From b92327fe6b25d60004b79df9e3c19091c03118ba Mon Sep 17 00:00:00 2001
From: Steve French <sfrench@us.ibm.com>
Date: Mon, 22 Aug 2005 20:09:43 -0700
Subject: [PATCH] [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  |  1 +
 fs/cifs/dir.c     | 54 ++++++++++++++++++++++++++++++++++++++++++++---
 fs/cifs/inode.c   |  5 ++++-
 fs/cifs/link.c    |  5 ++++-
 fs/cifs/readdir.c |  5 ++++-
 5 files changed, 64 insertions(+), 6 deletions(-)

diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index d5fb3441555f..bb3404a99e5f 100644
--- a/fs/cifs/cifsfs.h
+++ b/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);
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index c619d45060ce..5311c50734b0 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -230,7 +230,10 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 			     ("Create worked but get_inode_info failed rc = %d",
 			      rc));
 		} else {
-			direntry->d_op = &cifs_dentry_ops;
+			if (pTcon->nocase)
+				direntry->d_op = &cifs_ci_dentry_ops;
+			else
+				direntry->d_op = &cifs_dentry_ops;
 			d_instantiate(direntry, newinode);
 		}
 		if((nd->flags & LOOKUP_OPEN) == FALSE) {
@@ -322,7 +325,10 @@ 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);
-			direntry->d_op = &cifs_dentry_ops;
+			if (pTcon->nocase)
+				direntry->d_op = &cifs_ci_dentry_ops;
+			else
+				direntry->d_op = &cifs_dentry_ops;
 			if(rc == 0)
 				d_instantiate(direntry, newinode);
 		}
@@ -418,7 +424,10 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct name
 					 parent_dir_inode->i_sb,xid);
 
 	if ((rc == 0) && (newInode != NULL)) {
-		direntry->d_op = &cifs_dentry_ops;
+		if (pTcon->nocase)
+			direntry->d_op = &cifs_ci_dentry_ops;
+		else
+			direntry->d_op = &cifs_dentry_ops;
 		d_add(direntry, newInode);
 
 		/* since paths are not looked up by component - the parent directories are presumed to be good here */
@@ -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,
+};
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index ed3e9207d92e..2d50b3507d13 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -591,7 +591,10 @@ int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
 			rc = cifs_get_inode_info(&newinode, full_path, NULL,
 						 inode->i_sb,xid);
 
-		direntry->d_op = &cifs_dentry_ops;
+		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)
 			direntry->d_inode->i_nlink = 2;
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index da420e8c3298..b8ec6646456a 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -199,7 +199,10 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 			     ("Create symlink worked but get_inode_info failed with rc = %d ",
 			      rc));
 		} else {
-			direntry->d_op = &cifs_dentry_ops;
+			if (pTcon->nocase)
+				direntry->d_op = &cifs_ci_dentry_ops;
+			else
+				direntry->d_op = &cifs_dentry_ops;
 			d_instantiate(direntry, newinode);
 		}
 	}
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index ef5eb804ce82..f769292e2a93 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -91,7 +91,10 @@ static int construct_dentry(struct qstr *qstring, struct file *file,
 		}
 
 		*ptmp_inode = new_inode(file->f_dentry->d_sb);
-		tmp_dentry->d_op = &cifs_dentry_ops;
+		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;
 		rc = 1;