From patchwork Sat Sep 19 22:44:42 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abhishek Kulkarni X-Patchwork-Id: 48882 X-Patchwork-Delegate: ericvh@gmail.com Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n8JNxs3J006986 for ; Sat, 19 Sep 2009 23:59:54 GMT Received: from localhost ([127.0.0.1] helo=sfs-ml-2.v29.ch3.sourceforge.com) by 3yr0jf1.ch3.sourceforge.com with esmtp (Exim 4.69) (envelope-from ) id 1Mp9q2-0008Da-O3; Sat, 19 Sep 2009 23:59:34 +0000 Received: from sfi-mx-2.v28.ch3.sourceforge.com ([172.29.28.122] helo=mx.sourceforge.net) by 3yr0jf1.ch3.sourceforge.com with esmtp (Exim 4.69) (envelope-from ) id 1Mp9q1-0008D8-9m for v9fs-developer@lists.sourceforge.net; Sat, 19 Sep 2009 23:59:33 +0000 X-ACL-Warn: Received: from mail-yx0-f202.google.com ([209.85.210.202]) by 72vjzd1.ch3.sourceforge.com with esmtp (Exim 4.69) id 1Mp9pu-0004EG-U0 for v9fs-developer@lists.sourceforge.net; Sat, 19 Sep 2009 23:59:32 +0000 Received: by yxe40 with SMTP id 40so2480740yxe.28 for ; Sat, 19 Sep 2009 16:59:20 -0700 (PDT) Received: by 10.91.189.1 with SMTP id r1mr2117866agp.109.1253400324513; Sat, 19 Sep 2009 15:45:24 -0700 (PDT) Received: from localhost.localdomain (c-98-223-237-121.hsd1.in.comcast.net [98.223.237.121]) by mx.google.com with ESMTPS id 40sm5662714aga.44.2009.09.19.15.44.49 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sat, 19 Sep 2009 15:45:23 -0700 (PDT) From: Abhishek Kulkarni To: linux-kernel@vger.kernel.org Date: Sat, 19 Sep 2009 16:44:42 -0600 Message-Id: <1253400283-2575-1-git-send-email-adkulkar@umail.iu.edu> X-Mailer: git-send-email 1.6.3.3 X-Spam-Score: -2.0 (--) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -2.0 AWL AWL: From: address is in the auto white-list X-Headers-End: 1Mp9pu-0004EG-U0 Cc: v9fs-developer@lists.sourceforge.net Subject: [V9fs-developer] [PATCH 1/2] 9p: Add fscache support to 9p X-BeenThere: v9fs-developer@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: v9fs-developer-bounces@lists.sourceforge.net This patch adds a persistent, read-only caching facility for 9p clients using the FS-Cache caching backend. When the fscache facility is enabled, each inode is associated with a corresponding vcookie which is an index into the FS-Cache indexing tree. The FS-Cache indexing tree is indexed at 3 levels: - session object associated with each mount. - inode/vcookie - actual data (pages) A cache tag is chosen randomly for each session. These tags can be read off /sys/fs/9p/caches and can be passed as a mount-time parameter to re-attach to the specified caching session. Signed-off-by: Abhishek Kulkarni --- fs/9p/Kconfig | 9 + fs/9p/Makefile | 3 +- fs/9p/cache.c | 473 +++++++++++++++++++++++++++++++++++++++++++++++++++ fs/9p/cache.h | 175 +++++++++++++++++++ fs/9p/v9fs.c | 191 ++++++++++++++++++--- fs/9p/v9fs.h | 13 +- fs/9p/v9fs_vfs.h | 6 + fs/9p/vfs_addr.c | 88 ++++++++++- fs/9p/vfs_file.c | 10 +- fs/9p/vfs_inode.c | 56 ++++++- fs/9p/vfs_super.c | 16 +-- include/net/9p/9p.h | 3 + 12 files changed, 1001 insertions(+), 42 deletions(-) create mode 100644 fs/9p/cache.c create mode 100644 fs/9p/cache.h diff --git a/fs/9p/Kconfig b/fs/9p/Kconfig index 74e0723..7952337 100644 --- a/fs/9p/Kconfig +++ b/fs/9p/Kconfig @@ -8,3 +8,12 @@ config 9P_FS See for more information. If unsure, say N. + +config 9P_FSCACHE + bool "Enable 9P client caching support (EXPERIMENTAL)" + depends on EXPERIMENTAL + depends on 9P_FS=m && FSCACHE || 9P_FS=y && FSCACHE=y + help + Choose Y here to enable persistent, read-only local + caching support for 9p clients using FS-Cache + diff --git a/fs/9p/Makefile b/fs/9p/Makefile index bc7f0d1..1a940ec 100644 --- a/fs/9p/Makefile +++ b/fs/9p/Makefile @@ -8,5 +8,6 @@ obj-$(CONFIG_9P_FS) := 9p.o vfs_dir.o \ vfs_dentry.o \ v9fs.o \ - fid.o \ + fid.o +9p-$(CONFIG_9P_FSCACHE) += cache.o diff --git a/fs/9p/cache.c b/fs/9p/cache.c new file mode 100644 index 0000000..3f4dc0d --- /dev/null +++ b/fs/9p/cache.c @@ -0,0 +1,473 @@ +/* + * V9FS cache definitions. + * + * Copyright (C) 2009 by Abhishek Kulkarni + * + * 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 +#include +#include +#include +#include + +#include "v9fs.h" +#include "cache.h" + +#define CACHETAG_LEN 11 + +struct kmem_cache *vcookie_cache; + +struct fscache_netfs v9fs_cache_netfs = { + .name = "9p", + .version = 0, +}; + +static void init_once(void *foo) +{ + struct v9fs_cookie *vcookie = (struct v9fs_cookie *) foo; + vcookie->fscache = NULL; + vcookie->qid = NULL; + inode_init_once(&vcookie->inode); +} + +/** + * v9fs_init_vcookiecache - initialize a cache for vcookies to maintain + * vcookie to inode mapping + * + * Returns 0 on success. + */ + +static int v9fs_init_vcookiecache(void) +{ + vcookie_cache = kmem_cache_create("vcookie_cache", + sizeof(struct v9fs_cookie), + 0, (SLAB_RECLAIM_ACCOUNT| + SLAB_MEM_SPREAD), + init_once); + if (!vcookie_cache) + return -ENOMEM; + + return 0; +} + +/** + * v9fs_destroy_vcookiecache - destroy the cache of vcookies + * + */ + +static void v9fs_destroy_vcookiecache(void) +{ + kmem_cache_destroy(vcookie_cache); +} + +int __v9fs_cache_register(void) +{ + int ret; + ret = v9fs_init_vcookiecache(); + if (ret < 0) + return ret; + + return fscache_register_netfs(&v9fs_cache_netfs); +} + +void __v9fs_cache_unregister(void) +{ + v9fs_destroy_vcookiecache(); + fscache_unregister_netfs(&v9fs_cache_netfs); +} + +/** + * v9fs_random_cachetag - Generate a random tag to be associated + * with a new cache session. + * + * The value of jiffies is used for a fairly randomly cache tag. + */ + +static +int v9fs_random_cachetag(struct v9fs_session_info *v9ses) +{ + v9ses->cachetag = kmalloc(CACHETAG_LEN, GFP_KERNEL); + if (!v9ses->cachetag) + return -ENOMEM; + + return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies); +} + +static uint16_t v9fs_cache_session_get_key(const void *cookie_netfs_data, + void *buffer, uint16_t bufmax) +{ + struct v9fs_session_info *v9ses; + uint16_t klen = 0; + + v9ses = (struct v9fs_session_info *)cookie_netfs_data; + P9_DPRINTK(P9_DEBUG_FSC, "session %p buf %p size %u", v9ses, + buffer, bufmax); + + if (v9ses->cachetag) + klen = strlen(v9ses->cachetag); + + if (klen > bufmax) + return 0; + + memcpy(buffer, v9ses->cachetag, klen); + P9_DPRINTK(P9_DEBUG_FSC, "cache session tag %s", v9ses->cachetag); + return klen; +} + +const struct fscache_cookie_def v9fs_cache_session_index_def = { + .name = "9P.session", + .type = FSCACHE_COOKIE_TYPE_INDEX, + .get_key = v9fs_cache_session_get_key, +}; + +void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses) +{ + /* If no cache session tag was specified, we generate a random one. */ + if (!v9ses->cachetag) + v9fs_random_cachetag(v9ses); + + v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index, + &v9fs_cache_session_index_def, + v9ses); + P9_DPRINTK(P9_DEBUG_FSC, "session %p get cookie %p", v9ses, + v9ses->fscache); +} + +void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses) +{ + P9_DPRINTK(P9_DEBUG_FSC, "session %p put cookie %p", v9ses, + v9ses->fscache); + fscache_relinquish_cookie(v9ses->fscache, 0); + v9ses->fscache = NULL; +} + + +static uint16_t v9fs_cache_inode_get_key(const void *cookie_netfs_data, + void *buffer, uint16_t bufmax) +{ + const struct v9fs_cookie *vcookie = cookie_netfs_data; + memcpy(buffer, &vcookie->qid->path, sizeof(vcookie->qid->path)); + + P9_DPRINTK(P9_DEBUG_FSC, "inode %p get key %llu", &vcookie->inode, + vcookie->qid->path); + return sizeof(vcookie->qid->path); +} + +static void v9fs_cache_inode_get_attr(const void *cookie_netfs_data, + uint64_t *size) +{ + const struct v9fs_cookie *vcookie = cookie_netfs_data; + *size = i_size_read(&vcookie->inode); + + P9_DPRINTK(P9_DEBUG_FSC, "inode %p get attr %llu", &vcookie->inode, + *size); +} + +static uint16_t v9fs_cache_inode_get_aux(const void *cookie_netfs_data, + void *buffer, uint16_t buflen) +{ + const struct v9fs_cookie *vcookie = cookie_netfs_data; + memcpy(buffer, &vcookie->qid->version, sizeof(vcookie->qid->version)); + + P9_DPRINTK(P9_DEBUG_FSC, "inode %p get aux %u", &vcookie->inode, + vcookie->qid->version); + return sizeof(vcookie->qid->version); +} + +static enum +fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data, + const void *buffer, + uint16_t buflen) +{ + const struct v9fs_cookie *vcookie = cookie_netfs_data; + + if (buflen != sizeof(vcookie->qid->version)) + return FSCACHE_CHECKAUX_OBSOLETE; + + if (memcmp(buffer, &vcookie->qid->version, + sizeof(vcookie->qid->version))) + return FSCACHE_CHECKAUX_OBSOLETE; + + return FSCACHE_CHECKAUX_OKAY; +} + +static void v9fs_cache_inode_now_uncached(void *cookie_netfs_data) +{ + struct v9fs_cookie *vcookie = cookie_netfs_data; + struct pagevec pvec; + pgoff_t first; + int loop, nr_pages; + + pagevec_init(&pvec, 0); + first = 0; + + for (;;) { + nr_pages = pagevec_lookup(&pvec, vcookie->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(); + } +} + +const struct fscache_cookie_def v9fs_cache_inode_index_def = { + .name = "9p.inode", + .type = FSCACHE_COOKIE_TYPE_DATAFILE, + .get_key = v9fs_cache_inode_get_key, + .get_attr = v9fs_cache_inode_get_attr, + .get_aux = v9fs_cache_inode_get_aux, + .check_aux = v9fs_cache_inode_check_aux, + .now_uncached = v9fs_cache_inode_now_uncached, +}; + +void v9fs_cache_inode_get_cookie(struct inode *inode) +{ + struct v9fs_cookie *vcookie; + struct v9fs_session_info *v9ses; + + if (!S_ISREG(inode->i_mode)) + return; + + vcookie = v9fs_inode2cookie(inode); + if (vcookie->fscache) + return; + + v9ses = v9fs_inode2v9ses(inode); + vcookie->fscache = fscache_acquire_cookie(v9ses->fscache, + &v9fs_cache_inode_index_def, + vcookie); + + P9_DPRINTK(P9_DEBUG_FSC, "inode %p get cookie %p", inode, + vcookie->fscache); +} + +void v9fs_cache_inode_put_cookie(struct inode *inode) +{ + struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + + if (!vcookie->fscache) + return; + P9_DPRINTK(P9_DEBUG_FSC, "inode %p put cookie %p", inode, + vcookie->fscache); + + fscache_relinquish_cookie(vcookie->fscache, 0); + vcookie->fscache = NULL; +} + +void v9fs_cache_inode_flush_cookie(struct inode *inode) +{ + struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + + if (!vcookie->fscache) + return; + P9_DPRINTK(P9_DEBUG_FSC, "inode %p flush cookie %p", inode, + vcookie->fscache); + + fscache_relinquish_cookie(vcookie->fscache, 1); + vcookie->fscache = NULL; +} + +void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp) +{ + struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + struct p9_fid *fid; + + if (!vcookie->fscache) + return; + + spin_lock(&vcookie->lock); + fid = filp->private_data; + if ((filp->f_flags & O_ACCMODE) != O_RDONLY) + v9fs_cache_inode_flush_cookie(inode); + else + v9fs_cache_inode_get_cookie(inode); + + spin_unlock(&vcookie->lock); +} + +void v9fs_cache_inode_reset_cookie(struct inode *inode) +{ + struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + struct v9fs_session_info *v9ses; + struct fscache_cookie *old; + + if (!vcookie->fscache) + return; + + old = vcookie->fscache; + + spin_lock(&vcookie->lock); + fscache_relinquish_cookie(vcookie->fscache, 1); + + v9ses = v9fs_inode2v9ses(inode); + vcookie->fscache = fscache_acquire_cookie(v9ses->fscache, + &v9fs_cache_inode_index_def, + vcookie); + + P9_DPRINTK(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p", + inode, old, vcookie->fscache); + + spin_unlock(&vcookie->lock); +} + +int __v9fs_fscache_release_page(struct page *page, gfp_t gfp) +{ + struct inode *inode = page->mapping->host; + struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + + BUG_ON(!vcookie->fscache); + + if (PageFsCache(page)) { + if (fscache_check_page_write(vcookie->fscache, page)) { + if (!(gfp & __GFP_WAIT)) + return 0; + fscache_wait_on_page_write(vcookie->fscache, page); + } + + fscache_uncache_page(vcookie->fscache, page); + ClearPageFsCache(page); + } + + return 1; +} + +void __v9fs_fscache_invalidate_page(struct page *page) +{ + struct inode *inode = page->mapping->host; + struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + + BUG_ON(!vcookie->fscache); + + if (PageFsCache(page)) { + fscache_wait_on_page_write(vcookie->fscache, page); + BUG_ON(!PageLocked(page)); + fscache_uncache_page(vcookie->fscache, page); + ClearPageFsCache(page); + } +} + +static void v9fs_vfs_readpage_complete(struct page *page, void *data, + int error) +{ + if (!error) + SetPageUptodate(page); + + unlock_page(page); +} + +/** + * __v9fs_readpage_from_fscache - read a page from cache + * + * Returns 0 if the pages are in cache and a BIO is submitted, + * 1 if the pages are not in cache and -error otherwise. + */ + +int __v9fs_readpage_from_fscache(struct inode *inode, struct page *page) +{ + int ret; + const struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + + P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page); + if (!vcookie->fscache) + return -ENOBUFS; + + ret = fscache_read_or_alloc_page(vcookie->fscache, + page, + v9fs_vfs_readpage_complete, + NULL, + GFP_KERNEL); + switch (ret) { + case -ENOBUFS: + case -ENODATA: + P9_DPRINTK(P9_DEBUG_FSC, "page/inode not in cache %d", ret); + return 1; + case 0: + P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted"); + return ret; + default: + P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret); + return ret; + } +} + +/** + * __v9fs_readpages_from_fscache - read multiple pages from cache + * + * Returns 0 if the pages are in cache and a BIO is submitted, + * 1 if the pages are not in cache and -error otherwise. + */ + +int __v9fs_readpages_from_fscache(struct inode *inode, + struct address_space *mapping, + struct list_head *pages, + unsigned *nr_pages) +{ + int ret; + const struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + + P9_DPRINTK(P9_DEBUG_FSC, "inode %p pages %u", inode, *nr_pages); + if (!vcookie->fscache) + return -ENOBUFS; + + ret = fscache_read_or_alloc_pages(vcookie->fscache, + mapping, pages, nr_pages, + v9fs_vfs_readpage_complete, + NULL, + mapping_gfp_mask(mapping)); + switch (ret) { + case -ENOBUFS: + case -ENODATA: + P9_DPRINTK(P9_DEBUG_FSC, "pages/inodes not in cache %d", ret); + return 1; + case 0: + BUG_ON(!list_empty(pages)); + BUG_ON(*nr_pages != 0); + P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted"); + return ret; + default: + P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret); + return ret; + } +} + +/** + * __v9fs_readpage_to_fscache - write a page to the cache + * + */ + +void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page) +{ + int ret; + const struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + + P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page); + ret = fscache_write_page(vcookie->fscache, page, GFP_KERNEL); + P9_DPRINTK(P9_DEBUG_FSC, "ret = %d", ret); + if (ret != 0) + v9fs_uncache_page(inode, page); +} diff --git a/fs/9p/cache.h b/fs/9p/cache.h new file mode 100644 index 0000000..c91d161 --- /dev/null +++ b/fs/9p/cache.h @@ -0,0 +1,175 @@ +/* + * V9FS cache definitions. + * + * Copyright (C) 2009 by Abhishek Kulkarni + * + * 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 _9P_CACHE_H +#ifdef CONFIG_9P_FSCACHE +#include + +extern struct kmem_cache *vcookie_cache; + +struct v9fs_cookie { + spinlock_t lock; + struct inode inode; + struct fscache_cookie *fscache; + struct p9_qid *qid; +}; + +static inline struct v9fs_cookie *v9fs_inode2cookie(const struct inode *inode) +{ + return container_of(inode, struct v9fs_cookie, inode); +} + +extern struct fscache_netfs v9fs_cache_netfs; +extern const struct fscache_cookie_def v9fs_cache_session_index_def; +extern const struct fscache_cookie_def v9fs_cache_inode_index_def; + +void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses); +void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses); + +void v9fs_cache_inode_get_cookie(struct inode *inode); +void v9fs_cache_inode_put_cookie(struct inode *inode); +void v9fs_cache_inode_flush_cookie(struct inode *inode); +void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp); +void v9fs_cache_inode_reset_cookie(struct inode *inode); + +extern int __v9fs_cache_register(void); +extern void __v9fs_cache_unregister(void); + +extern int __v9fs_fscache_release_page(struct page *page, gfp_t gfp); +extern void __v9fs_fscache_invalidate_page(struct page *page); +extern int __v9fs_readpage_from_fscache(struct inode *inode, + struct page *page); +extern int __v9fs_readpages_from_fscache(struct inode *inode, + struct address_space *mapping, + struct list_head *pages, + unsigned *nr_pages); +extern void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page); + + +/** + * v9fs_cache_register - Register v9fs file system with the cache + */ +static inline int v9fs_cache_register(void) +{ + return __v9fs_cache_register(); +} + +/** + * v9fs_cache_unregister - Unregister v9fs from the cache + */ +static inline void v9fs_cache_unregister(void) +{ + __v9fs_cache_unregister(); +} + +static inline int v9fs_fscache_release_page(struct page *page, + gfp_t gfp) +{ + return __v9fs_fscache_release_page(page, gfp); +} + +static inline void v9fs_fscache_invalidate_page(struct page *page) +{ + __v9fs_fscache_invalidate_page(page); +} + +static inline int v9fs_readpage_from_fscache(struct inode *inode, + struct page *page) +{ + return __v9fs_readpage_from_fscache(inode, page); +} + +static inline int v9fs_readpages_from_fscache(struct inode *inode, + struct address_space *mapping, + struct list_head *pages, + unsigned *nr_pages) +{ + return __v9fs_readpages_from_fscache(inode, mapping, pages, + nr_pages); +} + +static inline void v9fs_readpage_to_fscache(struct inode *inode, + struct page *page) +{ + if (PageFsCache(page)) + __v9fs_readpage_to_fscache(inode, page); +} + +static inline void v9fs_uncache_page(struct inode *inode, struct page *page) +{ + struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + fscache_uncache_page(vcookie->fscache, page); + BUG_ON(PageFsCache(page)); +} + +static inline void v9fs_vcookie_set_qid(struct inode *inode, + struct p9_qid *qid) +{ + struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode); + spin_lock(&vcookie->lock); + vcookie->qid = qid; + spin_unlock(&vcookie->lock); +} + +#else /* CONFIG_9P_FSCACHE */ + +static inline int v9fs_cache_register(void) +{ + return 1; +} + +static inline void v9fs_cache_unregister(void) {} + +static inline int v9fs_fscache_release_page(struct page *page, + gfp_t gfp) { + return 1; +} + +static inline void v9fs_fscache_invalidate_page(struct page *page) {} + +static inline int v9fs_readpage_from_fscache(struct inode *inode, + struct page *page) +{ + return -ENOBUFS; +} + +static inline int v9fs_readpages_from_fscache(struct inode *inode, + struct address_space *mapping, + struct list_head *pages, + unsigned *nr_pages) +{ + return -ENOBUFS; +} + +static inline void v9fs_readpage_to_fscache(struct inode *inode, + struct page *page) +{} + +static inline void v9fs_uncache_page(struct inode *inode, struct page *page) +{} + +static inline void v9fs_vcookie_set_qid(struct inode *inode, + struct p9_qid *qid) +{} + +#endif /* CONFIG_9P_FSCACHE */ +#endif /* _9P_CACHE_H */ diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c index f7003cf..f4a5950 100644 --- a/fs/9p/v9fs.c +++ b/fs/9p/v9fs.c @@ -34,21 +34,25 @@ #include #include "v9fs.h" #include "v9fs_vfs.h" +#include "cache.h" + +static DEFINE_SPINLOCK(v9fs_sessionlist_lock); +static LIST_HEAD(v9fs_sessionlist); /* - * Option Parsing (code inspired by NFS code) - * NOTE: each transport will parse its own options - */ + * Option Parsing (code inspired by NFS code) + * NOTE: each transport will parse its own options + */ enum { /* Options that take integer arguments */ Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid, /* String options */ - Opt_uname, Opt_remotename, Opt_trans, + Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag, /* Options that take no arguments */ Opt_nodevmap, /* Cache options */ - Opt_cache_loose, + Opt_cache_loose, Opt_fscache, /* Access options */ Opt_access, /* Error token */ @@ -63,8 +67,10 @@ static const match_table_t tokens = { {Opt_uname, "uname=%s"}, {Opt_remotename, "aname=%s"}, {Opt_nodevmap, "nodevmap"}, - {Opt_cache_loose, "cache=loose"}, + {Opt_cache, "cache=%s"}, {Opt_cache_loose, "loose"}, + {Opt_fscache, "fscache"}, + {Opt_cachetag, "cachetag=%s"}, {Opt_access, "access=%s"}, {Opt_err, NULL} }; @@ -89,16 +95,16 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts) v9ses->afid = ~0; v9ses->debug = 0; v9ses->cache = 0; +#ifdef CONFIG_9P_FSCACHE + v9ses->cachetag = NULL; +#endif if (!opts) return 0; options = kstrdup(opts, GFP_KERNEL); - if (!options) { - P9_DPRINTK(P9_DEBUG_ERROR, - "failed to allocate copy of option string\n"); - return -ENOMEM; - } + if (!options) + goto fail_option_alloc; while ((p = strsep(&options, ",")) != NULL) { int token; @@ -143,16 +149,33 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts) case Opt_cache_loose: v9ses->cache = CACHE_LOOSE; break; + case Opt_fscache: + v9ses->cache = CACHE_FSCACHE; + break; + case Opt_cachetag: +#ifdef CONFIG_9P_FSCACHE + v9ses->cachetag = match_strdup(&args[0]); +#endif + break; + case Opt_cache: + s = match_strdup(&args[0]); + if (!s) + goto fail_option_alloc; + + if (strcmp(s, "loose") == 0) + v9ses->cache = CACHE_LOOSE; + else if (strcmp(s, "fscache") == 0) + v9ses->cache = CACHE_FSCACHE; + else + v9ses->cache = CACHE_NONE; + kfree(s); + break; case Opt_access: s = match_strdup(&args[0]); - if (!s) { - P9_DPRINTK(P9_DEBUG_ERROR, - "failed to allocate copy" - " of option argument\n"); - ret = -ENOMEM; - break; - } + if (!s) + goto fail_option_alloc; + v9ses->flags &= ~V9FS_ACCESS_MASK; if (strcmp(s, "user") == 0) v9ses->flags |= V9FS_ACCESS_USER; @@ -173,6 +196,11 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts) } kfree(options); return ret; + +fail_option_alloc: + P9_DPRINTK(P9_DEBUG_ERROR, + "failed to allocate copy of option argument\n"); + return -ENOMEM; } /** @@ -249,6 +277,14 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses, else fid->uid = ~0; +#ifdef CONFIG_9P_FSCACHE + /* register the session for caching */ + v9fs_cache_session_get_cookie(v9ses); +#endif + + spin_lock(&v9fs_sessionlist_lock); + list_add(&v9ses->slist, &v9fs_sessionlist); + spin_unlock(&v9fs_sessionlist_lock); return fid; error: @@ -268,8 +304,16 @@ void v9fs_session_close(struct v9fs_session_info *v9ses) v9ses->clnt = NULL; } +#ifdef CONFIG_9P_FSCACHE + v9fs_cache_session_put_cookie(v9ses); + kfree(v9ses->cachetag); +#endif __putname(v9ses->uname); __putname(v9ses->aname); + + spin_lock(&v9fs_sessionlist_lock); + list_del(&v9ses->slist); + spin_unlock(&v9fs_sessionlist_lock); } /** @@ -286,25 +330,130 @@ void v9fs_session_cancel(struct v9fs_session_info *v9ses) { extern int v9fs_error_init(void); +static struct kobject *v9fs_kobj; + +#ifdef CONFIG_9P_FSCACHE /** - * v9fs_init - Initialize module + * caches_show - list caches associated with a session + * + * Returns the size of buffer written. + */ + +static ssize_t caches_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + ssize_t n = 0, count = 0, limit = PAGE_SIZE; + struct v9fs_session_info *v9ses; + + spin_lock(&v9fs_sessionlist_lock); + list_for_each_entry(v9ses, &v9fs_sessionlist, slist) { + n = snprintf(buf, limit, "%s\n", v9ses->cachetag); + if (n < 0) { + count = n; + break; + } + + count += n; + limit -= n; + } + + spin_unlock(&v9fs_sessionlist_lock); + return count; +} + +static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches); +#endif /* CONFIG_9P_FSCACHE */ + +static struct attribute *v9fs_attrs[] = { +#ifdef CONFIG_9P_FSCACHE + &v9fs_attr_cache.attr, +#endif + NULL, +}; + +static struct attribute_group v9fs_attr_group = { + .attrs = v9fs_attrs, +}; + +/** + * v9fs_sysfs_init - Initialize the v9fs sysfs interface + * + */ + +static int v9fs_sysfs_init(void) +{ + v9fs_kobj = kobject_create_and_add("9p", fs_kobj); + if (!v9fs_kobj) + return -ENOMEM; + + if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) { + kobject_put(v9fs_kobj); + return -ENOMEM; + } + + return 0; +} + +/** + * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface + * + */ + +static void v9fs_sysfs_cleanup(void) +{ + sysfs_remove_group(v9fs_kobj, &v9fs_attr_group); + kobject_put(v9fs_kobj); +} + +/** + * init_v9fs - Initialize module * */ static int __init init_v9fs(void) { + int err; printk(KERN_INFO "Installing v9fs 9p2000 file system support\n"); /* TODO: Setup list of registered trasnport modules */ - return register_filesystem(&v9fs_fs_type); + err = register_filesystem(&v9fs_fs_type); + if (err < 0) { + printk(KERN_ERR "Failed to register filesystem\n"); + return err; + } + + err = v9fs_cache_register(); + if (err < 0) { + printk(KERN_ERR "Failed to register v9fs for caching\n"); + goto out_fs_unreg; + } + + err = v9fs_sysfs_init(); + if (err < 0) { + printk(KERN_ERR "Failed to register with sysfs\n"); + goto out_sysfs_cleanup; + } + + return 0; + +out_sysfs_cleanup: + v9fs_sysfs_cleanup(); + +out_fs_unreg: + unregister_filesystem(&v9fs_fs_type); + + return err; } /** - * v9fs_init - shutdown module + * exit_v9fs - shutdown module * */ static void __exit exit_v9fs(void) { + v9fs_sysfs_cleanup(); + v9fs_cache_unregister(); unregister_filesystem(&v9fs_fs_type); } diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h index 38762bf..019f4cc 100644 --- a/fs/9p/v9fs.h +++ b/fs/9p/v9fs.h @@ -51,6 +51,7 @@ enum p9_session_flags { enum p9_cache_modes { CACHE_NONE, CACHE_LOOSE, + CACHE_FSCACHE, }; /** @@ -60,6 +61,8 @@ enum p9_cache_modes { * @debug: debug level * @afid: authentication handle * @cache: cache mode of type &p9_cache_modes + * @cachetag: the tag of the cache associated with this session + * @fscache: session cookie associated with FS-Cache * @options: copy of options string given by user * @uname: string user name to mount hierarchy as * @aname: mount specifier for remote hierarchy @@ -68,7 +71,7 @@ enum p9_cache_modes { * @dfltgid: default numeric groupid to mount hierarchy as * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy * @clnt: reference to 9P network client instantiated for this session - * @debugfs_dir: reference to debugfs_dir which can be used for add'l debug + * @slist: reference to list of registered 9p sessions * * This structure holds state for each session instance established during * a sys_mount() . @@ -84,6 +87,10 @@ struct v9fs_session_info { unsigned short debug; unsigned int afid; unsigned int cache; +#ifdef CONFIG_9P_FSCACHE + char *cachetag; + struct fscache_cookie *fscache; +#endif char *uname; /* user name to mount as */ char *aname; /* name of remote hierarchy being mounted */ @@ -92,11 +99,9 @@ struct v9fs_session_info { unsigned int dfltgid; /* default gid for legacy support */ u32 uid; /* if ACCESS_SINGLE, the uid that has access */ struct p9_client *clnt; /* 9p client */ - struct dentry *debugfs_dir; + struct list_head slist; /* list of sessions registered with v9fs */ }; -extern struct dentry *v9fs_debugfs_root; - struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *, char *); void v9fs_session_close(struct v9fs_session_info *v9ses); diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h index f0c7de7..3a7560e 100644 --- a/fs/9p/v9fs_vfs.h +++ b/fs/9p/v9fs_vfs.h @@ -44,7 +44,13 @@ extern const struct file_operations v9fs_dir_operations; extern const struct dentry_operations v9fs_dentry_operations; extern const struct dentry_operations v9fs_cached_dentry_operations; +#ifdef CONFIG_9P_FSCACHE +struct inode *v9fs_alloc_inode(struct super_block *sb); +void v9fs_destroy_inode(struct inode *inode); +#endif + struct inode *v9fs_get_inode(struct super_block *sb, int mode); +void v9fs_clear_inode(struct inode *inode); ino_t v9fs_qid2ino(struct p9_qid *qid); void v9fs_stat2inode(struct p9_wstat *, struct inode *, struct super_block *); int v9fs_dir_release(struct inode *inode, struct file *filp); diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c index 9282828..90e3844 100644 --- a/fs/9p/vfs_addr.c +++ b/fs/9p/vfs_addr.c @@ -38,6 +38,7 @@ #include "v9fs.h" #include "v9fs_vfs.h" +#include "cache.h" /** * v9fs_vfs_readpage - read an entire page in from 9P @@ -52,18 +53,31 @@ static int v9fs_vfs_readpage(struct file *filp, struct page *page) int retval; loff_t offset; char *buffer; + struct inode *inode; + inode = page->mapping->host; P9_DPRINTK(P9_DEBUG_VFS, "\n"); + + BUG_ON(!PageLocked(page)); + + retval = v9fs_readpage_from_fscache(inode, page); + if (retval == 0) + return retval; + buffer = kmap(page); offset = page_offset(page); retval = v9fs_file_readn(filp, buffer, NULL, PAGE_CACHE_SIZE, offset); - if (retval < 0) + if (retval < 0) { + v9fs_uncache_page(inode, page); goto done; + } memset(buffer + retval, 0, PAGE_CACHE_SIZE - retval); flush_dcache_page(page); SetPageUptodate(page); + + v9fs_readpage_to_fscache(inode, page); retval = 0; done: @@ -72,6 +86,78 @@ done: return retval; } +/** + * v9fs_vfs_readpages - read a set of pages from 9P + * + * @filp: file being read + * @mapping: the address space + * @pages: list of pages to read + * @nr_pages: count of pages to read + * + */ + +static int v9fs_vfs_readpages(struct file *filp, struct address_space *mapping, + struct list_head *pages, unsigned nr_pages) +{ + int ret = 0; + struct inode *inode; + + inode = mapping->host; + P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, filp); + + ret = v9fs_readpages_from_fscache(inode, mapping, pages, &nr_pages); + if (ret == 0) + return ret; + + ret = read_cache_pages(mapping, pages, (void *)v9fs_vfs_readpage, filp); + P9_DPRINTK(P9_DEBUG_VFS, " = %d\n", ret); + return ret; +} + +/** + * v9fs_release_page - release the private state associated with a page + * + * Returns 1 if the page can be released, false otherwise. + */ + +static int v9fs_release_page(struct page *page, gfp_t gfp) +{ + if (PagePrivate(page)) + return 0; + + return v9fs_fscache_release_page(page, gfp); +} + +/** + * v9fs_invalidate_page - Invalidate a page completely or partially + * + * @page: structure to page + * @offset: offset in the page + */ + +static void v9fs_invalidate_page(struct page *page, unsigned long offset) +{ + if (offset == 0) + v9fs_fscache_invalidate_page(page); +} + +/** + * v9fs_launder_page - Writeback a dirty page + * Since the writes go directly to the server, we simply return a 0 + * here to indicate success. + * + * Returns 0 on success. + */ + +static int v9fs_launder_page(struct page *page) +{ + return 0; +} + const struct address_space_operations v9fs_addr_operations = { .readpage = v9fs_vfs_readpage, + .readpages = v9fs_vfs_readpages, + .releasepage = v9fs_release_page, + .invalidatepage = v9fs_invalidate_page, + .launder_page = v9fs_launder_page, }; diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index cafaa46..3902bf4 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -41,6 +41,7 @@ #include "v9fs.h" #include "v9fs_vfs.h" #include "fid.h" +#include "cache.h" static const struct file_operations v9fs_cached_file_operations; @@ -86,6 +87,10 @@ int v9fs_file_open(struct inode *inode, struct file *file) /* enable cached file options */ if(file->f_op == &v9fs_file_operations) file->f_op = &v9fs_cached_file_operations; + +#ifdef CONFIG_9P_FSCACHE + v9fs_cache_inode_set_cookie(inode, file); +#endif } return 0; @@ -238,8 +243,9 @@ v9fs_file_write(struct file *filp, const char __user * data, if (total > 0) { pg_start = origin >> PAGE_CACHE_SHIFT; pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT; - invalidate_inode_pages2_range(inode->i_mapping, pg_start, - pg_end); + if (inode->i_mapping && inode->i_mapping->nrpages) + invalidate_inode_pages2_range(inode->i_mapping, + pg_start, pg_end); *offset += total; i_size_write(inode, i_size_read(inode) + total); inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9; diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index f3bfa87..6a0af65 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -40,6 +40,7 @@ #include "v9fs.h" #include "v9fs_vfs.h" #include "fid.h" +#include "cache.h" static const struct inode_operations v9fs_dir_inode_operations; static const struct inode_operations v9fs_dir_inode_operations_ext; @@ -197,6 +198,38 @@ v9fs_blank_wstat(struct p9_wstat *wstat) wstat->extension = NULL; } +#ifdef CONFIG_9P_FSCACHE +/** + * v9fs_alloc_inode - helper function to allocate an inode + * This callback is executed before setting up the inode so that we + * can associate a vcookie with each inode. + * + */ + +struct inode *v9fs_alloc_inode(struct super_block *sb) +{ + struct v9fs_cookie *vcookie; + vcookie = (struct v9fs_cookie *)kmem_cache_alloc(vcookie_cache, + GFP_KERNEL); + if (!vcookie) + return NULL; + + vcookie->fscache = NULL; + vcookie->qid = NULL; + return &vcookie->inode; +} + +/** + * v9fs_destroy_inode - destroy an inode + * + */ + +void v9fs_destroy_inode(struct inode *inode) +{ + kmem_cache_free(vcookie_cache, v9fs_inode2cookie(inode)); +} +#endif + /** * v9fs_get_inode - helper function to setup an inode * @sb: superblock @@ -326,6 +359,21 @@ error: } */ + +/** + * v9fs_clear_inode - release an inode + * @inode: inode to release + * + */ +void v9fs_clear_inode(struct inode *inode) +{ + filemap_fdatawrite(inode->i_mapping); + +#ifdef CONFIG_9P_FSCACHE + v9fs_cache_inode_put_cookie(inode); +#endif +} + /** * v9fs_inode_from_fid - populate an inode by issuing a attribute request * @v9ses: session information @@ -356,8 +404,14 @@ v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid, v9fs_stat2inode(st, ret, sb); ret->i_ino = v9fs_qid2ino(&st->qid); + v9fs_vcookie_set_qid(ret, &st->qid); + +#ifdef CONFIG_9P_FSCACHE + v9fs_cache_inode_get_cookie(ret); +#endif p9stat_free(st); kfree(st); + return ret; error: @@ -751,7 +805,7 @@ v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry); err = -EPERM; v9ses = v9fs_inode2v9ses(dentry->d_inode); - if (v9ses->cache == CACHE_LOOSE) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) return simple_getattr(mnt, dentry, stat); fid = v9fs_fid_lookup(dentry); diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c index 8961f1a..14a8644 100644 --- a/fs/9p/vfs_super.c +++ b/fs/9p/vfs_super.c @@ -44,21 +44,9 @@ #include "v9fs_vfs.h" #include "fid.h" -static void v9fs_clear_inode(struct inode *); static const struct super_operations v9fs_super_ops; /** - * v9fs_clear_inode - release an inode - * @inode: inode to release - * - */ - -static void v9fs_clear_inode(struct inode *inode) -{ - filemap_fdatawrite(inode->i_mapping); -} - -/** * v9fs_set_super - set the superblock * @s: super block * @data: file system specific data @@ -220,6 +208,10 @@ v9fs_umount_begin(struct super_block *sb) } static const struct super_operations v9fs_super_ops = { +#ifdef CONFIG_9P_FSCACHE + .alloc_inode = v9fs_alloc_inode, + .destroy_inode = v9fs_destroy_inode, +#endif .statfs = simple_statfs, .clear_inode = v9fs_clear_inode, .show_options = generic_show_options, diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h index b77c147..a7fb548 100644 --- a/include/net/9p/9p.h +++ b/include/net/9p/9p.h @@ -38,6 +38,8 @@ * @P9_DEBUG_SLABS: memory management tracing * @P9_DEBUG_FCALL: verbose dump of protocol messages * @P9_DEBUG_FID: fid allocation/deallocation tracking + * @P9_DEBUG_PKT: packet marshalling/unmarshalling + * @P9_DEBUG_FSC: FS-cache tracing * * These flags are passed at mount time to turn on various levels of * verbosity and tracing which will be output to the system logs. @@ -54,6 +56,7 @@ enum p9_debug_flags { P9_DEBUG_FCALL = (1<<8), P9_DEBUG_FID = (1<<9), P9_DEBUG_PKT = (1<<10), + P9_DEBUG_FSC = (1<<11), }; #ifdef CONFIG_NET_9P_DEBUG