static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
const struct lu_buf *buf, loff_t *pos,
struct thandle *th, struct lustre_capa *capa,
int ignore_quota)
{
struct osd_object *obj = osd_dt_obj(dt);
struct osd_device *osd = osd_obj2dev(obj);
struct osd_thandle *oh;
uint64_t offset = *pos;
int rc;
ENTRY;
LASSERT(dt_object_exists(dt));
LASSERT(obj->oo_db);
LASSERT(th != NULL);
oh = container_of0(th, struct osd_thandle, ot_super);
record_start_io(osd, WRITE, (buf->lb_len >> PAGE_CACHE_SHIFT), 0);
dmu_write(osd->od_os, obj->oo_db->db_object, offset,
(uint64_t)buf->lb_len, buf->lb_buf, oh->ot_tx);
write_lock(&obj->oo_attr_lock);
if (obj->oo_attr.la_size < offset + buf->lb_len) {
obj->oo_attr.la_size = offset + buf->lb_len;
write_unlock(&obj->oo_attr_lock);
/* osd_object_sa_update() will be copying directly from oo_attr
* into dbuf. any update within a single txg will copy the
* most actual */
rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
&obj->oo_attr.la_size, 8, oh);
if (unlikely(rc))
GOTO(out, rc);
} else {
write_unlock(&obj->oo_attr_lock);
}
*pos += buf->lb_len;
rc = buf->lb_len;
out:
record_end_io(osd, WRITE, 0, buf->lb_len);
RETURN(rc);
}
static ssize_t osd_read(const struct lu_env *env, struct dt_object *dt,
struct lu_buf *buf, loff_t *pos,
struct lustre_capa *capa)
{
struct osd_object *obj = osd_dt_obj(dt);
struct osd_device *osd = osd_obj2dev(obj);
uint64_t old_size;
int size = buf->lb_len;
int rc;
unsigned long start;
LASSERT(dt_object_exists(dt));
LASSERT(obj->oo_db);
start = cfs_time_current();
read_lock(&obj->oo_attr_lock);
old_size = obj->oo_attr.la_size;
read_unlock(&obj->oo_attr_lock);
if (*pos + size > old_size) {
if (old_size < *pos)
return 0;
else
size = old_size - *pos;
}
record_start_io(osd, READ, (size >> PAGE_CACHE_SHIFT), 0);
rc = -dmu_read(osd->od_os, obj->oo_db->db_object, *pos, size,
buf->lb_buf, DMU_READ_PREFETCH);
record_end_io(osd, READ, cfs_time_current() - start, size);
if (rc == 0) {
rc = size;
*pos += size;
}
return rc;
}
/**
* Prepare buffers for read.
*
* The function maps the range described by \a off and \a len to \a lnb array.
* dmu_buf_hold_array_by_bonus() finds/creates appropriate ARC buffers, then
* we fill \a lnb array with the pages storing ARC buffers. Notice the current
* implementationt passes TRUE to dmu_buf_hold_array_by_bonus() to fill ARC
* buffers with actual data, I/O is done in the conext of osd_bufs_get_read().
* A better implementation would just return the buffers (potentially unfilled)
* and subsequent osd_read_prep() would do I/O for many ranges concurrently.
*
* \param[in] env environment
* \param[in] obj object
* \param[in] off offset in bytes
* \param[in] len the number of bytes to access
* \param[out] lnb array of local niobufs pointing to the buffers with data
*
* \retval 0 for success
* \retval negative error number of failure
*/
static int osd_bufs_get_read(const struct lu_env *env, struct osd_object *obj,
loff_t off, ssize_t len, struct niobuf_local *lnb)
{
struct osd_device *osd = osd_obj2dev(obj);
unsigned long start = cfs_time_current();
int rc, i, numbufs, npages = 0;
dmu_buf_t **dbp;
ENTRY;
record_start_io(osd, READ, 0);
/* grab buffers for read:
* OSD API let us to grab buffers first, then initiate IO(s)
* so that all required IOs will be done in parallel, but at the
* moment DMU doesn't provide us with a method to grab buffers.
* If we discover this is a vital for good performance we
* can get own replacement for dmu_buf_hold_array_by_bonus().
*/
while (len > 0) {
rc = -dmu_buf_hold_array_by_bonus(obj->oo_db, off, len, TRUE,
osd_zerocopy_tag, &numbufs,
&dbp);
if (unlikely(rc))
GOTO(err, rc);
for (i = 0; i < numbufs; i++) {
int bufoff, tocpy, thispage;
void *dbf = dbp[i];
LASSERT(len > 0);
atomic_inc(&osd->od_zerocopy_pin);
bufoff = off - dbp[i]->db_offset;
tocpy = min_t(int, dbp[i]->db_size - bufoff, len);
/* kind of trick to differentiate dbuf vs. arcbuf */
LASSERT(((unsigned long)dbp[i] & 1) == 0);
dbf = (void *) ((unsigned long)dbp[i] | 1);
while (tocpy > 0) {
thispage = PAGE_CACHE_SIZE;
thispage -= bufoff & (PAGE_CACHE_SIZE - 1);
thispage = min(tocpy, thispage);
lnb->lnb_rc = 0;
lnb->lnb_file_offset = off;
lnb->lnb_page_offset = bufoff & ~PAGE_MASK;
lnb->lnb_len = thispage;
lnb->lnb_page = kmem_to_page(dbp[i]->db_data +
bufoff);
/* mark just a single slot: we need this
* reference to dbuf to be released once */
lnb->lnb_data = dbf;
dbf = NULL;
tocpy -= thispage;
len -= thispage;
bufoff += thispage;
off += thispage;
npages++;
lnb++;
}
/* steal dbuf so dmu_buf_rele_array() can't release
* it */
dbp[i] = NULL;
}
dmu_buf_rele_array(dbp, numbufs, osd_zerocopy_tag);
}
record_end_io(osd, READ, cfs_time_current() - start,
npages * PAGE_SIZE, npages);
RETURN(npages);
err:
LASSERT(rc < 0);
osd_bufs_put(env, &obj->oo_dt, lnb - npages, npages);
RETURN(rc);
}
