From 91b467e0a3f5fa861265eda94640b7d4c0290551 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 5 Jan 2017 10:38:35 +0000 Subject: [PATCH] afs: Make afs_readpages() fetch data in bulk Make afs_readpages() use afs_vnode_fetch_data()'s new ability to take a list of pages and do a bulk fetch. Signed-off-by: David Howells --- fs/afs/file.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++- fs/afs/volume.c | 1 + 2 files changed, 130 insertions(+), 2 deletions(-) diff --git a/fs/afs/file.c b/fs/afs/file.c index 6c262ceef32d..82897a78abc7 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -16,6 +16,7 @@ #include #include #include +#include #include "internal.h" static int afs_readpage(struct file *file, struct page *page); @@ -261,6 +262,129 @@ static int afs_readpage(struct file *file, struct page *page) return ret; } +/* + * Make pages available as they're filled. + */ +static void afs_readpages_page_done(struct afs_call *call, struct afs_read *req) +{ + struct afs_vnode *vnode = call->reply; + struct page *page = req->pages[req->index]; + + req->pages[req->index] = NULL; + SetPageUptodate(page); + + /* send the page to the cache */ +#ifdef CONFIG_AFS_FSCACHE + if (PageFsCache(page) && + fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) { + fscache_uncache_page(vnode->cache, page); + BUG_ON(PageFsCache(page)); + } +#endif + unlock_page(page); + put_page(page); +} + +/* + * Read a contiguous set of pages. + */ +static int afs_readpages_one(struct file *file, struct address_space *mapping, + struct list_head *pages) +{ + struct afs_vnode *vnode = AFS_FS_I(mapping->host); + struct afs_read *req; + struct list_head *p; + struct page *first, *page; + struct key *key = file->private_data; + pgoff_t index; + int ret, n, i; + + /* Count the number of contiguous pages at the front of the list. Note + * that the list goes prev-wards rather than next-wards. + */ + first = list_entry(pages->prev, struct page, lru); + index = first->index + 1; + n = 1; + for (p = first->lru.prev; p != pages; p = p->prev) { + page = list_entry(p, struct page, lru); + if (page->index != index) + break; + index++; + n++; + } + + req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *) * n, + GFP_NOFS); + if (!req) + return -ENOMEM; + + atomic_set(&req->usage, 1); + req->page_done = afs_readpages_page_done; + req->pos = first->index; + req->pos <<= PAGE_SHIFT; + + /* Transfer the pages to the request. We add them in until one fails + * to add to the LRU and then we stop (as that'll make a hole in the + * contiguous run. + * + * Note that it's possible for the file size to change whilst we're + * doing this, but we rely on the server returning less than we asked + * for if the file shrank. We also rely on this to deal with a partial + * page at the end of the file. + */ + do { + page = list_entry(pages->prev, struct page, lru); + list_del(&page->lru); + index = page->index; + if (add_to_page_cache_lru(page, mapping, index, + readahead_gfp_mask(mapping))) { +#ifdef CONFIG_AFS_FSCACHE + fscache_uncache_page(vnode->cache, page); +#endif + put_page(page); + break; + } + + req->pages[req->nr_pages++] = page; + req->len += PAGE_SIZE; + } while (req->nr_pages < n); + + if (req->nr_pages == 0) { + kfree(req); + return 0; + } + + ret = afs_vnode_fetch_data(vnode, key, req); + if (ret < 0) + goto error; + + task_io_account_read(PAGE_SIZE * req->nr_pages); + afs_put_read(req); + return 0; + +error: + if (ret == -ENOENT) { + _debug("got NOENT from server" + " - marking file deleted and stale"); + set_bit(AFS_VNODE_DELETED, &vnode->flags); + ret = -ESTALE; + } + + for (i = 0; i < req->nr_pages; i++) { + page = req->pages[i]; + if (page) { +#ifdef CONFIG_AFS_FSCACHE + fscache_uncache_page(vnode->cache, page); +#endif + SetPageError(page); + unlock_page(page); + } + } + + afs_put_read(req); + return ret; +} + /* * read a set of pages */ @@ -314,8 +438,11 @@ static int afs_readpages(struct file *file, struct address_space *mapping, return ret; } - /* load the missing pages from the network */ - ret = read_cache_pages(mapping, pages, afs_page_filler, key); + while (!list_empty(pages)) { + ret = afs_readpages_one(file, mapping, pages); + if (ret < 0) + break; + } _leave(" = %d [netting]", ret); return ret; diff --git a/fs/afs/volume.c b/fs/afs/volume.c index d142a2449e65..546f9d01710b 100644 --- a/fs/afs/volume.c +++ b/fs/afs/volume.c @@ -106,6 +106,7 @@ struct afs_volume *afs_volume_lookup(struct afs_mount_params *params) volume->cell = params->cell; volume->vid = vlocation->vldb.vid[params->type]; + volume->bdi.ra_pages = VM_MAX_READAHEAD*1024/PAGE_SIZE; ret = bdi_setup_and_register(&volume->bdi, "afs"); if (ret) goto error_bdi; -- 2.20.1