From: Julien Desfossez <julien.desfossez@polymtl.ca>
Date: Tue, 24 May 2011 14:15:47 +0000 (-0400)
Subject: Handle splice errors
X-Git-Tag: v2.0-pre1~131
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=0632499a602c5588da22d191c14827be3b86a01a;p=lttng-tools.git

Handle splice errors

Send to the session daemon the eventual error returned by splice.

Signed-off-by: David Goulet <david.goulet@polymtl.ca>
---

diff --git a/kconsumerd/kconsumerd.c b/kconsumerd/kconsumerd.c
index 7e166b8f1..a00f07932 100644
--- a/kconsumerd/kconsumerd.c
+++ b/kconsumerd/kconsumerd.c
@@ -260,16 +260,18 @@ static int on_read_subbuffer(struct ltt_kconsumerd_fd *kconsumerd_fd,
 				SPLICE_F_MOVE | SPLICE_F_MORE);
 		DBG("splice chan to pipe ret %ld", ret);
 		if (ret < 0) {
+			ret = errno;
 			perror("Error in relay splice");
-			goto write_end;
+			goto splice_error;
 		}
 
 		ret = splice(thread_pipe[0], NULL, outfd, NULL, ret,
 				SPLICE_F_MOVE | SPLICE_F_MORE);
 		DBG("splice pipe to file %ld", ret);
 		if (ret < 0) {
+			ret = errno;
 			perror("Error in file splice");
-			goto write_end;
+			goto splice_error;
 		}
 		if (ret >= len) {
 			len = 0;
@@ -279,7 +281,7 @@ static int on_read_subbuffer(struct ltt_kconsumerd_fd *kconsumerd_fd,
 				SYNC_FILE_RANGE_WRITE);
 		kconsumerd_fd->out_fd_offset += ret;
 	}
-write_end:
+
 	/*
 	 * This does a blocking write-and-wait on any page that belongs to the
 	 * subbuffer prior to the one we just wrote.
@@ -307,6 +309,26 @@ write_end:
 		posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size,
 				kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED);
 	}
+	goto end;
+
+splice_error:
+	/* send the appropriate error description to sessiond */
+	switch(ret) {
+		case EBADF:
+			send_error(KCONSUMERD_SPLICE_EBADF);
+			break;
+		case EINVAL:
+			send_error(KCONSUMERD_SPLICE_EINVAL);
+			break;
+		case ENOMEM:
+			send_error(KCONSUMERD_SPLICE_ENOMEM);
+			break;
+		case ESPIPE:
+			send_error(KCONSUMERD_SPLICE_ESPIPE);
+			break;
+	}
+
+end:
 	return ret;
 }
 
diff --git a/liblttsessiondcomm/liblttsessiondcomm.c b/liblttsessiondcomm/liblttsessiondcomm.c
index d754f59da..19bda8388 100644
--- a/liblttsessiondcomm/liblttsessiondcomm.c
+++ b/liblttsessiondcomm/liblttsessiondcomm.c
@@ -60,6 +60,10 @@ static const char *lttcomm_readable_code[] = {
 	[ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_SUCCESS) ] = "Kconsumerd exiting normally",
 	[ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_FAILURE) ] = "Kconsumerd exiting on error",
 	[ LTTCOMM_ERR_INDEX(KCONSUMERD_OUTFD_ERROR) ] = "Kconsumerd error opening the tracefile",
+	[ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EBADF) ] = "Kconsumerd splice EBADF",
+	[ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EINVAL) ] = "Kconsumerd splice EINVAL",
+	[ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ENOMEM) ] = "Kconsumerd splice ENOMEM",
+	[ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ESPIPE) ] = "Kconsumerd splice ESPIPE",
 	[ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "No event found",
 };
 
diff --git a/liblttsessiondcomm/liblttsessiondcomm.h b/liblttsessiondcomm/liblttsessiondcomm.h
index 8e6a862ef..580d4c2c7 100644
--- a/liblttsessiondcomm/liblttsessiondcomm.h
+++ b/liblttsessiondcomm/liblttsessiondcomm.h
@@ -112,6 +112,10 @@ enum lttcomm_return_code {
 	KCONSUMERD_EXIT_SUCCESS,		/* kconsumerd exiting normally */
 	KCONSUMERD_EXIT_FAILURE,		/* kconsumerd exiting on error */
 	KCONSUMERD_OUTFD_ERROR,			/* error opening the tracefile */
+	KCONSUMERD_SPLICE_EBADF,		/* EBADF from splice(2) */
+	KCONSUMERD_SPLICE_EINVAL,		/* EINVAL from splice(2) */
+	KCONSUMERD_SPLICE_ENOMEM,		/* ENOMEM from splice(2) */
+	KCONSUMERD_SPLICE_ESPIPE,		/* ESPIPE from splice(2) */
 	/* MUST be last element */
 	LTTCOMM_NR,						/* Last element */
 };