[PATCH V7 17/19] famfs_fuse: Add DAX address_space_operations with noop_dirty_folio
From: John Groves <hidden>
Date: 2026-01-18 22:33:53
Also in:
linux-cxl, linux-fsdevel, lkml, nvdimm
Subsystem:
filesystems (vfs and infrastructure), fuse filesystem [core], the rest · Maintainers:
Alexander Viro, Christian Brauner, Miklos Szeredi, Linus Torvalds
From: John Groves <John@Groves.net> Famfs is memory-backed; there is no place to write back to, and no reason to mark pages dirty at all. Signed-off-by: John Groves <john@groves.net> --- fs/fuse/famfs.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/fs/fuse/famfs.c b/fs/fuse/famfs.c
index b38e92d8f381..90325bd14354 100644
--- a/fs/fuse/famfs.c
+++ b/fs/fuse/famfs.c@@ -14,6 +14,7 @@ #include <linux/mm.h> #include <linux/dax.h> #include <linux/iomap.h> +#include <linux/pagemap.h> #include <linux/path.h> #include <linux/namei.h> #include <linux/string.h>
@@ -39,6 +40,15 @@ static const struct dax_holder_operations famfs_fuse_dax_holder_ops = { .notify_failure = famfs_dax_notify_failure, }; +/* + * DAX address_space_operations for famfs. + * famfs doesn't need dirty tracking - writes go directly to + * memory with no writeback required. + */ +static const struct address_space_operations famfs_dax_aops = { + .dirty_folio = noop_dirty_folio, +}; + /*****************************************************************************/ /*
@@ -627,6 +637,7 @@ famfs_file_init_dax( if (famfs_meta_set(fi, meta) == NULL) { i_size_write(inode, meta->file_size); inode->i_flags |= S_DAX; + inode->i_data.a_ops = &famfs_dax_aops; } else { pr_debug("%s: file already had metadata\n", __func__); __famfs_meta_free(meta);
--
2.52.0