[Virtio-fs] [PATCH v4 5/8] fuse: enable per-file DAX

[Jeffle Xu]

Enable per-file DAX if fuse server advertises that the file supports
that.

Currently the state whether the file enables DAX or not is initialized
only when inode is instantiated.

Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
---
 fs/fuse/dax.c    | 12 ++++++++----
 fs/fuse/file.c   |  4 ++--
 fs/fuse/fuse_i.h |  4 ++--
 fs/fuse/inode.c  |  2 +-
 4 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index fe4e9593a590..30833f8d37dd 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -1339,7 +1339,7 @@ static const struct address_space_operations fuse_dax_file_aops  = {
 	.invalidatepage	= noop_invalidatepage,
 };
 
-static bool fuse_should_enable_dax(struct inode *inode)
+static bool fuse_should_enable_dax(struct inode *inode, unsigned int flags)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	unsigned int dax_mode = fc->dax_mode;
@@ -1348,12 +1348,16 @@ static bool fuse_should_enable_dax(struct inode *inode)
 	if (dax_mode == FUSE_DAX_NEVER)
 		return false;
 
-	return true;
+	if (dax_mode == FUSE_DAX_ALWAYS)
+		return true;
+
+	WARN_ON_ONCE(dax_mode != FUSE_DAX_INODE);
+	return fc->perfile_dax && (flags & FUSE_ATTR_DAX);
 }
 
-void fuse_dax_inode_init(struct inode *inode)
+void fuse_dax_inode_init(struct inode *inode, unsigned int flags)
 {
-	if (!fuse_should_enable_dax(inode))
+	if (!fuse_should_enable_dax(inode, flags))
 		return;
 
 	inode->i_flags |= S_DAX;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index ec48bc7ef0a5..1231128f8dd6 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3148,7 +3148,7 @@ static const struct address_space_operations fuse_file_aops  = {
 	.write_end	= fuse_write_end,
 };
 
-void fuse_init_file_inode(struct inode *inode)
+void fuse_init_file_inode(struct inode *inode, unsigned int flags)
 {
 	struct fuse_inode *fi = get_fuse_inode(inode);
 
@@ -3162,5 +3162,5 @@ void fuse_init_file_inode(struct inode *inode)
 	fi->writepages = RB_ROOT;
 
 	if (IS_ENABLED(CONFIG_FUSE_DAX))
-		fuse_dax_inode_init(inode);
+		fuse_dax_inode_init(inode, flags);
 }
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 0b21e76a379a..7b7b4c208af2 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1006,7 +1006,7 @@ int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 /**
  * Initialize file operations on a regular file
  */
-void fuse_init_file_inode(struct inode *inode);
+void fuse_init_file_inode(struct inode *inode, unsigned int flags);
 
 /**
  * Initialize inode operations on regular files and special files
@@ -1258,7 +1258,7 @@ int fuse_dax_conn_alloc(struct fuse_conn *fc, enum fuse_dax_mode mode,
 			struct dax_device *dax_dev);
 void fuse_dax_conn_free(struct fuse_conn *fc);
 bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
-void fuse_dax_inode_init(struct inode *inode);
+void fuse_dax_inode_init(struct inode *inode, unsigned int flags);
 void fuse_dax_inode_cleanup(struct inode *inode);
 bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
 void fuse_dax_cancel_work(struct fuse_conn *fc);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 9d302079281c..8080f78befed 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -281,7 +281,7 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 	inode->i_ctime.tv_nsec = attr->ctimensec;
 	if (S_ISREG(inode->i_mode)) {
 		fuse_init_common(inode);
-		fuse_init_file_inode(inode);
+		fuse_init_file_inode(inode, attr->flags);
 	} else if (S_ISDIR(inode->i_mode))
 		fuse_init_dir(inode);
 	else if (S_ISLNK(inode->i_mode))
-- 
2.27.0