Commit c36e2024 authored by Shiyang Ruan's avatar Shiyang Ruan Committed by Andrew Morton
Browse files

mm: introduce mf_dax_kill_procs() for fsdax case 

This new function is a variant of mf_generic_kill_procs that accepts a
file, offset pair instead of a struct to support multiple files sharing a
DAX mapping.  It is intended to be called by the file systems as part of
the memory_failure handler after the file system performed a reverse
mapping from the storage address to the file and file offset.

Link: https://lkml.kernel.org/r/20220603053738.1218681-6-ruansy.fnst@fujitsu.com


Signed-off-by: default avatarShiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 2f437eff

include/linux/mm.h

+2 −0
Original line number Diff line number Diff line
@@ -3178,6 +3178,8 @@ enum mf_flags { 
	MF_UNPOISON = 1 << 4,

	MF_SW_SIMULATED = 1 << 5,

};

int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index,

		      unsigned long count, int mf_flags);

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);

mm/memory-failure.c

+86 −10
Original line number Diff line number Diff line
@@ -297,10 +297,9 @@ 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;
@@ -340,9 +339,13 @@ 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.

 *

 * Notice: @fsdax_pgoff is used only when @p is a fsdax page.

 *   In other cases, such as anonymous and file-backend page, the address to be

 *   killed can be caculated by @p itself.

 */

static void add_to_kill(struct task_struct *tsk, struct page *p,

		       struct vm_area_struct *vma,

			pgoff_t fsdax_pgoff, struct vm_area_struct *vma,

			struct list_head *to_kill)

{

	struct to_kill *tk;
@@ -354,9 +357,15 @@ 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(fsdax_pgoff, 1, vma);

		tk->size_shift = dev_pagemap_mapping_shift(vma, tk->addr);

	} else

		tk->size_shift = page_shift(compound_head(p));



	/*
@@ -505,7 +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);
@@ -541,12 +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);

}



#ifdef 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.
@@ -1588,6 +1625,45 @@ static int mf_generic_kill_procs(unsigned long long pfn, int flags, 
	return rc;

}



#ifdef CONFIG_FS_DAX

/**

 * mf_dax_kill_procs - Collect and kill processes who are using this file range

 * @mapping:	address_space of 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);

	dax_entry_t cookie;

	struct page *page;

	size_t end = index + count;



	mf_flags |= MF_ACTION_REQUIRED | MF_MUST_KILL;



	for (; index < end; index++) {

		page = NULL;

		cookie = dax_lock_mapping_entry(mapping, index, &page);

		if (!cookie)

			return -EBUSY;

		if (!page)

			goto unlock;



		SetPageHWPoison(page);



		collect_procs_fsdax(page, mapping, index, &to_kill);

		unmap_and_kill(&to_kill, page_to_pfn(page), mapping,

				index, mf_flags);

unlock:

		dax_unlock_mapping_entry(mapping, index, cookie);

	}

	return 0;

}

EXPORT_SYMBOL_GPL(mf_dax_kill_procs);

#endif /* CONFIG_FS_DAX */



/*

 * Called from hugetlb code with hugetlb_lock held.

 *