From 3b7952109361c684caf0c50474da8662ecc81019 Mon Sep 17 00:00:00 2001 From: Steve French Date: Thu, 13 Nov 2008 19:45:32 +0000 Subject: [CIFS] Fix cifs reconnection flags In preparation for Jeff's big umount/mount fixes to remove the possibility of various races in cifs mount and linked list handling of sessions, sockets and tree connections, this patch cleans up some repetitive code in cifs_mount, and addresses a problem with ses->status and tcon->tidStatus in which we were overloading the "need_reconnect" state with other status in that field. So the "need_reconnect" flag has been broken out from those two state fields (need reconnect was not mutually exclusive from some of the other possible tid and ses states). In addition, a few exit cases in cifs_mount were cleaned up, and a problem with a tcon flag (for lease support) was not being set consistently for the 2nd mount of the same share CC: Jeff Layton CC: Shirish Pargaonkar Signed-off-by: Steve French --- fs/cifs/cifssmb.c | 40 ++++++++++++++++++++++------------------ 1 file changed, 22 insertions(+), 18 deletions(-) (limited to 'fs/cifs/cifssmb.c') diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index d5eac48fc41..7f0651b6957 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -190,10 +190,10 @@ small_smb_init(int smb_command, int wct, struct cifsTconInfo *tcon, /* need to prevent multiple threads trying to simultaneously reconnect the same SMB session */ down(&tcon->ses->sesSem); - if (tcon->ses->status == CifsNeedReconnect) + if (tcon->ses->need_reconnect) rc = cifs_setup_session(0, tcon->ses, nls_codepage); - if (!rc && (tcon->tidStatus == CifsNeedReconnect)) { + if (!rc && (tcon->need_reconnect)) { mark_open_files_invalid(tcon); rc = CIFSTCon(0, tcon->ses, tcon->treeName, tcon, nls_codepage); @@ -295,7 +295,7 @@ smb_init(int smb_command, int wct, struct cifsTconInfo *tcon, check for tcp and smb session status done differently for those three - in the calling routine */ if (tcon) { - if (tcon->tidStatus == CifsExiting) { + if (tcon->need_reconnect) { /* only tree disconnect, open, and write, (and ulogoff which does not have tcon) are allowed as we start force umount */ @@ -337,10 +337,10 @@ smb_init(int smb_command, int wct, struct cifsTconInfo *tcon, /* need to prevent multiple threads trying to simultaneously reconnect the same SMB session */ down(&tcon->ses->sesSem); - if (tcon->ses->status == CifsNeedReconnect) + if (tcon->ses->need_reconnect) rc = cifs_setup_session(0, tcon->ses, nls_codepage); - if (!rc && (tcon->tidStatus == CifsNeedReconnect)) { + if (!rc && (tcon->need_reconnect)) { mark_open_files_invalid(tcon); rc = CIFSTCon(0, tcon->ses, tcon->treeName, tcon, nls_codepage); @@ -759,7 +759,7 @@ CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon) /* No need to return error on this operation if tid invalidated and closed on server already e.g. due to tcp session crashing */ - if (tcon->tidStatus == CifsNeedReconnect) { + if (tcon->need_reconnect) { up(&tcon->tconSem); return 0; } @@ -806,32 +806,36 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses) up(&ses->sesSem); return -EBUSY; } + + if (ses->server == NULL) + return -EIO; + + if (ses->need_reconnect) + goto session_already_dead; /* no need to send SMBlogoff if uid + already closed due to reconnect */ rc = small_smb_init(SMB_COM_LOGOFF_ANDX, 2, NULL, (void **)&pSMB); if (rc) { up(&ses->sesSem); return rc; } - if (ses->server) { - pSMB->hdr.Mid = GetNextMid(ses->server); + pSMB->hdr.Mid = GetNextMid(ses->server); - if (ses->server->secMode & + if (ses->server->secMode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) pSMB->hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE; - } pSMB->hdr.Uid = ses->Suid; pSMB->AndXCommand = 0xFF; rc = SendReceiveNoRsp(xid, ses, (struct smb_hdr *) pSMB, 0); - if (ses->server) { - atomic_dec(&ses->server->socketUseCount); - if (atomic_read(&ses->server->socketUseCount) == 0) { - spin_lock(&GlobalMid_Lock); - ses->server->tcpStatus = CifsExiting; - spin_unlock(&GlobalMid_Lock); - rc = -ESHUTDOWN; - } +session_already_dead: + atomic_dec(&ses->server->socketUseCount); + if (atomic_read(&ses->server->socketUseCount) == 0) { + spin_lock(&GlobalMid_Lock); + ses->server->tcpStatus = CifsExiting; + spin_unlock(&GlobalMid_Lock); + rc = -ESHUTDOWN; } up(&ses->sesSem); -- cgit From e7ddee9037e7dd43de1ad08b51727e552aedd836 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 14 Nov 2008 13:44:38 -0500 Subject: cifs: disable sharing session and tcon and add new TCP sharing code The code that allows these structs to be shared is extremely racy. Disable the sharing of SMB and tcon structs for now until we can come up with a way to do this that's race free. We want to continue to share TCP sessions, however since they are required for multiuser mounts. For that, implement a new (hopefully race-free) scheme. Add a new global list of TCP sessions, and take care to get a reference to it whenever we're dealing with one. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifssmb.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'fs/cifs/cifssmb.c') diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 7f0651b6957..cd9e9a145e4 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -664,8 +664,9 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses) rc = -EIO; goto neg_err_exit; } - - if (server->socketUseCount.counter > 1) { + read_lock(&cifs_tcp_ses_lock); + if (server->srv_count > 1) { + read_unlock(&cifs_tcp_ses_lock); if (memcmp(server->server_GUID, pSMBr->u.extended_response. GUID, 16) != 0) { @@ -674,9 +675,11 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses) pSMBr->u.extended_response.GUID, 16); } - } else + } else { + read_unlock(&cifs_tcp_ses_lock); memcpy(server->server_GUID, pSMBr->u.extended_response.GUID, 16); + } if (count == 16) { server->secType = RawNTLMSSP; @@ -830,12 +833,9 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses) pSMB->AndXCommand = 0xFF; rc = SendReceiveNoRsp(xid, ses, (struct smb_hdr *) pSMB, 0); session_already_dead: - atomic_dec(&ses->server->socketUseCount); - if (atomic_read(&ses->server->socketUseCount) == 0) { - spin_lock(&GlobalMid_Lock); - ses->server->tcpStatus = CifsExiting; - spin_unlock(&GlobalMid_Lock); - rc = -ESHUTDOWN; + if (ses->server) { + cifs_put_tcp_session(ses->server); + rc = 0; } up(&ses->sesSem); -- cgit From 14fbf50d695207754daeb96270b3027a3821121f Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 14 Nov 2008 13:53:46 -0500 Subject: cifs: reinstate sharing of SMB sessions sans races We do this by abandoning the global list of SMB sessions and instead moving to a per-server list. This entails adding a new list head to the TCP_Server_Info struct. The refcounting for the cifsSesInfo is moved to a non-atomic variable. We have to protect it by a lock anyway, so there's no benefit to making it an atomic. The list and refcount are protected by the global cifs_tcp_ses_lock. The patch also adds a new routines to find and put SMB sessions and that properly take and put references under the lock. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifssmb.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) (limited to 'fs/cifs/cifssmb.c') diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index cd9e9a145e4..9c95617baa4 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -799,20 +799,16 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses) int rc = 0; cFYI(1, ("In SMBLogoff for session disconnect")); - if (ses) - down(&ses->sesSem); - else - return -EIO; - - atomic_dec(&ses->inUse); - if (atomic_read(&ses->inUse) > 0) { - up(&ses->sesSem); - return -EBUSY; - } - if (ses->server == NULL) + /* + * BB: do we need to check validity of ses and server? They should + * always be valid since we have an active reference. If not, that + * should probably be a BUG() + */ + if (!ses || !ses->server) return -EIO; + down(&ses->sesSem); if (ses->need_reconnect) goto session_already_dead; /* no need to send SMBlogoff if uid already closed due to reconnect */ @@ -833,10 +829,6 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses) pSMB->AndXCommand = 0xFF; rc = SendReceiveNoRsp(xid, ses, (struct smb_hdr *) pSMB, 0); session_already_dead: - if (ses->server) { - cifs_put_tcp_session(ses->server); - rc = 0; - } up(&ses->sesSem); /* if session dead then we do not need to do ulogoff, -- cgit From f1987b44f642e96176adc88b7ce23a1d74806f89 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Sat, 15 Nov 2008 11:12:47 -0500 Subject: cifs: reinstate sharing of tree connections Use a similar approach to the SMB session sharing. Add a list of tcons attached to each SMB session. Move the refcount to non-atomic. Protect all of the above with the cifs_tcp_ses_lock. Add functions to properly find and put references to the tcons. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifssmb.c | 43 ++++++++++++------------------------------- 1 file changed, 12 insertions(+), 31 deletions(-) (limited to 'fs/cifs/cifssmb.c') diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 9c95617baa4..e6bb2d9d5b0 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -742,50 +742,31 @@ CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon) int rc = 0; cFYI(1, ("In tree disconnect")); - /* - * If last user of the connection and - * connection alive - disconnect it - * If this is the last connection on the server session disconnect it - * (and inside session disconnect we should check if tcp socket needs - * to be freed and kernel thread woken up). - */ - if (tcon) - down(&tcon->tconSem); - else - return -EIO; - atomic_dec(&tcon->useCount); - if (atomic_read(&tcon->useCount) > 0) { - up(&tcon->tconSem); - return -EBUSY; - } + /* BB: do we need to check this? These should never be NULL. */ + if ((tcon->ses == NULL) || (tcon->ses->server == NULL)) + return -EIO; - /* No need to return error on this operation if tid invalidated and - closed on server already e.g. due to tcp session crashing */ - if (tcon->need_reconnect) { - up(&tcon->tconSem); + /* + * No need to return error on this operation if tid invalidated and + * closed on server already e.g. due to tcp session crashing. Also, + * the tcon is no longer on the list, so no need to take lock before + * checking this. + */ + if (tcon->need_reconnect) return 0; - } - if ((tcon->ses == NULL) || (tcon->ses->server == NULL)) { - up(&tcon->tconSem); - return -EIO; - } rc = small_smb_init(SMB_COM_TREE_DISCONNECT, 0, tcon, (void **)&smb_buffer); - if (rc) { - up(&tcon->tconSem); + if (rc) return rc; - } rc = SendReceiveNoRsp(xid, tcon->ses, smb_buffer, 0); if (rc) cFYI(1, ("Tree disconnect failed %d", rc)); - up(&tcon->tconSem); - /* No need to return error on this operation if tid invalidated and - closed on server already e.g. due to tcp session crashing */ + closed on server already e.g. due to tcp session crashing */ if (rc == -EAGAIN) rc = 0; -- cgit From 2c55608f28444c3f33b10312881384c470ceed56 Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Thu, 23 Oct 2008 13:58:42 +0400 Subject: Fixed parsing of mount options when doing DFS submount Since these hit the same routines, and are relatively small, it is easier to review them as one patch. Fixed incorrect handling of the last option in some cases Fixed prefixpath handling convert path_consumed into host depended string length (in bytes) Use non default separator if it is provided in the original mount options Acked-by: Jeff Layton Signed-off-by: Igor Mammedov Signed-off-by: Steve French --- fs/cifs/cifssmb.c | 39 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 3 deletions(-) (limited to 'fs/cifs/cifssmb.c') diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index e6bb2d9d5b0..bdda46dd435 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -3899,6 +3899,27 @@ GetInodeNumOut: return rc; } +/* computes length of UCS string converted to host codepage + * @src: UCS string + * @maxlen: length of the input string in UCS characters + * (not in bytes) + * + * return: size of input string in host codepage + */ +static int hostlen_fromUCS(const __le16 *src, const int maxlen, + const struct nls_table *nls_codepage) { + int i; + int hostlen = 0; + char to[4]; + int charlen; + for (i = 0; (i < maxlen) && src[i]; ++i) { + charlen = nls_codepage->uni2char(le16_to_cpu(src[i]), + to, NLS_MAX_CHARSET_SIZE); + hostlen += charlen > 0 ? charlen : 1; + } + return hostlen; +} + /* parses DFS refferal V3 structure * caller is responsible for freeing target_nodes * returns: @@ -3909,7 +3930,8 @@ static int parse_DFS_referrals(TRANSACTION2_GET_DFS_REFER_RSP *pSMBr, unsigned int *num_of_nodes, struct dfs_info3_param **target_nodes, - const struct nls_table *nls_codepage) + const struct nls_table *nls_codepage, int remap, + const char *searchName) { int i, rc = 0; char *data_end; @@ -3960,7 +3982,17 @@ parse_DFS_referrals(TRANSACTION2_GET_DFS_REFER_RSP *pSMBr, struct dfs_info3_param *node = (*target_nodes)+i; node->flags = le16_to_cpu(pSMBr->DFSFlags); - node->path_consumed = le16_to_cpu(pSMBr->PathConsumed); + if (is_unicode) { + __le16 *tmp = kmalloc(strlen(searchName)*2, GFP_KERNEL); + cifsConvertToUCS((__le16 *) tmp, searchName, + PATH_MAX, nls_codepage, remap); + node->path_consumed = hostlen_fromUCS(tmp, + le16_to_cpu(pSMBr->PathConsumed)/2, + nls_codepage); + kfree(tmp); + } else + node->path_consumed = le16_to_cpu(pSMBr->PathConsumed); + node->server_type = le16_to_cpu(ref->ServerType); node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags); @@ -4093,7 +4125,8 @@ getDFSRetry: /* parse returned result into more usable form */ rc = parse_DFS_referrals(pSMBr, num_of_nodes, - target_nodes, nls_codepage); + target_nodes, nls_codepage, remap, + searchName); GetDFSRefExit: cifs_buf_release(pSMB); -- cgit From bfb59820ee46616a7bdb4af6b8f7e109646de6ec Mon Sep 17 00:00:00 2001 From: Steve French Date: Tue, 18 Nov 2008 16:33:48 +0000 Subject: [CIFS] fix check for dead tcon in smb_init This was recently changed to check for need_reconnect, but should actually be a check for a tidStatus of CifsExiting. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifssmb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/cifs/cifssmb.c') diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index bdda46dd435..2af8626ced4 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -295,7 +295,7 @@ smb_init(int smb_command, int wct, struct cifsTconInfo *tcon, check for tcp and smb session status done differently for those three - in the calling routine */ if (tcon) { - if (tcon->need_reconnect) { + if (tcon->tidStatus == CifsExiting) { /* only tree disconnect, open, and write, (and ulogoff which does not have tcon) are allowed as we start force umount */ -- cgit