* Re: [patch 33/38] powerpc: Select ARCH_HAS_RANDOM_ENTROPY
From: Christophe Leroy (CS GROUP) @ 2026-04-15 6:47 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: Michael Ellerman, linuxppc-dev, Arnd Bergmann, x86, Lu Baolu,
iommu, Michael Grzeschik, netdev, linux-wireless, Herbert Xu,
linux-crypto, Vlastimil Babka, linux-mm, David Woodhouse,
Bernie Thompson, linux-fbdev, Theodore Tso, linux-ext4,
Andrew Morton, Uladzislau Rezki, Marco Elver, Dmitry Vyukov,
kasan-dev, Andrey Ryabinin, Thomas Sailer, linux-hams,
Jason A. Donenfeld, Richard Henderson, linux-alpha, Russell King,
linux-arm-kernel, Catalin Marinas, Huacai Chen, loongarch,
Geert Uytterhoeven, linux-m68k, Dinh Nguyen, Jonas Bonn,
linux-openrisc, Helge Deller, linux-parisc, Paul Walmsley,
linux-riscv, Heiko Carstens, linux-s390, David S. Miller,
sparclinux
In-Reply-To: <20260410120319.789114053@kernel.org>
Le 10/04/2026 à 14:21, Thomas Gleixner a écrit :
> The only remaining usage of get_cycles() is to provide random_get_entropy().
>
> Switch powerpc over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
> and providing random_get_entropy() in asm/random.h.
>
> Remove asm/timex.h as it has no functionality anymore.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
> ---
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/include/asm/random.h | 13 +++++++++++++
> arch/powerpc/include/asm/timex.h | 21 ---------------------
> 3 files changed, 14 insertions(+), 21 deletions(-)
>
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -150,6 +150,7 @@ config PPC
> select ARCH_HAS_PREEMPT_LAZY
> select ARCH_HAS_PTDUMP
> select ARCH_HAS_PTE_SPECIAL
> + select ARCH_HAS_RANDOM_ENTROPY
> select ARCH_HAS_SCALED_CPUTIME if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
> select ARCH_HAS_SET_MEMORY
> select ARCH_HAS_STRICT_KERNEL_RWX if (PPC_BOOK3S || PPC_8xx) && !HIBERNATION
> --- /dev/null
> +++ b/arch/powerpc/include/asm/random.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_POWERPC_RANDOM_H
> +#define _ASM_POWERPC_RANDOM_H
> +
> +#include <asm/cputable.h>
> +#include <asm/vdso/timebase.h>
> +
> +static inline unsigned long random_get_entropy(void)
> +{
> + return mftb();
> +}
> +
> +#endif /* _ASM_POWERPC_RANDOM_H */
> --- a/arch/powerpc/include/asm/timex.h
> +++ b/arch/powerpc/include/asm/timex.h
> @@ -1,21 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#ifndef _ASM_POWERPC_TIMEX_H
> -#define _ASM_POWERPC_TIMEX_H
> -
> -#ifdef __KERNEL__
> -
> -/*
> - * PowerPC architecture timex specifications
> - */
> -
> -#include <asm/cputable.h>
> -#include <asm/vdso/timebase.h>
> -
> -ostatic inline cycles_t get_cycles(void)
> -{
> - return mftb();
> -}
> -#define get_cycles get_cycles
> -
> -#endif /* __KERNEL__ */
> -#endif /* _ASM_POWERPC_TIMEX_H */
>
>
^ permalink raw reply
* Re: [patch 07/38] treewide: Consolidate cycles_t
From: Christophe Leroy (CS GROUP) @ 2026-04-15 6:43 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: Arnd Bergmann, x86, Lu Baolu, iommu, Michael Grzeschik, netdev,
linux-wireless, Herbert Xu, linux-crypto, Vlastimil Babka,
linux-mm, David Woodhouse, Bernie Thompson, linux-fbdev,
Theodore Tso, linux-ext4, Andrew Morton, Uladzislau Rezki,
Marco Elver, Dmitry Vyukov, kasan-dev, Andrey Ryabinin,
Thomas Sailer, linux-hams, Jason A. Donenfeld, Richard Henderson,
linux-alpha, Russell King, linux-arm-kernel, Catalin Marinas,
Huacai Chen, loongarch, Geert Uytterhoeven, linux-m68k,
Dinh Nguyen, Jonas Bonn, linux-openrisc, Helge Deller,
linux-parisc, Michael Ellerman, linuxppc-dev, Paul Walmsley,
linux-riscv, Heiko Carstens, linux-s390, David S. Miller,
sparclinux
In-Reply-To: <20260410120318.045532623@kernel.org>
Le 10/04/2026 à 14:19, Thomas Gleixner a écrit :
> Most architectures define cycles_t as unsigned long execpt:
>
> - x86 requires it to be 64-bit independent of the 32-bit/64-bit build.
>
> - parisc and mips define it as unsigned int
>
> parisc has no real reason to do so as there are only a few usage sites
> which either expand it to a 64-bit value or utilize only the lower
> 32bits.
>
> mips has no real requirement either.
>
> Move the typedef to types.h and provide a config switch to enforce the
> 64-bit type for x86.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> ---
> arch/Kconfig | 4 ++++
> arch/alpha/include/asm/timex.h | 3 ---
> arch/arm/include/asm/timex.h | 1 -
> arch/loongarch/include/asm/timex.h | 2 --
> arch/m68k/include/asm/timex.h | 2 --
> arch/mips/include/asm/timex.h | 2 --
> arch/nios2/include/asm/timex.h | 2 --
> arch/parisc/include/asm/timex.h | 2 --
> arch/powerpc/include/asm/timex.h | 4 +---
> arch/riscv/include/asm/timex.h | 2 --
> arch/s390/include/asm/timex.h | 2 --
> arch/sparc/include/asm/timex_64.h | 1 -
> arch/x86/Kconfig | 1 +
> arch/x86/include/asm/tsc.h | 2 --
> include/asm-generic/timex.h | 1 -
> include/linux/types.h | 6 ++++++
> 16 files changed, 12 insertions(+), 25 deletions(-)
>
> --- a/arch/powerpc/include/asm/timex.h
> +++ b/arch/powerpc/include/asm/timex.h
> @@ -11,9 +11,7 @@
> #include <asm/cputable.h>
> #include <asm/vdso/timebase.h>
>
> -typedef unsigned long cycles_t;
> -
> -static inline cycles_t get_cycles(void)
> +ostatic inline cycles_t get_cycles(void)
What is 'ostatic' ?
> {
> return mftb();
> }
^ permalink raw reply
* Re: [patch 05/38] treewide: Remove CLOCK_TICK_RATE
From: Christophe Leroy (CS GROUP) @ 2026-04-15 6:40 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: Arnd Bergmann, x86, Lu Baolu, iommu, Michael Grzeschik, netdev,
linux-wireless, Herbert Xu, linux-crypto, Vlastimil Babka,
linux-mm, David Woodhouse, Bernie Thompson, linux-fbdev,
Theodore Tso, linux-ext4, Andrew Morton, Uladzislau Rezki,
Marco Elver, Dmitry Vyukov, kasan-dev, Andrey Ryabinin,
Thomas Sailer, linux-hams, Jason A. Donenfeld, Richard Henderson,
linux-alpha, Russell King, linux-arm-kernel, Catalin Marinas,
Huacai Chen, loongarch, Geert Uytterhoeven, linux-m68k,
Dinh Nguyen, Jonas Bonn, linux-openrisc, Helge Deller,
linux-parisc, Michael Ellerman, linuxppc-dev, Paul Walmsley,
linux-riscv, Heiko Carstens, linux-s390, David S. Miller,
sparclinux
In-Reply-To: <20260410120317.910770161@kernel.org>
Le 10/04/2026 à 14:18, Thomas Gleixner a écrit :
> This has been scheduled for removal more than a decade ago and the comments
> related to it have been dutifully ignored. The last dependencies are gone.
>
> Remove it along with various now empty asm/timex.h files.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
For powerpc:
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
> ---
> arch/alpha/include/asm/timex.h | 4 ----
> arch/arc/include/asm/timex.h | 15 ---------------
> arch/arm/mach-omap1/Kconfig | 2 +-
> arch/hexagon/include/asm/timex.h | 3 ---
> arch/m68k/include/asm/timex.h | 15 ---------------
> arch/microblaze/include/asm/timex.h | 13 -------------
> arch/mips/include/asm/timex.h | 8 --------
> arch/openrisc/include/asm/timex.h | 3 ---
> arch/parisc/include/asm/timex.h | 2 --
> arch/powerpc/include/asm/timex.h | 2 --
> arch/s390/include/asm/timex.h | 2 --
> arch/sh/include/asm/timex.h | 24 ------------------------
> arch/sparc/include/asm/timex.h | 2 +-
> arch/sparc/include/asm/timex_32.h | 14 --------------
> arch/sparc/include/asm/timex_64.h | 2 --
> arch/um/include/asm/timex.h | 9 ---------
> arch/x86/include/asm/timex.h | 3 ---
> 17 files changed, 2 insertions(+), 121 deletions(-)
>
> --- a/arch/alpha/include/asm/timex.h
> +++ b/arch/alpha/include/asm/timex.h
> @@ -7,10 +7,6 @@
> #ifndef _ASMALPHA_TIMEX_H
> #define _ASMALPHA_TIMEX_H
>
> -/* With only one or two oddballs, we use the RTC as the ticker, selecting
> - the 32.768kHz reference clock, which nicely divides down to our HZ. */
> -#define CLOCK_TICK_RATE 32768
> -
> /*
> * Standard way to access the cycle counter.
> * Currently only used on SMP for scheduling.
> --- a/arch/arc/include/asm/timex.h
> +++ /dev/null
> @@ -1,15 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0-only */
> -/*
> - * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.synopsys.com%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7Cac13d5b928bc4eabd9b708de96fb5935%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639114203455047148%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=uCL895qVLUoy3Stzhmgph2DiYmjpd4RPdQIW2dZcJ7w%3D&reserved=0)
> - */
> -
> -#ifndef _ASM_ARC_TIMEX_H
> -#define _ASM_ARC_TIMEX_H
> -
> -#define CLOCK_TICK_RATE 80000000 /* slated to be removed */
> -
> -#include <asm-generic/timex.h>
> -
> -/* XXX: get_cycles() to be implemented with RTSC insn */
> -
> -#endif /* _ASM_ARC_TIMEX_H */
> --- a/arch/arm/mach-omap1/Kconfig
> +++ b/arch/arm/mach-omap1/Kconfig
> @@ -74,7 +74,7 @@ config OMAP_32K_TIMER
> currently only available for OMAP16XX, 24XX, 34XX, OMAP4/5 and DRA7XX.
>
> On OMAP2PLUS this value is only used for CONFIG_HZ and
> - CLOCK_TICK_RATE compile time calculation.
> + timer frequency compile time calculation.
> The actual timer selection is done in the board file
> through the (DT_)MACHINE_START structure.
>
> --- a/arch/hexagon/include/asm/timex.h
> +++ b/arch/hexagon/include/asm/timex.h
> @@ -9,9 +9,6 @@
> #include <asm-generic/timex.h>
> #include <asm/hexagon_vm.h>
>
> -/* Using TCX0 as our clock. CLOCK_TICK_RATE scheduled to be removed. */
> -#define CLOCK_TICK_RATE 19200
> -
> #define ARCH_HAS_READ_CURRENT_TIMER
>
> static inline int read_current_timer(unsigned long *timer_val)
> --- a/arch/m68k/include/asm/timex.h
> +++ b/arch/m68k/include/asm/timex.h
> @@ -7,21 +7,6 @@
> #ifndef _ASMm68K_TIMEX_H
> #define _ASMm68K_TIMEX_H
>
> -#ifdef CONFIG_COLDFIRE
> -/*
> - * CLOCK_TICK_RATE should give the underlying frequency of the tick timer
> - * to make ntp work best. For Coldfires, that's the main clock.
> - */
> -#include <asm/coldfire.h>
> -#define CLOCK_TICK_RATE MCF_CLK
> -#else
> -/*
> - * This default CLOCK_TICK_RATE is probably wrong for many 68k boards
> - * Users of those boards will need to check and modify accordingly
> - */
> -#define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
> -#endif
> -
> typedef unsigned long cycles_t;
>
> static inline cycles_t get_cycles(void)
> --- a/arch/microblaze/include/asm/timex.h
> +++ /dev/null
> @@ -1,13 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -/*
> - * Copyright (C) 2006 Atmark Techno, Inc.
> - */
> -
> -#ifndef _ASM_MICROBLAZE_TIMEX_H
> -#define _ASM_MICROBLAZE_TIMEX_H
> -
> -#include <asm-generic/timex.h>
> -
> -#define CLOCK_TICK_RATE 1000 /* Timer input freq. */
> -
> -#endif /* _ASM_TIMEX_H */
> --- a/arch/mips/include/asm/timex.h
> +++ b/arch/mips/include/asm/timex.h
> @@ -19,14 +19,6 @@
> #include <asm/cpu-type.h>
>
> /*
> - * This is the clock rate of the i8253 PIT. A MIPS system may not have
> - * a PIT by the symbol is used all over the kernel including some APIs.
> - * So keeping it defined to the number for the PIT is the only sane thing
> - * for now.
> - */
> -#define CLOCK_TICK_RATE 1193182
> -
> -/*
> * Standard way to access the cycle counter.
> * Currently only used on SMP for scheduling.
> *
> --- a/arch/openrisc/include/asm/timex.h
> +++ b/arch/openrisc/include/asm/timex.h
> @@ -25,9 +25,6 @@ static inline cycles_t get_cycles(void)
> }
> #define get_cycles get_cycles
>
> -/* This isn't really used any more */
> -#define CLOCK_TICK_RATE 1000
> -
> #define ARCH_HAS_READ_CURRENT_TIMER
>
> #endif
> --- a/arch/parisc/include/asm/timex.h
> +++ b/arch/parisc/include/asm/timex.h
> @@ -9,8 +9,6 @@
>
> #include <asm/special_insns.h>
>
> -#define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
> -
> typedef unsigned long cycles_t;
>
> static inline cycles_t get_cycles(void)
> --- a/arch/powerpc/include/asm/timex.h
> +++ b/arch/powerpc/include/asm/timex.h
> @@ -11,8 +11,6 @@
> #include <asm/cputable.h>
> #include <asm/vdso/timebase.h>
>
> -#define CLOCK_TICK_RATE 1024000 /* Underlying HZ */
> -
> typedef unsigned long cycles_t;
>
> static inline cycles_t get_cycles(void)
> --- a/arch/s390/include/asm/timex.h
> +++ b/arch/s390/include/asm/timex.h
> @@ -177,8 +177,6 @@ static inline void local_tick_enable(uns
> set_clock_comparator(get_lowcore()->clock_comparator);
> }
>
> -#define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
> -
> typedef unsigned long cycles_t;
>
> static __always_inline unsigned long get_tod_clock(void)
> --- a/arch/sh/include/asm/timex.h
> +++ /dev/null
> @@ -1,24 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -/*
> - * linux/include/asm-sh/timex.h
> - *
> - * sh architecture timex specifications
> - */
> -#ifndef __ASM_SH_TIMEX_H
> -#define __ASM_SH_TIMEX_H
> -
> -/*
> - * Only parts using the legacy CPG code for their clock framework
> - * implementation need to define their own Pclk value. If provided, this
> - * can be used for accurately setting CLOCK_TICK_RATE, otherwise we
> - * simply fall back on the i8253 PIT value.
> - */
> -#ifdef CONFIG_SH_PCLK_FREQ
> -#define CLOCK_TICK_RATE (CONFIG_SH_PCLK_FREQ / 4) /* Underlying HZ */
> -#else
> -#define CLOCK_TICK_RATE 1193180
> -#endif
> -
> -#include <asm-generic/timex.h>
> -
> -#endif /* __ASM_SH_TIMEX_H */
> --- a/arch/sparc/include/asm/timex.h
> +++ b/arch/sparc/include/asm/timex.h
> @@ -4,6 +4,6 @@
> #if defined(__sparc__) && defined(__arch64__)
> #include <asm/timex_64.h>
> #else
> -#include <asm/timex_32.h>
> +#include <asm-generic/timex.h>
> #endif
> #endif
> --- a/arch/sparc/include/asm/timex_32.h
> +++ /dev/null
> @@ -1,14 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -/*
> - * linux/include/asm/timex.h
> - *
> - * sparc architecture timex specifications
> - */
> -#ifndef _ASMsparc_TIMEX_H
> -#define _ASMsparc_TIMEX_H
> -
> -#define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
> -
> -#include <asm-generic/timex.h>
> -
> -#endif
> --- a/arch/sparc/include/asm/timex_64.h
> +++ b/arch/sparc/include/asm/timex_64.h
> @@ -9,8 +9,6 @@
>
> #include <asm/timer.h>
>
> -#define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
> -
> /* Getting on the cycle counter on sparc64. */
> typedef unsigned long cycles_t;
> #define get_cycles() tick_ops->get_tick()
> --- a/arch/um/include/asm/timex.h
> +++ /dev/null
> @@ -1,9 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#ifndef __UM_TIMEX_H
> -#define __UM_TIMEX_H
> -
> -#define CLOCK_TICK_RATE (HZ)
> -
> -#include <asm-generic/timex.h>
> -
> -#endif
> --- a/arch/x86/include/asm/timex.h
> +++ b/arch/x86/include/asm/timex.h
> @@ -14,9 +14,6 @@ static inline unsigned long random_get_e
> }
> #define random_get_entropy random_get_entropy
>
> -/* Assume we use the PIT time source for the clock tick */
> -#define CLOCK_TICK_RATE PIT_TICK_RATE
> -
> #define ARCH_HAS_READ_CURRENT_TIMER
>
> #endif /* _ASM_X86_TIMEX_H */
>
>
^ permalink raw reply
* Re: [patch 32/38] powerpc/spufs: Use mftb() directly
From: Christophe Leroy (CS GROUP) @ 2026-04-15 6:38 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: Michael Ellerman, linuxppc-dev, Arnd Bergmann, x86, Lu Baolu,
iommu, Michael Grzeschik, netdev, linux-wireless, Herbert Xu,
linux-crypto, Vlastimil Babka, linux-mm, David Woodhouse,
Bernie Thompson, linux-fbdev, Theodore Tso, linux-ext4,
Andrew Morton, Uladzislau Rezki, Marco Elver, Dmitry Vyukov,
kasan-dev, Andrey Ryabinin, Thomas Sailer, linux-hams,
Jason A. Donenfeld, Richard Henderson, linux-alpha, Russell King,
linux-arm-kernel, Catalin Marinas, Huacai Chen, loongarch,
Geert Uytterhoeven, linux-m68k, Dinh Nguyen, Jonas Bonn,
linux-openrisc, Helge Deller, linux-parisc, Paul Walmsley,
linux-riscv, Heiko Carstens, linux-s390, David S. Miller,
sparclinux
In-Reply-To: <20260410120319.723429844@kernel.org>
Le 10/04/2026 à 14:21, Thomas Gleixner a écrit :
> There is no reason to indirect via get_cycles(), which is about to be
> removed.
>
> Use mftb() directly.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
> ---
> arch/powerpc/platforms/cell/spufs/switch.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> --- a/arch/powerpc/platforms/cell/spufs/switch.c
> +++ b/arch/powerpc/platforms/cell/spufs/switch.c
> @@ -34,6 +34,7 @@
> #include <asm/spu_priv1.h>
> #include <asm/spu_csa.h>
> #include <asm/mmu_context.h>
> +#include <asm/time.h>
>
> #include "spufs.h"
>
> @@ -279,7 +280,7 @@ static inline void save_timebase(struct
> * Read PPE Timebase High and Timebase low registers
> * and save in CSA. TBD.
> */
> - csa->suspend_time = get_cycles();
> + csa->suspend_time = mftb();
> }
>
> static inline void remove_other_spu_access(struct spu_state *csa,
> @@ -1261,7 +1262,7 @@ static inline void setup_decr(struct spu
> * in LSCSA.
> */
> if (csa->priv2.mfc_control_RW & MFC_CNTL_DECREMENTER_RUNNING) {
> - cycles_t resume_time = get_cycles();
> + cycles_t resume_time = mftb();
> cycles_t delta_time = resume_time - csa->suspend_time;
>
> csa->lscsa->decr_status.slot[0] = SPU_DECR_STATUS_RUNNING;
>
>
^ permalink raw reply
* Re: [PATCH v7 03/22] ovl: use core fsverity ensure info interface
From: Christoph Hellwig @ 2026-04-15 5:23 UTC (permalink / raw)
To: Andrey Albershteyn
Cc: Christoph Hellwig, Andrey Albershteyn, linux-xfs, fsverity,
linux-fsdevel, ebiggers, linux-ext4, linux-f2fs-devel,
linux-btrfs, djwong
In-Reply-To: <u3szxuhjrv7vyxwyrepuflwhzeucss7xj3cxj73mnpm5kal2da@jck24ig4oxxa>
On Tue, Apr 14, 2026 at 03:53:36PM +0200, Andrey Albershteyn wrote:
> > > + if (fsverity_active(inode))
> > > + fsverity_ensure_verity_info(inode);
> >
> > fsverity_ensure_verity_info already is a no-op for !fsverity_active,
> > so the check could be remove.
>
> I don't think it is. For non-fsverity inodes it will try to call into
> descriptor reading callback and fail.
You're right, sorry for the noise.
^ permalink raw reply
* Re: [PATCH v7 03/22] ovl: use core fsverity ensure info interface
From: Andrey Albershteyn @ 2026-04-14 13:53 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Andrey Albershteyn, linux-xfs, fsverity, linux-fsdevel, ebiggers,
linux-ext4, linux-f2fs-devel, linux-btrfs, djwong
In-Reply-To: <20260414081301.GB11138@lst.de>
On 2026-04-14 10:13:01, Christoph Hellwig wrote:
> On Thu, Apr 09, 2026 at 03:13:35PM +0200, Andrey Albershteyn wrote:
> > - if (!fsverity_active(inode) && IS_VERITY(inode)) {
> > - /*
> > - * If this inode was not yet opened, the verity info hasn't been
> > - * loaded yet, so we need to do that here to force it into memory.
> > - */
> > - filp = kernel_file_open(datapath, O_RDONLY, current_cred());
> > - if (IS_ERR(filp))
> > - return PTR_ERR(filp);
> > - fput(filp);
> > - }
> > + if (fsverity_active(inode))
> > + fsverity_ensure_verity_info(inode);
>
> fsverity_ensure_verity_info already is a no-op for !fsverity_active,
> so the check could be remove.
I don't think it is. For non-fsverity inodes it will try to call into
descriptor reading callback and fail.
> Also we should probably propagate the
> error return from fsverity_ensure_verity_info here.
oh right, thanks!
--
- Andrey
^ permalink raw reply
* Re: [PATCH] jbd2: enforce power-of-two default revoke hash size at compile time
From: Jan Kara @ 2026-04-14 12:59 UTC (permalink / raw)
To: Milos Nikic; +Cc: jack, tytso, linux-ext4, linux-kernel
In-Reply-To: <20260413212724.127035-1-nikic.milos@gmail.com>
On Mon 13-04-26 14:27:24, Milos Nikic wrote:
> The jbd2 revoke table relies on bitwise AND operations for fast hash
> indexing, which requires the hash table size to be a strict power of two.
>
> Currently, this requirement is only enforced at runtime via a J_ASSERT
> in jbd2_journal_init_revoke(). While this successfully catches invalid
> dynamic allocations, it means a developer accidentally modifying the
> hardcoded JOURNAL_REVOKE_DEFAULT_HASH macro will experience a system
> panic upon mounting the filesystem during testing.
>
> Add a BUILD_BUG_ON() in journal_init_common() to validate the default
> macro at compile time. This acts as an immediate, zero-overhead
> safeguard, preventing compilation entirely if the default hash size is
> mathematically invalid.
>
> Signed-off-by: Milos Nikic <nikic.milos@gmail.com>
Eh, if you modify JOURNAL_REVOKE_DEFAULT_HASH you should better know what
you are doing and if you mess up, then the kernel failing with assertion
isn't that difficult to diagnose. So sorry I don't think this "cleanup" is
useful either.
Honza
> ---
> fs/jbd2/journal.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index 4f397fcdb13c..62b36a2fc4e2 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -1565,6 +1565,7 @@ static journal_t *journal_init_common(struct block_device *bdev,
> /* The journal is marked for error until we succeed with recovery! */
> journal->j_flags = JBD2_ABORT;
>
> + BUILD_BUG_ON(!is_power_of_2(JOURNAL_REVOKE_DEFAULT_HASH));
> /* Set up a default-sized revoke table for the new mount. */
> err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
> if (err)
> --
> 2.53.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply
* Re: [PATCH] jbd2: validate transaction state before dropping from journal
From: Jan Kara @ 2026-04-14 12:46 UTC (permalink / raw)
To: Milos Nikic; +Cc: jack, tytso, linux-ext4, linux-kernel
In-Reply-To: <20260413180824.126739-1-nikic.milos@gmail.com>
On Mon 13-04-26 11:08:24, Milos Nikic wrote:
> Currently, __jbd2_journal_drop_transaction() unlinks the transaction
> from the journal's checkpoint lists and only then proceeds to validate the
> transaction's internal state using a series of J_ASSERTs.
>
> There is no need to 'mutate before validate'. If we are going to halt the
> system that makes manipulating corrupted pointers in memory irrelevant.
>
> Move the state validation block above the pointer manipulation. This
> ensures the transaction is entirely valid before modifying the journal's
> internal lists, modernizing the function's logic and paving the way
> for future graceful degradation of these assertions.
Either you have a poetry gift or you should tell your AI agent to keep the
tone more to the point :). Anyway I think this is really just a pointless
churn as it doesn't really matter whether we crash the kernel one way or
another...
Honza
>
> Signed-off-by: Milos Nikic <nikic.milos@gmail.com>
> ---
> fs/jbd2/checkpoint.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
> index 1508e2f54462..c82b6bedd27b 100644
> --- a/fs/jbd2/checkpoint.c
> +++ b/fs/jbd2/checkpoint.c
> @@ -703,6 +703,15 @@ void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transact
> {
> assert_spin_locked(&journal->j_list_lock);
>
> + J_ASSERT(transaction->t_state == T_FINISHED);
> + J_ASSERT(transaction->t_buffers == NULL);
> + J_ASSERT(transaction->t_forget == NULL);
> + J_ASSERT(transaction->t_shadow_list == NULL);
> + J_ASSERT(transaction->t_checkpoint_list == NULL);
> + J_ASSERT(atomic_read(&transaction->t_updates) == 0);
> + J_ASSERT(journal->j_committing_transaction != transaction);
> + J_ASSERT(journal->j_running_transaction != transaction);
> +
> journal->j_shrink_transaction = NULL;
> if (transaction->t_cpnext) {
> transaction->t_cpnext->t_cpprev = transaction->t_cpprev;
> @@ -714,15 +723,6 @@ void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transact
> journal->j_checkpoint_transactions = NULL;
> }
>
> - J_ASSERT(transaction->t_state == T_FINISHED);
> - J_ASSERT(transaction->t_buffers == NULL);
> - J_ASSERT(transaction->t_forget == NULL);
> - J_ASSERT(transaction->t_shadow_list == NULL);
> - J_ASSERT(transaction->t_checkpoint_list == NULL);
> - J_ASSERT(atomic_read(&transaction->t_updates) == 0);
> - J_ASSERT(journal->j_committing_transaction != transaction);
> - J_ASSERT(journal->j_running_transaction != transaction);
> -
> trace_jbd2_drop_transaction(journal, transaction);
>
> jbd2_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);
> --
> 2.53.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply
* Re: [patch 31/38] parisc: Select ARCH_HAS_RANDOM_ENTROPY
From: Helge Deller @ 2026-04-14 12:41 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: linux-parisc, Arnd Bergmann, x86, Lu Baolu, iommu,
Michael Grzeschik, netdev, linux-wireless, Herbert Xu,
linux-crypto, Vlastimil Babka, linux-mm, David Woodhouse,
Bernie Thompson, linux-fbdev, Theodore Tso, linux-ext4,
Andrew Morton, Uladzislau Rezki, Marco Elver, Dmitry Vyukov,
kasan-dev, Andrey Ryabinin, Thomas Sailer, linux-hams,
Jason A. Donenfeld, Richard Henderson, linux-alpha, Russell King,
linux-arm-kernel, Catalin Marinas, Huacai Chen, loongarch,
Geert Uytterhoeven, linux-m68k, Dinh Nguyen, Jonas Bonn,
linux-openrisc, Michael Ellerman, linuxppc-dev, Paul Walmsley,
linux-riscv, Heiko Carstens, linux-s390, David S. Miller,
sparclinux
In-Reply-To: <20260410120319.658485572@kernel.org>
On 4/10/26 14:21, Thomas Gleixner wrote:
> The only remaining non-architecture usage of get_cycles() is to provide
> random_get_entropy().
>
> Switch parisc over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
> and providing random_get_entropy() in asm/random.h.
>
> Add 'asm/timex.h' includes to the relevant files, so the global include can
> be removed once all architectures are converted over.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: Helge Deller <deller@gmx.de>
> Cc: linux-parisc@vger.kernel.org
> ---
> arch/parisc/Kconfig | 1 +
> arch/parisc/include/asm/random.h | 12 ++++++++++++
> arch/parisc/include/asm/timex.h | 6 ------
> arch/parisc/kernel/processor.c | 1 +
> arch/parisc/kernel/time.c | 1 +
> 5 files changed, 15 insertions(+), 6 deletions(-)
I tested this series on parisc.
Works as expected.
Tested-by: Helge Deller <deller@gmx.de>
Thanks!
Helge
^ permalink raw reply
* [RFC PATCH] iomap: add fast read path for small direct I/O
From: Fengnan Chang @ 2026-04-14 12:26 UTC (permalink / raw)
To: brauner, djwong, linux-xfs, linux-fsdevel, linux-ext4
Cc: lidiangang, Fengnan Chang
When running 4K random read workloads on high-performance Gen5 NVMe
SSDs, the software overhead in the iomap direct I/O path
(__iomap_dio_rw) becomes a significant bottleneck.
Using io_uring with poll mode for a 4K randread test on a raw block
device:
taskset -c 30 ./t/io_uring -p1 -d512 -b4096 -s32 -c32 -F1 -B1 -R1 -X1
-n1 -P1 /dev/nvme10n1
Result: ~3.2M IOPS
Running the exact same workload on ext4 and XFS:
taskset -c 30 ./t/io_uring -p1 -d512 -b4096 -s32 -c32 -F1 -B1 -R1 -X1
-n1 -P1 /mnt/testfile
Result: ~1.9M IOPS
Profiling the ext4 workload reveals that a significant portion of CPU
time is spent on memory allocation and the iomap state machine
iteration:
5.33% [kernel] [k] __iomap_dio_rw
3.26% [kernel] [k] iomap_iter
2.37% [kernel] [k] iomap_dio_bio_iter
2.35% [kernel] [k] kfree
1.33% [kernel] [k] iomap_dio_complete
I attempted several incremental optimizations in the __iomap_dio_rw()
path to close the gap:
1. Allocating the `bio` and `struct iomap_dio` together to avoid a
separate kmalloc. However, because `struct iomap_dio` is relatively
large and the main path is complex, this yielded almost no
performance improvement.
2. Reducing unnecessary state resets in the iomap state machine (e.g.,
skipping `iomap_iter_reset_iomap` where safe). This provided a ~5%
IOPS boost, which is helpful but still falls far short of closing
the gap with the raw block device.
Since optimizing the heavy generic path did not yield the desired
results for this specific, highly-demanding Gen5 SSD scenario, this
RFC patch introduces a dedicated asynchronous fast path.
The fast path is triggered when the request satisfies:
- Asynchronous READ request only for now.
- I/O size is <= inode blocksize (fits in a single block, no splits).
- Aligned to the block device's logical block size.
- No bounce buffering, fscrypt, or fsverity involved.
- No custom `iomap_dio_ops` (dops) registered by the filesystem.
By using a dedicated bio_set (`iomap_dio_fast_read_pool`) to embed a
much smaller completion state (`struct iomap_dio_fast_read`) directly
in the bio's front padding, we completely eliminate kmalloc/kfree and
drastically shorten the execution path.
After this optimization, the heavy generic functions disappear from the
profile, replaced by a single streamlined execution path:
4.83% [kernel] [k] iomap_dio_fast_read_async.isra.31
With this patch, 4K random read IOPS on ext4 increases from 1.9M to
2.3M.
I am aware that adding a completely separate fast path introduces
duplicate code and may result in iomap_begin being called twice, this
likely unacceptable for merging in its current form.
However, I am submitting this patch to validate whether this
optimization direction is correct and worth pursuing. I would appreciate
feedback on how to better integrate these ideas into the main iomap
execution path.
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
---
fs/iomap/direct-io.c | 275 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 275 insertions(+)
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index e911daedff65a..e4183f7c2f962 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -5,10 +5,14 @@
*/
#include <linux/blk-crypto.h>
#include <linux/fscrypt.h>
+#include <linux/fsverity.h>
#include <linux/pagemap.h>
#include <linux/iomap.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/fserror.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/init.h>
#include "internal.h"
#include "trace.h"
@@ -880,12 +884,231 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
}
EXPORT_SYMBOL_GPL(__iomap_dio_rw);
+static bool iomap_dio_fast_read_enabled = true;
+
+struct iomap_dio_fast_read {
+ struct kiocb *iocb;
+ size_t size;
+ bool should_dirty;
+ struct work_struct work;
+ struct bio bio ____cacheline_aligned_in_smp;
+};
+
+static struct bio_set iomap_dio_fast_read_pool;
+
+static void iomap_dio_fast_read_complete_work(struct work_struct *work)
+{
+ struct iomap_dio_fast_read *fr =
+ container_of(work, struct iomap_dio_fast_read, work);
+ struct kiocb *iocb = fr->iocb;
+ struct inode *inode = file_inode(iocb->ki_filp);
+ bool should_dirty = fr->should_dirty;
+ struct bio *bio = &fr->bio;
+ ssize_t ret;
+
+ WRITE_ONCE(iocb->private, NULL);
+
+ if (likely(!bio->bi_status)) {
+ ret = fr->size;
+ iocb->ki_pos += ret;
+ } else {
+ ret = blk_status_to_errno(bio->bi_status);
+ fserror_report_io(inode, FSERR_DIRECTIO_READ, iocb->ki_pos,
+ fr->size, ret, GFP_NOFS);
+ }
+
+ if (should_dirty) {
+ bio_check_pages_dirty(bio);
+ } else {
+ bio_release_pages(bio, false);
+ bio_put(bio);
+ }
+
+ inode_dio_end(inode);
+
+ trace_iomap_dio_complete(iocb, ret < 0 ? ret : 0, ret > 0 ? ret : 0);
+ iocb->ki_complete(iocb, ret);
+}
+
+static void iomap_dio_fast_read_end_io(struct bio *bio)
+{
+ struct iomap_dio_fast_read *fr = bio->bi_private;
+ struct kiocb *iocb = fr->iocb;
+
+ if (unlikely(bio->bi_status)) {
+ struct inode *inode = file_inode(iocb->ki_filp);
+
+ INIT_WORK(&fr->work, iomap_dio_fast_read_complete_work);
+ queue_work(inode->i_sb->s_dio_done_wq, &fr->work);
+ return;
+ }
+
+ iomap_dio_fast_read_complete_work(&fr->work);
+}
+
+static inline bool iomap_dio_fast_read_supported(struct kiocb *iocb,
+ struct iov_iter *iter,
+ unsigned int dio_flags,
+ size_t done_before)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ size_t count = iov_iter_count(iter);
+ unsigned int alignment;
+
+ if (!iomap_dio_fast_read_enabled)
+ return false;
+ if (iov_iter_rw(iter) != READ)
+ return false;
+
+ /*
+ * Fast read is an optimization for small IO. Filter out large IO early
+ * as it's the most common case to fail for typical direct IO workloads.
+ */
+ if (count > inode->i_sb->s_blocksize)
+ return false;
+
+ if (is_sync_kiocb(iocb) || done_before)
+ return false;
+ if (dio_flags & (IOMAP_DIO_FORCE_WAIT | IOMAP_DIO_BOUNCE))
+ return false;
+ if (iocb->ki_pos + count > i_size_read(inode))
+ return false;
+ if (IS_ENCRYPTED(inode) || fsverity_active(inode))
+ return false;
+
+ if (count < bdev_logical_block_size(inode->i_sb->s_bdev))
+ return false;
+
+ if (dio_flags & IOMAP_DIO_FSBLOCK_ALIGNED)
+ alignment = i_blocksize(inode);
+ else
+ alignment = bdev_logical_block_size(inode->i_sb->s_bdev);
+
+ if ((iocb->ki_pos | count) & (alignment - 1))
+ return false;
+
+ return true;
+}
+
+static ssize_t iomap_dio_fast_read_async(struct kiocb *iocb,
+ struct iov_iter *iter,
+ const struct iomap_ops *ops,
+ void *private)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ size_t count = iov_iter_count(iter);
+ int nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
+ bool should_dirty = user_backed_iter(iter);
+ struct iomap_dio_fast_read *fr;
+ struct iomap_iter iomi = {
+ .inode = inode,
+ .pos = iocb->ki_pos,
+ .len = count,
+ .flags = IOMAP_DIRECT,
+ .private = private,
+ };
+ struct bio *bio;
+ ssize_t ret;
+
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ iomi.flags |= IOMAP_NOWAIT;
+
+ ret = kiocb_write_and_wait(iocb, count);
+ if (ret)
+ return ret;
+
+ inode_dio_begin(inode);
+
+ ret = ops->iomap_begin(inode, iomi.pos, count, iomi.flags,
+ &iomi.iomap, &iomi.srcmap);
+ if (ret) {
+ inode_dio_end(inode);
+ return ret;
+ }
+
+ if (iomi.iomap.type != IOMAP_MAPPED ||
+ iomi.iomap.offset > iomi.pos ||
+ iomi.iomap.offset + iomi.iomap.length < iomi.pos + count ||
+ (iomi.iomap.flags & IOMAP_F_ANON_WRITE)) {
+ ret = -EAGAIN;
+ goto out_iomap_end;
+ }
+
+ if (!inode->i_sb->s_dio_done_wq) {
+ ret = sb_init_dio_done_wq(inode->i_sb);
+ if (ret < 0)
+ goto out_iomap_end;
+ }
+
+ trace_iomap_dio_rw_begin(iocb, iter, 0, 0);
+
+ bio = bio_alloc_bioset(iomi.iomap.bdev, nr_pages,
+ REQ_OP_READ | REQ_SYNC | REQ_IDLE,
+ GFP_KERNEL, &iomap_dio_fast_read_pool);
+ fr = container_of(bio, struct iomap_dio_fast_read, bio);
+ fr->iocb = iocb;
+ fr->should_dirty = should_dirty;
+
+ bio->bi_iter.bi_sector = iomap_sector(&iomi.iomap, iomi.pos);
+ bio->bi_ioprio = iocb->ki_ioprio;
+ bio->bi_private = fr;
+ bio->bi_end_io = iomap_dio_fast_read_end_io;
+
+ ret = bio_iov_iter_get_pages(bio, iter,
+ bdev_logical_block_size(iomi.iomap.bdev) - 1);
+ if (unlikely(ret)) {
+ bio_put(bio);
+ goto out_iomap_end;
+ }
+
+ if (bio->bi_iter.bi_size != count) {
+ iov_iter_revert(iter, bio->bi_iter.bi_size);
+ bio_release_pages(bio, false);
+ bio_put(bio);
+ ret = -EAGAIN;
+ goto out_iomap_end;
+ }
+
+ fr->size = bio->bi_iter.bi_size;
+
+ if (should_dirty)
+ bio_set_pages_dirty(bio);
+
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ bio->bi_opf |= REQ_NOWAIT;
+ if (iocb->ki_flags & IOCB_HIPRI) {
+ bio->bi_opf |= REQ_POLLED;
+ bio_set_polled(bio, iocb);
+ WRITE_ONCE(iocb->private, bio);
+ }
+ submit_bio(bio);
+
+ if (ops->iomap_end)
+ ops->iomap_end(inode, iomi.pos, count, count, iomi.flags,
+ &iomi.iomap);
+ return -EIOCBQUEUED;
+
+out_iomap_end:
+ if (ops->iomap_end)
+ ops->iomap_end(inode, iomi.pos, count, 0, iomi.flags,
+ &iomi.iomap);
+ inode_dio_end(inode);
+ return ret;
+}
+
ssize_t
iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
unsigned int dio_flags, void *private, size_t done_before)
{
struct iomap_dio *dio;
+ ssize_t ret;
+
+ if (!dops && iomap_dio_fast_read_supported(iocb, iter, dio_flags, done_before)) {
+ ret = iomap_dio_fast_read_async(iocb, iter, ops, private);
+ if (ret != -EAGAIN)
+ return ret;
+ }
dio = __iomap_dio_rw(iocb, iter, ops, dops, dio_flags, private,
done_before);
@@ -894,3 +1117,55 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
return iomap_dio_complete(dio);
}
EXPORT_SYMBOL_GPL(iomap_dio_rw);
+
+static ssize_t fast_read_enable_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%d\n", iomap_dio_fast_read_enabled);
+}
+
+static ssize_t fast_read_enable_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ bool enable;
+ int ret;
+
+ ret = kstrtobool(buf, &enable);
+ if (ret)
+ return ret;
+
+ iomap_dio_fast_read_enabled = enable;
+ return count;
+}
+
+static struct kobj_attribute fast_read_enable_attr =
+ __ATTR(fast_read_enable, 0644, fast_read_enable_show, fast_read_enable_store);
+
+static struct kobject *iomap_kobj;
+
+static int __init iomap_dio_sysfs_init(void)
+{
+ int ret;
+
+ ret = bioset_init(&iomap_dio_fast_read_pool, 4,
+ offsetof(struct iomap_dio_fast_read, bio),
+ BIOSET_NEED_BVECS | BIOSET_PERCPU_CACHE);
+ if (ret)
+ return ret;
+
+ iomap_kobj = kobject_create_and_add("iomap", fs_kobj);
+ if (!iomap_kobj) {
+ bioset_exit(&iomap_dio_fast_read_pool);
+ return -ENOMEM;
+ }
+
+ if (sysfs_create_file(iomap_kobj, &fast_read_enable_attr.attr)) {
+ kobject_put(iomap_kobj);
+ bioset_exit(&iomap_dio_fast_read_pool);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+fs_initcall(iomap_dio_sysfs_init);
--
2.39.5 (Apple Git-154)
^ permalink raw reply related
* Re: [PATCH v1] ext4: add mb_stats_clear for mballoc statistics
From: liubaolin @ 2026-04-14 10:07 UTC (permalink / raw)
To: tytso, adilger.kernel; +Cc: linux-ext4, linux-kernel, wangguanyu, Baolin Liu
In-Reply-To: <20260414100212.95209-1-liubaolin12138@163.com>
> Dear all,
> I have sent a small ext4 patch to add a manual reset capability for the mballoc statistics, and I would like to add some background on the motivation.
>
> The idea came mainly from XFS stats_clear.
> ext4 already exports mballoc runtime statistics through /proc/fs/ext4/<dev>/mb_stats,
> but these counters keep accumulating from mount time, which makes it inconvenient when trying to observe allocator behavior for a single test run.
>
> This patch adds a write-only sysfs node, /sys/fs/ext4/<dev>/mb_stats_clear, so that writing 1 to it resets the ext4 mballoc runtime statistics.
> It also adds sbi->s_bal_allocated to /proc/fs/ext4/<dev>/mb_stats,
> so that the proc output matches the mballoc summary printed at unmount time and the set of counters covered by mb_stats_clear is more complete.
>
> The main goal is to make it easier to observe allocator activity for a specific test run instead of relying on counters accumulated since mount.
> With this in place, the counters can be cleared before starting a test, and the resulting mb_stats output reflects only the activity generated by that test.
>
> The counters being cleared are runtime mballoc statistics used for /proc/fs/ext4/<dev>/mb_stats reporting and for the mballoc summary printed at unmount time.
> I did not find any cases where these fields are read back to drive ext4 behavior, so the reset only affects statistics reporting.
>
> For validation, /sys/fs/ext4/<dev>/mb_stats can be enabled first,
> then a file operation test can be run so that the relevant values in /proc/fs/ext4/<dev>/mb_stats become non-zero.
> After writing 1 to /sys/fs/ext4/<dev>/mb_stats_clear, those values should return to 0.
> Running another file operation test afterward should make those values increase again.
>
> Best regards,
> Baolin Liu
在 2026/4/14 18:02, Baolin Liu 写道:
> From: Baolin Liu <liubaolin@kylinos.cn>
>
> Add a write-only mb_stats_clear sysfs knob to reset ext4 mballoc
> runtime statistics.This makes it easier to inspect allocator
> activity for a specific workload instead of using counters
> accumulated since mount.
>
> Signed-off-by: Baolin Liu <liubaolin@kylinos.cn>
> ---
> fs/ext4/ext4.h | 1 +
> fs/ext4/mballoc.c | 31 +++++++++++++++++++++++++++++++
> fs/ext4/sysfs.c | 24 ++++++++++++++++++++++++
> 3 files changed, 56 insertions(+)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 7617e2d454ea..3a32e1a515dd 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2995,6 +2995,7 @@ int ext4_fc_record_regions(struct super_block *sb, int ino,
> extern const struct seq_operations ext4_mb_seq_groups_ops;
> extern const struct seq_operations ext4_mb_seq_structs_summary_ops;
> extern int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset);
> +extern void ext4_mb_stats_clear(struct ext4_sb_info *sbi);
> extern int ext4_mb_init(struct super_block *);
> extern void ext4_mb_release(struct super_block *);
> extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index bb58eafb87bc..382c91586b26 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -3219,6 +3219,8 @@ int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
> }
> seq_printf(seq, "\treqs: %u\n", atomic_read(&sbi->s_bal_reqs));
> seq_printf(seq, "\tsuccess: %u\n", atomic_read(&sbi->s_bal_success));
> + seq_printf(seq, "\tblocks_allocated: %u\n",
> + atomic_read(&sbi->s_bal_allocated));
>
> seq_printf(seq, "\tgroups_scanned: %u\n",
> atomic_read(&sbi->s_bal_groups_scanned));
> @@ -4721,6 +4723,35 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
> trace_ext4_mballoc_prealloc(ac);
> }
>
> +void ext4_mb_stats_clear(struct ext4_sb_info *sbi)
> +{
> + int i;
> +
> + atomic_set(&sbi->s_bal_reqs, 0);
> + atomic_set(&sbi->s_bal_success, 0);
> + atomic_set(&sbi->s_bal_allocated, 0);
> + atomic_set(&sbi->s_bal_groups_scanned, 0);
> +
> + for (i = 0; i < EXT4_MB_NUM_CRS; i++) {
> + atomic64_set(&sbi->s_bal_cX_hits[i], 0);
> + atomic64_set(&sbi->s_bal_cX_groups_considered[i], 0);
> + atomic_set(&sbi->s_bal_cX_ex_scanned[i], 0);
> + atomic64_set(&sbi->s_bal_cX_failed[i], 0);
> + }
> +
> + atomic_set(&sbi->s_bal_ex_scanned, 0);
> + atomic_set(&sbi->s_bal_goals, 0);
> + atomic_set(&sbi->s_bal_stream_goals, 0);
> + atomic_set(&sbi->s_bal_len_goals, 0);
> + atomic_set(&sbi->s_bal_2orders, 0);
> + atomic_set(&sbi->s_bal_breaks, 0);
> + atomic_set(&sbi->s_mb_lost_chunks, 0);
> + atomic_set(&sbi->s_mb_buddies_generated, 0);
> + atomic64_set(&sbi->s_mb_generation_time, 0);
> + atomic_set(&sbi->s_mb_preallocated, 0);
> + atomic_set(&sbi->s_mb_discarded, 0);
> +}
> +
> /*
> * Called on failure; free up any blocks from the inode PA for this
> * context. We don't need this for MB_GROUP_PA because we only change
> diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
> index 923b375e017f..a5bd88a99f22 100644
> --- a/fs/ext4/sysfs.c
> +++ b/fs/ext4/sysfs.c
> @@ -41,6 +41,7 @@ typedef enum {
> attr_pointer_atomic,
> attr_journal_task,
> attr_err_report_sec,
> + attr_mb_stats_clear,
> } attr_id_t;
>
> typedef enum {
> @@ -161,6 +162,25 @@ static ssize_t err_report_sec_store(struct ext4_sb_info *sbi,
> return count;
> }
>
> +static ssize_t mb_stats_clear_store(struct ext4_sb_info *sbi,
> + const char *buf, size_t count)
> +{
> + int val;
> + int ret;
> +
> + if (!capable(CAP_SYS_ADMIN))
> + return -EPERM;
> +
> + ret = kstrtoint(skip_spaces(buf), 0, &val);
> + if (ret)
> + return ret;
> + if (val != 1)
> + return -EINVAL;
> +
> + ext4_mb_stats_clear(sbi);
> + return count;
> +}
> +
> static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
> {
> if (!sbi->s_journal)
> @@ -251,6 +271,7 @@ EXT4_ATTR_OFFSET(mb_best_avail_max_trim_order, 0644, mb_order,
> EXT4_ATTR_OFFSET(err_report_sec, 0644, err_report_sec, ext4_sb_info, s_err_report_sec);
> EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
> EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
> +EXT4_ATTR(mb_stats_clear, 0200, mb_stats_clear);
> EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
> EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
> EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
> @@ -301,6 +322,7 @@ static struct attribute *ext4_attrs[] = {
> ATTR_LIST(inode_readahead_blks),
> ATTR_LIST(inode_goal),
> ATTR_LIST(mb_stats),
> + ATTR_LIST(mb_stats_clear),
> ATTR_LIST(mb_max_to_scan),
> ATTR_LIST(mb_min_to_scan),
> ATTR_LIST(mb_order2_req),
> @@ -561,6 +583,8 @@ static ssize_t ext4_attr_store(struct kobject *kobj,
> return trigger_test_error(sbi, buf, len);
> case attr_err_report_sec:
> return err_report_sec_store(sbi, buf, len);
> + case attr_mb_stats_clear:
> + return mb_stats_clear_store(sbi, buf, len);
> default:
> return ext4_generic_attr_store(a, sbi, buf, len);
> }
^ permalink raw reply
* [PATCH v1] ext4: add mb_stats_clear for mballoc statistics
From: Baolin Liu @ 2026-04-14 10:02 UTC (permalink / raw)
To: tytso, adilger.kernel
Cc: liubaolin12138, linux-ext4, linux-kernel, wangguanyu, Baolin Liu
From: Baolin Liu <liubaolin@kylinos.cn>
Add a write-only mb_stats_clear sysfs knob to reset ext4 mballoc
runtime statistics.This makes it easier to inspect allocator
activity for a specific workload instead of using counters
accumulated since mount.
Signed-off-by: Baolin Liu <liubaolin@kylinos.cn>
---
fs/ext4/ext4.h | 1 +
fs/ext4/mballoc.c | 31 +++++++++++++++++++++++++++++++
fs/ext4/sysfs.c | 24 ++++++++++++++++++++++++
3 files changed, 56 insertions(+)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 7617e2d454ea..3a32e1a515dd 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2995,6 +2995,7 @@ int ext4_fc_record_regions(struct super_block *sb, int ino,
extern const struct seq_operations ext4_mb_seq_groups_ops;
extern const struct seq_operations ext4_mb_seq_structs_summary_ops;
extern int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset);
+extern void ext4_mb_stats_clear(struct ext4_sb_info *sbi);
extern int ext4_mb_init(struct super_block *);
extern void ext4_mb_release(struct super_block *);
extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index bb58eafb87bc..382c91586b26 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3219,6 +3219,8 @@ int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
}
seq_printf(seq, "\treqs: %u\n", atomic_read(&sbi->s_bal_reqs));
seq_printf(seq, "\tsuccess: %u\n", atomic_read(&sbi->s_bal_success));
+ seq_printf(seq, "\tblocks_allocated: %u\n",
+ atomic_read(&sbi->s_bal_allocated));
seq_printf(seq, "\tgroups_scanned: %u\n",
atomic_read(&sbi->s_bal_groups_scanned));
@@ -4721,6 +4723,35 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
trace_ext4_mballoc_prealloc(ac);
}
+void ext4_mb_stats_clear(struct ext4_sb_info *sbi)
+{
+ int i;
+
+ atomic_set(&sbi->s_bal_reqs, 0);
+ atomic_set(&sbi->s_bal_success, 0);
+ atomic_set(&sbi->s_bal_allocated, 0);
+ atomic_set(&sbi->s_bal_groups_scanned, 0);
+
+ for (i = 0; i < EXT4_MB_NUM_CRS; i++) {
+ atomic64_set(&sbi->s_bal_cX_hits[i], 0);
+ atomic64_set(&sbi->s_bal_cX_groups_considered[i], 0);
+ atomic_set(&sbi->s_bal_cX_ex_scanned[i], 0);
+ atomic64_set(&sbi->s_bal_cX_failed[i], 0);
+ }
+
+ atomic_set(&sbi->s_bal_ex_scanned, 0);
+ atomic_set(&sbi->s_bal_goals, 0);
+ atomic_set(&sbi->s_bal_stream_goals, 0);
+ atomic_set(&sbi->s_bal_len_goals, 0);
+ atomic_set(&sbi->s_bal_2orders, 0);
+ atomic_set(&sbi->s_bal_breaks, 0);
+ atomic_set(&sbi->s_mb_lost_chunks, 0);
+ atomic_set(&sbi->s_mb_buddies_generated, 0);
+ atomic64_set(&sbi->s_mb_generation_time, 0);
+ atomic_set(&sbi->s_mb_preallocated, 0);
+ atomic_set(&sbi->s_mb_discarded, 0);
+}
+
/*
* Called on failure; free up any blocks from the inode PA for this
* context. We don't need this for MB_GROUP_PA because we only change
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
index 923b375e017f..a5bd88a99f22 100644
--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -41,6 +41,7 @@ typedef enum {
attr_pointer_atomic,
attr_journal_task,
attr_err_report_sec,
+ attr_mb_stats_clear,
} attr_id_t;
typedef enum {
@@ -161,6 +162,25 @@ static ssize_t err_report_sec_store(struct ext4_sb_info *sbi,
return count;
}
+static ssize_t mb_stats_clear_store(struct ext4_sb_info *sbi,
+ const char *buf, size_t count)
+{
+ int val;
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ ret = kstrtoint(skip_spaces(buf), 0, &val);
+ if (ret)
+ return ret;
+ if (val != 1)
+ return -EINVAL;
+
+ ext4_mb_stats_clear(sbi);
+ return count;
+}
+
static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
{
if (!sbi->s_journal)
@@ -251,6 +271,7 @@ EXT4_ATTR_OFFSET(mb_best_avail_max_trim_order, 0644, mb_order,
EXT4_ATTR_OFFSET(err_report_sec, 0644, err_report_sec, ext4_sb_info, s_err_report_sec);
EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
+EXT4_ATTR(mb_stats_clear, 0200, mb_stats_clear);
EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
@@ -301,6 +322,7 @@ static struct attribute *ext4_attrs[] = {
ATTR_LIST(inode_readahead_blks),
ATTR_LIST(inode_goal),
ATTR_LIST(mb_stats),
+ ATTR_LIST(mb_stats_clear),
ATTR_LIST(mb_max_to_scan),
ATTR_LIST(mb_min_to_scan),
ATTR_LIST(mb_order2_req),
@@ -561,6 +583,8 @@ static ssize_t ext4_attr_store(struct kobject *kobj,
return trigger_test_error(sbi, buf, len);
case attr_err_report_sec:
return err_report_sec_store(sbi, buf, len);
+ case attr_mb_stats_clear:
+ return mb_stats_clear_store(sbi, buf, len);
default:
return ext4_generic_attr_store(a, sbi, buf, len);
}
--
2.51.0
^ permalink raw reply related
* Re: [PATCH v7 07/22] iomap: introduce IOMAP_F_FSVERITY and teach writeback to handle fsverity
From: Christoph Hellwig @ 2026-04-14 8:13 UTC (permalink / raw)
To: Andrey Albershteyn
Cc: linux-xfs, fsverity, linux-fsdevel, ebiggers, hch, linux-ext4,
linux-f2fs-devel, linux-btrfs, djwong
In-Reply-To: <20260409131404.1545834-8-aalbersh@kernel.org>
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply
* Re: [PATCH v7 03/22] ovl: use core fsverity ensure info interface
From: Christoph Hellwig @ 2026-04-14 8:13 UTC (permalink / raw)
To: Andrey Albershteyn
Cc: linux-xfs, fsverity, linux-fsdevel, ebiggers, hch, linux-ext4,
linux-f2fs-devel, linux-btrfs, djwong
In-Reply-To: <20260409131404.1545834-4-aalbersh@kernel.org>
On Thu, Apr 09, 2026 at 03:13:35PM +0200, Andrey Albershteyn wrote:
> - if (!fsverity_active(inode) && IS_VERITY(inode)) {
> - /*
> - * If this inode was not yet opened, the verity info hasn't been
> - * loaded yet, so we need to do that here to force it into memory.
> - */
> - filp = kernel_file_open(datapath, O_RDONLY, current_cred());
> - if (IS_ERR(filp))
> - return PTR_ERR(filp);
> - fput(filp);
> - }
> + if (fsverity_active(inode))
> + fsverity_ensure_verity_info(inode);
fsverity_ensure_verity_info already is a no-op for !fsverity_active,
so the check could be remove. Also we should probably propagate the
error return from fsverity_ensure_verity_info here.
^ permalink raw reply
* Re: [PATCH v7 02/22] fsverity: expose ensure_fsverity_info()
From: Christoph Hellwig @ 2026-04-14 8:11 UTC (permalink / raw)
To: Andrey Albershteyn
Cc: linux-xfs, fsverity, linux-fsdevel, ebiggers, hch, linux-ext4,
linux-f2fs-devel, linux-btrfs, djwong
In-Reply-To: <20260409131404.1545834-3-aalbersh@kernel.org>
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply
* Re: [PATCH 4/6] generic/765: Ignore mkfs warning
From: Darrick J. Wong @ 2026-04-13 23:28 UTC (permalink / raw)
To: Theodore Tso
Cc: Ojaswin Mujoo, Zorro Lang, fstests, fdmanana, ritesh.list,
naohiro.aota, wqu, Disha Goel, linux-ext4
In-Reply-To: <20260413204215.GA5461@macsyma-wired.lan>
On Mon, Apr 13, 2026 at 04:42:15PM -0400, Theodore Tso wrote:
> > > > > > The output can get corrupted with warnings like below because clustersize
> > > > > > more than 16xbs is experimental:
> > > > > >
> > > > > > + 16 times the block size is considered experimental
> > > > > >
> > > > > > Hence pipe these to seqres.full to avoid false negatives.
>
> You could also suppress the warnings using the -q option, for example:
>
> mke2fs -Fq -t ext4 -O bigalloc,quota -b 4096 -C 131072 /tmp/foo.img 4G
>
> > > Futher, mke2fs has multiple instances where we print warnings to stderr,
> > > should we go and fix all of them as well?
> >
> > "stderr" meaning "standard error", I'd say that errors are anything that
> > prohibits the format from completing, and only errors should go there.
>
> Sure, I'll accept those changes. But adding -q will allow the test to
> pass using older versions of e2fsprogs, while still allowing stderr to
> go out the expected output.
Aha, maybe that's why I've never run into this when QA'ing fstests.
--D
^ permalink raw reply
* [PATCH] jbd2: enforce power-of-two default revoke hash size at compile time
From: Milos Nikic @ 2026-04-13 21:27 UTC (permalink / raw)
To: jack, tytso, linux-ext4; +Cc: linux-kernel, Milos Nikic
The jbd2 revoke table relies on bitwise AND operations for fast hash
indexing, which requires the hash table size to be a strict power of two.
Currently, this requirement is only enforced at runtime via a J_ASSERT
in jbd2_journal_init_revoke(). While this successfully catches invalid
dynamic allocations, it means a developer accidentally modifying the
hardcoded JOURNAL_REVOKE_DEFAULT_HASH macro will experience a system
panic upon mounting the filesystem during testing.
Add a BUILD_BUG_ON() in journal_init_common() to validate the default
macro at compile time. This acts as an immediate, zero-overhead
safeguard, preventing compilation entirely if the default hash size is
mathematically invalid.
Signed-off-by: Milos Nikic <nikic.milos@gmail.com>
---
fs/jbd2/journal.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 4f397fcdb13c..62b36a2fc4e2 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1565,6 +1565,7 @@ static journal_t *journal_init_common(struct block_device *bdev,
/* The journal is marked for error until we succeed with recovery! */
journal->j_flags = JBD2_ABORT;
+ BUILD_BUG_ON(!is_power_of_2(JOURNAL_REVOKE_DEFAULT_HASH));
/* Set up a default-sized revoke table for the new mount. */
err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
if (err)
--
2.53.0
^ permalink raw reply related
* Re: [PATCH 4/6] generic/765: Ignore mkfs warning
From: Theodore Tso @ 2026-04-13 20:42 UTC (permalink / raw)
To: Darrick J. Wong
Cc: Ojaswin Mujoo, Zorro Lang, fstests, fdmanana, ritesh.list,
naohiro.aota, wqu, Disha Goel, linux-ext4
In-Reply-To: <20260413162120.GV6212@frogsfrogsfrogs>
> > > > > The output can get corrupted with warnings like below because clustersize
> > > > > more than 16xbs is experimental:
> > > > >
> > > > > + 16 times the block size is considered experimental
> > > > >
> > > > > Hence pipe these to seqres.full to avoid false negatives.
You could also suppress the warnings using the -q option, for example:
mke2fs -Fq -t ext4 -O bigalloc,quota -b 4096 -C 131072 /tmp/foo.img 4G
> > Futher, mke2fs has multiple instances where we print warnings to stderr,
> > should we go and fix all of them as well?
>
> "stderr" meaning "standard error", I'd say that errors are anything that
> prohibits the format from completing, and only errors should go there.
Sure, I'll accept those changes. But adding -q will allow the test to
pass using older versions of e2fsprogs, while still allowing stderr to
go out the expected output.
- Ted
^ permalink raw reply
* Re: [patch 15/38] ptp: ptp_vmclock: Replace get_cycles() usage
From: Arnd Bergmann @ 2026-04-13 19:30 UTC (permalink / raw)
To: David Woodhouse, Thomas Gleixner, LKML
Cc: x86, Baolu Lu, iommu, Michael Grzeschik, Netdev, linux-wireless,
Herbert Xu, linux-crypto, Vlastimil Babka (SUSE), linux-mm,
Bernie Thompson, linux-fbdev, Theodore Ts'o, linux-ext4,
Andrew Morton, Uladzislau Rezki (Sony), Marco Elver,
Dmitry Vyukov, kasan-dev, Andrey Ryabinin, Thomas Sailer,
linux-hams, Jason A . Donenfeld, Richard Henderson, linux-alpha,
Russell King, linux-arm-kernel, Catalin Marinas, Huacai Chen,
loongarch, Geert Uytterhoeven, linux-m68k, Dinh Nguyen,
Jonas Bonn, linux-openrisc@vger.kernel.org, Helge Deller,
linux-parisc, Michael Ellerman, linuxppc-dev, Paul Walmsley,
linux-riscv, Heiko Carstens, linux-s390, David S . Miller,
sparclinux
In-Reply-To: <7a48b636cb3146f4f7134c6d4fe42070ac2edb43.camel@infradead.org>
On Mon, Apr 13, 2026, at 17:33, David Woodhouse wrote:
> On Fri, 2026-04-10 at 14:19 +0200, Thomas Gleixner wrote:
>
> ... depend on TSC_RELIABLE¹, since if the guest doesn't believe that it
> is, then the guest shouldn't be trying to use it as the basis for
> precise timing.
>
> ¹ (Or... one of the other zoo of TSC flags for the gradually reducing
> brokenness over the years...)
It looks like this is sufficiently handled in the caller:
static int vmclock_get_crosststamp(struct vmclock_state *st,
struct ptp_system_timestamp *sts,
struct system_counterval_t *system_counter,
struct timespec64 *tspec)
{
....
#ifdef CONFIG_X86
/*
* We'd expect the hypervisor to know this and to report the clock
* status as VMCLOCK_STATUS_UNRELIABLE. But be paranoid.
*/
if (check_tsc_unstable())
return -EINVAL;
#endif
With 486 and ELAN out of the way, Winchip6 seems to be the only
one without X86_FEATURE_TSC, so I think the next logical step would
be to turn off Winchip6 as well and remove all X86_FEATURE_TSC
and CONFIG_X86_TSC checks.
Arnd
^ permalink raw reply
* [PATCH] jbd2: validate transaction state before dropping from journal
From: Milos Nikic @ 2026-04-13 18:08 UTC (permalink / raw)
To: jack, tytso, linux-ext4; +Cc: linux-kernel, Milos Nikic
Currently, __jbd2_journal_drop_transaction() unlinks the transaction
from the journal's checkpoint lists and only then proceeds to validate the
transaction's internal state using a series of J_ASSERTs.
There is no need to 'mutate before validate'. If we are going to halt the
system that makes manipulating corrupted pointers in memory irrelevant.
Move the state validation block above the pointer manipulation. This
ensures the transaction is entirely valid before modifying the journal's
internal lists, modernizing the function's logic and paving the way
for future graceful degradation of these assertions.
Signed-off-by: Milos Nikic <nikic.milos@gmail.com>
---
fs/jbd2/checkpoint.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 1508e2f54462..c82b6bedd27b 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -703,6 +703,15 @@ void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transact
{
assert_spin_locked(&journal->j_list_lock);
+ J_ASSERT(transaction->t_state == T_FINISHED);
+ J_ASSERT(transaction->t_buffers == NULL);
+ J_ASSERT(transaction->t_forget == NULL);
+ J_ASSERT(transaction->t_shadow_list == NULL);
+ J_ASSERT(transaction->t_checkpoint_list == NULL);
+ J_ASSERT(atomic_read(&transaction->t_updates) == 0);
+ J_ASSERT(journal->j_committing_transaction != transaction);
+ J_ASSERT(journal->j_running_transaction != transaction);
+
journal->j_shrink_transaction = NULL;
if (transaction->t_cpnext) {
transaction->t_cpnext->t_cpprev = transaction->t_cpprev;
@@ -714,15 +723,6 @@ void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transact
journal->j_checkpoint_transactions = NULL;
}
- J_ASSERT(transaction->t_state == T_FINISHED);
- J_ASSERT(transaction->t_buffers == NULL);
- J_ASSERT(transaction->t_forget == NULL);
- J_ASSERT(transaction->t_shadow_list == NULL);
- J_ASSERT(transaction->t_checkpoint_list == NULL);
- J_ASSERT(atomic_read(&transaction->t_updates) == 0);
- J_ASSERT(journal->j_committing_transaction != transaction);
- J_ASSERT(journal->j_running_transaction != transaction);
-
trace_jbd2_drop_transaction(journal, transaction);
jbd2_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);
--
2.53.0
^ permalink raw reply related
* Re: [PATCH 4/6] generic/765: Ignore mkfs warning
From: Darrick J. Wong @ 2026-04-13 16:21 UTC (permalink / raw)
To: Ojaswin Mujoo
Cc: Zorro Lang, fstests, fdmanana, ritesh.list, naohiro.aota, wqu,
Disha Goel, linux-ext4, Theodore Ts'o
In-Reply-To: <adyxi7156VAbL-G1@li-dc0c254c-257c-11b2-a85c-98b6c1322444.ibm.com>
On Mon, Apr 13, 2026 at 02:34:11PM +0530, Ojaswin Mujoo wrote:
> On Sun, Apr 12, 2026 at 10:38:18PM +0530, Ojaswin Mujoo wrote:
> > On Fri, Apr 10, 2026 at 09:54:35AM -0700, Darrick J. Wong wrote:
> > > On Fri, Apr 10, 2026 at 12:06:04PM +0530, Ojaswin Mujoo wrote:
> > > > This test validates atomic writes for all possible block sizes. In ext4, for
> > > > smaller block sizes with configurations like:
> > > >
> > > > export MKFS_OPTIONS="-O bigalloc,quota -b 65536 -C 131072"
> > > >
> > > > The output can get corrupted with warnings like below because clustersize
> > > > more than 16xbs is experimental:
> > > >
> > > > + 16 times the block size is considered experimental
> > > >
> > > > Hence pipe these to seqres.full to avoid false negatives.
> > > >
> > > > Reported-by: Disha Goel <disgoel@linux.ibm.com>
> > > > Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
> > >
> > > Seems fine, though I think I'd rather mke2fs get patched to fix this.
> > >
> > > I'd let the maintainer decide if he wants this, but ... I'm not sure if
> > > he's actually going to receive this message. :/
> >
> > Hi Darrick, yes I'm preparing a quick patch for this. We might still
> > need this so people on older distro who wont have the e2fsprogs fix dont
> > see the failure.
>
> Hi Darrick,
>
> Looking at it again, I am just wondering if its really an issue that
> mke2fs is printing this warning to stderr. Isn't stderr the right place
> for errors and warning (even non critical ones)?
>
> Futher, mke2fs has multiple instances where we print warnings to stderr,
> should we go and fix all of them as well?
"stderr" meaning "standard error", I'd say that errors are anything that
prohibits the format from completing, and only errors should go there.
We ought to kick this to the ext4 list though...
--D
> Regards,
> ojaswin
>
> >
> > Regards,
> > ojaswin
> >
> > >
> > > --D
> > >
> > > > ---
> > > > tests/generic/765 | 3 ++-
> > > > 1 file changed, 2 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/tests/generic/765 b/tests/generic/765
> > > > index 09be53db..b7cc70f1 100755
> > > > --- a/tests/generic/765
> > > > +++ b/tests/generic/765
> > > > @@ -64,7 +64,8 @@ test_atomic_writes()
> > > > local bsize=$1
> > > >
> > > > get_mkfs_opts $bsize
> > > > - _scratch_mkfs $mkfs_opts >> $seqres.full
> > > > + _scratch_mkfs $mkfs_opts &>> $seqres.full || \
> > > > + echo "mkfs $mkfs_opts failed"
> > > > _scratch_mount
> > > >
> > > > test "$FSTYP" = "xfs" && _xfs_force_bdev data $SCRATCH_MNT
> > > > --
> > > > 2.53.0
> > > >
> > > >
>
^ permalink raw reply
* Re: [patch 15/38] ptp: ptp_vmclock: Replace get_cycles() usage
From: David Woodhouse @ 2026-04-13 15:33 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: Arnd Bergmann, x86, Lu Baolu, iommu, Michael Grzeschik, netdev,
linux-wireless, Herbert Xu, linux-crypto, Vlastimil Babka,
linux-mm, Bernie Thompson, linux-fbdev, Theodore Tso, linux-ext4,
Andrew Morton, Uladzislau Rezki, Marco Elver, Dmitry Vyukov,
kasan-dev, Andrey Ryabinin, Thomas Sailer, linux-hams,
Jason A. Donenfeld, Richard Henderson, linux-alpha, Russell King,
linux-arm-kernel, Catalin Marinas, Huacai Chen, loongarch,
Geert Uytterhoeven, linux-m68k, Dinh Nguyen, Jonas Bonn,
linux-openrisc, Helge Deller, linux-parisc, Michael Ellerman,
linuxppc-dev, Paul Walmsley, linux-riscv, Heiko Carstens,
linux-s390, David S. Miller, sparclinux
In-Reply-To: <20260410120318.592237447@kernel.org>
[-- Attachment #1: Type: text/plain, Size: 994 bytes --]
On Fri, 2026-04-10 at 14:19 +0200, Thomas Gleixner wrote:
> get_cycles() is not really well defined and similar to other usaage of the
> underlying hardware CPU counters the PTP vmclock should use an explicit
> interface as well.
>
> Implement ptp_vmclock_read_cpu_counter() in arm64 and x86 and simplify the
> Kconfig selection while at it.
>
> No functional change.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Although I might follow up with a change to make this...
> +static inline u64 ptp_vmclock_read_cpu_counter(void)
> +{
> + return cpu_feature_enabled(X86_FEATURE_TSC) ? rdtsc() : 0;
> +}
> +
... depend on TSC_RELIABLE¹, since if the guest doesn't believe that it
is, then the guest shouldn't be trying to use it as the basis for
precise timing.
¹ (Or... one of the other zoo of TSC flags for the gradually reducing
brokenness over the years...)
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^ permalink raw reply
* Re: [patch 10/38] arcnet: Remove function timing code
From: David Woodhouse @ 2026-04-13 15:29 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: Michael Grzeschik, netdev, Arnd Bergmann, x86, Lu Baolu, iommu,
linux-wireless, Herbert Xu, linux-crypto, Vlastimil Babka,
linux-mm, Bernie Thompson, linux-fbdev, Theodore Tso, linux-ext4,
Andrew Morton, Uladzislau Rezki, Marco Elver, Dmitry Vyukov,
kasan-dev, Andrey Ryabinin, Thomas Sailer, linux-hams,
Jason A. Donenfeld, Richard Henderson, linux-alpha, Russell King,
linux-arm-kernel, Catalin Marinas, Huacai Chen, loongarch,
Geert Uytterhoeven, linux-m68k, Dinh Nguyen, Jonas Bonn,
linux-openrisc, Helge Deller, linux-parisc, Michael Ellerman,
linuxppc-dev, Paul Walmsley, linux-riscv, Heiko Carstens,
linux-s390, David S. Miller, sparclinux
In-Reply-To: <20260410120318.253872322@kernel.org>
[-- Attachment #1: Type: text/plain, Size: 778 bytes --]
On Fri, 2026-04-10 at 14:19 +0200, Thomas Gleixner wrote:
> ARCNET is a museums piece and the function timing can be done with
> ftrace. Remove the cruft.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: Michael Grzeschik <m.grzeschik@pengutronix.de>
> Cc: netdev@vger.kernel.org
> ---
> drivers/net/arcnet/arc-rimi.c | 4 ++--
> drivers/net/arcnet/arcdevice.h | 20 +-------------------
> drivers/net/arcnet/com20020.c | 6 ++----
> drivers/net/arcnet/com90io.c | 6 ++----
> drivers/net/arcnet/com90xx.c | 4 ++--
> 5 files changed, 9 insertions(+), 31 deletions(-)
Acked-by: David Woodhouse <dwmw2@infradead.org>
By coincidence, I took the last of my ARCNET cards to the tip just this
morning...
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^ permalink raw reply
* Re: [patch 17/38] ext4: Replace get_cycles() usage with ktime_get()
From: Arnd Bergmann @ 2026-04-13 14:46 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: Theodore Ts'o, linux-ext4, x86, Baolu Lu, iommu,
Michael Grzeschik, Netdev, linux-wireless, Herbert Xu,
linux-crypto, Vlastimil Babka (SUSE), linux-mm, David Woodhouse,
Bernie Thompson, linux-fbdev, Andrew Morton,
Uladzislau Rezki (Sony), Marco Elver, Dmitry Vyukov, kasan-dev,
Andrey Ryabinin, Thomas Sailer, linux-hams, Jason A . Donenfeld,
Richard Henderson, linux-alpha, Russell King, linux-arm-kernel,
Catalin Marinas, Huacai Chen, loongarch, Geert Uytterhoeven,
linux-m68k, Dinh Nguyen, Jonas Bonn,
linux-openrisc@vger.kernel.org, Helge Deller, linux-parisc,
Michael Ellerman, linuxppc-dev, Paul Walmsley, linux-riscv,
Heiko Carstens, linux-s390, David S . Miller, sparclinux
In-Reply-To: <20260410120318.727211419@kernel.org>
On Fri, Apr 10, 2026, at 14:19, Thomas Gleixner wrote:
> get_cycles() is not guaranteed to be functional on all systems/platforms
> and the values returned are unitless and not easy to map to something
> useful.
>
> Use ktime_get() instead, which provides nanosecond timestamps and is
> functional everywhere.
>
> This is part of a larger effort to limit get_cycles() usage to low level
> architecture code.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: "Theodore Ts'o" <tytso@mit.edu>
> Cc: linux-ext4@vger.kernel.org
I think this is technically an ABI chance, since the time
difference gets exported through procfs, but the new version
is clearly the right thing to do since it replaces a hardware
specific value with a portable one.
Arnd
^ permalink raw reply
* Re: [patch 38/38] treewide: Remove asm/timex.h includes from generic code
From: Arnd Bergmann @ 2026-04-13 14:45 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: x86, Baolu Lu, iommu, Michael Grzeschik, Netdev, linux-wireless,
Herbert Xu, linux-crypto, Vlastimil Babka (SUSE), linux-mm,
David Woodhouse, Bernie Thompson, linux-fbdev, Theodore Ts'o,
linux-ext4, Andrew Morton, Uladzislau Rezki (Sony), Marco Elver,
Dmitry Vyukov, kasan-dev, Andrey Ryabinin, Thomas Sailer,
linux-hams, Jason A . Donenfeld, Richard Henderson, linux-alpha,
Russell King, linux-arm-kernel, Catalin Marinas, Huacai Chen,
loongarch, Geert Uytterhoeven, linux-m68k, Dinh Nguyen,
Jonas Bonn, linux-openrisc@vger.kernel.org, Helge Deller,
linux-parisc, Michael Ellerman, linuxppc-dev, Paul Walmsley,
linux-riscv, Heiko Carstens, linux-s390, David S . Miller,
sparclinux
In-Reply-To: <20260410120320.163559629@kernel.org>
On Fri, Apr 10, 2026, at 14:21, Thomas Gleixner wrote:
> asm/timex.h does not provide any functionality for non-architecture code
> anymore.
>
> Remove the asm-generic fallback and all references in include and source
> files along with the random_get_entropy() #ifdeffery in timex.h.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> ---
> include/asm-generic/Kbuild | 1 -
> include/asm-generic/timex.h | 15 ---------------
> include/linux/random.h | 3 +++
> include/linux/timex.h | 26 --------------------------
Acked-by: Arnd Bergmann <arnd@arndb.de>
^ permalink raw reply
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