[PATCH v3 27/59] netfs: Allocate multipage folios in the writepath

David Howells
2023-12-07T21:24:09Z

Allocate a multipage folio when copying data into the pagecache if possible
if there's sufficient data to warrant it.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
---
fs/netfs/buffered_write.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 6e7f06d9962d..b76688e98f81 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -84,14 +84,19 @@ static enum netfs_how_to_modify netfs_how_to_modify(struct netfs_inode *ctx,
}

/*
- * Grab a folio for writing and lock it.
+ * Grab a folio for writing and lock it. Attempt to allocate as large a folio
+ * as possible to hold as much of the remaining length as possible in one go.
*/
static struct folio *netfs_grab_folio_for_write(struct address_space *mapping,
loff_t pos, size_t part)
{
pgoff_t index = pos / PAGE_SIZE;
+ fgf_t fgp_flags = FGP_WRITEBEGIN;

- return __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
+ if (mapping_large_folio_support(mapping))
+ fgp_flags |= fgf_set_order(pos % PAGE_SIZE + part);
+
+ return __filemap_get_folio(mapping, index, fgp_flags,
mapping_gfp_mask(mapping));
}