From 5d8edfb900d55db7dbf2dbf325bfb9fdb863ec72 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Sat, 20 May 2023 12:13:20 -0400 Subject: iomap: Copy larger chunks from userspace If we have a large folio, we can copy in larger chunks than PAGE_SIZE. Start at the maximum page cache size and shrink by half every time we hit the "we are short on memory" problem. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong --- fs/iomap/buffered-io.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-) (limited to 'fs/iomap') diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 00e0e94c953e..608cd2e5a7c9 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -769,6 +769,7 @@ static size_t iomap_write_end(struct iomap_iter *iter, loff_t pos, size_t len, static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) { loff_t length = iomap_length(iter); + size_t chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER; loff_t pos = iter->pos; ssize_t written = 0; long status = 0; @@ -777,15 +778,12 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) do { struct folio *folio; - struct page *page; - unsigned long offset; /* Offset into pagecache page */ - unsigned long bytes; /* Bytes to write to page */ + size_t offset; /* Offset into folio */ + size_t bytes; /* Bytes to write to folio */ size_t copied; /* Bytes copied from user */ - offset = offset_in_page(pos); - bytes = min_t(unsigned long, PAGE_SIZE - offset, - iov_iter_count(i)); -again: + offset = pos & (chunk - 1); + bytes = min(chunk - offset, iov_iter_count(i)); status = balance_dirty_pages_ratelimited_flags(mapping, bdp_flags); if (unlikely(status)) @@ -815,12 +813,14 @@ again: if (iter->iomap.flags & IOMAP_F_STALE) break; - page = folio_file_page(folio, pos >> PAGE_SHIFT); - if (mapping_writably_mapped(mapping)) - flush_dcache_page(page); + offset = offset_in_folio(folio, pos); + if (bytes > folio_size(folio) - offset) + bytes = folio_size(folio) - offset; - copied = copy_page_from_iter_atomic(page, offset, bytes, i); + if (mapping_writably_mapped(mapping)) + flush_dcache_folio(folio); + copied = copy_folio_from_iter_atomic(folio, offset, bytes, i); status = iomap_write_end(iter, pos, bytes, copied, folio); if (unlikely(copied != status)) @@ -836,11 +836,13 @@ again: */ if (copied) bytes = copied; - goto again; + if (chunk > PAGE_SIZE) + chunk /= 2; + } else { + pos += status; + written += status; + length -= status; } - pos += status; - written += status; - length -= status; } while (iov_iter_count(i) && length); if (status == -EAGAIN) { -- cgit