From patchwork Wed Sep 8 13:23:39 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mohan Kumar M X-Patchwork-Id: 64129 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 62E84B6EF7 for ; Wed, 8 Sep 2010 23:26:15 +1000 (EST) Received: from localhost ([127.0.0.1]:39877 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OtKer-00083Q-G3 for incoming@patchwork.ozlabs.org; Wed, 08 Sep 2010 09:25:49 -0400 Received: from [140.186.70.92] (port=45176 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OtKd2-0007A5-Jw for qemu-devel@nongnu.org; Wed, 08 Sep 2010 09:24:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OtKcu-0004QC-15 for qemu-devel@nongnu.org; Wed, 08 Sep 2010 09:23:56 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:50463) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OtKct-0004OU-Fs for qemu-devel@nongnu.org; Wed, 08 Sep 2010 09:23:48 -0400 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [202.81.31.245]) by e23smtp05.au.ibm.com (8.14.4/8.13.1) with ESMTP id o88DJ8b1016382 for ; Wed, 8 Sep 2010 23:19:08 +1000 Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o88DNfwG688164 for ; Wed, 8 Sep 2010 23:23:41 +1000 Received: from d23av03.au.ibm.com (loopback [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o88DNfXA007725 for ; Wed, 8 Sep 2010 23:23:41 +1000 Received: from localhost.localdomain ([9.77.192.56]) by d23av03.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id o88DNecb007715 for ; Wed, 8 Sep 2010 23:23:40 +1000 From: "M. Mohan Kumar" To: qemu-devel@nongnu.org Date: Wed, 8 Sep 2010 18:53:39 +0530 Message-Id: <1283952219-8700-1-git-send-email-mohan@in.ibm.com> X-Mailer: git-send-email 1.7.0.4 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) Subject: [Qemu-devel] [PATCH 1/2] qemu-virto9p: Implement TLOCK X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org 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(1) - Blocked lock request, if there is a conflicting lock exists, wait for that lock to be released. P9_LOCK_FLAGS_RECLAIM(2) - 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 --- hw/virtio-9p-debug.c | 14 ++++++++++++++ hw/virtio-9p.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ hw/virtio-9p.h | 30 ++++++++++++++++++++++++++++++ 3 files changed, 94 insertions(+), 0 deletions(-) diff --git a/hw/virtio-9p-debug.c b/hw/virtio-9p-debug.c index 6f6a0ec..045774f 100644 --- a/hw/virtio-9p-debug.c +++ b/hw/virtio-9p-debug.c @@ -588,6 +588,20 @@ void pprint_pdu(V9fsPDU *pdu) case P9_RXATTRCREATE: fprintf(llogfile, "RXATTRCREATE: ("); break; + case P9_TLOCK: + fprintf(llogfile, "TLOCK: ("); + pprint_int32(pdu, 0, &offset, "fid"); + pprint_int8(pdu, 0, &offset, ", type"); + pprint_int32(pdu, 0, &offset, ", flags"); + pprint_int64(pdu, 0, &offset, ", start"); + pprint_int64(pdu, 0, &offset, ", length"); + pprint_int32(pdu, 0, &offset, ", proc_id"); + pprint_str(pdu, 0, &offset, ", client_id"); + break; + case P9_RLOCK: + fprintf(llogfile, "RLOCK: ("); + pprint_int8(pdu, 0, &offset, "status"); + break; default: fprintf(llogfile, "unknown(%d): (", pdu->id); break; diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c index 32fa3bc..b3d55f1 100644 --- a/hw/virtio-9p.c +++ b/hw/virtio-9p.c @@ -3150,6 +3150,55 @@ out: qemu_free(vs); } +/* + * Implement posix byte range locking code + * Server side handling of locking code is very simple, because 9p server in QEMU + * can handle only one client. And most of the lock handling (like conflict, + * merging) etc is done by the VFS layer itself, so no need to do any thing in + * qemu 9p server side lock code path. + * So when a TLOCK request comes, always return success + */ + +static void v9fs_lock(V9fsState *s, V9fsPDU *pdu) +{ + int32_t fid, err = 0; + V9fsLockState *vs; + + vs = qemu_mallocz(sizeof(*vs)); + vs->pdu = pdu; + vs->offset = 7; + + vs->flock = qemu_malloc(sizeof(*vs->flock)); + pdu_unmarshal(vs->pdu, vs->offset, "dbdqqds", &fid, &vs->flock->type, + &vs->flock->flags, &vs->flock->start, &vs->flock->length, + &vs->flock->proc_id, &vs->flock->client_id); + + vs->status = P9_LOCK_ERROR; + + /* We support only block flag now (that too ignored currently) */ + if (vs->flock->flags & ~P9_LOCK_FLAGS_BLOCK) { + err = -EINVAL; + goto out; + } + vs->fidp = lookup_fid(s, fid); + if (vs->fidp == NULL) { + err = -ENOENT; + goto out; + } + + err = v9fs_do_fstat(s, vs->fidp->fs.fd, &vs->stbuf); + if (err < 0) { + err = -errno; + goto out; + } + vs->status = P9_LOCK_SUCCESS; +out: + vs->offset += pdu_marshal(vs->pdu, vs->offset, "b", vs->status); + complete_pdu(s, vs->pdu, err); + qemu_free(vs->flock); + qemu_free(vs); +} + static void v9fs_mkdir_post_lstat(V9fsState *s, V9fsMkState *vs, int err) { if (err == -1) { @@ -3412,6 +3461,7 @@ static pdu_handler_t *pdu_handlers[] = { [P9_TXATTRCREATE] = v9fs_xattrcreate, [P9_TMKNOD] = v9fs_mknod, [P9_TRENAME] = v9fs_rename, + [P9_TLOCK] = v9fs_lock, [P9_TMKDIR] = v9fs_mkdir, [P9_TVERSION] = v9fs_version, [P9_TLOPEN] = v9fs_open, diff --git a/hw/virtio-9p.h b/hw/virtio-9p.h index 0816ad6..4555f39 100644 --- a/hw/virtio-9p.h +++ b/hw/virtio-9p.h @@ -37,6 +37,8 @@ enum { P9_RXATTRCREATE, P9_TREADDIR = 40, P9_RREADDIR, + P9_TLOCK = 52, + P9_RLOCK, P9_TLINK = 70, P9_RLINK, P9_TMKDIR = 72, @@ -434,6 +436,34 @@ typedef struct V9fsXattrState void *value; } V9fsXattrState; +#define P9_LOCK_SUCCESS 0 +#define P9_LOCK_BLOCKED 1 +#define P9_LOCK_ERROR 2 +#define P9_LOCK_GRACE 3 + +#define P9_LOCK_FLAGS_BLOCK 1 +#define P9_LOCK_FLAGS_RECLAIM 2 + +typedef struct V9fsFlock +{ + uint8_t type; + uint32_t flags; + uint64_t start; /* absolute offset */ + uint64_t length; + uint32_t proc_id; + V9fsString client_id; +} V9fsFlock; + +typedef struct V9fsLockState +{ + V9fsPDU *pdu; + size_t offset; + int8_t status; + struct stat stbuf; + V9fsFidState *fidp; + V9fsFlock *flock; +} V9fsLockState; + extern size_t pdu_packunpack(void *addr, struct iovec *sg, int sg_count, size_t offset, size_t size, int pack);