2011/4/8 Steve French <smfrench@xxxxxxxxx>: > Update on cifs vs. smb2 mids, and the smb2 sendrcv2. Jeff had > suggested more closely matching the cifs and smb2 mids, in particular > extending the 16 bit cifs mid (multiplex identifier for inflight > network requests) to the 64 bit size needed for smb2 (and thus masking > the mid when used for cifs) and having cifs ignore the various smb2 > unique fields in the mid (which makes the mid larger for cifs). > Since the smb2 code in cifs-2.6.git (put in February and early March) > has now been rereviewed, the next step in the smb2 merge is posting > and reviewing the transport routine for smb2 (smb2_sendrcv2 or reusing > cifs_sendrcv2) - the latter may make more sense if we go to a common > mid for cifs and smb2. At the fs summit, Jeff and Jeremy and I > talked about this, but Pavel and others may have opinions on this > topic. As soon as the cifs merge activity settles down for 2.6.39, I > plan to post sendrcv2 alternatives and then begin work with Pavel on > the superblock, file and inode routines and seeing whether for smb2 > they should be smb2 unique (as we originally expected since smb2 is > handle based, and simpler) and look more like they did in the smb2.ko > work that Pavel did last summer or should be more common with the cifs > routines. > > -- > Thanks, > > Steve > -- > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > I suggest to make cifs and smb2 protocol mid structures use common structure that has equals fields for both and then expand this structure for protocol-dependent things. It can look like this: /* one of these for every pending CIFS request to the server */ struct mid_q_entry { __u8 protocol_id; struct list_head qhead; /* mids waiting on reply from this server */ int midState; /* wish this were enum but can not pass to wait_event */ unsigned long when_alloc; /* when mid was created */ #ifdef CONFIG_CIFS_STATS2 unsigned long when_sent; /* time when smb send finished */ unsigned long when_received; /* when demux complete (taken off wire) */ #endif bool largeBuf:1; /* if valid response, is pointer to large buf */ void *resp_buf; /* response buffer */ mid_callback_t *callback; /* call completion callback */ void *callback_data; /* general purpose pointer for callback */ }; struct cifs_mid_q_entry { struct mid_q_entry mid_q; __u16 mid; /* multiplex id */ __u32 sequence_number; /* for CIFS signing */ __u8 command; /* smb command code */ __u16 pid; /* process id */ bool multiRsp:1; /* multiple trans2 responses for one request */ bool multiEnd:1; /* both received */ }; struct smb2_mid_q_entry { struct mid_q_entry mid_q; __u64 mid; /* multiplex id(s), bigger for smb2 */ __le16 command; /* smb2 command code */ __u32 pid; /* process id - bigger for smb2 than cifs */ }; So, we always work with a pointer to common structure mid_q_entry and then expand it according to protocol_id filed when we need it: #define PROTOCOL_ID(mid) (*((__u8 *)mid)) process_mid(struct mid_q_entry *pmid) { if (PROTOCOL_ID(pmid) == SMB2) process_smb2_mid((struct smb2_mid_q_entry *)pmid); else process_cifs_mid((struct cifs_mid_q_entry *)pmid); } -- Best regards, Pavel Shilovsky. -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
