diff options
| -rw-r--r-- | fs/fuse/Kconfig | 13 | ||||
| -rw-r--r-- | fs/fuse/Makefile | 6 | ||||
| -rw-r--r-- | fs/fuse/dax.c | 36 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 14 | ||||
| -rw-r--r-- | fs/fuse/inode.c | 18 | ||||
| -rw-r--r-- | fs/fuse/virtio_fs.c | 81 |
6 files changed, 151 insertions, 17 deletions
diff --git a/fs/fuse/Kconfig b/fs/fuse/Kconfig index 0156dc8aa646..fddd40630077 100644 --- a/fs/fuse/Kconfig +++ b/fs/fuse/Kconfig @@ -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. diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile index 3e8cebfb59b7..8c7021fb2cd4 100644 --- a/fs/fuse/Makefile +++ b/fs/fuse/Makefile @@ -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 diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c new file mode 100644 index 000000000000..9660d01f49a5 --- /dev/null +++ b/fs/fuse/dax.c @@ -0,0 +1,36 @@ +// 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; +} diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 30737aabd932..97af7952373a 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -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 */ diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index bdae765b2d42..1780dfe063ab 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -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; } diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index f31a59f74475..e25f62276050 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -13,6 +13,7 @@ #include <linux/virtio_fs.h> #include <linux/delay.h> #include <linux/fs_context.h> +#include <linux/fs_parser.h> #include <linux/highmem.h> #include <linux/uio.h> #include "fuse_i.h" @@ -81,6 +82,44 @@ struct virtio_fs_req_work { static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq, struct fuse_req *req, bool in_flight); +enum { + OPT_DAX, +}; + +static const struct fs_parameter_spec virtio_fs_parameters[] = { + fsparam_flag("dax", OPT_DAX), + {} +}; + +static int virtio_fs_parse_param(struct fs_context *fc, + struct fs_parameter *param) +{ + struct fs_parse_result result; + struct fuse_fs_context *ctx = fc->fs_private; + int opt; + + opt = fs_parse(fc, virtio_fs_parameters, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case OPT_DAX: + ctx->dax = 1; + break; + default: + return -EINVAL; + } + + return 0; +} + +static void virtio_fs_free_fc(struct fs_context *fc) +{ + struct fuse_fs_context *ctx = fc->fs_private; + + kfree(ctx); +} + static inline struct virtio_fs_vq *vq_to_fsvq(struct virtqueue *vq) { struct virtio_fs *fs = vq->vdev->priv; @@ -1219,23 +1258,27 @@ static const struct fuse_iqueue_ops virtio_fs_fiq_ops = { .release = virtio_fs_fiq_release, }; -static int virtio_fs_fill_super(struct super_block *sb) +static inline void virtio_fs_ctx_set_defaults(struct fuse_fs_context *ctx) +{ + ctx->rootmode = S_IFDIR; + ctx->default_permissions = 1; + ctx->allow_other = 1; + ctx->max_read = UINT_MAX; + ctx->blksize = 512; + ctx->destroy = true; + ctx->no_control = true; + ctx->no_force_umount = true; +} + +static int virtio_fs_fill_super(struct super_block *sb, struct fs_context *fsc) { struct fuse_conn *fc = get_fuse_conn_super(sb); struct virtio_fs *fs = fc->iq.priv; + struct fuse_fs_context *ctx = fsc->fs_private; unsigned int i; int err; - struct fuse_fs_context ctx = { - .rootmode = S_IFDIR, - .default_permissions = 1, - .allow_other = 1, - .max_read = UINT_MAX, - .blksize = 512, - .destroy = true, - .no_control = true, - .no_force_umount = true, - }; + virtio_fs_ctx_set_defaults(ctx); mutex_lock(&virtio_fs_mutex); /* After holding mutex, make sure virtiofs device is still there. @@ -1259,8 +1302,10 @@ static int virtio_fs_fill_super(struct super_block *sb) } /* virtiofs allocates and installs its own fuse devices */ - ctx.fudptr = NULL; - err = fuse_fill_super_common(sb, &ctx); + ctx->fudptr = NULL; + if (ctx->dax) + ctx->dax_dev = fs->dax_dev; + err = fuse_fill_super_common(sb, ctx); if (err < 0) goto err_free_fuse_devs; @@ -1371,7 +1416,7 @@ static int virtio_fs_get_tree(struct fs_context *fsc) return PTR_ERR(sb); if (!sb->s_root) { - err = virtio_fs_fill_super(sb); + err = virtio_fs_fill_super(sb, fsc); if (err) { deactivate_locked_super(sb); return err; @@ -1386,11 +1431,19 @@ static int virtio_fs_get_tree(struct fs_context *fsc) } static const struct fs_context_operations virtio_fs_context_ops = { + .free = virtio_fs_free_fc, + .parse_param = virtio_fs_parse_param, .get_tree = virtio_fs_get_tree, }; static int virtio_fs_init_fs_context(struct fs_context *fsc) { + struct fuse_fs_context *ctx; + + ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + fsc->fs_private = ctx; fsc->ops = &virtio_fs_context_ops; return 0; } |