vfs_streams_xattr: add pread_send/recv and pwrite_send/recv

This is needed to support copy-chunk of streams. vfs_default issues
calls to async pread and pwrite (send/recv versions) since commit
60e45a2d25401eaf9a15a86d19114670ccfde259.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=12787

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: David Disseldorp <ddiss@samba.org>

diff --git a/source3/modules/vfs_streams_xattr.c b/source3/modules/vfs_streams_xattr.c
index 2943e521264cc1c01eabd1fc324e49f371c278f9..f481f27657f886e48e40bc2bcc0279c903eff526 100644 (file)
--- a/source3/modules/vfs_streams_xattr.c
+++ b/source3/modules/vfs_streams_xattr.c
@@ -25,6 +25,7 @@
 #include "smbd/smbd.h"
 #include "system/filesys.h"
 #include "../lib/crypto/md5.h"
+#include "lib/util/tevent_unix.h"
 
 #undef DBGC_CLASS
 #define DBGC_CLASS DBGC_VFS
@@ -1048,6 +1049,166 @@ static ssize_t streams_xattr_pread(vfs_handle_struct *handle,
         return overlap;
 }
 
+struct streams_xattr_pread_state {
+       ssize_t nread;
+       struct vfs_aio_state vfs_aio_state;
+};
+
+static void streams_xattr_pread_done(struct tevent_req *subreq);
+
+static struct tevent_req *streams_xattr_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 = NULL;
+       struct tevent_req *subreq = NULL;
+       struct streams_xattr_pread_state *state = NULL;
+       struct stream_io *sio =
+               (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
+
+       req = tevent_req_create(mem_ctx, &state,
+                               struct streams_xattr_pread_state);
+       if (req == NULL) {
+               return NULL;
+       }
+
+       if (sio == NULL) {
+               subreq = SMB_VFS_NEXT_PREAD_SEND(state, ev, handle, fsp,
+                                                data, n, offset);
+               if (tevent_req_nomem(req, subreq)) {
+                       return tevent_req_post(req, ev);
+               }
+               tevent_req_set_callback(subreq, streams_xattr_pread_done, req);
+               return req;
+       }
+
+       state->nread = SMB_VFS_PREAD(fsp, data, n, offset);
+       if (state->nread != n) {
+               if (state->nread != -1) {
+                       errno = EIO;
+               }
+               tevent_req_error(req, errno);
+               return tevent_req_post(req, ev);
+       }
+
+       tevent_req_done(req);
+       return tevent_req_post(req, ev);
+}
+
+static void streams_xattr_pread_done(struct tevent_req *subreq)
+{
+       struct tevent_req *req = tevent_req_callback_data(
+               subreq, struct tevent_req);
+       struct streams_xattr_pread_state *state = tevent_req_data(
+               req, struct streams_xattr_pread_state);
+
+       state->nread = SMB_VFS_PREAD_RECV(subreq, &state->vfs_aio_state);
+       TALLOC_FREE(subreq);
+
+       if (tevent_req_error(req, state->vfs_aio_state.error)) {
+               return;
+       }
+       tevent_req_done(req);
+}
+
+static ssize_t streams_xattr_pread_recv(struct tevent_req *req,
+                                       struct vfs_aio_state *vfs_aio_state)
+{
+       struct streams_xattr_pread_state *state = tevent_req_data(
+               req, struct streams_xattr_pread_state);
+
+       if (tevent_req_is_unix_error(req, &vfs_aio_state->error)) {
+               return -1;
+       }
+
+       *vfs_aio_state = state->vfs_aio_state;
+       return state->nread;
+}
+
+struct streams_xattr_pwrite_state {
+       ssize_t nwritten;
+       struct vfs_aio_state vfs_aio_state;
+};
+
+static void streams_xattr_pwrite_done(struct tevent_req *subreq);
+
+static struct tevent_req *streams_xattr_pwrite_send(
+       struct vfs_handle_struct *handle,
+       TALLOC_CTX *mem_ctx,
+       struct tevent_context *ev,
+       struct files_struct *fsp,
+       const void *data,
+       size_t n, off_t offset)
+{
+       struct tevent_req *req = NULL;
+       struct tevent_req *subreq = NULL;
+       struct streams_xattr_pwrite_state *state = NULL;
+       struct stream_io *sio =
+               (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
+
+       req = tevent_req_create(mem_ctx, &state,
+                               struct streams_xattr_pwrite_state);
+       if (req == NULL) {
+               return NULL;
+       }
+
+       if (sio == NULL) {
+               subreq = SMB_VFS_NEXT_PWRITE_SEND(state, ev, handle, fsp,
+                                                 data, n, offset);
+               if (tevent_req_nomem(req, subreq)) {
+                       return tevent_req_post(req, ev);
+               }
+               tevent_req_set_callback(subreq, streams_xattr_pwrite_done, req);
+               return req;
+       }
+
+       state->nwritten = SMB_VFS_PWRITE(fsp, data, n, offset);
+       if (state->nwritten != n) {
+               if (state->nwritten != -1) {
+                       errno = EIO;
+               }
+               tevent_req_error(req, errno);
+               return tevent_req_post(req, ev);
+       }
+
+       tevent_req_done(req);
+       return tevent_req_post(req, ev);
+}
+
+static void streams_xattr_pwrite_done(struct tevent_req *subreq)
+{
+       struct tevent_req *req = tevent_req_callback_data(
+               subreq, struct tevent_req);
+       struct streams_xattr_pwrite_state *state = tevent_req_data(
+               req, struct streams_xattr_pwrite_state);
+
+       state->nwritten = SMB_VFS_PWRITE_RECV(subreq, &state->vfs_aio_state);
+       TALLOC_FREE(subreq);
+
+       if (tevent_req_error(req, state->vfs_aio_state.error)) {
+               return;
+       }
+       tevent_req_done(req);
+}
+
+static ssize_t streams_xattr_pwrite_recv(struct tevent_req *req,
+                                        struct vfs_aio_state *vfs_aio_state)
+{
+       struct streams_xattr_pwrite_state *state = tevent_req_data(
+               req, struct streams_xattr_pwrite_state);
+
+       if (tevent_req_is_unix_error(req, &vfs_aio_state->error)) {
+               return -1;
+       }
+
+       *vfs_aio_state = state->vfs_aio_state;
+       return state->nwritten;
+}
+
 static int streams_xattr_ftruncate(struct vfs_handle_struct *handle,
                                        struct files_struct *fsp,
                                        off_t offset)
@@ -1151,6 +1312,10 @@ static struct vfs_fn_pointers vfs_streams_xattr_fns = {
        .lstat_fn = streams_xattr_lstat,
        .pread_fn = streams_xattr_pread,
        .pwrite_fn = streams_xattr_pwrite,
+       .pread_send_fn = streams_xattr_pread_send,
+       .pread_recv_fn = streams_xattr_pread_recv,
+       .pwrite_send_fn = streams_xattr_pwrite_send,
+       .pwrite_recv_fn = streams_xattr_pwrite_recv,
        .unlink_fn = streams_xattr_unlink,
        .rename_fn = streams_xattr_rename,
        .ftruncate_fn = streams_xattr_ftruncate,