mirrors/libguestfs
1
0
Fork 0
mirror of https://github.com/libguestfs/libguestfs.git synced 2026-03-21 22:53:37 +00:00
Code Issues Packages Projects Releases Wiki Activity

lib: qemu: improve handling of FILE*

Browse Source 
Create own blocks for all the parts dealing with FILE*: this way there
is no need to recycle the same FILE* variable for all the operations,
and have each block its own variable automatically cleaned up.

This also fixes a potential undefined behaviour on error: POSIX says
that after a call fclose(), a FILE* cannot be used anymore, not even
on fclose() failure. The previous behaviour for fclose == -1 was to jump
to the error label, which would then try to call fclose() again (since
the FILE* pointer was still non-null).
This commit is contained in:
Pino Toscano
2017-03-06 14:23:55 +01:00
parent 18ee68ad12
commit d36940992e
1 changed files with 52 additions and 52 deletions
Download Patch File Download Diff File Expand all files Collapse all files

104
lib/qemu.c
View File

@@ -80,7 +80,6 @@ guestfs_int_test_qemu (guestfs_h *g, struct version *qemu_version)
struct stat statbuf;
CLEANUP_FREE char *cachedir = NULL, *qemu_stat_filename = NULL,
*qemu_help_filename = NULL, *qemu_devices_filename = NULL;
FILE *fp;
int generation;
uint64_t prev_size, prev_mtime;
@@ -101,15 +100,16 @@ guestfs_int_test_qemu (guestfs_h *g, struct version *qemu_version)
debug (g, "checking for previously cached test results of %s, in %s",
g->hv, cachedir);
fp = fopen (qemu_stat_filename, "r");
if (fp == NULL)
goto do_test;
if (fscanf (fp, "%d %" SCNu64 " %" SCNu64,
&generation, &prev_size, &prev_mtime) != 3) {
fclose (fp);
goto do_test;
{
CLEANUP_FCLOSE FILE *fp = NULL;
fp = fopen (qemu_stat_filename, "r");
if (fp == NULL)
goto do_test;
if (fscanf (fp, "%d %" SCNu64 " %" SCNu64,
&generation, &prev_size, &prev_mtime) != 3) {
goto do_test;
}
}
fclose (fp);
if (generation == MEMO_GENERATION &&
(uint64_t) statbuf.st_size == prev_size &&
@@ -153,54 +153,54 @@ guestfs_int_test_qemu (guestfs_h *g, struct version *qemu_version)
/* Now memoize the qemu output in the cache directory. */
debug (g, "saving test results");
fp = fopen (qemu_help_filename, "w");
if (fp == NULL) {
help_error:
perrorf (g, "%s", qemu_help_filename);
if (fp != NULL) fclose (fp);
guestfs_int_free_qemu_data (data);
return NULL;
{
CLEANUP_FCLOSE FILE *fp = NULL;
fp = fopen (qemu_help_filename, "w");
if (fp == NULL) {
help_error:
perrorf (g, "%s", qemu_help_filename);
guestfs_int_free_qemu_data (data);
return NULL;
}
if (fprintf (fp, "%s", data->qemu_help) == -1)
goto help_error;
}
if (fprintf (fp, "%s", data->qemu_help) == -1)
goto help_error;
if (fclose (fp) == -1)
goto help_error;
fp = fopen (qemu_devices_filename, "w");
if (fp == NULL) {
devices_error:
perrorf (g, "%s", qemu_devices_filename);
if (fp != NULL) fclose (fp);
guestfs_int_free_qemu_data (data);
return NULL;
{
CLEANUP_FCLOSE FILE *fp = NULL;
fp = fopen (qemu_devices_filename, "w");
if (fp == NULL) {
devices_error:
perrorf (g, "%s", qemu_devices_filename);
guestfs_int_free_qemu_data (data);
return NULL;
}
if (fprintf (fp, "%s", data->qemu_devices) == -1)
goto devices_error;
}
if (fprintf (fp, "%s", data->qemu_devices) == -1)
goto devices_error;
if (fclose (fp) == -1)
goto devices_error;
/* Write the qemu.stat file last so that its presence indicates that
* the qemu.help and qemu.devices files ought to exist.
*/
fp = fopen (qemu_stat_filename, "w");
if (fp == NULL) {
stat_error:
perrorf (g, "%s", qemu_stat_filename);
if (fp != NULL) fclose (fp);
guestfs_int_free_qemu_data (data);
return NULL;
{
/* Write the qemu.stat file last so that its presence indicates that
* the qemu.help and qemu.devices files ought to exist.
*/
CLEANUP_FCLOSE FILE *fp = NULL;
fp = fopen (qemu_stat_filename, "w");
if (fp == NULL) {
stat_error:
perrorf (g, "%s", qemu_stat_filename);
guestfs_int_free_qemu_data (data);
return NULL;
}
/* The path to qemu is stored for information only, it is not
* used when we parse the file.
*/
if (fprintf (fp, "%d %" PRIu64 " %" PRIu64 " %s\n",
MEMO_GENERATION,
(uint64_t) statbuf.st_size,
(uint64_t) statbuf.st_mtime,
g->hv) == -1)
goto stat_error;
}
/* The path to qemu is stored for information only, it is not
* used when we parse the file.
*/
if (fprintf (fp, "%d %" PRIu64 " %" PRIu64 " %s\n",
MEMO_GENERATION,
(uint64_t) statbuf.st_size,
(uint64_t) statbuf.st_mtime,
g->hv) == -1)
goto stat_error;
if (fclose (fp) == -1)
goto stat_error;
return data;
}