summaryrefslogtreecommitdiff
path: root/fs/exofs/ios.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/exofs/ios.c')
-rw-r--r--fs/exofs/ios.c822
1 files changed, 822 insertions, 0 deletions
diff --git a/fs/exofs/ios.c b/fs/exofs/ios.c
new file mode 100644
index 000000000000..5293bc411d17
--- /dev/null
+++ b/fs/exofs/ios.c
@@ -0,0 +1,822 @@
+/*
+ * 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 <asm/div64.h>
+
+#include "exofs.h"
+
+#define EXOFS_DBGMSG2(M...) do {} while (0)
+/* #define EXOFS_DBGMSG2 EXOFS_DBGMSG */
+
+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_layout *layout,
+ struct exofs_io_state **pios)
+{
+ struct exofs_io_state *ios;
+
+ /*TODO: Maybe use kmem_cach per sbi of size
+ * exofs_io_state_size(layout->s_numdevs)
+ */
+ ios = kzalloc(exofs_io_state_size(layout->s_numdevs), GFP_KERNEL);
+ if (unlikely(!ios)) {
+ EXOFS_DBGMSG("Faild kzalloc bytes=%d\n",
+ exofs_io_state_size(layout->s_numdevs));
+ *pios = NULL;
+ return -ENOMEM;
+ }
+
+ ios->layout = layout;
+ ios->obj.partition = layout->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);
+ }
+}
+
+unsigned exofs_layout_od_id(struct exofs_layout *layout,
+ osd_id obj_no, unsigned layout_index)
+{
+/* switch (layout->lay_func) {
+ case LAYOUT_MOVING_WINDOW:
+ {*/
+ unsigned dev_mod = obj_no;
+
+ return (layout_index + dev_mod * layout->mirrors_p1) %
+ layout->s_numdevs;
+/* }
+ case LAYOUT_FUNC_IMPLICT:
+ return layout->devs[layout_index];
+ }*/
+}
+
+static inline struct osd_dev *exofs_ios_od(struct exofs_io_state *ios,
+ unsigned layout_index)
+{
+ return ios->layout->s_ods[
+ exofs_layout_od_id(ios->layout, ios->obj.id, layout_index)];
+}
+
+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;
+}
+
+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);
+ }
+}
+
+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;
+ struct osd_request *or = ios->per_dev[i].or;
+ int ret;
+
+ if (unlikely(!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 */
+ _clear_bio(ios->per_dev[i].bio);
+ EXOFS_DBGMSG("start read offset passed end of file "
+ "offset=0x%llx, length=0x%llx\n",
+ _LLU(ios->per_dev[i].offset),
+ _LLU(ios->per_dev[i].length));
+
+ continue; /* we recovered */
+ }
+
+ 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;
+}
+
+/*
+ * L - logical offset into the file
+ *
+ * U - The number of bytes in a stripe within a group
+ *
+ * U = stripe_unit * group_width
+ *
+ * T - The number of bytes striped within a group of component objects
+ * (before advancing to the next group)
+ *
+ * T = stripe_unit * group_width * group_depth
+ *
+ * S - The number of bytes striped across all component objects
+ * before the pattern repeats
+ *
+ * S = stripe_unit * group_width * group_depth * group_count
+ *
+ * M - The "major" (i.e., across all components) stripe number
+ *
+ * M = L / S
+ *
+ * G - Counts the groups from the beginning of the major stripe
+ *
+ * G = (L - (M * S)) / T [or (L % S) / T]
+ *
+ * H - The byte offset within the group
+ *
+ * H = (L - (M * S)) % T [or (L % S) % T]
+ *
+ * N - The "minor" (i.e., across the group) stripe number
+ *
+ * N = H / U
+ *
+ * C - The component index coresponding to L
+ *
+ * C = (H - (N * U)) / stripe_unit + G * group_width
+ * [or (L % U) / stripe_unit + G * group_width]
+ *
+ * O - The component offset coresponding to L
+ *
+ * O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit
+ */
+struct _striping_info {
+ u64 obj_offset;
+ u64 group_length;
+ u64 total_group_length;
+ u64 Major;
+ unsigned dev;
+ unsigned unit_off;
+};
+
+static void _calc_stripe_info(struct exofs_io_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 LmodS = file_offset - M * S;
+ u32 G = div64_u64(LmodS, T);
+ u64 H = LmodS - G * T;
+
+ u32 N = div_u64(H, U);
+
+ /* "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;
+
+ div_u64_rem(file_offset, stripe_unit, &si->unit_off);
+
+ si->obj_offset = si->unit_off + (N * stripe_unit) +
+ (M * group_depth * stripe_unit);
+
+ si->group_length = T - H;
+ si->total_group_length = T;
+ si->Major = M;
+}
+
+static int _add_stripe_unit(struct exofs_io_state *ios, unsigned *cur_pg,
+ unsigned pgbase, struct exofs_per_dev_state *per_dev,
+ int cur_len)
+{
+ unsigned pg = *cur_pg;
+ struct request_queue *q =
+ osd_request_queue(exofs_ios_od(ios, per_dev->dev));
+
+ per_dev->length += cur_len;
+
+ if (per_dev->bio == NULL) {
+ unsigned pages_in_stripe = ios->layout->group_width *
+ (ios->layout->stripe_unit / PAGE_SIZE);
+ unsigned bio_size = (ios->nr_pages + pages_in_stripe) /
+ ios->layout->group_width;
+
+ per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size);
+ if (unlikely(!per_dev->bio)) {
+ EXOFS_DBGMSG("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->nr_pages <= pg);
+ cur_len -= pglen;
+
+ added_len = bio_add_pc_page(q, per_dev->bio, ios->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 exofs_io_state *ios, u64 length,
+ struct _striping_info *si, unsigned first_comp)
+{
+ 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 comp = first_comp + (dev - first_dev);
+ unsigned max_comp = ios->numdevs ? ios->numdevs - mirrors_p1 : 0;
+ unsigned cur_pg = ios->pages_consumed;
+ int ret = 0;
+
+ while (length) {
+ struct exofs_per_dev_state *per_dev = &ios->per_dev[comp];
+ 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->pgbase));
+ } else { /* dev > si->dev */
+ per_dev->offset = si->obj_offset - si->unit_off;
+ cur_len = stripe_unit;
+ }
+
+ if (max_comp < comp)
+ max_comp = comp;
+
+ dev += mirrors_p1;
+ dev = (dev % devs_in_group) + first_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);
+ if (unlikely(ret))
+ goto out;
+
+ comp += mirrors_p1;
+ comp = (comp % devs_in_group) + first_comp;
+
+ length -= cur_len;
+ }
+out:
+ ios->numdevs = max_comp + mirrors_p1;
+ ios->pages_consumed = cur_pg;
+ return ret;
+}
+
+static int _prepare_for_striping(struct exofs_io_state *ios)
+{
+ u64 length = ios->length;
+ struct _striping_info si;
+ unsigned devs_in_group = ios->layout->group_width *
+ ios->layout->mirrors_p1;
+ unsigned first_comp = 0;
+ int ret = 0;
+
+ _calc_stripe_info(ios, ios->offset, &si);
+
+ if (!ios->pages) {
+ if (ios->kern_buff) {
+ struct exofs_per_dev_state *per_dev = &ios->per_dev[0];
+
+ per_dev->offset = si.obj_offset;
+ per_dev->dev = si.dev;
+
+ /* no cross device without page array */
+ BUG_ON((ios->layout->group_width > 1) &&
+ (si.unit_off + ios->length >
+ ios->layout->stripe_unit));
+ }
+ ios->numdevs = ios->layout->mirrors_p1;
+ return 0;
+ }
+
+ while (length) {
+ if (length < si.group_length)
+ si.group_length = length;
+
+ ret = _prepare_one_group(ios, si.group_length, &si, first_comp);
+ if (unlikely(ret))
+ goto out;
+
+ length -= si.group_length;
+
+ si.group_length = si.total_group_length;
+ si.unit_off = 0;
+ ++si.Major;
+ si.obj_offset = si.Major * ios->layout->stripe_unit *
+ ios->layout->group_depth;
+
+ si.dev = (si.dev - (si.dev % devs_in_group)) + devs_in_group;
+ si.dev %= ios->layout->s_numdevs;
+
+ first_comp += devs_in_group;
+ first_comp %= ios->layout->s_numdevs;
+ }
+
+out:
+ return ret;
+}
+
+int exofs_sbi_create(struct exofs_io_state *ios)
+{
+ int i, ret;
+
+ for (i = 0; i < ios->layout->s_numdevs; i++) {
+ struct osd_request *or;
+
+ or = osd_start_request(exofs_ios_od(ios, 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->layout->s_numdevs; i++) {
+ struct osd_request *or;
+
+ or = osd_start_request(exofs_ios_od(ios, 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;
+}
+
+static int _sbi_write_mirror(struct exofs_io_state *ios, int cur_comp)
+{
+ struct exofs_per_dev_state *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 = 0;
+
+ if (ios->pages && !master_dev->length)
+ return 0; /* Just an empty slot */
+
+ for (; cur_comp < last_comp; ++cur_comp, ++dev) {
+ struct exofs_per_dev_state *per_dev = &ios->per_dev[cur_comp];
+ struct osd_request *or;
+
+ or = osd_start_request(exofs_ios_od(ios, dev), GFP_KERNEL);
+ if (unlikely(!or)) {
+ EXOFS_ERR("%s: osd_start_request failed\n", __func__);
+ ret = -ENOMEM;
+ goto out;
+ }
+ per_dev->or = or;
+ per_dev->offset = master_dev->offset;
+
+ if (ios->pages) {
+ struct bio *bio;
+
+ if (per_dev != master_dev) {
+ bio = bio_kmalloc(GFP_KERNEL,
+ master_dev->bio->bi_max_vecs);
+ if (unlikely(!bio)) {
+ EXOFS_DBGMSG(
+ "Faild to allocate BIO size=%u\n",
+ master_dev->bio->bi_max_vecs);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ __bio_clone(bio, master_dev->bio);
+ bio->bi_bdev = NULL;
+ bio->bi_next = NULL;
+ per_dev->length = master_dev->length;
+ per_dev->bio = bio;
+ per_dev->dev = dev;
+ } else {
+ bio = master_dev->bio;
+ /* FIXME: bio_set_dir() */
+ bio->bi_rw |= (1 << BIO_RW);
+ }
+
+ osd_req_write(or, &ios->obj, per_dev->offset, bio,
+ per_dev->length);
+ EXOFS_DBGMSG("write(0x%llx) offset=0x%llx "
+ "length=0x%llx dev=%d\n",
+ _LLU(ios->obj.id), _LLU(per_dev->offset),
+ _LLU(per_dev->length), dev);
+ } else if (ios->kern_buff) {
+ ret = osd_req_write_kern(or, &ios->obj, per_dev->offset,
+ ios->kern_buff, ios->length);
+ if (unlikely(ret))
+ goto out;
+ EXOFS_DBGMSG2("write_kern(0x%llx) offset=0x%llx "
+ "length=0x%llx dev=%d\n",
+ _LLU(ios->obj.id), _LLU(per_dev->offset),
+ _LLU(ios->length), dev);
+ } else {
+ osd_req_set_attributes(or, &ios->obj);
+ EXOFS_DBGMSG2("obj(0x%llx) set_attributes=%d dev=%d\n",
+ _LLU(ios->obj.id), ios->out_attr_len, dev);
+ }
+
+ 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);
+ }
+
+out:
+ return ret;
+}
+
+int exofs_sbi_write(struct exofs_io_state *ios)
+{
+ int i;
+ int ret;
+
+ ret = _prepare_for_striping(ios);
+ if (unlikely(ret))
+ return ret;
+
+ for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
+ ret = _sbi_write_mirror(ios, i);
+ if (unlikely(ret))
+ return ret;
+ }
+
+ ret = exofs_io_execute(ios);
+ return ret;
+}
+
+static int _sbi_read_mirror(struct exofs_io_state *ios, unsigned cur_comp)
+{
+ struct osd_request *or;
+ struct exofs_per_dev_state *per_dev = &ios->per_dev[cur_comp];
+ unsigned first_dev = (unsigned)ios->obj.id;
+
+ if (ios->pages && !per_dev->length)
+ return 0; /* Just an empty slot */
+
+ first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
+ or = osd_start_request(exofs_ios_od(ios, first_dev), GFP_KERNEL);
+ if (unlikely(!or)) {
+ EXOFS_ERR("%s: osd_start_request failed\n", __func__);
+ return -ENOMEM;
+ }
+ per_dev->or = or;
+
+ if (ios->pages) {
+ osd_req_read(or, &ios->obj, per_dev->offset,
+ per_dev->bio, per_dev->length);
+ EXOFS_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx"
+ " dev=%d\n", _LLU(ios->obj.id),
+ _LLU(per_dev->offset), _LLU(per_dev->length),
+ first_dev);
+ } else if (ios->kern_buff) {
+ int ret = osd_req_read_kern(or, &ios->obj, per_dev->offset,
+ ios->kern_buff, ios->length);
+ EXOFS_DBGMSG2("read_kern(0x%llx) offset=0x%llx "
+ "length=0x%llx dev=%d ret=>%d\n",
+ _LLU(ios->obj.id), _LLU(per_dev->offset),
+ _LLU(ios->length), first_dev, ret);
+ if (unlikely(ret))
+ return ret;
+ } else {
+ osd_req_get_attributes(or, &ios->obj);
+ EXOFS_DBGMSG2("obj(0x%llx) get_attributes=%d dev=%d\n",
+ _LLU(ios->obj.id), ios->in_attr_len, first_dev);
+ }
+ 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);
+
+ return 0;
+}
+
+int exofs_sbi_read(struct exofs_io_state *ios)
+{
+ int i;
+ int ret;
+
+ ret = _prepare_for_striping(ios);
+ if (unlikely(ret))
+ return ret;
+
+ for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
+ ret = _sbi_read_mirror(ios, i);
+ if (unlikely(ret))
+ return ret;
+ }
+
+ ret = exofs_io_execute(ios);
+ 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;
+}
+
+static int _truncate_mirrors(struct exofs_io_state *ios, unsigned cur_comp,
+ struct osd_attr *attr)
+{
+ int last_comp = cur_comp + ios->layout->mirrors_p1;
+
+ for (; cur_comp < last_comp; ++cur_comp) {
+ struct exofs_per_dev_state *per_dev = &ios->per_dev[cur_comp];
+ struct osd_request *or;
+
+ or = osd_start_request(exofs_ios_od(ios, cur_comp), GFP_KERNEL);
+ if (unlikely(!or)) {
+ EXOFS_ERR("%s: osd_start_request failed\n", __func__);
+ return -ENOMEM;
+ }
+ per_dev->or = or;
+
+ osd_req_set_attributes(or, &ios->obj);
+ osd_req_add_set_attr_list(or, attr, 1);
+ }
+
+ return 0;
+}
+
+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 exofs_trunc_attr {
+ struct osd_attr attr;
+ __be64 newsize;
+ } *size_attrs;
+ struct _striping_info si;
+ int i, ret;
+
+ ret = exofs_get_io_state(&sbi->layout, &ios);
+ if (unlikely(ret))
+ return ret;
+
+ size_attrs = kcalloc(ios->layout->group_width, sizeof(*size_attrs),
+ GFP_KERNEL);
+ if (unlikely(!size_attrs)) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ios->obj.id = exofs_oi_objno(oi);
+ ios->cred = oi->i_cred;
+
+ ios->numdevs = ios->layout->s_numdevs;
+ _calc_stripe_info(ios, size, &si);
+
+ for (i = 0; i < ios->layout->group_width; ++i) {
+ struct exofs_trunc_attr *size_attr = &size_attrs[i];
+ u64 obj_size;
+
+ if (i < si.dev)
+ obj_size = si.obj_offset +
+ ios->layout->stripe_unit - si.unit_off;
+ else if (i == si.dev)
+ obj_size = si.obj_offset;
+ else /* i > si.dev */
+ obj_size = si.obj_offset - si.unit_off;
+
+ size_attr->newsize = cpu_to_be64(obj_size);
+ size_attr->attr = g_attr_logical_length;
+ size_attr->attr.val_ptr = &size_attr->newsize;
+
+ ret = _truncate_mirrors(ios, i * ios->layout->mirrors_p1,
+ &size_attr->attr);
+ if (unlikely(ret))
+ goto out;
+ }
+ ret = exofs_io_execute(ios);
+
+out:
+ kfree(size_attrs);
+ exofs_put_io_state(ios);
+ return ret;
+}