9p: Implement TLOCK

Synopsis

    size[4] TLock tag[2] fid[4] flock[n]
    size[4] RLock tag[2] status[1]

Description

Tlock is used to acquire/release byte range posix locks on a file
identified by given fid. The reply contains status of the lock request

    flock structure:
        type[1] - Type of lock: F_RDLCK, F_WRLCK, F_UNLCK
        flags[4] - Flags could be either of
          P9_LOCK_FLAGS_BLOCK - Blocked lock request, if there is a
            conflicting lock exists, wait for that lock to be released.
          P9_LOCK_FLAGS_RECLAIM - Reclaim lock request, used when client is
            trying to reclaim a lock after a server restrart (due to crash)
        start[8] - Starting offset for lock
        length[8] - Number of bytes to lock
          If length is 0, lock all bytes starting at the location 'start'
          through to the end of file
        pid[4] - PID of the process that wants to take lock
        client_id[4] - Unique client id

        status[1] - Status of the lock request, can be
          P9_LOCK_SUCCESS(0), P9_LOCK_BLOCKED(1), P9_LOCK_ERROR(2) or
          P9_LOCK_GRACE(3)
          P9_LOCK_SUCCESS - Request was successful
          P9_LOCK_BLOCKED - A conflicting lock is held by another process
          P9_LOCK_ERROR - Error while processing the lock request
          P9_LOCK_GRACE - Server is in grace period, it can't accept new lock
            requests in this period (except locks with
            P9_LOCK_FLAGS_RECLAIM flag set)

Signed-off-by: M. Mohan Kumar <[email protected]>
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Venkateswararao Jujjuri <[email protected]>
Signed-off-by: Eric Van Hensbergen <[email protected]>
This commit is contained in:
M. Mohan Kumar 2010-09-27 11:34:24 +05:30 • committed by Eric Van Hensbergen
commit a099027c77
5 changed files with 222 additions and 2 deletions

View file

@ -1803,3 +1803,36 @@ error:
}
EXPORT_SYMBOL(p9_client_mkdir_dotl);
int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
{
int err;
struct p9_client *clnt;
struct p9_req_t *req;
err = 0;
clnt = fid->clnt;
P9_DPRINTK(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
"start %lld length %lld proc_id %d client_id %s\n",
fid->fid, flock->type, flock->flags, flock->start,
flock->length, flock->proc_id, flock->client_id);
req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
flock->flags, flock->start, flock->length,
flock->proc_id, flock->client_id);
if (IS_ERR(req))
return PTR_ERR(req);
err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
if (err) {
p9pdu_dump(1, req->rc);
goto error;
}
P9_DPRINTK(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
error:
p9_free_req(clnt, req);
return err;
}
EXPORT_SYMBOL(p9_client_lock_dotl);