diff options
Diffstat (limited to '')
-rw-r--r-- | fs/9p/cache.c | 338 |
1 files changed, 37 insertions, 301 deletions
diff --git a/fs/9p/cache.c b/fs/9p/cache.c index eb2151fb6049..cebba4eaa0b5 100644 --- a/fs/9p/cache.c +++ b/fs/9p/cache.c @@ -16,323 +16,59 @@ #include "v9fs.h" #include "cache.h" -#define CACHETAG_LEN 11 - -struct fscache_netfs v9fs_cache_netfs = { - .name = "9p", - .version = 0, -}; - -/** - * 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) +int v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses, + const char *dev_name) { - v9ses->cachetag = kmalloc(CACHETAG_LEN, GFP_KERNEL); - if (!v9ses->cachetag) - return -ENOMEM; - - return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies); -} + struct fscache_volume *vcookie; + char *name, *p; -const struct fscache_cookie_def v9fs_cache_session_index_def = { - .name = "9P.session", - .type = FSCACHE_COOKIE_TYPE_INDEX, -}; + name = kasprintf(GFP_KERNEL, "9p,%s,%s", + dev_name, v9ses->cachetag ?: v9ses->aname); + if (!name) + return -ENOMEM; -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) { - if (v9fs_random_cachetag(v9ses) < 0) { - v9ses->fscache = NULL; - kfree(v9ses->cachetag); - v9ses->cachetag = NULL; - return; + for (p = name; *p; p++) + if (*p == '/') + *p = ';'; + + vcookie = fscache_acquire_volume(name, NULL, NULL, 0); + p9_debug(P9_DEBUG_FSC, "session %p get volume %p (%s)\n", + v9ses, vcookie, name); + if (IS_ERR(vcookie)) { + if (vcookie != ERR_PTR(-EBUSY)) { + kfree(name); + return PTR_ERR(vcookie); } + pr_err("Cache volume key already in use (%s)\n", name); + vcookie = NULL; } - - v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index, - &v9fs_cache_session_index_def, - v9ses->cachetag, - strlen(v9ses->cachetag), - NULL, 0, - v9ses, 0, true); - p9_debug(P9_DEBUG_FSC, "session %p get cookie %p\n", - v9ses, v9ses->fscache); -} - -void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses) -{ - p9_debug(P9_DEBUG_FSC, "session %p put cookie %p\n", - v9ses, v9ses->fscache); - fscache_relinquish_cookie(v9ses->fscache, NULL, false); - v9ses->fscache = NULL; + v9ses->fscache = vcookie; + kfree(name); + return 0; } -static enum -fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data, - const void *buffer, - uint16_t buflen, - loff_t object_size) -{ - const struct v9fs_inode *v9inode = cookie_netfs_data; - - if (buflen != sizeof(v9inode->qid.version)) - return FSCACHE_CHECKAUX_OBSOLETE; - - if (memcmp(buffer, &v9inode->qid.version, - sizeof(v9inode->qid.version))) - return FSCACHE_CHECKAUX_OBSOLETE; - - return FSCACHE_CHECKAUX_OKAY; -} - -const struct fscache_cookie_def v9fs_cache_inode_index_def = { - .name = "9p.inode", - .type = FSCACHE_COOKIE_TYPE_DATAFILE, - .check_aux = v9fs_cache_inode_check_aux, -}; - void v9fs_cache_inode_get_cookie(struct inode *inode) { - struct v9fs_inode *v9inode; + struct v9fs_inode *v9inode = V9FS_I(inode); struct v9fs_session_info *v9ses; + __le32 version; + __le64 path; if (!S_ISREG(inode->i_mode)) return; - - v9inode = V9FS_I(inode); - if (v9inode->fscache) + if (WARN_ON(v9fs_inode_cookie(v9inode))) return; + version = cpu_to_le32(v9inode->qid.version); + path = cpu_to_le64(v9inode->qid.path); v9ses = v9fs_inode2v9ses(inode); - v9inode->fscache = fscache_acquire_cookie(v9ses->fscache, - &v9fs_cache_inode_index_def, - &v9inode->qid.path, - sizeof(v9inode->qid.path), - &v9inode->qid.version, - sizeof(v9inode->qid.version), - v9inode, - i_size_read(&v9inode->vfs_inode), - true); + v9inode->netfs.cache = + fscache_acquire_cookie(v9fs_session_cache(v9ses), + 0, + &path, sizeof(path), + &version, sizeof(version), + i_size_read(&v9inode->netfs.inode)); p9_debug(P9_DEBUG_FSC, "inode %p get cookie %p\n", - inode, v9inode->fscache); -} - -void v9fs_cache_inode_put_cookie(struct inode *inode) -{ - struct v9fs_inode *v9inode = V9FS_I(inode); - - if (!v9inode->fscache) - return; - p9_debug(P9_DEBUG_FSC, "inode %p put cookie %p\n", - inode, v9inode->fscache); - - fscache_relinquish_cookie(v9inode->fscache, &v9inode->qid.version, - false); - v9inode->fscache = NULL; -} - -void v9fs_cache_inode_flush_cookie(struct inode *inode) -{ - struct v9fs_inode *v9inode = V9FS_I(inode); - - if (!v9inode->fscache) - return; - p9_debug(P9_DEBUG_FSC, "inode %p flush cookie %p\n", - inode, v9inode->fscache); - - fscache_relinquish_cookie(v9inode->fscache, NULL, true); - v9inode->fscache = NULL; -} - -void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp) -{ - struct v9fs_inode *v9inode = V9FS_I(inode); - - if (!v9inode->fscache) - return; - - mutex_lock(&v9inode->fscache_lock); - - if ((filp->f_flags & O_ACCMODE) != O_RDONLY) - v9fs_cache_inode_flush_cookie(inode); - else - v9fs_cache_inode_get_cookie(inode); - - mutex_unlock(&v9inode->fscache_lock); -} - -void v9fs_cache_inode_reset_cookie(struct inode *inode) -{ - struct v9fs_inode *v9inode = V9FS_I(inode); - struct v9fs_session_info *v9ses; - struct fscache_cookie *old; - - if (!v9inode->fscache) - return; - - old = v9inode->fscache; - - mutex_lock(&v9inode->fscache_lock); - fscache_relinquish_cookie(v9inode->fscache, NULL, true); - - v9ses = v9fs_inode2v9ses(inode); - v9inode->fscache = fscache_acquire_cookie(v9ses->fscache, - &v9fs_cache_inode_index_def, - &v9inode->qid.path, - sizeof(v9inode->qid.path), - &v9inode->qid.version, - sizeof(v9inode->qid.version), - v9inode, - i_size_read(&v9inode->vfs_inode), - true); - p9_debug(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p\n", - inode, old, v9inode->fscache); - - mutex_unlock(&v9inode->fscache_lock); -} - -int __v9fs_fscache_release_page(struct page *page, gfp_t gfp) -{ - struct inode *inode = page->mapping->host; - struct v9fs_inode *v9inode = V9FS_I(inode); - - BUG_ON(!v9inode->fscache); - - return fscache_maybe_release_page(v9inode->fscache, page, gfp); -} - -void __v9fs_fscache_invalidate_page(struct page *page) -{ - struct inode *inode = page->mapping->host; - struct v9fs_inode *v9inode = V9FS_I(inode); - - BUG_ON(!v9inode->fscache); - - if (PageFsCache(page)) { - fscache_wait_on_page_write(v9inode->fscache, page); - BUG_ON(!PageLocked(page)); - fscache_uncache_page(v9inode->fscache, 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_inode *v9inode = V9FS_I(inode); - - p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page); - if (!v9inode->fscache) - return -ENOBUFS; - - ret = fscache_read_or_alloc_page(v9inode->fscache, - page, - v9fs_vfs_readpage_complete, - NULL, - GFP_KERNEL); - switch (ret) { - case -ENOBUFS: - case -ENODATA: - p9_debug(P9_DEBUG_FSC, "page/inode not in cache %d\n", ret); - return 1; - case 0: - p9_debug(P9_DEBUG_FSC, "BIO submitted\n"); - return ret; - default: - p9_debug(P9_DEBUG_FSC, "ret %d\n", 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_inode *v9inode = V9FS_I(inode); - - p9_debug(P9_DEBUG_FSC, "inode %p pages %u\n", inode, *nr_pages); - if (!v9inode->fscache) - return -ENOBUFS; - - ret = fscache_read_or_alloc_pages(v9inode->fscache, - mapping, pages, nr_pages, - v9fs_vfs_readpage_complete, - NULL, - mapping_gfp_mask(mapping)); - switch (ret) { - case -ENOBUFS: - case -ENODATA: - p9_debug(P9_DEBUG_FSC, "pages/inodes not in cache %d\n", ret); - return 1; - case 0: - BUG_ON(!list_empty(pages)); - BUG_ON(*nr_pages != 0); - p9_debug(P9_DEBUG_FSC, "BIO submitted\n"); - return ret; - default: - p9_debug(P9_DEBUG_FSC, "ret %d\n", 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_inode *v9inode = V9FS_I(inode); - - p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page); - ret = fscache_write_page(v9inode->fscache, page, - i_size_read(&v9inode->vfs_inode), GFP_KERNEL); - p9_debug(P9_DEBUG_FSC, "ret = %d\n", ret); - if (ret != 0) - v9fs_uncache_page(inode, page); -} - -/* - * wait for a page to complete writing to the cache - */ -void __v9fs_fscache_wait_on_page_write(struct inode *inode, struct page *page) -{ - const struct v9fs_inode *v9inode = V9FS_I(inode); - p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page); - if (PageFsCache(page)) - fscache_wait_on_page_write(v9inode->fscache, page); + inode, v9fs_inode_cookie(v9inode)); } |