Return-Path: linux-nfs-owner@vger.kernel.org Received: from casper.infradead.org ([85.118.1.10]:45793 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754217AbaHGHVq (ORCPT ); Thu, 7 Aug 2014 03:21:46 -0400 From: Christoph Hellwig To: Trond Myklebust Cc: linux-nfs@vger.kernel.org Subject: [PATCH 17/17] pnfs/blocklayout: allocate separate pages for the layoutcommit payload Date: Thu, 7 Aug 2014 09:23:49 +0200 Message-Id: <1407396229-4785-18-git-send-email-hch@lst.de> In-Reply-To: <1407396229-4785-1-git-send-email-hch@lst.de> References: <1407396229-4785-1-git-send-email-hch@lst.de> Sender: linux-nfs-owner@vger.kernel.org List-ID: Instead of overflowing the XDR send buffer with our extent list allocate pages and pre-encode the layoutupdate payload into them. We optimistically allocate a single page use alloc_page and only switch to vmalloc when we have more extents outstanding. Currently there is only a single testcase (xfstests generic/113) which can reproduce large enough extent lists for this to occur. Signed-off-by: Christoph Hellwig --- fs/nfs/blocklayout/blocklayout.c | 9 ++-- fs/nfs/blocklayout/blocklayout.h | 6 ++- fs/nfs/blocklayout/extent_tree.c | 89 +++++++++++++++++++++++++++++++--------- 3 files changed, 78 insertions(+), 26 deletions(-) diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index d5a2b87..fae8144 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -498,12 +498,11 @@ bl_return_range(struct pnfs_layout_hdr *lo, err = ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end); } -static void -bl_encode_layoutcommit(struct pnfs_layout_hdr *lo, struct xdr_stream *xdr, - const struct nfs4_layoutcommit_args *arg) +static int +bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg) { dprintk("%s enter\n", __func__); - ext_tree_encode_commit(BLK_LO2EXT(lo), xdr); + return ext_tree_prepare_commit(arg); } static void @@ -808,7 +807,7 @@ static struct pnfs_layoutdriver_type blocklayout_type = { .alloc_lseg = bl_alloc_lseg, .free_lseg = bl_free_lseg, .return_range = bl_return_range, - .encode_layoutcommit = bl_encode_layoutcommit, + .prepare_layoutcommit = bl_prepare_layoutcommit, .cleanup_layoutcommit = bl_cleanup_layoutcommit, .set_layoutdriver = bl_set_layoutdriver, .clear_layoutdriver = bl_clear_layoutdriver, diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h index b4f66d8..caae202 100644 --- a/fs/nfs/blocklayout/blocklayout.h +++ b/fs/nfs/blocklayout/blocklayout.h @@ -80,6 +80,9 @@ struct pnfs_block_extent { unsigned int be_tag; }; +/* on the wire size of the extent */ +#define BL_EXTENT_SIZE (7 * sizeof(__be32) + NFS4_DEVICEID4_SIZE) + struct pnfs_block_layout { struct pnfs_layout_hdr bl_layout; struct rb_root bl_ext_rw; @@ -138,8 +141,7 @@ int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start, sector_t len); bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect, struct pnfs_block_extent *ret, bool rw); -int ext_tree_encode_commit(struct pnfs_block_layout *bl, - struct xdr_stream *xdr); +int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg); void ext_tree_mark_committed(struct pnfs_block_layout *bl, int status); #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */ diff --git a/fs/nfs/blocklayout/extent_tree.c b/fs/nfs/blocklayout/extent_tree.c index c7dacfa..3945221 100644 --- a/fs/nfs/blocklayout/extent_tree.c +++ b/fs/nfs/blocklayout/extent_tree.c @@ -465,32 +465,23 @@ out: return err; } -int -ext_tree_encode_commit(struct pnfs_block_layout *bl, struct xdr_stream *xdr) +static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p, + size_t buffer_size, size_t *count) { struct pnfs_block_extent *be; - unsigned int count = 0; - __be32 *p, *xdr_start; int ret = 0; - dprintk("%s enter\n", __func__); - - xdr_start = xdr_reserve_space(xdr, 8); - if (!xdr_start) - return -ENOSPC; - spin_lock(&bl->bl_ext_lock); for (be = ext_tree_first(&bl->bl_ext_rw); be; be = ext_tree_next(be)) { if (be->be_state != PNFS_BLOCK_INVALID_DATA || be->be_tag != EXTENT_WRITTEN) continue; - p = xdr_reserve_space(xdr, 7 * sizeof(__be32) + - NFS4_DEVICEID4_SIZE); - if (!p) { - printk("%s: out of space for extent list\n", __func__); + (*count)++; + if (*count * BL_EXTENT_SIZE > buffer_size) { + /* keep counting.. */ ret = -ENOSPC; - break; + continue; } p = xdr_encode_opaque_fixed(p, be->be_devid.data, @@ -501,15 +492,75 @@ ext_tree_encode_commit(struct pnfs_block_layout *bl, struct xdr_stream *xdr) *p++ = cpu_to_be32(PNFS_BLOCK_READWRITE_DATA); be->be_tag = EXTENT_COMMITTING; - count++; } spin_unlock(&bl->bl_ext_lock); - xdr_start[0] = cpu_to_be32((xdr->p - xdr_start - 1) * 4); - xdr_start[1] = cpu_to_be32(count); + return ret; +} + +int +ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg) +{ + struct pnfs_block_layout *bl = BLK_LO2EXT(NFS_I(arg->inode)->layout); + size_t count = 0, buffer_size = PAGE_SIZE; + __be32 *start_p; + int ret; + + dprintk("%s enter\n", __func__); + + arg->layoutupdate_page = alloc_page(GFP_NOFS); + if (!arg->layoutupdate_page) + return -ENOMEM; + start_p = page_address(arg->layoutupdate_page); + arg->layoutupdate_pages = &arg->layoutupdate_page; + +retry: + ret = ext_tree_encode_commit(bl, start_p + 1, buffer_size, &count); + if (unlikely(ret)) { + if (arg->layoutupdate_pages != &arg->layoutupdate_page) { + int nr_pages = DIV_ROUND_UP(buffer_size, PAGE_SIZE), i; + + for (i = 0; i < nr_pages; i++) + put_page(arg->layoutupdate_pages[i]); + kfree(arg->layoutupdate_pages); + } else { + put_page(arg->layoutupdate_page); + } + + buffer_size = sizeof(__be32) + BL_EXTENT_SIZE * count; + count = 0; + + arg->layoutupdate_pages = + kcalloc(DIV_ROUND_UP(buffer_size, PAGE_SIZE), + sizeof(struct page *), GFP_NOFS); + if (!arg->layoutupdate_pages) + return -ENOMEM; + + start_p = __vmalloc(buffer_size, GFP_NOFS, PAGE_KERNEL); + if (!start_p) { + kfree(arg->layoutupdate_pages); + return -ENOMEM; + } + + goto retry; + } + + *start_p = cpu_to_be32(count); + arg->layoutupdate_len = sizeof(__be32) + BL_EXTENT_SIZE * count; + + if (unlikely(arg->layoutupdate_pages != &arg->layoutupdate_page)) { + __be32 *p = start_p; + int i = 0; + + for (p = start_p; + p < start_p + arg->layoutupdate_len; + p += PAGE_SIZE) { + arg->layoutupdate_pages[i++] = vmalloc_to_page(p); + } + } dprintk("%s found %i ranges\n", __func__, count); - return ret; + return 0; } void -- 1.9.1