ext4: fix big-endian bugs which could cause fs corruptions

When an extent was zeroed out, we forgot to do convert from cpu to le16. It could make us hit a BUG_ON when we try to write dirty pages out. So fix it. [ Also fix a bug found by Dmitry Monakhov where we were missing le32_to_cpu() calls in the new indirect punch hole code. There are a number of other big endian warnings found by static code analyzers, but we'll wait for the next merge window to fix them all up. These fixes are designed to be Obviously Correct by code inspection, and easy to demonstrate that it won't make any difference (and hence, won't introduce any bugs) on little endian architectures such as x86. --tytso ] Signed-off-by: Zheng Liu <[email protected]> Signed-off-by: "Theodore Ts'o" <[email protected]> Reported-by: CAI Qian <[email protected]> Reported-by: Christian Kujau <[email protected]> Cc: Dmitry Monakhov <[email protected]>
progmanos · Apr 3, 2013 · 8cde7ad · 8cde7ad
1 parent 07961ac
commit 8cde7ad
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Showing 2 changed files with 9 additions and 6 deletions.
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
@@ -2999,20 +2999,23 @@ static int ext4_split_extent_at(handle_t *handle,
 			if (split_flag & EXT4_EXT_DATA_VALID1) {
 				err = ext4_ext_zeroout(inode, ex2);
 				zero_ex.ee_block = ex2->ee_block;
-				zero_ex.ee_len = ext4_ext_get_actual_len(ex2);
+				zero_ex.ee_len = cpu_to_le16(
+						ext4_ext_get_actual_len(ex2));
 				ext4_ext_store_pblock(&zero_ex,
 						      ext4_ext_pblock(ex2));
 			} else {
 				err = ext4_ext_zeroout(inode, ex);
 				zero_ex.ee_block = ex->ee_block;
-				zero_ex.ee_len = ext4_ext_get_actual_len(ex);
+				zero_ex.ee_len = cpu_to_le16(
+						ext4_ext_get_actual_len(ex));
 				ext4_ext_store_pblock(&zero_ex,
 						      ext4_ext_pblock(ex));
 			}
 		} else {
 			err = ext4_ext_zeroout(inode, &orig_ex);
 			zero_ex.ee_block = orig_ex.ee_block;
-			zero_ex.ee_len = ext4_ext_get_actual_len(&orig_ex);
+			zero_ex.ee_len = cpu_to_le16(
+						ext4_ext_get_actual_len(&orig_ex));
 			ext4_ext_store_pblock(&zero_ex,
 					      ext4_ext_pblock(&orig_ex));
 		}
@@ -3272,7 +3275,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 		if (err)
 			goto out;
 		zero_ex.ee_block = ex->ee_block;
-		zero_ex.ee_len = ext4_ext_get_actual_len(ex);
+		zero_ex.ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex));
 		ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex));
 
 		err = ext4_ext_get_access(handle, inode, path + depth);

diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
@@ -1539,9 +1539,9 @@ static int free_hole_blocks(handle_t *handle, struct inode *inode,
 		blk = *i_data;
 		if (level > 0) {
 			ext4_lblk_t first2;
-			bh = sb_bread(inode->i_sb, blk);
+			bh = sb_bread(inode->i_sb, le32_to_cpu(blk));
 			if (!bh) {
-				EXT4_ERROR_INODE_BLOCK(inode, blk,
+				EXT4_ERROR_INODE_BLOCK(inode, le32_to_cpu(blk),
 						       "Read failure");
 				return -EIO;
 			}