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OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 7652B606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmx.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gmx.com header.i=quwenruo.btrfs@gmx.com header.a=rsa-sha256 header.s=s31663417 header.b=Krv3jpGL DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmx.com; s=s31663417; t=1792977234; x=1793582034; i=quwenruo.btrfs@gmx.com; bh=3tztcZ9V+WoMx5fe6Vfs+qt9l9yIbvsO2CHhZ3wz+Ac=; h=X-UI-Sender-Class:Message-ID:Date:MIME-Version:Subject:To:Cc: References:From:In-Reply-To:Content-Type: Content-Transfer-Encoding:cc:content-transfer-encoding: content-type:date:from:message-id:mime-version:reply-to:subject: to; b=Krv3jpGLWQwY+IGHxBwWuREpZkawb0Ctmk5UVICT3+sjZoDC4FRZUfHXyTBgrDtz 8bjXE928RE0P0e6s1oor3LEtp67OsgLv6w+3vYP2uWYtPqap3ivGZihQrhahrVMgo 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Mount accepts it, > and btrfs_ioctl_subvol_sync() then reaches >=20 > ASSERT(root_flags & BTRFS_ROOT_SUBVOL_DEAD, ...) >=20 > which is BUG() on CONFIG_BTRFS_ASSERT=3Dy. >=20 > Return -EUCLEAN instead of asserting, and log the inconsistent state. >=20 > The ioctl BUG was reproduced in 2/4 baseline boots (the other two lost > a race to the same image's unrelated cleaner WARN). With this change > the ioctl returns -EUCLEAN and no BUG; a normal btrfs mount/write/ > readback/check regression passes. >=20 > Assisted-by: LLM > Signed-off-by: Cheng Yongkang > --- > fs/btrfs/ioctl.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) >=20 > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 576cd76..00eab0b 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -5149,8 +5149,12 @@ static int btrfs_ioctl_subvol_sync(struct btrfs_f= s_info *fs_info, void __user *a > return -ENOENT; > =20 > wait_for_deletion =3D true; > - ASSERT(root_flags & BTRFS_ROOT_SUBVOL_DEAD, "root_flags=3D0x%llx", > - root_flags); > + if (!(root_flags & BTRFS_ROOT_SUBVOL_DEAD)) { Use unlikely(). Secondly it's still possible to hit a subvolume without DEAD flag at=20 runtime. btrfs_ioctl_snap_destroy() |- btrfs_delete_subvolume() |- btrfs_set_root_flags( | SUBVOL_DEAD) |- Some error hit, goto out_end_trans or out_undead tag |- btrfs_set_root_flags( & ~SUBVOL_DEAD) Although in that case, the transaction is already aborted, so no on-disk= =20 metadata is corrupted. Then someone can still call the ioctl on the subvolume and trigger the=20 warning. Although this is not a regression, but a pre-existing problem, I'd=20 suggest to do some writeable checks for the SYNC_WAIT ioctl. > + btrfs_err(fs_info, > + "subvol %llu has refs 0 without DEAD flag", > + args.subvolid); > + return -EUCLEAN; > + } > sched_ret =3D schedule_timeout_interruptible(HZ); > /* Early wake up or error. */ > if (sched_ret !=3D 0)