5 files changed, 31 insertions, 8 deletions

diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index 464c33d0d7..5bf78b530a 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -570,7 +570,7 @@ restart_read:
 				g_parent_inode->size = cpu_to_le32(new_size);
 
 				new_blockcnt = le32_to_cpu(g_parent_inode->blockcnt);
-				new_blockcnt += fs->sect_perblk;
+				new_blockcnt += fs->blksz >> LOG2_SECTOR_SIZE;
 				g_parent_inode->blockcnt = cpu_to_le32(new_blockcnt);
 
 				if (ext4fs_put_metadata
@@ -1571,8 +1571,12 @@ static int ext4fs_blockgroup
 	int log2blksz = get_fs()->dev_desc->log2blksz;
 	int desc_size = get_fs()->gdsize;
 
+	if (desc_size == 0)
+		return 0;
 	desc_per_blk = EXT2_BLOCK_SIZE(data) / desc_size;
 
+	if (desc_per_blk == 0)
+		return 0;
 	blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
 			group / desc_per_blk;
 	blkoff = (group % desc_per_blk) * desc_size;
@@ -1602,6 +1606,10 @@ int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
 
 	/* It is easier to calculate if the first inode is 0. */
 	ino--;
+	if ( le32_to_cpu(sblock->inodes_per_group) == 0 || fs->inodesz == 0) {
+		free(blkgrp);
+		return 0;
+	}
 	status = ext4fs_blockgroup(data, ino / le32_to_cpu
 				   (sblock->inodes_per_group), blkgrp);
 	if (status == 0) {
@@ -1610,6 +1618,10 @@ int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
 	}
 
 	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
+	if ( inodes_per_block == 0 ) {
+		free(blkgrp);
+		return 0;
+	}
 	blkno = ext4fs_bg_get_inode_table_id(blkgrp, fs) +
 	    (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
 	blkoff = (ino % inodes_per_block) * fs->inodesz;
diff --git a/fs/ext4/ext4_journal.c b/fs/ext4/ext4_journal.c
index 6adbab93a6..3559daf11d 100644
--- a/fs/ext4/ext4_journal.c
+++ b/fs/ext4/ext4_journal.c
@@ -645,6 +645,10 @@ void ext4fs_update_journal(void)
 	struct ext_filesystem *fs = get_fs();
 	long int blknr;
 	int i;
+
+	if (!(fs->sb->feature_compatibility & EXT4_FEATURE_COMPAT_HAS_JOURNAL))
+		return;
+
 	ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO, &inode_journal);
 	blknr = read_allocated_block(&inode_journal, jrnl_blk_idx++, NULL);
 	update_descriptor_block(blknr);
diff --git a/fs/ext4/ext4_journal.h b/fs/ext4/ext4_journal.h
index c9cf195f33..43fb8e7664 100644
--- a/fs/ext4/ext4_journal.h
+++ b/fs/ext4/ext4_journal.h
@@ -17,6 +17,8 @@
 #ifndef __EXT4_JRNL__
 #define __EXT4_JRNL__
 
+#define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
+
 #define EXT2_JOURNAL_INO		8	/* Journal inode */
 #define EXT2_JOURNAL_SUPERBLOCK	0	/* Journal  Superblock number */
 
diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c
index 504d23a895..3368bd8c00 100644
--- a/fs/ext4/ext4_write.c
+++ b/fs/ext4/ext4_write.c
@@ -957,7 +957,7 @@ int ext4fs_write(const char *fname, const char *buffer,
 	ext4fs_allocate_blocks(file_inode, blocks_remaining,
 			       &blks_reqd_for_file);
 	file_inode->blockcnt = cpu_to_le32((blks_reqd_for_file * fs->blksz) >>
-		fs->dev_desc->log2blksz);
+					   LOG2_SECTOR_SIZE);
 
 	temp_ptr = zalloc(fs->blksz);
 	if (!temp_ptr)
diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
index 26db677a1f..37b31d9f0f 100644
--- a/fs/ext4/ext4fs.c
+++ b/fs/ext4/ext4fs.c
@@ -61,18 +61,21 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
 	lbaint_t delayed_skipfirst = 0;
 	lbaint_t delayed_next = 0;
 	char *delayed_buf = NULL;
+	char *start_buf = buf;
 	short status;
 	struct ext_block_cache cache;
 
 	ext_cache_init(&cache);
 
-	if (blocksize <= 0)
-		return -1;
-
 	/* Adjust len so it we can't read past the end of the file. */
 	if (len + pos > filesize)
 		len = (filesize - pos);
 
+	if (blocksize <= 0 || len <= 0) {
+		ext_cache_fini(&cache);
+		return -1;
+	}
+
 	blockcnt = lldiv(((len + pos) + blocksize - 1), blocksize);
 
 	for (i = lldiv(pos, blocksize); i < blockcnt; i++) {
@@ -137,6 +140,7 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
 			}
 		} else {
 			int n;
+			int n_left;
 			if (previous_block_number != -1) {
 				/* spill */
 				status = ext4fs_devread(delayed_start,
@@ -151,8 +155,9 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
 			}
 			/* Zero no more than `len' bytes. */
 			n = blocksize - skipfirst;
-			if (n > len)
-				n = len;
+			n_left = len - ( buf - start_buf );
+			if (n > n_left)
+				n = n_left;
 			memset(buf, 0, n);
 		}
 		buf += blocksize - skipfirst;
@@ -286,7 +291,7 @@ int ext_cache_read(struct ext_block_cache *cache, lbaint_t block, int size)
 	if (!cache->buf)
 		return 0;
 	if (!ext4fs_devread(block, 0, size, cache->buf)) {
-		free(cache->buf);
+		ext_cache_fini(cache);
 		return 0;
 	}
 	cache->block = block;