6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Christoph Hellwig hch@lst.de
[ Upstream commit 7a9d43eace888a0ee6095035997bb138425844d3 ]
When direct I/O completions invalidates the page cache it holds neither the i_rwsem nor the invalidate_lock so it can be racing with iomap_write_delalloc_release. If the search for the end of the region that contains data returns the start offset we hit such a race and just need to look for the end of the newly created hole instead.
Signed-off-by: Christoph Hellwig hch@lst.de Link: https://lore.kernel.org/r/20240910043949.3481298-2-hch@lst.de Reviewed-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/iomap/buffered-io.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 98617f00101d6..1833608f39318 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -990,7 +990,15 @@ static int iomap_write_delalloc_release(struct inode *inode, error = data_end; goto out_unlock; } - WARN_ON_ONCE(data_end <= start_byte); + + /* + * If we race with post-direct I/O invalidation of the page cache, + * there might be no data left at start_byte. + */ + if (data_end == start_byte) + continue; + + WARN_ON_ONCE(data_end < start_byte); WARN_ON_ONCE(data_end > scan_end_byte);
error = iomap_write_delalloc_scan(inode, &punch_start_byte,