From 7d6fe5c586e6a866f9e69a5bdd72a72b977bab8e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Oct 2024 10:59:20 +0200 Subject: [PATCH] xfs: set IOMAP_F_SHARED for all COW fork allocations Change to always set xfs_buffered_write_iomap_begin for COW fork allocations even if they don't overlap existing data fork extents, which will allow the iomap_end callback to detect if it has to punch stale delalloc blocks from the COW fork instead of the data fork. It also means we sample the sequence counter for both the data and the COW fork when writing to the COW fork, which ensures we properly revalidate when only COW fork changes happens. This is essentially a revert of commit 72a048c1056a ("xfs: only set IOMAP_F_SHARED when providing a srcmap to a write"). This is fine because the problem that the commit fixed has now been dealt with in iomap by only looking at the actual srcmap and not the fallback to the write iomap. Note that the direct I/O path was never changed and has always set IOMAP_F_SHARED for all COW fork allocations. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Carlos Maiolino --- fs/xfs/xfs_iomap.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index ebd0c90c1b3d..0317bbfeeb38 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -1186,20 +1186,20 @@ xfs_buffered_write_iomap_begin( return 0; found_cow: - seq = xfs_iomap_inode_sequence(ip, 0); if (imap.br_startoff <= offset_fsb) { - error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0, seq); + error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0, + xfs_iomap_inode_sequence(ip, 0)); if (error) goto out_unlock; - seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED); - xfs_iunlock(ip, lockmode); - return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, - IOMAP_F_SHARED, seq); + } else { + xfs_trim_extent(&cmap, offset_fsb, + imap.br_startoff - offset_fsb); } - xfs_trim_extent(&cmap, offset_fsb, imap.br_startoff - offset_fsb); + iomap_flags = IOMAP_F_SHARED; + seq = xfs_iomap_inode_sequence(ip, iomap_flags); xfs_iunlock(ip, lockmode); - return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, 0, seq); + return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, iomap_flags, seq); out_unlock: xfs_iunlock(ip, lockmode);