Fix ztest vdev file paths.

Currently, in several instances (but not all), ztest generates vdev
file paths using a statement similar to this:

    snprintf(path, sizeof (path), ztest_dev_template, ...);

This worked fine until 40b84e7aec6392187722e61e5a4a853b530bf60f, which
changed path to be a pointer to the heap instead of an array allocated
on the stack. Before this change, sizeof(path) would return the size of
the array; now, it returns the size of the pointer instead.

As a result, the aforementioned sprintf statement uses the wrong size
and truncates the vdev file path to the first 4 or 8 bytes (depending
on the architecture). Typically, with default settings, the file path
will become "/tmp/zt" instead of "/test/ztest.XXX".

This issue only exists in ztest_vdev_attach_detach() and
ztest_fault_inject(), which explains why ztest doesn't fail right away.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #989

diff --git a/cmd/ztest/ztest.c b/cmd/ztest/ztest.c
index ff14c672232ceb6a5a1b8dfbb18cd808db9415dc..4aca527e8c3bd001e9cc3f65ad4688f0a5423b15 100644 (file)
--- a/cmd/ztest/ztest.c
+++ b/cmd/ztest/ztest.c
@@ -2567,7 +2567,7 @@ ztest_vdev_attach_detach(ztest_ds_t *zd, uint64_t id)
                newvd_is_spare = B_TRUE;
                (void) strcpy(newpath, newvd->vdev_path);
        } else {
-               (void) snprintf(newpath, sizeof (newpath), ztest_dev_template,
+               (void) snprintf(newpath, MAXPATHLEN, ztest_dev_template,
                    zopt_dir, zopt_pool, top * leaves + leaf);
                if (ztest_random(2) == 0)
                        newpath[strlen(newpath) - 1] = 'b';
@@ -4633,9 +4633,9 @@ ztest_fault_inject(ztest_ds_t *zd, uint64_t id)
                 * write failures and random online/offline activity on leaf 0,
                 * and we'll write random garbage to the randomly chosen leaf.
                 */
-               (void) snprintf(path0, sizeof (path0), ztest_dev_template,
+               (void) snprintf(path0, MAXPATHLEN, ztest_dev_template,
                    zopt_dir, zopt_pool, top * leaves + zs->zs_splits);
-               (void) snprintf(pathrand, sizeof (pathrand), ztest_dev_template,
+               (void) snprintf(pathrand, MAXPATHLEN, ztest_dev_template,
                    zopt_dir, zopt_pool, top * leaves + leaf);
 
                vd0 = vdev_lookup_by_path(spa->spa_root_vdev, path0);
@@ -4999,7 +4999,7 @@ ztest_run_zdb(char *pool)
 
        fp = popen(zdb, "r");
 
-       while (fgets(zbuf, sizeof (zbuf), fp) != NULL)
+       while (fgets(zbuf, 1024, fp) != NULL)
                if (zopt_verbose >= 3)
                        (void) printf("%s", zbuf);