From 31bf0cf313f21bdeb0d166c4c76aad050ad32232 Mon Sep 17 00:00:00 2001 From: "Richard W.M. Jones" Date: Fri, 21 Oct 2011 16:29:20 +0100 Subject: [PATCH] add-drive-opts: Correctly handle unreadable and unwritable files (RHBZ#747287). --- src/launch.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/src/launch.c b/src/launch.c index ce26e25..1988f70 100644 --- a/src/launch.c +++ b/src/launch.c @@ -233,17 +233,21 @@ guestfs__config (guestfs_h *g, * O_DIRECT. This fails on some filesystem types (notably tmpfs). * So we check if we can open the file with or without O_DIRECT, * and use cache=off (or not) accordingly. + * + * NB: This function is only called on the !readonly path. We must + * try to open with O_RDWR to test that the file is readable and + * writable here. */ static int test_cache_off (guestfs_h *g, const char *filename) { - int fd = open (filename, O_RDONLY|O_DIRECT); + int fd = open (filename, O_RDWR|O_DIRECT); if (fd >= 0) { close (fd); return 1; } - fd = open (filename, O_RDONLY); + fd = open (filename, O_RDWR); if (fd >= 0) { close (fd); return 0; @@ -325,7 +329,7 @@ guestfs__add_drive_opts (guestfs_h *g, const char *filename, } if (readonly) { - if (access (filename, F_OK) == -1) { + if (access (filename, R_OK) == -1) { perrorf (g, "%s", filename); free (format); free (iface); @@ -853,6 +857,13 @@ launch_appliance (guestfs_h *g) if (r == -1) goto cleanup1; + /* NB: We reach here just because qemu has opened the socket. It + * does not mean the daemon is up until we read the + * GUESTFS_LAUNCH_FLAG below. Failures in qemu startup can still + * happen even if we reach here, even early failures like not being + * able to open a drive. + */ + close (g->sock); /* Close the listening socket. */ g->sock = r; /* This is the accepted data socket. */ -- 1.8.3.1