[Libguestfs] [nbdkit PATCH] file: Diagnose a missing file earlier
If a user typos the filename for the file plugin, they do not
find out about it until later when the first client gets an
abrupt hangup, when file_open() fails to open things. Better
is to avoid starting a server at all if the file doesn't exist
yet.
While at it, avoid a memory leak if the caller passes a file=
argument more than once.
Signed-off-by: Eric Blake <eblake(a)redhat.com>
---
plugins/file/file.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/plugins/file/file.c b/plugins/file/file.c
index ef5da3d..4a91251 100644
--- a/plugins/file/file.c
+++ b/plugins/file/file.c
@@ -117,6 +117,7 @@ file_config (const char *key, const char *value)
{
if (strcmp (key, "file") == 0) {
/* See FILENAMES AND PATHS in nbdkit-plugin(3). */
+ free (filename);
filename = nbdkit_absolute_path (value);
if (!filename)
return -1;
@@ -147,6 +148,10 @@ file_config_complete (void)
nbdkit_error ("you must supply the file=<FILENAME> parameter after the
plugin name on the command line");
return -1;
}
+ if (access (filename, F_OK) < 0) {
+ nbdkit_error ("access '%s': %m", filename);
+ return -1;
+ }
return 0;
}
--
2.13.6