X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=fs%2Fext4%2Fnamei.c;h=94ee6f315dc17580c6de82f65d3f58735a29b870;hb=d8c89eb3a12f0da96d049bd515c7fa3702e511c5;hp=da224974af7861efeab66cdd0de475e0679f9432;hpb=532df780a2012ad75b3f078647f229c4dabd99d1;p=linux-2.6-omap-h63xx.git

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index da224974af7..94ee6f315dc 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -140,10 +140,10 @@ struct dx_frame
 struct dx_map_entry
 {
 	u32 hash;
-	u32 offs;
+	u16 offs;
+	u16 size;
 };
 
-#ifdef CONFIG_EXT4_INDEX
 static inline unsigned dx_get_block (struct dx_entry *entry);
 static void dx_set_block (struct dx_entry *entry, unsigned value);
 static inline unsigned dx_get_hash (struct dx_entry *entry);
@@ -379,13 +379,28 @@ dx_probe(struct dentry *dentry, struct inode *dir,
 
 	entries = (struct dx_entry *) (((char *)&root->info) +
 				       root->info.info_length);
-	assert(dx_get_limit(entries) == dx_root_limit(dir,
-						      root->info.info_length));
+
+	if (dx_get_limit(entries) != dx_root_limit(dir,
+						   root->info.info_length)) {
+		ext4_warning(dir->i_sb, __FUNCTION__,
+			     "dx entry: limit != root limit");
+		brelse(bh);
+		*err = ERR_BAD_DX_DIR;
+		goto fail;
+	}
+
 	dxtrace (printk("Look up %x", hash));
 	while (1)
 	{
 		count = dx_get_count(entries);
-		assert (count && count <= dx_get_limit(entries));
+		if (!count || count > dx_get_limit(entries)) {
+			ext4_warning(dir->i_sb, __FUNCTION__,
+				     "dx entry: no count or count > limit");
+			brelse(bh);
+			*err = ERR_BAD_DX_DIR;
+			goto fail2;
+		}
+
 		p = entries + 1;
 		q = entries + count - 1;
 		while (p <= q)
@@ -423,8 +438,15 @@ dx_probe(struct dentry *dentry, struct inode *dir,
 		if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
 			goto fail2;
 		at = entries = ((struct dx_node *) bh->b_data)->entries;
-		assert (dx_get_limit(entries) == dx_node_limit (dir));
+		if (dx_get_limit(entries) != dx_node_limit (dir)) {
+			ext4_warning(dir->i_sb, __FUNCTION__,
+				     "dx entry: limit != node limit");
+			brelse(bh);
+			*err = ERR_BAD_DX_DIR;
+			goto fail2;
+		}
 		frame++;
+		frame->bh = NULL;
 	}
 fail2:
 	while (frame >= frame_in) {
@@ -432,6 +454,10 @@ fail2:
 		frame--;
 	}
 fail:
+	if (*err == ERR_BAD_DX_DIR)
+		ext4_warning(dir->i_sb, __FUNCTION__,
+			     "Corrupt dir inode %ld, running e2fsck is "
+			     "recommended.", dir->i_ino);
 	return NULL;
 }
 
@@ -671,6 +697,10 @@ errout:
  * Directory block splitting, compacting
  */
 
+/*
+ * Create map of hash values, offsets, and sizes, stored at end of block.
+ * Returns number of entries mapped.
+ */
 static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
 			struct dx_hash_info *hinfo, struct dx_map_entry *map_tail)
 {
@@ -684,7 +714,8 @@ static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
 			ext4fs_dirhash(de->name, de->name_len, &h);
 			map_tail--;
 			map_tail->hash = h.hash;
-			map_tail->offs = (u32) ((char *) de - base);
+			map_tail->offs = (u16) ((char *) de - base);
+			map_tail->size = le16_to_cpu(de->rec_len);
 			count++;
 			cond_resched();
 		}
@@ -694,6 +725,7 @@ static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
 	return count;
 }
 
+/* Sort map by hash value */
 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
 {
 	struct dx_map_entry *p, *q, *top = map + count - 1;
@@ -733,8 +765,6 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, u32 block)
 	dx_set_block(new, block);
 	dx_set_count(entries, count + 1);
 }
-#endif
-
 
 static void ext4_update_dx_flag(struct inode *inode)
 {
@@ -836,7 +866,6 @@ static struct buffer_head * ext4_find_entry (struct dentry *dentry,
 	name = dentry->d_name.name;
 	if (namelen > EXT4_NAME_LEN)
 		return NULL;
-#ifdef CONFIG_EXT4_INDEX
 	if (is_dx(dir)) {
 		bh = ext4_dx_find_entry(dentry, res_dir, &err);
 		/*
@@ -848,7 +877,6 @@ static struct buffer_head * ext4_find_entry (struct dentry *dentry,
 			return bh;
 		dxtrace(printk("ext4_find_entry: dx failed, falling back\n"));
 	}
-#endif
 	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
 	start = EXT4_I(dir)->i_dir_start_lookup;
 	if (start >= nblocks)
@@ -924,7 +952,6 @@ cleanup_and_exit:
 	return ret;
 }
 
-#ifdef CONFIG_EXT4_INDEX
 static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
 		       struct ext4_dir_entry_2 **res_dir, int *err)
 {
@@ -992,7 +1019,6 @@ errout:
 	dx_release (frames);
 	return NULL;
 }
-#endif
 
 static struct dentry *ext4_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
 {
@@ -1088,7 +1114,10 @@ static inline void ext4_set_de_type(struct super_block *sb,
 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
 }
 
-#ifdef CONFIG_EXT4_INDEX
+/*
+ * Move count entries from end of map between two memory locations.
+ * Returns pointer to last entry moved.
+ */
 static struct ext4_dir_entry_2 *
 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
 {
@@ -1107,6 +1136,10 @@ dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
 	return (struct ext4_dir_entry_2 *) (to - rec_len);
 }
 
+/*
+ * Compact each dir entry in the range to the minimal rec_len.
+ * Returns pointer to last entry in range.
+ */
 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size)
 {
 	struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
@@ -1129,6 +1162,11 @@ static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size)
 	return prev;
 }
 
+/*
+ * Split a full leaf block to make room for a new dir entry.
+ * Allocate a new block, and move entries so that they are approx. equally full.
+ * Returns pointer to de in block into which the new entry will be inserted.
+ */
 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 			struct buffer_head **bh,struct dx_frame *frame,
 			struct dx_hash_info *hinfo, int *error)
@@ -1140,7 +1178,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	u32 hash2;
 	struct dx_map_entry *map;
 	char *data1 = (*bh)->b_data, *data2;
-	unsigned split;
+	unsigned split, move, size, i;
 	struct ext4_dir_entry_2 *de = NULL, *de2;
 	int	err = 0;
 
@@ -1168,8 +1206,19 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	count = dx_make_map ((struct ext4_dir_entry_2 *) data1,
 			     blocksize, hinfo, map);
 	map -= count;
-	split = count/2; // need to adjust to actual middle
 	dx_sort_map (map, count);
+	/* Split the existing block in the middle, size-wise */
+	size = 0;
+	move = 0;
+	for (i = count-1; i >= 0; i--) {
+		/* is more than half of this entry in 2nd half of the block? */
+		if (size + map[i].size/2 > blocksize/2)
+			break;
+		size += map[i].size;
+		move++;
+	}
+	/* map index at which we will split */
+	split = count - move;
 	hash2 = map[split].hash;
 	continued = hash2 == map[split - 1].hash;
 	dxtrace(printk("Split block %i at %x, %i/%i\n",
@@ -1209,8 +1258,6 @@ errout:
 	*error = err;
 	return NULL;
 }
-#endif
-
 
 /*
  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
@@ -1307,7 +1354,6 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 	return 0;
 }
 
-#ifdef CONFIG_EXT4_INDEX
 /*
  * This converts a one block unindexed directory to a 3 block indexed
  * directory, and adds the dentry to the indexed directory.
@@ -1386,7 +1432,6 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 
 	return add_dirent_to_buf(handle, dentry, inode, de, bh);
 }
-#endif
 
 /*
  *	ext4_add_entry()
@@ -1407,9 +1452,7 @@ static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
 	struct ext4_dir_entry_2 *de;
 	struct super_block * sb;
 	int	retval;
-#ifdef CONFIG_EXT4_INDEX
 	int	dx_fallback=0;
-#endif
 	unsigned blocksize;
 	u32 block, blocks;
 
@@ -1417,7 +1460,6 @@ static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
 	blocksize = sb->s_blocksize;
 	if (!dentry->d_name.len)
 		return -EINVAL;
-#ifdef CONFIG_EXT4_INDEX
 	if (is_dx(dir)) {
 		retval = ext4_dx_add_entry(handle, dentry, inode);
 		if (!retval || (retval != ERR_BAD_DX_DIR))
@@ -1426,7 +1468,6 @@ static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
 		dx_fallback++;
 		ext4_mark_inode_dirty(handle, dir);
 	}
-#endif
 	blocks = dir->i_size >> sb->s_blocksize_bits;
 	for (block = 0, offset = 0; block < blocks; block++) {
 		bh = ext4_bread(handle, dir, block, 0, &retval);
@@ -1436,11 +1477,9 @@ static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
 		if (retval != -ENOSPC)
 			return retval;
 
-#ifdef CONFIG_EXT4_INDEX
 		if (blocks == 1 && !dx_fallback &&
 		    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
 			return make_indexed_dir(handle, dentry, inode, bh);
-#endif
 		brelse(bh);
 	}
 	bh = ext4_append(handle, dir, &block, &retval);
@@ -1452,7 +1491,6 @@ static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
 	return add_dirent_to_buf(handle, dentry, inode, de, bh);
 }
 
-#ifdef CONFIG_EXT4_INDEX
 /*
  * Returns 0 for success, or a negative error value
  */
@@ -1587,7 +1625,6 @@ cleanup:
 	dx_release(frames);
 	return err;
 }
-#endif
 
 /*
  * ext4_delete_entry deletes a directory entry by merging it with the