On Thu, Jul 03, 2025 at 01:50:25PM -0500, John Groves wrote: > * -o shadow=<shadowpath>
What is a shadow? > * -o daxdev=<daxdev> And, uh, if there's a FUSE_GET_DAXDEV command, then what does this mount option do? Pre-populate the first element of that set? --D > Signed-off-by: John Groves <[email protected]> > --- > fs/fuse/fuse_i.h | 8 +++++++- > fs/fuse/inode.c | 28 +++++++++++++++++++++++++++- > 2 files changed, 34 insertions(+), 2 deletions(-) > > diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h > index a592c1002861..f4ee61046578 100644 > --- a/fs/fuse/fuse_i.h > +++ b/fs/fuse/fuse_i.h > @@ -583,9 +583,11 @@ struct fuse_fs_context { > unsigned int blksize; > const char *subtype; > > - /* DAX device, may be NULL */ > + /* DAX device for virtiofs, may be NULL */ > struct dax_device *dax_dev; > > + const char *shadow; /* famfs - null if not famfs */ > + > /* fuse_dev pointer to fill in, should contain NULL on entry */ > void **fudptr; > }; > @@ -941,6 +943,10 @@ struct fuse_conn { > /** uring connection information*/ > struct fuse_ring *ring; > #endif > + > +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) > + char *shadow; > +#endif > }; > > /* > diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c > index e48e11c3f9f3..a7e1cf8257b0 100644 > --- a/fs/fuse/inode.c > +++ b/fs/fuse/inode.c > @@ -766,6 +766,9 @@ enum { > OPT_ALLOW_OTHER, > OPT_MAX_READ, > OPT_BLKSIZE, > +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) > + OPT_SHADOW, > +#endif > OPT_ERR > }; > > @@ -780,6 +783,9 @@ static const struct fs_parameter_spec > fuse_fs_parameters[] = { > fsparam_u32 ("max_read", OPT_MAX_READ), > fsparam_u32 ("blksize", OPT_BLKSIZE), > fsparam_string ("subtype", OPT_SUBTYPE), > +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) > + fsparam_string("shadow", OPT_SHADOW), > +#endif > {} > }; > > @@ -875,6 +881,15 @@ static int fuse_parse_param(struct fs_context *fsc, > struct fs_parameter *param) > ctx->blksize = result.uint_32; > break; > > +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) > + case OPT_SHADOW: > + if (ctx->shadow) > + return invalfc(fsc, "Multiple shadows specified"); > + ctx->shadow = param->string; > + param->string = NULL; > + break; > +#endif > + > default: > return -EINVAL; > } > @@ -888,6 +903,7 @@ static void fuse_free_fsc(struct fs_context *fsc) > > if (ctx) { > kfree(ctx->subtype); > + kfree(ctx->shadow); > kfree(ctx); > } > } > @@ -919,7 +935,10 @@ static int fuse_show_options(struct seq_file *m, struct > dentry *root) > else if (fc->dax_mode == FUSE_DAX_INODE_USER) > seq_puts(m, ",dax=inode"); > #endif > - > +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) > + if (fc->shadow) > + seq_printf(m, ",shadow=%s", fc->shadow); > +#endif > return 0; > } > > @@ -1017,6 +1036,9 @@ void fuse_conn_put(struct fuse_conn *fc) > } > if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) > fuse_backing_files_free(fc); > +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) > + kfree(fc->shadow); > +#endif > call_rcu(&fc->rcu, delayed_release); > } > } > @@ -1834,6 +1856,10 @@ int fuse_fill_super_common(struct super_block *sb, > struct fuse_fs_context *ctx) > sb->s_root = root_dentry; > if (ctx->fudptr) > *ctx->fudptr = fud; > + > +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) > + fc->shadow = kstrdup(ctx->shadow, GFP_KERNEL); > +#endif > mutex_unlock(&fuse_mutex); > return 0; > > -- > 2.49.0 > >
