From 77c475692c5e4e72eee9de869056008e62d3733b Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Fri, 3 Oct 2025 09:46:39 -0400 Subject: [PATCH] xfs: fill dirty folios on zero range of unwritten mappings Use the iomap folio batch mechanism to select folios to zero on zero range of unwritten mappings. Trim the resulting mapping if the batch is filled (unlikely for current use cases) to distinguish between a range to skip and one that requires another iteration due to a full batch. Signed-off-by: Brian Foster Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner --- fs/xfs/xfs_iomap.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 6a05e04ad5ba4..535bf3b8705db 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -1702,6 +1702,8 @@ xfs_buffered_write_iomap_begin( struct iomap *iomap, struct iomap *srcmap) { + struct iomap_iter *iter = container_of(iomap, struct iomap_iter, + iomap); struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); @@ -1773,6 +1775,7 @@ xfs_buffered_write_iomap_begin( */ if (flags & IOMAP_ZERO) { xfs_fileoff_t eof_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)); + u64 end; if (isnullstartblock(imap.br_startblock) && offset_fsb >= eof_fsb) @@ -1780,6 +1783,26 @@ xfs_buffered_write_iomap_begin( if (offset_fsb < eof_fsb && end_fsb > eof_fsb) end_fsb = eof_fsb; + /* + * Look up dirty folios for unwritten mappings within EOF. + * Providing this bypasses the flush iomap uses to trigger + * extent conversion when unwritten mappings have dirty + * pagecache in need of zeroing. + * + * Trim the mapping to the end pos of the lookup, which in turn + * was trimmed to the end of the batch if it became full before + * the end of the mapping. + */ + if (imap.br_state == XFS_EXT_UNWRITTEN && + offset_fsb < eof_fsb) { + loff_t len = min(count, + XFS_FSB_TO_B(mp, imap.br_blockcount)); + + end = iomap_fill_dirty_folios(iter, offset, len); + end_fsb = min_t(xfs_fileoff_t, end_fsb, + XFS_B_TO_FSB(mp, end)); + } + xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb); } -- 2.47.3