[Linux-cachefs] [PATCH 1/2] Fscache glue implementation for Ceph
Yan, Zheng
ukernel at gmail.com
Fri Jun 21 06:49:45 UTC 2013
On Thu, Jun 20, 2013 at 11:43 AM, Milosz Tanski <milosz at adfin.com> wrote:
>
> The facilities needed for fscache support support. This part of the work is
> self contained in it's files and just getting Ceph ready.
>
> Signed-off-by: Milosz Tanski <milosz at adfin.com>
> ---
> fs/ceph/cache.c | 334 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> fs/ceph/cache.h | 115 +++++++++++++++++++
> 2 files changed, 449 insertions(+)
> create mode 100644 fs/ceph/cache.c
> create mode 100644 fs/ceph/cache.h
>
> diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c
> new file mode 100644
> index 0000000..f320d0e
> --- /dev/null
> +++ b/fs/ceph/cache.c
> @@ -0,0 +1,334 @@
> +/*
> + * Ceph cache definitions.
> + *
> + * Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
> + * Written by Milosz Tanski (milosz at adfin.com)
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * 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 for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to:
> + * Free Software Foundation
> + * 51 Franklin Street, Fifth Floor
> + * Boston, MA 02111-1301 USA
> + *
> + */
> +
> +#include "super.h"
> +#include "cache.h"
> +
> +struct ceph_aux_inode {
> + struct timespec mtime;
> + loff_t size;
> +};
> +
> +struct fscache_netfs ceph_cache_netfs = {
> + .name = "ceph",
> + .version = 0,
> +};
> +
> +static uint16_t ceph_fscache_session_get_key(const void *cookie_netfs_data,
> + void *buffer, uint16_t maxbuf)
> +{
> + const struct ceph_fs_client* fsc = cookie_netfs_data;
> + uint16_t klen;
> +
> + klen = sizeof(fsc->client->fsid);
> + if (klen > maxbuf)
> + return 0;
> +
> + memcpy(buffer, &fsc->client->fsid, klen);
> + return klen;
> +}
> +
> +static const struct fscache_cookie_def ceph_fscache_fsid_object_def = {
> + .name = "CEPH.fsid",
> + .type = FSCACHE_COOKIE_TYPE_INDEX,
> + .get_key = ceph_fscache_session_get_key,
> +};
> +
> +void ceph_fscache_register_fsid_cookie(struct ceph_fs_client* fsc)
> +{
> + fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index,
> + &ceph_fscache_fsid_object_def,
> + fsc);
> +}
> +
> +void ceph_fscache_unregister_fsid_cookie(struct ceph_fs_client* fsc)
> +{
> + fscache_relinquish_cookie(fsc->fscache, 0);
> + fsc->fscache = NULL;
> +}
> +
> +static uint16_t ceph_fscache_inode_get_key(const void *cookie_netfs_data,
> + void *buffer, uint16_t maxbuf)
> +{
> + const struct ceph_inode_info* ci = cookie_netfs_data;
> + uint16_t klen;
> +
> + /* use ceph virtual inode (id + snaphot) */
> + klen = sizeof(ci->i_vino);
> + if (klen > maxbuf)
> + return 0;
> +
> + memcpy(buffer, &ci->i_vino, klen);
> + return klen;
> +}
> +
> +static uint16_t ceph_fscache_inode_get_aux(const void *cookie_netfs_data,
> + void *buffer, uint16_t bufmax)
> +{
> + struct ceph_aux_inode aux;
> + const struct ceph_inode_info* ci = cookie_netfs_data;
> + const struct inode* inode = &ci->vfs_inode;
> +
> + memset(&aux, 0, sizeof(aux));
> + aux.mtime = inode->i_mtime;
> + aux.size = inode->i_size;
> +
> + memcpy(buffer, &aux, sizeof(aux));
> +
> + return sizeof(aux);
> +}
> +
> +static void ceph_fscache_inode_get_attr(const void *cookie_netfs_data,
> + uint64_t *size)
> +{
> + const struct ceph_inode_info* ci = cookie_netfs_data;
> + const struct inode* inode = &ci->vfs_inode;
> +
> + *size = inode->i_size;
> +}
> +
> +static enum fscache_checkaux ceph_fscache_inode_check_aux(
> + void *cookie_netfs_data, const void *data, uint16_t dlen)
> +{
> + struct ceph_aux_inode aux;
> + struct ceph_inode_info* ci = cookie_netfs_data;
> + struct inode* inode = &ci->vfs_inode;
> +
> + if (dlen != sizeof(aux))
> + return FSCACHE_CHECKAUX_OBSOLETE;
> +
> + memset(&aux, 0, sizeof(aux));
> + aux.mtime = inode->i_mtime;
> + aux.size = inode->i_size;
> +
> + if (memcmp(data, &aux, sizeof(aux)) != 0)
> + return FSCACHE_CHECKAUX_OBSOLETE;
> +
> + dout("ceph inode 0x%p cached okay", ci);
> + return FSCACHE_CHECKAUX_OKAY;
> +}
> +
> +static void cifs_fscache_inode_now_uncached(void* cookie_netfs_data)
> +{
> + struct ceph_inode_info* ci = cookie_netfs_data;
> + struct pagevec pvec;
> + pgoff_t first;
> + int loop, nr_pages;
> +
> + pagevec_init(&pvec, 0);
> + first = 0;
> +
> + dout("ceph inode 0x%p now uncached", ci);
> +
> + while (1) {
> + nr_pages = pagevec_lookup(&pvec, ci->vfs_inode.i_mapping, first,
> + PAGEVEC_SIZE - pagevec_count(&pvec));
> +
> + if (!nr_pages)
> + break;
> +
> + for (loop = 0; loop < nr_pages; loop++)
> + ClearPageFsCache(pvec.pages[loop]);
> +
> + first = pvec.pages[nr_pages - 1]->index + 1;
> +
> + pvec.nr = nr_pages;
> + pagevec_release(&pvec);
> + cond_resched();
> + }
> +}
> +
> +static const struct fscache_cookie_def ceph_fscache_inode_object_def = {
> + .name = "CEPH.inode",
> + .type = FSCACHE_COOKIE_TYPE_DATAFILE,
> + .get_key = ceph_fscache_inode_get_key,
> + .get_attr = ceph_fscache_inode_get_attr,
> + .get_aux = ceph_fscache_inode_get_aux,
> + .check_aux = ceph_fscache_inode_check_aux,
> + .now_uncached = cifs_fscache_inode_now_uncached,
> +};
> +
> +
> +static int get_caps_issued(struct ceph_inode_info* ci)
> +{
> + int issued;
> + int implemented = 0;
> +
> + issued = __ceph_caps_issued(ci, &implemented);
> + issued |= implemented | __ceph_caps_dirty(ci);
> + return issued;
> +}
> +
> +
> +void ceph_fscache_register_inode_cookie(struct ceph_fs_client* fsc,
> + struct ceph_inode_info* ci)
> +{
> + const int want = (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO);
> +
> + /* No caching for filesystem */
> + if (fsc->fscache == NULL)
> + return;
> + /* Only do it for data files */
> + if ((ci->vfs_inode.i_mode & S_IFREG) == 0)
> + return;
> +
> + if (ci->fscache)
> + return;
> + if ((get_caps_issued(ci) & want) == 0) {
> + dout("No caps for caching inode: %p", &ci->vfs_inode);
> + return;
> + }
> +
> + ci->fscache = fscache_acquire_cookie(fsc->fscache,
> + &ceph_fscache_inode_object_def,
> + ci);
> +}
> +
> +void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
> +{
> + if (ci->fscache == NULL)
> + return;
> +
> + fscache_relinquish_cookie(ci->fscache, 0);
> + ci->fscache = NULL;
> +}
> +
> +void ceph_fscache_revoke_inode_cookie(struct ceph_inode_info* ci)
> +{
> + if (ci->fscache == NULL)
> + return;
> +
> + fscache_invalidate(ci->fscache);
> + /* Make sure the cache is cleared after we close the handle */
> + fscache_relinquish_cookie(ci->fscache, 1);
> + ci->fscache = NULL;
> +}
> +
> +void __ceph_fsache_async_uncache_inode(struct ceph_inode_info* ci)
s/fsache/fscache
>
> +{
> + fscache_uncache_all_inode_pages(ci->fscache, &ci->vfs_inode);
> +}
> +
> +static void ceph_vfs_readpage_complete(struct page *page, void *data,
> int error)
> +{
> + if (!error)
> + SetPageUptodate(page);
> +}
> +
> +static void ceph_vfs_readpage_complete_unlock(struct page *page, void
> *data, int error)
> +{
> + if (!error) {
> + SetPageUptodate(page);
> + unlock_page(page);
> + }
> +}
> +
> +/* Atempt to read from the fscache,
> + *
> + * This function is called from the readpage_nounlock context. DO NOT
> attempt to
> + * unlock the page here (or in the callback).
> + */
> +int __ceph_readpage_from_fscache(struct inode *inode, struct page *page)
> +{
> + const struct ceph_inode_info *ci = ceph_inode(inode);
> + int ret;
> +
> + ret = fscache_read_or_alloc_page(ci->fscache, page,
> + ceph_vfs_readpage_complete, NULL,
> + GFP_KERNEL);
> +
> + switch (ret) {
> + case 0: /* Page found */
> + dout("page read submitted\n");
> + return 0;
> + case -ENOBUFS: /* Pages were not found, and can't be */
> + case -ENODATA: /* Pages were not found */
> + dout("page/inode not in cache\n");
> + return 1;
> + default:
> + dout("%s: unknown error ret = %i\n", __func__, ret);
> + return ret;
> + }
> +}
> +
> +int __ceph_readpages_from_fscache(struct inode *inode,
> + struct address_space *mapping,
> + struct list_head *pages,
> + unsigned *nr_pages)
> +{
> + struct ceph_inode_info *ci = ceph_inode(inode);
> + int issued = get_caps_issued(ci);
> + const int want = (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO);
> + int ret;
> +
> + /* Check if we have cached read caps */
> + if ((issued & want) == 0) {
> + return -ENOBUFS;
> + }
> +
> + ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages,
> + ceph_vfs_readpage_complete_unlock,
> + NULL, mapping_gfp_mask(mapping));
> +
> + switch (ret) {
> + case 0: /* All pages found */
> + dout("all-page read submitted\n");
> + return 0;
> + case -ENOBUFS: /* Some pages were not found, and can't be */
> + case -ENODATA: /* some pages were not found */
> + dout("page/inode not in cache\n");
> + return 1;
> + default:
> + dout("%s: unknown error ret = %i\n", __func__, ret);
> + return ret;
> + }
> +}
> +
> +void __ceph_readpage_to_fscache(struct inode *inode, struct page *page)
> +{
> + const struct ceph_inode_info *ci = ceph_inode(inode);
> + int ret;
> +
> + ret = fscache_write_page(ci->fscache, page, GFP_KERNEL);
> + if (ret)
> + fscache_uncache_page(ci->fscache, page);
> +}
> +
> +void __ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
> +{
> + const struct ceph_inode_info *ci = ceph_inode(inode);
> + struct fscache_cookie *cookie = ci->fscache;
> +
> + fscache_wait_on_page_write(cookie, page);
> + fscache_uncache_page(cookie, page);
> +}
> +
> +int __ceph_release_fscache_page(struct page *page, gfp_t gfp)
> +{
> + struct inode* inode = page->mapping->host;
> + struct ceph_inode_info *ci = ceph_inode(inode);
> + struct fscache_cookie *cookie = ci->fscache;
> +
> + return fscache_maybe_release_page(cookie, page, gfp);
> +}
> +
> diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
> new file mode 100644
> index 0000000..e7806cf
> --- /dev/null
> +++ b/fs/ceph/cache.h
> @@ -0,0 +1,115 @@
> +/*
> + * Ceph cache definitions.
> + *
> + * Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
> + * Written by Milosz Tanski (milosz at adfin.com)
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * 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 for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to:
> + * Free Software Foundation
> + * 51 Franklin Street, Fifth Floor
> + * Boston, MA 02111-1301 USA
> + *
> + */
> +
> +#ifndef _CEPH_CACHE_H
> +#define _CEPH_CACHE_H
> +#ifdef CONFIG_CEPH_FSCACHE
> +
> +#include <linux/fscache.h>
> +
> +
> +extern struct fscache_netfs ceph_cache_netfs;
> +
> +
> +void ceph_fscache_inode_get_cookie(struct inode *inode);
> +
> +void ceph_fscache_register_fsid_cookie(struct ceph_fs_client* fsc);
> +void ceph_fscache_unregister_fsid_cookie(struct ceph_fs_client* fsc);
> +void ceph_fscache_register_inode_cookie(struct ceph_fs_client* parent_fsc,
> + struct ceph_inode_info* ci);
> +void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci);
> +void ceph_fscache_revoke_inode_cookie(struct ceph_inode_info* ci);
> +void __ceph_fsache_async_uncache_inode(struct ceph_inode_info* ci);
> +
again
> +int __ceph_readpage_from_fscache(struct inode *inode, struct page *page);
> +int __ceph_readpages_from_fscache(struct inode *inode,
> + struct address_space *mapping,
> + struct list_head *pages,
> + unsigned *nr_pages);
> +void __ceph_readpage_to_fscache(struct inode *inode, struct page *page);
> +void __ceph_invalidate_fscache_page(struct inode* inode, struct page *page);
> +int __ceph_release_fscache_page(struct page *page, gfp_t gfp);
> +
> +static inline void ceph_fsache_async_uncache_inode(struct inode* inode)
> +{
again
> + struct ceph_inode_info *ci = ceph_inode(inode);
> +
> + if (ci->fscache == NULL)
> + return;
> +
> + __ceph_fsache_async_uncache_inode(ci);
> +}
again
> +
> +static inline int ceph_readpage_from_fscache(struct inode *inode,
> + struct page *page)
> +{
> + if (ceph_inode(inode)->fscache == NULL)
> + return -ENOBUFS;
> +
> + return __ceph_readpage_from_fscache(inode, page);
> +}
> +
> +static inline int ceph_readpages_from_fscache(struct inode *inode,
> + struct address_space *mapping,
> + struct list_head *pages,
> + unsigned *nr_pages)
> +{
> + if (ceph_inode(inode)->fscache == NULL)
> + return -ENOBUFS;
> +
> + return __ceph_readpages_from_fscache(inode, mapping, pages, nr_pages);
> +}
> +
> +static inline void ceph_readpage_to_fscache(struct inode *inode,
> + struct page *page)
> +{
> + if (ceph_inode(inode)->fscache == NULL)
> + return;
> +
> + if (PageFsCache(page))
> + return __ceph_readpage_to_fscache(inode, page);
> +}
> +
> +static inline void ceph_invalidate_fscache_page(struct inode *inode,
> + struct page *page)
> +{
> + if (ceph_inode(inode)->fscache == NULL)
> + return;
> +
> + if (PageFsCache(page))
> + return __ceph_invalidate_fscache_page(inode, page);
> +}
> +
> +static inline int ceph_release_fscache_page(struct page *page, gfp_t gfp)
> +{
> + struct inode* inode = page->mapping->host;
> + struct ceph_inode_info *ci = ceph_inode(inode);
> +
> + if (ci->fscache == NULL)
> + return 1;
> +
> + return __ceph_release_fscache_page(page, gfp);
> +}
> +
> +#endif
> +#endif
> --
> 1.7.9.5
> --
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