Date: Sun, 25 Jan 2026 21:39:11 +0200 From: Konstantin Belousov <kostikbel@gmail.com> To: Gleb Popov <arrowd@freebsd.org> Cc: src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 10037d0978f8 - main - fusefs: Implement support for the auto_unmount option kernel-side Message-ID: <aXZxX7UEaXqNQRt6@kib.kiev.ua> In-Reply-To: <697499a8.335a0.2e12eda1@gitrepo.freebsd.org>
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On Sat, Jan 24, 2026 at 10:06:32AM +0000, Gleb Popov wrote: > The branch main has been updated by arrowd: > > URL: https://cgit.FreeBSD.org/src/commit/?id=10037d0978f8b16dc6746b0b942788e5edc6e84f > > commit 10037d0978f8b16dc6746b0b942788e5edc6e84f > Author: Gleb Popov <arrowd@FreeBSD.org> > AuthorDate: 2025-10-14 16:15:50 +0000 > Commit: Gleb Popov <arrowd@FreeBSD.org> > CommitDate: 2026-01-24 10:06:16 +0000 > > fusefs: Implement support for the auto_unmount option kernel-side > > libfuse clients may pass the "-o auto_unmount" flag to ensure that the mountpoint > will get unmounted even if the server terminate abnormally. Without this flag > sending KILL to a FUSE daemon leaves its mountpoint mounted. > > Approved by: asomers > Differential Revision: https://reviews.freebsd.org/D53086 > --- > sbin/mount_fusefs/mount_fusefs.8 | 5 ++++- > sbin/mount_fusefs/mount_fusefs.c | 2 ++ > sys/fs/fuse/fuse_device.c | 6 +++++- > sys/fs/fuse/fuse_ipc.h | 3 ++- > sys/fs/fuse/fuse_vfsops.c | 1 + > 5 files changed, 14 insertions(+), 3 deletions(-) > > diff --git a/sbin/mount_fusefs/mount_fusefs.8 b/sbin/mount_fusefs/mount_fusefs.8 > index 44f7e029dec6..a463f6463a29 100644 > --- a/sbin/mount_fusefs/mount_fusefs.8 > +++ b/sbin/mount_fusefs/mount_fusefs.8 > @@ -32,7 +32,7 @@ > .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF > .\" SUCH DAMAGE. > .\" > -.Dd October 9, 2021 > +.Dd January 24, 2026 > .Dt MOUNT_FUSEFS 8 > .Os > .Sh NAME > @@ -171,6 +171,9 @@ to the file system name as reported by > .Xr statfs 2 . > This option can be used to identify the file system implemented by > .Ar fuse_daemon . > +.It Cm auto_unmount > +Instructs the kernel to unmount the mount point when the FUSE device gets closed. > +This ensures a proper cleanup if the FUSE daemon exits abnormally. > .El > .El > .Pp > diff --git a/sbin/mount_fusefs/mount_fusefs.c b/sbin/mount_fusefs/mount_fusefs.c > index 2d65494421ef..a4e33ad6878e 100644 > --- a/sbin/mount_fusefs/mount_fusefs.c > +++ b/sbin/mount_fusefs/mount_fusefs.c > @@ -84,6 +84,8 @@ static struct mntopt mopts[] = { > { "automounted", 0, ALTF_AUTOMOUNTED, 1 }, > #define ALTF_INTR 0x200 > { "intr", 0, ALTF_INTR, 1 }, > + #define ALTF_AUTOUNMOUNT 0x400 > + { "auto_unmount", 0, ALTF_AUTOUNMOUNT, 1 }, > /* Linux specific options, we silently ignore them */ > { "fd=", 0, 0x00, 1 }, > { "rootmode=", 0, 0x00, 1 }, > diff --git a/sys/fs/fuse/fuse_device.c b/sys/fs/fuse/fuse_device.c > index 41387de3ce71..2c1e19953dfd 100644 > --- a/sys/fs/fuse/fuse_device.c > +++ b/sys/fs/fuse/fuse_device.c > @@ -65,7 +65,6 @@ > #include <sys/module.h> > #include <sys/systm.h> > #include <sys/errno.h> > -#include <sys/param.h> > #include <sys/kernel.h> > #include <sys/conf.h> > #include <sys/uio.h> > @@ -177,6 +176,11 @@ fdata_dtor(void *arg) > fuse_lck_mtx_unlock(fdata->ms_mtx); > FUSE_UNLOCK(); > > + if (fdata->mp && fdata->dataflags & FSESS_AUTO_UNMOUNT) { if (fdata->mp != NULL && (fdata->dataflags & FSESS_AUTO_UNMOUNT) != 0) { > + vfs_ref(fdata->mp); Don't you need to take the reference when the fdata is created and mp member is initialized, and not here? What guarantees that the mp is still ours? In fact, I think that you should use vfs_busy() and not vfs_ref(), since what prevents mp from being unmounted under us? > + dounmount(fdata->mp, MNT_FORCE, curthread); > + } > + > fdata_trydestroy(fdata); > } > > diff --git a/sys/fs/fuse/fuse_ipc.h b/sys/fs/fuse/fuse_ipc.h > index d9d79f38c269..98af84951561 100644 > --- a/sys/fs/fuse/fuse_ipc.h > +++ b/sys/fs/fuse/fuse_ipc.h > @@ -242,8 +242,9 @@ struct fuse_data { > #define FSESS_WARN_INODE_MISMATCH 0x4000000 /* ino != nodeid */ > #define FSESS_MNTOPTS_MASK ( \ > FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \ > - FSESS_DEFAULT_PERMISSIONS | FSESS_INTR) > + FSESS_DEFAULT_PERMISSIONS | FSESS_INTR | FSESS_AUTO_UNMOUNT) > #define FSESS_SETXATTR_EXT 0x8000000 /* extended fuse_setxattr_in */ > +#define FSESS_AUTO_UNMOUNT 0x10000000 /* perform unmount when server dies */ > > extern int fuse_data_cache_mode; > > diff --git a/sys/fs/fuse/fuse_vfsops.c b/sys/fs/fuse/fuse_vfsops.c > index 0ff79913128a..a5118aa7675f 100644 > --- a/sys/fs/fuse/fuse_vfsops.c > +++ b/sys/fs/fuse/fuse_vfsops.c > @@ -337,6 +337,7 @@ fuse_vfsop_mount(struct mount *mp) > FUSE_FLAGOPT(push_symlinks_in, FSESS_PUSH_SYMLINKS_IN); > FUSE_FLAGOPT(default_permissions, FSESS_DEFAULT_PERMISSIONS); > FUSE_FLAGOPT(intr, FSESS_INTR); > + FUSE_FLAGOPT(auto_unmount, FSESS_AUTO_UNMOUNT); > > (void)vfs_scanopt(opts, "max_read=", "%u", &max_read); > (void)vfs_scanopt(opts, "linux_errnos", "%d", &linux_errnos);home | help
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