[PATCH 1/2] cifs: Extend ->set_EA() callback to allow operate on reparse point

["Pali Rohár" <pali@kernel.org>]

Upcoming changes for setting EAs needs to operate on the reparse point
itself. This change extend >set_EA() callback with a new boolean parameter
to allow it.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 fs/smb/client/cifsglob.h  |  1 +
 fs/smb/client/cifsproto.h |  3 ++-
 fs/smb/client/cifssmb.c   | 20 +++++++++++++++++++-
 fs/smb/client/smb2ops.c   |  6 ++++--
 fs/smb/client/xattr.c     |  3 ++-
 5 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index fffb1b2dc09f..6a84d5eae578 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -571,6 +571,7 @@ struct smb_version_operations {
 			const unsigned char *, const unsigned char *, char *,
 			size_t, struct cifs_sb_info *);
 	int (*set_EA)(const unsigned int, struct cifs_tcon *, const char *,
+			bool open_reparse_point,
 			const char *, const void *, const __u16,
 			const struct nls_table *, struct cifs_sb_info *);
 	struct smb_ntsd * (*get_acl)(struct cifs_sb_info *cifssb, struct inode *ino,
diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index 4fbd42b98703..e449b33d9bdc 100644
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -567,7 +567,8 @@ extern ssize_t CIFSSMBQAllEAs(const unsigned int xid, struct cifs_tcon *tcon,
 			const unsigned char *ea_name, char *EAData,
 			size_t bufsize, struct cifs_sb_info *cifs_sb);
 extern int CIFSSMBSetEA(const unsigned int xid, struct cifs_tcon *tcon,
-		const char *fileName, const char *ea_name,
+		const char *fileName, bool open_reparse_point,
+		const char *ea_name,
 		const void *ea_value, const __u16 ea_value_len,
 		const struct nls_table *nls_codepage,
 		struct cifs_sb_info *cifs_sb);
diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c
index 54183d7dcc85..44b3f7be0f58 100644
--- a/fs/smb/client/cifssmb.c
+++ b/fs/smb/client/cifssmb.c
@@ -2885,6 +2885,7 @@ struct inode *cifs_create_reparse_inode(struct cifs_open_info_data *data,
 			rc = CIFSSMBSetEA(xid,
 					  tcon,
 					  full_path,
+					  true /* open reparse point */,
 					  &ea->ea_data[0],
 					  &ea->ea_data[ea->ea_name_length+1],
 					  le16_to_cpu(ea->ea_value_length),
@@ -5961,7 +5962,8 @@ CIFSSMBQAllEAs(const unsigned int xid, struct cifs_tcon *tcon,
 
 int
 CIFSSMBSetEA(const unsigned int xid, struct cifs_tcon *tcon,
-	     const char *fileName, const char *ea_name, const void *ea_value,
+	     const char *fileName, bool open_reparse_point,
+	     const char *ea_name, const void *ea_value,
 	     const __u16 ea_value_len, const struct nls_table *nls_codepage,
 	     struct cifs_sb_info *cifs_sb)
 {
@@ -5974,6 +5976,22 @@ CIFSSMBSetEA(const unsigned int xid, struct cifs_tcon *tcon,
 	__u16 params, param_offset, byte_count, offset, count;
 	int remap = cifs_remap(cifs_sb);
 
+	/*
+	 * On NT systems which supports reparse points, the TRANS2_SET_PATH_INFORMATION
+	 * operates on the reparse point itself and not the path location where reparse
+	 * point redirects. So the behavior of TRANS2_SET_PATH_INFORMATION is as if the
+	 * path was opened with OPEN_REPARSE_POINT flag. Hence this SMB1 SetEA function
+	 * implements only the behavior of "open_reparse_point=true" parameter.
+	 *
+	 * TODO: Implement "open_reparse_point=false" support for SMB1 SetEA. For this
+	 * is needed to call NT OPEN without OPEN_REPARSE_POINT flag and then call
+	 * TRANS2_SET_FILE_INFORMATION.
+	 *
+	 * On systems which do not support reparse points, the behavior of of both
+	 * "open_reparse_point=true" and "open_reparse_point=false" is same.
+	 */
+	(void)open_reparse_point;
+
 	cifs_dbg(FYI, "In SetEA\n");
 SetEARetry:
 	rc = smb_init(SMB_COM_TRANSACTION2, 15, tcon, (void **) &pSMB,
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index b2aa802c7521..7ce8472a90dd 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -1155,7 +1155,8 @@ smb2_query_eas(const unsigned int xid, struct cifs_tcon *tcon,
 
 static int
 smb2_set_ea(const unsigned int xid, struct cifs_tcon *tcon,
-	    const char *path, const char *ea_name, const void *ea_value,
+	    const char *path, bool open_reparse_point,
+	    const char *ea_name, const void *ea_value,
 	    const __u16 ea_value_len, const struct nls_table *nls_codepage,
 	    struct cifs_sb_info *cifs_sb)
 {
@@ -1256,7 +1257,8 @@ smb2_set_ea(const unsigned int xid, struct cifs_tcon *tcon,
 		.path = path,
 		.desired_access = FILE_WRITE_EA,
 		.disposition = FILE_OPEN,
-		.create_options = cifs_create_options(cifs_sb, 0),
+		.create_options = cifs_create_options(cifs_sb,
+				open_reparse_point ? OPEN_REPARSE_POINT : 0),
 		.fid = &fid,
 		.replay = !!(retries),
 	};
diff --git a/fs/smb/client/xattr.c b/fs/smb/client/xattr.c
index b88fa04f5792..26193249dbd8 100644
--- a/fs/smb/client/xattr.c
+++ b/fs/smb/client/xattr.c
@@ -155,7 +155,8 @@ static int cifs_xattr_set(const struct xattr_handler *handler,
 
 		if (pTcon->ses->server->ops->set_EA) {
 			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
-				full_path, name, value, (__u16)size,
+				full_path, false /* open reparse point */,
+				name, value, (__u16)size,
 				cifs_sb->local_nls, cifs_sb);
 			if (rc == 0)
 				inode_set_ctime_current(inode);
-- 
2.20.1