[CIFS] Finish up of case-insensitive dentry handling for cifs. This

will eventually (or should eventually) be common code for jfs, smbfs,
etc. but in the meantime is small enough and necessary when mounting
case insensitive to Windows (nocase).

Signed-off-by: Shaggy (shaggy@austin.ibm.com)
Signed-off-by: Steve French (sfrench@us.ibm.com)

fs/cifs/cifsfs.h

@@ -81,6 +81,7 @@ extern int cifs_dir_notify(struct file *, unsigned long arg);
 
 /* Functions related to dir entries */
 extern struct dentry_operations cifs_dentry_ops;
+extern struct dentry_operations cifs_ci_dentry_ops;
 
 /* Functions related to symlinks */
 extern void *cifs_follow_link(struct dentry *direntry, struct nameidata *nd);

fs/cifs/dir.c

@@ -230,6 +230,9 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 			     ("Create worked but get_inode_info failed rc = %d",
 			      rc));
 		} else {
+			if (pTcon->nocase)
+				direntry->d_op = &cifs_ci_dentry_ops;
+			else
 				direntry->d_op = &cifs_dentry_ops;
 			d_instantiate(direntry, newinode);
 		}
@@ -322,6 +325,9 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t dev
 		if(!rc) {
 			rc = cifs_get_inode_info_unix(&newinode, full_path,
 						inode->i_sb,xid);
+			if (pTcon->nocase)
+				direntry->d_op = &cifs_ci_dentry_ops;
+			else
 				direntry->d_op = &cifs_dentry_ops;
 			if(rc == 0)
 				d_instantiate(direntry, newinode);
@@ -418,6 +424,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct name
 					 parent_dir_inode->i_sb,xid);
 
 	if ((rc == 0) && (newInode != NULL)) {
+		if (pTcon->nocase)
+			direntry->d_op = &cifs_ci_dentry_ops;
+		else
 			direntry->d_op = &cifs_dentry_ops;
 		d_add(direntry, newInode);
 
@@ -477,3 +486,42 @@ struct dentry_operations cifs_dentry_ops = {
 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 	/* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 };
+
+static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
+{
+	struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
+	unsigned long hash;
+	int i;
+
+	hash = init_name_hash();
+	for (i = 0; i < q->len; i++)
+		hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
+					 hash);
+	q->hash = end_name_hash(hash);
+
+	return 0;
+}
+
+static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
+			   struct qstr *b)
+{
+	struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
+
+	if ((a->len == b->len) &&
+	    (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
+		/*
+		 * To preserve case, don't let an existing negative dentry's
+		 * case take precedence.  If a is not a negative dentry, this
+		 * should have no side effects
+		 */
+		memcpy((unsigned char *)a->name, b->name, a->len);
+		return 0;
+	}
+	return 1;
+}
+
+struct dentry_operations cifs_ci_dentry_ops = {
+	.d_revalidate = cifs_d_revalidate,
+	.d_hash = cifs_ci_hash,
+	.d_compare = cifs_ci_compare,
+};

fs/cifs/inode.c

@@ -591,6 +591,9 @@ int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
 			rc = cifs_get_inode_info(&newinode, full_path, NULL,
 						 inode->i_sb,xid);
 
+		if (pTcon->nocase)
+			direntry->d_op = &cifs_ci_dentry_ops;
+		else
 			direntry->d_op = &cifs_dentry_ops;
 		d_instantiate(direntry, newinode);
 		if (direntry->d_inode)

fs/cifs/link.c

@@ -199,6 +199,9 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 			     ("Create symlink worked but get_inode_info failed with rc = %d ",
 			      rc));
 		} else {
+			if (pTcon->nocase)
+				direntry->d_op = &cifs_ci_dentry_ops;
+			else
 				direntry->d_op = &cifs_dentry_ops;
 			d_instantiate(direntry, newinode);
 		}

fs/cifs/readdir.c

@@ -91,6 +91,9 @@ static int construct_dentry(struct qstr *qstring, struct file *file,
 		}
 
 		*ptmp_inode = new_inode(file->f_dentry->d_sb);
+		if (pTcon->nocase)
+			tmp_dentry->d_op = &cifs_ci_dentry_ops;
+		else
 			tmp_dentry->d_op = &cifs_dentry_ops;
 		if(*ptmp_inode == NULL)
 			return rc;