[pve-devel] [PATCH swtpm v2 02/16] swtpm setup: file: always just clear header rather than unlinking

[Fiona Ebner]

When using a FUSE export as the target file, it cannot be unlinked.
For block devices, the header is cleared, do the same for files.

Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
Reviewed-by: Daniel Kral <d.kral at proxmox.com>
Tested-by: Daniel Kral <d.kral at proxmox.com>
---
 src/swtpm_setup/swtpm_backend_file.c | 42 +++++++++++-----------------
 1 file changed, 17 insertions(+), 25 deletions(-)

diff --git a/src/swtpm_setup/swtpm_backend_file.c b/src/swtpm_setup/swtpm_backend_file.c
index a0d0f4d..d4ca2c5 100644
--- a/src/swtpm_setup/swtpm_backend_file.c
+++ b/src/swtpm_setup/swtpm_backend_file.c
@@ -57,36 +57,28 @@ static int check_access(void *state,
     return ret == 0 || errno == ENOENT ? 0 : 1;
 }
 
-/* Delete state from file: if regular file, unlink, if blockdev, zero header so
- * swtpm binary will treat it as a new instance. */
+/* Delete state from file: zero header so swtpm binary will treat it as a new
+ * instance. */
 static int delete_state(void *state) {
     const struct file_state *fstate = (struct file_state*)state;
     int fd;
 
-    if (fstate->is_blockdev) {
-        char zerobuf[8] = {0}; /* swtpm header has 8 byte */
-        fd = open(fstate->path, O_WRONLY);
-        if (fd < 0) {
-            logerr(gl_LOGFILE, "Couldn't open file for clearing %s: %s\n",
-                   fstate->path, strerror(errno));
-            return 1;
-        }
-        /* writing less bytes than requested is bad, but won't set errno */
-        errno = 0;
-        if (write(fd, zerobuf, sizeof(zerobuf)) < (long)sizeof(zerobuf)) {
-            logerr(gl_LOGFILE, "Couldn't write file for clearing %s: %s\n",
-                   fstate->path, strerror(errno));
-            close(fd);
-            return 1;
-        }
-        close(fd);
-    } else {
-        if (unlink(fstate->path)) {
-            logerr(gl_LOGFILE, "Couldn't unlink file for clearing %s: %s\n",
-                   fstate->path, strerror(errno));
-            return 1;
-        }
+    char zerobuf[8] = {0}; /* swtpm header has 8 byte */
+    fd = open(fstate->path, O_WRONLY);
+    if (fd < 0) {
+        logerr(gl_LOGFILE, "Couldn't open file for clearing %s: %s\n",
+               fstate->path, strerror(errno));
+        return 1;
     }
+    /* writing less bytes than requested is bad, but won't set errno */
+    errno = 0;
+    if (write(fd, zerobuf, sizeof(zerobuf)) < (long)sizeof(zerobuf)) {
+        logerr(gl_LOGFILE, "Couldn't write file for clearing %s: %s\n",
+               fstate->path, strerror(errno));
+        close(fd);
+        return 1;
+    }
+    close(fd);
 
     return 0;
 }
-- 
2.47.3