virtiofs: add a mount option to enable dax (1dd53957) · Commits · 戴 / test

fs/fuse/Kconfig

+13 −0

Original line number	Diff line number	Diff line
		@@ -38,3 +38,16 @@ config VIRTIO_FS

		If you want to share files between guests or with the host, answer Y
		or M.

		config FUSE_DAX
		bool "Virtio Filesystem Direct Host Memory Access support"
		default y
		depends on VIRTIO_FS
		depends on FS_DAX
		depends on DAX_DRIVER
		help
		This allows bypassing guest page cache and allows mapping host page
		cache directly in guest address space.

		If you want to allow mounting a Virtio Filesystem with the "dax"
		option, answer Y.

+4 −2

Original line number	Diff line number	Diff line
		@@ -7,5 +7,7 @@ obj-$(CONFIG_FUSE_FS) += fuse.o
		obj-$(CONFIG_CUSE) += cuse.o
		obj-$(CONFIG_VIRTIO_FS) += virtiofs.o

		fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o
		virtiofs-y += virtio_fs.o
		fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o
		fuse-$(CONFIG_FUSE_DAX) += dax.o

		virtiofs-y := virtio_fs.o

0 → 100644

+36 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* dax: direct host memory access
		* Copyright (C) 2020 Red Hat, Inc.
		*/

		#include "fuse_i.h"

		#include <linux/dax.h>

		struct fuse_conn_dax {
		/* DAX device */
		struct dax_device *dev;
		};

		void fuse_dax_conn_free(struct fuse_conn *fc)
		{
		kfree(fc->dax);
		}

		int fuse_dax_conn_alloc(struct fuse_conn fc, struct dax_device dax_dev)
		{
		struct fuse_conn_dax *fcd;

		if (!dax_dev)
		return 0;

		fcd = kzalloc(sizeof(*fcd), GFP_KERNEL);
		if (!fcd)
		return -ENOMEM;

		fcd->dev = dax_dev;

		fc->dax = fcd;
		return 0;
		}

+14 −0

Original line number	Diff line number	Diff line
		@@ -483,10 +483,14 @@ struct fuse_fs_context {
		bool no_control:1;
		bool no_force_umount:1;
		bool legacy_opts_show:1;
		bool dax:1;
		unsigned int max_read;
		unsigned int blksize;
		const char *subtype;

		/* DAX device, may be NULL */
		struct dax_device *dax_dev;

		/* fuse_dev pointer to fill in, should contain NULL on entry */
		void **fudptr;
		};
		@@ -755,6 +759,11 @@ struct fuse_conn {

		/** List of device instances belonging to this connection */
		struct list_head devices;

		#ifdef CONFIG_FUSE_DAX
		/* Dax specific conn data, non-NULL if DAX is enabled */
		struct fuse_conn_dax *dax;
		#endif
		};

		static inline struct fuse_conn get_fuse_conn_super(struct super_block sb)
		@@ -1093,4 +1102,9 @@ unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
		u64 fuse_get_unique(struct fuse_iqueue *fiq);
		void fuse_free_conn(struct fuse_conn *fc);

		/* dax.c */

		int fuse_dax_conn_alloc(struct fuse_conn fc, struct dax_device dax_dev);
		void fuse_dax_conn_free(struct fuse_conn *fc);

		#endif /* _FS_FUSE_I_H */

+17 −1

Original line number	Diff line number	Diff line
		@@ -587,6 +587,11 @@ static int fuse_show_options(struct seq_file m, struct dentry root)
		if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
		seq_printf(m, ",blksize=%lu", sb->s_blocksize);
		}
		#ifdef CONFIG_FUSE_DAX
		if (fc->dax)
		seq_puts(m, ",dax");
		#endif

		return 0;
		}

		@@ -651,6 +656,8 @@ void fuse_conn_put(struct fuse_conn *fc)
		if (refcount_dec_and_test(&fc->count)) {
		struct fuse_iqueue *fiq = &fc->iq;

		if (IS_ENABLED(CONFIG_FUSE_DAX))
		fuse_dax_conn_free(fc);
		if (fiq->ops->release)
		fiq->ops->release(fiq);
		put_pid_ns(fc->pid_ns);
		@@ -1175,11 +1182,17 @@ int fuse_fill_super_common(struct super_block sb, struct fuse_fs_context ctx)
		if (sb->s_user_ns != &init_user_ns)
		sb->s_xattr = fuse_no_acl_xattr_handlers;

		if (IS_ENABLED(CONFIG_FUSE_DAX)) {
		err = fuse_dax_conn_alloc(fc, ctx->dax_dev);
		if (err)
		goto err;
		}

		if (ctx->fudptr) {
		err = -ENOMEM;
		fud = fuse_dev_alloc_install(fc);
		if (!fud)
		goto err;
		goto err_free_dax;
		}

		fc->dev = sb->s_dev;
		@@ -1234,6 +1247,9 @@ int fuse_fill_super_common(struct super_block sb, struct fuse_fs_context ctx)
		err_dev_free:
		if (fud)
		fuse_dev_free(fud);
		err_free_dax:
		if (IS_ENABLED(CONFIG_FUSE_DAX))
		fuse_dax_conn_free(fc);
		err:
		return err;
		}