Orion
Barry Importing existing Orion kernel d41a53c (3 years, 2 months ago)
diff --git a/vfs/ext2fs/file.c b/vfs/ext2fs/file.c
new file mode 100644
index 0000000..d0caa35
--- /dev/null
+++ b/vfs/ext2fs/file.c
@@ -0,0 +1,86 @@
+/*
+ * This file controls access to Ext2FS Files. It contains the functions called
+ * by the VFS for any operation on a Ext2FS File struct.
+ */
+
+#include <stddef.h>
+#include <string.h>
+#include <dirent.h>
+#include <errno.h>
+#include "fs.h"
+#include "../vfs.h"
+
+size_t ext2fs_read(File *file, char *buf, size_t size, off_t offset);
+int ext2fs_readdir(File *file, DirEnt *dent, off_t index);
+int ext2fs_open(File *file);
+
+FileOps ext2fsFileOps = {
+ .read = ext2fs_read,
+ .readdir = ext2fs_readdir,
+ .open = ext2fs_open,
+};
+
+/* Read a file */
+size_t
+ext2fs_read(File *file, char *buf, size_t size, off_t offset)
+{
+ Ext2Inode inode;
+ uint16_t min;
+ size_t count = 0, i = offset / 4096;
+ uint32_t blk;
+ char ebuf[4096];
+ ext2_read_inode(file->inode->super, file->inode->ino, &inode);
+ if (offset > inode.lsize)
+ return 0;
+ if (size + offset > inode.lsize)
+ size = inode.lsize - offset;
+ while (size) {
+ min = (size > 0x1000) ? 0x1000 : size;
+ blk = ext2_get_data_addr(file->inode->super, &inode, i);
+ ext2_read_block(file->inode->super, blk, ebuf);
+ memcpy(buf + count, ebuf + (offset % 4096), min);
+ size -= min;
+ count += min;
+ i++;
+ }
+ if (count >= 0x1000)
+ return count;
+}
+
+/* Read a directory entry */
+int
+ext2fs_readdir(File *file, DirEnt *dent, off_t index)
+{
+ char buf[4096];
+ uint32_t block, blk = 0;
+ Ext2DirEntry *de;
+ Ext2Inode inode;
+ ext2_read_inode(file->inode->super, file->inode->ino, &inode);
+ for (blk = 0; blk < 0xFFFF; blk++) {
+ block = ext2_get_data_addr(file->inode->super, &inode, blk);
+ if (!block)
+ return -ENOENT;
+ ext2_read_block(file->inode->super, block, buf);
+ for (de = (Ext2DirEntry *) buf;
+ index && de < (Ext2DirEntry *) (buf + 4096);
+ de = (void *) ((char *) de + de->size), index--);
+ if (de >= (Ext2DirEntry *) (buf + 4096))
+ return -ENOENT;
+ if (!index)
+ break;
+ }
+ if (!de->ino)
+ return -ENOENT;
+ dent->ino = de->ino;
+ dent->type = de->type;
+ dent->namelen = de->nameLen + 1;
+ strncpy(dent->name, de->name, de->size);
+ return 0;
+}
+
+/* Open a file */
+int
+ext2fs_open(File *file)
+{
+ return 0;
+}