From: Paulo Alcantara Date: Wed, 14 Nov 2018 19:20:31 +0000 (-0200) Subject: cifs: Add support for failover in smb2_reconnect() X-Git-Tag: v5.15~7265^2~5 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a3a53b7603798fd875e2afbba7e2b9ba6b19c7c7;p=platform%2Fkernel%2Flinux-starfive.git cifs: Add support for failover in smb2_reconnect() 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 Signed-off-by: Aurelien Aptel Signed-off-by: Steve French --- diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index f277bc5..336c116 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 7c858d4..bee2030 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -952,3 +952,20 @@ 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 67ce339..e283590 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 @@ out: 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);