Remap reserved posix characters by default (part 3/3)

This is a bigger patch, but its size is mostly due to
a single change for how we check for remapping illegal characters
in file names - a lot of repeated, small changes to
the way callers request converting file names.

The final patch in the series does the following:

1) changes default behavior for cifs to be more intuitive.
Currently we do not map by default to seven reserved characters,
ie those valid in POSIX but not in NTFS/CIFS/SMB3/Windows,
unless a mount option (mapchars) is specified.  Change this
to by default always map and map using the SFM maping
(like the Mac uses) unless the server negotiates the CIFS Unix
Extensions (like Samba does when mounting with the cifs protocol)
when the remapping of the characters is unnecessary.  This should
help SMB3 mounts in particular since Samba will likely be
able to implement this mapping with its new "vfs_fruit" module
as it will be doing for the Mac.
2) if the user specifies the existing "mapchars" mount option then
use the "SFU" (Microsoft Services for Unix, SUA) style mapping of
the seven characters instead.
3) if the user specifies "nomapposix" then disable SFM/MAC style mapping
(so no character remapping would be used unless the user specifies
"mapchars" on mount as well, as above).
4) change all the places in the code that check for the superblock
flag on the mount which is set by mapchars and passed in on all
path based operation and change it to use a small function call
instead to set the mapping type properly (and check for the
mapping type in the cifs unicode functions)

Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 12 insertions, 20 deletions

diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
index 5ac836a..72a4d10 100644
--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -28,6 +28,8 @@
 #include "cifsglob.h"
 #include "cifsproto.h"
 #include "cifs_debug.h"
+#include "cifs_fs_sb.h"
+#include "cifs_unicode.h"
 
 #define MAX_EA_VALUE_SIZE 65535
 #define CIFS_XATTR_DOS_ATTRIB "user.DosAttrib"
@@ -85,8 +87,7 @@ int cifs_removexattr(struct dentry *direntry, const char *ea_name)
 		if (pTcon->ses->server->ops->set_EA)
 			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
 				full_path, ea_name, NULL, (__u16)0,
-				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				cifs_sb->local_nls, cifs_remap(cifs_sb));
 	}
 remove_ea_exit:
 	kfree(full_path);
@@ -154,8 +155,7 @@ int cifs_setxattr(struct dentry *direntry, const char *ea_name,
 		if (pTcon->ses->server->ops->set_EA)
 			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
 				full_path, ea_name, ea_value, (__u16)value_size,
-				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				cifs_sb->local_nls, cifs_remap(cifs_sb));
 	} else if (strncmp(ea_name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)
 		   == 0) {
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
@@ -165,8 +165,7 @@ int cifs_setxattr(struct dentry *direntry, const char *ea_name,
 		if (pTcon->ses->server->ops->set_EA)
 			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
 				full_path, ea_name, ea_value, (__u16)value_size,
-				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				cifs_sb->local_nls, cifs_remap(cifs_sb));
 	} else if (strncmp(ea_name, CIFS_XATTR_CIFS_ACL,
 			strlen(CIFS_XATTR_CIFS_ACL)) == 0) {
 #ifdef CONFIG_CIFS_ACL
@@ -199,8 +198,7 @@ int cifs_setxattr(struct dentry *direntry, const char *ea_name,
 				rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 					ea_value, (const int)value_size,
 					ACL_TYPE_ACCESS, cifs_sb->local_nls,
-					cifs_sb->mnt_cifs_flags &
-						CIFS_MOUNT_MAP_SPECIAL_CHR);
+					cifs_remap(cifs_sb));
 			cifs_dbg(FYI, "set POSIX ACL rc %d\n", rc);
 #else
 			cifs_dbg(FYI, "set POSIX ACL not supported\n");
@@ -212,8 +210,7 @@ int cifs_setxattr(struct dentry *direntry, const char *ea_name,
 				rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 					ea_value, (const int)value_size,
 					ACL_TYPE_DEFAULT, cifs_sb->local_nls,
-					cifs_sb->mnt_cifs_flags &
-						CIFS_MOUNT_MAP_SPECIAL_CHR);
+					cifs_remap(cifs_sb));
 			cifs_dbg(FYI, "set POSIX default ACL rc %d\n", rc);
 #else
 			cifs_dbg(FYI, "set default POSIX ACL not supported\n");
@@ -285,8 +282,7 @@ ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
 		if (pTcon->ses->server->ops->query_all_EAs)
 			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 				full_path, ea_name, ea_value, buf_size,
-				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				cifs_sb->local_nls, cifs_remap(cifs_sb));
 	} else if (strncmp(ea_name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 			goto get_ea_exit;
@@ -295,8 +291,7 @@ ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
 		if (pTcon->ses->server->ops->query_all_EAs)
 			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 				full_path, ea_name, ea_value, buf_size,
-				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				cifs_sb->local_nls, cifs_remap(cifs_sb));
 	} else if (strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,
 			  strlen(POSIX_ACL_XATTR_ACCESS)) == 0) {
 #ifdef CONFIG_CIFS_POSIX
@@ -304,8 +299,7 @@ ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
 			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 				ea_value, buf_size, ACL_TYPE_ACCESS,
 				cifs_sb->local_nls,
-				cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				cifs_remap(cifs_sb));
 #else
 		cifs_dbg(FYI, "Query POSIX ACL not supported yet\n");
 #endif /* CONFIG_CIFS_POSIX */
@@ -316,8 +310,7 @@ ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
 			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 				ea_value, buf_size, ACL_TYPE_DEFAULT,
 				cifs_sb->local_nls,
-				cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				cifs_remap(cifs_sb));
 #else
 		cifs_dbg(FYI, "Query POSIX default ACL not supported yet\n");
 #endif /* CONFIG_CIFS_POSIX */
@@ -421,8 +414,7 @@ ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
 	if (pTcon->ses->server->ops->query_all_EAs)
 		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 				full_path, NULL, data, buf_size,
-				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				cifs_sb->local_nls, cifs_remap(cifs_sb));
 list_ea_exit:
 	kfree(full_path);
 	free_xid(xid);