Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2021-03-09' into staging

nbd patches for 2021-03-09

- Add Vladimir as NBD co-maintainer
- Fix reporting of holes in NBD_CMD_BLOCK_STATUS
- Improve command-line parsing accuracy of large numbers (anything going
through qemu_strtosz), including the deprecation of hex+suffix
- Improve some error reporting in the block layer

# gpg: Signature made Tue 09 Mar 2021 15:38:10 GMT
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2021-03-09:
  block/qcow2: refactor qcow2_update_options_prepare error paths
  block/qed: bdrv_qed_do_open: deal with errp
  block/qcow2: simplify qcow2_co_invalidate_cache()
  block/qcow2: read_cache_sizes: return status value
  block/qcow2-bitmap: return status from qcow2_store_persistent_dirty_bitmaps
  block/qcow2-bitmap: improve qcow2_load_dirty_bitmaps() interface
  block/qcow2: qcow2_get_specific_info(): drop error propagation
  blockjob: return status from block_job_set_speed()
  block/mirror: drop extra error propagation in commit_active_start()
  block: drop extra error propagation for bdrv_set_backing_hd
  blockdev: fix drive_backup_prepare() missed error
  block: check return value of bdrv_open_child and drop error propagation
  utils: Deprecate hex-with-suffix sizes
  utils: Improve qemu_strtosz() to have 64 bits of precision
  utils: Enhance testsuite for do_strtosz()
  nbd: server: Report holes for raw images
  MAINTAINERS: add Vladimir as co-maintainer of NBD

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 77 insertions, 21 deletions

diff --git a/util/cutils.c b/util/cutils.c
index 70c7d6efbd..d89a40a8c3 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -241,52 +241,108 @@ static int64_t suffix_mul(char suffix, int64_t unit)
 }
 
 /*
- * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
- * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
- * in *end, if not NULL. Return -ERANGE on overflow, and -EINVAL on
- * other error.
+ * Convert size string to bytes.
+ *
+ * The size parsing supports the following syntaxes
+ * - 12345 - decimal, scale determined by @default_suffix and @unit
+ * - 12345{bBkKmMgGtTpPeE} - decimal, scale determined by suffix and @unit
+ * - 12345.678{kKmMgGtTpPeE} - decimal, scale determined by suffix, and
+ *   fractional portion is truncated to byte
+ * - 0x7fEE - hexadecimal, unit determined by @default_suffix
+ *
+ * The following cause a deprecation warning, and may be removed in the future
+ * - 0xabc{kKmMgGtTpP} - hex with scaling suffix
+ *
+ * The following are intentionally not supported
+ * - octal, such as 08
+ * - fractional hex, such as 0x1.8
+ * - floating point exponents, such as 1e3
+ *
+ * The end pointer will be returned in *end, if not NULL.  If there is
+ * no fraction, the input can be decimal or hexadecimal; if there is a
+ * fraction, then the input must be decimal and there must be a suffix
+ * (possibly by @default_suffix) larger than Byte, and the fractional
+ * portion may suffer from precision loss or rounding.  The input must
+ * be positive.
+ *
+ * Return -ERANGE on overflow (with *@end advanced), and -EINVAL on
+ * other error (with *@end left unchanged).
  */
 static int do_strtosz(const char *nptr, const char **end,
                       const char default_suffix, int64_t unit,
                       uint64_t *result)
 {
     int retval;
-    const char *endptr;
+    const char *endptr, *f;
     unsigned char c;
-    int mul_required = 0;
-    double val, mul, integral, fraction;
+    bool mul_required = false, hex = false;
+    uint64_t val;
+    int64_t mul;
+    double fraction = 0.0;
 
-    retval = qemu_strtod_finite(nptr, &endptr, &val);
+    /* Parse integral portion as decimal. */
+    retval = qemu_strtou64(nptr, &endptr, 10, &val);
     if (retval) {
         goto out;
     }
-    fraction = modf(val, &integral);
-    if (fraction != 0) {
-        mul_required = 1;
+    if (memchr(nptr, '-', endptr - nptr) != NULL) {
+        endptr = nptr;
+        retval = -EINVAL;
+        goto out;
+    }
+    if (val == 0 && (*endptr == 'x' || *endptr == 'X')) {
+        /* Input looks like hex, reparse, and insist on no fraction. */
+        retval = qemu_strtou64(nptr, &endptr, 16, &val);
+        if (retval) {
+            goto out;
+        }
+        if (*endptr == '.') {
+            endptr = nptr;
+            retval = -EINVAL;
+            goto out;
+        }
+        hex = true;
+    } else if (*endptr == '.') {
+        /*
+         * Input looks like a fraction.  Make sure even 1.k works
+         * without fractional digits.  If we see an exponent, treat
+         * the entire input as invalid instead.
+         */
+        f = endptr;
+        retval = qemu_strtod_finite(f, &endptr, &fraction);
+        if (retval) {
+            fraction = 0.0;
+            endptr++;
+        } else if (memchr(f, 'e', endptr - f) || memchr(f, 'E', endptr - f)) {
+            endptr = nptr;
+            retval = -EINVAL;
+            goto out;
+        } else if (fraction != 0) {
+            mul_required = true;
+        }
     }
     c = *endptr;
     mul = suffix_mul(c, unit);
-    if (mul >= 0) {
+    if (mul > 0) {
+        if (hex) {
+            warn_report("Using a multiplier suffix on hex numbers "
+                        "is deprecated: %s", nptr);
+        }
         endptr++;
     } else {
         mul = suffix_mul(default_suffix, unit);
-        assert(mul >= 0);
+        assert(mul > 0);
     }
     if (mul == 1 && mul_required) {
+        endptr = nptr;
         retval = -EINVAL;
         goto out;
     }
-    /*
-     * Values near UINT64_MAX overflow to 2**64 when converting to double
-     * precision.  Compare against the maximum representable double precision
-     * value below 2**64, computed as "the next value after 2**64 (0x1p64) in
-     * the direction of 0".
-     */
-    if ((val * mul > nextafter(0x1p64, 0)) || val < 0) {
+    if (val > (UINT64_MAX - ((uint64_t) (fraction * mul))) / mul) {
         retval = -ERANGE;
         goto out;
     }
-    *result = val * mul;
+    *result = val * mul + (uint64_t) (fraction * mul);
     retval = 0;
 
 out: