/* * Retrieve a set of pages from fscache */ int __nfs_readpages_from_fscache(struct nfs_open_context *ctx, struct inode *inode, struct address_space *mapping, struct list_head *pages, unsigned *nr_pages) { int ret, npages = *nr_pages; dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache (0x%p/%u/0x%p)\n", NFS_I(inode)->fscache, npages, inode); ret = fscache_read_or_alloc_pages(NFS_I(inode)->fscache, mapping, pages, nr_pages, nfs_readpage_from_fscache_complete, ctx, mapping_gfp_mask(mapping)); if (*nr_pages < npages) nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK, npages); if (*nr_pages > 0) nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL, *nr_pages); switch (ret) { case 0: /* read submitted to the cache for all pages */ BUG_ON(!list_empty(pages)); BUG_ON(*nr_pages != 0); dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache: submitted\n"); return ret; case -ENOBUFS: /* some pages aren't cached and can't be */ case -ENODATA: /* some pages aren't cached */ dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache: no page: %d\n", ret); return 1; default: dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache: ret %d\n", ret); } return ret; }
/* * Store a newly fetched page in fscache * - PG_fscache must be set on the page */ void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync) { int ret; // dfprintk(FSCACHE, // "NFS: readpage_to_fscache(fsc:%p/p:%p(i:%lx f:%lx)/%d)\n", ; ret = fscache_write_page(NFS_I(inode)->fscache, page, GFP_KERNEL); // dfprintk(FSCACHE, // "NFS: readpage_to_fscache: p:%p(i:%lu f:%lx) ret %d\n", ; if (ret != 0) { fscache_uncache_page(NFS_I(inode)->fscache, page); nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL, 1); nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED, 1); } else { nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_WRITTEN_OK, 1); } }
/* * Release the caching state associated with a page if undergoing complete page * invalidation. */ void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode) { struct nfs_inode *nfsi = NFS_I(inode); struct fscache_cookie *cookie = nfsi->fscache; BUG_ON(!cookie); // dfprintk(FSCACHE, "NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n", ; fscache_wait_on_page_write(cookie, page); BUG_ON(!PageLocked(page)); fscache_uncache_page(cookie, page); nfs_add_fscache_stats(page->mapping->host, NFSIOS_FSCACHE_PAGES_UNCACHED, 1); }
/* * Release the caching state associated with a page, if the page isn't busy * interacting with the cache. * - Returns true (can release page) or false (page busy). */ int nfs_fscache_release_page(struct page *page, gfp_t gfp) { if (PageFsCache(page)) { struct nfs_inode *nfsi = NFS_I(page->mapping->host); struct fscache_cookie *cookie = nfsi->fscache; BUG_ON(!cookie); // dfprintk(FSCACHE, "NFS: fscache releasepage (0x%p/0x%p/0x%p)\n", ; if (!fscache_maybe_release_page(cookie, page, gfp)) return 0; nfs_add_fscache_stats(page->mapping->host, NFSIOS_FSCACHE_PAGES_UNCACHED, 1); } return 1; }