shmem: provide a shmem_write_folio wrapper

Patch series "better block swap batching and a different take on swap_ops
v5".

This series makes use of the swap_iocb for block as well so that it
doesn't do inefficient single-bio I/O, and then rebases the swap_ops from
Baoquan on top of the now very different method structure.

When running doing kernels builds, which is a workload that doesn't really
do much THP anonymous memory it still gets 2x clustering for writeout and
1.2x for reading back swap in.  The overall times do not actually change,
though.


This patch (of 7):

Provide a wrapper for the shmem abuses in drm to prepare for swap I/O
refactoring by keeping swap_iocb handling entirely contained in mm/.

Link: https://lore.kernel.org/20260713093350.2154226-1-hch@lst.de
Link: https://lore.kernel.org/20260713093350.2154226-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Baoquan He <baoquan.he@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Chris Li <chrisl@kernel.org>
Reviewed-by: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Youngjun Park <youngjun.park@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 1 insertions, 4 deletions

diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index e729b9b0e38d..5663dff53186 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -12,8 +12,6 @@
 #include <linux/userfaultfd_k.h>
 #include <linux/bits.h>
 
-struct swap_iocb;
-
 /* inode in-kernel data */
 
 #ifdef CONFIG_TMPFS_QUOTA
@@ -123,8 +121,7 @@ static inline bool shmem_mapping(const struct address_space *mapping)
 void shmem_unlock_mapping(struct address_space *mapping);
 struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
 					pgoff_t index, gfp_t gfp_mask);
-int shmem_writeout(struct folio *folio, struct swap_iocb **plug,
-		struct list_head *folio_list);
+int shmem_write_folio(struct folio *folio);
 void shmem_truncate_range(struct inode *inode, loff_t start, uoff_t end);
 int shmem_unuse(unsigned int type);