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9p: Implement TGETLOCK

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Synopsis

    size[4] TGetlock tag[2] fid[4] getlock[n]
    size[4] RGetlock tag[2] getlock[n]

Description

TGetlock is used to test for the existence of byte range posix locks on a file
identified by given fid. The reply contains getlock structure. If the lock could
be placed it returns F_UNLCK in type field of getlock structure.  Otherwise it
returns the details of the conflicting locks in the getlock structure

    getlock structure:
      type[1] - Type of lock: F_RDLCK, F_WRLCK
      start[8] - Starting offset for lock
      length[8] - Number of bytes to check for the lock
             If length is 0, check for lock in all bytes starting at the location
            'start' through to the end of file
      pid[4] - PID of the process that wants to take lock/owns the task
               in case of reply
      client[4] - Client id of the system that owns the process which
                  has the conflicting lock

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This commit is contained in:
M. Mohan Kumar
2010-09-27 12:22:13 +05:30
committed by Eric Van Hensbergen
parent a099027c77
commit 1d769cd192
4 changed files with 100 additions and 0 deletions
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34
net/9p/client.c
View File

@@ -1836,3 +1836,37 @@ error:
}
EXPORT_SYMBOL(p9_client_lock_dotl);
int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
{
int err;
struct p9_client *clnt;
struct p9_req_t *req;
err = 0;
clnt = fid->clnt;
P9_DPRINTK(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
glock->start, glock->length, glock->proc_id, glock->client_id);
req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid, glock->type,
glock->start, glock->length, glock->proc_id, glock->client_id);
if (IS_ERR(req))
return PTR_ERR(req);
err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
&glock->start, &glock->length, &glock->proc_id,
&glock->client_id);
if (err) {
p9pdu_dump(1, req->rc);
goto error;
}
P9_DPRINTK(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
"proc_id %d client_id %s\n", glock->type, glock->start,
glock->length, glock->proc_id, glock->client_id);
error:
p9_free_req(clnt, req);
return err;
}
EXPORT_SYMBOL(p9_client_getlock_dotl);