On 2020/12/3 18:53, Qiaowei Ren wrote:
> This patch define the prototype data structures in memory and initializes
> the nvm pages allocator.
>
> The nv address space which is managed by this allocatior can consist of
> many nvm namespaces, and some namespaces can compose into one nvm set,
> like cache set. For this initial implementation, only one set can be
> supported.
>
> The users of this nvm pages allocator need to call regiseter_namespace()
> to register the nvdimm device (like /dev/pmemX) into this allocator as
> the instance of struct nvm_namespace.
>
> Signed-off-by: Jianpeng Ma <jianpeng.ma@xxxxxxxxx>
> Signed-off-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx>
> ---
> drivers/md/bcache/Kconfig | 6 +
> drivers/md/bcache/Makefile | 2 +-
> drivers/md/bcache/nvm-pages.c | 303 ++++++++++++++++++++++++++++++++++
> drivers/md/bcache/nvm-pages.h | 91 ++++++++++
> drivers/md/bcache/super.c | 3 +
> 5 files changed, 404 insertions(+), 1 deletion(-)
> create mode 100644 drivers/md/bcache/nvm-pages.c
> create mode 100644 drivers/md/bcache/nvm-pages.h
>
> diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig
> index d1ca4d059c20..448a99ce13b2 100644
> --- a/drivers/md/bcache/Kconfig
> +++ b/drivers/md/bcache/Kconfig
> @@ -35,3 +35,9 @@ config BCACHE_ASYNC_REGISTRATION
> device path into this file will returns immediately and the real
> registration work is handled in kernel work queue in asynchronous
> way.
> +
> +config BCACHE_NVM_PAGES
> + bool "NVDIMM support for bcache"
> + depends on BCACHE
> + help
> + nvm pages allocator for bcache.
> diff --git a/drivers/md/bcache/Makefile b/drivers/md/bcache/Makefile
> index 5b87e59676b8..948e5ed2ca66 100644
> --- a/drivers/md/bcache/Makefile
> +++ b/drivers/md/bcache/Makefile
> @@ -4,4 +4,4 @@ obj-$(CONFIG_BCACHE) += bcache.o
>
> bcache-y := alloc.o bset.o btree.o closure.o debug.o extents.o\
> io.o journal.o movinggc.o request.o stats.o super.o sysfs.o trace.o\
> - util.o writeback.o features.o
> + util.o writeback.o features.o nvm-pages.o
> diff --git a/drivers/md/bcache/nvm-pages.c b/drivers/md/bcache/nvm-pages.c
> new file mode 100644
> index 000000000000..841616ea3267
> --- /dev/null
> +++ b/drivers/md/bcache/nvm-pages.c
> @@ -0,0 +1,303 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <linux/slab.h>
> +#include <linux/list.h>
> +#include <linux/mutex.h>
> +#include <linux/dax.h>
> +#include <linux/pfn_t.h>
> +#include <linux/libnvdimm.h>
> +#include <linux/mm_types.h>
> +#include <linux/err.h>
> +#include <linux/pagemap.h>
> +#include <linux/bitmap.h>
> +#include <linux/blkdev.h>
> +#include "nvm-pages.h"
> +
> +struct nvm_set *only_set;
> +
> +static struct owner_list *alloc_owner_list(const char *owner_uuid,
> + const char *label, int total_namespaces)
> +{
> + struct owner_list *owner_list;
> +
> + owner_list = kzalloc(sizeof(struct owner_list), GFP_KERNEL);
Should we check whether kzalloc(GFP_KERNEL) returns NULL?
or use __GFP_NOFAIL flag when calling kzalloc()?
There are several similar cases in other patches.
> + if (owner_uuid)
> + memcpy(owner_list->owner_uuid, owner_uuid, 16);
> + if (label)
> + memcpy(owner_list->label, label, NVM_PAGES_LABEL_SIZE);
> + owner_list->alloced_recs = kcalloc(total_namespaces,
> + sizeof(struct nvm_alloced_recs *), GFP_KERNEL);
> +
> + return owner_list;
> +}
> +
> +static void release_extents(struct nvm_alloced_recs *extents)
> +{
> + struct list_head *list = extents->extent_head.next;
> + struct extent *extent;
> +
> + while (list != &extents->extent_head) {
> + extent = container_of(list, struct extent, list);
> + list_del(list);
> + kfree(extent);
> + list = extents->extent_head.next;
> + }
> + kfree(extents);
> +}
> +
> +static void release_owner_info(struct nvm_set *nvm_set)
> +{
> + struct owner_list *owner_list;
> + int i, j;
> +
> + for (i = 0; i < nvm_set->owner_list_size; i++) {
> + owner_list = nvm_set->owner_lists[i];
> + for (j = 0; j < nvm_set->total_namespaces_nr; j++) {
> + if (owner_list->alloced_recs[j])
> + release_extents(owner_list->alloced_recs[j]);
> + }
> + kfree(owner_list->alloced_recs);
> + kfree(owner_list);
> + }
> + kfree(nvm_set->owner_lists);
> +}
> +
> +static void release_nvm_namespaces(struct nvm_set *nvm_set)
> +{
> + int i;
> +
> + for (i = 0; i < nvm_set->total_namespaces_nr; i++)
> + kfree(nvm_set->nss[i]);
> +
> + kfree(nvm_set->nss);
> +}
> +
> +static void release_nvm_set(struct nvm_set *nvm_set)
> +{
> + release_nvm_namespaces(nvm_set);
> + release_owner_info(nvm_set);
> + kfree(nvm_set);
> +}
> +
> +static void *nvm_pgoff_to_vaddr(struct nvm_namespace *ns, pgoff_t pgoff)
> +{
> + return ns->kaddr + ns->pages_offset + (pgoff << PAGE_SHIFT);
> +}
> +
> +static void init_owner_info(struct nvm_namespace *ns)
> +{
> + struct owner_list_head *owner_list_head;
> + struct nvm_pages_owner_head *owner_head;
> + struct nvm_pgalloc_recs *nvm_pgalloc_recs;
> + struct owner_list *owner_list;
> + struct nvm_alloced_recs *extents;
> + struct extent *extent;
> + u32 i, j, k;
> +
> + owner_list_head = (struct owner_list_head *)
> + (ns->kaddr + NVM_PAGES_OWNER_LIST_HEAD_OFFSET);
> +
> + mutex_lock(&only_set->lock);
> + only_set->owner_list_size = owner_list_head->size;
> + for (i = 0; i < owner_list_head->size; i++) {
> + owner_head = &owner_list_head->heads[i];
> + owner_list = alloc_owner_list(owner_head->uuid, owner_head->label,
> + only_set->total_namespaces_nr);
> +
> + for (j = 0; j < only_set->total_namespaces_nr; j++) {
> + if (only_set->nss[j] == NULL || owner_head->recs[j] == NULL)
> + continue;
> +
> + nvm_pgalloc_recs = (struct nvm_pgalloc_recs *)
> + ((long)owner_head->recs[j] + ns->kaddr);
> +
> + extents = kzalloc(sizeof(struct nvm_alloced_recs), GFP_KERNEL);
> + extents->ns = only_set->nss[j];
> + INIT_LIST_HEAD(&extents->extent_head);
> + owner_list->alloced_recs[j] = extents;
> +
> + do {
> + struct nvm_pgalloc_rec *rec;
> +
> + for (k = 0; k < nvm_pgalloc_recs->size; k++) {
> + rec = &nvm_pgalloc_recs->recs[k];
> + extent = kzalloc(sizeof(struct extent), GFP_KERNEL);
> + extent->kaddr = nvm_pgoff_to_vaddr(extents->ns, rec->pgoff);
> + extent->nr = rec->nr;
> + list_add_tail(&extent->list, &extents->extent_head);
> +
> + extents->ns->free -= rec->nr;
> + }
> + extents->size += nvm_pgalloc_recs->size;
> +
> + if (nvm_pgalloc_recs->next)
> + nvm_pgalloc_recs = (struct nvm_pgalloc_recs *)
> + ((long)nvm_pgalloc_recs->next + ns->kaddr);
> + else
> + nvm_pgalloc_recs = NULL;
> + } while (nvm_pgalloc_recs);
> + }
> + only_set->owner_lists[i] = owner_list;
> + owner_list->nvm_set = only_set;
> + }
> + mutex_unlock(&only_set->lock);
> +}
> +
> +static bool dev_dax_supported(struct block_device *bdev)
> +{
> + char buf[BDEVNAME_SIZE];
> + struct page *page;
> + struct nvm_pages_sb *sb;
> + bool supported = false;
> +
> + page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
> + NVM_PAGES_SB_OFFSET >> PAGE_SHIFT, GFP_KERNEL);
> +
> + if (IS_ERR(page))
> + goto err;
> +
> + sb = page_address(page);
> + if (!bdev_dax_supported(bdev, sb->page_size))
> + pr_info("DAX can't supported by %s\n", bdevname(bdev, buf));
> + else
> + supported = true;
> +
> + put_page(page);
> +err:
> + return supported;
> +}
> +
> +static bool attach_nvm_set(struct nvm_namespace *ns)
> +{
> + bool rc = true;
> +
> + mutex_lock(&only_set->lock);
> + if (only_set->nss) {
> + if (memcmp(ns->sb->set_uuid, only_set->set_uuid, 16)) {
> + pr_info("namespace id does't match nvm set\n");
> + rc = false;
> + goto unlock;
> + }
> +
> + if (only_set->nss[ns->sb->this_namespace_nr]) {
> + pr_info("already has the same position(%d) nvm\n",
> + ns->sb->this_namespace_nr);
> + rc = false;
> + goto unlock;
> + }
> + } else {
> + memcpy(only_set->set_uuid, ns->sb->set_uuid, 16);
> + only_set->total_namespaces_nr = ns->sb->total_namespaces_nr;
> + only_set->nss = kcalloc(only_set->total_namespaces_nr,
> + sizeof(struct nvm_namespace *), GFP_KERNEL);
> + only_set->owner_lists = kcalloc(MAX_OWNER_LIST,
> + sizeof(struct nvm_pages_owner_head *), GFP_KERNEL);
> + }
> +
> + only_set->nss[ns->sb->this_namespace_nr] = ns;
> +
> +unlock:
> + mutex_unlock(&only_set->lock);
> + return rc;
> +}
> +
> +struct nvm_namespace *register_namespace(const char *dev_path)
> +{
> + struct nvm_namespace *ns;
> + int err;
> + pgoff_t pgoff;
> + char buf[BDEVNAME_SIZE];
> + struct block_device *bdev;
> +
> + bdev = blkdev_get_by_path(dev_path, FMODE_READ|FMODE_WRITE|FMODE_EXEC, NULL);
> + if (IS_ERR(bdev)) {
> + pr_info("get %s error\n", dev_path);
> + return ERR_PTR(PTR_ERR(bdev));
> + }
> +
> + err = -EOPNOTSUPP;
> + if (!dev_dax_supported(bdev)) {
> + pr_info("%s don't support DAX\n", bdevname(bdev, buf));
> + goto bdput;
> + }
> +
> + err = -EINVAL;
> + if (bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff)) {
> + pr_info("invalid offset of %s\n", bdevname(bdev, buf));
> + goto bdput;
> + }
> +
> + err = -ENOMEM;
> + ns = kmalloc(sizeof(struct nvm_namespace), GFP_KERNEL);
> + if (ns == NULL)
> + goto bdput;
> +
> + err = -EINVAL;
> + ns->dax_dev = fs_dax_get_by_bdev(bdev);
> + if (ns->dax_dev == NULL) {
> + pr_info(" can't by dax device by %s\n", bdevname(bdev, buf));
small cleanup：
remove one useless space.
-> pr_info("can't by dax device by %s\n", bdevname(bdev, buf));
> + goto free_ns;
> + }
> +
> + if (dax_direct_access(ns->dax_dev, pgoff, 1, &ns->kaddr, &ns->start_pfn) < 0) {
> + pr_info("dax_direct_access error\n");
> + goto free_ns;
> + }
> +
> + ns->sb = (struct nvm_pages_sb *)(ns->kaddr + NVM_PAGES_SB_OFFSET);
> + if (ns->sb->total_namespaces_nr != 1) {
> + pr_info("only one nvm device\n");
> + goto free_ns;
> + }
> +
> + err = -EEXIST;
> + if (!attach_nvm_set(ns))
> + goto free_ns;
> +
> + ns->page_size = ns->sb->page_size;
> + ns->pages_offset = ns->sb->pages_offset;
> + ns->pages_total = ns->sb->pages_total;
> + ns->start_pfn.val += ns->pages_offset >> PAGE_SHIFT;
> + ns->free = ns->pages_total;
> + ns->bdev = bdev;
> + ns->nvm_set = only_set;
> +
> + mutex_init(&ns->lock);
> +
> + if (ns->sb->this_namespace_nr == 0) {
> + pr_info("only first namespace contain owner info\n");
> + init_owner_info(ns);
> + }
> +
> + return ns;
> +
> +free_ns:
> + kfree(ns);
> +bdput:
> + bdput(bdev);
> +
> + return ERR_PTR(err);
> +}
> +EXPORT_SYMBOL_GPL(register_namespace);
> +
> +int __init bch_nvm_init(void)
> +{
> + only_set = kzalloc(sizeof(struct nvm_set), GFP_KERNEL);
> + if (!only_set)
> + return -ENOMEM;
> +
> + only_set->total_namespaces_nr = 0;
> + only_set->owner_lists = NULL;
> + only_set->nss = NULL;
> +
> + mutex_init(&only_set->lock);
> +
> + pr_info("bcache nvm init\n");
> + return 0;
> +}
> +
> +void bch_nvm_exit(void)
> +{
> + release_nvm_set(only_set);
> + pr_info("bcache nvm exit\n");
> +}
> diff --git a/drivers/md/bcache/nvm-pages.h b/drivers/md/bcache/nvm-pages.h
> new file mode 100644
> index 000000000000..1a24af6cb5a9
> --- /dev/null
> +++ b/drivers/md/bcache/nvm-pages.h
> @@ -0,0 +1,91 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef _BCACHE_NVM_PAGES_H
> +#define _BCACHE_NVM_PAGES_H
> +
> +#include <linux/bcache-nvm.h>
> +
> +/*
> + * Bcache NVDIMM in memory data structures
> + */
> +
> +/*
> + * The following three structures in memory records which page(s) allocated
> + * to which owner. After reboot from power failure, they will be initialized
> + * based on nvm pages superblock in NVDIMM device.
> + */
> +struct extent {
> + void *kaddr;
> + u32 nr;
> + struct list_head list;
> +};
> +
> +struct nvm_alloced_recs {
> + u32 size;
> + struct nvm_namespace *ns;
> + struct list_head extent_head;
> +};
> +
> +struct owner_list {
> + u8 owner_uuid[16];
> + char label[NVM_PAGES_LABEL_SIZE];
> +
> + struct nvm_set *nvm_set;
> + struct nvm_alloced_recs **alloced_recs;
> +};
> +
> +struct nvm_namespace {
> + void *kaddr;
> +
> + u8 uuid[18];
> + u64 free;
> + u32 page_size;
> + u64 pages_offset;
> + u64 pages_total;
> + pfn_t start_pfn;
> +
> + struct dax_device *dax_dev;
> + struct block_device *bdev;
> + struct nvm_pages_sb *sb;
> + struct nvm_set *nvm_set;
> +
> + struct mutex lock;
> +};
> +
> +/*
> + * A set of namespaces. Currently only one set can be supported.
> + */
> +struct nvm_set {
> + u8 set_uuid[16];
> + u32 total_namespaces_nr;
> +
> + u32 owner_list_size;
> + struct owner_list **owner_lists;
> +
> + struct nvm_namespace **nss;
> +
> + struct mutex lock;
> +};
> +extern struct nvm_set *only_set;
> +
> +#ifdef CONFIG_BCACHE_NVM_PAGES
> +
> +extern struct nvm_namespace *register_namespace(const char *dev_path);
> +extern int bch_nvm_init(void);
> +extern void bch_nvm_exit(void);
> +
> +#else
> +
> +static inline struct nvm_namespace *register_namespace(const char *dev_path)
> +{
> + return NULL;
> +}
> +static inline int bch_nvm_init(void)
> +{
> + return 0;
> +}
> +static inline void bch_nvm_exit(void) { }
> +
> +#endif /* CONFIG_BCACHE_NVM_PAGES */
> +
> +#endif /* _BCACHE_NVM_PAGES_H */
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index 46a00134a36a..77b608efbe55 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -14,6 +14,7 @@
> #include "request.h"
> #include "writeback.h"
> #include "features.h"
> +#include "nvm-pages.h"
>
> #include <linux/blkdev.h>
> #include <linux/debugfs.h>
> @@ -2782,6 +2783,7 @@ static void bcache_exit(void)
> {
> bch_debug_exit();
> bch_request_exit();
> + bch_nvm_exit();
> if (bcache_kobj)
> kobject_put(bcache_kobj);
> if (bcache_wq)
> @@ -2861,6 +2863,7 @@ static int __init bcache_init(void)
>
> bch_debug_init();
> closure_debug_init();
> + bch_nvm_init();
>
> bcache_is_reboot = false;
>
>
