sysv: bury the broken "quietly truncate the long filenames" logics

It's contrary to the normal semantics, only sysv and adfs try to
do that (on any other filesystem you'll get -ENAMETOOLONG instead
of quiet truncation) and nobody actually uses that - it got
accidentally broken 5 years ago and nobody noticed.  Time to
bury it...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/sysv/namei.c

@@ -28,21 +28,6 @@ static int add_nondir(struct dentry *dentry, struct inode *inode)
 	return err;
 }
 
-static int sysv_hash(const struct dentry *dentry, struct qstr *qstr)
-{
-	/* Truncate the name in place, avoids having to define a compare
-	   function. */
-	if (qstr->len > SYSV_NAMELEN) {
-		qstr->len = SYSV_NAMELEN;
-		qstr->hash = full_name_hash(dentry, qstr->name, qstr->len);
-	}
-	return 0;
-}
-
-const struct dentry_operations sysv_dentry_operations = {
-	.d_hash		= sysv_hash,
-};
-
 static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
 {
 	struct inode * inode = NULL;

fs/sysv/super.c

@@ -312,7 +312,6 @@ static int complete_read_super(struct super_block *sb, int silent, int size)
 
 	flavour_setup[sbi->s_type](sbi, &sb->s_max_links);
 	
-	sbi->s_truncate = 1;
 	sbi->s_ndatazones = sbi->s_nzones - sbi->s_firstdatazone;
 	sbi->s_inodes_per_block = bsize >> 6;
 	sbi->s_inodes_per_block_1 = (bsize >> 6)-1;
@@ -334,8 +333,6 @@ static int complete_read_super(struct super_block *sb, int silent, int size)
 	sb->s_op = &sysv_sops;
 	if (sbi->s_forced_ro)
 		sb->s_flags |= SB_RDONLY;
-	if (sbi->s_truncate)
-		sb->s_d_op = &sysv_dentry_operations;
 	root_inode = sysv_iget(sb, SYSV_ROOT_INO);
 	if (IS_ERR(root_inode)) {
 		printk("SysV FS: get root inode failed\n");

fs/sysv/sysv.h

@@ -23,8 +23,6 @@ struct sysv_sb_info {
 	struct super_block *s_sb;	/* VFS superblock */
 	int	       s_type;		/* file system type: FSTYPE_{XENIX|SYSV|COH} */
 	char	       s_bytesex;	/* bytesex (le/be/pdp) */
-	char	       s_truncate;	/* if 1: names > SYSV_NAMELEN chars are truncated */
-					/* if 0: they are disallowed (ENAMETOOLONG) */
 	unsigned int   s_inodes_per_block;	/* number of inodes per block */
 	unsigned int   s_inodes_per_block_1;	/* inodes_per_block - 1 */
 	unsigned int   s_inodes_per_block_bits;	/* log2(inodes_per_block) */
@@ -166,7 +164,6 @@ extern const struct file_operations sysv_file_operations;
 extern const struct file_operations sysv_dir_operations;
 extern const struct address_space_operations sysv_aops;
 extern const struct super_operations sysv_sops;
-extern const struct dentry_operations sysv_dentry_operations;
 
 
 enum {