1 files changed, 546 insertions, 0 deletions

diff --git a/drivers/staging/lustre/lustre/llite/vvp_dev.c b/drivers/staging/lustre/lustre/llite/vvp_dev.c
new file mode 100644
index 000000000000..9254b990d31c
--- /dev/null
+++ b/drivers/staging/lustre/lustre/llite/vvp_dev.c
@@ -0,0 +1,546 @@
+/*
+ * 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) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * cl_device and cl_device_type implementation for VVP layer.
+ *
+ *   Author: Nikita Danilov <nikita.danilov@sun.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_LLITE
+
+
+#include <obd.h>
+#include <lustre_lite.h>
+
+#include "vvp_internal.h"
+
+/*****************************************************************************
+ *
+ * Vvp device and device type functions.
+ *
+ */
+
+/*
+ * vvp_ prefix stands for "Vfs Vm Posix". It corresponds to historical
+ * "llite_" (var. "ll_") prefix.
+ */
+
+struct kmem_cache *vvp_thread_kmem;
+static struct kmem_cache *vvp_session_kmem;
+static struct lu_kmem_descr vvp_caches[] = {
+	{
+		.ckd_cache = &vvp_thread_kmem,
+		.ckd_name  = "vvp_thread_kmem",
+		.ckd_size  = sizeof (struct vvp_thread_info),
+	},
+	{
+		.ckd_cache = &vvp_session_kmem,
+		.ckd_name  = "vvp_session_kmem",
+		.ckd_size  = sizeof (struct vvp_session)
+	},
+	{
+		.ckd_cache = NULL
+	}
+};
+
+static void *vvp_key_init(const struct lu_context *ctx,
+			  struct lu_context_key *key)
+{
+	struct vvp_thread_info *info;
+
+	OBD_SLAB_ALLOC_PTR_GFP(info, vvp_thread_kmem, __GFP_IO);
+	if (info == NULL)
+		info = ERR_PTR(-ENOMEM);
+	return info;
+}
+
+static void vvp_key_fini(const struct lu_context *ctx,
+			 struct lu_context_key *key, void *data)
+{
+	struct vvp_thread_info *info = data;
+	OBD_SLAB_FREE_PTR(info, vvp_thread_kmem);
+}
+
+static void *vvp_session_key_init(const struct lu_context *ctx,
+				  struct lu_context_key *key)
+{
+	struct vvp_session *session;
+
+	OBD_SLAB_ALLOC_PTR_GFP(session, vvp_session_kmem, __GFP_IO);
+	if (session == NULL)
+		session = ERR_PTR(-ENOMEM);
+	return session;
+}
+
+static void vvp_session_key_fini(const struct lu_context *ctx,
+				 struct lu_context_key *key, void *data)
+{
+	struct vvp_session *session = data;
+	OBD_SLAB_FREE_PTR(session, vvp_session_kmem);
+}
+
+
+struct lu_context_key vvp_key = {
+	.lct_tags = LCT_CL_THREAD,
+	.lct_init = vvp_key_init,
+	.lct_fini = vvp_key_fini
+};
+
+struct lu_context_key vvp_session_key = {
+	.lct_tags = LCT_SESSION,
+	.lct_init = vvp_session_key_init,
+	.lct_fini = vvp_session_key_fini
+};
+
+/* type constructor/destructor: vvp_type_{init,fini,start,stop}(). */
+LU_TYPE_INIT_FINI(vvp, &ccc_key, &ccc_session_key, &vvp_key, &vvp_session_key);
+
+static const struct lu_device_operations vvp_lu_ops = {
+	.ldo_object_alloc      = vvp_object_alloc
+};
+
+static const struct cl_device_operations vvp_cl_ops = {
+	.cdo_req_init = ccc_req_init
+};
+
+static struct lu_device *vvp_device_alloc(const struct lu_env *env,
+					  struct lu_device_type *t,
+					  struct lustre_cfg *cfg)
+{
+	return ccc_device_alloc(env, t, cfg, &vvp_lu_ops, &vvp_cl_ops);
+}
+
+static const struct lu_device_type_operations vvp_device_type_ops = {
+	.ldto_init = vvp_type_init,
+	.ldto_fini = vvp_type_fini,
+
+	.ldto_start = vvp_type_start,
+	.ldto_stop  = vvp_type_stop,
+
+	.ldto_device_alloc = vvp_device_alloc,
+	.ldto_device_free  = ccc_device_free,
+	.ldto_device_init  = ccc_device_init,
+	.ldto_device_fini  = ccc_device_fini
+};
+
+struct lu_device_type vvp_device_type = {
+	.ldt_tags     = LU_DEVICE_CL,
+	.ldt_name     = LUSTRE_VVP_NAME,
+	.ldt_ops      = &vvp_device_type_ops,
+	.ldt_ctx_tags = LCT_CL_THREAD
+};
+
+/**
+ * A mutex serializing calls to vvp_inode_fini() under extreme memory
+ * pressure, when environments cannot be allocated.
+ */
+int vvp_global_init(void)
+{
+	int result;
+
+	result = lu_kmem_init(vvp_caches);
+	if (result == 0) {
+		result = ccc_global_init(&vvp_device_type);
+		if (result != 0)
+			lu_kmem_fini(vvp_caches);
+	}
+	return result;
+}
+
+void vvp_global_fini(void)
+{
+	ccc_global_fini(&vvp_device_type);
+	lu_kmem_fini(vvp_caches);
+}
+
+
+/*****************************************************************************
+ *
+ * mirror obd-devices into cl devices.
+ *
+ */
+
+int cl_sb_init(struct super_block *sb)
+{
+	struct ll_sb_info *sbi;
+	struct cl_device  *cl;
+	struct lu_env     *env;
+	int rc = 0;
+	int refcheck;
+
+	sbi  = ll_s2sbi(sb);
+	env = cl_env_get(&refcheck);
+	if (!IS_ERR(env)) {
+		cl = cl_type_setup(env, NULL, &vvp_device_type,
+				   sbi->ll_dt_exp->exp_obd->obd_lu_dev);
+		if (!IS_ERR(cl)) {
+			cl2ccc_dev(cl)->cdv_sb = sb;
+			sbi->ll_cl = cl;
+			sbi->ll_site = cl2lu_dev(cl)->ld_site;
+		}
+		cl_env_put(env, &refcheck);
+	} else
+		rc = PTR_ERR(env);
+	RETURN(rc);
+}
+
+int cl_sb_fini(struct super_block *sb)
+{
+	struct ll_sb_info *sbi;
+	struct lu_env     *env;
+	struct cl_device  *cld;
+	int		refcheck;
+	int		result;
+
+	ENTRY;
+	sbi = ll_s2sbi(sb);
+	env = cl_env_get(&refcheck);
+	if (!IS_ERR(env)) {
+		cld = sbi->ll_cl;
+
+		if (cld != NULL) {
+			cl_stack_fini(env, cld);
+			sbi->ll_cl = NULL;
+			sbi->ll_site = NULL;
+		}
+		cl_env_put(env, &refcheck);
+		result = 0;
+	} else {
+		CERROR("Cannot cleanup cl-stack due to memory shortage.\n");
+		result = PTR_ERR(env);
+	}
+	/*
+	 * If mount failed (sbi->ll_cl == NULL), and this there are no other
+	 * mounts, stop device types manually (this usually happens
+	 * automatically when last device is destroyed).
+	 */
+	lu_types_stop();
+	RETURN(result);
+}
+
+/****************************************************************************
+ *
+ * /proc/fs/lustre/llite/$MNT/dump_page_cache
+ *
+ ****************************************************************************/
+
+/*
+ * To represent contents of a page cache as a byte stream, following
+ * information if encoded in 64bit offset:
+ *
+ *       - file hash bucket in lu_site::ls_hash[]       28bits
+ *
+ *       - how far file is from bucket head	      4bits
+ *
+ *       - page index				   32bits
+ *
+ * First two data identify a file in the cache uniquely.
+ */
+
+#define PGC_OBJ_SHIFT (32 + 4)
+#define PGC_DEPTH_SHIFT (32)
+
+struct vvp_pgcache_id {
+	unsigned		 vpi_bucket;
+	unsigned		 vpi_depth;
+	uint32_t		 vpi_index;
+
+	unsigned		 vpi_curdep;
+	struct lu_object_header *vpi_obj;
+};
+
+static void vvp_pgcache_id_unpack(loff_t pos, struct vvp_pgcache_id *id)
+{
+	CLASSERT(sizeof(pos) == sizeof(__u64));
+
+	id->vpi_index  = pos & 0xffffffff;
+	id->vpi_depth  = (pos >> PGC_DEPTH_SHIFT) & 0xf;
+	id->vpi_bucket = ((unsigned long long)pos >> PGC_OBJ_SHIFT);
+}
+
+static loff_t vvp_pgcache_id_pack(struct vvp_pgcache_id *id)
+{
+	return
+		((__u64)id->vpi_index) |
+		((__u64)id->vpi_depth  << PGC_DEPTH_SHIFT) |
+		((__u64)id->vpi_bucket << PGC_OBJ_SHIFT);
+}
+
+static int vvp_pgcache_obj_get(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+			       struct hlist_node *hnode, void *data)
+{
+	struct vvp_pgcache_id   *id  = data;
+	struct lu_object_header *hdr = cfs_hash_object(hs, hnode);
+
+	if (id->vpi_curdep-- > 0)
+		return 0; /* continue */
+
+	if (lu_object_is_dying(hdr))
+		return 1;
+
+	cfs_hash_get(hs, hnode);
+	id->vpi_obj = hdr;
+	return 1;
+}
+
+static struct cl_object *vvp_pgcache_obj(const struct lu_env *env,
+					 struct lu_device *dev,
+					 struct vvp_pgcache_id *id)
+{
+	LASSERT(lu_device_is_cl(dev));
+
+	id->vpi_depth &= 0xf;
+	id->vpi_obj    = NULL;
+	id->vpi_curdep = id->vpi_depth;
+
+	cfs_hash_hlist_for_each(dev->ld_site->ls_obj_hash, id->vpi_bucket,
+				vvp_pgcache_obj_get, id);
+	if (id->vpi_obj != NULL) {
+		struct lu_object *lu_obj;
+
+		lu_obj = lu_object_locate(id->vpi_obj, dev->ld_type);
+		if (lu_obj != NULL) {
+			lu_object_ref_add(lu_obj, "dump", current);
+			return lu2cl(lu_obj);
+		}
+		lu_object_put(env, lu_object_top(id->vpi_obj));
+
+	} else if (id->vpi_curdep > 0) {
+		id->vpi_depth = 0xf;
+	}
+	return NULL;
+}
+
+static loff_t vvp_pgcache_find(const struct lu_env *env,
+			       struct lu_device *dev, loff_t pos)
+{
+	struct cl_object     *clob;
+	struct lu_site       *site;
+	struct vvp_pgcache_id id;
+
+	site = dev->ld_site;
+	vvp_pgcache_id_unpack(pos, &id);
+
+	while (1) {
+		if (id.vpi_bucket >= CFS_HASH_NHLIST(site->ls_obj_hash))
+			return ~0ULL;
+		clob = vvp_pgcache_obj(env, dev, &id);
+		if (clob != NULL) {
+			struct cl_object_header *hdr;
+			int		      nr;
+			struct cl_page	  *pg;
+
+			/* got an object. Find next page. */
+			hdr = cl_object_header(clob);
+
+			spin_lock(&hdr->coh_page_guard);
+			nr = radix_tree_gang_lookup(&hdr->coh_tree,
+						    (void **)&pg,
+						    id.vpi_index, 1);
+			if (nr > 0) {
+				id.vpi_index = pg->cp_index;
+				/* Cant support over 16T file */
+				nr = !(pg->cp_index > 0xffffffff);
+			}
+			spin_unlock(&hdr->coh_page_guard);
+
+			lu_object_ref_del(&clob->co_lu, "dump", current);
+			cl_object_put(env, clob);
+			if (nr > 0)
+				return vvp_pgcache_id_pack(&id);
+		}
+		/* to the next object. */
+		++id.vpi_depth;
+		id.vpi_depth &= 0xf;
+		if (id.vpi_depth == 0 && ++id.vpi_bucket == 0)
+			return ~0ULL;
+		id.vpi_index = 0;
+	}
+}
+
+#define seq_page_flag(seq, page, flag, has_flags) do {		  \
+	if (test_bit(PG_##flag, &(page)->flags)) {		  \
+		seq_printf(seq, "%s"#flag, has_flags ? "|" : "");       \
+		has_flags = 1;					  \
+	}							       \
+} while(0)
+
+static void vvp_pgcache_page_show(const struct lu_env *env,
+				  struct seq_file *seq, struct cl_page *page)
+{
+	struct ccc_page *cpg;
+	struct page      *vmpage;
+	int	      has_flags;
+
+	cpg = cl2ccc_page(cl_page_at(page, &vvp_device_type));
+	vmpage = cpg->cpg_page;
+	seq_printf(seq," %5i | %p %p %s %s %s %s | %p %lu/%u(%p) %lu %u [",
+		   0 /* gen */,
+		   cpg, page,
+		   "none",
+		   cpg->cpg_write_queued ? "wq" : "- ",
+		   cpg->cpg_defer_uptodate ? "du" : "- ",
+		   PageWriteback(vmpage) ? "wb" : "-",
+		   vmpage, vmpage->mapping->host->i_ino,
+		   vmpage->mapping->host->i_generation,
+		   vmpage->mapping->host, vmpage->index,
+		   page_count(vmpage));
+	has_flags = 0;
+	seq_page_flag(seq, vmpage, locked, has_flags);
+	seq_page_flag(seq, vmpage, error, has_flags);
+	seq_page_flag(seq, vmpage, referenced, has_flags);
+	seq_page_flag(seq, vmpage, uptodate, has_flags);
+	seq_page_flag(seq, vmpage, dirty, has_flags);
+	seq_page_flag(seq, vmpage, writeback, has_flags);
+	seq_printf(seq, "%s]\n", has_flags ? "" : "-");
+}
+
+static int vvp_pgcache_show(struct seq_file *f, void *v)
+{
+	loff_t		   pos;
+	struct ll_sb_info       *sbi;
+	struct cl_object	*clob;
+	struct lu_env	   *env;
+	struct cl_page	  *page;
+	struct cl_object_header *hdr;
+	struct vvp_pgcache_id    id;
+	int		      refcheck;
+	int		      result;
+
+	env = cl_env_get(&refcheck);
+	if (!IS_ERR(env)) {
+		pos = *(loff_t *) v;
+		vvp_pgcache_id_unpack(pos, &id);
+		sbi = f->private;
+		clob = vvp_pgcache_obj(env, &sbi->ll_cl->cd_lu_dev, &id);
+		if (clob != NULL) {
+			hdr = cl_object_header(clob);
+
+			spin_lock(&hdr->coh_page_guard);
+			page = cl_page_lookup(hdr, id.vpi_index);
+			spin_unlock(&hdr->coh_page_guard);
+
+			seq_printf(f, "%8x@"DFID": ",
+				   id.vpi_index, PFID(&hdr->coh_lu.loh_fid));
+			if (page != NULL) {
+				vvp_pgcache_page_show(env, f, page);
+				cl_page_put(env, page);
+			} else
+				seq_puts(f, "missing\n");
+			lu_object_ref_del(&clob->co_lu, "dump", current);
+			cl_object_put(env, clob);
+		} else
+			seq_printf(f, "%llx missing\n", pos);
+		cl_env_put(env, &refcheck);
+		result = 0;
+	} else
+		result = PTR_ERR(env);
+	return result;
+}
+
+static void *vvp_pgcache_start(struct seq_file *f, loff_t *pos)
+{
+	struct ll_sb_info *sbi;
+	struct lu_env     *env;
+	int		refcheck;
+
+	sbi = f->private;
+
+	env = cl_env_get(&refcheck);
+	if (!IS_ERR(env)) {
+		sbi = f->private;
+		if (sbi->ll_site->ls_obj_hash->hs_cur_bits > 64 - PGC_OBJ_SHIFT)
+			pos = ERR_PTR(-EFBIG);
+		else {
+			*pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev,
+						*pos);
+			if (*pos == ~0ULL)
+				pos = NULL;
+		}
+		cl_env_put(env, &refcheck);
+	}
+	return pos;
+}
+
+static void *vvp_pgcache_next(struct seq_file *f, void *v, loff_t *pos)
+{
+	struct ll_sb_info *sbi;
+	struct lu_env     *env;
+	int		refcheck;
+
+	env = cl_env_get(&refcheck);
+	if (!IS_ERR(env)) {
+		sbi = f->private;
+		*pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev, *pos + 1);
+		if (*pos == ~0ULL)
+			pos = NULL;
+		cl_env_put(env, &refcheck);
+	}
+	return pos;
+}
+
+static void vvp_pgcache_stop(struct seq_file *f, void *v)
+{
+	/* Nothing to do */
+}
+
+static struct seq_operations vvp_pgcache_ops = {
+	.start = vvp_pgcache_start,
+	.next  = vvp_pgcache_next,
+	.stop  = vvp_pgcache_stop,
+	.show  = vvp_pgcache_show
+};
+
+static int vvp_dump_pgcache_seq_open(struct inode *inode, struct file *filp)
+{
+	struct ll_sb_info     *sbi = PDE_DATA(inode);
+	struct seq_file       *seq;
+	int		    result;
+
+	result = seq_open(filp, &vvp_pgcache_ops);
+	if (result == 0) {
+		seq = filp->private_data;
+		seq->private = sbi;
+	}
+	return result;
+}
+
+struct file_operations vvp_dump_pgcache_file_ops = {
+	.owner   = THIS_MODULE,
+	.open    = vvp_dump_pgcache_seq_open,
+	.read    = seq_read,
+	.llseek	 = seq_lseek,
+	.release = seq_release,
+};