From 6c4fe19f66a839bce68fcb7b99cdcb0f31c7a59e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 11 Jan 2006 20:49:28 +1100 Subject: [XFS] cluster rewrites We can cluster mapped pages aswell, this improves performances on rewrites since we can reduce the number of allocator calls. SGI-PV: 947118 SGI-Modid: xfs-linux-melb:xfs-kern:203829a Signed-off-by: Christoph Hellwig Signed-off-by: Nathan Scott --- fs/xfs/linux-2.6/xfs_aops.c | 63 +++++++++++++++++++++++++++++++++------------ 1 file changed, 47 insertions(+), 16 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 562867316639a..9ea33ea6a2257 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -470,13 +470,13 @@ xfs_map_at_offset( } /* - * Look for a page at index which is unlocked and not mapped - * yet - clustering for mmap write case. + * Look for a page at index that is suitable for clustering. */ STATIC unsigned int -xfs_probe_unmapped_page( +xfs_probe_page( struct page *page, - unsigned int pg_offset) + unsigned int pg_offset, + int mapped) { int ret = 0; @@ -489,25 +489,28 @@ xfs_probe_unmapped_page( bh = head = page_buffers(page); do { - if (buffer_mapped(bh) || !buffer_uptodate(bh)) + if (!buffer_uptodate(bh)) + break; + if (mapped != buffer_mapped(bh)) break; ret += bh->b_size; if (ret >= pg_offset) break; } while ((bh = bh->b_this_page) != head); } else - ret = PAGE_CACHE_SIZE; + ret = mapped ? 0 : PAGE_CACHE_SIZE; } return ret; } STATIC size_t -xfs_probe_unmapped_cluster( +xfs_probe_cluster( struct inode *inode, struct page *startpage, struct buffer_head *bh, - struct buffer_head *head) + struct buffer_head *head, + int mapped) { struct pagevec pvec; pgoff_t tindex, tlast, tloff; @@ -516,7 +519,7 @@ xfs_probe_unmapped_cluster( /* First sum forwards in this page */ do { - if (buffer_mapped(bh)) + if (mapped != buffer_mapped(bh)) return total; total += bh->b_size; } while ((bh = bh->b_this_page) != head); @@ -550,7 +553,7 @@ xfs_probe_unmapped_cluster( pg_offset = PAGE_CACHE_SIZE; if (page->index == tindex && !TestSetPageLocked(page)) { - len = xfs_probe_unmapped_page(page, pg_offset); + len = xfs_probe_page(page, pg_offset, mapped); unlock_page(page); } @@ -592,6 +595,8 @@ xfs_is_delayed_page( acceptable = (type == IOMAP_UNWRITTEN); else if (buffer_delay(bh)) acceptable = (type == IOMAP_DELAY); + else if (buffer_mapped(bh)) + acceptable = (type == 0); else break; } while ((bh = bh->b_this_page) != head); @@ -804,6 +809,7 @@ xfs_page_state_convert( ssize_t size, len; int flags, err, iomap_valid = 0, uptodate = 1; int page_dirty, count = 0, trylock_flag = 0; + int all_bh = unmapped; /* wait for other IO threads? */ if (startio && wbc->sync_mode != WB_SYNC_NONE) @@ -845,6 +851,8 @@ xfs_page_state_convert( bh = head = page_buffers(page); offset = page_offset(page); + flags = -1; + type = 0; /* TODO: cleanup count and page_dirty */ @@ -878,6 +886,12 @@ xfs_page_state_convert( if (buffer_unwritten(bh) || buffer_delay(bh) || ((buffer_uptodate(bh) || PageUptodate(page)) && !buffer_mapped(bh) && (unmapped || startio))) { + /* + * Make sure we don't use a read-only iomap + */ + if (flags == BMAPI_READ) + iomap_valid = 0; + if (buffer_unwritten(bh)) { type = IOMAP_UNWRITTEN; flags = BMAPI_WRITE|BMAPI_IGNSTATE; @@ -887,14 +901,14 @@ xfs_page_state_convert( if (!startio) flags |= trylock_flag; } else { - type = 0; + type = IOMAP_NEW; flags = BMAPI_WRITE|BMAPI_MMAP; } if (!iomap_valid) { - if (type == 0) { - size = xfs_probe_unmapped_cluster(inode, - page, bh, head); + if (type == IOMAP_NEW) { + size = xfs_probe_cluster(inode, + page, bh, head, 0); } else { size = len; } @@ -921,10 +935,27 @@ xfs_page_state_convert( count++; } } else if (buffer_uptodate(bh) && startio) { - type = 0; + /* + * we got here because the buffer is already mapped. + * That means it must already have extents allocated + * underneath it. Map the extent by reading it. + */ + if (!iomap_valid || type != 0) { + flags = BMAPI_READ; + size = xfs_probe_cluster(inode, page, bh, + head, 1); + err = xfs_map_blocks(inode, offset, size, + &iomap, flags); + if (err) + goto error; + iomap_valid = xfs_iomap_valid(&iomap, offset); + } + type = 0; if (!test_and_set_bit(BH_Lock, &bh->b_state)) { ASSERT(buffer_mapped(bh)); + if (iomap_valid) + all_bh = 1; xfs_add_to_ioend(inode, bh, offset, type, &ioend, !iomap_valid); page_dirty--; @@ -953,7 +984,7 @@ xfs_page_state_convert( PAGE_CACHE_SHIFT; tlast = min_t(pgoff_t, offset, last_index); xfs_cluster_write(inode, page->index + 1, &iomap, &ioend, - wbc, startio, unmapped, tlast); + wbc, startio, all_bh, tlast); } if (iohead) -- cgit 1.2.3-korg