[virto-9p] Implement TLOCK
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 <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>
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 @@
P9_RXATTRCREATE,
P9_TREADDIR = 40,
P9_RREADDIR,
+ P9_TLOCK = 52,
+ P9_RLOCK,
P9_TLINK = 70,
P9_RLINK,
P9_TMKDIR = 72,
@@ -434,6 +436,34 @@
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);
