kernel-ark/fs/exofs/ios.c
Boaz Harrosh 04dc1e88ad exofs: Multi-device mirror support
This patch changes on-disk format, it is accompanied with a parallel
patch to mkfs.exofs that enables multi-device capabilities.

After this patch, old exofs will refuse to mount a new formatted FS and
new exofs will refuse an old format. This is done by moving the magic
field offset inside the FSCB. A new FSCB *version* field was added. In
the future, exofs will refuse to mount unmatched FSCB version. To
up-grade or down-grade an exofs one must use mkfs.exofs --upgrade option
before mounting.

Introduced, a new object that contains a *device-table*. This object
contains the default *data-map* and a linear array of devices
information, which identifies the devices used in the filesystem. This
object is only written to offline by mkfs.exofs. This is why it is kept
separate from the FSCB, since the later is written to while mounted.

Same partition number, same object number is used on all devices only
the device varies.

* define the new format, then load the device table on mount time make
  sure every thing is supported.

* Change I/O engine to now support Mirror IO, .i.e write same data
  to multiple devices, read from a random device to spread the
  read-load from multiple clients (TODO: stripe read)

Implementation notes:
 A few points introduced in previous patch should be mentioned here:

* Special care was made so absolutlly all operation that have any chance
  of failing are done before any osd-request is executed. This is to
  minimize the need for a data consistency recovery, to only real IO
  errors.

* Each IO state has a kref. It starts at 1, any osd-request executed
  will increment the kref, finally when all are executed the first ref
  is dropped. At IO-done, each request completion decrements the kref,
  the last one to return executes the internal _last_io() routine.
  _last_io() will call the registered io_state_done. On sync mode a
  caller does not supply a done method, indicating a synchronous
  request, the caller is put to sleep and a special io_state_done is
  registered that will awaken the caller. Though also in sync mode all
  operations are executed in parallel.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10 09:59:23 +02:00

422 lines
9.2 KiB
C

/*
* Copyright (C) 2005, 2006
* Avishay Traeger (avishay@gmail.com)
* Copyright (C) 2008, 2009
* Boaz Harrosh <bharrosh@panasas.com>
*
* This file is part of exofs.
*
* exofs is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation. Since it is based on ext2, and the only
* valid version of GPL for the Linux kernel is version 2, the only valid
* version of GPL for exofs is version 2.
*
* exofs is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with exofs; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <scsi/scsi_device.h>
#include "exofs.h"
void exofs_make_credential(u8 cred_a[OSD_CAP_LEN], const struct osd_obj_id *obj)
{
osd_sec_init_nosec_doall_caps(cred_a, obj, false, true);
}
int exofs_read_kern(struct osd_dev *od, u8 *cred, struct osd_obj_id *obj,
u64 offset, void *p, unsigned length)
{
struct osd_request *or = osd_start_request(od, GFP_KERNEL);
/* struct osd_sense_info osi = {.key = 0};*/
int ret;
if (unlikely(!or)) {
EXOFS_DBGMSG("%s: osd_start_request failed.\n", __func__);
return -ENOMEM;
}
ret = osd_req_read_kern(or, obj, offset, p, length);
if (unlikely(ret)) {
EXOFS_DBGMSG("%s: osd_req_read_kern failed.\n", __func__);
goto out;
}
ret = osd_finalize_request(or, 0, cred, NULL);
if (unlikely(ret)) {
EXOFS_DBGMSG("Faild to osd_finalize_request() => %d\n", ret);
goto out;
}
ret = osd_execute_request(or);
if (unlikely(ret))
EXOFS_DBGMSG("osd_execute_request() => %d\n", ret);
/* osd_req_decode_sense(or, ret); */
out:
osd_end_request(or);
return ret;
}
int exofs_get_io_state(struct exofs_sb_info *sbi, struct exofs_io_state** pios)
{
struct exofs_io_state *ios;
/*TODO: Maybe use kmem_cach per sbi of size
* exofs_io_state_size(sbi->s_numdevs)
*/
ios = kzalloc(exofs_io_state_size(sbi->s_numdevs), GFP_KERNEL);
if (unlikely(!ios)) {
*pios = NULL;
return -ENOMEM;
}
ios->sbi = sbi;
ios->obj.partition = sbi->s_pid;
*pios = ios;
return 0;
}
void exofs_put_io_state(struct exofs_io_state *ios)
{
if (ios) {
unsigned i;
for (i = 0; i < ios->numdevs; i++) {
struct exofs_per_dev_state *per_dev = &ios->per_dev[i];
if (per_dev->or)
osd_end_request(per_dev->or);
if (per_dev->bio)
bio_put(per_dev->bio);
}
kfree(ios);
}
}
static void _sync_done(struct exofs_io_state *ios, void *p)
{
struct completion *waiting = p;
complete(waiting);
}
static void _last_io(struct kref *kref)
{
struct exofs_io_state *ios = container_of(
kref, struct exofs_io_state, kref);
ios->done(ios, ios->private);
}
static void _done_io(struct osd_request *or, void *p)
{
struct exofs_io_state *ios = p;
kref_put(&ios->kref, _last_io);
}
static int exofs_io_execute(struct exofs_io_state *ios)
{
DECLARE_COMPLETION_ONSTACK(wait);
bool sync = (ios->done == NULL);
int i, ret;
if (sync) {
ios->done = _sync_done;
ios->private = &wait;
}
for (i = 0; i < ios->numdevs; i++) {
struct osd_request *or = ios->per_dev[i].or;
if (unlikely(!or))
continue;
ret = osd_finalize_request(or, 0, ios->cred, NULL);
if (unlikely(ret)) {
EXOFS_DBGMSG("Faild to osd_finalize_request() => %d\n",
ret);
return ret;
}
}
kref_init(&ios->kref);
for (i = 0; i < ios->numdevs; i++) {
struct osd_request *or = ios->per_dev[i].or;
if (unlikely(!or))
continue;
kref_get(&ios->kref);
osd_execute_request_async(or, _done_io, ios);
}
kref_put(&ios->kref, _last_io);
ret = 0;
if (sync) {
wait_for_completion(&wait);
ret = exofs_check_io(ios, NULL);
}
return ret;
}
int exofs_check_io(struct exofs_io_state *ios, u64 *resid)
{
enum osd_err_priority acumulated_osd_err = 0;
int acumulated_lin_err = 0;
int i;
for (i = 0; i < ios->numdevs; i++) {
struct osd_sense_info osi;
int ret = osd_req_decode_sense(ios->per_dev[i].or, &osi);
if (likely(!ret))
continue;
if (unlikely(ret == -EFAULT)) {
EXOFS_DBGMSG("%s: EFAULT Need page clear\n", __func__);
/*FIXME: All the pages in this device range should:
* clear_highpage(page);
*/
}
if (osi.osd_err_pri >= acumulated_osd_err) {
acumulated_osd_err = osi.osd_err_pri;
acumulated_lin_err = ret;
}
}
/* TODO: raid specific residual calculations */
if (resid) {
if (likely(!acumulated_lin_err))
*resid = 0;
else
*resid = ios->length;
}
return acumulated_lin_err;
}
int exofs_sbi_create(struct exofs_io_state *ios)
{
int i, ret;
for (i = 0; i < ios->sbi->s_numdevs; i++) {
struct osd_request *or;
or = osd_start_request(ios->sbi->s_ods[i], GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
ret = -ENOMEM;
goto out;
}
ios->per_dev[i].or = or;
ios->numdevs++;
osd_req_create_object(or, &ios->obj);
}
ret = exofs_io_execute(ios);
out:
return ret;
}
int exofs_sbi_remove(struct exofs_io_state *ios)
{
int i, ret;
for (i = 0; i < ios->sbi->s_numdevs; i++) {
struct osd_request *or;
or = osd_start_request(ios->sbi->s_ods[i], GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
ret = -ENOMEM;
goto out;
}
ios->per_dev[i].or = or;
ios->numdevs++;
osd_req_remove_object(or, &ios->obj);
}
ret = exofs_io_execute(ios);
out:
return ret;
}
int exofs_sbi_write(struct exofs_io_state *ios)
{
int i, ret;
for (i = 0; i < ios->sbi->s_numdevs; i++) {
struct osd_request *or;
or = osd_start_request(ios->sbi->s_ods[i], GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
ret = -ENOMEM;
goto out;
}
ios->per_dev[i].or = or;
ios->numdevs++;
if (ios->bio) {
struct bio *bio;
if (i != 0) {
bio = bio_kmalloc(GFP_KERNEL,
ios->bio->bi_max_vecs);
if (unlikely(!bio)) {
ret = -ENOMEM;
goto out;
}
__bio_clone(bio, ios->bio);
bio->bi_bdev = NULL;
bio->bi_next = NULL;
ios->per_dev[i].bio = bio;
} else {
bio = ios->bio;
}
osd_req_write(or, &ios->obj, ios->offset, bio,
ios->length);
/* EXOFS_DBGMSG("write sync=%d\n", sync);*/
} else if (ios->kern_buff) {
osd_req_write_kern(or, &ios->obj, ios->offset,
ios->kern_buff, ios->length);
/* EXOFS_DBGMSG("write_kern sync=%d\n", sync);*/
} else {
osd_req_set_attributes(or, &ios->obj);
/* EXOFS_DBGMSG("set_attributes sync=%d\n", sync);*/
}
if (ios->out_attr)
osd_req_add_set_attr_list(or, ios->out_attr,
ios->out_attr_len);
if (ios->in_attr)
osd_req_add_get_attr_list(or, ios->in_attr,
ios->in_attr_len);
}
ret = exofs_io_execute(ios);
out:
return ret;
}
int exofs_sbi_read(struct exofs_io_state *ios)
{
int i, ret;
for (i = 0; i < 1; i++) {
struct osd_request *or;
unsigned first_dev = (unsigned)ios->obj.id;
first_dev %= ios->sbi->s_numdevs;
or = osd_start_request(ios->sbi->s_ods[first_dev], GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
ret = -ENOMEM;
goto out;
}
ios->per_dev[i].or = or;
ios->numdevs++;
if (ios->bio) {
osd_req_read(or, &ios->obj, ios->offset, ios->bio,
ios->length);
/* EXOFS_DBGMSG("read sync=%d\n", sync);*/
} else if (ios->kern_buff) {
osd_req_read_kern(or, &ios->obj, ios->offset,
ios->kern_buff, ios->length);
/* EXOFS_DBGMSG("read_kern sync=%d\n", sync);*/
} else {
osd_req_get_attributes(or, &ios->obj);
/* EXOFS_DBGMSG("get_attributes sync=%d\n", sync);*/
}
if (ios->out_attr)
osd_req_add_set_attr_list(or, ios->out_attr,
ios->out_attr_len);
if (ios->in_attr)
osd_req_add_get_attr_list(or, ios->in_attr,
ios->in_attr_len);
}
ret = exofs_io_execute(ios);
out:
return ret;
}
int extract_attr_from_ios(struct exofs_io_state *ios, struct osd_attr *attr)
{
struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
void *iter = NULL;
int nelem;
do {
nelem = 1;
osd_req_decode_get_attr_list(ios->per_dev[0].or,
&cur_attr, &nelem, &iter);
if ((cur_attr.attr_page == attr->attr_page) &&
(cur_attr.attr_id == attr->attr_id)) {
attr->len = cur_attr.len;
attr->val_ptr = cur_attr.val_ptr;
return 0;
}
} while (iter);
return -EIO;
}
int exofs_oi_truncate(struct exofs_i_info *oi, u64 size)
{
struct exofs_sb_info *sbi = oi->vfs_inode.i_sb->s_fs_info;
struct exofs_io_state *ios;
struct osd_attr attr;
__be64 newsize;
int i, ret;
if (exofs_get_io_state(sbi, &ios))
return -ENOMEM;
ios->obj.id = exofs_oi_objno(oi);
ios->cred = oi->i_cred;
newsize = cpu_to_be64(size);
attr = g_attr_logical_length;
attr.val_ptr = &newsize;
for (i = 0; i < sbi->s_numdevs; i++) {
struct osd_request *or;
or = osd_start_request(sbi->s_ods[i], GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
ret = -ENOMEM;
goto out;
}
ios->per_dev[i].or = or;
ios->numdevs++;
osd_req_set_attributes(or, &ios->obj);
osd_req_add_set_attr_list(or, &attr, 1);
}
ret = exofs_io_execute(ios);
out:
exofs_put_io_state(ios);
return ret;
}