EFS integration (read-only, slight problem with symlinks).

9 files changed, 1158 insertions, 0 deletions

diff --git a/fs/Config.in b/fs/Config.in
index bb5b843cc..5f53913ee 100644
--- a/fs/Config.in
+++ b/fs/Config.in
@@ -60,6 +60,9 @@ if [ "$CONFIG_UFS_FS" != "n" ]; then
   bool 'BSD disklabel (FreeBSD partition tables) support' CONFIG_BSD_DISKLABEL
   bool 'SMD disklabel (Sun partition tables) support' CONFIG_SMD_DISKLABEL
 fi
+if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
+  tristate 'SGI EFS filesystem support' CONFIG_EFS_FS
+fi
 bool 'Macintosh partition map support' CONFIG_MAC_PARTITION
 endmenu
 
diff --git a/fs/Makefile b/fs/Makefile
index fb9da7124..6061adad6 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -182,6 +182,14 @@ else
   endif
 endif
 
+ifeq ($(CONFIG_EFS_FS),y)
+SUB_DIRS += efs
+else
+  ifeq ($(CONFIG_EFS_FS),m)
+  MOD_SUB_DIRS += efs
+  endif
+endif
+
 ifeq ($(CONFIG_BINFMT_ELF),y)
 BINFMTS += binfmt_elf.o
 else
diff --git a/fs/efs/Makefile b/fs/efs/Makefile
new file mode 100644
index 000000000..049456899
--- /dev/null
+++ b/fs/efs/Makefile
@@ -0,0 +1,17 @@
+#
+# Makefile for the linux efs-filesystem routines.
+#
+# Note! Dependencies are done automagically by 'make dep', which also
+# removes any old dependencies. DON'T put your own dependencies here
+# unless it's something special (ie not a .c file).
+#
+# Note 2! The CFLAGS definitions are now in the main makefile...
+
+# CFLAGS+=-g -DDEBUG_EFS
+
+O_TARGET := efs.o
+O_OBJS   := dir.o file.o inode.o namei.o \
+		symlink.o
+M_OBJS   := $(O_TARGET)
+
+include $(TOPDIR)/Rules.make
diff --git a/fs/efs/dir.c b/fs/efs/dir.c
new file mode 100644
index 000000000..fa07a298f
--- /dev/null
+++ b/fs/efs/dir.c
@@ -0,0 +1,132 @@
+/* dir.c
+   
+   directory inode operations for EFS filesystem
+   
+   (C)95,96 Christian Vogelgsang
+*/
+
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/efs_fs.h>
+#include <linux/efs_fs_i.h>
+#include <linux/stat.h>
+#include <asm/uaccess.h>
+
+static int efs_readdir(struct file *,void *,filldir_t);
+extern int efs_lookup(struct inode *, struct dentry *);
+
+static struct file_operations efs_dir_ops = {
+  NULL, 
+  NULL, 
+  NULL,
+  efs_readdir,
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL
+};
+
+struct inode_operations efs_dir_in_ops = {
+  &efs_dir_ops,
+  NULL,
+  efs_lookup,
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL, 
+  NULL,
+  efs_bmap,
+  NULL,
+  NULL
+};
+
+
+/* ----- efs_readdir -----
+   readdir inode operation:
+   read the next directory entry of a given dir file
+   
+   inode     - pointer to inode struct of directory
+   filp      - pointer to file struct of directory inode
+   dirent    - pointer to dirent struct that has to be filled
+   filldir   - function to store values in the directory
+
+   return    - 0 ok, <0 error
+*/
+static int efs_readdir(struct file *filp,
+		void *dirent, filldir_t filldir)
+{
+  struct inode *inode = filp->f_dentry->d_inode;
+  struct efs_inode_info *ini = (struct efs_inode_info *)&inode->u.efs_i;
+  struct buffer_head *bh;
+  __u8  *rawdirblk;
+  __u32  iteminode;
+  __u16 namelen;
+  __u8  *nameptr;
+  __u32  numitems;
+  __u16 itemnum;
+  __u32  block;
+  __u16 rawdepos;  
+
+  /* some checks */
+  if(!inode || !inode->i_sb || !S_ISDIR(inode->i_mode)) 
+    return -EBADF;
+  
+  /* Warnings */
+  if(ini->tot!=1)
+    printk("efs_readdir: More than one extent!\n");
+  if(inode->i_size & (EFS_BLOCK_SIZE-1))
+    printk("efs_readdir: dirsize != blocksize*n\n");
+
+  /* f_pos contains: dirblock<<BLOCK_SIZE | # of item in dirblock */
+  block   = filp->f_pos >> EFS_BLOCK_SIZE_BITS;
+  itemnum = filp->f_pos & 0xff; 
+  
+  /* We found the last entry -> ready */
+  if(block == (inode->i_size>>EFS_BLOCK_SIZE_BITS))
+    return 0;
+
+  /* get disc block number from dir block num: 0..i_size/BLOCK_SIZE */ 
+  bh = bread(inode->i_dev,efs_bmap(inode,block),EFS_BLOCK_SIZE);
+  if(!bh) return 0;
+
+  /* dirblock */
+  rawdirblk = (__u8 *)bh->b_data; 
+  /* number of entries stored in this dirblock */
+  numitems = rawdirblk[EFS_DB_ENTRIES]; 
+  /* offset in block of #off diritem */
+  rawdepos = (__u16)rawdirblk[EFS_DB_FIRST+itemnum]<<1;
+
+  /* diritem first contains the inode number, the namelen and the name */
+  iteminode = ConvertLong(rawdirblk,rawdepos);
+  namelen = (__u16)rawdirblk[rawdepos+EFS_DI_NAMELEN];
+  nameptr = rawdirblk + rawdepos + EFS_DI_NAME;  
+
+#ifdef DEBUG
+  printk("efs: dir #%d @ %0#3x - inode %lx %s namelen %u\n",itemnum,rawdepos,iteminode,nameptr,namelen);
+#endif
+
+  /* copy filename and data in direntry */
+  filldir(dirent,nameptr,namelen,filp->f_pos,iteminode);
+
+  brelse(bh);
+
+  /* store pos of next item */
+  itemnum++;
+  if(itemnum==numitems) {
+    itemnum = 0;
+    block++;
+  }
+  filp->f_pos = (block<<EFS_BLOCK_SIZE_BITS) | itemnum;
+  UPDATE_ATIME(inode);
+  
+  return 0;
+}
+
diff --git a/fs/efs/file.c b/fs/efs/file.c
new file mode 100644
index 000000000..4c04616bb
--- /dev/null
+++ b/fs/efs/file.c
@@ -0,0 +1,218 @@
+/* file.c
+   
+   read files on EFS filesystems
+   now replaced by generic functions of the kernel:
+   leaves only mapping of file block number -> disk block number in this file
+   
+   (C)95,96 Christian Vogelgsang
+*/
+
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/efs_fs.h>
+#include <linux/efs_fs_i.h>
+#include <linux/efs_fs_sb.h>
+#include <linux/stat.h>
+#include <asm/uaccess.h>
+
+static struct file_operations efs_file_ops = {
+  NULL,
+  generic_file_read,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  generic_file_mmap,
+  NULL,
+  NULL,
+  NULL
+};
+
+struct inode_operations efs_file_in_ops = {
+  &efs_file_ops,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  generic_readpage,
+  NULL,
+  efs_bmap,
+  NULL,
+  NULL
+};
+ 
+#define MIN(a,b) ((a)<(b)?(a):(b))
+
+#define CHECK(num) \
+  eblk = ini->extents[num].ex_bytes[0]; \
+  epos = ini->extents[num].ex_bytes[1] & 0xffffff; \
+  elen = ini->extents[num].ex_bytes[1] >> 24; \
+  if((blk >= epos)&&(blk < (epos+elen))) \
+    result = (blk - epos) + eblk + sbi->fs_start;
+
+
+/* ----- efs_getblknum -----
+   find the disc block number for a given logical file block number
+   
+   in       - inode of file
+   blk      - logical file block number
+   
+   return   - 0 on error, or unmapped block number
+*/
+static __u32 efs_getblk(struct inode *in,__u32 blk)
+{
+  struct efs_sb_info *sbi = &in->i_sb->u.efs_sb;
+  struct efs_inode_info *ini = &in->u.efs_i;
+  struct buffer_head *bh;
+
+  __u32 result = 0;
+  __u32 eblk,epos,elen;
+  int num,extnum,readahead;
+  __u32 extblk;
+  __u16 extoff,pos,cur,tot;
+  union efs_extent *ptr;
+
+
+  /* first check the current extend */
+  cur = ini->cur;
+  tot = ini->tot;
+  CHECK(cur)
+  if(result) 
+    return result;
+    
+  /* if only one extent exists and we are here the test failed */
+  if(tot==1) {
+    printk("efs: bmap failed on one extent!\n");
+    return 0;
+  }
+
+  /* check the stored extents in the inode */
+  num = MIN(tot,EFS_MAX_EXTENTS);
+  for(pos=0;pos<num;pos++) {
+    /* don't check the current again! */
+    if(pos==cur) 
+      continue;
+
+    CHECK(pos)
+    if(result) {
+      ini->cur = pos;
+      return result;
+    }
+  }
+
+  /* If the inode has only direct extents, 
+     the above tests must have found the block's extend! */
+  if(tot<=EFS_MAX_EXTENTS) {
+    printk("efs: bmap failed for direct extents!\n");
+    return 0;
+  }  
+
+  /* --- search in the indirect extensions list blocks --- */
+#ifdef DEBUG
+  printk("efs - indirect search for %lu\n",blk);
+#endif
+
+  /* calculate block and offset for begin of extent descr and read it */
+  extblk = ini->extblk;
+  extoff = 0;
+  bh = bread(in->i_dev,extblk,EFS_BLOCK_SIZE);
+  if(!bh) {
+    printk("efs: read error in indirect extents\n");
+    return 0;
+  }
+  ptr = (union efs_extent *)bh->b_data;
+
+  pos = 0; /* number of extend store in the inode */
+  extnum = 0; /* count the extents in the indirect blocks */ 
+  readahead = 10; /* number of extents to read ahead */
+  while(1) {
+
+    /* skip last current extent store in the inode */
+    if(pos==cur) pos++;
+
+    /* read new extent in inode buffer */
+    ini->extents[pos].ex_bytes[0] = efs_swab32(ptr[pos].ex_bytes[0]);
+    ini->extents[pos].ex_bytes[1] = efs_swab32(ptr[pos].ex_bytes[1]);
+
+    /* we must still search */ 
+    if(!result) {
+      CHECK(pos)
+      if(result)
+	ini->cur = pos;
+    }
+    /* we found it already and read ahead */
+    else {
+      readahead--;
+      if(!readahead)
+	break;
+    }
+
+    /* next storage place */
+    pos++;
+    extnum++;
+
+    /* last extent checked -> finished */
+    if(extnum==tot) {
+      if(!result)
+	printk("efs: bmap on indirect failed!\n");
+      break;
+    }
+
+    extoff += 8;
+    /* need new block */
+    if(extoff==EFS_BLOCK_SIZE) {
+      extoff = 0;
+      extblk++;
+	
+      brelse(bh);
+      bh = bread(in->i_dev,extblk,EFS_BLOCK_SIZE);
+      if(!bh) {
+	printk("efs: read error in indirect extents\n");
+	return 0;
+      }
+      ptr = (union efs_extent *)bh->b_data;
+    }
+  }
+  brelse(bh);
+
+  return result;
+}  
+
+
+/* ----- efs_bmap ----- 
+   bmap: map a file block number to a device block number
+   
+   in    - inode owning the block
+   block - block number
+   
+   return - disk block
+*/
+int efs_bmap(struct inode *in, int block)
+{
+  /* quickly reject invalid block numbers */
+  if(block<0) {
+#ifdef DEBUG
+    printk("efs_bmap: block < 0\n");
+#endif
+    return 0;
+  }
+  /* since the kernel wants to read a full page of data, i.e. 8 blocks
+     we must check if the block number is not too large */
+  if(block>((in->i_size-1)>>EFS_BLOCK_SIZE_BITS)) {
+#ifdef DEBUG
+    printk("efs_bmap: block %d > max %d == %d\n",
+	   block,in->i_size>>EFS_BLOCK_SIZE_BITS,in->i_blocks);
+#endif
+    return 0;
+  }
+
+  return efs_getblk(in,block);
+}
diff --git a/fs/efs/inode.c b/fs/efs/inode.c
new file mode 100644
index 000000000..b84231cd5
--- /dev/null
+++ b/fs/efs/inode.c
@@ -0,0 +1,496 @@
+/* inode.c
+ * 
+ * Inode and Superblock handling for the EFS filesystem
+ *
+ * (C) 1995,96 Christian Vogelgsang
+ */
+ 
+#include <linux/module.h>
+#include <linux/init.h>		/* __initfunc */
+#include <linux/fs.h>
+#include <linux/efs_fs.h>
+#include <linux/efs_fs_i.h>
+#include <linux/efs_fs_sb.h>
+#include <linux/locks.h>
+
+#include <asm/uaccess.h>
+
+/* ----- Define the operations for the Superblock ----- */
+void efs_read_inode(struct inode *);
+void efs_put_super(struct super_block *);
+int efs_statfs(struct super_block *, struct statfs *,int );
+
+static struct super_operations efs_sops = {
+	efs_read_inode, 
+	NULL, /* write_inode */
+	NULL, /* put_inode */
+	NULL, /* delete_inode */
+	NULL, /* notify_change */
+	efs_put_super, 
+	NULL, /* write_super */
+	efs_statfs, 
+	NULL
+};
+
+
+/* ----- Conversion utilities ----- 
+   Get 16- and 32-bit unsigned values in big-endian format from a byte buffer
+*/
+__u32 ConvertLong(__u8 *buf, int offset)
+{
+	return *((__u32 *)(buf + offset));
+	/*  return  (__u32)buf[offset+3] |
+	    ((__u32)buf[offset+2])<<8 |
+	    ((__u32)buf[offset+1])<<16 |
+	    ((__u32)buf[offset])<<24;
+	    */
+}
+
+__u16 ConvertShort(__u8 *buf, int offset)
+{
+	return *((__u16 *)(buf + offset));
+	/*
+	  return (__u16)buf[offset+1] |
+	  ((__u16)buf[offset])<<8;
+	  */
+}
+
+
+/* ----- Install/Remove Module ----- 
+ These procedures are used to install/remove our filesystem
+ module in the linux kernel
+*/
+
+/* describe filesystem */
+struct super_block *efs_read_super(struct super_block *s, void *d, int sil);
+
+static struct file_system_type efs_fs_type = {
+	"efs",
+	FS_REQUIRES_DEV,
+	efs_read_super,
+	NULL
+};
+
+__initfunc(int init_efs_fs(void)) {
+	return register_filesystem(&efs_fs_type);
+}
+
+#ifdef MODULE
+EXPORT_NO_SYMBOLS;
+
+/* install module */
+int init_module(void)
+{
+	return init_efs_fs();
+}
+
+/* remove module */
+void cleanup_module(void)
+{
+	unregister_filesystem(&efs_fs_type);
+}
+#endif /* MODULE */
+
+#ifdef DEBUG_EFS
+void efs_dump_super(struct efs_super_block *sb) {
+	printk("efs_super_block @ 0x%p:\n", sb);
+	printk("size:     %0#8lX   firstcg:  %0#8lX\n", sb->s_size, sb->s_firstcg);
+	printk("cgfsize:  %0#8lX   cgisize:  %0#8hX\n", sb->s_cgfsize,sb->s_cgisize);
+	printk("sectors:  %0#8hX   heads:    %0#8hX\n", sb->s_sectors, sb->s_heads);
+	printk("ncg:      %0#8hX   dirty:    %0#8hX\n", sb->s_ncg, sb->s_dirty);
+	printk("time:     %0#8lX   magic:    %0#8lX\n", sb->s_time, sb->s_magic);
+	printk("fname:    %.6s   fpack:    %.6s\n", sb->s_fname, sb->s_fpack);
+	printk("bmsize:   %0#8lX   tfree:    %0#8lX\n", sb->s_bmsize, sb->s_tfree);
+	printk("tinode:   %0#8lX   bmblock:  %0#8lX\n", sb->s_tinode, sb->s_bmblock);
+	printk("replsb:   %0#8lX   lastiall: %0#8lX\n", sb->s_replsb,
+	       sb->s_lastialloc);
+	printk("checksum: %0#8lX\n", sb->s_checksum);
+} 
+
+void efs_dump_inode(struct efs_disk_inode *di) {
+	printk("efs_disk_inode @ 0x%p: ", di);
+	printk("[%o %hd %hd %u %u %u %u %u #ext=%hd %u %u]\n",
+	       di->di_mode, di->di_nlink, di->di_uid, di->di_gid, di->di_size,
+	       di->di_atime, di->di_mtime, di->di_ctime, di->di_gen, 
+	       di->di_numextents, di->di_version);
+}
+#endif
+
+/* ----- efs_checkVolDesc -----
+   Analyse the first block of a CD and check 
+   if it's a valid efs volume descriptor
+
+   blk    - buffer with the data of first block
+   silent - 0 -> verbose
+
+   return : 0 - error ; >0 - start block of filesystem
+*/
+#if 0
+static __u32 efs_checkVolDesc(__u8 *blk,int silent)
+{
+	__u32 magic;
+	__u8 *ptr;
+	__u8 name[10];
+	__u32 pos,len;
+	int i;
+
+	/* is the magic cookie here? */
+	magic = ConvertLong(blk,0);
+	if(magic!=0x0be5a941) {
+		printk("EFS: no magic on first block\n");
+		return 0;
+	}
+  
+	/* Walk through the entries of the VD */
+	/* Quite useless, but gives nice output ;-) */
+	ptr = blk + EFS_VD_ENTRYFIRST;
+	name[8] = 0;
+	while(*ptr) {
+		for(i=0;i<8;i++)
+			name[i] = ptr[i];
+
+		/* start and length of entry */
+		pos = ConvertLong(ptr,EFS_VD_ENTRYPOS);
+		len = ConvertLong(ptr,EFS_VD_ENTRYLEN);
+
+		if(!silent) 
+			printk("EFS: VolDesc: %8s blk: %08lx len: %08lx\n",
+			       name,pos,len);
+    
+		ptr+=EFS_VD_ENTRYSIZE;
+	}
+
+	pos = ConvertLong(blk,EFS_VD_FS_START);
+	printk("EFS: FS start: %08lx\n",pos);
+	return pos;
+}
+#endif
+
+/* ----- efs_checkSuper ----- 
+ Check if the given block is a valid EFS-superblock
+ 
+ sbi    - my EFS superblock info
+ block  - block that must be examined
+
+ return - 0 ok, -1 error
+*/
+static int efs_verify_super(struct efs_super_block *sb, 
+			    struct efs_sb_info *sbi, 
+			    int silent)
+{
+	__u32    magic;
+
+	magic = sb->s_magic;
+	/* check if the magic cookie is here */
+	if((magic!=EFS_MAGIC1)&&(magic!=EFS_MAGIC2)) {
+		printk("EFS: magic %#X doesn't match %#X or %#X!\n",
+		       magic, EFS_MAGIC1, EFS_MAGIC2);
+		return -1;
+	}
+
+	/* XXX should check csum */
+  
+	sbi->total_blocks = sb->s_size;
+	sbi->first_block  = sb->s_firstcg;
+	sbi->group_size   = sb->s_cgfsize;
+	sbi->inode_blocks = sb->s_cgisize;
+	sbi->total_groups = sb->s_ncg;
+    
+	return 0;    
+}
+
+
+/* ----- efs_read_super ----- 
+   read_super: if the fs gets mounted this procedure is called to
+   check if the filesystem is valid and to fill the superblock struct
+   
+   s     - superblock struct
+   d     - options for fs (unused)
+   sil   - flag to be silent
+   
+   return - filled s struct or NULL on error
+ */
+
+struct super_block *efs_read_super(struct super_block *s, void *d, int silent)
+{
+	struct buffer_head *bh;
+	struct efs_sb_info *sb_info = (struct efs_sb_info *)&s->u.efs_sb;
+	struct efs_super_block *es;
+	int error = 0;
+	int dev = s->s_dev;
+	struct inode *root_inode = NULL;
+
+	MOD_INC_USE_COUNT;
+  
+	/* say hello to my log file! */
+#ifdef EFS_DEBUG
+	if(!silent)
+		printk("EFS: --- Filesystem ---\n");
+#endif
+	/* set blocksize to 512 */
+	set_blocksize(dev, EFS_BLOCK_SIZE);
+  
+	lock_super(s);
+  
+#if 0  
+	/* Read first block of CD: the Volume Descriptor */
+	bh = bread(dev, 0, EFS_BLOCK_SIZE);
+	if(bh) {
+		sb_info->fs_start = efs_checkVolDesc((__u8 *)bh->b_data,silent);
+		if(sb_info->fs_start==0) {
+			printk("EFS: failed checking Volume Descriptor\n");
+			/* error++; */
+		}
+		brelse(bh);
+	} else {
+		printk("EFS: cannot read the first block\n");
+		error++;
+	}
+#endif 0
+
+	/* Read the Superblock */
+	if(!error) {	
+#ifdef DEBUG_EFS
+		if (!silent)
+			printk("EFS: reading superblock.\n");
+#endif
+		bh = bread(dev, EFS_BLK_SUPER,  EFS_BLOCK_SIZE );
+		if(bh) {
+			es = (struct efs_super_block *)(bh->b_data);
+#ifdef DEBUG_EFS
+			if(!silent)
+				efs_dump_super(es);
+#endif
+			if(efs_verify_super(es, sb_info, silent)) {
+				printk("EFS: failed checking Superblock\n");
+				error++;
+			}
+			brelse(bh);
+		} else {
+			printk("EFS: cannot read the superblock\n");
+			error++;
+		}
+	} 
+  
+	if(!error) {
+		s->s_blocksize = EFS_BLOCK_SIZE;
+		s->s_blocksize_bits = EFS_BLOCK_SIZE_BITS;
+    
+		s->s_magic	= EFS_SUPER_MAGIC;
+		s->s_flags	= MS_RDONLY;
+		s->s_op	= &efs_sops;
+		s->s_dev	= dev;
+		root_inode = iget(s, EFS_ROOT_INODE);
+		s->s_root = d_alloc_root(root_inode, NULL);
+		if (!s->s_root) {
+			error++;
+			printk("EFS: couldn't allocate root inode!\n");
+		}
+	}
+
+	unlock_super(s);
+  
+	if(check_disk_change(s->s_dev)) {
+		printk("EFS: Device changed!\n");
+		error++;
+	}
+
+	/* We found errors -> say goodbye! */
+	if(error) {
+		s->s_dev = 0;
+		d_delete(s->s_root);	/* XXX is this enough? */
+		printk("EFS: init failed with %d errors\n", error);
+		brelse(bh);
+		MOD_DEC_USE_COUNT;
+		return NULL;
+	} 
+
+	return s;
+}
+
+
+/* ----- efs_put_super ----- 
+   put_super: remove the filesystem and the module use count
+
+   s - superblock
+*/
+void efs_put_super(struct super_block *s)
+{
+	lock_super(s);
+	s->s_dev = 0;
+	unlock_super(s);
+	MOD_DEC_USE_COUNT;
+}
+
+
+/* ----- efs_statfs ----- 
+   statfs: get informatio on the filesystem
+   
+   s   - superblock of fs
+   buf - statfs struct that has to be filled
+*/
+int efs_statfs(struct super_block *s, struct statfs *buf,int bufsize)
+{
+	struct efs_sb_info *sbi = (struct efs_sb_info *)&s->u.generic_sbp;
+	struct statfs tmp;
+
+	tmp.f_type = EFS_SUPER_MAGIC;
+	tmp.f_bsize = EFS_BLOCK_SIZE;
+	tmp.f_blocks = sbi->total_blocks;
+	tmp.f_bfree = 0;
+	tmp.f_bavail = 0;
+	tmp.f_files = 100; /* don't know how to calculate the correct value */
+	tmp.f_ffree = 0;
+	tmp.f_namelen = NAME_MAX;
+
+	return copy_to_user(buf,&tmp,bufsize) ? -EFAULT : 0;
+}
+
+
+/* ----- efs_read_inode ----- 
+   read an inode specified by in->i_ino from disk, fill the inode
+   structure and install the correct handler for the file type
+   
+   in   - inode struct
+*/
+void efs_read_inode(struct inode *in)
+{
+	struct buffer_head *bh;
+	struct efs_sb_info *sbi = (struct efs_sb_info *)&in->i_sb->u.generic_sbp;
+	__u32 blk,off;
+	int error = 0;
+  
+	/* Calc the discblock and the offset for inode (4 Nodes fit in one block) */
+	blk = in->i_ino >> 2; 
+	blk = sbi->fs_start + sbi->first_block + 
+		(sbi->group_size * (blk / sbi->inode_blocks)) +
+		(blk % sbi->inode_blocks);
+	off = (in->i_ino&3)<<7;
+  
+	/* Read the block with the inode from disk */
+#ifdef DEBUG_EFS
+	printk("EFS: looking for inode %#xl\n", in->i_ino);
+#endif
+	bh = bread(in->i_dev,blk,EFS_BLOCK_SIZE);
+	if(bh) {
+    
+		struct efs_disk_inode *di = (struct efs_disk_inode *)(bh->b_data + off);
+		__u16 numext;
+		struct efs_inode_info *ini = &in->u.efs_i;
+		__u32 rdev;
+		int i;
+    
+		/* fill in standard inode infos */
+		in->i_mtime = efs_swab32(di->di_mtime);
+		in->i_ctime = efs_swab32(di->di_ctime);
+		in->i_atime = efs_swab32(di->di_atime);
+		in->i_size  = efs_swab32(di->di_size);
+		in->i_nlink = efs_swab16(di->di_nlink);
+		in->i_uid   = efs_swab16(di->di_uid);
+		in->i_gid   = efs_swab16(di->di_gid);
+		in->i_mode  = efs_swab16(di->di_mode);
+
+		/* Special files store their rdev value where the extends of
+		   a regular file are found */
+		/*    rdev = ConvertLong(rawnode,EFS_IN_EXTENTS);*/
+		/* XXX this isn't right */
+		rdev = efs_swab32(*(__u32 *)&di->di_u.di_dev); 
+    
+		/* -----------------------------------------------------------------
+		   The following values are stored in my private part of the Inode.
+		   They are necessary for further operations with the file */
+
+		/* get the number of extends the inode posseses */
+		numext = efs_swab16(di->di_numextents);
+
+		/* if this inode has more than EFS_MAX_EXTENDS then the extends are
+		   stored not directly in the inode but indirect on an extra block.
+		   The address of the extends-block is stored in the inode */
+		if(numext>EFS_MAX_EXTENTS) { 
+			struct buffer_head *bh2;
+			printk("EFS: inode %#Xl has > EFS_MAX_EXTENTS (%ld)\n",
+			       in->i_ino, numext);
+
+			/* Store the discblock and offset of extend-list in Inode info */
+			ini->extblk = sbi->fs_start + efs_swab32((__u32)(di->di_u.di_extents));
+
+			/* read INI_MAX_EXT extents from the indirect block */
+			bh2 = bread(in->i_dev,ini->extblk,EFS_BLOCK_SIZE);
+			if(bh2) {
+				union efs_extent *ptr = (union efs_extent *)bh2->b_data;
+				for(i=0;i<EFS_MAX_EXTENTS;i++) {
+					ini->extents[i].ex_bytes[0] = efs_swab32(ptr[i].ex_bytes[0]);
+					ini->extents[i].ex_bytes[1] = efs_swab32(ptr[i].ex_bytes[1]);
+				}
+				brelse(bh2);
+			} else
+				printk("efs: failed reading indirect extends!\n");
+
+		} else {
+#ifdef DEBUG_EFS
+			printk("EFS: inode %#Xl is direct (woohoo!)\n",
+			       in->i_ino);
+#endif
+			/* The extends are found in the inode block */
+			ini->extblk = blk;
+      
+			/* copy extends directly from rawinode */
+			for(i=0;i<numext;i++) {
+				ini->extents[i].ex_bytes[0] = efs_swab32(di->di_u.di_extents[i].ex_bytes[0]);
+				ini->extents[i].ex_bytes[1] = efs_swab32(di->di_u.di_extents[i].ex_bytes[1]);
+			}
+		}
+		ini->tot = numext;
+		ini->cur = 0;
+
+		brelse(bh);
+    
+#ifdef DEBUG_EFS
+		printk("%lx inode: blk %lx numext %x\n",in->i_ino,ini->extblk,numext);
+		efs_dump_inode(di);
+#endif
+
+		/* Install the filetype Handler */
+		switch(in->i_mode & S_IFMT) {
+		case S_IFDIR: 
+			in->i_op = &efs_dir_in_ops; 
+			break;
+		case S_IFREG:
+			in->i_op = &efs_file_in_ops;
+			break;
+		case S_IFLNK:
+			in->i_op = &efs_symlink_in_ops;
+			break;
+		case S_IFCHR:
+			in->i_rdev = rdev;
+			in->i_op = &chrdev_inode_operations; 
+			break;
+		case S_IFBLK:
+			in->i_rdev = rdev;
+			in->i_op = &blkdev_inode_operations; 
+			break;
+		case S_IFIFO:
+			init_fifo(in);
+			break;    
+		default:
+			printk("EFS: Unsupported inode Mode %o\n",(unsigned int)(in->i_mode));
+			error++;
+			break;
+		}
+        
+	} else {
+		printk("EFS: Inode: failed bread!\n");
+		error++;
+	}
+  
+	/* failed inode */
+	if(error) {
+		printk("EFS: read inode failed with %d errors\n",error);
+		in->i_mtime = in->i_atime = in->i_ctime = 0;
+		in->i_size = 0;
+		in->i_nlink = 1;
+		in->i_uid = in->i_gid = 0;
+		in->i_mode = S_IFREG;
+		in->i_op = NULL;   
+	}
+}
diff --git a/fs/efs/namei.c b/fs/efs/namei.c
new file mode 100644
index 000000000..82086accd
--- /dev/null
+++ b/fs/efs/namei.c
@@ -0,0 +1,143 @@
+/* namei.c
+   
+   name lookup for EFS filesystem
+   
+   (C)95,96 Christian Vogelgsang
+*/
+
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/efs_fs.h>
+#include <linux/efs_fs_i.h>
+#include <linux/efs_fs_sb.h>
+#include <linux/stat.h>
+#include <asm/uaccess.h>
+
+/* ----- efs_find_entry -----
+   search a raw efs dir entry for the given name
+   
+   dir     - inode of directory
+   oname   - name to search for
+   onamelen- length of name
+   
+   return  - inode number of the found entry or 0 on error
+*/
+static struct buffer_head * efs_find_entry(struct inode *dir,
+					   const char *oname,
+					   int onamelen, 
+					   struct efs_dir_entry *res_dir)
+{
+	struct efs_inode_info *ini = &dir->u.efs_i;
+	struct buffer_head *bh = NULL;
+	__u32 inode;
+	__u16 i;
+	__u8 *name;
+	__u16 namelen;
+	__u32 blknum,b;
+	struct efs_dirblk *db;
+ 
+	/* Warnings */ 
+	if(ini->tot!=1)
+		printk("efs_find: More than one extent!\n");
+	if(dir->i_size & (EFS_BLOCK_SIZE-1))
+		printk("efs_find: dirsize != blocklen * n\n");
+
+	/* Search in every dirblock */
+	inode = 0;
+	blknum = dir->i_size >> EFS_BLOCK_SIZE_BITS;
+#ifdef DEBUG_EFS
+	printk("EFS: directory with inode %#xd has %d blocks\n",
+	       dir->i_ino, blknum);
+#endif
+	for(b=0;b<blknum;b++) {
+		int db_offset;
+#ifdef DEBUG_EFS
+		printk("EFS: trying block %d\n", b);
+#endif
+		/* Read a raw dirblock */
+		bh = bread(dir->i_dev,efs_bmap(dir,b),EFS_BLOCK_SIZE);
+		if(!bh) {
+			printk("EFS: efs_bmap returned NULL!\n");
+			return 0;
+		}
+    
+		db = (struct efs_dirblk *)bh->b_data;
+		if (db->db_magic != EFS_DIRBLK_MAGIC) {
+			printk("EFS: dirblk has bad magic (%#xl)!\n",
+			       db->db_magic);
+			return NULL;
+		}
+#ifdef DEBUG_EFS
+		printk("EFS: db %d has %d entries, starting at offset %#x\n",
+		       b, db->db_slots, (__u16)db->db_firstused << 1);
+#endif
+		for(i = 0 ; i < db->db_slots ; i++) {
+			struct efs_dent * de;
+			int entry_inode;
+			db_offset = ((__u16)db->db_space[i] << 1) 
+			  - EFS_DIRBLK_HEADERSIZE;
+			de = (struct efs_dent *)(&db->db_space[db_offset]);
+
+			/* inode, namelen and name of direntry */
+			entry_inode = efs_swab32(de->ud_inum.l); 
+			namelen = de->d_namelen; 
+			name = de->d_name;
+#ifdef DEBUG_EFS
+			printk("EFS: entry %d @ %#x has inode %#x, %s/%d\n",
+			       i, db_offset, entry_inode, name, namelen);
+#endif
+			/* we found the name! */
+			if((namelen==onamelen)&&
+			   (!memcmp(oname,name,onamelen))) {
+				res_dir->inode = entry_inode;
+#ifdef DEBUG_EFS
+				printk("EFS: found inode %d\n", 
+				       entry_inode); 
+#endif
+				return bh;
+			}
+		}
+#ifdef DEBUG_EFS
+		printk("EFS: efs_find_entry didn't find inode for \"%s\"!\n",
+		       oname);
+#endif
+		return NULL;
+	}
+	printk("EFS: Falling off the end of efs_find_entry!  Bogus!\n");
+	return NULL;
+	/* not reached */
+}
+
+
+/* ----- efs_lookup -----
+   lookup inode operation:
+   check if a given name is in the dir directory
+   
+   dir       - pointer to inode of directory
+   name      - name we must search for
+   len       - length of name
+   result    - pointer to inode struct if we found it or NULL on error
+   
+   return    - 0 everything is ok or <0 on error
+*/
+int efs_lookup(struct inode *dir, struct dentry *dentry)
+{
+  struct inode *inode = NULL;
+  struct buffer_head *bh;
+  struct efs_dir_entry de;
+  
+  bh = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
+  if (bh) {
+    int ino = de.inode;
+    brelse(bh);
+    inode = iget(dir->i_sb, ino);
+
+    if (!inode) 
+      return -EACCES;
+  }
+    
+  d_add(dentry, inode);
+  return 0;
+}
diff --git a/fs/efs/symlink.c b/fs/efs/symlink.c
new file mode 100644
index 000000000..6197bb6f3
--- /dev/null
+++ b/fs/efs/symlink.c
@@ -0,0 +1,136 @@
+/* symlink.c
+ *
+ * Symbolic link handling for EFS
+ *
+ * (C)1995,96 Christian Vogelgsang
+ *
+ * Based on the symlink.c from minix-fs by Linus
+ */
+
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/efs_fs.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+
+static int efs_readlink(struct inode *, char *, int);
+static struct dentry * efs_follow_link(struct inode *, struct dentry *);
+
+struct inode_operations efs_symlink_in_ops = {
+	NULL,			/* no file-operations */
+	NULL,			/* create */
+	NULL,			/* lookup */
+	NULL,			/* link */
+	NULL,			/* unlink */
+	NULL,			/* symlink */
+	NULL,			/* mkdir */
+	NULL,			/* rmdir */
+	NULL,			/* mknod */
+	NULL,			/* rename */
+	efs_readlink,		/* readlink */
+	efs_follow_link,	/* follow_link */
+	NULL,
+	NULL,
+	NULL,			/* bmap */
+	NULL,			/* truncate */
+	NULL			/* permission */
+};
+
+
+/* ----- efs_getlinktarget -----
+   read the target of the link from the data zone of the file
+*/
+static char *efs_getlinktarget(struct inode *in)
+{
+  struct buffer_head * bh;
+  char *name;
+  __u32 size = in->i_size;
+  __u32 block;
+  
+  /* link data longer than 1024 not supported */
+  if(size>2*EFS_BLOCK_SIZE) {
+    printk("efs_getlinktarget: name too long: %lu\n",in->i_size);
+    return NULL;
+  }
+  
+  /* get some memory from the kernel to store the name */
+  name = kmalloc(size+1,GFP_KERNEL);
+  if(!name) return NULL;
+  
+  /* read first 512 bytes of target */
+  block = efs_bmap(in,0);
+  bh = bread(in->i_dev,block,EFS_BLOCK_SIZE);
+  if(!bh) {
+    kfree(name);
+    return NULL;
+  }
+  memcpy(name,bh->b_data,(size>EFS_BLOCK_SIZE)?EFS_BLOCK_SIZE:size);
+  brelse(bh);
+  
+  /* if the linktarget is long, read the next block */
+  if(size>EFS_BLOCK_SIZE) {
+    bh = bread(in->i_dev,block+1,EFS_BLOCK_SIZE);
+    if(!bh) {
+      kfree(name);
+      return NULL;
+    }
+    memcpy(name+EFS_BLOCK_SIZE,bh->b_data,size-EFS_BLOCK_SIZE);
+    brelse(bh);
+  }
+  
+  /* terminate string and return it */
+  name[size]=0;
+  return name;
+}
+
+
+/* ----- efs_follow_link -----
+   get the inode of the link target
+*/
+static struct dentry * efs_follow_link(struct inode * dir, struct dentry *base)
+{
+  struct buffer_head * bh;
+  __u32 block;
+
+  block = efs_bmap(dir,0);
+  bh = bread(dir->i_dev,block,EFS_BLOCK_SIZE);
+  if (!bh) {
+    dput(base);
+    return ERR_PTR(-EIO);
+  }
+  UPDATE_ATIME(dir);
+  base = lookup_dentry(bh->b_data, base, 1);
+  brelse(bh);
+  return base;
+}
+
+/* ----- efs_readlink -----
+   read the target of a link and return the name
+*/
+static int efs_readlink(struct inode * dir, char * buffer, int buflen)
+{
+  int i;
+  char c;
+  struct buffer_head * bh;
+  __u32 block;
+
+  block = efs_bmap(dir,0);
+  if (buflen > 1023)
+    buflen = 1023;
+  bh = bread(dir->i_dev,block,EFS_BLOCK_SIZE);
+  if (!bh)
+    return 0;
+
+  /* copy the link target to the given buffer */
+  i = 0;
+  while (i<buflen && (c = bh->b_data[i])) {
+    i++;
+    put_user(c,buffer++);
+  }
+
+  brelse(bh);
+  return i;
+}
diff --git a/fs/filesystems.c b/fs/filesystems.c
index 74016aa67..348ad7bb7 100644
--- a/fs/filesystems.c
+++ b/fs/filesystems.c
@@ -24,6 +24,7 @@
 #include <linux/ufs_fs.h>
 #include <linux/romfs_fs.h>
 #include <linux/auto_fs.h>
+#include <linux/efs_fs.h>
 #include <linux/major.h>
 #include <linux/smp.h>
 #include <linux/smp_lock.h>
@@ -116,6 +117,10 @@ __initfunc(static void do_sys_setup(void))
 	init_autofs_fs();
 #endif
 
+#ifdef CONFIG_EFS_FS
+	init_efs_fs();
+#endif
+
 	mount_root();
 }