From 1d769cd192fc8c4097b1e2cd41fdee6ba3d1b2af Mon Sep 17 00:00:00 2001 From: "M. Mohan Kumar" Date: Mon, 27 Sep 2010 12:22:13 +0530 Subject: [PATCH] 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 Signed-off-by: Aneesh Kumar K.V Signed-off-by: Venkateswararao Jujjuri Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_file.c | 47 +++++++++++++++++++++++++++++++++++++++++ include/net/9p/9p.h | 18 ++++++++++++++++ include/net/9p/client.h | 1 + net/9p/client.c | 34 +++++++++++++++++++++++++++++ 4 files changed, 100 insertions(+) diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 6f77abd23184..3a4352f23a98 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -211,6 +211,51 @@ static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl) 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: diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h index 1859a2560cc5..6367a71d84fc 100644 --- a/include/net/9p/9p.h +++ b/include/net/9p/9p.h @@ -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; diff --git a/include/net/9p/client.h b/include/net/9p/client.h index d7dcb142e3bb..127c9f2a9cb8 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -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); diff --git a/net/9p/client.c b/net/9p/client.c index fbd2b195801c..fc1b0579016a 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -1836,3 +1836,37 @@ int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status) } 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);