mars/mars_sio.c

666 lines
14 KiB
C

// (c) 2010 Thomas Schoebel-Theuer / 1&1 Internet AG
//#define BRICK_DEBUGGING
//#define MARS_DEBUGGING
//#define IO_DEBUGGING
#define USE_VFS_READ
#define USE_VFS_WRITE
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/blkdev.h>
#include <linux/highmem.h>
#include <linux/kthread.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/splice.h>
#include "mars.h"
///////////////////////// own type definitions ////////////////////////
#include "mars_sio.h"
////////////////// own brick / input / output operations //////////////////
static int sio_ref_get(struct sio_output *output, struct mref_object *mref)
{
struct file *file;
if (atomic_read(&mref->ref_count) > 0) {
goto done;
}
file = output->filp;
if (file) {
loff_t total_size = i_size_read(file->f_mapping->host);
mref->ref_total_size = total_size;
/* Only check reads.
* Writes behind EOF are always allowed (sparse files)
*/
if (!mref->ref_may_write) {
loff_t len = total_size - mref->ref_pos;
if (unlikely(len <= 0)) {
/* Special case: allow reads starting _exactly_ at EOF when a timeout is specified.
*/
if (len < 0 || mref->ref_timeout <= 0) {
MARS_DBG("ENODATA %lld\n", len);
return -ENODATA;
}
}
// Shorten below EOF, but allow special case
if (mref->ref_len > len && len > 0) {
mref->ref_len = len;
}
}
}
/* Buffered IO.
*/
if (!mref->ref_data) {
struct sio_mref_aspect *mref_a = sio_mref_get_aspect(output->brick, mref);
if (unlikely(!mref_a))
return -EILSEQ;
if (unlikely(mref->ref_len <= 0)) {
MARS_ERR("bad ref_len = %d\n", mref->ref_len);
return -ENOMEM;
}
mref->ref_data = brick_block_alloc(mref->ref_pos, (mref_a->alloc_len = mref->ref_len));
if (unlikely(!mref->ref_data)) {
MARS_ERR("ENOMEM %d bytes\n", mref->ref_len);
return -ENOMEM;
}
#if 0 // ???
mref->ref_flags = 0;
#endif
mref_a->do_dealloc = true;
//atomic_inc(&output->total_alloc_count);
//atomic_inc(&output->alloc_count);
}
done:
atomic_inc(&mref->ref_count);
return mref->ref_len;
}
static void sio_ref_put(struct sio_output *output, struct mref_object *mref)
{
struct file *file;
struct sio_mref_aspect *mref_a;
CHECK_ATOMIC(&mref->ref_count, 1);
if (!atomic_dec_and_test(&mref->ref_count))
return;
file = output->filp;
if (file) {
mref->ref_total_size = i_size_read(file->f_mapping->host);
}
mref_a = sio_mref_get_aspect(output->brick, mref);
if (mref_a && mref_a->do_dealloc) {
brick_block_free(mref->ref_data, mref_a->alloc_len);
//atomic_dec(&output->alloc_count);
}
sio_free_mref(mref);
}
// some code borrowed from the loopback driver
static int transfer_none(int cmd,
struct page *raw_page, unsigned raw_off,
//struct page *loop_page, unsigned loop_off,
void *loop_buf,
int size)
{
#if 1
void *raw_buf = kmap_atomic(raw_page, KM_USER0) + raw_off;
//void *loop_buf = kmap_atomic(loop_page, KM_USER1) + loop_off;
if (unlikely(!raw_buf || !loop_buf)) {
MARS_ERR("transfer NULL: %p %p\n", raw_buf, loop_buf);
return -EFAULT;
}
if (cmd == READ)
memcpy(loop_buf, raw_buf, size);
else
memcpy(raw_buf, loop_buf, size);
kunmap_atomic(raw_buf, KM_USER0);
//kunmap_atomic(loop_buf, KM_USER1);
cond_resched();
#endif
return 0;
}
static
int write_aops(struct sio_output *output, struct mref_object *mref)
{
struct file *file = output->filp;
loff_t pos = mref->ref_pos;
void *data = mref->ref_data;
int len = mref->ref_len;
int ret = 0;
#ifdef USE_VFS_WRITE
mm_segment_t oldfs;
oldfs = get_fs();
set_fs(get_ds());
ret = vfs_write(file, data, len, &pos);
set_fs(oldfs);
#else
unsigned offset;
struct address_space *mapping;
if (unlikely(!file)) {
MARS_FAT("No FILE\n");
return -ENXIO;
}
mapping = file->f_mapping;
mutex_lock(&mapping->host->i_mutex);
offset = pos & ((pgoff_t)PAGE_CACHE_SIZE - 1);
while (len > 0) {
int transfer_result;
unsigned size, copied;
struct page *page = NULL;
void *fsdata;
size = PAGE_CACHE_SIZE - offset;
if (size > len)
size = len;
ret = pagecache_write_begin(file, mapping, pos, size, 0,
&page, &fsdata);
if (ret) {
MARS_ERR("cannot start pagecache_write_begin() error=%d\n", ret);
if (ret >= 0)
ret = -EIO;
goto fail;
}
//file_update_time(file);
transfer_result = transfer_none(WRITE, page, offset, data, size);
copied = size;
if (transfer_result) {
MARS_ERR("transfer error %d\n", transfer_result);
copied = 0;
}
ret = pagecache_write_end(file, mapping, pos, size, copied,
page, fsdata);
if (ret < 0 || ret != copied || transfer_result) {
MARS_ERR("write error %d\n", ret);
if (ret >= 0)
ret = -EIO;
goto fail;
}
len -= copied;
offset = 0;
pos += copied;
data += copied;
}
ret = 0;
fail:
mutex_unlock(&mapping->host->i_mutex);
#if 1
blk_run_address_space(mapping);
#endif
#endif
return ret;
}
struct cookie_data {
struct sio_output *output;
struct mref_object *mref;
};
static int
sio_splice_actor(struct pipe_inode_info *pipe,
struct pipe_buffer *buf,
struct splice_desc *sd)
{
struct cookie_data *cookie = sd->u.data;
struct mref_object *mref = cookie->mref;
struct page *page = buf->page;
void *data;
int size, ret;
ret = buf->ops->confirm(pipe, buf);
if (unlikely(ret))
return ret;
size = sd->len;
if (size > mref->ref_len)
size = mref->ref_len;
data = mref->ref_data;
if (transfer_none(READ, page, buf->offset, data, size)) {
MARS_ERR("transfer error\n");
size = -EINVAL;
}
//flush_dcache_page(p->bvec->bv_page);
return size;
}
static int
sio_direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd)
{
return __splice_from_pipe(pipe, sd, sio_splice_actor);
}
static
int read_aops(struct sio_output *output, struct mref_object *mref)
{
loff_t pos = mref->ref_pos;
int len = mref->ref_len;
int ret = -EIO;
#ifdef USE_VFS_READ
mm_segment_t oldfs;
(void) sio_direct_splice_actor; // shut up gcc
oldfs = get_fs();
set_fs(get_ds());
ret = vfs_read(output->filp, mref->ref_data, len, &pos);
set_fs(oldfs);
#else
struct cookie_data cookie = {
.output = output,
.mref = mref,
};
struct splice_desc sd = {
.len = 0,
.total_len = len,
.flags = 0,
.pos = pos,
.u.data = &cookie,
};
ret = splice_direct_to_actor(output->filp, &sd, sio_direct_splice_actor);
#endif
if (unlikely(ret < 0)) {
MARS_ERR("%p %p status=%d\n", output, mref, ret);
}
return ret;
}
static void sync_file(struct sio_output *output)
{
struct file *file = output->filp;
int ret;
#if 1
ret = vfs_fsync(file, file->f_path.dentry, 1);
if (unlikely(ret)) {
MARS_ERR("syncing pages failed: %d\n", ret);
}
return;
#endif
}
static
void _complete(struct sio_output *output, struct mref_object *mref, int err)
{
mars_trace(mref, "sio_endio");
if (err < 0) {
MARS_ERR("IO error %d at pos=%lld len=%d (mref=%p ref_data=%p)\n", err, mref->ref_pos, mref->ref_len, mref, mref->ref_data);
} else {
mref->ref_flags |= MREF_UPTODATE;
}
CHECKED_CALLBACK(mref, err, err_found);
done:
#if 0
if (mref->ref_rw) {
atomic_dec(&output->write_count);
} else {
atomic_dec(&output->read_count);
}
#endif
sio_ref_put(output, mref);
return;
err_found:
MARS_FAT("giving up...\n");
goto done;
}
/* This is called by the threads
*/
static
void _sio_ref_io(struct sio_output *output, struct mref_object *mref)
{
bool barrier = false;
int status;
if (unlikely(!output->filp)) {
status = -EINVAL;
goto done;
}
if (barrier) {
MARS_INF("got barrier request\n");
sync_file(output);
}
if (mref->ref_rw == READ) {
status = read_aops(output, mref);
} else {
status = write_aops(output, mref);
if (barrier || output->brick->o_fdsync)
sync_file(output);
}
done:
_complete(output, mref, status);
}
/* This is called from outside
*/
static
void sio_ref_io(struct sio_output *output, struct mref_object *mref)
{
int index;
struct sio_threadinfo *tinfo;
struct sio_mref_aspect *mref_a;
unsigned long flags;
mref_a = sio_mref_get_aspect(output->brick, mref);
if (unlikely(!mref_a)) {
MARS_FAT("cannot get aspect\n");
SIMPLE_CALLBACK(mref, -EINVAL);
return;
}
atomic_inc(&mref->ref_count);
index = 0;
if (mref->ref_rw == READ) {
traced_lock(&output->g_lock, flags);
index = output->index++;
traced_unlock(&output->g_lock, flags);
index = (index % WITH_THREAD) + 1;
}
tinfo = &output->tinfo[index];
MARS_IO("queueing %p on %d\n", mref, index);
traced_lock(&tinfo->lock, flags);
list_add_tail(&mref_a->io_head, &tinfo->mref_list);
traced_unlock(&tinfo->lock, flags);
wake_up_interruptible(&tinfo->event);
}
static int sio_thread(void *data)
{
struct sio_threadinfo *tinfo = data;
struct sio_output *output = tinfo->output;
MARS_INF("kthread has started.\n");
//set_user_nice(current, -20);
while (!kthread_should_stop()) {
struct list_head *tmp = NULL;
struct mref_object *mref;
struct sio_mref_aspect *mref_a;
unsigned long flags;
wait_event_interruptible_timeout(
tinfo->event,
!list_empty(&tinfo->mref_list) || kthread_should_stop(),
HZ);
tinfo->last_jiffies = jiffies;
traced_lock(&tinfo->lock, flags);
if (!list_empty(&tinfo->mref_list)) {
tmp = tinfo->mref_list.next;
list_del_init(tmp);
}
traced_unlock(&tinfo->lock, flags);
if (!tmp)
continue;
mref_a = container_of(tmp, struct sio_mref_aspect, io_head);
mref = mref_a->object;
MARS_IO("got %p %p\n", mref_a, mref);
_sio_ref_io(output, mref);
}
MARS_INF("kthread has stopped.\n");
return 0;
}
static int sio_get_info(struct sio_output *output, struct mars_info *info)
{
struct file *file = output->filp;
if (unlikely(!file || !file->f_mapping || !file->f_mapping->host))
return -EINVAL;
info->current_size = i_size_read(file->f_mapping->host);
MARS_DBG("determined file size = %lld\n", info->current_size);
info->backing_file = file;
return 0;
}
//////////////// object / aspect constructors / destructors ///////////////
static int sio_mref_aspect_init_fn(struct generic_aspect *_ini)
{
struct sio_mref_aspect *ini = (void*)_ini;
INIT_LIST_HEAD(&ini->io_head);
return 0;
}
static void sio_mref_aspect_exit_fn(struct generic_aspect *_ini)
{
struct sio_mref_aspect *ini = (void*)_ini;
(void)ini;
#if 1
CHECK_HEAD_EMPTY(&ini->io_head);
#endif
}
MARS_MAKE_STATICS(sio);
////////////////////// brick constructors / destructors ////////////////////
static int sio_brick_construct(struct sio_brick *brick)
{
return 0;
}
static int sio_switch(struct sio_brick *brick)
{
static int sio_nr = 0;
struct sio_output *output = brick->outputs[0];
const char *path = output->brick->brick_path;
int flags = O_CREAT | O_RDWR | O_LARGEFILE;
int prot = 0600;
mm_segment_t oldfs;
if (brick->o_direct) {
flags |= O_DIRECT;
MARS_INF("using O_DIRECT on %s\n", path);
}
if (brick->power.button) {
int index;
mars_power_led_off((void*)brick, false);
if (brick->power.led_on)
goto done;
oldfs = get_fs();
set_fs(get_ds());
output->filp = filp_open(path, flags, prot);
set_fs(oldfs);
if (unlikely(IS_ERR(output->filp))) {
int err = PTR_ERR(output->filp);
MARS_ERR("can't open file '%s' status=%d\n", path, err);
output->filp = NULL;
return err;
}
#if 0
{
struct address_space *mapping = output->filp->f_mapping;
int old_gfp_mask = mapping_gfp_mask(mapping);
mapping_set_gfp_mask(mapping, old_gfp_mask & ~(__GFP_IO|__GFP_FS));
}
#endif
MARS_INF("opened file '%s' as %p\n", path, output->filp);
output->index = 0;
for (index = 0; index <= WITH_THREAD; index++) {
struct sio_threadinfo *tinfo = &output->tinfo[index];
tinfo->last_jiffies = jiffies;
tinfo->thread = kthread_create(sio_thread, tinfo, "mars_sio%d", sio_nr++);
if (IS_ERR(tinfo->thread)) {
int error = PTR_ERR(tinfo->thread);
MARS_ERR("cannot create thread, status=%d\n", error);
filp_close(output->filp, NULL);
output->filp = NULL;
return error;
}
get_task_struct(tinfo->thread);
wake_up_process(tinfo->thread);
}
mars_power_led_on((void*)brick, true);
} else {
mars_power_led_on((void*)brick, false);
if (output->filp) {
int index;
for (index = 0; index <= WITH_THREAD; index++) {
struct sio_threadinfo *tinfo = &output->tinfo[index];
MARS_DBG("stopping thread %d\n", index);
kthread_stop(tinfo->thread);
put_task_struct(tinfo->thread);
tinfo->thread = NULL;
}
MARS_DBG("closing file\n");
filp_close(output->filp, NULL);
output->filp = NULL;
}
mars_power_led_off((void*)brick, true);
}
done:
return 0;
}
static int sio_output_construct(struct sio_output *output)
{
int index;
spin_lock_init(&output->g_lock);
for (index = 0; index <= WITH_THREAD; index++) {
struct sio_threadinfo *tinfo = &output->tinfo[index];
tinfo->output = output;
spin_lock_init(&tinfo->lock);
init_waitqueue_head(&tinfo->event);
INIT_LIST_HEAD(&tinfo->mref_list);
}
return 0;
}
static int sio_output_destruct(struct sio_output *output)
{
return 0;
}
///////////////////////// static structs ////////////////////////
static struct sio_brick_ops sio_brick_ops = {
.brick_switch = sio_switch,
};
static struct sio_output_ops sio_output_ops = {
.mref_get = sio_ref_get,
.mref_put = sio_ref_put,
.mref_io = sio_ref_io,
.mars_get_info = sio_get_info,
};
const struct sio_input_type sio_input_type = {
.type_name = "sio_input",
.input_size = sizeof(struct sio_input),
};
static const struct sio_input_type *sio_input_types[] = {
&sio_input_type,
};
const struct sio_output_type sio_output_type = {
.type_name = "sio_output",
.output_size = sizeof(struct sio_output),
.master_ops = &sio_output_ops,
.output_construct = &sio_output_construct,
.output_destruct = &sio_output_destruct,
};
static const struct sio_output_type *sio_output_types[] = {
&sio_output_type,
};
const struct sio_brick_type sio_brick_type = {
.type_name = "sio_brick",
.brick_size = sizeof(struct sio_brick),
.max_inputs = 0,
.max_outputs = 1,
.master_ops = &sio_brick_ops,
.aspect_types = sio_aspect_types,
.default_input_types = sio_input_types,
.default_output_types = sio_output_types,
.brick_construct = &sio_brick_construct,
};
EXPORT_SYMBOL_GPL(sio_brick_type);
////////////////// module init stuff /////////////////////////
int __init init_mars_sio(void)
{
MARS_INF("init_sio()\n");
_sio_brick_type = (void*)&sio_brick_type;
return sio_register_brick_type();
}
void __exit exit_mars_sio(void)
{
MARS_INF("exit_sio()\n");
sio_unregister_brick_type();
}
#ifndef CONFIG_MARS_HAVE_BIGMODULE
MODULE_DESCRIPTION("MARS sio brick");
MODULE_AUTHOR("Thomas Schoebel-Theuer <tst@1und1.de>");
MODULE_LICENSE("GPL");
module_init(init_mars_sio);
module_exit(exit_mars_sio);
#endif