blob: 8c42b3a8c420ab29a0b79f29df5c9e55c1ce73d9 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* NVMe Over Fabrics Target File I/O commands implementation.
* Copyright (c) 2017-2018 Western Digital Corporation or its
* affiliates.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/uio.h>
#include <linux/falloc.h>
#include <linux/file.h>
#include "nvmet.h"
#define NVMET_MAX_MPOOL_BVEC 16
#define NVMET_MIN_MPOOL_OBJ 16
void nvmet_file_ns_disable(struct nvmet_ns *ns)
{
if (ns->file) {
mempool_destroy(ns->bvec_pool);
ns->bvec_pool = NULL;
kmem_cache_destroy(ns->bvec_cache);
ns->bvec_cache = NULL;
fput(ns->file);
ns->file = NULL;
}
}
int nvmet_file_ns_enable(struct nvmet_ns *ns)
{
int ret;
struct kstat stat;
ns->file = filp_open(ns->device_path,
O_RDWR | O_LARGEFILE | O_DIRECT, 0);
if (IS_ERR(ns->file)) {
pr_err("failed to open file %s: (%ld)\n",
ns->device_path, PTR_ERR(ns->file));
return PTR_ERR(ns->file);
}
ret = vfs_getattr(&ns->file->f_path,
&stat, STATX_SIZE, AT_STATX_FORCE_SYNC);
if (ret)
goto err;
ns->size = stat.size;
ns->blksize_shift = file_inode(ns->file)->i_blkbits;
ns->bvec_cache = kmem_cache_create("nvmet-bvec",
NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec),
0, SLAB_HWCACHE_ALIGN, NULL);
if (!ns->bvec_cache) {
ret = -ENOMEM;
goto err;
}
ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab,
mempool_free_slab, ns->bvec_cache);
if (!ns->bvec_pool) {
ret = -ENOMEM;
goto err;
}
return ret;
err:
ns->size = 0;
ns->blksize_shift = 0;
nvmet_file_ns_disable(ns);
return ret;
}
static void nvmet_file_init_bvec(struct bio_vec *bv, struct sg_page_iter *iter)
{
bv->bv_page = sg_page_iter_page(iter);
bv->bv_offset = iter->sg->offset;
bv->bv_len = PAGE_SIZE - iter->sg->offset;
}
static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
unsigned long nr_segs, size_t count)
{
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;
if (req->cmd->rw.opcode == nvme_cmd_write) {
if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
ki_flags = IOCB_DSYNC;
call_iter = req->ns->file->f_op->write_iter;
rw = WRITE;
} else {
call_iter = req->ns->file->f_op->read_iter;
rw = READ;
}
iov_iter_bvec(&iter, ITER_BVEC | rw, req->f.bvec, nr_segs, count);
iocb->ki_pos = pos;
iocb->ki_filp = req->ns->file;
iocb->ki_flags = IOCB_DIRECT | ki_flags;
ret = call_iter(iocb, &iter);
if (ret != -EIOCBQUEUED && iocb->ki_complete)
iocb->ki_complete(iocb, ret, 0);
return ret;
}
static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2)
{
struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
if (req->f.bvec != req->inline_bvec) {
if (likely(req->f.mpool_alloc == false))
kfree(req->f.bvec);
else
mempool_free(req->f.bvec, req->ns->bvec_pool);
}
nvmet_req_complete(req, ret != req->data_len ?
NVME_SC_INTERNAL | NVME_SC_DNR : 0);
}
static void nvmet_file_execute_rw(struct nvmet_req *req)
{
ssize_t nr_bvec = DIV_ROUND_UP(req->data_len, PAGE_SIZE);
struct sg_page_iter sg_pg_iter;
unsigned long bv_cnt = 0;
bool is_sync = false;
size_t len = 0, total_len = 0;
ssize_t ret = 0;
loff_t pos;
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;
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;
}
pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
memset(&req->f.iocb, 0, sizeof(struct kiocb));
for_each_sg_page(req->sg, &sg_pg_iter, req->sg_cnt, 0) {
nvmet_file_init_bvec(&req->f.bvec[bv_cnt], &sg_pg_iter);
len += req->f.bvec[bv_cnt].bv_len;
total_len += req->f.bvec[bv_cnt].bv_len;
bv_cnt++;
WARN_ON_ONCE((nr_bvec - 1) < 0);
if (unlikely(is_sync) &&
(nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) {
ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len);
if (ret < 0)
goto out;
pos += len;
bv_cnt = 0;
len = 0;
}
nr_bvec--;
}
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;
}
req->f.iocb.ki_complete = nvmet_file_io_done;
nvmet_file_submit_bvec(req, pos, bv_cnt, total_len);
}
static void nvmet_file_flush_work(struct work_struct *w)
{
struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
int ret;
ret = vfs_fsync(req->ns->file, 1);
nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
}
static void nvmet_file_execute_flush(struct nvmet_req *req)
{
INIT_WORK(&req->f.work, nvmet_file_flush_work);
schedule_work(&req->f.work);
}
static void nvmet_file_execute_discard(struct nvmet_req *req)
{
int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
struct nvme_dsm_range range;
loff_t offset;
loff_t len;
int i, ret;
for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
if (nvmet_copy_from_sgl(req, i * sizeof(range), &range,
sizeof(range)))
break;
offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
len = le32_to_cpu(range.nlb) << req->ns->blksize_shift;
ret = vfs_fallocate(req->ns->file, mode, offset, len);
if (ret)
break;
}
nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
}
static void nvmet_file_dsm_work(struct work_struct *w)
{
struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
switch (le32_to_cpu(req->cmd->dsm.attributes)) {
case NVME_DSMGMT_AD:
nvmet_file_execute_discard(req);
return;
case NVME_DSMGMT_IDR:
case NVME_DSMGMT_IDW:
default:
/* Not supported yet */
nvmet_req_complete(req, 0);
return;
}
}
static void nvmet_file_execute_dsm(struct nvmet_req *req)
{
INIT_WORK(&req->f.work, nvmet_file_dsm_work);
schedule_work(&req->f.work);
}
static void nvmet_file_write_zeroes_work(struct work_struct *w)
{
struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
loff_t offset;
loff_t len;
int ret;
offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
req->ns->blksize_shift);
ret = vfs_fallocate(req->ns->file, mode, offset, len);
nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
}
static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
{
INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
schedule_work(&req->f.work);
}
u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
{
struct nvme_command *cmd = req->cmd;
switch (cmd->common.opcode) {
case nvme_cmd_read:
case nvme_cmd_write:
req->execute = nvmet_file_execute_rw;
req->data_len = nvmet_rw_len(req);
return 0;
case nvme_cmd_flush:
req->execute = nvmet_file_execute_flush;
req->data_len = 0;
return 0;
case nvme_cmd_dsm:
req->execute = nvmet_file_execute_dsm;
req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
sizeof(struct nvme_dsm_range);
return 0;
case nvme_cmd_write_zeroes:
req->execute = nvmet_file_execute_write_zeroes;
req->data_len = 0;
return 0;
default:
pr_err("unhandled cmd for file ns %d on qid %d\n",
cmd->common.opcode, req->sq->qid);
return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
}
}