ext4: special inode creation support

4 files changed, 138 insertions, 9 deletions

diff --git a/src/ext4.c b/src/ext4.c
index db7745f..0f2f07a 100644
--- a/src/ext4.c
+++ b/src/ext4.c
@@ -2413,6 +2413,72 @@ Finish:
 	return r;
 }
 
+static int ext4_mknod_set(ext4_file *f, uint32_t dev)
+{
+	struct ext4_inode_ref ref;
+	int r;
+
+	ext4_assert(f && f->mp);
+
+	r = ext4_fs_get_inode_ref(&f->mp->fs, f->inode, &ref);
+	if (r != EOK)
+		return r;
+
+	ext4_inode_set_dev(ref.inode, dev);
+
+	ext4_inode_set_size(ref.inode, 0);
+	ref.dirty = true;
+
+	f->fsize = 0;
+	f->fpos = 0;
+
+	r = ext4_fs_put_inode_ref(&ref);
+	return r;
+}
+
+int ext4_mknod(const char *path, int filetype, uint32_t dev)
+{
+	struct ext4_mountpoint *mp = ext4_get_mount(path);
+	int r;
+	ext4_file f;
+
+	if (!mp)
+		return ENOENT;
+
+	if (mp->fs.read_only)
+		return EROFS;
+
+	if (filetype == EXT4_DE_UNKNOWN ||
+	    filetype == EXT4_DE_REG_FILE ||
+	    filetype == EXT4_DE_DIR)
+		return EINVAL;
+
+	EXT4_MP_LOCK(mp);
+	ext4_trans_start(mp);
+
+	ext4_block_cache_write_back(mp->fs.bdev, 1);
+	r = ext4_generic_open2(&f, path, O_RDWR|O_CREAT, filetype, NULL, NULL);
+	if (r == EOK) {
+		if (filetype == EXT4_DE_CHRDEV ||
+		    filetype == EXT4_DE_BLKDEV)
+			r = ext4_mknod_set(&f, dev);
+	} else
+		goto Finish;
+
+	ext4_fclose(&f);
+
+Finish:
+	ext4_block_cache_write_back(mp->fs.bdev, 0);
+
+	if (r != EOK)
+		ext4_trans_abort(mp);
+	else
+		ext4_trans_stop(mp);
+
+	EXT4_MP_UNLOCK(mp);
+	return r;
+}
+
 int ext4_setxattr(const char *path, const char *name, size_t name_len,
 		  const void *data, size_t data_size, bool replace __unused)
 {
diff --git a/src/ext4_dir.c b/src/ext4_dir.c
index 438d386..4836d62 100644
--- a/src/ext4_dir.c
+++ b/src/ext4_dir.c
@@ -314,9 +314,21 @@ void ext4_dir_write_entry(struct ext4_sblock *sb, struct ext4_dir_en *en,
 	case EXT4_INODE_MODE_SOFTLINK:
 		ext4_dir_en_set_inode_type(sb, en, EXT4_DE_SYMLINK);
 		break;
+	case EXT4_INODE_MODE_CHARDEV:
+		ext4_dir_en_set_inode_type(sb, en, EXT4_DE_CHRDEV);
+		break;
+	case EXT4_INODE_MODE_BLOCKDEV:
+		ext4_dir_en_set_inode_type(sb, en, EXT4_DE_BLKDEV);
+		break;
+	case EXT4_INODE_MODE_FIFO:
+		ext4_dir_en_set_inode_type(sb, en, EXT4_DE_FIFO);
+		break;
+	case EXT4_INODE_MODE_SOCKET:
+		ext4_dir_en_set_inode_type(sb, en, EXT4_DE_SOCK);
+		break;
 	default:
-		/* FIXME: right now we only support 3 inode type. */
-		ext4_assert(0);
+		/* FIXME: unsupported filetype */
+		ext4_dir_en_set_inode_type(sb, en, EXT4_DE_UNKNOWN);
 	}
 
 	/* Set basic attributes */
diff --git a/src/ext4_fs.c b/src/ext4_fs.c
index 8a0be5b..e8b296d 100644
--- a/src/ext4_fs.c
+++ b/src/ext4_fs.c
@@ -832,11 +832,17 @@ uint32_t ext4_fs_correspond_inode_mode(int filetype)
 		return EXT4_INODE_MODE_FILE;
 	case EXT4_DE_SYMLINK:
 		return EXT4_INODE_MODE_SOFTLINK;
-	default:
-		/* FIXME: right now we only support 3 file type. */
-		ext4_assert(0);
+	case EXT4_DE_CHRDEV:
+		return EXT4_INODE_MODE_CHARDEV;
+	case EXT4_DE_BLKDEV:
+		return EXT4_INODE_MODE_BLOCKDEV;
+	case EXT4_DE_FIFO:
+		return EXT4_INODE_MODE_FIFO;
+	case EXT4_DE_SOCK:
+		return EXT4_INODE_MODE_SOCKET;
 	}
-	return 0;
+	/* FIXME: unsupported filetype */
+	return EXT4_INODE_MODE_FILE;
 }
 
 int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
@@ -844,6 +850,7 @@ int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
 {
 	/* Check if newly allocated i-node will be a directory */
 	bool is_dir;
+	uint32_t type;
 	uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
 
 	is_dir = (filetype == EXT4_DE_DIR);
@@ -876,6 +883,14 @@ int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
 
 		mode = 0777;
 		mode |= EXT4_INODE_MODE_DIRECTORY;
+	} else if (filetype == EXT4_DE_SYMLINK) {
+		/*
+		 * Default symbolic link permissions to be compatible with other systems
+		 * 0777 (octal) == rwxrwxrwx
+		 */
+
+		mode = 0777;
+		mode |= EXT4_INODE_MODE_SOFTLINK;
 	} else {
 		/*
 		 * Default file permissions to be compatible with other systems
@@ -904,9 +919,13 @@ int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
 		ext4_inode_set_extra_isize(&fs->sb, inode, size);
 	}
 
-	/* Reset blocks array. For symbolic link inode, just
+	/* Reset blocks array. For inode which is not directory or file, just
 	 * fill in blocks with 0 */
-	if (ext4_inode_is_type(&fs->sb, inode, EXT4_INODE_MODE_SOFTLINK)) {
+	type = ext4_inode_type(&fs->sb, inode_ref->inode);
+	if (type == EXT4_INODE_MODE_CHARDEV ||
+	    type == EXT4_INODE_MODE_BLOCKDEV ||
+	    type == EXT4_INODE_MODE_SOCKET ||
+	    type == EXT4_INODE_MODE_SOFTLINK) {
 		for (int i = 0; i < EXT4_INODE_BLOCKS; i++)
 			inode->blocks[i] = 0;
 
@@ -1169,6 +1188,7 @@ int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
 	struct ext4_sblock *sb = &inode_ref->fs->sb;
 	uint32_t i;
 	int r;
+	bool v;
 
 	/* Check flags, if i-node can be truncated */
 	if (!ext4_inode_can_truncate(sb, inode_ref->inode))
@@ -1183,7 +1203,7 @@ int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
 	if (old_size < new_size)
 		return EINVAL;
 
-	bool v;
+	/* For symbolic link which is small enough */
 	v = ext4_inode_is_type(sb, inode_ref->inode, EXT4_INODE_MODE_SOFTLINK);
 	if (v && old_size < sizeof(inode_ref->inode->blocks) &&
 	    !ext4_inode_get_blocks_count(sb, inode_ref->inode)) {
@@ -1196,6 +1216,17 @@ int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
 		return EOK;
 	}
 
+	i = ext4_inode_type(sb, inode_ref->inode);
+	if (i == EXT4_INODE_MODE_CHARDEV ||
+	    i == EXT4_INODE_MODE_BLOCKDEV ||
+	    i == EXT4_INODE_MODE_SOCKET) {
+		inode_ref->inode->blocks[0] = 0;
+		inode_ref->inode->blocks[1] = 0;
+
+		inode_ref->dirty = true;
+		return EOK;
+	}
+
 	/* Compute how many blocks will be released */
 	uint32_t block_size = ext4_sb_get_block_size(sb);
 	uint32_t new_blocks_cnt = (uint32_t)((new_size + block_size - 1) / block_size);
diff --git a/src/ext4_inode.c b/src/ext4_inode.c
index c64ddbc..513da60 100644
--- a/src/ext4_inode.c
+++ b/src/ext4_inode.c
@@ -328,6 +328,26 @@ void ext4_inode_set_indirect_block(struct ext4_inode *inode, uint32_t idx,
 	inode->blocks[idx + EXT4_INODE_INDIRECT_BLOCK] = to_le32(block);
 }
 
+uint32_t ext4_inode_get_dev(struct ext4_inode *inode)
+{
+	uint32_t dev_0, dev_1;
+	dev_0 = ext4_inode_get_direct_block(inode, 0);
+	dev_1 = ext4_inode_get_direct_block(inode, 1);
+
+	if (dev_0)
+		return dev_0;
+	else
+		return dev_1;
+}
+
+void ext4_inode_set_dev(struct ext4_inode *inode, uint32_t dev)
+{
+	if (dev & ~0xFFFF)
+		ext4_inode_set_direct_block(inode, 1, dev);
+	else
+		ext4_inode_set_direct_block(inode, 0, dev);
+}
+
 uint32_t ext4_inode_type(struct ext4_sblock *sb, struct ext4_inode *inode)
 {
 	return (ext4_inode_get_mode(sb, inode) & EXT4_INODE_MODE_TYPE_MASK);