From: Paulo Alcantara (SUSE) pc@cjr.nz
commit 84a1f5b1cc6fd7f6cd99fc5630c36f631b19fa60 upstream.
We used to skip reconnects on all SMB2_IOCTL commands due to SMB3+ FSCTL_VALIDATE_NEGOTIATE_INFO - which made sense since we're still establishing a SMB session.
However, when refresh_cache_worker() calls smb2_get_dfs_refer() and we're under reconnect, SMB2_ioctl() will not be able to get a proper status error (e.g. -EHOSTDOWN in case we failed to reconnect) but an -EAGAIN from cifs_send_recv() thus looping forever in refresh_cache_worker().
Fixes: e99c63e4d86d ("SMB3: Fix deadlock in validate negotiate hits reconnect") Signed-off-by: Paulo Alcantara (SUSE) pc@cjr.nz Suggested-by: Aurelien Aptel aaptel@suse.com Reviewed-by: Aurelien Aptel aaptel@suse.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/cifs/smb2pdu.c | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-)
--- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -252,7 +252,7 @@ smb2_reconnect(__le16 smb2_command, stru if (tcon == NULL) return 0;
- if (smb2_command == SMB2_TREE_CONNECT || smb2_command == SMB2_IOCTL) + if (smb2_command == SMB2_TREE_CONNECT) return 0;
if (tcon->tidStatus == CifsExiting) { @@ -426,16 +426,9 @@ fill_small_buf(__le16 smb2_command, stru * SMB information in the SMB header. If the return code is zero, this * function must have filled in request_buf pointer. */ -static int -smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon, - void **request_buf, unsigned int *total_len) +static int __smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon, + void **request_buf, unsigned int *total_len) { - int rc; - - rc = smb2_reconnect(smb2_command, tcon); - if (rc) - return rc; - /* BB eventually switch this to SMB2 specific small buf size */ if (smb2_command == SMB2_SET_INFO) *request_buf = cifs_buf_get(); @@ -456,7 +449,31 @@ smb2_plain_req_init(__le16 smb2_command, cifs_stats_inc(&tcon->num_smbs_sent); }
- return rc; + return 0; +} + +static int smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon, + void **request_buf, unsigned int *total_len) +{ + int rc; + + rc = smb2_reconnect(smb2_command, tcon); + if (rc) + return rc; + + return __smb2_plain_req_init(smb2_command, tcon, request_buf, + total_len); +} + +static int smb2_ioctl_req_init(u32 opcode, struct cifs_tcon *tcon, + void **request_buf, unsigned int *total_len) +{ + /* Skip reconnect only for FSCTL_VALIDATE_NEGOTIATE_INFO IOCTLs */ + if (opcode == FSCTL_VALIDATE_NEGOTIATE_INFO) { + return __smb2_plain_req_init(SMB2_IOCTL, tcon, request_buf, + total_len); + } + return smb2_plain_req_init(SMB2_IOCTL, tcon, request_buf, total_len); }
/* For explanation of negotiate contexts see MS-SMB2 section 2.2.3.1 */ @@ -2661,7 +2678,7 @@ SMB2_ioctl_init(struct cifs_tcon *tcon, int rc; char *in_data_buf;
- rc = smb2_plain_req_init(SMB2_IOCTL, tcon, (void **) &req, &total_len); + rc = smb2_ioctl_req_init(opcode, tcon, (void **) &req, &total_len); if (rc) return rc;