From: Paulo Alcantara <paulo@xxxxxxxx>
After a successful failover in cifs_reconnect(), the smb2_reconnect()
function will make sure to reconnect every tcon to new target server.
For SMB2+.
Signed-off-by: Paulo Alcantara <palcantara@xxxxxxx>
Signed-off-by: Aurelien Aptel <aaptel@xxxxxxxx>
---
fs/cifs/cifsproto.h | 2 ++
fs/cifs/misc.c | 17 +++++++++++
fs/cifs/smb2pdu.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++--
3 files changed, 104 insertions(+), 3 deletions(-)
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index f277bc5a0c4e..336c116995d7 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -565,6 +565,8 @@ void cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc);
extern void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
unsigned int *len, unsigned int *offset);
+void extract_unc_hostname(const char *unc, const char **h, size_t *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/misc.c b/fs/cifs/misc.c
index 1e1bf1759247..113980dba4d8 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -946,3 +946,20 @@ void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
else if (page == 0)
*len = rqst->rq_pagesz - rqst->rq_offset;
}
+
+void extract_unc_hostname(const char *unc, const char **h, size_t *len)
+{
+ const char *end;
+
+ /* skip initial slashes */
+ while (*unc && (*unc == '\\' || *unc == '/'))
+ unc++;
+
+ end = unc;
+
+ while (*end && !(*end == '\\' || *end == '/'))
+ end++;
+
+ *h = unc;
+ *len = end - unc;
+}
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 27f86537a5d1..e360d84b1b4f 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -50,6 +50,9 @@
#include "cifs_spnego.h"
#include "smbdirect.h"
#include "trace.h"
+#ifdef CONFIG_CIFS_DFS_UPCALL
+#include "dfs_cache.h"
+#endif
/*
* The following table defines the expected "StructureSize" of SMB2 requests
@@ -152,6 +155,77 @@ smb2_hdr_assemble(struct smb2_sync_hdr *shdr, __le16 smb2_cmd,
return;
}
+#ifdef CONFIG_CIFS_DFS_UPCALL
+static int __smb2_reconnect(const struct nls_table *nlsc,
+ struct cifs_tcon *tcon)
+{
+ int rc;
+ struct dfs_cache_tgt_list tl;
+ struct dfs_cache_tgt_iterator *it = NULL;
+ char tree[MAX_TREE_SIZE + 1];
+ const char *tcp_host;
+ size_t tcp_host_len;
+ const char *dfs_host;
+ size_t dfs_host_len;
+
+ if (tcon->ipc) {
+ snprintf(tree, sizeof(tree), "\\\\%s\\IPC$",
+ tcon->ses->server->hostname);
+ return SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
+ }
+
+ if (!tcon->dfs_path)
+ return SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nlsc);
+
+ rc = dfs_cache_noreq_find(tcon->dfs_path + 1, NULL, &tl);
+ if (rc)
+ return rc;
+
+ extract_unc_hostname(tcon->ses->server->hostname, &tcp_host,
+ &tcp_host_len);
+
+ 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);
+
+ extract_unc_hostname(tgt, &dfs_host, &dfs_host_len);
+
+ if (dfs_host_len != tcp_host_len
+ || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
+ cifs_dbg(FYI, "%s: skipping %.*s, doesn't match %.*s",
+ __func__,
+ (int)dfs_host_len, dfs_host,
+ (int)tcp_host_len, tcp_host);
+ continue;
+ }
+
+ snprintf(tree, sizeof(tree), "\\%s", tgt);
+
+ rc = SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
+ if (!rc)
+ break;
+ if (rc == -EREMOTE)
+ break;
+ }
+
+ if (!rc) {
+ if (it)
+ rc = dfs_cache_noreq_update_tgthint(tcon->dfs_path + 1,
+ it);
+ else
+ rc = -ENOENT;
+ }
+ dfs_cache_free_tgts(&tl);
+ return rc;
+}
+#else
+static inline int __smb2_reconnect(const struct nls_table *nlsc,
+ struct cifs_tcon *tcon)
+{
+ return SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nlsc);
+}
+#endif
+
static int
smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
{
@@ -159,6 +233,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
struct nls_table *nls_codepage;
struct cifs_ses *ses;
struct TCP_Server_Info *server;
+ int retries;
/*
* SMB2s NegProt, SessSetup, Logoff do not have tcon yet so
@@ -192,9 +267,12 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
ses = tcon->ses;
server = ses->server;
+ retries = server->nr_targets;
+
/*
- * Give demultiplex thread up to 10 seconds to reconnect, should be
- * greater than cifs socket timeout which is 7 seconds
+ * Give demultiplex thread up to 10 seconds to each target available for
+ * reconnect -- should be greater than cifs socket timeout which is 7
+ * seconds.
*/
while (server->tcpStatus == CifsNeedReconnect) {
/*
@@ -225,6 +303,9 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
if (server->tcpStatus != CifsNeedReconnect)
break;
+ if (--retries)
+ continue;
+
/*
* on "soft" mounts we wait once. Hard mounts keep
* retrying until process is killed or server comes
@@ -234,6 +315,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
cifs_dbg(FYI, "gave up waiting on reconnect in smb_init\n");
return -EHOSTDOWN;
}
+ retries = server->nr_targets;
}
if (!tcon->ses->need_reconnect && !tcon->need_reconnect)
@@ -271,7 +353,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
if (tcon->use_persistent)
tcon->need_reopen_files = true;
- rc = SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nls_codepage);
+ rc = __smb2_reconnect(nls_codepage, tcon);
mutex_unlock(&tcon->ses->session_mutex);
cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
--
2.13.7
