Clarify zpool_events_next() comment

Due to the very poorly chosen argument name 'cleanup_fd' it was
completely unclear that this file descriptor is used to track the
current cursor location.  When the file descriptor is created by
opening ZFS_DEV a private cursor is created in the kernel for the
returned file descriptor.  Subsequent calls to zpool_events_next()
and zpool_events_seek() then require the file descriptor as an
argument to reposition the cursor.  When the file descriptor is
closed the kernel state tracking the cursor is destroyed.

This patch contains no functional change, it just changes a
few variable names and clarifies the documentation.

Signed-off-by: Brian Behlendorf <[email protected]>
Signed-off-by: Chris Dunlap <[email protected]>
Issue #2

1 files changed, 5 insertions, 5 deletions

diff --git a/cmd/zpool/zpool_main.c b/cmd/zpool/zpool_main.c
index d095b15a5..4254f9b4d 100644
--- a/cmd/zpool/zpool_main.c
+++ b/cmd/zpool/zpool_main.c
@@ -5455,17 +5455,17 @@ static int
 zpool_do_events_next(ev_opts_t *opts)
 {
 	nvlist_t *nvl;
-	int cleanup_fd, ret, dropped;
+	int zevent_fd, ret, dropped;
 
-	cleanup_fd = open(ZFS_DEV, O_RDWR);
-	VERIFY(cleanup_fd >= 0);
+	zevent_fd = open(ZFS_DEV, O_RDWR);
+	VERIFY(zevent_fd >= 0);
 
 	if (!opts->scripted)
 		(void) printf(gettext("%-30s %s\n"), "TIME", "CLASS");
 
 	while (1) {
 		ret = zpool_events_next(g_zfs, &nvl, &dropped,
-		    !!opts->follow, cleanup_fd);
+		    !!opts->follow, zevent_fd);
 		if (ret || nvl == NULL)
 			break;
 
@@ -5483,7 +5483,7 @@ zpool_do_events_next(ev_opts_t *opts)
 		nvlist_free(nvl);
 	}
 
-	VERIFY(0 == close(cleanup_fd));
+	VERIFY(0 == close(zevent_fd));
 
 	return (ret);
 }