current patches for cifs-utils release

* current patches for cifs-utils release
@ 2019-04-04 16:59 Pavel Shilovsky
  2019-04-04 17:16 ` Paulo Alcantara
  0 siblings, 1 reply; 2+ messages in thread
From: Pavel Shilovsky @ 2019-04-04 16:59 UTC (permalink / raw)
  To: Ronnie Sahlberg, Aurélien Aptel, Paulo Alcantara, Steve French
  Cc: linux-cifs

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Hi all,

for-next branch is updated with the patches in attachments (resulting
of merging some of the patches and fixing up some minor style
problems):

https://github.com/piastry/cifs-utils/commits/next

Please take a look if anything is missed.

--
Best regards,
Pavel Shilovsky

[-- Attachment #2: 0001-smbinfo-Add-ability-to-query-snapshots-previous-vers.patch --]
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From 7cf164b0fbddcc343226df7e096ecd82080f3350 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@microsoft.com>
Date: Fri, 29 Mar 2019 03:05:55 -0500
Subject: [PATCH 1/7] smbinfo: Add ability to query snapshots (previous
 versions)

 "smbinfo list-snapshots"

Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
---
 smbinfo.c   | 108 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 smbinfo.rst |   2 ++
 2 files changed, 109 insertions(+), 1 deletion(-)

diff --git a/smbinfo.c b/smbinfo.c
index 33fca95..adfd85e 100644
--- a/smbinfo.c
+++ b/smbinfo.c
@@ -89,6 +89,8 @@ usage(char *name)
 		"      Prints the security descriptor for a cifs file.\n"
 		"  quota:\n"
 		"      Prints the quota for a cifs file.\n"
+		"  list-snapshots:\n"
+		"      List the previous versions of the volume that backs this file.\n"
 		"  fsctl-getobjid:\n"
 		"      Prints the objectid of the file and GUID of the underlying volume.\n",
 		name);
@@ -882,7 +884,6 @@ print_quota(unsigned char *sd)
 	uint32_t u32, neo;
 	uint64_t u64;
 	struct timeval tv;
-	struct tm;
 	int i, off = 0;
 
 one_more:
@@ -966,6 +967,109 @@ quota(int f)
 	free(qi);
 }
 
+
+struct smb_snapshot_array {
+	int32_t	number_of_snapshots;
+	int32_t	number_of_snapshots_returned;
+	int32_t	snapshot_array_size;
+	char snapshot_data[0];
+};
+
+
+#define GMT_NAME_LEN 24 /* length of a @GMT- name */
+#define GMT_FORMAT "@GMT-%Y.%m.%d-%H.%M.%S"
+
+#define NTFS_TIME_OFFSET ((unsigned long long)(369*365 + 89) * 24 * 3600 * 10000000)
+
+static void print_snapshots(struct smb_snapshot_array *psnap)
+{
+	int current_snapshot_entry = 0;
+	char gmt_token[GMT_NAME_LEN + 1] = {0};
+	int i;
+	int j = 0;
+	struct tm tm;
+	unsigned long long dce_time;
+
+	printf("Number of snapshots: %d Number of snapshots returned: %d\n",
+		psnap->number_of_snapshots,
+		psnap->number_of_snapshots_returned);
+	printf("Snapshot list in GMT (Coordinated UTC Time) and SMB format (100 nanosecond units needed for snapshot mounts):");
+	for (i = 0; i < psnap->snapshot_array_size; i++) {
+		if (psnap->snapshot_data[i] == '@') {
+			j = 0;
+			current_snapshot_entry++;
+			printf("\n%d) GMT:", current_snapshot_entry);
+		}
+		if (psnap->snapshot_data[i] != 0) {
+			gmt_token[j] = psnap->snapshot_data[i];
+			j++;
+		}
+		if (j == GMT_NAME_LEN) {
+			printf("%s", gmt_token);
+			j = 0;
+			strptime(gmt_token, GMT_FORMAT, &tm);
+			dce_time = timegm(&tm) * 10000000 + NTFS_TIME_OFFSET;
+			printf("\n   SMB3:%llu", dce_time);
+		}
+	}
+	printf("\n");
+}
+
+#define CIFS_ENUMERATE_SNAPSHOTS _IOR(CIFS_IOCTL_MAGIC, 6, struct smb_snapshot_array)
+
+#define MIN_SNAPSHOT_ARRAY_SIZE 16 /* See MS-SMB2 section 3.3.5.15.1 */
+
+static void
+list_snapshots(int f)
+{
+
+	struct smb_snapshot_array snap_inf;
+	struct smb_snapshot_array *buf;
+
+	/*
+	 * When first field in structure we pass in here is zero, cifs.ko can
+	 * recognize that this is the first query and that it must set the SMB3
+	 * FSCTL response buffer size (in the request) to exactly 16 bytes
+	 * (which is required by some servers to process the initial query)
+	 */
+	snap_inf.number_of_snapshots = 0;
+	snap_inf.number_of_snapshots_returned = 0;
+	snap_inf.snapshot_array_size = sizeof(struct smb_snapshot_array);
+
+	/* Query the number of snapshots so we know how much to allocate */
+	if (ioctl(f, CIFS_ENUMERATE_SNAPSHOTS, &snap_inf) < 0) {
+		fprintf(stderr, "Querying snapshots failed with %s\n", strerror(errno));
+		exit(1);
+	}
+
+	if (snap_inf.number_of_snapshots == 0)
+		return;
+
+	/* Now that we know the size, query the list from the server */
+
+	buf = malloc(snap_inf.snapshot_array_size + MIN_SNAPSHOT_ARRAY_SIZE);
+
+	if (buf == NULL) {
+		printf("Failed, out of memory.\n");
+		exit(1);
+	}
+	/*
+	 * first parm is non-zero which allows cifs.ko to recognize that this is
+	 * the second query (it has to set response buf size larger)
+	 */
+	buf->number_of_snapshots = snap_inf.number_of_snapshots;
+
+	buf->snapshot_array_size = snap_inf.snapshot_array_size;
+
+	if (ioctl(f, CIFS_ENUMERATE_SNAPSHOTS, buf) < 0) {
+		fprintf(stderr, "Querying snapshots failed with %s\n", strerror(errno));
+		exit(1);
+	}
+
+	print_snapshots(buf);
+	free(buf);
+}
+
 int main(int argc, char *argv[])
 {
 	int c;
@@ -1016,6 +1120,8 @@ int main(int argc, char *argv[])
 		secdesc(f);
 	else if (!strcmp(argv[optind], "quota"))
 		quota(f);
+	else if (!strcmp(argv[optind], "list-snapshots"))
+		list_snapshots(f);
 	else if (!strcmp(argv[1], "fsctl-getobjid"))
 		fsctlgetobjid(f);
 	else {
diff --git a/smbinfo.rst b/smbinfo.rst
index fd7f0ff..0c96050 100644
--- a/smbinfo.rst
+++ b/smbinfo.rst
@@ -64,6 +64,8 @@ COMMAND
 
 `fsctl-getobjid`: Prints the ObjectID
 
+`list-snapshots`: Lists the previous versions of the volume that backs this file
+
 `quota`: Print the quota for the volume in the form
 - SID Length
 - Change Time
-- 
2.7.4


[-- Attachment #3: 0005-mount.cifs-detect-GMT-format-of-snapshot-version.patch --]
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From e8b8bb5fa61c53b05975650194da24786c4a4f32 Mon Sep 17 00:00:00 2001
From: Pavel Shilovsky <pshilov@microsoft.com>
Date: Wed, 3 Apr 2019 22:42:10 +0000
Subject: [PATCH 5/7] mount.cifs: detect GMT format of snapshot version

In order to provide an easy way to access snapshots a GMT
token string should be allowed as a "snapshot" mount option
argument, not SMB 100-nanoseconds time only. Detect if the
argument is in GMT format and convert it to SMB 100-nanoseconds
time before passing to the kernel.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
---
 mount.cifs.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 47 insertions(+), 7 deletions(-)

diff --git a/mount.cifs.c b/mount.cifs.c
index c6a1bd6..b3235e4 100644
--- a/mount.cifs.c
+++ b/mount.cifs.c
@@ -43,6 +43,7 @@
 #include <limits.h>
 #include <paths.h>
 #include <libgen.h>
+#include <time.h>
 #include <sys/mman.h>
 #include <sys/wait.h>
 #ifdef HAVE_SYS_FSUID_H
@@ -161,10 +162,16 @@
 #define OPT_BKUPUID    30
 #define OPT_BKUPGID    31
 #define OPT_NOFAIL     32
+#define OPT_SNAPSHOT   33
 
 #define MNT_TMP_FILE "/.mtab.cifs.XXXXXX"
 
-/* struct for holding parsed mount info for use by privleged process */
+#define GMT_NAME_LEN 24 /* length of a @GMT- name */
+#define GMT_FORMAT "@GMT-%Y.%m.%d-%H.%M.%S"
+
+#define NTFS_TIME_OFFSET ((unsigned long long)(369*365 + 89) * 24 * 3600 * 10000000)
+
+/* struct for holding parsed mount info for use by privileged process */
 struct parsed_mount_info {
 	unsigned long flags;
 	char host[NI_MAXHOST + 1];
@@ -271,9 +278,9 @@ static int mount_usage(FILE * stream)
 	fprintf(stream,
 		"\n\tcache=<strict|none|loose>,nounix,cifsacl,sec=<authentication mechanism>,");
 	fprintf(stream,
-		"\n\tsign,seal,fsc,snapshot=<time>,nosharesock,persistenthandles,resilienthandles,");
+		"\n\tsign,seal,fsc,snapshot=<token|time>,nosharesock,persistenthandles,");
 	fprintf(stream,
-		"\n\trdma,vers=<smb_dialect>,cruid");
+		"\n\tresilienthandles,rdma,vers=<smb_dialect>,cruid");
 	fprintf(stream,
 		"\n\nOptions not needed for servers supporting CIFS Unix extensions");
 	fprintf(stream,
@@ -773,6 +780,8 @@ static int parse_opt_token(const char *token)
 		return OPT_NOFAIL;
 	if (strncmp(token, "x-", 2) == 0)
 		return OPT_IGNORE;
+	if (strncmp(token, "snapshot", 8) == 0)
+		return OPT_SNAPSHOT;
 
 	return OPT_ERROR;
 }
@@ -793,16 +802,19 @@ parse_options(const char *data, struct parsed_mount_info *parsed_info)
 	int got_uid = 0;
 	int got_cruid = 0;
 	int got_gid = 0;
+	int got_snapshot = 0;
 	uid_t uid, cruid = 0, bkupuid = 0;
 	gid_t gid, bkupgid = 0;
 	char *ep;
 	struct passwd *pw;
 	struct group *gr;
 	/*
-	 * max 32-bit uint in decimal is 4294967295 which is 10 chars wide
-	 * +1 for NULL, and +1 for good measure
+	 * max 64-bit uint in decimal is 18446744073709551615 which is 20 chars
+	 * wide +1 for NULL, and +1 for good measure
 	 */
-	char txtbuf[12];
+	char txtbuf[22];
+	unsigned long long snapshot;
+	struct tm tm;
 
 	/* make sure we're starting from beginning */
 	out[0] = '\0';
@@ -1130,6 +1142,19 @@ parse_options(const char *data, struct parsed_mount_info *parsed_info)
 		case OPT_NOFAIL:
 			parsed_info->nofail = 1;
 			goto nocopy;
+		case OPT_SNAPSHOT:
+			if (!value || !*value)
+				goto nocopy;
+			if (strncmp(value, "@GMT-", 5))
+				break;
+			if ((strlen(value) != GMT_NAME_LEN) ||
+			    (strptime(value, GMT_FORMAT, &tm) == NULL)) {
+				fprintf(stderr, "bad snapshot token\n");
+				return EX_USAGE;
+			}
+			snapshot = timegm(&tm) * 10000000 + NTFS_TIME_OFFSET;
+			got_snapshot = 1;
+			goto nocopy;
 		}
 
 		/* check size before copying option to buffer */
@@ -1225,7 +1250,7 @@ nocopy:
 	if (got_bkupgid) {
 		word_len = snprintf(txtbuf, sizeof(txtbuf), "%u", bkupgid);
 
-		/* comma + "backkupgid=" + terminating NULL == 12 */
+		/* comma + "backupgid=" + terminating NULL == 12 */
 		if (out_len + word_len + 12 > MAX_OPTIONS_LEN) {
 			fprintf(stderr, "Options string too long\n");
 			return EX_USAGE;
@@ -1237,6 +1262,21 @@ nocopy:
 		}
 		snprintf(out + out_len, word_len + 11, "backupgid=%s", txtbuf);
 	}
+	if (got_snapshot) {
+		word_len = snprintf(txtbuf, sizeof(txtbuf), "%llu", snapshot);
+
+		/* comma + "snapshot=" + terminating NULL == 11 */
+		if (out_len + word_len + 11 > MAX_OPTIONS_LEN) {
+			fprintf(stderr, "Options string too long\n");
+			return EX_USAGE;
+		}
+
+		if (out_len) {
+			strlcat(out, ",", MAX_OPTIONS_LEN);
+			out_len++;
+		}
+		snprintf(out + out_len, word_len + 11, "snapshot=%s", txtbuf);
+	}
 
 	return 0;
 }
-- 
2.7.4


[-- Attachment #4: 0004-mount.cifs-add-more-options-to-help-message.patch --]
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From 6ef851043c4a36be0b0657d4d3cf3a1ab9be6efb Mon Sep 17 00:00:00 2001
From: Pavel Shilovsky <pshilov@microsoft.com>
Date: Wed, 3 Apr 2019 12:24:33 -0700
Subject: [PATCH 4/7] mount.cifs: add more options to help message

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
---
 mount.cifs.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/mount.cifs.c b/mount.cifs.c
index d921fed..c6a1bd6 100644
--- a/mount.cifs.c
+++ b/mount.cifs.c
@@ -267,13 +267,13 @@ static int mount_usage(FILE * stream)
 	fprintf(stream,
 		"\n\tsep=<char>,iocharset=<codepage>,suid,nosuid,exec,noexec,serverino,");
 	fprintf(stream,
-		"\n\tmapchars,nomapchars,nolock,servernetbiosname=<SRV_RFC1001NAME>");
+		"\n\tnoserverino,mapchars,nomapchars,nolock,servernetbiosname=<SRV_RFC1001NAME>");
 	fprintf(stream,
-		"\n\tdirectio,nounix,cifsacl,sec=<authentication mechanism>,sign,seal,fsc,");
+		"\n\tcache=<strict|none|loose>,nounix,cifsacl,sec=<authentication mechanism>,");
 	fprintf(stream,
-		"\n\tsnapshot=<time>,nosharesock,persistenthandles,resilienthandles,rdma,");
+		"\n\tsign,seal,fsc,snapshot=<time>,nosharesock,persistenthandles,resilienthandles,");
 	fprintf(stream,
-		"\n\tvers=<smb_dialect>,cruid");
+		"\n\trdma,vers=<smb_dialect>,cruid");
 	fprintf(stream,
 		"\n\nOptions not needed for servers supporting CIFS Unix extensions");
 	fprintf(stream,
@@ -290,7 +290,9 @@ static int mount_usage(FILE * stream)
 	fprintf(stream,
 		"\n\tnointr,ignorecase,noposixpaths,noacl,prefixpath=<path>,nobrl,");
 	fprintf(stream,
-		"\n\techo_interval=<seconds>,actimeo=<seconds>,max_credits=<credits>");
+		"\n\techo_interval=<seconds>,actimeo=<seconds>,max_credits=<credits>,");
+	fprintf(stream,
+		"\n\tbsize=<size>");
 	fprintf(stream,
 		"\n\nOptions are described in more detail in the manual page");
 	fprintf(stream, "\n\tman 8 mount.cifs\n");
-- 
2.7.4


[-- Attachment #5: 0002-smbinfo-make-argument-order-consistent.patch --]
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From 213a508997303dfead74154edf9d137e911e84a0 Mon Sep 17 00:00:00 2001
From: Pavel Shilovsky <pshilov@microsoft.com>
Date: Tue, 2 Apr 2019 11:40:40 -0700
Subject: [PATCH 2/7] smbinfo: make argument order consistent

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
---
 smbinfo.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/smbinfo.c b/smbinfo.c
index adfd85e..f9de7fd 100644
--- a/smbinfo.c
+++ b/smbinfo.c
@@ -85,14 +85,14 @@ usage(char *name)
 		"      Prints FilePositionInfo for a cifs file.\n"
 		"  filestandardinfo:\n"
 		"      Prints FileStandardInfo for a cifs file.\n"
-		"  secdesc:\n"
-		"      Prints the security descriptor for a cifs file.\n"
-		"  quota:\n"
-		"      Prints the quota for a cifs file.\n"
+		"  fsctl-getobjid:\n"
+		"      Prints the objectid of the file and GUID of the underlying volume.\n"
 		"  list-snapshots:\n"
 		"      List the previous versions of the volume that backs this file.\n"
-		"  fsctl-getobjid:\n"
-		"      Prints the objectid of the file and GUID of the underlying volume.\n",
+		"  quota:\n"
+		"      Prints the quota for a cifs file.\n"
+		"  secdesc:\n"
+		"      Prints the security descriptor for a cifs file.\n",
 		name);
 	exit(1);
 }
@@ -1116,14 +1116,14 @@ int main(int argc, char *argv[])
 		filepositioninfo(f);
 	else if (!strcmp(argv[optind], "filestandardinfo"))
 		filestandardinfo(f);
-	else if (!strcmp(argv[optind], "secdesc"))
-		secdesc(f);
-	else if (!strcmp(argv[optind], "quota"))
-		quota(f);
+	else if (!strcmp(argv[optind], "fsctl-getobjid"))
+		fsctlgetobjid(f);
 	else if (!strcmp(argv[optind], "list-snapshots"))
 		list_snapshots(f);
-	else if (!strcmp(argv[1], "fsctl-getobjid"))
-		fsctlgetobjid(f);
+	else if (!strcmp(argv[optind], "quota"))
+		quota(f);
+	else if (!strcmp(argv[optind], "secdesc"))
+		secdesc(f);
 	else {
 		fprintf(stderr, "Unknown command %s\n", argv[optind]);
 		exit(1);
-- 
2.7.4


[-- Attachment #6: 0003-mount.cifs-Add-various-missing-parms-from-the-help-t.patch --]
[-- Type: application/octet-stream, Size: 2125 bytes --]

From 6396a77eac26b3bf15f0fdfb187282aa7d0a5bcf Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@microsoft.com>
Date: Tue, 2 Apr 2019 21:18:27 -0500
Subject: [PATCH 3/7] mount.cifs Add various missing parms from the help text

When you type mount.cifs --help there were more than 40 mount parms
missing. Add 12 of the more common ones to what is displayed by help.

Signed-off-by: Steve French <stfrench@microsoft.com>
---
 mount.cifs.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/mount.cifs.c b/mount.cifs.c
index 9370f2e..d921fed 100644
--- a/mount.cifs.c
+++ b/mount.cifs.c
@@ -269,20 +269,28 @@ static int mount_usage(FILE * stream)
 	fprintf(stream,
 		"\n\tmapchars,nomapchars,nolock,servernetbiosname=<SRV_RFC1001NAME>");
 	fprintf(stream,
-		"\n\tdirectio,nounix,cifsacl,sec=<authentication mechanism>,sign,seal,fsc");
+		"\n\tdirectio,nounix,cifsacl,sec=<authentication mechanism>,sign,seal,fsc,");
+	fprintf(stream,
+		"\n\tsnapshot=<time>,nosharesock,persistenthandles,resilienthandles,rdma,");
+	fprintf(stream,
+		"\n\tvers=<smb_dialect>,cruid");
 	fprintf(stream,
 		"\n\nOptions not needed for servers supporting CIFS Unix extensions");
 	fprintf(stream,
 		"\n\t(e.g. unneeded for mounts to most Samba versions):");
 	fprintf(stream,
-		"\n\tuid=<uid>,gid=<gid>,dir_mode=<mode>,file_mode=<mode>,sfu");
+		"\n\tuid=<uid>,gid=<gid>,dir_mode=<mode>,file_mode=<mode>,sfu,");
+	fprintf(stream,
+		"\n\tmfsymlinks,idsfromsid");
 	fprintf(stream, "\n\nRarely used options:");
 	fprintf(stream,
 		"\n\tport=<tcpport>,rsize=<size>,wsize=<size>,unc=<unc_name>,ip=<ip_address>,");
 	fprintf(stream,
 		"\n\tdev,nodev,nouser_xattr,netbiosname=<OUR_RFC1001NAME>,hard,soft,intr,");
 	fprintf(stream,
-		"\n\tnointr,ignorecase,noposixpaths,noacl,prefixpath=<path>,nobrl");
+		"\n\tnointr,ignorecase,noposixpaths,noacl,prefixpath=<path>,nobrl,");
+	fprintf(stream,
+		"\n\techo_interval=<seconds>,actimeo=<seconds>,max_credits=<credits>");
 	fprintf(stream,
 		"\n\nOptions are described in more detail in the manual page");
 	fprintf(stream, "\n\tman 8 mount.cifs\n");
-- 
2.7.4


[-- Attachment #7: 0006-Update-man-page-for-mount.cifs-to-add-new-options.patch --]
[-- Type: application/octet-stream, Size: 9072 bytes --]

From 19c1bb71de9f58bb5b1fbc78ab468f80df62ee57 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@microsoft.com>
Date: Wed, 3 Apr 2019 23:46:34 -0500
Subject: [PATCH 6/7] Update man page for mount.cifs to add new options

Add description of "snapshot" and "handletimeout" mount
options and a security section noting that the use of
cifs is discouraged, and various minor updates.

Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
---
 mount.cifs.rst | 98 +++++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 60 insertions(+), 38 deletions(-)

diff --git a/mount.cifs.rst b/mount.cifs.rst
index f64d1f1..8ba6e7b 100644
--- a/mount.cifs.rst
+++ b/mount.cifs.rst
@@ -15,13 +15,13 @@ SYNOPSIS
 
 This tool is part of the cifs-utils suite.
 
-``mount.cifs`` mounts a Linux CIFS filesystem. It is usually invoked
-indirectly by the mount(8) command when using the "-t cifs"
+``mount.cifs`` mounts a CIFS or SMB3 filesystem from Linux. It is
+usually invoked indirectly by the mount(8) command when using the "-t cifs"
 option. This command only works in Linux, and the kernel must support
-the cifs filesystem. The CIFS protocol is the successor to the SMB
-protocol and is supported by most Windows servers and many other
-commercial servers and Network Attached Storage appliances as well as
-by the popular Open Source server Samba.
+the cifs filesystem. The SMB3 protocol is the successor to the CIFS (SMB)
+protocol and is supported by most Windows servers, Azure (cloud storage),
+Macs and many other commercial servers and Network Attached Storage
+appliances as well as by the popular Open Source server Samba.
 
 The mount.cifs utility attaches the UNC name (exported network
 resource) specified as service (using ``//server/share`` syntax, where
@@ -266,6 +266,13 @@ handlecache
 nohandlecache
   Disable caching of the share root directory handle.
 
+handletimeout=arg
+  The time (in milliseconds) for which the server should reserve the handle after
+  a failover waiting for the client to reconnect.  When mounting with
+  resilienthandles or persistenthandles mount option, or when their use is
+  requested by the server (continuous availability shares) then this parameter
+  overrides the server default handle timeout (which for most servers is 120 seconds).
+
 rwpidforward
   Forward pid of a process who opened a file to any read or write
   operation on that file. This prevent applications like wine(1) from
@@ -387,6 +394,12 @@ persistenthandles
 nopersistenthandles
   (default) Disable persistent handles.
 
+snapshot=time
+   Mount a specific snapshot of the remote share. ``time`` must be a
+   positive integer identifying the snapshot requested (in 100-nanosecond
+   units that have elapsed since January 1, 1601, or alternatively it can
+   be specified in GMT format e.g. @GMT-2019.03.27-20.52.19)
+
 nobrl
   Do not send byte range lock requests to the server. This is necessary
   for certain applications that break with cifs style mandatory byte
@@ -401,7 +414,7 @@ locallease
   Check cached leases locally instead of querying the server.
 
 sfu
-  When the CIFS Unix Extensions are not negotiated, attempt to create
+  When the CIFS or SMB3 Unix Extensions are not negotiated, attempt to create
   device files and fifos in a format compatible with Services for Unix
   (SFU). In addition retrieve bits 10-12 of the mode via the
   ``SETFILEBITS`` extended attribute (as SFU does). In the future the
@@ -450,11 +463,11 @@ noserverino
 
   See section `INODE NUMBERS`_ for more information.
 
-unix|linux
+posix|unix|linux
   (default) Enable Unix Extensions for this mount. Requires CIFS
   (vers=1.0) or SMB3.1.1 (vers=3.1.1) and a server supporting them.
 
-nounix|nolinux
+noposix|nounix|nolinux
   Disable the Unix Extensions for this mount. This can be useful in
   order to turn off multiple settings at once. This includes POSIX acls,
   POSIX locks, POSIX paths, symlink support and retrieving
@@ -479,38 +492,35 @@ nosharesock
   Do not try to reuse sockets if the system is already connected to
   the server via an existing mount point. This will make the client
   always make a new connection to the server no matter what he is
-  already connected to.
+  already connected to. This can be useful in simulating multiple
+  clients connecting to the same server, as each mount point
+  will use a different TCP socket.
 
 noblocksend
   Send data on the socket using non blocking operations (MSG_DONTWAIT flag).
 
 rsize=bytes
   Maximum amount of data that the kernel will request in a read request
-  in bytes. Prior to kernel 3.2.0, the default was 16k, and the maximum
-  size was limited by the ``CIFSMaxBufSize`` module parameter. As of
-  kernel 3.2.0, the behavior varies according to whether POSIX
-  extensions are enabled on the mount and the server supports large
-  POSIX reads. If they are, then the default is 1M, and the maximum is
-  16M. If they are not supported by the server, then the default is 60k
-  and the maximum is around 127k. The reason for the 60k is because it's
-  the maximum size read that windows servers can fill. Note that this
-  value is a maximum, and the client may settle on a smaller size to
-  accommodate what the server supports. In kernels prior to 3.2.0, no
-  negotiation is performed.
+  in bytes. Maximum size that servers will accept is typically 8MB for SMB3
+  or later dialects. Default requested during mount is 4MB. Prior to the 4.20
+  kernel the default requested was 1MB. Prior to the SMB2.1 dialect the
+  maximum was usually 64K.
 
 wsize=bytes
   Maximum amount of data that the kernel will send in a write request in
-  bytes. Prior to kernel 3.0.0, the default and maximum was 57344 (14 \*
-  4096 pages). As of 3.0.0, the default depends on whether the client
-  and server negotiate large writes via POSIX extensions. If they do,
-  then the default is 1M, and the maximum allowed is 16M. If they do
-  not, then the default is 65536 and the maximum allowed is 131007. Note
-  that this value is just a starting point for negotiation in 3.0.0 and
-  up. The client and server may negotiate this size downward according
-  to the server's capabilities. In kernels prior to 3.0.0, no
-  negotiation is performed. It can end up with an existing superblock if
-  this value isn't specified or it's greater or equal than the existing
-  one.
+  bytes. Maximum size that servers will accept is typically 8MB for SMB3
+  or later dialects. Default requested during mount is 4MB. Prior to the 4.20
+  kernel the default requested was 1MB. Prior to the SMB2.1 dialect the
+  maximum was usually 64K.
+
+bsize=bytes
+  Override the default blocksize (1MB) reported on SMB3 files (requires
+  kernel version of 5.1 or later). Prior to kernel version 5.1, the
+  blocksize was always reported as 16K instead of 1MB (and was not
+  configurable) which can hurt the performance of tools like cp and scp
+  (especially for uncached I/O) which decide on the read and write size
+  to use for file copies based on the inode blocksize. bsize may not be
+  less than 16K or greater than 16M.
 
 max_credits=n
   Maximum credits the SMB2 client can have. Default is 32000. Must be
@@ -885,14 +895,26 @@ CONFIGURATION
 The primary mechanism for making configuration changes and for reading
 debug information for the cifs vfs is via the Linux /proc
 filesystem. In the directory */proc/fs/cifs* are various
-configuration files and pseudo files which can display debug
-information. There are additional startup options such as maximum
-buffer size and number of buffers which only may be set when the
+configuration files and pseudo files which can display debug information
+and performance statistics. There are additional startup options such as
+maximum buffer size and number of buffers which only may be set when the
 kernel cifs vfs (cifs.ko module) is loaded. These can be seen by
 running the ``modinfo`` utility against the file cifs.ko which will
 list the options that may be passed to cifs during module installation
 (device driver load). For more information see the kernel file
-*fs/cifs/README*.
+*fs/cifs/README*. When configuring dynamic tracing (trace-cmd)
+note that the list of SMB3 events which can be enabled can be seen at:
+*/sys/kernel/debug/tracing/events/cifs/*.
+
+********
+SECURITY
+********
+
+The use of SMB2.1 or later (including the latest dialect SMB3.1.1)
+is recommended for improved security and SMB1 is no longer requested
+by default at mount time. Old dialects such as CIFS (SMB1, ie vers=1.0)
+have much weaker security. Use of CIFS (SMB1) can be disabled by
+modprobe cifs disable_legacy_dialects=y.
 
 ****
 BUGS
@@ -913,8 +935,8 @@ bugs (minimum: mount.cifs (try ``mount.cifs -V``), kernel (see
 VERSION
 *******
 
-This man page is correct for version 1.74 of the cifs vfs filesystem
-(roughly Linux kernel 3.0).
+This man page is correct for version 2.18 of the cifs vfs filesystem
+(roughly Linux kernel 5.0).
 
 ********
 SEE ALSO
-- 
2.7.4


[-- Attachment #8: 0007-mount.cifs.rst-mention-kernel-version-for-snapshots.patch --]
[-- Type: application/octet-stream, Size: 1005 bytes --]

From 7047e57bcb343ad867728fbddc5a4da29d7ae9fc Mon Sep 17 00:00:00 2001
From: Pavel Shilovsky <pshilov@microsoft.com>
Date: Thu, 4 Apr 2019 16:25:30 +0000
Subject: [PATCH 7/7] mount.cifs.rst: mention kernel version for snapshots

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
---
 mount.cifs.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mount.cifs.rst b/mount.cifs.rst
index 8ba6e7b..02016e0 100644
--- a/mount.cifs.rst
+++ b/mount.cifs.rst
@@ -398,7 +398,8 @@ snapshot=time
    Mount a specific snapshot of the remote share. ``time`` must be a
    positive integer identifying the snapshot requested (in 100-nanosecond
    units that have elapsed since January 1, 1601, or alternatively it can
-   be specified in GMT format e.g. @GMT-2019.03.27-20.52.19)
+   be specified in GMT format e.g. @GMT-2019.03.27-20.52.19). Supported
+   in the Linux kernel starting from v4.19.
 
 nobrl
   Do not send byte range lock requests to the server. This is necessary
-- 
2.7.4


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