Re: [PATCH 5/7] iomap: limit buffered I/O size to 128M
From: "Darrick J. Wong" <djwong@kernel.org>
Date: 2025-02-03 22:22:21
Also in:
linux-fsdevel, linux-xfs
On Mon, Feb 03, 2025 at 10:43:09AM +0100, Christoph Hellwig wrote:
quoted hunk ↗ jump to hunk
Currently iomap can build extremely large bios (I've seen sizes up to 480MB). Limit this to a lower bound so that the soon to be added per-ioend integrity buffer doesn't go beyond what the page allocator can support. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/iomap/buffered-io.c | 3 +++ 1 file changed, 3 insertions(+)diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 06990e012884..71bb676d4998 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c@@ -456,6 +456,7 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter, sector = iomap_sector(iomap, pos); if (!ctx->bio || bio_end_sector(ctx->bio) != sector || + ctx->bio->bi_iter.bi_size > SZ_128M ||
I imagine this is one of the XXX parts, but we probably shouldn't limit the bios for !pi filesystems that won't care. --D
quoted hunk ↗ jump to hunk
!bio_add_folio(ctx->bio, folio, plen, poff)) { if (ctx->bio) iomap_read_submit_bio(iter, ctx);@@ -1674,6 +1675,8 @@ static struct iomap_ioend *iomap_alloc_ioend(struct iomap_writepage_ctx *wpc, static bool iomap_can_add_to_ioend(struct iomap_writepage_ctx *wpc, loff_t pos, u16 ioend_flags) { + if (wpc->ioend->io_bio.bi_iter.bi_size > SZ_128M) + return false; if (ioend_flags & IOMAP_IOEND_BOUNDARY) return false; if ((ioend_flags & IOMAP_IOEND_NOMERGE_FLAGS) !=-- 2.45.2