December 2017 - Linux-stable-mirror

[Linux-stable-mirror] Patch "drm/fsl-dcu: avoid disabling pixel clock twice on suspend" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled drm/fsl-dcu: avoid disabling pixel clock twice on suspend to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: drm-fsl-dcu-avoid-disabling-pixel-clock-twice-on-suspend.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 9306e996574f7f57136a62e49cd0075f85713623 Mon Sep 17 00:00:00 2001 From: Stefan Agner <stefan(a)agner.ch> Date: Thu, 9 Nov 2017 15:39:56 +0100 Subject: drm/fsl-dcu: avoid disabling pixel clock twice on suspend From: Stefan Agner <stefan(a)agner.ch> commit 9306e996574f7f57136a62e49cd0075f85713623 upstream. With commit 0a70c998d0c5 ("drm/fsl-dcu: enable pixel clock when enabling CRTC") the pixel clock is controlled by the CRTC code. Disabling the pixel clock in suspend leads to a warning due to the second clk_disable_unprepare call: WARNING: CPU: 0 PID: 359 at drivers/clk/clk.c:594 clk_core_disable+0x8c/0x90 Remove clk_disable_unprepare call for pixel clock to avoid unbalanced clock disable on suspend. Fixes: 0a70c998d0c5 ("drm/fsl-dcu: enable pixel clock when enabling CRTC") Signed-off-by: Stefan Agner <stefan(a)agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 1 - 1 file changed, 1 deletion(-) --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c @@ -210,7 +210,6 @@ static int fsl_dcu_drm_pm_suspend(struct return PTR_ERR(fsl_dev->state); } - clk_disable_unprepare(fsl_dev->pix_clk); clk_disable_unprepare(fsl_dev->clk); return 0; Patches currently in stable-queue which might be from stefan(a)agner.ch are queue-4.14/drm-fsl-dcu-avoid-disabling-pixel-clock-twice-on-suspend.patch queue-4.14/drm-fsl-dcu-enable-irq-before-drm_atomic_helper_resume.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "drm/fsl-dcu: enable IRQ before drm_atomic_helper_resume()" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled drm/fsl-dcu: enable IRQ before drm_atomic_helper_resume() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: drm-fsl-dcu-enable-irq-before-drm_atomic_helper_resume.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 9fd99f4f3f5e13ce959900ae57d64b1bdb51d823 Mon Sep 17 00:00:00 2001 From: Stefan Agner <stefan(a)agner.ch> Date: Fri, 10 Nov 2017 10:15:28 +0100 Subject: drm/fsl-dcu: enable IRQ before drm_atomic_helper_resume() From: Stefan Agner <stefan(a)agner.ch> commit 9fd99f4f3f5e13ce959900ae57d64b1bdb51d823 upstream. The resume helpers wait for a vblank to occurre hence IRQ need to be enabled. This avoids a warning as follows during resume: WARNING: CPU: 0 PID: 314 at drivers/gpu/drm/drm_atomic_helper.c:1249 drm_atomic_helper_wait_for_vblanks.part.1+0x284/0x288 [CRTC:28:crtc-0] vblank wait timed out Signed-off-by: Stefan Agner <stefan(a)agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c @@ -265,6 +265,7 @@ static int fsl_dcu_drm_pm_resume(struct if (fsl_dev->tcon) fsl_tcon_bypass_enable(fsl_dev->tcon); fsl_dcu_drm_init_planes(fsl_dev->drm); + enable_irq(fsl_dev->irq); drm_atomic_helper_resume(fsl_dev->drm, fsl_dev->state); console_lock(); @@ -272,7 +273,6 @@ static int fsl_dcu_drm_pm_resume(struct console_unlock(); drm_kms_helper_poll_enable(fsl_dev->drm); - enable_irq(fsl_dev->irq); return 0; } Patches currently in stable-queue which might be from stefan(a)agner.ch are queue-4.9/drm-fsl-dcu-avoid-disabling-pixel-clock-twice-on-suspend.patch queue-4.9/drm-fsl-dcu-enable-irq-before-drm_atomic_helper_resume.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "drm/fsl-dcu: avoid disabling pixel clock twice on suspend" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled drm/fsl-dcu: avoid disabling pixel clock twice on suspend to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: drm-fsl-dcu-avoid-disabling-pixel-clock-twice-on-suspend.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 9306e996574f7f57136a62e49cd0075f85713623 Mon Sep 17 00:00:00 2001 From: Stefan Agner <stefan(a)agner.ch> Date: Thu, 9 Nov 2017 15:39:56 +0100 Subject: drm/fsl-dcu: avoid disabling pixel clock twice on suspend From: Stefan Agner <stefan(a)agner.ch> commit 9306e996574f7f57136a62e49cd0075f85713623 upstream. With commit 0a70c998d0c5 ("drm/fsl-dcu: enable pixel clock when enabling CRTC") the pixel clock is controlled by the CRTC code. Disabling the pixel clock in suspend leads to a warning due to the second clk_disable_unprepare call: WARNING: CPU: 0 PID: 359 at drivers/clk/clk.c:594 clk_core_disable+0x8c/0x90 Remove clk_disable_unprepare call for pixel clock to avoid unbalanced clock disable on suspend. Fixes: 0a70c998d0c5 ("drm/fsl-dcu: enable pixel clock when enabling CRTC") Signed-off-by: Stefan Agner <stefan(a)agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 1 - 1 file changed, 1 deletion(-) --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c @@ -243,7 +243,6 @@ static int fsl_dcu_drm_pm_suspend(struct return PTR_ERR(fsl_dev->state); } - clk_disable_unprepare(fsl_dev->pix_clk); clk_disable_unprepare(fsl_dev->clk); return 0; Patches currently in stable-queue which might be from stefan(a)agner.ch are queue-4.9/drm-fsl-dcu-avoid-disabling-pixel-clock-twice-on-suspend.patch queue-4.9/drm-fsl-dcu-enable-irq-before-drm_atomic_helper_resume.patch

7 years, 4 months

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[Linux-stable-mirror] drm/fsl-dcu: fixes for stable v4.14

by Stefan Agner

Hi, The following two fixes make sure that suspend/resume works again for the Freescale DCU driver: 9306e996574f ("drm/fsl-dcu: avoid disabling pixel clock twice on suspend") 9fd99f4f3f5e ("drm/fsl-dcu: enable IRQ before drm_atomic_helper_resume()") It would be good if they make it into v4.14 sometime. -- Stefan

7 years, 4 months

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[Linux-stable-mirror] Patch "bcache: recover data from backing when data is clean" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bcache: recover data from backing when data is clean to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bcache-recover-data-from-backing-when-data-is-clean.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From e393aa2446150536929140739f09c6ecbcbea7f0 Mon Sep 17 00:00:00 2001 From: Rui Hua <huarui.dev(a)gmail.com> Date: Fri, 24 Nov 2017 15:14:26 -0800 Subject: bcache: recover data from backing when data is clean From: Rui Hua <huarui.dev(a)gmail.com> commit e393aa2446150536929140739f09c6ecbcbea7f0 upstream. When we send a read request and hit the clean data in cache device, there is a situation called cache read race in bcache(see the commit in the tail of cache_look_up(), the following explaination just copy from there): The bucket we're reading from might be reused while our bio is in flight, and we could then end up reading the wrong data. We guard against this by checking (in bch_cache_read_endio()) if the pointer is stale again; if so, we treat it as an error (s->iop.error = -EINTR) and reread from the backing device (but we don't pass that error up anywhere) It should be noted that cache read race happened under normal circumstances, not the circumstance when SSD failed, it was counted and shown in /sys/fs/bcache/XXX/internal/cache_read_races. Without this patch, when we use writeback mode, we will never reread from the backing device when cache read race happened, until the whole cache device is clean, because the condition (s->recoverable && (dc && !atomic_read(&dc->has_dirty))) is false in cached_dev_read_error(). In this situation, the s->iop.error(= -EINTR) will be passed up, at last, user will receive -EINTR when it's bio end, this is not suitable, and wield to up-application. In this patch, we use s->read_dirty_data to judge whether the read request hit dirty data in cache device, it is safe to reread data from the backing device when the read request hit clean data. This can not only handle cache read race, but also recover data when failed read request from cache device. [edited by mlyle to fix up whitespace, commit log title, comment spelling] Fixes: d59b23795933 ("bcache: only permit to recovery read error when cache device is clean") Signed-off-by: Hua Rui <huarui.dev(a)gmail.com> Reviewed-by: Michael Lyle <mlyle(a)lyle.org> Reviewed-by: Coly Li <colyli(a)suse.de> Signed-off-by: Michael Lyle <mlyle(a)lyle.org> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/md/bcache/request.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -702,16 +702,15 @@ static void cached_dev_read_error(struct { struct search *s = container_of(cl, struct search, cl); struct bio *bio = &s->bio.bio; - struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); /* - * If cache device is dirty (dc->has_dirty is non-zero), then - * recovery a failed read request from cached device may get a - * stale data back. So read failure recovery is only permitted - * when cache device is clean. + * If read request hit dirty data (s->read_dirty_data is true), + * then recovery a failed read request from cached device may + * get a stale data back. So read failure recovery is only + * permitted when read request hit clean data in cache device, + * or when cache read race happened. */ - if (s->recoverable && - (dc && !atomic_read(&dc->has_dirty))) { + if (s->recoverable && !s->read_dirty_data) { /* Retry from the backing device: */ trace_bcache_read_retry(s->orig_bio); Patches currently in stable-queue which might be from huarui.dev(a)gmail.com are queue-4.9/bcache-recover-data-from-backing-when-data-is-clean.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "bcache: only permit to recovery read error when cache device is clean" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bcache: only permit to recovery read error when cache device is clean to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bcache-only-permit-to-recovery-read-error-when-cache-device-is-clean.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From d59b23795933678c9638fd20c942d2b4f3cd6185 Mon Sep 17 00:00:00 2001 From: Coly Li <colyli(a)suse.de> Date: Mon, 30 Oct 2017 14:46:31 -0700 Subject: bcache: only permit to recovery read error when cache device is clean From: Coly Li <colyli(a)suse.de> commit d59b23795933678c9638fd20c942d2b4f3cd6185 upstream. When bcache does read I/Os, for example in writeback or writethrough mode, if a read request on cache device is failed, bcache will try to recovery the request by reading from cached device. If the data on cached device is not synced with cache device, then requester will get a stale data. For critical storage system like database, providing stale data from recovery may result an application level data corruption, which is unacceptible. With this patch, for a failed read request in writeback or writethrough mode, recovery a recoverable read request only happens when cache device is clean. That is to say, all data on cached device is up to update. For other cache modes in bcache, read request will never hit cached_dev_read_error(), they don't need this patch. Please note, because cache mode can be switched arbitrarily in run time, a writethrough mode might be switched from a writeback mode. Therefore checking dc->has_data in writethrough mode still makes sense. Changelog: V4: Fix parens error pointed by Michael Lyle. v3: By response from Kent Oversteet, he thinks recovering stale data is a bug to fix, and option to permit it is unnecessary. So this version the sysfs file is removed. v2: rename sysfs entry from allow_stale_data_on_failure to allow_stale_data_on_failure, and fix the confusing commit log. v1: initial patch posted. [small change to patch comment spelling by mlyle] Signed-off-by: Coly Li <colyli(a)suse.de> Signed-off-by: Michael Lyle <mlyle(a)lyle.org> Reported-by: Arne Wolf <awolf(a)lenovo.com> Reviewed-by: Michael Lyle <mlyle(a)lyle.org> Cc: Kent Overstreet <kent.overstreet(a)gmail.com> Cc: Nix <nix(a)esperi.org.uk> Cc: Kai Krakow <hurikhan77(a)gmail.com> Cc: Eric Wheeler <bcache(a)lists.ewheeler.net> Cc: Junhui Tang <tang.junhui(a)zte.com.cn> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/md/bcache/request.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -702,8 +702,16 @@ static void cached_dev_read_error(struct { struct search *s = container_of(cl, struct search, cl); struct bio *bio = &s->bio.bio; + struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); - if (s->recoverable) { + /* + * If cache device is dirty (dc->has_dirty is non-zero), then + * recovery a failed read request from cached device may get a + * stale data back. So read failure recovery is only permitted + * when cache device is clean. + */ + if (s->recoverable && + (dc && !atomic_read(&dc->has_dirty))) { /* Retry from the backing device: */ trace_bcache_read_retry(s->orig_bio); Patches currently in stable-queue which might be from colyli(a)suse.de are queue-4.9/bcache-only-permit-to-recovery-read-error-when-cache-device-is-clean.patch queue-4.9/bcache-recover-data-from-backing-when-data-is-clean.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "bcache: recover data from backing when data is clean" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bcache: recover data from backing when data is clean to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bcache-recover-data-from-backing-when-data-is-clean.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From e393aa2446150536929140739f09c6ecbcbea7f0 Mon Sep 17 00:00:00 2001 From: Rui Hua <huarui.dev(a)gmail.com> Date: Fri, 24 Nov 2017 15:14:26 -0800 Subject: bcache: recover data from backing when data is clean From: Rui Hua <huarui.dev(a)gmail.com> commit e393aa2446150536929140739f09c6ecbcbea7f0 upstream. When we send a read request and hit the clean data in cache device, there is a situation called cache read race in bcache(see the commit in the tail of cache_look_up(), the following explaination just copy from there): The bucket we're reading from might be reused while our bio is in flight, and we could then end up reading the wrong data. We guard against this by checking (in bch_cache_read_endio()) if the pointer is stale again; if so, we treat it as an error (s->iop.error = -EINTR) and reread from the backing device (but we don't pass that error up anywhere) It should be noted that cache read race happened under normal circumstances, not the circumstance when SSD failed, it was counted and shown in /sys/fs/bcache/XXX/internal/cache_read_races. Without this patch, when we use writeback mode, we will never reread from the backing device when cache read race happened, until the whole cache device is clean, because the condition (s->recoverable && (dc && !atomic_read(&dc->has_dirty))) is false in cached_dev_read_error(). In this situation, the s->iop.error(= -EINTR) will be passed up, at last, user will receive -EINTR when it's bio end, this is not suitable, and wield to up-application. In this patch, we use s->read_dirty_data to judge whether the read request hit dirty data in cache device, it is safe to reread data from the backing device when the read request hit clean data. This can not only handle cache read race, but also recover data when failed read request from cache device. [edited by mlyle to fix up whitespace, commit log title, comment spelling] Fixes: d59b23795933 ("bcache: only permit to recovery read error when cache device is clean") Signed-off-by: Hua Rui <huarui.dev(a)gmail.com> Reviewed-by: Michael Lyle <mlyle(a)lyle.org> Reviewed-by: Coly Li <colyli(a)suse.de> Signed-off-by: Michael Lyle <mlyle(a)lyle.org> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/md/bcache/request.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -707,16 +707,15 @@ static void cached_dev_read_error(struct { struct search *s = container_of(cl, struct search, cl); struct bio *bio = &s->bio.bio; - struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); /* - * If cache device is dirty (dc->has_dirty is non-zero), then - * recovery a failed read request from cached device may get a - * stale data back. So read failure recovery is only permitted - * when cache device is clean. + * If read request hit dirty data (s->read_dirty_data is true), + * then recovery a failed read request from cached device may + * get a stale data back. So read failure recovery is only + * permitted when read request hit clean data in cache device, + * or when cache read race happened. */ - if (s->recoverable && - (dc && !atomic_read(&dc->has_dirty))) { + if (s->recoverable && !s->read_dirty_data) { /* Retry from the backing device: */ trace_bcache_read_retry(s->orig_bio); Patches currently in stable-queue which might be from huarui.dev(a)gmail.com are queue-4.4/bcache-recover-data-from-backing-when-data-is-clean.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "bcache: only permit to recovery read error when cache device is clean" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bcache: only permit to recovery read error when cache device is clean to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bcache-only-permit-to-recovery-read-error-when-cache-device-is-clean.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From d59b23795933678c9638fd20c942d2b4f3cd6185 Mon Sep 17 00:00:00 2001 From: Coly Li <colyli(a)suse.de> Date: Mon, 30 Oct 2017 14:46:31 -0700 Subject: bcache: only permit to recovery read error when cache device is clean From: Coly Li <colyli(a)suse.de> commit d59b23795933678c9638fd20c942d2b4f3cd6185 upstream. When bcache does read I/Os, for example in writeback or writethrough mode, if a read request on cache device is failed, bcache will try to recovery the request by reading from cached device. If the data on cached device is not synced with cache device, then requester will get a stale data. For critical storage system like database, providing stale data from recovery may result an application level data corruption, which is unacceptible. With this patch, for a failed read request in writeback or writethrough mode, recovery a recoverable read request only happens when cache device is clean. That is to say, all data on cached device is up to update. For other cache modes in bcache, read request will never hit cached_dev_read_error(), they don't need this patch. Please note, because cache mode can be switched arbitrarily in run time, a writethrough mode might be switched from a writeback mode. Therefore checking dc->has_data in writethrough mode still makes sense. Changelog: V4: Fix parens error pointed by Michael Lyle. v3: By response from Kent Oversteet, he thinks recovering stale data is a bug to fix, and option to permit it is unnecessary. So this version the sysfs file is removed. v2: rename sysfs entry from allow_stale_data_on_failure to allow_stale_data_on_failure, and fix the confusing commit log. v1: initial patch posted. [small change to patch comment spelling by mlyle] Signed-off-by: Coly Li <colyli(a)suse.de> Signed-off-by: Michael Lyle <mlyle(a)lyle.org> Reported-by: Arne Wolf <awolf(a)lenovo.com> Reviewed-by: Michael Lyle <mlyle(a)lyle.org> Cc: Kent Overstreet <kent.overstreet(a)gmail.com> Cc: Nix <nix(a)esperi.org.uk> Cc: Kai Krakow <hurikhan77(a)gmail.com> Cc: Eric Wheeler <bcache(a)lists.ewheeler.net> Cc: Junhui Tang <tang.junhui(a)zte.com.cn> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/md/bcache/request.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -707,8 +707,16 @@ static void cached_dev_read_error(struct { struct search *s = container_of(cl, struct search, cl); struct bio *bio = &s->bio.bio; + struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); - if (s->recoverable) { + /* + * If cache device is dirty (dc->has_dirty is non-zero), then + * recovery a failed read request from cached device may get a + * stale data back. So read failure recovery is only permitted + * when cache device is clean. + */ + if (s->recoverable && + (dc && !atomic_read(&dc->has_dirty))) { /* Retry from the backing device: */ trace_bcache_read_retry(s->orig_bio); Patches currently in stable-queue which might be from colyli(a)suse.de are queue-4.4/bcache-only-permit-to-recovery-read-error-when-cache-device-is-clean.patch queue-4.4/bcache-recover-data-from-backing-when-data-is-clean.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "bcache: recover data from backing when data is clean" has been added to the 3.18-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bcache: recover data from backing when data is clean to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bcache-recover-data-from-backing-when-data-is-clean.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From e393aa2446150536929140739f09c6ecbcbea7f0 Mon Sep 17 00:00:00 2001 From: Rui Hua <huarui.dev(a)gmail.com> Date: Fri, 24 Nov 2017 15:14:26 -0800 Subject: bcache: recover data from backing when data is clean From: Rui Hua <huarui.dev(a)gmail.com> commit e393aa2446150536929140739f09c6ecbcbea7f0 upstream. When we send a read request and hit the clean data in cache device, there is a situation called cache read race in bcache(see the commit in the tail of cache_look_up(), the following explaination just copy from there): The bucket we're reading from might be reused while our bio is in flight, and we could then end up reading the wrong data. We guard against this by checking (in bch_cache_read_endio()) if the pointer is stale again; if so, we treat it as an error (s->iop.error = -EINTR) and reread from the backing device (but we don't pass that error up anywhere) It should be noted that cache read race happened under normal circumstances, not the circumstance when SSD failed, it was counted and shown in /sys/fs/bcache/XXX/internal/cache_read_races. Without this patch, when we use writeback mode, we will never reread from the backing device when cache read race happened, until the whole cache device is clean, because the condition (s->recoverable && (dc && !atomic_read(&dc->has_dirty))) is false in cached_dev_read_error(). In this situation, the s->iop.error(= -EINTR) will be passed up, at last, user will receive -EINTR when it's bio end, this is not suitable, and wield to up-application. In this patch, we use s->read_dirty_data to judge whether the read request hit dirty data in cache device, it is safe to reread data from the backing device when the read request hit clean data. This can not only handle cache read race, but also recover data when failed read request from cache device. [edited by mlyle to fix up whitespace, commit log title, comment spelling] Fixes: d59b23795933 ("bcache: only permit to recovery read error when cache device is clean") Signed-off-by: Hua Rui <huarui.dev(a)gmail.com> Reviewed-by: Michael Lyle <mlyle(a)lyle.org> Reviewed-by: Coly Li <colyli(a)suse.de> Signed-off-by: Michael Lyle <mlyle(a)lyle.org> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/md/bcache/request.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -705,16 +705,15 @@ static void cached_dev_read_error(struct { struct search *s = container_of(cl, struct search, cl); struct bio *bio = &s->bio.bio; - struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); /* - * If cache device is dirty (dc->has_dirty is non-zero), then - * recovery a failed read request from cached device may get a - * stale data back. So read failure recovery is only permitted - * when cache device is clean. + * If read request hit dirty data (s->read_dirty_data is true), + * then recovery a failed read request from cached device may + * get a stale data back. So read failure recovery is only + * permitted when read request hit clean data in cache device, + * or when cache read race happened. */ - if (s->recoverable && - (dc && !atomic_read(&dc->has_dirty))) { + if (s->recoverable && !s->read_dirty_data) { /* Retry from the backing device: */ trace_bcache_read_retry(s->orig_bio); Patches currently in stable-queue which might be from huarui.dev(a)gmail.com are queue-3.18/bcache-recover-data-from-backing-when-data-is-clean.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "bcache: only permit to recovery read error when cache device is clean" has been added to the 3.18-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bcache: only permit to recovery read error when cache device is clean to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bcache-only-permit-to-recovery-read-error-when-cache-device-is-clean.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From d59b23795933678c9638fd20c942d2b4f3cd6185 Mon Sep 17 00:00:00 2001 From: Coly Li <colyli(a)suse.de> Date: Mon, 30 Oct 2017 14:46:31 -0700 Subject: bcache: only permit to recovery read error when cache device is clean From: Coly Li <colyli(a)suse.de> commit d59b23795933678c9638fd20c942d2b4f3cd6185 upstream. When bcache does read I/Os, for example in writeback or writethrough mode, if a read request on cache device is failed, bcache will try to recovery the request by reading from cached device. If the data on cached device is not synced with cache device, then requester will get a stale data. For critical storage system like database, providing stale data from recovery may result an application level data corruption, which is unacceptible. With this patch, for a failed read request in writeback or writethrough mode, recovery a recoverable read request only happens when cache device is clean. That is to say, all data on cached device is up to update. For other cache modes in bcache, read request will never hit cached_dev_read_error(), they don't need this patch. Please note, because cache mode can be switched arbitrarily in run time, a writethrough mode might be switched from a writeback mode. Therefore checking dc->has_data in writethrough mode still makes sense. Changelog: V4: Fix parens error pointed by Michael Lyle. v3: By response from Kent Oversteet, he thinks recovering stale data is a bug to fix, and option to permit it is unnecessary. So this version the sysfs file is removed. v2: rename sysfs entry from allow_stale_data_on_failure to allow_stale_data_on_failure, and fix the confusing commit log. v1: initial patch posted. [small change to patch comment spelling by mlyle] Signed-off-by: Coly Li <colyli(a)suse.de> Signed-off-by: Michael Lyle <mlyle(a)lyle.org> Reported-by: Arne Wolf <awolf(a)lenovo.com> Reviewed-by: Michael Lyle <mlyle(a)lyle.org> Cc: Kent Overstreet <kent.overstreet(a)gmail.com> Cc: Nix <nix(a)esperi.org.uk> Cc: Kai Krakow <hurikhan77(a)gmail.com> Cc: Eric Wheeler <bcache(a)lists.ewheeler.net> Cc: Junhui Tang <tang.junhui(a)zte.com.cn> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/md/bcache/request.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -705,8 +705,16 @@ static void cached_dev_read_error(struct { struct search *s = container_of(cl, struct search, cl); struct bio *bio = &s->bio.bio; + struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); - if (s->recoverable) { + /* + * If cache device is dirty (dc->has_dirty is non-zero), then + * recovery a failed read request from cached device may get a + * stale data back. So read failure recovery is only permitted + * when cache device is clean. + */ + if (s->recoverable && + (dc && !atomic_read(&dc->has_dirty))) { /* Retry from the backing device: */ trace_bcache_read_retry(s->orig_bio); Patches currently in stable-queue which might be from colyli(a)suse.de are queue-3.18/bcache-only-permit-to-recovery-read-error-when-cache-device-is-clean.patch queue-3.18/bcache-recover-data-from-backing-when-data-is-clean.patch

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Linux-stable-mirror December 2017