pnfs-obj: osd raid engine read/write implementation
With the use of the in-kernel osd library. Implement read/write
of data from/to osd-objects according to information specified
in the objects-layout.
Support for stripping over mirrors with a received stripe_unit.
There are however a few constrains which are not supported:
1. Stripe Unit must be a multiple of PAGE_SIZE
2. stripe length (stripe_unit * number_of_stripes) can not be
bigger then 32bit.
Also support raid-groups and partial-layout. Partial-layout is
when not all the groups are received on the line, addressing
only a partial range of the file.
TODO:
Only raid0! raid 4/5/6 support will come at later stage
A none supported layout will send IO through the MDS
[Important fallout from the last rebase]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
[gfp_flags]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index 353821f..cc92d3b 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -46,6 +46,10 @@
#define _LLU(x) ((unsigned long long)x)
+enum { BIO_MAX_PAGES_KMALLOC =
+ (PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),
+};
+
struct objio_dev_ent {
struct nfs4_deviceid_node id_node;
struct osd_dev *od;
@@ -136,6 +140,31 @@
return container_of(lseg, struct objio_segment, lseg);
}
+struct objio_state;
+typedef ssize_t (*objio_done_fn)(struct objio_state *ios);
+
+struct objio_state {
+ /* Generic layer */
+ struct objlayout_io_state ol_state;
+
+ struct objio_segment *layout;
+
+ struct kref kref;
+ objio_done_fn done;
+ void *private;
+
+ unsigned long length;
+ unsigned numdevs; /* Actually used devs in this IO */
+ /* A per-device variable array of size numdevs */
+ struct _objio_per_comp {
+ struct bio *bio;
+ struct osd_request *or;
+ unsigned long length;
+ u64 offset;
+ unsigned dev;
+ } per_dev[];
+};
+
/* Send and wait for a get_device_info of devices in the layout,
then look them up with the osd_initiator library */
static struct objio_dev_ent *_device_lookup(struct pnfs_layout_hdr *pnfslay,
@@ -359,6 +388,578 @@
kfree(objio_seg);
}
+int objio_alloc_io_state(struct pnfs_layout_segment *lseg,
+ struct objlayout_io_state **outp,
+ gfp_t gfp_flags)
+{
+ struct objio_segment *objio_seg = OBJIO_LSEG(lseg);
+ struct objio_state *ios;
+ const unsigned first_size = sizeof(*ios) +
+ objio_seg->num_comps * sizeof(ios->per_dev[0]);
+
+ ios = kzalloc(first_size, gfp_flags);
+ if (unlikely(!ios))
+ return -ENOMEM;
+
+ ios->layout = objio_seg;
+
+ *outp = &ios->ol_state;
+ return 0;
+}
+
+void objio_free_io_state(struct objlayout_io_state *ol_state)
+{
+ struct objio_state *ios = container_of(ol_state, struct objio_state,
+ ol_state);
+
+ kfree(ios);
+}
+
+static void _clear_bio(struct bio *bio)
+{
+ struct bio_vec *bv;
+ unsigned i;
+
+ __bio_for_each_segment(bv, bio, i, 0) {
+ unsigned this_count = bv->bv_len;
+
+ if (likely(PAGE_SIZE == this_count))
+ clear_highpage(bv->bv_page);
+ else
+ zero_user(bv->bv_page, bv->bv_offset, this_count);
+ }
+}
+
+static int _io_check(struct objio_state *ios, bool is_write)
+{
+ enum osd_err_priority oep = OSD_ERR_PRI_NO_ERROR;
+ int lin_ret = 0;
+ int i;
+
+ for (i = 0; i < ios->numdevs; i++) {
+ struct osd_sense_info osi;
+ struct osd_request *or = ios->per_dev[i].or;
+ unsigned dev;
+ int ret;
+
+ if (!or)
+ continue;
+
+ ret = osd_req_decode_sense(or, &osi);
+ if (likely(!ret))
+ continue;
+
+ if (OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) {
+ /* start read offset passed endof file */
+ BUG_ON(is_write);
+ _clear_bio(ios->per_dev[i].bio);
+ dprintk("%s: start read offset passed end of file "
+ "offset=0x%llx, length=0x%lx\n", __func__,
+ _LLU(ios->per_dev[i].offset),
+ ios->per_dev[i].length);
+
+ continue; /* we recovered */
+ }
+ dev = ios->per_dev[i].dev;
+
+ if (osi.osd_err_pri >= oep) {
+ oep = osi.osd_err_pri;
+ lin_ret = ret;
+ }
+ }
+
+ return lin_ret;
+}
+
+/*
+ * Common IO state helpers.
+ */
+static void _io_free(struct objio_state *ios)
+{
+ unsigned i;
+
+ for (i = 0; i < ios->numdevs; i++) {
+ struct _objio_per_comp *per_dev = &ios->per_dev[i];
+
+ if (per_dev->or) {
+ osd_end_request(per_dev->or);
+ per_dev->or = NULL;
+ }
+
+ if (per_dev->bio) {
+ bio_put(per_dev->bio);
+ per_dev->bio = NULL;
+ }
+ }
+}
+
+struct osd_dev *_io_od(struct objio_state *ios, unsigned dev)
+{
+ unsigned min_dev = ios->layout->comps_index;
+ unsigned max_dev = min_dev + ios->layout->num_comps;
+
+ BUG_ON(dev < min_dev || max_dev <= dev);
+ return ios->layout->ods[dev - min_dev]->od;
+}
+
+struct _striping_info {
+ u64 obj_offset;
+ u64 group_length;
+ unsigned dev;
+ unsigned unit_off;
+};
+
+static void _calc_stripe_info(struct objio_state *ios, u64 file_offset,
+ struct _striping_info *si)
+{
+ u32 stripe_unit = ios->layout->stripe_unit;
+ u32 group_width = ios->layout->group_width;
+ u64 group_depth = ios->layout->group_depth;
+ u32 U = stripe_unit * group_width;
+
+ u64 T = U * group_depth;
+ u64 S = T * ios->layout->group_count;
+ u64 M = div64_u64(file_offset, S);
+
+ /*
+ G = (L - (M * S)) / T
+ H = (L - (M * S)) % T
+ */
+ u64 LmodU = file_offset - M * S;
+ u32 G = div64_u64(LmodU, T);
+ u64 H = LmodU - G * T;
+
+ u32 N = div_u64(H, U);
+
+ div_u64_rem(file_offset, stripe_unit, &si->unit_off);
+ si->obj_offset = si->unit_off + (N * stripe_unit) +
+ (M * group_depth * stripe_unit);
+
+ /* "H - (N * U)" is just "H % U" so it's bound to u32 */
+ si->dev = (u32)(H - (N * U)) / stripe_unit + G * group_width;
+ si->dev *= ios->layout->mirrors_p1;
+
+ si->group_length = T - H;
+}
+
+static int _add_stripe_unit(struct objio_state *ios, unsigned *cur_pg,
+ unsigned pgbase, struct _objio_per_comp *per_dev, int cur_len,
+ gfp_t gfp_flags)
+{
+ unsigned pg = *cur_pg;
+ struct request_queue *q =
+ osd_request_queue(_io_od(ios, per_dev->dev));
+
+ per_dev->length += cur_len;
+
+ if (per_dev->bio == NULL) {
+ unsigned stripes = ios->layout->num_comps /
+ ios->layout->mirrors_p1;
+ unsigned pages_in_stripe = stripes *
+ (ios->layout->stripe_unit / PAGE_SIZE);
+ unsigned bio_size = (ios->ol_state.nr_pages + pages_in_stripe) /
+ stripes;
+
+ if (BIO_MAX_PAGES_KMALLOC < bio_size)
+ bio_size = BIO_MAX_PAGES_KMALLOC;
+
+ per_dev->bio = bio_kmalloc(gfp_flags, bio_size);
+ if (unlikely(!per_dev->bio)) {
+ dprintk("Faild to allocate BIO size=%u\n", bio_size);
+ return -ENOMEM;
+ }
+ }
+
+ while (cur_len > 0) {
+ unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len);
+ unsigned added_len;
+
+ BUG_ON(ios->ol_state.nr_pages <= pg);
+ cur_len -= pglen;
+
+ added_len = bio_add_pc_page(q, per_dev->bio,
+ ios->ol_state.pages[pg], pglen, pgbase);
+ if (unlikely(pglen != added_len))
+ return -ENOMEM;
+ pgbase = 0;
+ ++pg;
+ }
+ BUG_ON(cur_len);
+
+ *cur_pg = pg;
+ return 0;
+}
+
+static int _prepare_one_group(struct objio_state *ios, u64 length,
+ struct _striping_info *si, unsigned *last_pg,
+ gfp_t gfp_flags)
+{
+ unsigned stripe_unit = ios->layout->stripe_unit;
+ unsigned mirrors_p1 = ios->layout->mirrors_p1;
+ unsigned devs_in_group = ios->layout->group_width * mirrors_p1;
+ unsigned dev = si->dev;
+ unsigned first_dev = dev - (dev % devs_in_group);
+ unsigned max_comp = ios->numdevs ? ios->numdevs - mirrors_p1 : 0;
+ unsigned cur_pg = *last_pg;
+ int ret = 0;
+
+ while (length) {
+ struct _objio_per_comp *per_dev = &ios->per_dev[dev];
+ unsigned cur_len, page_off = 0;
+
+ if (!per_dev->length) {
+ per_dev->dev = dev;
+ if (dev < si->dev) {
+ per_dev->offset = si->obj_offset + stripe_unit -
+ si->unit_off;
+ cur_len = stripe_unit;
+ } else if (dev == si->dev) {
+ per_dev->offset = si->obj_offset;
+ cur_len = stripe_unit - si->unit_off;
+ page_off = si->unit_off & ~PAGE_MASK;
+ BUG_ON(page_off &&
+ (page_off != ios->ol_state.pgbase));
+ } else { /* dev > si->dev */
+ per_dev->offset = si->obj_offset - si->unit_off;
+ cur_len = stripe_unit;
+ }
+
+ if (max_comp < dev)
+ max_comp = dev;
+ } else {
+ cur_len = stripe_unit;
+ }
+ if (cur_len >= length)
+ cur_len = length;
+
+ ret = _add_stripe_unit(ios, &cur_pg, page_off , per_dev,
+ cur_len, gfp_flags);
+ if (unlikely(ret))
+ goto out;
+
+ dev += mirrors_p1;
+ dev = (dev % devs_in_group) + first_dev;
+
+ length -= cur_len;
+ ios->length += cur_len;
+ }
+out:
+ ios->numdevs = max_comp + mirrors_p1;
+ *last_pg = cur_pg;
+ return ret;
+}
+
+static int _io_rw_pagelist(struct objio_state *ios, gfp_t gfp_flags)
+{
+ u64 length = ios->ol_state.count;
+ u64 offset = ios->ol_state.offset;
+ struct _striping_info si;
+ unsigned last_pg = 0;
+ int ret = 0;
+
+ while (length) {
+ _calc_stripe_info(ios, offset, &si);
+
+ if (length < si.group_length)
+ si.group_length = length;
+
+ ret = _prepare_one_group(ios, si.group_length, &si, &last_pg, gfp_flags);
+ if (unlikely(ret))
+ goto out;
+
+ offset += si.group_length;
+ length -= si.group_length;
+ }
+
+out:
+ if (!ios->length)
+ return ret;
+
+ return 0;
+}
+
+static ssize_t _sync_done(struct objio_state *ios)
+{
+ struct completion *waiting = ios->private;
+
+ complete(waiting);
+ return 0;
+}
+
+static void _last_io(struct kref *kref)
+{
+ struct objio_state *ios = container_of(kref, struct objio_state, kref);
+
+ ios->done(ios);
+}
+
+static void _done_io(struct osd_request *or, void *p)
+{
+ struct objio_state *ios = p;
+
+ kref_put(&ios->kref, _last_io);
+}
+
+static ssize_t _io_exec(struct objio_state *ios)
+{
+ DECLARE_COMPLETION_ONSTACK(wait);
+ ssize_t status = 0; /* sync status */
+ unsigned i;
+ objio_done_fn saved_done_fn = ios->done;
+ bool sync = ios->ol_state.sync;
+
+ if (sync) {
+ ios->done = _sync_done;
+ ios->private = &wait;
+ }
+
+ kref_init(&ios->kref);
+
+ for (i = 0; i < ios->numdevs; i++) {
+ struct osd_request *or = ios->per_dev[i].or;
+
+ if (!or)
+ continue;
+
+ kref_get(&ios->kref);
+ osd_execute_request_async(or, _done_io, ios);
+ }
+
+ kref_put(&ios->kref, _last_io);
+
+ if (sync) {
+ wait_for_completion(&wait);
+ status = saved_done_fn(ios);
+ }
+
+ return status;
+}
+
+/*
+ * read
+ */
+static ssize_t _read_done(struct objio_state *ios)
+{
+ ssize_t status;
+ int ret = _io_check(ios, false);
+
+ _io_free(ios);
+
+ if (likely(!ret))
+ status = ios->length;
+ else
+ status = ret;
+
+ objlayout_read_done(&ios->ol_state, status, ios->ol_state.sync);
+ return status;
+}
+
+static int _read_mirrors(struct objio_state *ios, unsigned cur_comp)
+{
+ struct osd_request *or = NULL;
+ struct _objio_per_comp *per_dev = &ios->per_dev[cur_comp];
+ unsigned dev = per_dev->dev;
+ struct pnfs_osd_object_cred *cred =
+ &ios->layout->comps[dev];
+ struct osd_obj_id obj = {
+ .partition = cred->oc_object_id.oid_partition_id,
+ .id = cred->oc_object_id.oid_object_id,
+ };
+ int ret;
+
+ or = osd_start_request(_io_od(ios, dev), GFP_KERNEL);
+ if (unlikely(!or)) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ per_dev->or = or;
+
+ osd_req_read(or, &obj, per_dev->offset, per_dev->bio, per_dev->length);
+
+ ret = osd_finalize_request(or, 0, cred->oc_cap.cred, NULL);
+ if (ret) {
+ dprintk("%s: Faild to osd_finalize_request() => %d\n",
+ __func__, ret);
+ goto err;
+ }
+
+ dprintk("%s:[%d] dev=%d obj=0x%llx start=0x%llx length=0x%lx\n",
+ __func__, cur_comp, dev, obj.id, _LLU(per_dev->offset),
+ per_dev->length);
+
+err:
+ return ret;
+}
+
+static ssize_t _read_exec(struct objio_state *ios)
+{
+ unsigned i;
+ int ret;
+
+ for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
+ if (!ios->per_dev[i].length)
+ continue;
+ ret = _read_mirrors(ios, i);
+ if (unlikely(ret))
+ goto err;
+ }
+
+ ios->done = _read_done;
+ return _io_exec(ios); /* In sync mode exec returns the io status */
+
+err:
+ _io_free(ios);
+ return ret;
+}
+
+ssize_t objio_read_pagelist(struct objlayout_io_state *ol_state)
+{
+ struct objio_state *ios = container_of(ol_state, struct objio_state,
+ ol_state);
+ int ret;
+
+ ret = _io_rw_pagelist(ios, GFP_KERNEL);
+ if (unlikely(ret))
+ return ret;
+
+ return _read_exec(ios);
+}
+
+/*
+ * write
+ */
+static ssize_t _write_done(struct objio_state *ios)
+{
+ ssize_t status;
+ int ret = _io_check(ios, true);
+
+ _io_free(ios);
+
+ if (likely(!ret)) {
+ /* FIXME: should be based on the OSD's persistence model
+ * See OSD2r05 Section 4.13 Data persistence model */
+ ios->ol_state.committed = NFS_FILE_SYNC;
+ status = ios->length;
+ } else {
+ status = ret;
+ }
+
+ objlayout_write_done(&ios->ol_state, status, ios->ol_state.sync);
+ return status;
+}
+
+static int _write_mirrors(struct objio_state *ios, unsigned cur_comp)
+{
+ struct _objio_per_comp *master_dev = &ios->per_dev[cur_comp];
+ unsigned dev = ios->per_dev[cur_comp].dev;
+ unsigned last_comp = cur_comp + ios->layout->mirrors_p1;
+ int ret;
+
+ for (; cur_comp < last_comp; ++cur_comp, ++dev) {
+ struct osd_request *or = NULL;
+ struct pnfs_osd_object_cred *cred =
+ &ios->layout->comps[dev];
+ struct osd_obj_id obj = {
+ .partition = cred->oc_object_id.oid_partition_id,
+ .id = cred->oc_object_id.oid_object_id,
+ };
+ struct _objio_per_comp *per_dev = &ios->per_dev[cur_comp];
+ struct bio *bio;
+
+ or = osd_start_request(_io_od(ios, dev), GFP_NOFS);
+ if (unlikely(!or)) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ per_dev->or = or;
+
+ if (per_dev != master_dev) {
+ bio = bio_kmalloc(GFP_NOFS,
+ master_dev->bio->bi_max_vecs);
+ if (unlikely(!bio)) {
+ dprintk("Faild to allocate BIO size=%u\n",
+ master_dev->bio->bi_max_vecs);
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ __bio_clone(bio, master_dev->bio);
+ bio->bi_bdev = NULL;
+ bio->bi_next = NULL;
+ per_dev->bio = bio;
+ per_dev->dev = dev;
+ per_dev->length = master_dev->length;
+ per_dev->offset = master_dev->offset;
+ } else {
+ bio = master_dev->bio;
+ bio->bi_rw |= REQ_WRITE;
+ }
+
+ osd_req_write(or, &obj, per_dev->offset, bio, per_dev->length);
+
+ ret = osd_finalize_request(or, 0, cred->oc_cap.cred, NULL);
+ if (ret) {
+ dprintk("%s: Faild to osd_finalize_request() => %d\n",
+ __func__, ret);
+ goto err;
+ }
+
+ dprintk("%s:[%d] dev=%d obj=0x%llx start=0x%llx length=0x%lx\n",
+ __func__, cur_comp, dev, obj.id, _LLU(per_dev->offset),
+ per_dev->length);
+ }
+
+err:
+ return ret;
+}
+
+static ssize_t _write_exec(struct objio_state *ios)
+{
+ unsigned i;
+ int ret;
+
+ for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
+ if (!ios->per_dev[i].length)
+ continue;
+ ret = _write_mirrors(ios, i);
+ if (unlikely(ret))
+ goto err;
+ }
+
+ ios->done = _write_done;
+ return _io_exec(ios); /* In sync mode exec returns the io->status */
+
+err:
+ _io_free(ios);
+ return ret;
+}
+
+ssize_t objio_write_pagelist(struct objlayout_io_state *ol_state, bool stable)
+{
+ struct objio_state *ios = container_of(ol_state, struct objio_state,
+ ol_state);
+ int ret;
+
+ /* TODO: ios->stable = stable; */
+ ret = _io_rw_pagelist(ios, GFP_NOFS);
+ if (unlikely(ret))
+ return ret;
+
+ return _write_exec(ios);
+}
+
+/*
+ * objlayout_pg_test(). Called by nfs_can_coalesce_requests()
+ *
+ * return 1 : coalesce page
+ * return 0 : don't coalesce page
+ */
+int
+objlayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
+ struct nfs_page *req)
+{
+ return 1;
+}
static struct pnfs_layoutdriver_type objlayout_type = {
.id = LAYOUT_OSD2_OBJECTS,
@@ -370,6 +971,10 @@
.alloc_lseg = objlayout_alloc_lseg,
.free_lseg = objlayout_free_lseg,
+ .read_pagelist = objlayout_read_pagelist,
+ .write_pagelist = objlayout_write_pagelist,
+ .pg_test = objlayout_pg_test,
+
.free_deviceid_node = objio_free_deviceid_node,
};