patch-2.3.2 linux/fs/efs/dir.c

• Lines: 140
• Date: Thu May 13 23:50:15 1999
• Orig file: v2.3.1/linux/fs/efs/dir.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.1/linux/fs/efs/dir.c linux/fs/efs/dir.c
@@ -0,0 +1,139 @@
+/*
+ * dir.c
+ *
+ * Copyright (c) 1999 Al Smith
+ */
+
+#include <linux/efs_fs.h>
+
+static int efs_readdir(struct file *, void *, filldir_t);
+
+static struct file_operations efs_dir_operations = {
+	NULL,			/* lseek */
+	NULL,			/* read */
+	NULL,			/* write */
+	efs_readdir,		/* readdir */
+	NULL,			/* poll */
+	NULL,			/* ioctl */
+	NULL,			/* mmap */
+	NULL,			/* open */
+	NULL,			/* flush */
+	NULL,			/* release */
+	NULL,			/* fsync */
+	NULL,			/* fasync */
+	NULL,			/* check_media_change */
+	NULL			/* revalidate */
+};
+
+struct inode_operations efs_dir_inode_operations = {
+	&efs_dir_operations,	/* default directory file-ops */
+	NULL,			/* create */
+	efs_lookup,		/* lookup */
+	NULL,			/* link */
+	NULL,			/* unlink */
+	NULL,			/* symlink */
+	NULL,			/* mkdir */
+	NULL,			/* rmdir */
+	NULL,			/* mknod */
+	NULL,			/* rename */
+	NULL,			/* readlink */
+	NULL,			/* follow_link */
+	NULL,			/* readpage */
+	NULL,			/* writepage */
+	efs_bmap,		/* bmap */
+	NULL,			/* truncate */
+	NULL,			/* permission */
+	NULL			/* smap */
+};
+
+static int efs_readdir(struct file *filp, void *dirent, filldir_t filldir) {
+	struct inode *inode = filp->f_dentry->d_inode;
+	struct buffer_head *bh;
+
+	struct efs_dir		*dirblock;
+	struct efs_dentry	*dirslot;
+	efs_ino_t		inodenum;
+	efs_block_t		block;
+	int			slot, namelen;
+	char			*nameptr;
+
+	if (!inode || !S_ISDIR(inode->i_mode))
+		return -EBADF;
+
+	if (inode->i_size & (EFS_DIRBSIZE-1))
+		printk(KERN_WARNING "EFS: WARNING: readdir(): directory size not a multiple of EFS_DIRBSIZE\n");
+
+	/* work out where this entry can be found */
+	block = filp->f_pos >> EFS_DIRBSIZE_BITS;
+
+	/* each block contains at most 256 slots */
+	slot  = filp->f_pos & 0xff;
+
+	/* look at all blocks */
+	while (block < inode->i_blocks) {
+		/* read the dir block */
+		bh = bread(inode->i_dev, efs_bmap(inode, block), EFS_DIRBSIZE);
+
+		if (!bh) {
+			printk(KERN_ERR "EFS: readdir(): failed to read dir block %d\n", block);
+			break;
+		}
+
+		dirblock = (struct efs_dir *) bh->b_data; 
+
+		if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
+			printk(KERN_ERR "EFS: readdir(): invalid directory block\n");
+			brelse(bh);
+			break;
+		}
+
+		while (slot < dirblock->slots) {
+			if (dirblock->space[slot] == 0) {
+				slot++;
+				continue;
+			}
+
+			dirslot  = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
+
+			inodenum = be32_to_cpu(dirslot->inode);
+			namelen  = dirslot->namelen;
+			nameptr  = dirslot->name;
+
+#ifdef DEBUG
+			printk(KERN_DEBUG "EFS: readdir(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n", block, slot, dirblock->slots-1, inodenum, nameptr, namelen);
+#endif
+			if (namelen > 0) {
+				/* found the next entry */
+				filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
+
+				/* copy filename and data in dirslot */
+				filldir(dirent, nameptr, namelen, filp->f_pos, inodenum);
+
+				/* sanity check */
+				if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {
+					printk(KERN_WARNING "EFS: directory entry %d exceeds directory block\n", slot);
+					slot++;
+					continue;
+				}
+
+				/* store position of next slot */
+				if (++slot == dirblock->slots) {
+					slot = 0;
+					block++;
+				}
+				brelse(bh);
+				filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
+				return 0;
+			}
+			slot++;
+		}
+		brelse(bh);
+
+		slot = 0;
+		block++;
+	}
+
+	filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
+	return 0;
+}
+