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path: root/source4/ntvfs/posix/pvfs_lock.c
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Diffstat (limited to 'source4/ntvfs/posix/pvfs_lock.c')
-rw-r--r--source4/ntvfs/posix/pvfs_lock.c186
1 files changed, 182 insertions, 4 deletions
diff --git a/source4/ntvfs/posix/pvfs_lock.c b/source4/ntvfs/posix/pvfs_lock.c
index d7aca9df8b..548c5bd82c 100644
--- a/source4/ntvfs/posix/pvfs_lock.c
+++ b/source4/ntvfs/posix/pvfs_lock.c
@@ -44,6 +44,153 @@ NTSTATUS pvfs_check_lock(struct pvfs_state *pvfs,
offset, count, rw);
}
+/* this state structure holds information about a lock we are waiting on */
+struct pending_state {
+ struct pvfs_state *pvfs;
+ union smb_lock *lck;
+ struct pvfs_file *f;
+ struct smbsrv_request *req;
+ int pending_lock;
+ void *wait_handle;
+ time_t end_time;
+};
+
+
+/*
+ a secondary attempt to setup a lock has failed - back out
+ the locks we did get and send an error
+*/
+static void pvfs_lock_async_failed(struct pvfs_state *pvfs,
+ struct smbsrv_request *req,
+ struct pvfs_file *f,
+ struct smb_lock_entry *locks,
+ int i,
+ NTSTATUS status)
+{
+ /* undo the locks we just did */
+ for (i=i-1;i>=0;i--) {
+ brl_unlock(pvfs->brl_context,
+ &f->locking_key,
+ locks[i].pid,
+ f->fnum,
+ locks[i].offset,
+ locks[i].count);
+ }
+ req->async.status = status;
+ req->async.send_fn(req);
+}
+
+
+/*
+ called when we receive a pending lock notification. It means that
+ either our lock timed out or somoene else has unlocked a overlapping
+ range, so we should try the lock again. Note that on timeout we
+ do retry the lock, giving it a last chance.
+*/
+static void pvfs_pending_lock_continue(void *private, BOOL timed_out)
+{
+ struct pending_state *pending = private;
+ struct pvfs_state *pvfs = pending->pvfs;
+ struct pvfs_file *f = pending->f;
+ struct smbsrv_request *req = pending->req;
+ union smb_lock *lck = pending->lck;
+ struct smb_lock_entry *locks;
+ enum brl_type rw;
+ NTSTATUS status;
+ int i;
+
+ locks = lck->lockx.in.locks + lck->lockx.in.ulock_cnt;
+
+ if (lck->lockx.in.mode & LOCKING_ANDX_SHARED_LOCK) {
+ rw = READ_LOCK;
+ } else {
+ rw = WRITE_LOCK;
+ }
+
+ status = brl_lock(pvfs->brl_context,
+ &f->locking_key,
+ req->smbpid,
+ f->fnum,
+ locks[pending->pending_lock].offset,
+ locks[pending->pending_lock].count,
+ rw, NULL);
+
+ /* if we have failed and timed out, or succeeded, then we
+ don't need the pending lock any more */
+ if (NT_STATUS_IS_OK(status) || timed_out) {
+ NTSTATUS status2;
+ status2 = brl_remove_pending(pvfs->brl_context, &f->locking_key, pending);
+ if (!NT_STATUS_IS_OK(status2)) {
+ DEBUG(0,("pvfs_lock: failed to remove pending lock - %s\n", nt_errstr(status2)));
+ }
+ talloc_free(pending->wait_handle);
+ }
+
+ if (!NT_STATUS_IS_OK(status)) {
+ if (timed_out) {
+ /* no more chances */
+ pvfs_lock_async_failed(pvfs, req, f, locks, pending->pending_lock, status);
+ }
+ /* we can try again */
+ return;
+ }
+
+ /* if we haven't timed out yet, then we can do more pending locks */
+ if (timed_out) {
+ pending = NULL;
+ } else {
+ if (rw == READ_LOCK) {
+ rw = PENDING_READ_LOCK;
+ } else {
+ rw = PENDING_WRITE_LOCK;
+ }
+ }
+
+ /* we've now got the pending lock. try and get the rest, which might
+ lead to more pending locks */
+ for (i=pending->pending_lock;i<lck->lockx.in.lock_cnt;i++) {
+ if (pending) {
+ pending->pending_lock = i;
+ }
+
+ status = brl_lock(pvfs->brl_context,
+ &f->locking_key,
+ req->smbpid,
+ f->fnum,
+ locks[i].offset,
+ locks[i].count,
+ rw, pending);
+ if (!NT_STATUS_IS_OK(status)) {
+ if (pending) {
+ /* a timed lock failed - setup a wait message to handle
+ the pending lock notification or a timeout */
+ pending->wait_handle = pvfs_wait_message(pvfs, req, MSG_BRL_RETRY,
+ pending->end_time,
+ pvfs_pending_lock_continue,
+ pending);
+ if (pending->wait_handle == NULL) {
+ pvfs_lock_async_failed(pvfs, req, f, locks, i, NT_STATUS_NO_MEMORY);
+ }
+ return;
+ }
+ pvfs_lock_async_failed(pvfs, req, f, locks, i, status);
+ return;
+ }
+ }
+
+ brl_unlock(pvfs->brl_context,
+ &f->locking_key,
+ req->smbpid,
+ f->fnum,
+ lck->lock.in.offset,
+ lck->lock.in.count);
+
+ /* we've managed to get all the locks. Tell the client */
+ req->async.status = NT_STATUS_OK;
+ req->async.send_fn(req);
+}
+
+
/*
lock or unlock a byte range
*/
@@ -55,6 +202,7 @@ NTSTATUS pvfs_lock(struct ntvfs_module_context *ntvfs,
struct smb_lock_entry *locks;
int i;
enum brl_type rw;
+ struct pending_state *pending = NULL;
f = pvfs_find_fd(pvfs, req, lck->generic.in.fnum);
if (!f) {
@@ -69,7 +217,7 @@ NTSTATUS pvfs_lock(struct ntvfs_module_context *ntvfs,
f->fnum,
lck->lock.in.offset,
lck->lock.in.count,
- WRITE_LOCK);
+ WRITE_LOCK, NULL);
case RAW_LOCK_UNLOCK:
return brl_unlock(pvfs->brl_context,
@@ -88,11 +236,25 @@ NTSTATUS pvfs_lock(struct ntvfs_module_context *ntvfs,
}
/* now the lockingX case, most common and also most complex */
+ if (lck->lockx.in.timeout != 0) {
+ pending = talloc_p(req, struct pending_state);
+ if (pending == NULL) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ pending->pvfs = pvfs;
+ pending->lck = lck;
+ pending->f = f;
+ pending->req = req;
+
+ /* round up to the nearest second */
+ pending->end_time = time(NULL) + ((lck->lockx.in.timeout+999)/1000);
+ }
if (lck->lockx.in.mode & LOCKING_ANDX_SHARED_LOCK) {
- rw = READ_LOCK;
+ rw = pending? PENDING_READ_LOCK : READ_LOCK;
} else {
- rw = WRITE_LOCK;
+ rw = pending? PENDING_WRITE_LOCK : WRITE_LOCK;
}
if (lck->lockx.in.mode &
@@ -125,14 +287,30 @@ NTSTATUS pvfs_lock(struct ntvfs_module_context *ntvfs,
for (i=0;i<lck->lockx.in.lock_cnt;i++) {
NTSTATUS status;
+ if (pending) {
+ pending->pending_lock = i;
+ }
+
status = brl_lock(pvfs->brl_context,
&f->locking_key,
locks[i].pid,
f->fnum,
locks[i].offset,
locks[i].count,
- rw);
+ rw, pending);
if (!NT_STATUS_IS_OK(status)) {
+ if (pending) {
+ /* a timed lock failed - setup a wait message to handle
+ the pending lock notification or a timeout */
+ pending->wait_handle = pvfs_wait_message(pvfs, req, MSG_BRL_RETRY,
+ pending->end_time,
+ pvfs_pending_lock_continue,
+ pending);
+ if (pending->wait_handle == NULL) {
+ return NT_STATUS_NO_MEMORY;
+ }
+ return NT_STATUS_OK;
+ }
/* undo the locks we just did */
for (i=i-1;i>=0;i--) {
brl_unlock(pvfs->brl_context,
generated by cgit (git 2.34.1) at 2024-07-03 03:16:24 +0000