Merge tag '4.20-rc7-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull smb3 fix from Steve French:
 "An important smb3 fix for an regression to some servers introduced by
  compounding optimization to rmdir.

  This fix has been tested by multiple developers (including me) with
  the usual private xfstesting, but also by the new cifs/smb3 "buildbot"
  xfstest VMs (thank you Ronnie and Aurelien for good work on this
  automation). The automated testing has been updated so that it will
  catch problems like this in the future.

  Note that Pavel discovered (very recently) some unrelated but
  extremely important bugs in credit handling (smb3 flow control problem
  that can lead to disconnects/reconnects) when compounding, that I
  would have liked to send in ASAP but the complete testing of those two
  fixes may not be done in time and have to wait for 4.21"

* tag '4.20-rc7-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: Fix rmdir compounding regression to strict servers

3 files changed, 25 insertions, 17 deletions

diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index 9e7ef7ec2d70f0..a8999f930b224e 100644
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -97,7 +97,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 	if (rc)
 		goto finished;
 
-	smb2_set_next_command(server, &rqst[num_rqst++]);
+	smb2_set_next_command(server, &rqst[num_rqst++], 0);
 
 	/* Operation */
 	switch (command) {
@@ -111,7 +111,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 				SMB2_O_INFO_FILE, 0,
 				sizeof(struct smb2_file_all_info) +
 					  PATH_MAX * 2, 0, NULL);
-		smb2_set_next_command(server, &rqst[num_rqst]);
+		smb2_set_next_command(server, &rqst[num_rqst], 0);
 		smb2_set_related(&rqst[num_rqst++]);
 		break;
 	case SMB2_OP_DELETE:
@@ -127,14 +127,14 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 		rqst[num_rqst].rq_iov = si_iov;
 		rqst[num_rqst].rq_nvec = 1;
 
-		size[0] = 8;
+		size[0] = 1; /* sizeof __u8 See MS-FSCC section 2.4.11 */
 		data[0] = &delete_pending[0];
 
 		rc = SMB2_set_info_init(tcon, &rqst[num_rqst], COMPOUND_FID,
 					COMPOUND_FID, current->tgid,
 					FILE_DISPOSITION_INFORMATION,
 					SMB2_O_INFO_FILE, 0, data, size);
-		smb2_set_next_command(server, &rqst[num_rqst]);
+		smb2_set_next_command(server, &rqst[num_rqst], 1);
 		smb2_set_related(&rqst[num_rqst++]);
 		break;
 	case SMB2_OP_SET_EOF:
@@ -149,7 +149,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 					COMPOUND_FID, current->tgid,
 					FILE_END_OF_FILE_INFORMATION,
 					SMB2_O_INFO_FILE, 0, data, size);
-		smb2_set_next_command(server, &rqst[num_rqst]);
+		smb2_set_next_command(server, &rqst[num_rqst], 0);
 		smb2_set_related(&rqst[num_rqst++]);
 		break;
 	case SMB2_OP_SET_INFO:
@@ -165,7 +165,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 					COMPOUND_FID, current->tgid,
 					FILE_BASIC_INFORMATION,
 					SMB2_O_INFO_FILE, 0, data, size);
-		smb2_set_next_command(server, &rqst[num_rqst]);
+		smb2_set_next_command(server, &rqst[num_rqst], 0);
 		smb2_set_related(&rqst[num_rqst++]);
 		break;
 	case SMB2_OP_RENAME:
@@ -189,7 +189,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 					COMPOUND_FID, current->tgid,
 					FILE_RENAME_INFORMATION,
 					SMB2_O_INFO_FILE, 0, data, size);
-		smb2_set_next_command(server, &rqst[num_rqst]);
+		smb2_set_next_command(server, &rqst[num_rqst], 0);
 		smb2_set_related(&rqst[num_rqst++]);
 		break;
 	case SMB2_OP_HARDLINK:
@@ -213,7 +213,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 					COMPOUND_FID, current->tgid,
 					FILE_LINK_INFORMATION,
 					SMB2_O_INFO_FILE, 0, data, size);
-		smb2_set_next_command(server, &rqst[num_rqst]);
+		smb2_set_next_command(server, &rqst[num_rqst], 0);
 		smb2_set_related(&rqst[num_rqst++]);
 		break;
 	default:
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 225fec1cfa6733..e25c7aade98a41 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1194,7 +1194,7 @@ smb2_ioctl_query_info(const unsigned int xid,
 	rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, path);
 	if (rc)
 		goto iqinf_exit;
-	smb2_set_next_command(ses->server, &rqst[0]);
+	smb2_set_next_command(ses->server, &rqst[0], 0);
 
 	/* Query */
 	memset(&qi_iov, 0, sizeof(qi_iov));
@@ -1208,7 +1208,7 @@ smb2_ioctl_query_info(const unsigned int xid,
 				  qi.output_buffer_length, buffer);
 	if (rc)
 		goto iqinf_exit;
-	smb2_set_next_command(ses->server, &rqst[1]);
+	smb2_set_next_command(ses->server, &rqst[1], 0);
 	smb2_set_related(&rqst[1]);
 
 	/* Close */
@@ -1761,16 +1761,23 @@ smb2_set_related(struct smb_rqst *rqst)
 char smb2_padding[7] = {0, 0, 0, 0, 0, 0, 0};
 
 void
-smb2_set_next_command(struct TCP_Server_Info *server, struct smb_rqst *rqst)
+smb2_set_next_command(struct TCP_Server_Info *server, struct smb_rqst *rqst,
+		      bool has_space_for_padding)
 {
 	struct smb2_sync_hdr *shdr;
 	unsigned long len = smb_rqst_len(server, rqst);
 
 	/* SMB headers in a compound are 8 byte aligned. */
 	if (len & 7) {
-		rqst->rq_iov[rqst->rq_nvec].iov_base = smb2_padding;
-		rqst->rq_iov[rqst->rq_nvec].iov_len = 8 - (len & 7);
-		rqst->rq_nvec++;
+		if (has_space_for_padding) {
+			len = rqst->rq_iov[rqst->rq_nvec - 1].iov_len;
+			rqst->rq_iov[rqst->rq_nvec - 1].iov_len =
+				(len + 7) & ~7;
+		} else {
+			rqst->rq_iov[rqst->rq_nvec].iov_base = smb2_padding;
+			rqst->rq_iov[rqst->rq_nvec].iov_len = 8 - (len & 7);
+			rqst->rq_nvec++;
+		}
 		len = smb_rqst_len(server, rqst);
 	}
 
@@ -1820,7 +1827,7 @@ smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
 	rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, &srch_path);
 	if (rc)
 		goto qfs_exit;
-	smb2_set_next_command(server, &rqst[0]);
+	smb2_set_next_command(server, &rqst[0], 0);
 
 	memset(&qi_iov, 0, sizeof(qi_iov));
 	rqst[1].rq_iov = qi_iov;
@@ -1833,7 +1840,7 @@ smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
 				  NULL);
 	if (rc)
 		goto qfs_exit;
-	smb2_set_next_command(server, &rqst[1]);
+	smb2_set_next_command(server, &rqst[1], 0);
 	smb2_set_related(&rqst[1]);
 
 	memset(&close_iov, 0, sizeof(close_iov));
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index 9f4e9ed9ce53c2..2fe78acd7d0c14 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -117,7 +117,8 @@ extern int smb3_crypto_aead_allocate(struct TCP_Server_Info *server);
 extern unsigned long smb_rqst_len(struct TCP_Server_Info *server,
 				  struct smb_rqst *rqst);
 extern void smb2_set_next_command(struct TCP_Server_Info *server,
-				  struct smb_rqst *rqst);
+				  struct smb_rqst *rqst,
+				  bool has_space_for_padding);
 extern void smb2_set_related(struct smb_rqst *rqst);
 
 /*