From: Paulo Alcantara pc@manguebit.com
[ Upstream commit 1bcd548d935a33c6fc58331405eb1b82fd6150de ]
Make sure to get an up-to-date TCP_Server_Info::nr_targets value prior to waiting the server to be reconnected in cifs_reconnect_tcon(). It is set in cifs_tcp_ses_needs_reconnect() and protected by TCP_Server_Info::srv_lock.
Create a new cifs_wait_for_server_reconnect() helper that can be used by both SMB2+ and CIFS reconnect code.
Signed-off-by: Paulo Alcantara (SUSE) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com Stable-dep-of: bc962159e8e3 ("cifs: avoid race conditions with parallel reconnects") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/cifsproto.h | 1 + fs/cifs/cifssmb.c | 43 ++---------------------- fs/cifs/misc.c | 44 ++++++++++++++++++++++++ fs/cifs/smb2pdu.c | 82 ++++++++++++--------------------------------- 4 files changed, 69 insertions(+), 101 deletions(-)
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index e75184544ecb4..639df85dafd6c 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -697,5 +697,6 @@ static inline int cifs_create_options(struct cifs_sb_info *cifs_sb, int options)
struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon); void cifs_put_tcon_super(struct super_block *sb); +int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry);
#endif /* _CIFSPROTO_H */ diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 566e6a26b897c..5ca4a5383aaae 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -70,7 +70,6 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) struct cifs_ses *ses; struct TCP_Server_Info *server; struct nls_table *nls_codepage; - int retries;
/* * SMBs NegProt, SessSetup, uLogoff do not have tcon yet so check for @@ -98,45 +97,9 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) } spin_unlock(&tcon->tc_lock);
- retries = server->nr_targets; - - /* - * 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) { - rc = wait_event_interruptible_timeout(server->response_q, - (server->tcpStatus != CifsNeedReconnect), - 10 * HZ); - if (rc < 0) { - cifs_dbg(FYI, "%s: aborting reconnect due to a received signal by the process\n", - __func__); - return -ERESTARTSYS; - } - - /* are we still trying to reconnect? */ - spin_lock(&server->srv_lock); - if (server->tcpStatus != CifsNeedReconnect) { - spin_unlock(&server->srv_lock); - break; - } - spin_unlock(&server->srv_lock); - - if (retries && --retries) - continue; - - /* - * on "soft" mounts we wait once. Hard mounts keep - * retrying until process is killed or server comes - * back on-line - */ - if (!tcon->retry) { - cifs_dbg(FYI, "gave up waiting on reconnect in smb_init\n"); - return -EHOSTDOWN; - } - retries = server->nr_targets; - } + rc = cifs_wait_for_server_reconnect(server, tcon->retry); + if (rc) + return rc;
spin_lock(&ses->chan_lock); if (!cifs_chan_needs_reconnect(ses, server) && !tcon->need_reconnect) { diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 9f4486b705d5c..5542893ef03f7 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -1376,3 +1376,47 @@ int cifs_inval_name_dfs_link_error(const unsigned int xid, return 0; } #endif + +int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry) +{ + int timeout = 10; + int rc; + + spin_lock(&server->srv_lock); + if (server->tcpStatus != CifsNeedReconnect) { + spin_unlock(&server->srv_lock); + return 0; + } + timeout *= server->nr_targets; + spin_unlock(&server->srv_lock); + + /* + * Give demultiplex thread up to 10 seconds to each target available for + * reconnect -- should be greater than cifs socket timeout which is 7 + * seconds. + * + * On "soft" mounts we wait once. Hard mounts keep retrying until + * process is killed or server comes back on-line. + */ + do { + rc = wait_event_interruptible_timeout(server->response_q, + (server->tcpStatus != CifsNeedReconnect), + timeout * HZ); + if (rc < 0) { + cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n", + __func__); + return -ERESTARTSYS; + } + + /* are we still trying to reconnect? */ + spin_lock(&server->srv_lock); + if (server->tcpStatus != CifsNeedReconnect) { + spin_unlock(&server->srv_lock); + return 0; + } + spin_unlock(&server->srv_lock); + } while (retry); + + cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__); + return -EHOSTDOWN; +} diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 6e6e44d8b4c79..83d04cd2f9df8 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -139,66 +139,6 @@ smb2_hdr_assemble(struct smb2_hdr *shdr, __le16 smb2_cmd, return; }
-static int wait_for_server_reconnect(struct TCP_Server_Info *server, - __le16 smb2_command, bool retry) -{ - int timeout = 10; - int rc; - - spin_lock(&server->srv_lock); - if (server->tcpStatus != CifsNeedReconnect) { - spin_unlock(&server->srv_lock); - return 0; - } - timeout *= server->nr_targets; - spin_unlock(&server->srv_lock); - - /* - * Return to caller for TREE_DISCONNECT and LOGOFF and CLOSE - * here since they are implicitly done when session drops. - */ - switch (smb2_command) { - /* - * BB Should we keep oplock break and add flush to exceptions? - */ - case SMB2_TREE_DISCONNECT: - case SMB2_CANCEL: - case SMB2_CLOSE: - case SMB2_OPLOCK_BREAK: - return -EAGAIN; - } - - /* - * Give demultiplex thread up to 10 seconds to each target available for - * reconnect -- should be greater than cifs socket timeout which is 7 - * seconds. - * - * On "soft" mounts we wait once. Hard mounts keep retrying until - * process is killed or server comes back on-line. - */ - do { - rc = wait_event_interruptible_timeout(server->response_q, - (server->tcpStatus != CifsNeedReconnect), - timeout * HZ); - if (rc < 0) { - cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n", - __func__); - return -ERESTARTSYS; - } - - /* are we still trying to reconnect? */ - spin_lock(&server->srv_lock); - if (server->tcpStatus != CifsNeedReconnect) { - spin_unlock(&server->srv_lock); - return 0; - } - spin_unlock(&server->srv_lock); - } while (retry); - - cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__); - return -EHOSTDOWN; -} - static int smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon, struct TCP_Server_Info *server) @@ -239,7 +179,27 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon, (!tcon->ses->server) || !server) return -EIO;
- rc = wait_for_server_reconnect(server, smb2_command, tcon->retry); + spin_lock(&server->srv_lock); + if (server->tcpStatus == CifsNeedReconnect) { + /* + * Return to caller for TREE_DISCONNECT and LOGOFF and CLOSE + * here since they are implicitly done when session drops. + */ + switch (smb2_command) { + /* + * BB Should we keep oplock break and add flush to exceptions? + */ + case SMB2_TREE_DISCONNECT: + case SMB2_CANCEL: + case SMB2_CLOSE: + case SMB2_OPLOCK_BREAK: + spin_unlock(&server->srv_lock); + return -EAGAIN; + } + } + spin_unlock(&server->srv_lock); + + rc = cifs_wait_for_server_reconnect(server, tcon->retry); if (rc) return rc;