libext2fs: Fix FEATURE_RO_COMPAT_HUGE_FILE && !HUGE_FILE_FL

If the RO compat HUGE_FILE feature flag is set, but the inode's
HUGE_FILE_FL flag is not set, we should still pay attention to the
high 32 bits of the i_blocks filed.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/ext2fs/i_block.c b/lib/ext2fs/i_block.c
index c7e5c44..6e1b136 100644 (file)
--- a/lib/ext2fs/i_block.c
+++ b/lib/ext2fs/i_block.c
@@ -21,6 +21,7 @@
 #if HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
+#include <errno.h>
 
 #include "ext2_fs.h"
 #include "ext2fs.h"
@@ -28,48 +29,60 @@
 errcode_t ext2fs_iblk_add_blocks(ext2_filsys fs, struct ext2_inode *inode,
                                 blk64_t num_blocks)
 {
-       unsigned long long b;
+       unsigned long long b = inode->i_blocks;
 
-       if ((fs->super->s_feature_ro_compat &
-            EXT4_FEATURE_RO_COMPAT_HUGE_FILE) &&
-           (inode->i_flags & EXT4_HUGE_FILE_FL)) {
-               b = inode->i_blocks +
-                       (((long long) inode->osd2.linux2.l_i_blocks_hi) << 32);
-               b += num_blocks;
-               inode->i_blocks = b & 0xFFFFFFFF;
+       if (!(fs->super->s_feature_ro_compat &
+             EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
+           !(inode->i_flags & EXT4_HUGE_FILE_FL))
+           num_blocks *= fs->blocksize / 512;
+
+       b += num_blocks;
+
+       if (fs->super->s_feature_ro_compat &
+           EXT4_FEATURE_RO_COMPAT_HUGE_FILE) {
+               b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
                inode->osd2.linux2.l_i_blocks_hi = b >> 32;
-       } else
-               inode->i_blocks += (fs->blocksize / 512) * num_blocks;
+       } else if (b > 0xFFFFFFFF)
+               return EOVERFLOW;
+       inode->i_blocks = b & 0xFFFFFFFF;
        return 0;
 }
 
-
 errcode_t ext2fs_iblk_sub_blocks(ext2_filsys fs, struct ext2_inode *inode,
                                 blk64_t num_blocks)
 {
-       unsigned long long b;
+       unsigned long long b = inode->i_blocks;
+
+       if (!(fs->super->s_feature_ro_compat &
+             EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
+           !(inode->i_flags & EXT4_HUGE_FILE_FL))
+           num_blocks *= fs->blocksize / 512;
 
-       if ((fs->super->s_feature_ro_compat &
-            EXT4_FEATURE_RO_COMPAT_HUGE_FILE) &&
-           (inode->i_flags & EXT4_HUGE_FILE_FL)) {
-               b = inode->i_blocks +
-                       (((long long) inode->osd2.linux2.l_i_blocks_hi) << 32);
-               b -= num_blocks;
-               inode->i_blocks = b & 0xFFFFFFFF;
+       if (num_blocks > b)
+               return EOVERFLOW;
+
+       b -= num_blocks;
+
+       if (fs->super->s_feature_ro_compat &
+           EXT4_FEATURE_RO_COMPAT_HUGE_FILE) {
+               b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
                inode->osd2.linux2.l_i_blocks_hi = b >> 32;
-       } else
-               inode->i_blocks -= (fs->blocksize / 512) * num_blocks;
+       }
+       inode->i_blocks = b & 0xFFFFFFFF;
        return 0;
 }
 
 errcode_t ext2fs_iblk_set(ext2_filsys fs, struct ext2_inode *inode, blk64_t b)
 {
-       if ((fs->super->s_feature_ro_compat &
-            EXT4_FEATURE_RO_COMPAT_HUGE_FILE) &&
-           (inode->i_flags & EXT4_HUGE_FILE_FL)) {
-               inode->i_blocks = b & 0xFFFFFFFF;
+       if (!(fs->super->s_feature_ro_compat &
+             EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
+           !(inode->i_flags & EXT4_HUGE_FILE_FL))
+               b *= fs->blocksize / 512;
+
+       inode->i_blocks = b & 0xFFFFFFFF;
+       if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
                inode->osd2.linux2.l_i_blocks_hi = b >> 32;
-       } else
-               inode->i_blocks = (fs->blocksize / 512) * b;
+       else if (b >> 32)
+               return EOVERFLOW;
        return 0;
 }