Since many servers (Windows clients, and non-clustered servers) do not
support persistent handles but do support resilient handles, allow
the user to specify a mount option "resilienthandles" in order
to get more reliable connections and less chance of data loss
(at least when SMB2.1 or later)
Signed-off-by: Steve French <steve.french@xxxxxxxxxxxxxxx>
Signed-off-by: Steve French <steve.french@xxxxxxxxxxxxxxx>
---
fs/cifs/cifsfs.c | 2 ++
fs/cifs/cifsglob.h | 2 ++
fs/cifs/connect.c | 24 +++++++++++++++++++++++-
fs/cifs/smb2file.c | 6 ++++++
4 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 13302e9..f578ef9 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -456,6 +456,8 @@ cifs_show_options(struct seq_file *s, struct dentry *root)
seq_puts(s, ",hard");
if (tcon->use_persistent)
seq_puts(s, ",persistenthandles");
+ else if (tcon->use_resilient)
+ seq_puts(s, ",resilienthandles");
if (tcon->unix_ext)
seq_puts(s, ",unix");
else
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index ec31a03..472daeb 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -496,6 +496,7 @@ struct smb_vol {
bool nosharesock:1;
bool persistent:1;
bool nopersistent:1;
+ bool resilient:1; /* noresilient not required since not fored for CA */
unsigned int rsize;
unsigned int wsize;
bool sockopt_tcp_nodelay:1;
@@ -901,6 +902,7 @@ struct cifs_tcon {
bool broken_posix_open; /* e.g. Samba server versions < 3.3.2, 3.2.9 */
bool broken_sparse_sup; /* if server or share does not support sparse */
bool need_reconnect:1; /* connection reset, tid now invalid */
+ bool use_resilient:1; /* use resilient instead of durable handles */
bool use_persistent:1; /* use persistent instead of durable handles */
#ifdef CONFIG_CIFS_SMB2
bool print:1; /* set if connection to printer share */
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 9e44532..1e7840a 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -88,6 +88,7 @@ enum {
Opt_fsc, Opt_mfsymlinks,
Opt_multiuser, Opt_sloppy, Opt_nosharesock,
Opt_persistent, Opt_nopersistent,
+ Opt_resilient, Opt_noresilient,
/* Mount options which take numeric value */
Opt_backupuid, Opt_backupgid, Opt_uid,
@@ -172,6 +173,8 @@ static const match_table_t cifs_mount_option_tokens = {
{ Opt_nosharesock, "nosharesock" },
{ Opt_persistent, "persistenthandles"},
{ Opt_nopersistent, "nopersistenthandles"},
+ { Opt_resilient, "resilienthandles"},
+ { Opt_noresilient, "noresilienthandles"},
{ Opt_backupuid, "backupuid=%s" },
{ Opt_backupgid, "backupgid=%s" },
@@ -1510,12 +1513,23 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
break;
case Opt_persistent:
vol->persistent = true;
- if (vol->nopersistent) {
+ if ((vol->nopersistent) || (vol->resilient)) {
cifs_dbg(VFS,
"persistenthandles mount options conflict\n");
goto cifs_parse_mount_err;
}
break;
+ case Opt_resilient:
+ vol->resilient = true;
+ if (vol->persistent) {
+ cifs_dbg(VFS,
+ "persistenthandles mount options conflict\n");
+ goto cifs_parse_mount_err;
+ }
+ break;
+ case Opt_noresilient:
+ vol->resilient = false; /* this is already the default */
+ break;
/* Numeric Values */
case Opt_backupuid:
@@ -2695,6 +2709,14 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
&& (volume_info->nopersistent == false)) {
cifs_dbg(FYI, "enabling persistent handles\n");
tcon->use_persistent = true;
+ } else if (volume_info->resilient) {
+ if (ses->server->vals->protocol_id == 0) {
+ cifs_dbg(VFS,
+ "SMB2.1 or later required for resilient handles\n");
+ rc = -EOPNOTSUPP;
+ goto out_fail;
+ }
+ tcon->use_resilient = true;
}
/*
diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c
index 2ab297d..04f2af0 100644
--- a/fs/cifs/smb2file.c
+++ b/fs/cifs/smb2file.c
@@ -67,6 +67,12 @@ smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
if (rc)
goto out;
+ /*
+ * FIXME: Add
+ * if (tcon->use_resilient)
+ * SMB2_ioctl(xid, ... FSCTL_LMR_REQUEST_RESILIENCY, true);
+ */
+
if (buf) {
/* open response does not have IndexNumber field - get it */
rc = SMB2_get_srv_num(xid, oparms->tcon, fid->persistent_fid,
--
1.9.1
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