Use shifts in minix filesystem.

	* grub-core/fs/minix.c (GRUB_MINIX_ZONESZ): Use log_block_size.
	(GRUB_MINIX_ZONE2SECT): Likewise.
	(grub_minix_data): Replace block_size with log_block_size.
	(grub_minix_read_file): Use shifts.
	(grub_minix_mount): Check block size and take a logarithm.

diff --git a/ChangeLog b/ChangeLog
index 6d0cfde930f117df1c0a9011bf9282f2d53ffb3a..f73d431d2dc5866133daacbeb2c925845d1ecdbd 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2011-10-28  Vladimir Serbinenko  <phcoder@gmail.com>
+
+       Use shifts in minix filesystem.
+
+       * grub-core/fs/minix.c (GRUB_MINIX_ZONESZ): Use log_block_size.
+       (GRUB_MINIX_ZONE2SECT): Likewise.
+       (grub_minix_data): Replace block_size with log_block_size.
+       (grub_minix_read_file): Use shifts.
+       (grub_minix_mount): Check block size and take a logarithm.
+
 2011-10-28  Vladimir Serbinenko  <phcoder@gmail.com>
 
        Use shifts in squash4.

diff --git a/grub-core/fs/minix.c b/grub-core/fs/minix.c
index 43785b6571eff9e80f3dca3aa39f4ee5d13dd43f..401883e36d14f47d87c92f666680ccf44539611c 100644 (file)
--- a/grub-core/fs/minix.c
+++ b/grub-core/fs/minix.c
@@ -76,11 +76,11 @@ typedef grub_uint16_t grub_minix_ino_t;
 #define GRUB_MINIX_LOG2_ZONESZ (GRUB_MINIX_LOG2_BSIZE                          \
                                 + grub_le_to_cpu16 (data->sblock.log2_zone_size))
 #endif
-#define GRUB_MINIX_ZONESZ      (data->block_size                               \
-                                << grub_le_to_cpu16 (data->sblock.log2_zone_size))
+#define GRUB_MINIX_ZONESZ      (1 << (data->log_block_size             \
+                                      + grub_le_to_cpu16 (data->sblock.log2_zone_size)))
 
 #ifdef MODE_MINIX3
-#define GRUB_MINIX_ZONE2SECT(zone) ((zone) * (data->block_size / GRUB_DISK_SECTOR_SIZE))
+#define GRUB_MINIX_ZONE2SECT(zone) ((zone) << (data->log_block_size - GRUB_DISK_SECTOR_BITS))
 #else
 #define GRUB_MINIX_ZONE2SECT(zone) ((zone) << GRUB_MINIX_LOG2_ZONESZ)
 #endif
@@ -159,7 +159,7 @@ struct grub_minix_data
   int linknest;
   grub_disk_t disk;
   int filename_size;
-  grub_size_t block_size;
+  grub_size_t log_block_size;
 };
 
 static grub_dl_t my_mod;
@@ -251,14 +251,15 @@ grub_minix_read_file (struct grub_minix_data *data,
   if (len + pos > GRUB_MINIX_INODE_SIZE (data))
     len = GRUB_MINIX_INODE_SIZE (data) - pos;
 
-  blockcnt = grub_divmod64 ((len + pos + data->block_size - 1),
-                           data->block_size, 0);
-  posblock = grub_divmod64 (pos, data->block_size, &blockoff);
+  blockcnt = ((len + pos + (1 << data->log_block_size) - 1)
+             >> data->log_block_size);
+  posblock = pos >> data->log_block_size;
+  blockoff = pos & ((1 << data->log_block_size) - 1);
 
   for (i = posblock; i < blockcnt; i++)
     {
       grub_disk_addr_t blknr;
-      grub_uint64_t blockend = data->block_size;
+      grub_uint64_t blockend = 1 << data->log_block_size;
       grub_off_t skipfirst = 0;
 
       blknr = grub_minix_get_file_block (data, i);
@@ -268,10 +269,10 @@ grub_minix_read_file (struct grub_minix_data *data,
       /* Last block.  */
       if (i == blockcnt - 1)
        {
-         grub_divmod64 (len + pos, data->block_size, &blockend);
+         blockend = (len + pos) & ((1 << data->log_block_size) - 1);
 
          if (!blockend)
-           blockend = data->block_size;
+           blockend = 1 << data->log_block_size;
        }
 
       /* First block.  */
@@ -289,7 +290,7 @@ grub_minix_read_file (struct grub_minix_data *data,
       if (grub_errno)
        return -1;
 
-      buf += data->block_size - skipfirst;
+      buf += (1 << data->log_block_size) - skipfirst;
     }
 
   return len;
@@ -479,9 +480,14 @@ grub_minix_mount (grub_disk_t disk)
   data->disk = disk;
   data->linknest = 0;
 #ifdef MODE_MINIX3
-  data->block_size = grub_le_to_cpu16 (data->sblock.block_size);
+  if ((grub_le_to_cpu16 (data->sblock.block_size)
+       & (grub_le_to_cpu16 (data->sblock.block_size) - 1))
+      || grub_le_to_cpu16 (data->sblock.block_size) == 0)
+    goto fail;
+  for (data->log_block_size = 0; (1 << data->log_block_size)
+        < grub_le_to_cpu16 (data->sblock.block_size); data->log_block_size++);
 #else
-  data->block_size = 1024U;
+  data->log_block_size = 10;
 #endif
 
   return data;