diff mbox series

[v10,7/9] mm: Introduce mf_dax_kill_procs() for fsdax case

Message ID 20220127124058.1172422-8-ruansy.fnst@fujitsu.com (mailing list archive)
State New, archived
Headers show
Series fsdax: introduce fs query to support reflink | expand

Commit Message

Shiyang Ruan Jan. 27, 2022, 12:40 p.m. UTC
This function is called at the end of RMAP routine, i.e. filesystem
recovery function, to collect and kill processes using a shared page of
DAX file.  The difference with mf_generic_kill_procs() is, it accepts
file's (mapping,offset) instead of struct page because different files'
mappings and offsets may share the same page in fsdax mode.
It will be called when filesystem's RMAP results are found.

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
---
 include/linux/mm.h  |  4 ++
 mm/memory-failure.c | 91 +++++++++++++++++++++++++++++++++++++++------
 2 files changed, 84 insertions(+), 11 deletions(-)

Comments

Dan Williams Feb. 16, 2022, 1:47 a.m. UTC | #1
On Thu, Jan 27, 2022 at 4:41 AM Shiyang Ruan <ruansy.fnst@fujitsu.com> wrote:
>
> This function is called at the end of RMAP routine, i.e. filesystem
> recovery function, to collect and kill processes using a shared page of
> DAX file.  The difference with mf_generic_kill_procs() is, it accepts
> file's (mapping,offset) instead of struct page because different files'
> mappings and offsets may share the same page in fsdax mode.
> It will be called when filesystem's RMAP results are found.
>
> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> ---
>  include/linux/mm.h  |  4 ++
>  mm/memory-failure.c | 91 +++++++++++++++++++++++++++++++++++++++------
>  2 files changed, 84 insertions(+), 11 deletions(-)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 9b1d56c5c224..0420189e4788 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -3195,6 +3195,10 @@ enum mf_flags {
>         MF_SOFT_OFFLINE = 1 << 3,
>         MF_UNPOISON = 1 << 4,
>  };
> +#if IS_ENABLED(CONFIG_FS_DAX)
> +int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index,
> +                     unsigned long count, int mf_flags);
> +#endif /* CONFIG_FS_DAX */
>  extern int memory_failure(unsigned long pfn, int flags);
>  extern void memory_failure_queue(unsigned long pfn, int flags);
>  extern void memory_failure_queue_kick(int cpu);
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index b2d13eba1071..8d123cc4102e 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -304,10 +304,9 @@ void shake_page(struct page *p)
>  }
>  EXPORT_SYMBOL_GPL(shake_page);
>
> -static unsigned long dev_pagemap_mapping_shift(struct page *page,
> -               struct vm_area_struct *vma)
> +static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma,
> +               unsigned long address)
>  {
> -       unsigned long address = vma_address(page, vma);
>         unsigned long ret = 0;
>         pgd_t *pgd;
>         p4d_t *p4d;
> @@ -347,9 +346,8 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page,
>   * Schedule a process for later kill.
>   * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM.
>   */
> -static void add_to_kill(struct task_struct *tsk, struct page *p,
> -                      struct vm_area_struct *vma,
> -                      struct list_head *to_kill)
> +static void add_to_kill(struct task_struct *tsk, struct page *p, pgoff_t pgoff,
> +                       struct vm_area_struct *vma, struct list_head *to_kill)
>  {
>         struct to_kill *tk;
>
> @@ -360,9 +358,15 @@ static void add_to_kill(struct task_struct *tsk, struct page *p,
>         }
>
>         tk->addr = page_address_in_vma(p, vma);
> -       if (is_zone_device_page(p))
> -               tk->size_shift = dev_pagemap_mapping_shift(p, vma);
> -       else
> +       if (is_zone_device_page(p)) {
> +               /*
> +                * Since page->mapping is not used for fsdax, we need
> +                * calculate the address based on the vma.
> +                */
> +               if (p->pgmap->type == MEMORY_DEVICE_FS_DAX)
> +                       tk->addr = vma_pgoff_address(vma, pgoff);
> +               tk->size_shift = dev_pagemap_mapping_shift(vma, tk->addr);
> +       } else
>                 tk->size_shift = page_shift(compound_head(p));
>
>         /*
> @@ -510,7 +514,7 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill,
>                         if (!page_mapped_in_vma(page, vma))
>                                 continue;
>                         if (vma->vm_mm == t->mm)
> -                               add_to_kill(t, page, vma, to_kill);
> +                               add_to_kill(t, page, 0, vma, to_kill);

Why is the @pgoff argument 0? @pgoff is available. Not that I expect
dax pages will ever be anonymous, might as well not leave that land
mine for future refactoring.

Other than that you can add:

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Dan Williams Feb. 16, 2022, 1:49 a.m. UTC | #2
On Thu, Jan 27, 2022 at 4:41 AM Shiyang Ruan <ruansy.fnst@fujitsu.com> wrote:
>
> This function is called at the end of RMAP routine, i.e. filesystem
> recovery function, to collect and kill processes using a shared page of
> DAX file.  The difference with mf_generic_kill_procs() is, it accepts
> file's (mapping,offset) instead of struct page because different files'
> mappings and offsets may share the same page in fsdax mode.
> It will be called when filesystem's RMAP results are found.
>
> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> ---
>  include/linux/mm.h  |  4 ++
>  mm/memory-failure.c | 91 +++++++++++++++++++++++++++++++++++++++------
>  2 files changed, 84 insertions(+), 11 deletions(-)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 9b1d56c5c224..0420189e4788 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -3195,6 +3195,10 @@ enum mf_flags {
>         MF_SOFT_OFFLINE = 1 << 3,
>         MF_UNPOISON = 1 << 4,
>  };
> +#if IS_ENABLED(CONFIG_FS_DAX)
> +int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index,
> +                     unsigned long count, int mf_flags);
> +#endif /* CONFIG_FS_DAX */
>  extern int memory_failure(unsigned long pfn, int flags);
>  extern void memory_failure_queue(unsigned long pfn, int flags);
>  extern void memory_failure_queue_kick(int cpu);
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index b2d13eba1071..8d123cc4102e 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -304,10 +304,9 @@ void shake_page(struct page *p)
>  }
>  EXPORT_SYMBOL_GPL(shake_page);
>
> -static unsigned long dev_pagemap_mapping_shift(struct page *page,
> -               struct vm_area_struct *vma)
> +static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma,
> +               unsigned long address)
>  {
> -       unsigned long address = vma_address(page, vma);
>         unsigned long ret = 0;
>         pgd_t *pgd;
>         p4d_t *p4d;
> @@ -347,9 +346,8 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page,
>   * Schedule a process for later kill.
>   * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM.
>   */
> -static void add_to_kill(struct task_struct *tsk, struct page *p,
> -                      struct vm_area_struct *vma,
> -                      struct list_head *to_kill)
> +static void add_to_kill(struct task_struct *tsk, struct page *p, pgoff_t pgoff,
> +                       struct vm_area_struct *vma, struct list_head *to_kill)
>  {
>         struct to_kill *tk;
>
> @@ -360,9 +358,15 @@ static void add_to_kill(struct task_struct *tsk, struct page *p,
>         }
>
>         tk->addr = page_address_in_vma(p, vma);
> -       if (is_zone_device_page(p))
> -               tk->size_shift = dev_pagemap_mapping_shift(p, vma);
> -       else
> +       if (is_zone_device_page(p)) {
> +               /*
> +                * Since page->mapping is not used for fsdax, we need
> +                * calculate the address based on the vma.
> +                */
> +               if (p->pgmap->type == MEMORY_DEVICE_FS_DAX)
> +                       tk->addr = vma_pgoff_address(vma, pgoff);
> +               tk->size_shift = dev_pagemap_mapping_shift(vma, tk->addr);
> +       } else
>                 tk->size_shift = page_shift(compound_head(p));
>
>         /*
> @@ -510,7 +514,7 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill,
>                         if (!page_mapped_in_vma(page, vma))
>                                 continue;
>                         if (vma->vm_mm == t->mm)
> -                               add_to_kill(t, page, vma, to_kill);
> +                               add_to_kill(t, page, 0, vma, to_kill);
>                 }
>         }
>         read_unlock(&tasklist_lock);
> @@ -546,12 +550,40 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
>                          * to be informed of all such data corruptions.
>                          */
>                         if (vma->vm_mm == t->mm)
> -                               add_to_kill(t, page, vma, to_kill);
> +                               add_to_kill(t, page, 0, vma, to_kill);
> +               }
> +       }
> +       read_unlock(&tasklist_lock);
> +       i_mmap_unlock_read(mapping);
> +}
> +
> +#if IS_ENABLED(CONFIG_FS_DAX)
> +/*
> + * Collect processes when the error hit a fsdax page.
> + */
> +static void collect_procs_fsdax(struct page *page,
> +               struct address_space *mapping, pgoff_t pgoff,
> +               struct list_head *to_kill)
> +{
> +       struct vm_area_struct *vma;
> +       struct task_struct *tsk;
> +
> +       i_mmap_lock_read(mapping);
> +       read_lock(&tasklist_lock);
> +       for_each_process(tsk) {
> +               struct task_struct *t = task_early_kill(tsk, true);
> +
> +               if (!t)
> +                       continue;
> +               vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
> +                       if (vma->vm_mm == t->mm)
> +                               add_to_kill(t, page, pgoff, vma, to_kill);
>                 }
>         }
>         read_unlock(&tasklist_lock);
>         i_mmap_unlock_read(mapping);
>  }
> +#endif /* CONFIG_FS_DAX */
>
>  /*
>   * Collect the processes who have the corrupted page mapped to kill.
> @@ -1574,6 +1606,43 @@ static int mf_generic_kill_procs(unsigned long long pfn, int flags,
>         return 0;
>  }
>
> +#if IS_ENABLED(CONFIG_FS_DAX)
> +/**
> + * mf_dax_kill_procs - Collect and kill processes who are using this file range
> + * @mapping:   the file in use
> + * @index:     start pgoff of the range within the file
> + * @count:     length of the range, in unit of PAGE_SIZE
> + * @mf_flags:  memory failure flags
> + */
> +int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index,
> +               unsigned long count, int mf_flags)
> +{
> +       LIST_HEAD(to_kill);
> +       int rc;
> +       struct page *page;
> +       size_t end = index + count;
> +
> +       mf_flags |= MF_ACTION_REQUIRED | MF_MUST_KILL;
> +
> +       for (; index < end; index++) {
> +               page = NULL;
> +               rc = dax_load_page(mapping, index, &page);
> +               if (rc)
> +                       return rc;
> +               if (!page)
> +                       continue;
> +
> +               SetPageHWPoison(page);
> +
> +               collect_procs_fsdax(page, mapping, index, &to_kill);
> +               unmap_and_kill(&to_kill, page_to_pfn(page), mapping,
> +                               index, mf_flags);

Depending on the answer to the question in patch5 there may need to be
a put_page() or dax_unlock_page() here.
diff mbox series

Patch

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9b1d56c5c224..0420189e4788 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3195,6 +3195,10 @@  enum mf_flags {
 	MF_SOFT_OFFLINE = 1 << 3,
 	MF_UNPOISON = 1 << 4,
 };
+#if IS_ENABLED(CONFIG_FS_DAX)
+int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index,
+		      unsigned long count, int mf_flags);
+#endif /* CONFIG_FS_DAX */
 extern int memory_failure(unsigned long pfn, int flags);
 extern void memory_failure_queue(unsigned long pfn, int flags);
 extern void memory_failure_queue_kick(int cpu);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index b2d13eba1071..8d123cc4102e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -304,10 +304,9 @@  void shake_page(struct page *p)
 }
 EXPORT_SYMBOL_GPL(shake_page);
 
-static unsigned long dev_pagemap_mapping_shift(struct page *page,
-		struct vm_area_struct *vma)
+static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma,
+		unsigned long address)
 {
-	unsigned long address = vma_address(page, vma);
 	unsigned long ret = 0;
 	pgd_t *pgd;
 	p4d_t *p4d;
@@ -347,9 +346,8 @@  static unsigned long dev_pagemap_mapping_shift(struct page *page,
  * Schedule a process for later kill.
  * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM.
  */
-static void add_to_kill(struct task_struct *tsk, struct page *p,
-		       struct vm_area_struct *vma,
-		       struct list_head *to_kill)
+static void add_to_kill(struct task_struct *tsk, struct page *p, pgoff_t pgoff,
+			struct vm_area_struct *vma, struct list_head *to_kill)
 {
 	struct to_kill *tk;
 
@@ -360,9 +358,15 @@  static void add_to_kill(struct task_struct *tsk, struct page *p,
 	}
 
 	tk->addr = page_address_in_vma(p, vma);
-	if (is_zone_device_page(p))
-		tk->size_shift = dev_pagemap_mapping_shift(p, vma);
-	else
+	if (is_zone_device_page(p)) {
+		/*
+		 * Since page->mapping is not used for fsdax, we need
+		 * calculate the address based on the vma.
+		 */
+		if (p->pgmap->type == MEMORY_DEVICE_FS_DAX)
+			tk->addr = vma_pgoff_address(vma, pgoff);
+		tk->size_shift = dev_pagemap_mapping_shift(vma, tk->addr);
+	} else
 		tk->size_shift = page_shift(compound_head(p));
 
 	/*
@@ -510,7 +514,7 @@  static void collect_procs_anon(struct page *page, struct list_head *to_kill,
 			if (!page_mapped_in_vma(page, vma))
 				continue;
 			if (vma->vm_mm == t->mm)
-				add_to_kill(t, page, vma, to_kill);
+				add_to_kill(t, page, 0, vma, to_kill);
 		}
 	}
 	read_unlock(&tasklist_lock);
@@ -546,12 +550,40 @@  static void collect_procs_file(struct page *page, struct list_head *to_kill,
 			 * to be informed of all such data corruptions.
 			 */
 			if (vma->vm_mm == t->mm)
-				add_to_kill(t, page, vma, to_kill);
+				add_to_kill(t, page, 0, vma, to_kill);
+		}
+	}
+	read_unlock(&tasklist_lock);
+	i_mmap_unlock_read(mapping);
+}
+
+#if IS_ENABLED(CONFIG_FS_DAX)
+/*
+ * Collect processes when the error hit a fsdax page.
+ */
+static void collect_procs_fsdax(struct page *page,
+		struct address_space *mapping, pgoff_t pgoff,
+		struct list_head *to_kill)
+{
+	struct vm_area_struct *vma;
+	struct task_struct *tsk;
+
+	i_mmap_lock_read(mapping);
+	read_lock(&tasklist_lock);
+	for_each_process(tsk) {
+		struct task_struct *t = task_early_kill(tsk, true);
+
+		if (!t)
+			continue;
+		vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
+			if (vma->vm_mm == t->mm)
+				add_to_kill(t, page, pgoff, vma, to_kill);
 		}
 	}
 	read_unlock(&tasklist_lock);
 	i_mmap_unlock_read(mapping);
 }
+#endif /* CONFIG_FS_DAX */
 
 /*
  * Collect the processes who have the corrupted page mapped to kill.
@@ -1574,6 +1606,43 @@  static int mf_generic_kill_procs(unsigned long long pfn, int flags,
 	return 0;
 }
 
+#if IS_ENABLED(CONFIG_FS_DAX)
+/**
+ * mf_dax_kill_procs - Collect and kill processes who are using this file range
+ * @mapping:	the file in use
+ * @index:	start pgoff of the range within the file
+ * @count:	length of the range, in unit of PAGE_SIZE
+ * @mf_flags:	memory failure flags
+ */
+int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index,
+		unsigned long count, int mf_flags)
+{
+	LIST_HEAD(to_kill);
+	int rc;
+	struct page *page;
+	size_t end = index + count;
+
+	mf_flags |= MF_ACTION_REQUIRED | MF_MUST_KILL;
+
+	for (; index < end; index++) {
+		page = NULL;
+		rc = dax_load_page(mapping, index, &page);
+		if (rc)
+			return rc;
+		if (!page)
+			continue;
+
+		SetPageHWPoison(page);
+
+		collect_procs_fsdax(page, mapping, index, &to_kill);
+		unmap_and_kill(&to_kill, page_to_pfn(page), mapping,
+				index, mf_flags);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mf_dax_kill_procs);
+#endif /* CONFIG_FS_DAX */
+
 static int memory_failure_hugetlb(unsigned long pfn, int flags)
 {
 	struct page *p = pfn_to_page(pfn);