From nobody Mon Feb 9 23:04:26 2026 Received: from mail-ot1-f46.google.com (mail-ot1-f46.google.com [209.85.210.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A88531C84BC; Mon, 21 Apr 2025 01:34:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.46 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745199273; cv=none; b=dtRHivjcTUaYvUW5nfACjFP+gOALM+UiVIPIpYcNVvpjerLGwqAuqaESLMM2N8kWqp8kvXizqzD4UDZ0U0UFQij0UpDPG8TiN1jJCeUEe0pDl5uCdjhAn+Vs/SUs8bTwKi9mt8O+8LgSUReUEgURveHQFX3PLkes/2fyLoAM8G4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745199273; c=relaxed/simple; bh=Jht53ChYFHgs9fVdkHxX2GDuBPGNdx3JRH/1uFqn5+Q=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TqGiCP4T9dhjPfdN4ebMzYE5hcg4oJnxiacBu0rDcfJ25bioXxnkpW+axNTzNzqrI/s4Td4mysdgn9EWhavVfx9Ajee6NpGcd7UOiG0rlGbipnmgq/Eye/xyeu4rEC5PbZcSBN5DQTfJZ9Va23mxldt3ketuUtr+5ngpnyqron8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=Groves.net; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=d6Wja49Y; arc=none smtp.client-ip=209.85.210.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=Groves.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="d6Wja49Y" Received: by mail-ot1-f46.google.com with SMTP id 46e09a7af769-7272f9b4132so3007827a34.0; Sun, 20 Apr 2025 18:34:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1745199271; x=1745804071; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=87hDz9VklLiiv0z6ZzoGmsWmujXBj1aSDF9l5QzufPk=; b=d6Wja49YOmNmk8sk/Al3t0bx0wf57fjCupxD1mZ+t+HzjvFmHHaqF+5q10STxbnx0I yh8tvzim94bvx+AQQ/pbd++kWEjYMFrLuzlzyF6u4aulLd4Ar3p47CBbRX1OGdKfBtpo AQOCnQLYThO49oY8nNItmU4nX9LOIaRBZQmGQs15ADHhNH+ohnaNmJs/baVlx+Xeay8s XLhewDpkWmgmr5uO16E+pgBbhHuKsZyITXYRzk/Slepee97/OFebiI6XswBpKS7Gf4I1 645eFdx4LawDYOGHxHz+ssogAInQMpDksjY0v+ADNyC/XyaXFhDweO1AR3bWEJjK3VjT XLpQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745199271; x=1745804071; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=87hDz9VklLiiv0z6ZzoGmsWmujXBj1aSDF9l5QzufPk=; b=bgAbLrJXz4ecJCRUeslAfjjNsRRgj9pDTTCluWta5tirKvH2csnxWGpGE0y010DoWr RUonC1pqF4Bhofgp3TgL3U5ClKkAbiuKMAikWUEZl0M8+luvFaC0cvPzUSx9Q/C/FuP6 VjRnwwiehU0hxiTrl6KeKW8JTvodt+4vDxh17TpbvUoywaEMl/NUfmWU2/VdX6RFKJUc HoCweSJ8C9ZZv+qatxBnXJUhErj+8kqz0qOPapIZzSNNQbI7X9KRz0wHatEwGmXsnPwW BVHZBNzbqyvfeKJOtyA9QN/nI7HeAlK3zWtx9qZdv3q2ihvpJFq+Bv7eIVEjI00eBfcp BoeQ== X-Forwarded-Encrypted: i=1; AJvYcCUdLo2UPSRm2l82dFAKU1PK/Tyd072TJTvZkh/H6l+yQL5u1OymUxW83V3/PN8blhSa/rsawc2VYfnTFN31Mg==@vger.kernel.org, AJvYcCUqUR/IR2GY+5HcB0JKuP6nrsrMEmu6Ac5OgK3QcbVSEm/K/QMY89jwPdgNmH4xVcaYdnDlHiKTIpU=@vger.kernel.org, AJvYcCVcwpXigDVdMtwh2UIzdw0RWqQM+84P//IM/5kuFmgpq9P8bFUB16rY0I05BDBf5qZlRDEJ/FF44CFQ@vger.kernel.org, AJvYcCXJSKWwm0Sigmr//l+fiwq3Hd/mOHsaRTZejHcaKCpBL9IR018cf9dWsjm+Jc9tESTp2zk6IZQMD1q3dhCn@vger.kernel.org X-Gm-Message-State: AOJu0YzWOc00EWJZPVIv6SgHJ27yiPXVfrcwMR5pXVmbZes3YE2zssjn KKvPekcC3r4hZPTT6JxOFA6MmiONubitrA9W7tGIHe1NdqQ16ewY X-Gm-Gg: ASbGncvIun3afxJXvb4Cdr7ix5arS/C5r1JqUjm5DMCYq/nBnttUo/knMWdjATAvsRw GOBvsbyAb2YenIyona+5pXj9jXPgn1IobX1YBbsDMtSxju3qD0kWzCFEOnGYzWaftdZTGjxCret TW9eIDAmfw+c2bH2PLhQdM0rIoc7imzt1FB3bsBiwfNVnByONus6uGfarnPCokQUPQYaanBedUp I+U+oehTOGpT40ibZN+ZidoWDxGWvPXl5T9ncK78+XXxANqcx8yK+rkPQtw8e7q2tA3eHP2JpbU HxX6l9PijdhwNCGXTBIFf5JTYMWDgUAvkpu5XK/+6ebbHMeOUxtCcmigFAEP+2CTnb2E3w== X-Google-Smtp-Source: AGHT+IGp4vZtteKLozsEBPtZC1nWHMzjwcz0JoCBKnIYiH3inoL0umeX/iB+Kt+6JBcOpEy/kE2pLg== X-Received: by 2002:a05:6830:6203:b0:72a:47ec:12da with SMTP id 46e09a7af769-7300621892cmr6947779a34.10.1745199270715; Sun, 20 Apr 2025 18:34:30 -0700 (PDT) Received: from localhost.localdomain ([2603:8080:1500:3d89:a8f7:1b36:93ce:8dbf]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-7300489cd44sm1267588a34.66.2025.04.20.18.34.28 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Sun, 20 Apr 2025 18:34:30 -0700 (PDT) Sender: John Groves From: John Groves X-Google-Original-From: John Groves To: John Groves , Dan Williams , Miklos Szeredi , Bernd Schubert Cc: John Groves , Jonathan Corbet , Vishal Verma , Dave Jiang , Matthew Wilcox , Jan Kara , Alexander Viro , Christian Brauner , "Darrick J . Wong" , Luis Henriques , Randy Dunlap , Jeff Layton , Kent Overstreet , Petr Vorel , Brian Foster , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org, Amir Goldstein , Jonathan Cameron , Stefan Hajnoczi , Joanne Koong , Josef Bacik , Aravind Ramesh , Ajay Joshi , John Groves Subject: [RFC PATCH 12/19] famfs_fuse: Plumb the GET_FMAP message/response Date: Sun, 20 Apr 2025 20:33:39 -0500 Message-Id: <20250421013346.32530-13-john@groves.net> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20250421013346.32530-1-john@groves.net> References: <20250421013346.32530-1-john@groves.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Upon completion of a LOOKUP, if we're in famfs-mode we do a GET_FMAP to retrieve and cache up the file-to-dax map in the kernel. If this succeeds, read/write/mmap are resolved direct-to-dax with no upcalls. Signed-off-by: John Groves --- fs/fuse/dir.c | 69 +++++++++++++++++++++++++++++++++++++++ fs/fuse/fuse_i.h | 36 +++++++++++++++++++- fs/fuse/inode.c | 15 +++++++++ include/uapi/linux/fuse.h | 4 +++ 4 files changed, 123 insertions(+), 1 deletion(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index bc29db0117f4..ae135c55b9f6 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -359,6 +359,56 @@ bool fuse_invalid_attr(struct fuse_attr *attr) return !fuse_valid_type(attr->mode) || !fuse_valid_size(attr->size); } =20 +#define FMAP_BUFSIZE 4096 + +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) +static void +fuse_get_fmap_init( + struct fuse_conn *fc, + struct fuse_args *args, + u64 nodeid, + void *outbuf, + size_t outbuf_size) +{ + memset(outbuf, 0, outbuf_size); + args->opcode =3D FUSE_GET_FMAP; + args->nodeid =3D nodeid; + + args->in_numargs =3D 0; + + args->out_numargs =3D 1; + args->out_args[0].size =3D FMAP_BUFSIZE; + args->out_args[0].value =3D outbuf; +} + +static int +fuse_get_fmap(struct fuse_mount *fm, struct inode *inode, u64 nodeid) +{ + size_t fmap_size; + void *fmap_buf; + int err; + + pr_notice("%s: nodeid=3D%lld, inode=3D%llx\n", __func__, + nodeid, (u64)inode); + fmap_buf =3D kcalloc(1, FMAP_BUFSIZE, GFP_KERNEL); + FUSE_ARGS(args); + fuse_get_fmap_init(fm->fc, &args, nodeid, fmap_buf, FMAP_BUFSIZE); + + /* Send GET_FMAP command */ + err =3D fuse_simple_request(fm, &args); + if (err) { + pr_err("%s: err=3D%d from fuse_simple_request()\n", + __func__, err); + return err; + } + + fmap_size =3D args.out_args[0].size; + pr_notice("%s: nodei=3D%lld fmap_size=3D%ld\n", __func__, nodeid, fmap_si= ze); + + return 0; +} +#endif + int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr= *name, struct fuse_entry_out *outarg, struct inode **inode) { @@ -404,6 +454,25 @@ int fuse_lookup_name(struct super_block *sb, u64 nodei= d, const struct qstr *name fuse_queue_forget(fm->fc, forget, outarg->nodeid, 1); goto out; } + +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) + if (fm->fc->famfs_iomap) { + if (S_ISREG((*inode)->i_mode)) { + /* Note Lookup returns the looked-up inode in the attr + * struct, but not in outarg->nodeid ! + */ + pr_notice("%s: outarg: size=3D%d nodeid=3D%lld attr.ino=3D%lld\n", + __func__, args.out_args[0].size, outarg->nodeid, + outarg->attr.ino); + /* Get the famfs fmap */ + fuse_get_fmap(fm, *inode, outarg->attr.ino); + } else + pr_notice("%s: no get_fmap for non-regular file\n", + __func__); + } else + pr_notice("%s: fc->dax_iomap is not set\n", __func__); +#endif + err =3D 0; =20 out_put_forget: diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 931613102d32..437177c2f092 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -193,6 +193,10 @@ struct fuse_inode { /** Reference to backing file in passthrough mode */ struct fuse_backing *fb; #endif + +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) + void *famfs_meta; +#endif }; =20 /** FUSE inode state bits */ @@ -942,6 +946,8 @@ struct fuse_conn { #endif =20 #if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) + struct rw_semaphore famfs_devlist_sem; + struct famfs_dax_devlist *dax_devlist; char *shadow; #endif }; @@ -1432,11 +1438,14 @@ void fuse_free_conn(struct fuse_conn *fc); =20 /* dax.c */ =20 +static inline int fuse_file_famfs(struct fuse_inode *fi); /* forward */ + /* This macro is used by virtio_fs, but now it also needs to filter for * "not famfs" */ #define FUSE_IS_VIRTIO_DAX(fuse_inode) (IS_ENABLED(CONFIG_FUSE_DAX) \ - && IS_DAX(&fuse_inode->inode)) + && IS_DAX(&fuse_inode->inode) \ + && !fuse_file_famfs(fuse_inode)) =20 ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to); ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from); @@ -1547,4 +1556,29 @@ extern void fuse_sysctl_unregister(void); #define fuse_sysctl_unregister() do { } while (0) #endif /* CONFIG_SYSCTL */ =20 +/* famfs.c */ +static inline struct fuse_backing *famfs_meta_set(struct fuse_inode *fi, + void *meta) +{ +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) + return xchg(&fi->famfs_meta, meta); +#else + return NULL; +#endif +} + +static inline void famfs_meta_free(struct fuse_inode *fi) +{ + /* Stub wil be connected in a subsequent commit */ +} + +static inline int fuse_file_famfs(struct fuse_inode *fi) +{ +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) + return (fi->famfs_meta !=3D NULL); +#else + return 0; +#endif +} + #endif /* _FS_FUSE_I_H */ diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 7f4b73e739cb..848c8818e6f7 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -117,6 +117,9 @@ static struct inode *fuse_alloc_inode(struct super_bloc= k *sb) if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) fuse_inode_backing_set(fi, NULL); =20 + if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX)) + famfs_meta_set(fi, NULL); + return &fi->inode; =20 out_free_forget: @@ -138,6 +141,13 @@ static void fuse_free_inode(struct inode *inode) if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) fuse_backing_put(fuse_inode_backing(fi)); =20 +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) + if (S_ISREG(inode->i_mode) && fi->famfs_meta) { + famfs_meta_free(fi); + famfs_meta_set(fi, NULL); + } +#endif + kmem_cache_free(fuse_inode_cachep, fi); } =20 @@ -1002,6 +1012,11 @@ void fuse_conn_init(struct fuse_conn *fc, struct fus= e_mount *fm, if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) fuse_backing_files_init(fc); =20 + if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX)) { + pr_notice("%s: Kernel is FUSE_FAMFS_DAX capable\n", __func__); + init_rwsem(&fc->famfs_devlist_sem); + } + INIT_LIST_HEAD(&fc->mounts); list_add(&fm->fc_entry, &fc->mounts); fm->fc =3D fc; diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index f9e14180367a..d85fb692cf3b 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -652,6 +652,10 @@ enum fuse_opcode { FUSE_TMPFILE =3D 51, FUSE_STATX =3D 52, =20 + /* Famfs / devdax opcodes */ + FUSE_GET_FMAP =3D 53, + FUSE_GET_DAXDEV =3D 54, + /* CUSE specific operations */ CUSE_INIT =3D 4096, =20 --=20 2.49.0