1 files changed, 121 insertions, 39 deletions

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index f10307215d58..87c6d619a564 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -54,6 +54,7 @@ static struct buffer_head *ext4_append(handle_t *handle,
 					struct inode *inode,
 					ext4_lblk_t *block)
 {
+	struct ext4_map_blocks map;
 	struct buffer_head *bh;
 	int err;
 
@@ -63,6 +64,21 @@ static struct buffer_head *ext4_append(handle_t *handle,
 		return ERR_PTR(-ENOSPC);
 
 	*block = inode->i_size >> inode->i_sb->s_blocksize_bits;
+	map.m_lblk = *block;
+	map.m_len = 1;
+
+	/*
+	 * We're appending new directory block. Make sure the block is not
+	 * allocated yet, otherwise we will end up corrupting the
+	 * directory.
+	 */
+	err = ext4_map_blocks(NULL, inode, &map, 0);
+	if (err < 0)
+		return ERR_PTR(err);
+	if (err) {
+		EXT4_ERROR_INODE(inode, "Logical block already allocated");
+		return ERR_PTR(-EFSCORRUPTED);
+	}
 
 	bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
 	if (IS_ERR(bh))
@@ -273,9 +289,9 @@ static struct dx_frame *dx_probe(struct ext4_filename *fname,
 				 struct dx_hash_info *hinfo,
 				 struct dx_frame *frame);
 static void dx_release(struct dx_frame *frames);
-static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
-		       unsigned blocksize, struct dx_hash_info *hinfo,
-		       struct dx_map_entry map[]);
+static int dx_make_map(struct inode *dir, struct buffer_head *bh,
+		       struct dx_hash_info *hinfo,
+		       struct dx_map_entry *map_tail);
 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 		struct dx_map_entry *offsets, int count, unsigned blocksize);
@@ -309,17 +325,17 @@ static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 						   struct buffer_head *bh)
 {
 	struct ext4_dir_entry_tail *t;
+	int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
 
 #ifdef PARANOID
 	struct ext4_dir_entry *d, *top;
 
 	d = (struct ext4_dir_entry *)bh->b_data;
 	top = (struct ext4_dir_entry *)(bh->b_data +
-		(EXT4_BLOCK_SIZE(inode->i_sb) -
-		 sizeof(struct ext4_dir_entry_tail)));
-	while (d < top && d->rec_len)
+		(blocksize - sizeof(struct ext4_dir_entry_tail)));
+	while (d < top && ext4_rec_len_from_disk(d->rec_len, blocksize))
 		d = (struct ext4_dir_entry *)(((void *)d) +
-		    le16_to_cpu(d->rec_len));
+		    ext4_rec_len_from_disk(d->rec_len, blocksize));
 
 	if (d != top)
 		return NULL;
@@ -330,7 +346,8 @@ static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 #endif
 
 	if (t->det_reserved_zero1 ||
-	    le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
+	    (ext4_rec_len_from_disk(t->det_rec_len, blocksize) !=
+	     sizeof(struct ext4_dir_entry_tail)) ||
 	    t->det_reserved_zero2 ||
 	    t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 		return NULL;
@@ -411,13 +428,14 @@ static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 	struct ext4_dir_entry *dp;
 	struct dx_root_info *root;
 	int count_offset;
+	int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
+	unsigned int rlen = ext4_rec_len_from_disk(dirent->rec_len, blocksize);
 
-	if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
+	if (rlen == blocksize)
 		count_offset = 8;
-	else if (le16_to_cpu(dirent->rec_len) == 12) {
+	else if (rlen == 12) {
 		dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
-		if (le16_to_cpu(dp->rec_len) !=
-		    EXT4_BLOCK_SIZE(inode->i_sb) - 12)
+		if (ext4_rec_len_from_disk(dp->rec_len, blocksize) != blocksize - 12)
 			return NULL;
 		root = (struct dx_root_info *)(((void *)dp + 12));
 		if (root->reserved_zero ||
@@ -750,12 +768,14 @@ static struct dx_frame *
 dx_probe(struct ext4_filename *fname, struct inode *dir,
 	 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 {
-	unsigned count, indirect;
+	unsigned count, indirect, level, i;
 	struct dx_entry *at, *entries, *p, *q, *m;
 	struct dx_root *root;
 	struct dx_frame *frame = frame_in;
 	struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 	u32 hash;
+	ext4_lblk_t block;
+	ext4_lblk_t blocks[EXT4_HTREE_LEVEL];
 
 	memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
 	frame->bh = ext4_read_dirblock(dir, 0, INDEX);
@@ -811,6 +831,8 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
 	}
 
 	dxtrace(printk("Look up %x", hash));
+	level = 0;
+	blocks[0] = 0;
 	while (1) {
 		count = dx_get_count(entries);
 		if (!count || count > dx_get_limit(entries)) {
@@ -852,15 +874,27 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
 			       dx_get_block(at)));
 		frame->entries = entries;
 		frame->at = at;
-		if (!indirect--)
+
+		block = dx_get_block(at);
+		for (i = 0; i <= level; i++) {
+			if (blocks[i] == block) {
+				ext4_warning_inode(dir,
+					"dx entry: tree cycle block %u points back to block %u",
+					blocks[level], block);
+				goto fail;
+			}
+		}
+		if (++level > indirect)
 			return frame;
+		blocks[level] = block;
 		frame++;
-		frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
+		frame->bh = ext4_read_dirblock(dir, block, INDEX);
 		if (IS_ERR(frame->bh)) {
 			ret_err = (struct dx_frame *) frame->bh;
 			frame->bh = NULL;
 			goto fail;
 		}
+
 		entries = ((struct dx_node *) frame->bh->b_data)->entries;
 
 		if (dx_get_limit(entries) != dx_node_limit(dir)) {
@@ -1205,25 +1239,34 @@ static inline int search_dirblock(struct buffer_head *bh,
  * Create map of hash values, offsets, and sizes, stored at end of block.
  * Returns number of entries mapped.
  */
-static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
-		       unsigned blocksize, struct dx_hash_info *hinfo,
+static int dx_make_map(struct inode *dir, struct buffer_head *bh,
+		       struct dx_hash_info *hinfo,
 		       struct dx_map_entry *map_tail)
 {
 	int count = 0;
-	char *base = (char *) de;
+	struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data;
+	unsigned int buflen = bh->b_size;
+	char *base = bh->b_data;
 	struct dx_hash_info h = *hinfo;
+	int blocksize = EXT4_BLOCK_SIZE(dir->i_sb);
+
+	if (ext4_has_metadata_csum(dir->i_sb))
+		buflen -= sizeof(struct ext4_dir_entry_tail);
 
-	while ((char *) de < base + blocksize) {
+	while ((char *) de < base + buflen) {
+		if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen,
+					 ((char *)de) - base))
+			return -EFSCORRUPTED;
 		if (de->name_len && de->inode) {
 			ext4fs_dirhash(dir, de->name, de->name_len, &h);
 			map_tail--;
 			map_tail->hash = h.hash;
 			map_tail->offs = ((char *) de - base)>>2;
-			map_tail->size = le16_to_cpu(de->rec_len);
+			map_tail->size = ext4_rec_len_from_disk(de->rec_len,
+								blocksize);
 			count++;
 			cond_resched();
 		}
-		/* XXX: do we need to check rec_len == 0 case? -Chris */
 		de = ext4_next_entry(de, blocksize);
 	}
 	return count;
@@ -1463,11 +1506,10 @@ static struct buffer_head *__ext4_find_entry(struct inode *dir,
 		int has_inline_data = 1;
 		ret = ext4_find_inline_entry(dir, fname, res_dir,
 					     &has_inline_data);
-		if (has_inline_data) {
-			if (inlined)
-				*inlined = 1;
+		if (inlined)
+			*inlined = has_inline_data;
+		if (has_inline_data)
 			goto cleanup_and_exit;
-		}
 	}
 
 	if ((namelen <= 2) && (name[0] == '.') &&
@@ -1813,7 +1855,8 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 			struct dx_hash_info *hinfo)
 {
 	unsigned blocksize = dir->i_sb->s_blocksize;
-	unsigned count, continued;
+	unsigned continued;
+	int count;
 	struct buffer_head *bh2;
 	ext4_lblk_t newblock;
 	u32 hash2;
@@ -1848,8 +1891,11 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 
 	/* create map in the end of data2 block */
 	map = (struct dx_map_entry *) (data2 + blocksize);
-	count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
-			     blocksize, hinfo, map);
+	count = dx_make_map(dir, *bh, hinfo, map);
+	if (count < 0) {
+		err = count;
+		goto journal_error;
+	}
 	map -= count;
 	dx_sort_map(map, count);
 	/* Ensure that neither split block is over half full */
@@ -2098,8 +2144,16 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
 	memcpy(data2, de, len);
 	de = (struct ext4_dir_entry_2 *) data2;
 	top = data2 + len;
-	while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
+	while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) {
+		if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len,
+					 (data2 + (blocksize - csum_size) -
+					  (char *) de))) {
+			brelse(bh2);
+			brelse(bh);
+			return -EFSCORRUPTED;
+		}
 		de = de2;
+	}
 	de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
 					   (char *) de, blocksize);
 
@@ -2886,11 +2940,8 @@ bool ext4_empty_dir(struct inode *inode)
 		de = (struct ext4_dir_entry_2 *) (bh->b_data +
 					(offset & (sb->s_blocksize - 1)));
 		if (ext4_check_dir_entry(inode, NULL, de, bh,
-					 bh->b_data, bh->b_size, offset)) {
-			offset = (offset | (sb->s_blocksize - 1)) + 1;
-			continue;
-		}
-		if (le32_to_cpu(de->inode)) {
+					 bh->b_data, bh->b_size, offset) ||
+		    le32_to_cpu(de->inode)) {
 			brelse(bh);
 			return false;
 		}
@@ -3442,6 +3493,9 @@ static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
 	struct buffer_head *bh;
 
 	if (!ext4_has_inline_data(inode)) {
+		struct ext4_dir_entry_2 *de;
+		unsigned int offset;
+
 		/* The first directory block must not be a hole, so
 		 * treat it as DIRENT_HTREE
 		 */
@@ -3450,9 +3504,30 @@ static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
 			*retval = PTR_ERR(bh);
 			return NULL;
 		}
-		*parent_de = ext4_next_entry(
-					(struct ext4_dir_entry_2 *)bh->b_data,
-					inode->i_sb->s_blocksize);
+
+		de = (struct ext4_dir_entry_2 *) bh->b_data;
+		if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
+					 bh->b_size, 0) ||
+		    le32_to_cpu(de->inode) != inode->i_ino ||
+		    strcmp(".", de->name)) {
+			EXT4_ERROR_INODE(inode, "directory missing '.'");
+			brelse(bh);
+			*retval = -EFSCORRUPTED;
+			return NULL;
+		}
+		offset = ext4_rec_len_from_disk(de->rec_len,
+						inode->i_sb->s_blocksize);
+		de = ext4_next_entry(de, inode->i_sb->s_blocksize);
+		if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
+					 bh->b_size, offset) ||
+		    le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
+			EXT4_ERROR_INODE(inode, "directory missing '..'");
+			brelse(bh);
+			*retval = -EFSCORRUPTED;
+			return NULL;
+		}
+		*parent_de = de;
+
 		return bh;
 	}
 
@@ -3558,7 +3633,8 @@ static void ext4_resetent(handle_t *handle, struct ext4_renament *ent,
 	 * so the old->de may no longer valid and need to find it again
 	 * before reset old inode info.
 	 */
-	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
+	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de,
+				 &old.inlined);
 	if (IS_ERR(old.bh))
 		retval = PTR_ERR(old.bh);
 	if (!old.bh)
@@ -3708,6 +3784,9 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 	retval = dquot_initialize(old.dir);
 	if (retval)
 		return retval;
+	retval = dquot_initialize(old.inode);
+	if (retval)
+		return retval;
 	retval = dquot_initialize(new.dir);
 	if (retval)
 		return retval;
@@ -3720,9 +3799,11 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 			return retval;
 	}
 
-	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
+	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de,
+				 &old.inlined);
 	if (IS_ERR(old.bh))
 		return PTR_ERR(old.bh);
+
 	/*
 	 *  Check for inode number is _not_ due to possible IO errors.
 	 *  We might rmdir the source, keep it as pwd of some process
@@ -3881,6 +3962,7 @@ release_bh:
 	brelse(old.dir_bh);
 	brelse(old.bh);
 	brelse(new.bh);
+
 	return retval;
 }