Commit 1d769cd1 authored by M. Mohan Kumar's avatar M. Mohan Kumar Committed by Eric Van Hensbergen
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9p: Implement TGETLOCK



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: default avatarM. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
parent a099027c
......@@ -211,6 +211,51 @@ out:
return res;
}
static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
{
struct p9_getlock glock;
struct p9_fid *fid;
int res = 0;
fid = filp->private_data;
BUG_ON(fid == NULL);
posix_test_lock(filp, fl);
/*
* if we have a conflicting lock locally, no need to validate
* with server
*/
if (fl->fl_type != F_UNLCK)
return res;
/* convert posix lock to p9 tgetlock args */
memset(&glock, 0, sizeof(glock));
glock.type = fl->fl_type;
glock.start = fl->fl_start;
if (fl->fl_end == OFFSET_MAX)
glock.length = 0;
else
glock.length = fl->fl_end - fl->fl_start + 1;
glock.proc_id = fl->fl_pid;
glock.client_id = utsname()->nodename;
res = p9_client_getlock_dotl(fid, &glock);
if (res < 0)
return res;
if (glock.type != F_UNLCK) {
fl->fl_type = glock.type;
fl->fl_start = glock.start;
if (glock.length == 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = glock.start + glock.length - 1;
fl->fl_pid = glock.proc_id;
} else
fl->fl_type = F_UNLCK;
return res;
}
/**
* v9fs_file_lock_dotl - lock a file (or directory)
* @filp: file to be locked
......@@ -238,6 +283,8 @@ static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
if (IS_SETLK(cmd) || IS_SETLKW(cmd))
ret = v9fs_file_do_lock(filp, cmd, fl);
else if (IS_GETLK(cmd))
ret = v9fs_file_getlock(filp, fl);
else
ret = -EINVAL;
out_err:
......
......@@ -167,6 +167,8 @@ enum p9_msg_t {
P9_RFSYNC,
P9_TLOCK = 52,
P9_RLOCK,
P9_TGETLOCK = 54,
P9_RGETLOCK,
P9_TLINK = 70,
P9_RLINK,
P9_TMKDIR = 72,
......@@ -492,6 +494,22 @@ struct p9_flock {
char *client_id;
};
/* struct p9_getlock: getlock structure
* @type - type of lock
* @start - starting offset of the lock
* @length - number of bytes
* @proc_id - process id which wants to take lock
* @client_id - client id
*/
struct p9_getlock {
u8 type;
u64 start;
u64 length;
u32 proc_id;
char *client_id;
};
/* Structures for Protocol Operations */
struct p9_tstatfs {
u32 fid;
......
......@@ -250,6 +250,7 @@ int p9_client_mknod_dotl(struct p9_fid *oldfid, char *name, int mode,
int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
gid_t gid, struct p9_qid *);
int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
void p9_client_cb(struct p9_client *c, struct p9_req_t *req);
......
......@@ -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);
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