s3-vfs: async pread

Signed-off-by: Jeremy Allison <jra@samba.org>

4 files changed, 131 insertions, 0 deletions

diff --git a/source3/include/vfs.h b/source3/include/vfs.h
index 2a466de0b4..5355d7a836 100644
--- a/source3/include/vfs.h
+++ b/source3/include/vfs.h
@@ -515,6 +515,13 @@ struct vfs_fn_pointers {
 	int (*close_fn)(struct vfs_handle_struct *handle, struct files_struct *fsp);
 	ssize_t (*read_fn)(struct vfs_handle_struct *handle, struct files_struct *fsp, void *data, size_t n);
 	ssize_t (*pread_fn)(struct vfs_handle_struct *handle, struct files_struct *fsp, void *data, size_t n, off_t offset);
+	struct tevent_req *(*pread_send_fn)(struct vfs_handle_struct *handle,
+					    TALLOC_CTX *mem_ctx,
+					    struct tevent_context *ev,
+					    struct files_struct *fsp,
+					    void *data,
+					    size_t n, off_t offset);
+	ssize_t (*pread_recv_fn)(struct tevent_req *req, int *err);
 	ssize_t (*write_fn)(struct vfs_handle_struct *handle, struct files_struct *fsp, const void *data, size_t n);
 	ssize_t (*pwrite_fn)(struct vfs_handle_struct *handle, struct files_struct *fsp, const void *data, size_t n, off_t offset);
 	struct tevent_req *(*pwrite_send_fn)(struct vfs_handle_struct *handle,
@@ -885,6 +892,14 @@ ssize_t smb_vfs_call_read(struct vfs_handle_struct *handle,
 ssize_t smb_vfs_call_pread(struct vfs_handle_struct *handle,
 			   struct files_struct *fsp, void *data, size_t n,
 			   off_t offset);
+struct tevent_req *smb_vfs_call_pread_send(struct vfs_handle_struct *handle,
+					   TALLOC_CTX *mem_ctx,
+					   struct tevent_context *ev,
+					   struct files_struct *fsp,
+					   void *data,
+					   size_t n, off_t offset);
+ssize_t SMB_VFS_PREAD_RECV(struct tevent_req *req, int *perrno);
+
 ssize_t smb_vfs_call_write(struct vfs_handle_struct *handle,
 			   struct files_struct *fsp, const void *data,
 			   size_t n);
diff --git a/source3/include/vfs_macros.h b/source3/include/vfs_macros.h
index 24add0b926..80b375e6e0 100644
--- a/source3/include/vfs_macros.h
+++ b/source3/include/vfs_macros.h
@@ -158,6 +158,13 @@
 #define SMB_VFS_NEXT_PREAD(handle, fsp, data, n, off) \
 	smb_vfs_call_pread((handle)->next, (fsp), (data), (n), (off))
 
+#define SMB_VFS_PREAD_SEND(mem_ctx, ev, fsp, data, n, off) \
+	smb_vfs_call_pread_send((fsp)->conn->vfs_handles, (mem_ctx), (ev), \
+				(fsp), (data), (n), (off))
+#define SMB_VFS_NEXT_PREAD_SEND(mem_ctx, ev, handle, fsp, data, n, off)	\
+	smb_vfs_call_pread_send((handle)->next, (mem_ctx), (ev), (fsp), \
+				(data), (n), (off))
+
 #define SMB_VFS_WRITE(fsp, data, n) \
 	smb_vfs_call_write((fsp)->conn->vfs_handles, (fsp), (data), (n))
 #define SMB_VFS_NEXT_WRITE(handle, fsp, data, n) \
diff --git a/source3/modules/vfs_default.c b/source3/modules/vfs_default.c
index 2235ef98a9..aa38a50b80 100644
--- a/source3/modules/vfs_default.c
+++ b/source3/modules/vfs_default.c
@@ -580,6 +580,49 @@ static ssize_t vfswrap_pread(vfs_handle_struct *handle, files_struct *fsp, void
 	return result;
 }
 
+struct vfswrap_pread_state {
+	ssize_t ret;
+};
+
+static struct tevent_req *vfswrap_pread_send(struct vfs_handle_struct *handle,
+					     TALLOC_CTX *mem_ctx,
+					     struct tevent_context *ev,
+					     struct files_struct *fsp,
+					     void *data,
+					     size_t n, off_t offset)
+{
+	struct tevent_req *req;
+	struct vfswrap_pread_state *state;
+	int saved_errno;
+
+	req = tevent_req_create(req, &state, struct vfswrap_pread_state);
+	if (req == NULL) {
+		return NULL;
+	}
+	START_PROFILE_BYTES(syscall_pread, n);
+	state->ret = sys_pread(fsp->fh->fd, data, n, offset);
+	saved_errno = errno;
+	END_PROFILE(syscall_pread);
+
+	if (state->ret == -1) {
+		tevent_req_error(req, saved_errno);
+		return tevent_req_post(req, ev);
+	}
+	tevent_req_done(req);
+	return tevent_req_post(req, ev);
+}
+
+static ssize_t vfswrap_pread_recv(struct tevent_req *req, int *err)
+{
+	struct vfswrap_pread_state *state = tevent_req_data(
+		req, struct vfswrap_pread_state);
+
+	if (tevent_req_is_unix_error(req, err)) {
+		return -1;
+	}
+	return state->ret;
+}
+
 static ssize_t vfswrap_write(vfs_handle_struct *handle, files_struct *fsp, const void *data, size_t n)
 {
 	ssize_t result;
@@ -2255,6 +2298,8 @@ static struct vfs_fn_pointers vfs_default_fns = {
 	.close_fn = vfswrap_close,
 	.read_fn = vfswrap_read,
 	.pread_fn = vfswrap_pread,
+	.pread_send_fn = vfswrap_pread_send,
+	.pread_recv_fn = vfswrap_pread_recv,
 	.write_fn = vfswrap_write,
 	.pwrite_fn = vfswrap_pwrite,
 	.pwrite_send_fn = vfswrap_pwrite_send,
diff --git a/source3/smbd/vfs.c b/source3/smbd/vfs.c
index 9b666e0bf6..0414332073 100644
--- a/source3/smbd/vfs.c
+++ b/source3/smbd/vfs.c
@@ -1541,6 +1541,70 @@ ssize_t smb_vfs_call_pread(struct vfs_handle_struct *handle,
 	return handle->fns->pread_fn(handle, fsp, data, n, offset);
 }
 
+struct smb_vfs_call_pread_state {
+	ssize_t (*recv_fn)(struct tevent_req *req, int *err);
+	ssize_t retval;
+};
+
+static void smb_vfs_call_pread_done(struct tevent_req *subreq);
+
+struct tevent_req *smb_vfs_call_pread_send(struct vfs_handle_struct *handle,
+					   TALLOC_CTX *mem_ctx,
+					   struct tevent_context *ev,
+					   struct files_struct *fsp,
+					   void *data,
+					   size_t n, off_t offset)
+{
+	struct tevent_req *req, *subreq;
+	struct smb_vfs_call_pread_state *state;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct smb_vfs_call_pread_state);
+	if (req == NULL) {
+		return NULL;
+	}
+	VFS_FIND(pread_send);
+	state->recv_fn = handle->fns->pread_recv_fn;
+
+	subreq = handle->fns->pread_send_fn(handle, state, ev, fsp, data, n,
+					    offset);
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
+	}
+	tevent_req_set_callback(subreq, smb_vfs_call_pread_done, req);
+	return req;
+}
+
+static void smb_vfs_call_pread_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct smb_vfs_call_pread_state *state = tevent_req_data(
+		req, struct smb_vfs_call_pread_state);
+	int err;
+
+	state->retval = state->recv_fn(subreq, &err);
+	TALLOC_FREE(subreq);
+	if (state->retval == -1) {
+		tevent_req_error(req, err);
+		return;
+	}
+	tevent_req_done(req);
+}
+
+ssize_t SMB_VFS_PREAD_RECV(struct tevent_req *req, int *perrno)
+{
+	struct smb_vfs_call_pread_state *state = tevent_req_data(
+		req, struct smb_vfs_call_pread_state);
+	int err;
+
+	if (tevent_req_is_unix_error(req, &err)) {
+		*perrno = err;
+		return -1;
+	}
+	return state->retval;
+}
+
 ssize_t smb_vfs_call_write(struct vfs_handle_struct *handle,
 			   struct files_struct *fsp, const void *data,
 			   size_t n)