+	else {
+		ret = save_splice(fdin, fdout);
+		if (ret)
+			ret = save_readwrite(fdin, fdout);
+	}
 #else
 	ret = save_readwrite(fdin, fdout);
 #endif /* HAVE_SPLICE */
-- 
1.7.7.1

[PATCH 2/2] notmuch-deliver: in save_splice() log failures as debug.

[David Riebenbauer]

If we don't exit if splice fails then we should just log failures as
debug instead of critical.
---
 contrib/notmuch-deliver/src/main.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/contrib/notmuch-deliver/src/main.c b/contrib/notmuch-deliver/src/main.c
index 8423d91..39cd804 100644
--- a/contrib/notmuch-deliver/src/main.c
+++ b/contrib/notmuch-deliver/src/main.c
@@ -148,7 +148,7 @@ save_splice(int fdin, int fdout)
 	int ret, written, pfd[2];
 
 	if (pipe(pfd) < 0) {
-		g_critical("Failed to create pipe: %s", g_strerror(errno));
+		g_debug("Failed to create pipe: %s", g_strerror(errno));
 		return EX_IOERR;
 	}
 
@@ -157,7 +157,7 @@ save_splice(int fdin, int fdout)
 		if (!ret)
 			break;
 		if (ret < 0) {
-			g_critical("Splicing data from standard input failed: %s",
+			g_debug("Splicing data from standard input failed: %s",
 				g_strerror(errno));
 			close(pfd[0]);
 			close(pfd[1]);
@@ -167,13 +167,13 @@ save_splice(int fdin, int fdout)
 		do {
 			written = splice(pfd[0], NULL, fdout, NULL, ret, 0);
 			if (!written) {
-				g_critical("Splicing data to temporary file failed: internal error");
+				g_debug("Splicing data to temporary file failed: internal error");
 				close(pfd[0]);
 				close(pfd[1]);
 				return EX_IOERR;
 			}
 			if (written < 0) {
-				g_critical("Splicing data to temporary file failed: %s",
+				g_debug("Splicing data to temporary file failed: %s",
 					g_strerror(errno));
 				close(pfd[0]);
 				close(pfd[1]);
-- 
1.7.7.1

Re: [PATCH 1/2] notmuch-deliver: Retry with readwrite if splice() fails

[Ali Polatel]

Hey, David

Thanks for resending the patches!

On Sun, Nov 06, 2011 at 06:34:27AM +0100, David Riebenbauer wrote:
>notmuch-deliver should not just fail, when splice() doesn't work. Fall
>back to the readwrite method even if NOTMUCH_DELIVER_NO_SPLICE is not
>set.

This is a trivial change but I'm rather curious about the reasoning.
Did you have a problem with splice() not working?

>---
> contrib/notmuch-deliver/src/main.c |   10 +++++++---
> 1 files changed, 7 insertions(+), 3 deletions(-)
>
>diff --git a/contrib/notmuch-deliver/src/main.c b/contrib/notmuch-deliver/src/main.c
>index f7a4eaa..8423d91 100644
>--- a/contrib/notmuch-deliver/src/main.c
>+++ b/contrib/notmuch-deliver/src/main.c
>@@ -252,9 +252,13 @@ save_maildir(int fdin, const char *dir, int auto_create, char **path)
>
> 	g_debug("Reading from standard input and writing to `%s'", info.tmpname);
> #ifdef HAVE_SPLICE
>-	ret = g_getenv("NOTMUCH_DELIVER_NO_SPLICE")
>-		? save_readwrite(fdin, fdout)
>-		: save_splice(fdin, fdout);
>+	if (g_getenv("NOTMUCH_DELIVER_NO_SPLICE"))
>+		ret = save_readwrite(fdin, fdout);
>+	else {
>+		ret = save_splice(fdin, fdout);
>+		if (ret)
>+			ret = save_readwrite(fdin, fdout);
>+	}

I'm inclined to think this retry should be user configurable as well.
How about we remove NOTMUCH_DELIVER_NO_SPLICE environment variable and
add a command line flag like --save-method which may have the following
invocations:

--save-method=readwrite        calls save_readwrite()
--save-method=splice           calls save_splice()
--save-method=readwrite,splice try save_readwrite() and then splice()
--save-method=splice,readwrite try save_splice and then readwrite()

The second invocation should fail in case splice is not available. Also
adding an environment variable like NOTMUCH_DELIVER_SAVE_METHOD so
people can stick it into their dotfiles is a good idea.

Thoughts?

		-alip

> #else
> 	ret = save_readwrite(fdin, fdout);
> #endif /* HAVE_SPLICE */
>-- 
>1.7.7.1
>