* FAILED: patch "[PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry" failed to apply to 4.19-stable tree @ 2018-11-26 10:40 gregkh 2018-11-26 12:22 ` Matthew Wilcox 0 siblings, 1 reply; 9+ messages in thread From: gregkh @ 2018-11-26 10:40 UTC (permalink / raw) To: willy; +Cc: stable The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 25bbe21bf427a81b8e3ccd480ea0e1d940256156 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox <willy@infradead.org> Date: Fri, 16 Nov 2018 15:50:02 -0500 Subject: [PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry After calling get_unlocked_entry(), you have to call put_unlocked_entry() to avoid subsequent waiters losing wakeups. Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") Cc: stable@vger.kernel.org Signed-off-by: Matthew Wilcox <willy@infradead.org> diff --git a/fs/dax.c b/fs/dax.c index cf2394e2bf4b..9bcce89ea18e 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -391,6 +391,7 @@ bool dax_lock_mapping_entry(struct page *page) rcu_read_unlock(); entry = get_unlocked_entry(&xas); xas_unlock_irq(&xas); + put_unlocked_entry(&xas, entry); rcu_read_lock(); continue; } ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: FAILED: patch "[PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry" failed to apply to 4.19-stable tree 2018-11-26 10:40 FAILED: patch "[PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry" failed to apply to 4.19-stable tree gregkh @ 2018-11-26 12:22 ` Matthew Wilcox 0 siblings, 0 replies; 9+ messages in thread From: Matthew Wilcox @ 2018-11-26 12:22 UTC (permalink / raw) To: gregkh; +Cc: stable, linux-nvdimm On Mon, Nov 26, 2018 at 11:40:20AM +0100, gregkh@linuxfoundation.org wrote: > > The patch below does not apply to the 4.19-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to <stable@vger.kernel.org>. The fix for 4.19 is rather more complex because we don't have the right information in the right places. Dan, does this look right to you? diff --git a/fs/dax.c b/fs/dax.c index 0fb270f0a0ef6..b8dd66f1951a6 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -227,7 +227,9 @@ static inline void *unlock_slot(struct address_space *mapping, void **slot) * Must be called with the i_pages lock held. */ static void *__get_unlocked_mapping_entry(struct address_space *mapping, - pgoff_t index, void ***slotp, bool (*wait_fn)(void)) + pgoff_t index, void ***slotp, + bool (*wait_fn)(struct address_space *mapping, + pgoff_t index, void *entry)) { void *entry, **slot; struct wait_exceptional_entry_queue ewait; @@ -253,7 +255,7 @@ static void *__get_unlocked_mapping_entry(struct address_space *mapping, prepare_to_wait_exclusive(wq, &ewait.wait, TASK_UNINTERRUPTIBLE); xa_unlock_irq(&mapping->i_pages); - revalidate = wait_fn(); + revalidate = wait_fn(mapping, index, entry); finish_wait(wq, &ewait.wait); xa_lock_irq(&mapping->i_pages); if (revalidate) @@ -261,7 +263,8 @@ static void *__get_unlocked_mapping_entry(struct address_space *mapping, } } -static bool entry_wait(void) +static bool entry_wait(struct address_space *mapping, unsigned long index, + void *entry) { schedule(); /* @@ -393,12 +396,18 @@ static struct page *dax_busy_page(void *entry) return NULL; } -static bool entry_wait_revalidate(void) +static bool entry_wait_revalidate(struct address_space *mapping, + unsigned long index, void *entry) { rcu_read_unlock(); schedule(); rcu_read_lock(); + /* + * We're not going to do anything with this entry; wake the next + * task in line + */ + put_unlocked_mapping_entry(mapping, index, entry); /* * Tell __get_unlocked_mapping_entry() to take a break, we need * to revalidate page->mapping after dropping locks > ------------------ original commit in Linus's tree ------------------ > > >From 25bbe21bf427a81b8e3ccd480ea0e1d940256156 Mon Sep 17 00:00:00 2001 > From: Matthew Wilcox <willy@infradead.org> > Date: Fri, 16 Nov 2018 15:50:02 -0500 > Subject: [PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry > > After calling get_unlocked_entry(), you have to call > put_unlocked_entry() to avoid subsequent waiters losing wakeups. > > Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") > Cc: stable@vger.kernel.org > Signed-off-by: Matthew Wilcox <willy@infradead.org> > > diff --git a/fs/dax.c b/fs/dax.c > index cf2394e2bf4b..9bcce89ea18e 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -391,6 +391,7 @@ bool dax_lock_mapping_entry(struct page *page) > rcu_read_unlock(); > entry = get_unlocked_entry(&xas); > xas_unlock_irq(&xas); > + put_unlocked_entry(&xas, entry); > rcu_read_lock(); > continue; > } > _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: FAILED: patch "[PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry" failed to apply to 4.19-stable tree @ 2018-11-26 12:22 ` Matthew Wilcox 0 siblings, 0 replies; 9+ messages in thread From: Matthew Wilcox @ 2018-11-26 12:22 UTC (permalink / raw) To: gregkh; +Cc: stable, linux-nvdimm, Dan Williams On Mon, Nov 26, 2018 at 11:40:20AM +0100, gregkh@linuxfoundation.org wrote: > > The patch below does not apply to the 4.19-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to <stable@vger.kernel.org>. The fix for 4.19 is rather more complex because we don't have the right information in the right places. Dan, does this look right to you? diff --git a/fs/dax.c b/fs/dax.c index 0fb270f0a0ef6..b8dd66f1951a6 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -227,7 +227,9 @@ static inline void *unlock_slot(struct address_space *mapping, void **slot) * Must be called with the i_pages lock held. */ static void *__get_unlocked_mapping_entry(struct address_space *mapping, - pgoff_t index, void ***slotp, bool (*wait_fn)(void)) + pgoff_t index, void ***slotp, + bool (*wait_fn)(struct address_space *mapping, + pgoff_t index, void *entry)) { void *entry, **slot; struct wait_exceptional_entry_queue ewait; @@ -253,7 +255,7 @@ static void *__get_unlocked_mapping_entry(struct address_space *mapping, prepare_to_wait_exclusive(wq, &ewait.wait, TASK_UNINTERRUPTIBLE); xa_unlock_irq(&mapping->i_pages); - revalidate = wait_fn(); + revalidate = wait_fn(mapping, index, entry); finish_wait(wq, &ewait.wait); xa_lock_irq(&mapping->i_pages); if (revalidate) @@ -261,7 +263,8 @@ static void *__get_unlocked_mapping_entry(struct address_space *mapping, } } -static bool entry_wait(void) +static bool entry_wait(struct address_space *mapping, unsigned long index, + void *entry) { schedule(); /* @@ -393,12 +396,18 @@ static struct page *dax_busy_page(void *entry) return NULL; } -static bool entry_wait_revalidate(void) +static bool entry_wait_revalidate(struct address_space *mapping, + unsigned long index, void *entry) { rcu_read_unlock(); schedule(); rcu_read_lock(); + /* + * We're not going to do anything with this entry; wake the next + * task in line + */ + put_unlocked_mapping_entry(mapping, index, entry); /* * Tell __get_unlocked_mapping_entry() to take a break, we need * to revalidate page->mapping after dropping locks > ------------------ original commit in Linus's tree ------------------ > > >From 25bbe21bf427a81b8e3ccd480ea0e1d940256156 Mon Sep 17 00:00:00 2001 > From: Matthew Wilcox <willy@infradead.org> > Date: Fri, 16 Nov 2018 15:50:02 -0500 > Subject: [PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry > > After calling get_unlocked_entry(), you have to call > put_unlocked_entry() to avoid subsequent waiters losing wakeups. > > Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") > Cc: stable@vger.kernel.org > Signed-off-by: Matthew Wilcox <willy@infradead.org> > > diff --git a/fs/dax.c b/fs/dax.c > index cf2394e2bf4b..9bcce89ea18e 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -391,6 +391,7 @@ bool dax_lock_mapping_entry(struct page *page) > rcu_read_unlock(); > entry = get_unlocked_entry(&xas); > xas_unlock_irq(&xas); > + put_unlocked_entry(&xas, entry); > rcu_read_lock(); > continue; > } > ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: FAILED: patch "[PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry" failed to apply to 4.19-stable tree 2018-11-26 12:22 ` Matthew Wilcox @ 2018-11-26 14:27 ` Matthew Wilcox -1 siblings, 0 replies; 9+ messages in thread From: Matthew Wilcox @ 2018-11-26 14:27 UTC (permalink / raw) To: gregkh; +Cc: stable, linux-nvdimm On Mon, Nov 26, 2018 at 04:22:23AM -0800, Matthew Wilcox wrote: > On Mon, Nov 26, 2018 at 11:40:20AM +0100, gregkh@linuxfoundation.org wrote: > > > > The patch below does not apply to the 4.19-stable tree. > > If someone wants it applied there, or to any other stable or longterm > > tree, then please email the backport, including the original git commit > > id to <stable@vger.kernel.org>. > > The fix for 4.19 is rather more complex because we don't have the > right information in the right places. Dan, does this look right to you? Wait, we can do it like this which should be simpler: diff --git a/fs/dax.c b/fs/dax.c index 0fb270f0a0ef6..b0cd1364c68fa 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -217,6 +217,9 @@ static inline void *unlock_slot(struct address_space *mapping, void **slot) return (void *)entry; } +static void put_unlocked_mapping_entry(struct address_space *mapping, + pgoff_t index, void *entry); + /* * Lookup entry in radix tree, wait for it to become unlocked if it is * exceptional entry and return it. The caller must call @@ -256,8 +259,10 @@ static void *__get_unlocked_mapping_entry(struct address_space *mapping, revalidate = wait_fn(); finish_wait(wq, &ewait.wait); xa_lock_irq(&mapping->i_pages); - if (revalidate) + if (revalidate) { + put_unlocked_mapping_entry(mapping, index, entry); return ERR_PTR(-EAGAIN); + } } } > > ------------------ original commit in Linus's tree ------------------ > > > > >From 25bbe21bf427a81b8e3ccd480ea0e1d940256156 Mon Sep 17 00:00:00 2001 > > From: Matthew Wilcox <willy@infradead.org> > > Date: Fri, 16 Nov 2018 15:50:02 -0500 > > Subject: [PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry > > > > After calling get_unlocked_entry(), you have to call > > put_unlocked_entry() to avoid subsequent waiters losing wakeups. > > > > Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") > > Cc: stable@vger.kernel.org > > Signed-off-by: Matthew Wilcox <willy@infradead.org> > > > > diff --git a/fs/dax.c b/fs/dax.c > > index cf2394e2bf4b..9bcce89ea18e 100644 > > --- a/fs/dax.c > > +++ b/fs/dax.c > > @@ -391,6 +391,7 @@ bool dax_lock_mapping_entry(struct page *page) > > rcu_read_unlock(); > > entry = get_unlocked_entry(&xas); > > xas_unlock_irq(&xas); > > + put_unlocked_entry(&xas, entry); > > rcu_read_lock(); > > continue; > > } > > _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: FAILED: patch "[PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry" failed to apply to 4.19-stable tree @ 2018-11-26 14:27 ` Matthew Wilcox 0 siblings, 0 replies; 9+ messages in thread From: Matthew Wilcox @ 2018-11-26 14:27 UTC (permalink / raw) To: gregkh; +Cc: stable, linux-nvdimm, Dan Williams On Mon, Nov 26, 2018 at 04:22:23AM -0800, Matthew Wilcox wrote: > On Mon, Nov 26, 2018 at 11:40:20AM +0100, gregkh@linuxfoundation.org wrote: > > > > The patch below does not apply to the 4.19-stable tree. > > If someone wants it applied there, or to any other stable or longterm > > tree, then please email the backport, including the original git commit > > id to <stable@vger.kernel.org>. > > The fix for 4.19 is rather more complex because we don't have the > right information in the right places. Dan, does this look right to you? Wait, we can do it like this which should be simpler: diff --git a/fs/dax.c b/fs/dax.c index 0fb270f0a0ef6..b0cd1364c68fa 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -217,6 +217,9 @@ static inline void *unlock_slot(struct address_space *mapping, void **slot) return (void *)entry; } +static void put_unlocked_mapping_entry(struct address_space *mapping, + pgoff_t index, void *entry); + /* * Lookup entry in radix tree, wait for it to become unlocked if it is * exceptional entry and return it. The caller must call @@ -256,8 +259,10 @@ static void *__get_unlocked_mapping_entry(struct address_space *mapping, revalidate = wait_fn(); finish_wait(wq, &ewait.wait); xa_lock_irq(&mapping->i_pages); - if (revalidate) + if (revalidate) { + put_unlocked_mapping_entry(mapping, index, entry); return ERR_PTR(-EAGAIN); + } } } > > ------------------ original commit in Linus's tree ------------------ > > > > >From 25bbe21bf427a81b8e3ccd480ea0e1d940256156 Mon Sep 17 00:00:00 2001 > > From: Matthew Wilcox <willy@infradead.org> > > Date: Fri, 16 Nov 2018 15:50:02 -0500 > > Subject: [PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry > > > > After calling get_unlocked_entry(), you have to call > > put_unlocked_entry() to avoid subsequent waiters losing wakeups. > > > > Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") > > Cc: stable@vger.kernel.org > > Signed-off-by: Matthew Wilcox <willy@infradead.org> > > > > diff --git a/fs/dax.c b/fs/dax.c > > index cf2394e2bf4b..9bcce89ea18e 100644 > > --- a/fs/dax.c > > +++ b/fs/dax.c > > @@ -391,6 +391,7 @@ bool dax_lock_mapping_entry(struct page *page) > > rcu_read_unlock(); > > entry = get_unlocked_entry(&xas); > > xas_unlock_irq(&xas); > > + put_unlocked_entry(&xas, entry); > > rcu_read_lock(); > > continue; > > } > > ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [4.19-stable PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry 2018-11-26 14:27 ` Matthew Wilcox @ 2018-11-28 18:53 ` Dan Williams -1 siblings, 0 replies; 9+ messages in thread From: Dan Williams @ 2018-11-28 18:53 UTC (permalink / raw) To: stable; +Cc: linux-fsdevel, linux-kernel, Matthew Wilcox, linux-nvdimm From: Matthew Wilcox <willy@infradead.org> commit 25bbe21bf427a81b8e3ccd480ea0e1d940256156 upstream. After calling get_unlocked_entry(), you have to call put_unlocked_entry() to avoid subsequent waiters losing wakeups. Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") Cc: <stable@vger.kernel.org> Signed-off-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- Passes the nvdimm unit test suite which exercises the lock path. fs/dax.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/dax.c b/fs/dax.c index 0fb270f0a0ef..b0cd1364c68f 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -217,6 +217,9 @@ static inline void *unlock_slot(struct address_space *mapping, void **slot) return (void *)entry; } +static void put_unlocked_mapping_entry(struct address_space *mapping, + pgoff_t index, void *entry); + /* * Lookup entry in radix tree, wait for it to become unlocked if it is * exceptional entry and return it. The caller must call @@ -256,8 +259,10 @@ static void *__get_unlocked_mapping_entry(struct address_space *mapping, revalidate = wait_fn(); finish_wait(wq, &ewait.wait); xa_lock_irq(&mapping->i_pages); - if (revalidate) + if (revalidate) { + put_unlocked_mapping_entry(mapping, index, entry); return ERR_PTR(-EAGAIN); + } } } _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [4.19-stable PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry @ 2018-11-28 18:53 ` Dan Williams 0 siblings, 0 replies; 9+ messages in thread From: Dan Williams @ 2018-11-28 18:53 UTC (permalink / raw) To: stable; +Cc: Matthew Wilcox, linux-nvdimm, linux-kernel, linux-fsdevel From: Matthew Wilcox <willy@infradead.org> commit 25bbe21bf427a81b8e3ccd480ea0e1d940256156 upstream. After calling get_unlocked_entry(), you have to call put_unlocked_entry() to avoid subsequent waiters losing wakeups. Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") Cc: <stable@vger.kernel.org> Signed-off-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- Passes the nvdimm unit test suite which exercises the lock path. fs/dax.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/dax.c b/fs/dax.c index 0fb270f0a0ef..b0cd1364c68f 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -217,6 +217,9 @@ static inline void *unlock_slot(struct address_space *mapping, void **slot) return (void *)entry; } +static void put_unlocked_mapping_entry(struct address_space *mapping, + pgoff_t index, void *entry); + /* * Lookup entry in radix tree, wait for it to become unlocked if it is * exceptional entry and return it. The caller must call @@ -256,8 +259,10 @@ static void *__get_unlocked_mapping_entry(struct address_space *mapping, revalidate = wait_fn(); finish_wait(wq, &ewait.wait); xa_lock_irq(&mapping->i_pages); - if (revalidate) + if (revalidate) { + put_unlocked_mapping_entry(mapping, index, entry); return ERR_PTR(-EAGAIN); + } } } ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [4.19-stable PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry 2018-11-28 18:53 ` Dan Williams @ 2018-11-29 8:04 ` Greg KH -1 siblings, 0 replies; 9+ messages in thread From: Greg KH @ 2018-11-29 8:04 UTC (permalink / raw) To: Dan Williams Cc: linux-fsdevel, linux-kernel, Matthew Wilcox, stable, linux-nvdimm On Wed, Nov 28, 2018 at 10:53:44AM -0800, Dan Williams wrote: > From: Matthew Wilcox <willy@infradead.org> > > commit 25bbe21bf427a81b8e3ccd480ea0e1d940256156 upstream. > > After calling get_unlocked_entry(), you have to call > put_unlocked_entry() to avoid subsequent waiters losing wakeups. > > Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") > Cc: <stable@vger.kernel.org> > Signed-off-by: Matthew Wilcox <willy@infradead.org> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > Passes the nvdimm unit test suite which exercises the lock path. Now applied, thanks. greg k-h _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [4.19-stable PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry @ 2018-11-29 8:04 ` Greg KH 0 siblings, 0 replies; 9+ messages in thread From: Greg KH @ 2018-11-29 8:04 UTC (permalink / raw) To: Dan Williams Cc: stable, Matthew Wilcox, linux-nvdimm, linux-kernel, linux-fsdevel On Wed, Nov 28, 2018 at 10:53:44AM -0800, Dan Williams wrote: > From: Matthew Wilcox <willy@infradead.org> > > commit 25bbe21bf427a81b8e3ccd480ea0e1d940256156 upstream. > > After calling get_unlocked_entry(), you have to call > put_unlocked_entry() to avoid subsequent waiters losing wakeups. > > Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") > Cc: <stable@vger.kernel.org> > Signed-off-by: Matthew Wilcox <willy@infradead.org> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > Passes the nvdimm unit test suite which exercises the lock path. Now applied, thanks. greg k-h ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2018-11-29 19:09 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2018-11-26 10:40 FAILED: patch "[PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry" failed to apply to 4.19-stable tree gregkh 2018-11-26 12:22 ` Matthew Wilcox 2018-11-26 12:22 ` Matthew Wilcox 2018-11-26 14:27 ` Matthew Wilcox 2018-11-26 14:27 ` Matthew Wilcox 2018-11-28 18:53 ` [4.19-stable PATCH] dax: Avoid losing wakeup in dax_lock_mapping_entry Dan Williams 2018-11-28 18:53 ` Dan Williams 2018-11-29 8:04 ` Greg KH 2018-11-29 8:04 ` Greg KH
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