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path: root/drivers/staging/lustre/lustre/obdecho/echo.c
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Diffstat (limited to 'drivers/staging/lustre/lustre/obdecho/echo.c')
-rw-r--r--drivers/staging/lustre/lustre/obdecho/echo.c679
1 files changed, 679 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/obdecho/echo.c b/drivers/staging/lustre/lustre/obdecho/echo.c
new file mode 100644
index 000000000000..9e64939af9dc
--- /dev/null
+++ b/drivers/staging/lustre/lustre/obdecho/echo.c
@@ -0,0 +1,679 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program 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 version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2010, 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/obdecho/echo.c
+ *
+ * Author: Peter Braam <braam@clusterfs.com>
+ * Author: Andreas Dilger <adilger@clusterfs.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_ECHO
+
+#include <obd_support.h>
+#include <obd_class.h>
+#include <lustre_debug.h>
+#include <lustre_dlm.h>
+#include <lprocfs_status.h>
+
+#include "echo_internal.h"
+
+/* The echo objid needs to be below 2^32, because regular FID numbers are
+ * limited to 2^32 objects in f_oid for the FID_SEQ_ECHO range. b=23335 */
+#define ECHO_INIT_OID 0x10000000ULL
+#define ECHO_HANDLE_MAGIC 0xabcd0123fedc9876ULL
+
+#define ECHO_PERSISTENT_PAGES (ECHO_PERSISTENT_SIZE >> PAGE_CACHE_SHIFT)
+static struct page *echo_persistent_pages[ECHO_PERSISTENT_PAGES];
+
+enum {
+ LPROC_ECHO_READ_BYTES = 1,
+ LPROC_ECHO_WRITE_BYTES = 2,
+ LPROC_ECHO_LAST = LPROC_ECHO_WRITE_BYTES +1
+};
+
+static int echo_connect(const struct lu_env *env,
+ struct obd_export **exp, struct obd_device *obd,
+ struct obd_uuid *cluuid, struct obd_connect_data *data,
+ void *localdata)
+{
+ struct lustre_handle conn = { 0 };
+ int rc;
+
+ data->ocd_connect_flags &= ECHO_CONNECT_SUPPORTED;
+ rc = class_connect(&conn, obd, cluuid);
+ if (rc) {
+ CERROR("can't connect %d\n", rc);
+ return rc;
+ }
+ *exp = class_conn2export(&conn);
+
+ return 0;
+}
+
+static int echo_disconnect(struct obd_export *exp)
+{
+ LASSERT (exp != NULL);
+
+ return server_disconnect_export(exp);
+}
+
+static int echo_init_export(struct obd_export *exp)
+{
+ return ldlm_init_export(exp);
+}
+
+static int echo_destroy_export(struct obd_export *exp)
+{
+ ENTRY;
+
+ target_destroy_export(exp);
+ ldlm_destroy_export(exp);
+
+ RETURN(0);
+}
+
+ static __u64 echo_next_id(struct obd_device *obddev)
+{
+ obd_id id;
+
+ spin_lock(&obddev->u.echo.eo_lock);
+ id = ++obddev->u.echo.eo_lastino;
+ spin_unlock(&obddev->u.echo.eo_lock);
+
+ return id;
+}
+
+static int echo_create(const struct lu_env *env, struct obd_export *exp,
+ struct obdo *oa, struct lov_stripe_md **ea,
+ struct obd_trans_info *oti)
+{
+ struct obd_device *obd = class_exp2obd(exp);
+
+ if (!obd) {
+ CERROR("invalid client cookie "LPX64"\n",
+ exp->exp_handle.h_cookie);
+ return -EINVAL;
+ }
+
+ if (!(oa->o_mode && S_IFMT)) {
+ CERROR("echo obd: no type!\n");
+ return -ENOENT;
+ }
+
+ if (!(oa->o_valid & OBD_MD_FLTYPE)) {
+ CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
+ return -EINVAL;
+ }
+
+ ostid_set_seq_echo(&oa->o_oi);
+ ostid_set_id(&oa->o_oi, echo_next_id(obd));
+ oa->o_valid = OBD_MD_FLID;
+
+ return 0;
+}
+
+static int echo_destroy(const struct lu_env *env, struct obd_export *exp,
+ struct obdo *oa, struct lov_stripe_md *ea,
+ struct obd_trans_info *oti, struct obd_export *md_exp,
+ void *capa)
+{
+ struct obd_device *obd = class_exp2obd(exp);
+
+ ENTRY;
+ if (!obd) {
+ CERROR("invalid client cookie "LPX64"\n",
+ exp->exp_handle.h_cookie);
+ RETURN(-EINVAL);
+ }
+
+ if (!(oa->o_valid & OBD_MD_FLID)) {
+ CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
+ RETURN(-EINVAL);
+ }
+
+ if (ostid_id(&oa->o_oi) > obd->u.echo.eo_lastino ||
+ ostid_id(&oa->o_oi) < ECHO_INIT_OID) {
+ CERROR("bad destroy objid: "DOSTID"\n", POSTID(&oa->o_oi));
+ RETURN(-EINVAL);
+ }
+
+ RETURN(0);
+}
+
+static int echo_getattr(const struct lu_env *env, struct obd_export *exp,
+ struct obd_info *oinfo)
+{
+ struct obd_device *obd = class_exp2obd(exp);
+ obd_id id = ostid_id(&oinfo->oi_oa->o_oi);
+
+ ENTRY;
+ if (!obd) {
+ CERROR("invalid client cookie "LPX64"\n",
+ exp->exp_handle.h_cookie);
+ RETURN(-EINVAL);
+ }
+
+ if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
+ CERROR("obdo missing FLID valid flag: "LPX64"\n",
+ oinfo->oi_oa->o_valid);
+ RETURN(-EINVAL);
+ }
+
+ obdo_cpy_md(oinfo->oi_oa, &obd->u.echo.eo_oa, oinfo->oi_oa->o_valid);
+ ostid_set_seq_echo(&oinfo->oi_oa->o_oi);
+ ostid_set_id(&oinfo->oi_oa->o_oi, id);
+
+ RETURN(0);
+}
+
+static int echo_setattr(const struct lu_env *env, struct obd_export *exp,
+ struct obd_info *oinfo, struct obd_trans_info *oti)
+{
+ struct obd_device *obd = class_exp2obd(exp);
+
+ ENTRY;
+ if (!obd) {
+ CERROR("invalid client cookie "LPX64"\n",
+ exp->exp_handle.h_cookie);
+ RETURN(-EINVAL);
+ }
+
+ if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
+ CERROR("obdo missing FLID valid flag: "LPX64"\n",
+ oinfo->oi_oa->o_valid);
+ RETURN(-EINVAL);
+ }
+
+ memcpy(&obd->u.echo.eo_oa, oinfo->oi_oa, sizeof(*oinfo->oi_oa));
+
+ if (ostid_id(&oinfo->oi_oa->o_oi) & 4) {
+ /* Save lock to force ACKed reply */
+ ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
+ oti->oti_ack_locks[0].mode = LCK_NL;
+ oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
+ }
+
+ RETURN(0);
+}
+
+static void
+echo_page_debug_setup(struct page *page, int rw, obd_id id,
+ __u64 offset, int len)
+{
+ int page_offset = offset & ~CFS_PAGE_MASK;
+ char *addr = ((char *)kmap(page)) + page_offset;
+
+ if (len % OBD_ECHO_BLOCK_SIZE != 0)
+ CERROR("Unexpected block size %d\n", len);
+
+ while (len > 0) {
+ if (rw & OBD_BRW_READ)
+ block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
+ offset, id);
+ else
+ block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
+ 0xecc0ecc0ecc0ecc0ULL,
+ 0xecc0ecc0ecc0ecc0ULL);
+
+ addr += OBD_ECHO_BLOCK_SIZE;
+ offset += OBD_ECHO_BLOCK_SIZE;
+ len -= OBD_ECHO_BLOCK_SIZE;
+ }
+
+ kunmap(page);
+}
+
+static int
+echo_page_debug_check(struct page *page, obd_id id,
+ __u64 offset, int len)
+{
+ int page_offset = offset & ~CFS_PAGE_MASK;
+ char *addr = ((char *)kmap(page)) + page_offset;
+ int rc = 0;
+ int rc2;
+
+ if (len % OBD_ECHO_BLOCK_SIZE != 0)
+ CERROR("Unexpected block size %d\n", len);
+
+ while (len > 0) {
+ rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
+ offset, id);
+
+ if (rc2 != 0 && rc == 0)
+ rc = rc2;
+
+ addr += OBD_ECHO_BLOCK_SIZE;
+ offset += OBD_ECHO_BLOCK_SIZE;
+ len -= OBD_ECHO_BLOCK_SIZE;
+ }
+
+ kunmap(page);
+
+ return (rc);
+}
+
+/* This allows us to verify that desc_private is passed unmolested */
+#define DESC_PRIV 0x10293847
+
+static int echo_map_nb_to_lb(struct obdo *oa, struct obd_ioobj *obj,
+ struct niobuf_remote *nb, int *pages,
+ struct niobuf_local *lb, int cmd, int *left)
+{
+ int gfp_mask = (ostid_id(&obj->ioo_oid) & 1) ?
+ GFP_HIGHUSER : GFP_IOFS;
+ int ispersistent = ostid_id(&obj->ioo_oid) == ECHO_PERSISTENT_OBJID;
+ int debug_setup = (!ispersistent &&
+ (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
+ (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
+ struct niobuf_local *res = lb;
+ obd_off offset = nb->offset;
+ int len = nb->len;
+
+ while (len > 0) {
+ int plen = PAGE_CACHE_SIZE - (offset & (PAGE_CACHE_SIZE-1));
+ if (len < plen)
+ plen = len;
+
+ /* check for local buf overflow */
+ if (*left == 0)
+ return -EINVAL;
+
+ res->lnb_file_offset = offset;
+ res->len = plen;
+ LASSERT((res->lnb_file_offset & ~CFS_PAGE_MASK) + res->len <=
+ PAGE_CACHE_SIZE);
+
+ if (ispersistent &&
+ ((res->lnb_file_offset >> PAGE_CACHE_SHIFT) <
+ ECHO_PERSISTENT_PAGES)) {
+ res->page =
+ echo_persistent_pages[res->lnb_file_offset >>
+ PAGE_CACHE_SHIFT];
+ /* Take extra ref so __free_pages() can be called OK */
+ get_page (res->page);
+ } else {
+ OBD_PAGE_ALLOC(res->page, gfp_mask);
+ if (res->page == NULL) {
+ CERROR("can't get page for id " DOSTID"\n",
+ POSTID(&obj->ioo_oid));
+ return -ENOMEM;
+ }
+ }
+
+ CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
+ res->page, res->lnb_file_offset, res->len);
+
+ if (cmd & OBD_BRW_READ)
+ res->rc = res->len;
+
+ if (debug_setup)
+ echo_page_debug_setup(res->page, cmd,
+ ostid_id(&obj->ioo_oid),
+ res->lnb_file_offset, res->len);
+
+ offset += plen;
+ len -= plen;
+ res++;
+
+ (*left)--;
+ (*pages)++;
+ }
+
+ return 0;
+}
+
+static int echo_finalize_lb(struct obdo *oa, struct obd_ioobj *obj,
+ struct niobuf_remote *rb, int *pgs,
+ struct niobuf_local *lb, int verify)
+{
+ struct niobuf_local *res = lb;
+ obd_off start = rb->offset >> PAGE_CACHE_SHIFT;
+ obd_off end = (rb->offset + rb->len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ int count = (int)(end - start);
+ int rc = 0;
+ int i;
+
+ for (i = 0; i < count; i++, (*pgs) ++, res++) {
+ struct page *page = res->page;
+ void *addr;
+
+ if (page == NULL) {
+ CERROR("null page objid "LPU64":%p, buf %d/%d\n",
+ ostid_id(&obj->ioo_oid), page, i,
+ obj->ioo_bufcnt);
+ return -EFAULT;
+ }
+
+ addr = kmap(page);
+
+ CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
+ res->page, addr, res->lnb_file_offset);
+
+ if (verify) {
+ int vrc = echo_page_debug_check(page,
+ ostid_id(&obj->ioo_oid),
+ res->lnb_file_offset,
+ res->len);
+ /* check all the pages always */
+ if (vrc != 0 && rc == 0)
+ rc = vrc;
+ }
+
+ kunmap(page);
+ /* NB see comment above regarding persistent pages */
+ OBD_PAGE_FREE(page);
+ }
+
+ return rc;
+}
+
+static int echo_preprw(const struct lu_env *env, int cmd,
+ struct obd_export *export, struct obdo *oa,
+ int objcount, struct obd_ioobj *obj,
+ struct niobuf_remote *nb, int *pages,
+ struct niobuf_local *res, struct obd_trans_info *oti,
+ struct lustre_capa *unused)
+{
+ struct obd_device *obd;
+ int tot_bytes = 0;
+ int rc = 0;
+ int i, left;
+ ENTRY;
+
+ obd = export->exp_obd;
+ if (obd == NULL)
+ RETURN(-EINVAL);
+
+ /* Temp fix to stop falling foul of osc_announce_cached() */
+ oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
+
+ memset(res, 0, sizeof(*res) * *pages);
+
+ CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
+ cmd == OBD_BRW_READ ? "reading" : "writing", objcount, *pages);
+
+ if (oti)
+ oti->oti_handle = (void *)DESC_PRIV;
+
+ left = *pages;
+ *pages = 0;
+
+ for (i = 0; i < objcount; i++, obj++) {
+ int j;
+
+ for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++) {
+
+ rc = echo_map_nb_to_lb(oa, obj, nb, pages,
+ res + *pages, cmd, &left);
+ if (rc)
+ GOTO(preprw_cleanup, rc);
+
+ tot_bytes += nb->len;
+ }
+ }
+
+ atomic_add(*pages, &obd->u.echo.eo_prep);
+
+ if (cmd & OBD_BRW_READ)
+ lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
+ tot_bytes);
+ else
+ lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
+ tot_bytes);
+
+ CDEBUG(D_PAGE, "%d pages allocated after prep\n",
+ atomic_read(&obd->u.echo.eo_prep));
+
+ RETURN(0);
+
+preprw_cleanup:
+ /* It is possible that we would rather handle errors by allow
+ * any already-set-up pages to complete, rather than tearing them
+ * all down again. I believe that this is what the in-kernel
+ * prep/commit operations do.
+ */
+ CERROR("cleaning up %u pages (%d obdos)\n", *pages, objcount);
+ for (i = 0; i < *pages; i++) {
+ kunmap(res[i].page);
+ /* NB if this is a persistent page, __free_pages will just
+ * lose the extra ref gained above */
+ OBD_PAGE_FREE(res[i].page);
+ res[i].page = NULL;
+ atomic_dec(&obd->u.echo.eo_prep);
+ }
+
+ return rc;
+}
+
+static int echo_commitrw(const struct lu_env *env, int cmd,
+ struct obd_export *export, struct obdo *oa,
+ int objcount, struct obd_ioobj *obj,
+ struct niobuf_remote *rb, int niocount,
+ struct niobuf_local *res, struct obd_trans_info *oti,
+ int rc)
+{
+ struct obd_device *obd;
+ int pgs = 0;
+ int i;
+ ENTRY;
+
+ obd = export->exp_obd;
+ if (obd == NULL)
+ RETURN(-EINVAL);
+
+ if (rc)
+ GOTO(commitrw_cleanup, rc);
+
+ if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
+ CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
+ objcount, niocount);
+ } else {
+ CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
+ objcount, niocount);
+ }
+
+ if (niocount && res == NULL) {
+ CERROR("NULL res niobuf with niocount %d\n", niocount);
+ RETURN(-EINVAL);
+ }
+
+ LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
+
+ for (i = 0; i < objcount; i++, obj++) {
+ int verify = (rc == 0 &&
+ ostid_id(&obj->ioo_oid) != ECHO_PERSISTENT_OBJID &&
+ (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
+ (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
+ int j;
+
+ for (j = 0 ; j < obj->ioo_bufcnt ; j++, rb++) {
+ int vrc = echo_finalize_lb(oa, obj, rb, &pgs, &res[pgs],
+ verify);
+ if (vrc == 0)
+ continue;
+
+ if (vrc == -EFAULT)
+ GOTO(commitrw_cleanup, rc = vrc);
+
+ if (rc == 0)
+ rc = vrc;
+ }
+
+ }
+
+ atomic_sub(pgs, &obd->u.echo.eo_prep);
+
+ CDEBUG(D_PAGE, "%d pages remain after commit\n",
+ atomic_read(&obd->u.echo.eo_prep));
+ RETURN(rc);
+
+commitrw_cleanup:
+ atomic_sub(pgs, &obd->u.echo.eo_prep);
+
+ CERROR("cleaning up %d pages (%d obdos)\n",
+ niocount - pgs - 1, objcount);
+
+ while (pgs < niocount) {
+ struct page *page = res[pgs++].page;
+
+ if (page == NULL)
+ continue;
+
+ /* NB see comment above regarding persistent pages */
+ OBD_PAGE_FREE(page);
+ atomic_dec(&obd->u.echo.eo_prep);
+ }
+ return rc;
+}
+
+static int echo_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
+{
+ struct lprocfs_static_vars lvars;
+ int rc;
+ __u64 lock_flags = 0;
+ struct ldlm_res_id res_id = {.name = {1}};
+ char ns_name[48];
+ ENTRY;
+
+ obd->u.echo.eo_obt.obt_magic = OBT_MAGIC;
+ spin_lock_init(&obd->u.echo.eo_lock);
+ obd->u.echo.eo_lastino = ECHO_INIT_OID;
+
+ sprintf(ns_name, "echotgt-%s", obd->obd_uuid.uuid);
+ obd->obd_namespace = ldlm_namespace_new(obd, ns_name,
+ LDLM_NAMESPACE_SERVER,
+ LDLM_NAMESPACE_MODEST,
+ LDLM_NS_TYPE_OST);
+ if (obd->obd_namespace == NULL) {
+ LBUG();
+ RETURN(-ENOMEM);
+ }
+
+ rc = ldlm_cli_enqueue_local(obd->obd_namespace, &res_id, LDLM_PLAIN,
+ NULL, LCK_NL, &lock_flags, NULL,
+ ldlm_completion_ast, NULL, NULL, 0,
+ LVB_T_NONE, NULL, &obd->u.echo.eo_nl_lock);
+ LASSERT (rc == ELDLM_OK);
+
+ lprocfs_echo_init_vars(&lvars);
+ if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0 &&
+ lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST) == 0) {
+ lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
+ LPROCFS_CNTR_AVGMINMAX,
+ "read_bytes", "bytes");
+ lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
+ LPROCFS_CNTR_AVGMINMAX,
+ "write_bytes", "bytes");
+ }
+
+ ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
+ "echo_ldlm_cb_client", &obd->obd_ldlm_client);
+ RETURN(0);
+}
+
+static int echo_cleanup(struct obd_device *obd)
+{
+ int leaked;
+ ENTRY;
+
+ lprocfs_obd_cleanup(obd);
+ lprocfs_free_obd_stats(obd);
+
+ ldlm_lock_decref(&obd->u.echo.eo_nl_lock, LCK_NL);
+
+ /* XXX Bug 3413; wait for a bit to ensure the BL callback has
+ * happened before calling ldlm_namespace_free() */
+ schedule_timeout_and_set_state(TASK_UNINTERRUPTIBLE, cfs_time_seconds(1));
+
+ ldlm_namespace_free(obd->obd_namespace, NULL, obd->obd_force);
+ obd->obd_namespace = NULL;
+
+ leaked = atomic_read(&obd->u.echo.eo_prep);
+ if (leaked != 0)
+ CERROR("%d prep/commitrw pages leaked\n", leaked);
+
+ RETURN(0);
+}
+
+struct obd_ops echo_obd_ops = {
+ .o_owner = THIS_MODULE,
+ .o_connect = echo_connect,
+ .o_disconnect = echo_disconnect,
+ .o_init_export = echo_init_export,
+ .o_destroy_export = echo_destroy_export,
+ .o_create = echo_create,
+ .o_destroy = echo_destroy,
+ .o_getattr = echo_getattr,
+ .o_setattr = echo_setattr,
+ .o_preprw = echo_preprw,
+ .o_commitrw = echo_commitrw,
+ .o_setup = echo_setup,
+ .o_cleanup = echo_cleanup
+};
+
+void echo_persistent_pages_fini(void)
+{
+ int i;
+
+ for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
+ if (echo_persistent_pages[i] != NULL) {
+ OBD_PAGE_FREE(echo_persistent_pages[i]);
+ echo_persistent_pages[i] = NULL;
+ }
+}
+
+int echo_persistent_pages_init(void)
+{
+ struct page *pg;
+ int i;
+
+ for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
+ int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
+ GFP_IOFS : GFP_HIGHUSER;
+
+ OBD_PAGE_ALLOC(pg, gfp_mask);
+ if (pg == NULL) {
+ echo_persistent_pages_fini ();
+ return (-ENOMEM);
+ }
+
+ memset (kmap (pg), 0, PAGE_CACHE_SIZE);
+ kunmap (pg);
+
+ echo_persistent_pages[i] = pg;
+ }
+
+ return (0);
+}
generated by cgit v1.2.3 (git 2.0.4) at 2024-06-03 23:28:03 +0000