[PATCH] iomap: Remove FGP_NOFS from iomap_get_folio()

[PATCH] iomap: Remove FGP_NOFS from iomap_get_folio()

[Matthew Wilcox (Oracle)]

FGP_NOFS is legacy; filesystems should be using memalloc_nofs_save/restore
instead.  We have it here in iomap because it was buried in
grab_cache_page_write_begin() and we didn't want to change this behaviour
as part of the folio transition.

I have tested this with XFS and see no issues.  Other filesystems (cc'd)
may need to make adjustments.  Please test with lockdep enabled.

Cc: "Darrick J. Wong" <djwong@kernel.org> (iomap)
Cc: Jens Axboe <axboe@kernel.dk> (block)
Cc: Namjae Jeon <linkinjeon@kernel.org> (exfat, ntfs)
Cc: Sungjong Seo <sj1557.seo@samsung.com> (exfat)
Cc: Yuezhang Mo <yuezhang.mo@sony.com> (exfat)
Cc: Miklos Szeredi <miklos@szeredi.hu> (fuse)
Cc: Andreas Gruenbacher <agruenba@redhat.com> (gfs2)
Cc: Hyunchul Lee <hyc.lee@gmail.com> (ntfs)
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> (ntfs3)
Cc: Carlos Maiolino <cem@kernel.org> (xfs)
Cc: Damien Le Moal <dlemoal@kernel.org> (zonefs)
Cc: Naohiro Aota <naohiro.aota@wdc.com> (zonefs)
Cc: Johannes Thumshirn <jth@kernel.org> (zonefs)
Cc: linux-xfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-block@vger.kernel.org
Cc: fuse-devel@lists.linux.dev
Cc: gfs2@lists.linux.dev
Cc: ntfs3@lists.linux.dev
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/iomap/buffered-io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 8d4806dc46d4..27bc2455a98d 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -768,7 +768,7 @@ EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate);
  */
 struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos, size_t len)
 {
-	fgf_t fgp = FGP_WRITEBEGIN | FGP_NOFS;
+	fgf_t fgp = FGP_WRITEBEGIN;
 
 	if (iter->flags & IOMAP_NOWAIT)
 		fgp |= FGP_NOWAIT;
-- 
2.47.3

Re: [PATCH] iomap: Remove FGP_NOFS from iomap_get_folio()

[Christian Brauner]

On Wed, 24 Jun 2026 18:42:26 +0100, Matthew Wilcox (Oracle) wrote:
> iomap: Remove FGP_NOFS from iomap_get_folio()

Moving into -next so we see fallout...

---

Applied to the vfs-7.3.iomap branch of the vfs/vfs.git tree.
Patches in the vfs-7.3.iomap branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-7.3.iomap

[1/1] iomap: Remove FGP_NOFS from iomap_get_folio()
      https://git.kernel.org/vfs/vfs/c/ec17795fb797

Re: [PATCH] iomap: Remove FGP_NOFS from iomap_get_folio()

[Christoph Hellwig]

On Wed, Jun 24, 2026 at 06:42:26PM +0100, Matthew Wilcox (Oracle) wrote:
> FGP_NOFS is legacy; filesystems should be using memalloc_nofs_save/restore
> instead.  We have it here in iomap because it was buried in
> grab_cache_page_write_begin() and we didn't want to change this behaviour
> as part of the folio transition.
> 
> I have tested this with XFS and see no issues.  Other filesystems (cc'd)
> may need to make adjustments.  Please test with lockdep enabled.

I think the most interesting one to test here would be gfs2 as it has
rather alaborate locking in the write path.