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: 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>
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 6f77abd..3a4352f 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -211,6 +211,51 @@
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 @@
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:
diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index 1859a25..6367a71 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -167,6 +167,8 @@
P9_RFSYNC,
P9_TLOCK = 52,
P9_RLOCK,
+ P9_TGETLOCK = 54,
+ P9_RGETLOCK,
P9_TLINK = 70,
P9_RLINK,
P9_TMKDIR = 72,
@@ -492,6 +494,22 @@
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;
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index d7dcb14..127c9f2 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -250,6 +250,7 @@
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);
diff --git a/net/9p/client.c b/net/9p/client.c
index fbd2b19..fc1b057 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1836,3 +1836,37 @@
}
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);