cifs: Switch to generic xattr handlers

Use xattr handlers for resolving attribute names.  The amount of setup
code required on cifs is nontrivial, so use the same get and set
functions for all handlers, with switch statements for the different
types of attributes in them.

The set_EA handler can handle NULL values, so we don't need a separate
removexattr function anymore.  Remove the cifs_dbg statements related to
xattr name resolution; they don't add much.  Don't build xattr.o when
CONFIG_CIFS_XATTR is not defined.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 1d86fc6..43cc522b 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -37,6 +37,7 @@
 #include <linux/freezer.h>
 #include <linux/namei.h>
 #include <linux/random.h>
+#include <linux/xattr.h>
 #include <net/ipv6.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
@@ -135,6 +136,7 @@
 
 	sb->s_magic = CIFS_MAGIC_NUMBER;
 	sb->s_op = &cifs_super_ops;
+	sb->s_xattr = cifs_xattr_handlers;
 	sb->s_bdi = &cifs_sb->bdi;
 	sb->s_blocksize = CIFS_MAX_MSGSIZE;
 	sb->s_blocksize_bits = 14;	/* default 2**14 = CIFS_MAX_MSGSIZE */
@@ -892,12 +894,10 @@
 	.setattr = cifs_setattr,
 	.symlink = cifs_symlink,
 	.mknod   = cifs_mknod,
-#ifdef CONFIG_CIFS_XATTR
-	.setxattr = cifs_setxattr,
-	.getxattr = cifs_getxattr,
+	.setxattr = generic_setxattr,
+	.getxattr = generic_getxattr,
 	.listxattr = cifs_listxattr,
-	.removexattr = cifs_removexattr,
-#endif
+	.removexattr = generic_removexattr,
 };
 
 const struct inode_operations cifs_file_inode_ops = {
@@ -905,12 +905,10 @@
 	.setattr = cifs_setattr,
 	.getattr = cifs_getattr, /* do we need this anymore? */
 	.permission = cifs_permission,
-#ifdef CONFIG_CIFS_XATTR
-	.setxattr = cifs_setxattr,
-	.getxattr = cifs_getxattr,
+	.setxattr = generic_setxattr,
+	.getxattr = generic_getxattr,
 	.listxattr = cifs_listxattr,
-	.removexattr = cifs_removexattr,
-#endif
+	.removexattr = generic_removexattr,
 };
 
 const struct inode_operations cifs_symlink_inode_ops = {
@@ -920,12 +918,10 @@
 	/* BB add the following two eventually */
 	/* revalidate: cifs_revalidate,
 	   setattr:    cifs_notify_change, *//* BB do we need notify change */
-#ifdef CONFIG_CIFS_XATTR
-	.setxattr = cifs_setxattr,
-	.getxattr = cifs_getxattr,
+	.setxattr = generic_setxattr,
+	.getxattr = generic_getxattr,
 	.listxattr = cifs_listxattr,
-	.removexattr = cifs_removexattr,
-#endif
+	.removexattr = generic_removexattr,
 };
 
 static int cifs_clone_file_range(struct file *src_file, loff_t off,