From nobody Thu Aug 28 15:28:28 2025 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4cCQK84k7Jz66BMx; Thu, 28 Aug 2025 15:28:28 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4cCQK846lsz49Cg; Thu, 28 Aug 2025 15:28:28 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1756394908; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=Esg1a9oOnrfXvj6JOpUFe7MudLrD8DhDu5GVF9ueq50=; b=DBWlRrGF73bz9LdwEgOOeqa0Hf/Rk2zjJnjF6NJBZR+FJ9B9THtCjp7JTTPufLFTNfm0Qy 3zMcSrUdHDbaqHKbjMg8Brk+8csdaZUrTPDUoBMjAJDf7qfJnaHLginI/elpO2jG9K5jem D6w0wi0VDZR1kTctJQ3C7oRaMlJy0CRVPJPpSLInYSs1U6ppUWm/dKeP8BErmbmtoXqTWW cg0Dvt+lvZDWqqVzMGcZLybHjNg9HpMTiDc0YZwpTxpWRrUge5VVlnCWN93AQ+rfb1rJbL FsJ7lZdwACNnQYI58dPs7OHqVegKl4RNLciIpRyb9uhAYU4WPS8z2SZ18e0lzw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1756394908; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=Esg1a9oOnrfXvj6JOpUFe7MudLrD8DhDu5GVF9ueq50=; b=cpsCSMjiscg4g4CxgFiah0RgMNRWyAVgUEdJIGNIeKrKozYQbSZKibh+dU0RlNKn3x62/w lL4i0zI7ZudL2yusqwQu+sq6fn43LfXsLc4mM9nEDfvayXt1ifqt97dHKlQKit+gi/0izM xvetfkZ+Y+gqLzVSTgjV3oF/e2QMexED3GNyuxEmlqIJ/7vcTh95lO9UkrB2d2uqXq1esb pS42wNQx+ucHPEi9VHmlkfCc4Cr/r1ejac6CscQxVreYJgdLawEIwOtF3dFNUR3q8coz9V 3FscCf1jYBjJVtBMuV/OERWqSAA+f/6MP5qM7VtPUjxa+WsrblguRg2TbekZ7w== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1756394908; a=rsa-sha256; cv=none; b=VcQOZdCQHZR2CpKGqgT+r7YKqGObyd26bL50fjPzIEsZXPK4KKS5wZ/IHBUsaKsWvsY5as ZMouWgIwfeNi31GkDadVEimjEdw+JB2Bc6HtqmuC+H+Fg2NNc7NynYzvSSebKia2NK897g uatq4IsAa4AbM32LpjDzFpD8nr1uRslHKaSWymoF+eDVjQUgXi3qQs3NSABv3r/QNMdhK7 DukA5URX+B4fIujV67QHh60q8YPcRxRs6e2TuxU1rr4XLaE4CaZJb/IrEiD7QBRa6CgsGM 6OrlohiyKyEzZ3CGxOH+nQtR+NOCzicIv/hKMJOVqOY+tdVFA3A27mNj7HxxMQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4cCQK83Zhwz1DZZ; Thu, 28 Aug 2025 15:28:28 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 57SFSSxA012084; Thu, 28 Aug 2025 15:28:28 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 57SFSSaR012081; Thu, 28 Aug 2025 15:28:28 GMT (envelope-from git) Date: Thu, 28 Aug 2025 15:28:28 GMT Message-Id: <202508281528.57SFSSaR012081@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: be8bae670025 - main - vfs: make vfscount refcounting handle possible kld unload List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: be8bae67002503baff6bb9fb77fbe6b80f035c33 Auto-Submitted: auto-generated The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=be8bae67002503baff6bb9fb77fbe6b80f035c33 commit be8bae67002503baff6bb9fb77fbe6b80f035c33 Author: Konstantin Belousov AuthorDate: 2025-08-27 22:24:01 +0000 Commit: Konstantin Belousov CommitDate: 2025-08-28 15:21:54 +0000 vfs: make vfscount refcounting handle possible kld unload Make the refcounting occur outside any code that might deref a pointer to struct vfsconf. Increment vfc_refcount in vfs_byname(), under vfsconf_lock. Unref either on early mount failure, before struct mount is instantiated, or in vfs_mount_destroy(). Reported and reviewed by: kevans Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week --- sys/kern/vfs_init.c | 16 ++++++++++++++-- sys/kern/vfs_mount.c | 7 +++++-- sys/sys/mount.h | 1 + 3 files changed, 20 insertions(+), 4 deletions(-) diff --git a/sys/kern/vfs_init.c b/sys/kern/vfs_init.c index cd30d5cfae47..93ac001af8ad 100644 --- a/sys/kern/vfs_init.c +++ b/sys/kern/vfs_init.c @@ -103,6 +103,16 @@ struct vattr va_null; * Routines having to do with the management of the vnode table. */ +void +vfs_unref_vfsconf(struct vfsconf *vfsp) +{ + vfsconf_lock(); + KASSERT(vfsp->vfc_refcount > 0, + ("vfs %p refcount underflow %d", vfsp, vfsp->vfc_refcount)); + vfsp->vfc_refcount--; + vfsconf_unlock(); +} + static struct vfsconf * vfs_byname_locked(const char *name) { @@ -123,9 +133,11 @@ vfs_byname(const char *name) { struct vfsconf *vfsp; - vfsconf_slock(); + vfsconf_lock(); vfsp = vfs_byname_locked(name); - vfsconf_sunlock(); + if (vfsp != NULL) + vfsp->vfc_refcount++; + vfsconf_unlock(); return (vfsp); } diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c index 8e64a7fe966b..13403acacc08 100644 --- a/sys/kern/vfs_mount.c +++ b/sys/kern/vfs_mount.c @@ -683,7 +683,6 @@ vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath, MPASSERT(mp->mnt_vfs_ops == 1, mp, ("vfs_ops should be 1 but %d found", mp->mnt_vfs_ops)); (void) vfs_busy(mp, MBF_NOWAIT); - atomic_add_acq_int(&vfsp->vfc_refcount, 1); mp->mnt_op = vfsp->vfc_vfsops; mp->mnt_vfc = vfsp; mp->mnt_stat.f_type = vfsp->vfc_typenum; @@ -731,7 +730,6 @@ vfs_mount_destroy(struct mount *mp) __FILE__, __LINE__)); MPPASS(mp->mnt_writeopcount == 0, mp); MPPASS(mp->mnt_secondary_writes == 0, mp); - atomic_subtract_rel_int(&mp->mnt_vfc->vfc_refcount, 1); if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { struct vnode *vp; @@ -769,6 +767,9 @@ vfs_mount_destroy(struct mount *mp) vfs_free_addrlist(mp->mnt_export); free(mp->mnt_export, M_MOUNT); } + vfsconf_lock(); + mp->mnt_vfc->vfc_refcount--; + vfsconf_unlock(); crfree(mp->mnt_cred); uma_zfree(mount_zone, mp); } @@ -1133,6 +1134,7 @@ vfs_domount_first( if (jailed(td->td_ucred) && (!prison_allow(td->td_ucred, vfsp->vfc_prison_flag) || vp == td->td_ucred->cr_prison->pr_root)) { vput(vp); + vfs_unref_vfsconf(vfsp); return (EPERM); } @@ -1169,6 +1171,7 @@ vfs_domount_first( } if (error != 0) { vput(vp); + vfs_unref_vfsconf(vfsp); return (error); } vn_seqc_write_begin(vp); diff --git a/sys/sys/mount.h b/sys/sys/mount.h index f6480b173a5c..18f85192f6c3 100644 --- a/sys/sys/mount.h +++ b/sys/sys/mount.h @@ -1007,6 +1007,7 @@ struct mntarg *mount_argsu(struct mntarg *ma, const char *name, const void *val, void statfs_scale_blocks(struct statfs *sf, long max_size); struct vfsconf *vfs_byname(const char *); struct vfsconf *vfs_byname_kld(const char *, struct thread *td, int *); +void vfs_unref_vfsconf(struct vfsconf *vfsp); void vfs_mount_destroy(struct mount *); void vfs_event_signal(fsid_t *, u_int32_t, intptr_t); void vfs_freeopts(struct vfsoptlist *opts);