1 files changed, 131 insertions, 140 deletions

diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 58b78ba57439..c98ae818eb4e 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -4,6 +4,7 @@
  * Copyright 31 August 2008 James Bottomley
  * Copyright (C) 2013, Intel Corporation
  */
+#include <linux/bug.h>
 #include <linux/kernel.h>
 #include <linux/math64.h>
 #include <linux/export.h>
@@ -14,25 +15,25 @@
 
 /**
  * string_get_size - get the size in the specified units
- * @size:       The size to be converted
+ * @size:       The size to be converted in blocks
+ * @blk_size:   Size of the block (use 1 for size in bytes)
  * @units:      units to use (powers of 1000 or 1024)
  * @buf:        buffer to format to
  * @len:        length of buffer
  *
  * This function returns a string formatted to 3 significant figures
- * giving the size in the required units.  Returns 0 on success or
- * error on failure.  @buf is always zero terminated.
+ * giving the size in the required units.  @buf should have room for
+ * at least 9 bytes and will always be zero terminated.
  *
  */
-int string_get_size(u64 size, const enum string_size_units units,
-                    char *buf, int len)
+void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
+                     char *buf, int len)
 {
         static const char *const units_10[] = {
-                "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB", NULL
+                "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
         };
         static const char *const units_2[] = {
-                "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB",
-                NULL
+                "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"
         };
         static const char *const *const units_str[] = {
                 [STRING_UNITS_10] = units_10,
@@ -43,34 +44,57 @@ int string_get_size(u64 size, const enum string_size_units units,
                 [STRING_UNITS_2] = 1024,
         };
         int i, j;
-        u64 remainder = 0, sf_cap;
+        u32 remainder = 0, sf_cap, exp;
         char tmp[8];
+        const char *unit;
 
         tmp[0] = '\0';
         i = 0;
-        if (size >= divisor[units]) {
-                while (size >= divisor[units] && units_str[units][i]) {
-                        remainder = do_div(size, divisor[units]);
-                        i++;
-                }
+        if (!size)
+                goto out;
 
-                sf_cap = size;
-                for (j = 0; sf_cap*10 < 1000; j++)
-                        sf_cap *= 10;
+        while (blk_size >= divisor[units]) {
+                remainder = do_div(blk_size, divisor[units]);
+                i++;
+        }
 
-                if (j) {
-                        remainder *= 1000;
-                        do_div(remainder, divisor[units]);
-                        snprintf(tmp, sizeof(tmp), ".%03lld",
-                                 (unsigned long long)remainder);
-                        tmp[j+1] = '\0';
-                }
+        exp = divisor[units] / (u32)blk_size;
+        if (size >= exp) {
+                remainder = do_div(size, divisor[units]);
+                remainder *= blk_size;
+                i++;
+        } else {
+                remainder *= size;
+        }
+
+        size *= blk_size;
+        size += remainder / divisor[units];
+        remainder %= divisor[units];
+
+        while (size >= divisor[units]) {
+                remainder = do_div(size, divisor[units]);
+                i++;
         }
 
-        snprintf(buf, len, "%lld%s %s", (unsigned long long)size,
-                 tmp, units_str[units][i]);
+        sf_cap = size;
+        for (j = 0; sf_cap*10 < 1000; j++)
+                sf_cap *= 10;
 
-        return 0;
+        if (j) {
+                remainder *= 1000;
+                remainder /= divisor[units];
+                snprintf(tmp, sizeof(tmp), ".%03u", remainder);
+                tmp[j+1] = '\0';
+        }
+
+ out:
+        if (i >= ARRAY_SIZE(units_2))
+                unit = "UNK";
+        else
+                unit = units_str[units][i];
+
+        snprintf(buf, len, "%u%s %s", (u32)size,
+                 tmp, unit);
 }
 EXPORT_SYMBOL(string_get_size);
 
@@ -243,29 +267,21 @@ int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
 }
 EXPORT_SYMBOL(string_unescape);
 
-static int escape_passthrough(unsigned char c, char **dst, size_t *osz)
+static bool escape_passthrough(unsigned char c, char **dst, char *end)
 {
         char *out = *dst;
 
-        if (*osz < 1)
-                return -ENOMEM;
-
-        *out++ = c;
-
-        *dst = out;
-        *osz -= 1;
-
-        return 1;
+        if (out < end)
+                *out = c;
+        *dst = out + 1;
+        return true;
 }
 
-static int escape_space(unsigned char c, char **dst, size_t *osz)
+static bool escape_space(unsigned char c, char **dst, char *end)
 {
         char *out = *dst;
         unsigned char to;
 
-        if (*osz < 2)
-                return -ENOMEM;
-
         switch (c) {
         case '\n':
                 to = 'n';
@@ -283,26 +299,25 @@ static int escape_space(unsigned char c, char **dst, size_t *osz)
                 to = 'f';
                 break;
         default:
-                return 0;
+                return false;
         }
 
-        *out++ = '\\';
-        *out++ = to;
+        if (out < end)
+                *out = '\\';
+        ++out;
+        if (out < end)
+                *out = to;
+        ++out;
 
         *dst = out;
-        *osz -= 2;
-
-        return 1;
+        return true;
 }
 
-static int escape_special(unsigned char c, char **dst, size_t *osz)
+static bool escape_special(unsigned char c, char **dst, char *end)
 {
         char *out = *dst;
         unsigned char to;
 
-        if (*osz < 2)
-                return -ENOMEM;
-
         switch (c) {
         case '\\':
                 to = '\\';
@@ -314,71 +329,78 @@ static int escape_special(unsigned char c, char **dst, size_t *osz)
                 to = 'e';
                 break;
         default:
-                return 0;
+                return false;
         }
 
-        *out++ = '\\';
-        *out++ = to;
+        if (out < end)
+                *out = '\\';
+        ++out;
+        if (out < end)
+                *out = to;
+        ++out;
 
         *dst = out;
-        *osz -= 2;
-
-        return 1;
+        return true;
 }
 
-static int escape_null(unsigned char c, char **dst, size_t *osz)
+static bool escape_null(unsigned char c, char **dst, char *end)
 {
         char *out = *dst;
 
-        if (*osz < 2)
-                return -ENOMEM;
-
         if (c)
-                return 0;
+                return false;
 
-        *out++ = '\\';
-        *out++ = '0';
+        if (out < end)
+                *out = '\\';
+        ++out;
+        if (out < end)
+                *out = '0';
+        ++out;
 
         *dst = out;
-        *osz -= 2;
-
-        return 1;
+        return true;
 }
 
-static int escape_octal(unsigned char c, char **dst, size_t *osz)
+static bool escape_octal(unsigned char c, char **dst, char *end)
 {
         char *out = *dst;
 
-        if (*osz < 4)
-                return -ENOMEM;
-
-        *out++ = '\\';
-        *out++ = ((c >> 6) & 0x07) + '0';
-        *out++ = ((c >> 3) & 0x07) + '0';
-        *out++ = ((c >> 0) & 0x07) + '0';
+        if (out < end)
+                *out = '\\';
+        ++out;
+        if (out < end)
+                *out = ((c >> 6) & 0x07) + '0';
+        ++out;
+        if (out < end)
+                *out = ((c >> 3) & 0x07) + '0';
+        ++out;
+        if (out < end)
+                *out = ((c >> 0) & 0x07) + '0';
+        ++out;
 
         *dst = out;
-        *osz -= 4;
-
-        return 1;
+        return true;
 }
 
-static int escape_hex(unsigned char c, char **dst, size_t *osz)
+static bool escape_hex(unsigned char c, char **dst, char *end)
 {
         char *out = *dst;
 
-        if (*osz < 4)
-                return -ENOMEM;
-
-        *out++ = '\\';
-        *out++ = 'x';
-        *out++ = hex_asc_hi(c);
-        *out++ = hex_asc_lo(c);
+        if (out < end)
+                *out = '\\';
+        ++out;
+        if (out < end)
+                *out = 'x';
+        ++out;
+        if (out < end)
+                *out = hex_asc_hi(c);
+        ++out;
+        if (out < end)
+                *out = hex_asc_lo(c);
+        ++out;
 
         *dst = out;
-        *osz -= 4;
-
-        return 1;
+        return true;
 }
 
 /**
@@ -430,19 +452,17 @@ static int escape_hex(unsigned char c, char **dst, size_t *osz)
  * it if needs.
  *
  * Return:
- * The amount of the characters processed to the destination buffer, or
- * %-ENOMEM if the size of buffer is not enough to put an escaped character is
- * returned.
- *
- * Even in the case of error @dst pointer will be updated to point to the byte
- * after the last processed character.
+ * The total size of the escaped output that would be generated for
+ * the given input and flags. To check whether the output was
+ * truncated, compare the return value to osz. There is room left in
+ * dst for a '\0' terminator if and only if ret < osz.
  */
-int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
+int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
                       unsigned int flags, const char *esc)
 {
-        char *out = *dst, *p = out;
+        char *p = dst;
+        char *end = p + osz;
         bool is_dict = esc && *esc;
-        int ret = 0;
 
         while (isz--) {
                 unsigned char c = *src++;
@@ -462,55 +482,26 @@ int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
                     (is_dict && !strchr(esc, c))) {
                         /* do nothing */
                 } else {
-                        if (flags & ESCAPE_SPACE) {
-                                ret = escape_space(c, &p, &osz);
-                                if (ret < 0)
-                                        break;
-                                if (ret > 0)
-                                        continue;
-                        }
-
-                        if (flags & ESCAPE_SPECIAL) {
-                                ret = escape_special(c, &p, &osz);
-                                if (ret < 0)
-                                        break;
-                                if (ret > 0)
-                                        continue;
-                        }
-
-                        if (flags & ESCAPE_NULL) {
-                                ret = escape_null(c, &p, &osz);
-                                if (ret < 0)
-                                        break;
-                                if (ret > 0)
-                                        continue;
-                        }
+                        if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
+                                continue;
+
+                        if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
+                                continue;
+
+                        if (flags & ESCAPE_NULL && escape_null(c, &p, end))
+                                continue;
 
                         /* ESCAPE_OCTAL and ESCAPE_HEX always go last */
-                        if (flags & ESCAPE_OCTAL) {
-                                ret = escape_octal(c, &p, &osz);
-                                if (ret < 0)
-                                        break;
+                        if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
                                 continue;
-                        }
-                        if (flags & ESCAPE_HEX) {
-                                ret = escape_hex(c, &p, &osz);
-                                if (ret < 0)
-                                        break;
+
+                        if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
                                 continue;
-                        }
                 }
 
-                ret = escape_passthrough(c, &p, &osz);
-                if (ret < 0)
-                        break;
+                escape_passthrough(c, &p, end);
         }
 
-        *dst = p;
-
-        if (ret < 0)
-                return ret;
-
-        return p - out;
+        return p - dst;
 }
 EXPORT_SYMBOL(string_escape_mem);