Merge tag '5.7-rc-smb3-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs updates from Steve French:
 "First part of cifs/smb3 changes for merge window (others are still
  being tested). Various RDMA (smbdirect) fixes, addition of SMB3.1.1
  POSIX support in readdir, 3 fixes for stable, and a fix for flock.

  Summary:

  New feature:
   - SMB3.1.1 POSIX support in readdir

  Fixes:
   - various RDMA (smbdirect) fixes
   - fix for flock
   - fallocate fix
   - some improved mount warnings
   - two timestamp related fixes
   - reconnect fix
   - three fixes for stable"

* tag '5.7-rc-smb3-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6: (28 commits)
  cifs: update internal module version number
  cifs: Allocate encryption header through kmalloc
  cifs: smbd: Check and extend sender credits in interrupt context
  cifs: smbd: Calculate the correct maximum packet size for segmented SMBDirect send/receive
  smb3: use SMB2_SIGNATURE_SIZE define
  CIFS: Fix bug which the return value by asynchronous read is error
  CIFS: check new file size when extending file by fallocate
  SMB3: Minor cleanup of protocol definitions
  SMB3: Additional compression structures
  SMB3: Add new compression flags
  cifs: smb2pdu.h: Replace zero-length array with flexible-array member
  cifs: clear PF_MEMALLOC before exiting demultiplex thread
  cifs: cifspdu.h: Replace zero-length array with flexible-array member
  CIFS: Warn less noisily on default mount
  fs/cifs: fix gcc warning in sid_to_id
  cifs: allow unlock flock and OFD lock across fork
  cifs: do d_move in rename
  cifs: add SMB2_open() arg to return POSIX data
  cifs: plumb smb2 POSIX dir enumeration
  cifs: add smb2 POSIX info level
  ...

23 files changed, 673 insertions, 232 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 716574aab3b6..ae421634aa42 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -342,7 +342,7 @@ static int
 sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
 		struct cifs_fattr *fattr, uint sidtype)
 {
-	int rc;
+	int rc = 0;
 	struct key *sidkey;
 	char *sidstr;
 	const struct cred *saved_cred;
@@ -450,11 +450,12 @@ out_revert_creds:
 	 * fails then we just fall back to using the mnt_uid/mnt_gid.
 	 */
 got_valid_id:
+	rc = 0;
 	if (sidtype == SIDOWNER)
 		fattr->cf_uid = fuid;
 	else
 		fattr->cf_gid = fgid;
-	return 0;
+	return rc;
 }
 
 int
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index fa77fe5258b0..94e3ed4850b5 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -1018,7 +1018,7 @@ struct file_system_type cifs_fs_type = {
 	.name = "cifs",
 	.mount = cifs_do_mount,
 	.kill_sb = cifs_kill_sb,
-	/*  .fs_flags */
+	.fs_flags = FS_RENAME_DOES_D_MOVE,
 };
 MODULE_ALIAS_FS("cifs");
 
@@ -1027,7 +1027,7 @@ static struct file_system_type smb3_fs_type = {
 	.name = "smb3",
 	.mount = smb3_do_mount,
 	.kill_sb = cifs_kill_sb,
-	/*  .fs_flags */
+	.fs_flags = FS_RENAME_DOES_D_MOVE,
 };
 MODULE_ALIAS_FS("smb3");
 MODULE_ALIAS("smb3");
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index b87456bae1a1..c9e2e6bbca13 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -156,5 +156,5 @@ extern int cifs_truncate_page(struct address_space *mapping, loff_t from);
 extern const struct export_operations cifs_export_ops;
 #endif /* CONFIG_CIFS_NFSD_EXPORT */
 
-#define CIFS_VERSION   "2.25"
+#define CIFS_VERSION   "2.26"
 #endif				/* _CIFSFS_H */
diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index 79d842e7240c..593d826820c3 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -1021,7 +1021,7 @@ typedef struct smb_com_writex_req {
 	__le16 ByteCount;
 	__u8 Pad;		/* BB check for whether padded to DWORD
 				   boundary and optimum performance here */
-	char Data[0];
+	char Data[];
 } __attribute__((packed)) WRITEX_REQ;
 
 typedef struct smb_com_write_req {
@@ -1041,7 +1041,7 @@ typedef struct smb_com_write_req {
 	__le16 ByteCount;
 	__u8 Pad;		/* BB check for whether padded to DWORD
 				   boundary and optimum performance here */
-	char Data[0];
+	char Data[];
 } __attribute__((packed)) WRITE_REQ;
 
 typedef struct smb_com_write_rsp {
@@ -1306,7 +1306,7 @@ typedef struct smb_com_ntransact_req {
 	/* SetupCount words follow then */
 	__le16 ByteCount;
 	__u8 Pad[3];
-	__u8 Parms[0];
+	__u8 Parms[];
 } __attribute__((packed)) NTRANSACT_REQ;
 
 typedef struct smb_com_ntransact_rsp {
@@ -1523,7 +1523,7 @@ struct file_notify_information {
 	__le32 NextEntryOffset;
 	__le32 Action;
 	__le32 FileNameLength;
-	__u8  FileName[0];
+	__u8  FileName[];
 } __attribute__((packed));
 
 /* For IO_REPARSE_TAG_SYMLINK */
@@ -1536,7 +1536,7 @@ struct reparse_symlink_data {
 	__le16	PrintNameOffset;
 	__le16	PrintNameLength;
 	__le32	Flags;
-	char	PathBuffer[0];
+	char	PathBuffer[];
 } __attribute__((packed));
 
 /* Flag above */
@@ -1553,7 +1553,7 @@ struct reparse_posix_data {
 	__le16	ReparseDataLength;
 	__u16	Reserved;
 	__le64	InodeType; /* LNK, FIFO, CHR etc. */
-	char	PathBuffer[0];
+	char	PathBuffer[];
 } __attribute__((packed));
 
 struct cifs_quota_data {
@@ -1691,6 +1691,7 @@ struct smb_t2_rsp {
 #define SMB_FIND_FILE_ID_FULL_DIR_INFO    0x105
 #define SMB_FIND_FILE_ID_BOTH_DIR_INFO    0x106
 #define SMB_FIND_FILE_UNIX                0x202
+#define SMB_FIND_FILE_POSIX_INFO          0x064
 
 typedef struct smb_com_transaction2_qpi_req {
 	struct smb_hdr hdr;	/* wct = 14+ */
@@ -1761,7 +1762,7 @@ struct set_file_rename {
 	__le32 overwrite;   /* 1 = overwrite dest */
 	__u32 root_fid;   /* zero */
 	__le32 target_name_len;
-	char  target_name[0];  /* Must be unicode */
+	char  target_name[];  /* Must be unicode */
 } __attribute__((packed));
 
 struct smb_com_transaction2_sfi_req {
@@ -2450,7 +2451,7 @@ struct cifs_posix_acl { /* access conrol list  (ACL) */
 	__le16	version;
 	__le16	access_entry_count;  /* access ACL - count of entries */
 	__le16	default_entry_count; /* default ACL - count of entries */
-	struct cifs_posix_ace ace_array[0];
+	struct cifs_posix_ace ace_array[];
 	/* followed by
 	struct cifs_posix_ace default_ace_arraay[] */
 } __attribute__((packed));  /* level 0x204 */
@@ -2756,7 +2757,7 @@ typedef struct file_xattr_info {
 	/* BB do we need another field for flags? BB */
 	__u32 xattr_name_len;
 	__u32 xattr_value_len;
-	char  xattr_name[0];
+	char  xattr_name[];
 	/* followed by xattr_value[xattr_value_len], no pad */
 } __attribute__((packed)) FILE_XATTR_INFO; /* extended attribute info
 					      level 0x205 */
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index e5cb681ec138..12a895e02db4 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -602,6 +602,11 @@ int smb2_parse_query_directory(struct cifs_tcon *tcon, struct kvec *rsp_iov,
 			       int resp_buftype,
 			       struct cifs_search_info *srch_inf);
 
+struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server);
+void cifs_put_tcp_super(struct super_block *sb);
+int update_super_prepath(struct cifs_tcon *tcon, const char *prefix,
+			 size_t prefix_len);
+
 #ifdef CONFIG_CIFS_DFS_UPCALL
 static inline int get_dfs_path(const unsigned int xid, struct cifs_ses *ses,
 			       const char *old_path,
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 6f6fb3606a5d..140efc1a9374 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -162,9 +162,18 @@ static int __cifs_reconnect_tcon(const struct nls_table *nlsc,
 
 	for (it = dfs_cache_get_tgt_iterator(&tl); it;
 	     it = dfs_cache_get_next_tgt(&tl, it)) {
-		const char *tgt = dfs_cache_get_tgt_name(it);
+		const char *share, *prefix;
+		size_t share_len, prefix_len;
 
-		extract_unc_hostname(tgt, &dfs_host, &dfs_host_len);
+		rc = dfs_cache_get_tgt_share(it, &share, &share_len, &prefix,
+					     &prefix_len);
+		if (rc) {
+			cifs_dbg(VFS, "%s: failed to parse target share %d\n",
+				 __func__, rc);
+			continue;
+		}
+
+		extract_unc_hostname(share, &dfs_host, &dfs_host_len);
 
 		if (dfs_host_len != tcp_host_len
 		    || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
@@ -175,11 +184,13 @@ static int __cifs_reconnect_tcon(const struct nls_table *nlsc,
 			continue;
 		}
 
-		scnprintf(tree, MAX_TREE_SIZE, "\\%s", tgt);
+		scnprintf(tree, MAX_TREE_SIZE, "\\%.*s", (int)share_len, share);
 
 		rc = CIFSTCon(0, tcon->ses, tree, tcon, nlsc);
-		if (!rc)
+		if (!rc) {
+			rc = update_super_prepath(tcon, prefix, prefix_len);
 			break;
+		}
 		if (rc == -EREMOTE)
 			break;
 	}
@@ -320,7 +331,7 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command)
 	atomic_inc(&tconInfoReconnectCount);
 
 	/* tell server Unix caps we support */
-	if (ses->capabilities & CAP_UNIX)
+	if (cap_unix(ses))
 		reset_cifs_unix_caps(0, tcon, NULL, NULL);
 
 	/*
@@ -1591,7 +1602,6 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	if (server->ops->is_session_expired &&
 	    server->ops->is_session_expired(buf)) {
 		cifs_reconnect(server);
-		wake_up(&server->response_q);
 		return -1;
 	}
 
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 4804d1df8c1c..95b3ab0ca8c0 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -21,6 +21,7 @@
 #include <linux/fs.h>
 #include <linux/net.h>
 #include <linux/string.h>
+#include <linux/sched/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/list.h>
 #include <linux/wait.h>
@@ -57,7 +58,6 @@
 #include "smb2proto.h"
 #include "smbdirect.h"
 #include "dns_resolve.h"
-#include "cifsfs.h"
 #ifdef CONFIG_CIFS_DFS_UPCALL
 #include "dfs_cache.h"
 #endif
@@ -389,54 +389,7 @@ static inline int reconn_set_ipaddr(struct TCP_Server_Info *server)
 #endif
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
-struct super_cb_data {
-	struct TCP_Server_Info *server;
-	struct super_block *sb;
-};
-
 /* These functions must be called with server->srv_mutex held */
-
-static void super_cb(struct super_block *sb, void *arg)
-{
-	struct super_cb_data *d = arg;
-	struct cifs_sb_info *cifs_sb;
-	struct cifs_tcon *tcon;
-
-	if (d->sb)
-		return;
-
-	cifs_sb = CIFS_SB(sb);
-	tcon = cifs_sb_master_tcon(cifs_sb);
-	if (tcon->ses->server == d->server)
-		d->sb = sb;
-}
-
-static struct super_block *get_tcp_super(struct TCP_Server_Info *server)
-{
-	struct super_cb_data d = {
-		.server = server,
-		.sb = NULL,
-	};
-
-	iterate_supers_type(&cifs_fs_type, super_cb, &d);
-
-	if (unlikely(!d.sb))
-		return ERR_PTR(-ENOENT);
-	/*
-	 * Grab an active reference in order to prevent automounts (DFS links)
-	 * of expiring and then freeing up our cifs superblock pointer while
-	 * we're doing failover.
-	 */
-	cifs_sb_active(d.sb);
-	return d.sb;
-}
-
-static inline void put_tcp_super(struct super_block *sb)
-{
-	if (!IS_ERR_OR_NULL(sb))
-		cifs_sb_deactive(sb);
-}
-
 static void reconn_inval_dfs_target(struct TCP_Server_Info *server,
 				    struct cifs_sb_info *cifs_sb,
 				    struct dfs_cache_tgt_list *tgt_list,
@@ -508,7 +461,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
 	server->nr_targets = 1;
 #ifdef CONFIG_CIFS_DFS_UPCALL
 	spin_unlock(&GlobalMid_Lock);
-	sb = get_tcp_super(server);
+	sb = cifs_get_tcp_super(server);
 	if (IS_ERR(sb)) {
 		rc = PTR_ERR(sb);
 		cifs_dbg(FYI, "%s: will not do DFS failover: rc = %d\n",
@@ -535,8 +488,9 @@ cifs_reconnect(struct TCP_Server_Info *server)
 		spin_unlock(&GlobalMid_Lock);
 #ifdef CONFIG_CIFS_DFS_UPCALL
 		dfs_cache_free_tgts(&tgt_list);
-		put_tcp_super(sb);
+		cifs_put_tcp_super(sb);
 #endif
+		wake_up(&server->response_q);
 		return rc;
 	} else
 		server->tcpStatus = CifsNeedReconnect;
@@ -666,11 +620,12 @@ cifs_reconnect(struct TCP_Server_Info *server)
 
 	}
 
-	put_tcp_super(sb);
+	cifs_put_tcp_super(sb);
 #endif
 	if (server->tcpStatus == CifsNeedNegotiate)
 		mod_delayed_work(cifsiod_wq, &server->echo, 0);
 
+	wake_up(&server->response_q);
 	return rc;
 }
 
@@ -765,7 +720,6 @@ server_unresponsive(struct TCP_Server_Info *server)
 		cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 			 (3 * server->echo_interval) / HZ);
 		cifs_reconnect(server);
-		wake_up(&server->response_q);
 		return true;
 	}
 
@@ -898,7 +852,6 @@ is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 		 */
 		cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 		cifs_reconnect(server);
-		wake_up(&server->response_q);
 		break;
 	default:
 		cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
@@ -1070,7 +1023,6 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 		server->vals->header_preamble_size) {
 		cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
 		cifs_reconnect(server);
-		wake_up(&server->response_q);
 		return -ECONNABORTED;
 	}
 
@@ -1118,7 +1070,6 @@ cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	if (server->ops->is_session_expired &&
 	    server->ops->is_session_expired(buf)) {
 		cifs_reconnect(server);
-		wake_up(&server->response_q);
 		return -1;
 	}
 
@@ -1164,8 +1115,9 @@ cifs_demultiplex_thread(void *p)
 	struct task_struct *task_to_wake = NULL;
 	struct mid_q_entry *mids[MAX_COMPOUND];
 	char *bufs[MAX_COMPOUND];
+	unsigned int noreclaim_flag;
 
-	current->flags |= PF_MEMALLOC;
+	noreclaim_flag = memalloc_noreclaim_save();
 	cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
 
 	length = atomic_inc_return(&tcpSesAllocCount);
@@ -1212,7 +1164,6 @@ next_pdu:
 			cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
 				 server->pdu_size);
 			cifs_reconnect(server);
-			wake_up(&server->response_q);
 			continue;
 		}
 
@@ -1320,6 +1271,7 @@ next_pdu:
 		set_current_state(TASK_RUNNING);
 	}
 
+	memalloc_noreclaim_restore(noreclaim_flag);
 	module_put_and_exit(0);
 }
 
@@ -1522,6 +1474,9 @@ cifs_parse_smb_version(char *value, struct smb_vol *vol, bool is_smb3)
 			cifs_dbg(VFS, "vers=1.0 (cifs) not permitted when mounting with smb3\n");
 			return 1;
 		}
+		cifs_dbg(VFS, "Use of the less secure dialect vers=1.0 "
+			   "is not recommended unless required for "
+			   "access to very old servers\n");
 		vol->ops = &smb1_operations;
 		vol->vals = &smb1_values;
 		break;
@@ -2517,11 +2472,12 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 		pr_notice("CIFS: ignoring forcegid mount option specified with no gid= option.\n");
 
 	if (got_version == false)
-		pr_warn("No dialect specified on mount. Default has changed to "
-			"a more secure dialect, SMB2.1 or later (e.g. SMB3), from CIFS "
-			"(SMB1). To use the less secure SMB1 dialect to access "
-			"old servers which do not support SMB3 (or SMB2.1) specify vers=1.0"
-			" on mount.\n");
+		pr_warn_once("No dialect specified on mount. Default has changed"
+			" to a more secure dialect, SMB2.1 or later (e.g. "
+			"SMB3.1.1), from CIFS (SMB1). To use the less secure "
+			"SMB1 dialect to access old servers which do not "
+			"support SMB3.1.1 (or even SMB3 or SMB2.1) specify "
+			"vers=1.0 on mount.\n");
 
 	kfree(mountdata_copy);
 	return 0;
@@ -4999,6 +4955,15 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol)
 	 * dentry revalidation to think the dentry are stale (ESTALE).
 	 */
 	cifs_autodisable_serverino(cifs_sb);
+	/*
+	 * Force the use of prefix path to support failover on DFS paths that
+	 * resolve to targets that have different prefix paths.
+	 */
+	cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
+	kfree(cifs_sb->prepath);
+	cifs_sb->prepath = vol->prepath;
+	vol->prepath = NULL;
+
 out:
 	free_xid(xid);
 	cifs_try_adding_channels(ses);
diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
index 43c1b43a07ec..a67f88bf7ae1 100644
--- a/fs/cifs/dfs_cache.c
+++ b/fs/cifs/dfs_cache.c
@@ -1260,6 +1260,44 @@ void dfs_cache_del_vol(const char *fullpath)
 	kref_put(&vi->refcnt, vol_release);
 }
 
+/**
+ * dfs_cache_get_tgt_share - parse a DFS target
+ *
+ * @it: DFS target iterator.
+ * @share: tree name.
+ * @share_len: length of tree name.
+ * @prefix: prefix path.
+ * @prefix_len: length of prefix path.
+ *
+ * Return zero if target was parsed correctly, otherwise non-zero.
+ */
+int dfs_cache_get_tgt_share(const struct dfs_cache_tgt_iterator *it,
+			    const char **share, size_t *share_len,
+			    const char **prefix, size_t *prefix_len)
+{
+	char *s, sep;
+
+	if (!it || !share || !share_len || !prefix || !prefix_len)
+		return -EINVAL;
+
+	sep = it->it_name[0];
+	if (sep != '\\' && sep != '/')
+		return -EINVAL;
+
+	s = strchr(it->it_name + 1, sep);
+	if (!s)
+		return -EINVAL;
+
+	s = strchrnul(s + 1, sep);
+
+	*share = it->it_name;
+	*share_len = s - it->it_name;
+	*prefix = *s ? s + 1 : s;
+	*prefix_len = &it->it_name[strlen(it->it_name)] - *prefix;
+
+	return 0;
+}
+
 /* Get all tcons that are within a DFS namespace and can be refreshed */
 static void get_tcons(struct TCP_Server_Info *server, struct list_head *head)
 {
diff --git a/fs/cifs/dfs_cache.h b/fs/cifs/dfs_cache.h
index 99ee44f8ad07..bf94d08cfb5a 100644
--- a/fs/cifs/dfs_cache.h
+++ b/fs/cifs/dfs_cache.h
@@ -49,6 +49,10 @@ extern int dfs_cache_update_vol(const char *fullpath,
 				struct TCP_Server_Info *server);
 extern void dfs_cache_del_vol(const char *fullpath);
 
+extern int dfs_cache_get_tgt_share(const struct dfs_cache_tgt_iterator *it,
+				   const char **share, size_t *share_len,
+				   const char **prefix, size_t *prefix_len);
+
 static inline struct dfs_cache_tgt_iterator *
 dfs_cache_get_next_tgt(struct dfs_cache_tgt_list *tl,
 		       struct dfs_cache_tgt_iterator *it)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 8f9d849a0012..5920820bfbd0 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3841,7 +3841,7 @@ again:
 	if (rc == -ENODATA)
 		rc = 0;
 
-	ctx->rc = (rc == 0) ? ctx->total_len : rc;
+	ctx->rc = (rc == 0) ? (ssize_t)ctx->total_len : rc;
 
 	mutex_unlock(&ctx->aio_mutex);
 
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index b16f8d23e97b..8d01ec2dca66 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1835,6 +1835,8 @@ cifs_do_rename(const unsigned int xid, struct dentry *from_dentry,
 		CIFSSMBClose(xid, tcon, fid.netfid);
 	}
 do_rename_exit:
+	if (rc == 0)
+		d_move(from_dentry, to_dentry);
 	cifs_put_tlink(tlink);
 	return rc;
 }
@@ -2148,8 +2150,9 @@ int cifs_getattr(const struct path *path, struct kstat *stat,
 	 * We need to be sure that all dirty pages are written and the server
 	 * has actual ctime, mtime and file length.
 	 */
-	if (!CIFS_CACHE_READ(CIFS_I(inode)) && inode->i_mapping &&
-	    inode->i_mapping->nrpages != 0) {
+	if ((request_mask & (STATX_CTIME | STATX_MTIME | STATX_SIZE)) &&
+	    !CIFS_CACHE_READ(CIFS_I(inode)) &&
+	    inode->i_mapping && inode->i_mapping->nrpages != 0) {
 		rc = filemap_fdatawait(inode->i_mapping);
 		if (rc) {
 			mapping_set_error(inode->i_mapping, rc);
@@ -2157,9 +2160,20 @@ int cifs_getattr(const struct path *path, struct kstat *stat,
 		}
 	}
 
-	rc = cifs_revalidate_dentry_attr(dentry);
-	if (rc)
-		return rc;
+	if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_FORCE_SYNC)
+		CIFS_I(inode)->time = 0; /* force revalidate */
+
+	/*
+	 * If the caller doesn't require syncing, only sync if
+	 * necessary (e.g. due to earlier truncate or setattr
+	 * invalidating the cached metadata)
+	 */
+	if (((flags & AT_STATX_SYNC_TYPE) != AT_STATX_DONT_SYNC) ||
+	    (CIFS_I(inode)->time == 0)) {
+		rc = cifs_revalidate_dentry_attr(dentry);
+		if (rc)
+			return rc;
+	}
 
 	generic_fillattr(inode, stat);
 	stat->blksize = cifs_sb->bsize;
@@ -2516,25 +2530,26 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 
 	/*
 	 * Attempt to flush data before changing attributes. We need to do
-	 * this for ATTR_SIZE and ATTR_MTIME for sure, and if we change the
-	 * ownership or mode then we may also need to do this. Here, we take
-	 * the safe way out and just do the flush on all setattr requests. If
-	 * the flush returns error, store it to report later and continue.
+	 * this for ATTR_SIZE and ATTR_MTIME.  If the flush of the data
+	 * returns error, store it to report later and continue.
 	 *
 	 * BB: This should be smarter. Why bother flushing pages that
 	 * will be truncated anyway? Also, should we error out here if
-	 * the flush returns error?
+	 * the flush returns error? Do we need to check for ATTR_MTIME_SET flag?
 	 */
-	rc = filemap_write_and_wait(inode->i_mapping);
-	if (is_interrupt_error(rc)) {
-		rc = -ERESTARTSYS;
-		goto cifs_setattr_exit;
+	if (attrs->ia_valid & (ATTR_MTIME | ATTR_SIZE | ATTR_CTIME)) {
+		rc = filemap_write_and_wait(inode->i_mapping);
+		if (is_interrupt_error(rc)) {
+			rc = -ERESTARTSYS;
+			goto cifs_setattr_exit;
+		}
+		mapping_set_error(inode->i_mapping, rc);
 	}
 
-	mapping_set_error(inode->i_mapping, rc);
 	rc = 0;
 
-	if (attrs->ia_valid & ATTR_MTIME) {
+	if ((attrs->ia_valid & ATTR_MTIME) &&
+	    !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
 		rc = cifs_get_writable_file(cifsInode, FIND_WR_ANY, &wfile);
 		if (!rc) {
 			tcon = tlink_tcon(wfile->tlink);
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 852aa00ec729..a25ef35b023e 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -416,7 +416,7 @@ smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	}
 
 	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
-		       NULL);
+		       NULL, NULL);
 	if (rc)
 		goto qmf_out_open_fail;
 
@@ -470,7 +470,7 @@ smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	oparms.reconnect = false;
 
 	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
-		       NULL);
+		       NULL, NULL);
 	if (rc) {
 		kfree(utf16_path);
 		return rc;
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 40ca394fd5de..a456febd4109 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -31,6 +31,7 @@
 #include "nterr.h"
 #include "cifs_unicode.h"
 #include "smb2pdu.h"
+#include "cifsfs.h"
 
 extern mempool_t *cifs_sm_req_poolp;
 extern mempool_t *cifs_req_poolp;
@@ -1022,3 +1023,82 @@ int copy_path_name(char *dst, const char *src)
 	name_len++;
 	return name_len;
 }
+
+struct super_cb_data {
+	struct TCP_Server_Info *server;
+	struct super_block *sb;
+};
+
+static void super_cb(struct super_block *sb, void *arg)
+{
+	struct super_cb_data *d = arg;
+	struct cifs_sb_info *cifs_sb;
+	struct cifs_tcon *tcon;
+
+	if (d->sb)
+		return;
+
+	cifs_sb = CIFS_SB(sb);
+	tcon = cifs_sb_master_tcon(cifs_sb);
+	if (tcon->ses->server == d->server)
+		d->sb = sb;
+}
+
+struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server)
+{
+	struct super_cb_data d = {
+		.server = server,
+		.sb = NULL,
+	};
+
+	iterate_supers_type(&cifs_fs_type, super_cb, &d);
+
+	if (unlikely(!d.sb))
+		return ERR_PTR(-ENOENT);
+	/*
+	 * Grab an active reference in order to prevent automounts (DFS links)
+	 * of expiring and then freeing up our cifs superblock pointer while
+	 * we're doing failover.
+	 */
+	cifs_sb_active(d.sb);
+	return d.sb;
+}
+
+void cifs_put_tcp_super(struct super_block *sb)
+{
+	if (!IS_ERR_OR_NULL(sb))
+		cifs_sb_deactive(sb);
+}
+
+int update_super_prepath(struct cifs_tcon *tcon, const char *prefix,
+			 size_t prefix_len)
+{
+	struct super_block *sb;
+	struct cifs_sb_info *cifs_sb;
+	int rc = 0;
+
+	sb = cifs_get_tcp_super(tcon->ses->server);
+	if (IS_ERR(sb))
+		return PTR_ERR(sb);
+
+	cifs_sb = CIFS_SB(sb);
+
+	kfree(cifs_sb->prepath);
+
+	if (*prefix && prefix_len) {
+		cifs_sb->prepath = kstrndup(prefix, prefix_len, GFP_ATOMIC);
+		if (!cifs_sb->prepath) {
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
+	} else
+		cifs_sb->prepath = NULL;
+
+	cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
+
+out:
+	cifs_put_tcp_super(sb);
+	return rc;
+}
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index ba9dadf3be24..19e4a5d3b4ca 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -32,6 +32,7 @@
 #include "cifs_debug.h"
 #include "cifs_fs_sb.h"
 #include "cifsfs.h"
+#include "smb2proto.h"
 
 /*
  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
@@ -217,6 +218,60 @@ cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 	}
 }
 
+/* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
+static void
+cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
+		    struct cifs_sb_info *cifs_sb)
+{
+	struct smb2_posix_info_parsed parsed;
+
+	posix_info_parse(info, NULL, &parsed);
+
+	memset(fattr, 0, sizeof(*fattr));
+	fattr->cf_uniqueid = le64_to_cpu(info->Inode);
+	fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
+	fattr->cf_eof = le64_to_cpu(info->EndOfFile);
+
+	fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
+	fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
+	fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
+
+	fattr->cf_nlink = le32_to_cpu(info->HardLinks);
+	fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
+
+	/*
+	 * Since we set the inode type below we need to mask off
+	 * to avoid strange results if bits set above.
+	 * XXX: why not make server&client use the type bits?
+	 */
+	fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT;
+
+	cifs_dbg(VFS, "XXX dev %d, reparse %d, mode %o",
+		 le32_to_cpu(info->DeviceId),
+		 le32_to_cpu(info->ReparseTag),
+		 le32_to_cpu(info->Mode));
+
+	if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
+		fattr->cf_mode |= S_IFDIR;
+		fattr->cf_dtype = DT_DIR;
+	} else {
+		/*
+		 * mark anything that is not a dir as regular
+		 * file. special files should have the REPARSE
+		 * attribute and will be marked as needing revaluation
+		 */
+		fattr->cf_mode |= S_IFREG;
+		fattr->cf_dtype = DT_REG;
+	}
+
+	if (reparse_file_needs_reval(fattr))
+		fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
+
+	/* TODO map SIDs */
+	fattr->cf_uid = cifs_sb->mnt_uid;
+	fattr->cf_gid = cifs_sb->mnt_gid;
+}
+
 static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
 {
 	const FILE_DIRECTORY_INFO *fi = info;
@@ -359,6 +414,8 @@ ffirst_retry:
 	/* if (cap_unix(tcon->ses) { */
 	if (tcon->unix_ext)
 		cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
+	else if (tcon->posix_extensions)
+		cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
 	else if ((tcon->ses->capabilities &
 		  tcon->ses->server->vals->cap_nt_find) == 0) {
 		cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
@@ -451,6 +508,23 @@ struct cifs_dirent {
 	u64		ino;
 };
 
+static void cifs_fill_dirent_posix(struct cifs_dirent *de,
+				   const struct smb2_posix_info *info)
+{
+	struct smb2_posix_info_parsed parsed;
+
+	/* payload should have already been checked at this point */
+	if (posix_info_parse(info, NULL, &parsed) < 0) {
+		cifs_dbg(VFS, "invalid POSIX info payload");
+		return;
+	}
+
+	de->name = parsed.name;
+	de->namelen = parsed.name_len;
+	de->resume_key = info->Ignored;
+	de->ino = le64_to_cpu(info->Inode);
+}
+
 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 		const FILE_UNIX_INFO *info, bool is_unicode)
 {
@@ -511,6 +585,9 @@ static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 	memset(de, 0, sizeof(*de));
 
 	switch (level) {
+	case SMB_FIND_FILE_POSIX_INFO:
+		cifs_fill_dirent_posix(de, info);
+		break;
 	case SMB_FIND_FILE_UNIX:
 		cifs_fill_dirent_unix(de, info, is_unicode);
 		break;
@@ -786,6 +863,11 @@ static int cifs_filldir(char *find_entry, struct file *file,
 	}
 
 	switch (file_info->srch_inf.info_level) {
+	case SMB_FIND_FILE_POSIX_INFO:
+		cifs_posix_to_fattr(&fattr,
+				    (struct smb2_posix_info *)find_entry,
+				    cifs_sb);
+		break;
 	case SMB_FIND_FILE_UNIX:
 		cifs_unix_basic_to_fattr(&fattr,
 					 &((FILE_UNIX_INFO *)find_entry)->basic,
diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c
index afe1f03aabe3..2fa3ba354cc9 100644
--- a/fs/cifs/smb2file.c
+++ b/fs/cifs/smb2file.c
@@ -62,7 +62,7 @@ smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
 	smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
 
 	rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL,
-		       NULL);
+		       NULL, NULL);
 	if (rc)
 		goto out;
 
@@ -152,7 +152,12 @@ smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 		    (li->offset + li->length))
 			continue;
 		if (current->tgid != li->pid)
-			continue;
+			/*
+			 * flock and OFD lock are associated with an open
+			 * file description, not the process.
+			 */
+			if (!(flock->fl_flags & (FL_FLOCK | FL_OFDLCK)))
+				continue;
 		if (cinode->can_cache_brlcks) {
 			/*
 			 * We can cache brlock requests - simply remove a lock
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index cfe9b800ea8c..b36c46f48705 100644
--- a/fs/cifs/smb2ops.c
+++