blob: 6be6e59d273bb72c43bc2b106fc2df8ddfbd5622 [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 <linux/fs.h>
#include "nvmet.h"
#define NVMET_MAX_MPOOL_BVEC 16
#define NVMET_MIN_MPOOL_OBJ 16
int nvmet_file_ns_revalidate(struct nvmet_ns *ns)
{
struct kstat stat;
int ret;
ret = vfs_getattr(&ns->file->f_path, &stat, STATX_SIZE,
AT_STATX_FORCE_SYNC);
if (!ret)
ns->size = stat.size;
return ret;
}
void nvmet_file_ns_disable(struct nvmet_ns *ns)
{
if (ns->file) {
if (ns->buffered_io)
flush_workqueue(buffered_io_wq);
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 flags = O_RDWR | O_LARGEFILE;
int ret;
if (!ns->buffered_io)
flags |= O_DIRECT;
ns->file = filp_open(ns->device_path, flags, 0);
if (IS_ERR(ns->file)) {
ret = PTR_ERR(ns->file);
pr_err("failed to open file %s: (%d)\n",
ns->device_path, ret);
ns->file = NULL;
return ret;
}
ret = nvmet_file_ns_revalidate(ns);
if (ret)
goto err;
/*
* i_blkbits can be greater than the universally accepted upper bound,
* so make sure we export a sane namespace lba_shift.
*/
ns->blksize_shift = min_t(u8,
file_inode(ns->file)->i_blkbits, 12);
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 scatterlist *sg)
{
bv->bv_page = sg_page(sg);
bv->bv_offset = sg->offset;
bv->bv_len = sg->length;
}
static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
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 rw;
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, rw, req->f.bvec, nr_segs, count);
iocb->ki_pos = pos;
iocb->ki_filp = req->ns->file;
iocb->ki_flags = ki_flags | iocb_flags(req->ns->file);
return call_iter(iocb, &iter);
}
static void nvmet_file_io_done(struct kiocb *iocb, long ret)
{
struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
u16 status = NVME_SC_SUCCESS;
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);
}
if (unlikely(ret != req->transfer_len))
status = errno_to_nvme_status(req, ret);
nvmet_req_complete(req, status);
}
static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags)
{
ssize_t nr_bvec = req->sg_cnt;
unsigned long bv_cnt = 0;
bool is_sync = false;
size_t len = 0, total_len = 0;
ssize_t ret = 0;
loff_t pos;
int i;
struct scatterlist *sg;
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->transfer_len > req->ns->size)) {
nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
return true;
}
memset(&req->f.iocb, 0, sizeof(struct kiocb));
for_each_sg(req->sg, sg, req->sg_cnt, i) {
nvmet_file_init_bvec(&req->f.bvec[bv_cnt], sg);
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, 0);
if (ret < 0)
goto complete;
pos += len;
bv_cnt = 0;
len = 0;
}
nr_bvec--;
}
if (WARN_ON_ONCE(total_len != req->transfer_len)) {
ret = -EIO;
goto complete;
}
if (unlikely(is_sync)) {
ret = total_len;
goto complete;
}
/*
* 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);
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_io(req, 0);
}
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 = req->sg_cnt;
if (!nvmet_check_transfer_len(req, nvmet_rw_data_len(req)))
return;
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) &&
(req->ns->file->f_mode & FMODE_NOWAIT) &&
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)
{
return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
}
static void nvmet_file_flush_work(struct work_struct *w)
{
struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
nvmet_req_complete(req, nvmet_file_flush(req));
}
static void nvmet_file_execute_flush(struct nvmet_req *req)
{
if (!nvmet_check_transfer_len(req, 0))
return;
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, len;
u16 status = 0;
int ret;
int i;
for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
sizeof(range));
if (status)
break;
offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
len = le32_to_cpu(range.nlb);
len <<= req->ns->blksize_shift;
if (offset + len > req->ns->size) {
req->error_slba = le64_to_cpu(range.slba);
status = errno_to_nvme_status(req, -ENOSPC);
break;
}
ret = vfs_fallocate(req->ns->file, mode, offset, len);
if (ret && ret != -EOPNOTSUPP) {
req->error_slba = le64_to_cpu(range.slba);
status = errno_to_nvme_status(req, ret);
break;
}
}
nvmet_req_complete(req, status);
}
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)
{
if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
return;
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);
if (unlikely(offset + len > req->ns->size)) {
nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
return;
}
ret = vfs_fallocate(req->ns->file, mode, offset, len);
nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0);
}
static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
{
if (!nvmet_check_transfer_len(req, 0))
return;
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)
{
switch (req->cmd->common.opcode) {
case nvme_cmd_read:
case nvme_cmd_write:
req->execute = nvmet_file_execute_rw;
return 0;
case nvme_cmd_flush:
req->execute = nvmet_file_execute_flush;
return 0;
case nvme_cmd_dsm:
req->execute = nvmet_file_execute_dsm;
return 0;
case nvme_cmd_write_zeroes:
req->execute = nvmet_file_execute_write_zeroes;
return 0;
default:
return nvmet_report_invalid_opcode(req);
}
}