1 files changed, 84 insertions, 46 deletions

diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index 01feebec29ea..12eaa8ddc248 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -83,17 +83,16 @@ static void nvmet_file_init_bvec(struct bio_vec *bv, struct sg_page_iter *iter)
 }
 
 static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
-		unsigned long nr_segs, size_t count)
+		unsigned long nr_segs, size_t count, int ki_flags)
 {
 	struct kiocb *iocb = &req->f.iocb;
 	ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
 	struct iov_iter iter;
-	int ki_flags = 0, rw;
-	ssize_t ret;
+	int rw;
 
 	if (req->cmd->rw.opcode == nvme_cmd_write) {
 		if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
-			ki_flags = IOCB_DSYNC;
+			ki_flags |= IOCB_DSYNC;
 		call_iter = req->ns->file->f_op->write_iter;
 		rw = WRITE;
 	} else {
@@ -107,12 +106,7 @@ static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
 	iocb->ki_filp = req->ns->file;
 	iocb->ki_flags = ki_flags | iocb_flags(req->ns->file);
 
-	ret = call_iter(iocb, &iter);
-
-	if (ret != -EIOCBQUEUED && iocb->ki_complete)
-		iocb->ki_complete(iocb, ret, 0);
-
-	return ret;
+	return call_iter(iocb, &iter);
 }
 
 static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2)
@@ -130,7 +124,7 @@ static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2)
 			NVME_SC_INTERNAL | NVME_SC_DNR : 0);
 }
 
-static void nvmet_file_execute_rw(struct nvmet_req *req)
+static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags)
 {
 	ssize_t nr_bvec = DIV_ROUND_UP(req->data_len, PAGE_SIZE);
 	struct sg_page_iter sg_pg_iter;
@@ -140,30 +134,14 @@ static void nvmet_file_execute_rw(struct nvmet_req *req)
 	ssize_t ret = 0;
 	loff_t pos;
 
-	if (!req->sg_cnt || !nr_bvec) {
-		nvmet_req_complete(req, 0);
-		return;
-	}
+
+	if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC)
+		is_sync = true;
 
 	pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
 	if (unlikely(pos + req->data_len > req->ns->size)) {
 		nvmet_req_complete(req, NVME_SC_LBA_RANGE | NVME_SC_DNR);
-		return;
-	}
-
-	if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
-		req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
-				GFP_KERNEL);
-	else
-		req->f.bvec = req->inline_bvec;
-
-	req->f.mpool_alloc = false;
-	if (unlikely(!req->f.bvec)) {
-		/* fallback under memory pressure */
-		req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
-		req->f.mpool_alloc = true;
-		if (nr_bvec > NVMET_MAX_MPOOL_BVEC)
-			is_sync = true;
+		return true;
 	}
 
 	memset(&req->f.iocb, 0, sizeof(struct kiocb));
@@ -177,9 +155,10 @@ static void nvmet_file_execute_rw(struct nvmet_req *req)
 
 		if (unlikely(is_sync) &&
 		    (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) {
-			ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len);
+			ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0);
 			if (ret < 0)
-				goto out;
+				goto complete;
+
 			pos += len;
 			bv_cnt = 0;
 			len = 0;
@@ -187,30 +166,92 @@ static void nvmet_file_execute_rw(struct nvmet_req *req)
 		nr_bvec--;
 	}
 
-	if (WARN_ON_ONCE(total_len != req->data_len))
+	if (WARN_ON_ONCE(total_len != req->data_len)) {
 		ret = -EIO;
-out:
-	if (unlikely(is_sync || ret)) {
-		nvmet_file_io_done(&req->f.iocb, ret < 0 ? ret : total_len, 0);
-		return;
+		goto complete;
+	}
+
+	if (unlikely(is_sync)) {
+		ret = total_len;
+		goto complete;
 	}
-	req->f.iocb.ki_complete = nvmet_file_io_done;
-	nvmet_file_submit_bvec(req, pos, bv_cnt, total_len);
+
+	/*
+	 * A NULL ki_complete ask for synchronous execution, which we want
+	 * for the IOCB_NOWAIT case.
+	 */
+	if (!(ki_flags & IOCB_NOWAIT))
+		req->f.iocb.ki_complete = nvmet_file_io_done;
+
+	ret = nvmet_file_submit_bvec(req, pos, bv_cnt, total_len, ki_flags);
+
+	switch (ret) {
+	case -EIOCBQUEUED:
+		return true;
+	case -EAGAIN:
+		if (WARN_ON_ONCE(!(ki_flags & IOCB_NOWAIT)))
+			goto complete;
+		return false;
+	case -EOPNOTSUPP:
+		/*
+		 * For file systems returning error -EOPNOTSUPP, handle
+		 * IOCB_NOWAIT error case separately and retry without
+		 * IOCB_NOWAIT.
+		 */
+		if ((ki_flags & IOCB_NOWAIT))
+			return false;
+		break;
+	}
+
+complete:
+	nvmet_file_io_done(&req->f.iocb, ret, 0);
+	return true;
 }
 
 static void nvmet_file_buffered_io_work(struct work_struct *w)
 {
 	struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 
-	nvmet_file_execute_rw(req);
+	nvmet_file_execute_io(req, 0);
 }
 
-static void nvmet_file_execute_rw_buffered_io(struct nvmet_req *req)
+static void nvmet_file_submit_buffered_io(struct nvmet_req *req)
 {
 	INIT_WORK(&req->f.work, nvmet_file_buffered_io_work);
 	queue_work(buffered_io_wq, &req->f.work);
 }
 
+static void nvmet_file_execute_rw(struct nvmet_req *req)
+{
+	ssize_t nr_bvec = DIV_ROUND_UP(req->data_len, PAGE_SIZE);
+
+	if (!req->sg_cnt || !nr_bvec) {
+		nvmet_req_complete(req, 0);
+		return;
+	}
+
+	if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
+		req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
+				GFP_KERNEL);
+	else
+		req->f.bvec = req->inline_bvec;
+
+	if (unlikely(!req->f.bvec)) {
+		/* fallback under memory pressure */
+		req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
+		req->f.mpool_alloc = true;
+	} else
+		req->f.mpool_alloc = false;
+
+	if (req->ns->buffered_io) {
+		if (likely(!req->f.mpool_alloc) &&
+				nvmet_file_execute_io(req, IOCB_NOWAIT))
+			return;
+		nvmet_file_submit_buffered_io(req);
+	} else
+		nvmet_file_execute_io(req, 0);
+}
+
 u16 nvmet_file_flush(struct nvmet_req *req)
 {
 	if (vfs_fsync(req->ns->file, 1) < 0)
@@ -320,10 +361,7 @@ u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
 	switch (cmd->common.opcode) {
 	case nvme_cmd_read:
 	case nvme_cmd_write:
-		if (req->ns->buffered_io)
-			req->execute = nvmet_file_execute_rw_buffered_io;
-		else
-			req->execute = nvmet_file_execute_rw;
+		req->execute = nvmet_file_execute_rw;
 		req->data_len = nvmet_rw_len(req);
 		return 0;
 	case nvme_cmd_flush: