Commit d0473f97 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-5.1-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux 

Pull btrfs fix from David Sterba:
 "One patch to fix a crash in io submission path, due to memory
  allocation errors.

  In short, the multipage bio work that landed in 5.1 caused larger bios
  that in turn require larger temporary memory for checksums. The patch
  is a workaround, we're going to rework the allocation so it does not
  require the vmalloc fallback.

  It took a while to identify that it's caused by patches in 5.1 and not
  a patchset that did some changes in error handling in the code. I've
  tested it on various memory/cpu combinations, it could hit OOM but
  does not crash.

  The timestamp of the patch is less than a day due to updates in the
  changelog, tests were running meanwhile"

* tag 'for-5.1-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: Switch memory allocations in async csum calculation path to kvmalloc
parents 58130235 a3d46aea

fs/btrfs/file-item.c

+11 −4
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/slab.h>

#include <linux/pagemap.h>

#include <linux/highmem.h>

#include <linux/sched/mm.h>

#include "ctree.h"

#include "disk-io.h"

#include "transaction.h"
@@ -427,9 +428,13 @@ blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio, 
	unsigned long this_sum_bytes = 0;

	int i;

	u64 offset;

	unsigned nofs_flag;



	nofs_flag = memalloc_nofs_save();

	sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),

		       GFP_KERNEL);

	memalloc_nofs_restore(nofs_flag);



	sums = kzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),

		       GFP_NOFS);

	if (!sums)

		return BLK_STS_RESOURCE;
@@ -472,8 +477,10 @@ blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio, 


				bytes_left = bio->bi_iter.bi_size - total_bytes;



				sums = kzalloc(btrfs_ordered_sum_size(fs_info, bytes_left),

					       GFP_NOFS);

				nofs_flag = memalloc_nofs_save();

				sums = kvzalloc(btrfs_ordered_sum_size(fs_info,

						      bytes_left), GFP_KERNEL);

				memalloc_nofs_restore(nofs_flag);

				BUG_ON(!sums); /* -ENOMEM */

				sums->len = bytes_left;

				ordered = btrfs_lookup_ordered_extent(inode,

fs/btrfs/ordered-data.c

+2 −1
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <linux/slab.h>

#include <linux/blkdev.h>

#include <linux/writeback.h>

#include <linux/sched/mm.h>

#include "ctree.h"

#include "transaction.h"

#include "btrfs_inode.h"
@@ -442,7 +443,7 @@ void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry) 
			cur = entry->list.next;

			sum = list_entry(cur, struct btrfs_ordered_sum, list);

			list_del(&sum->list);

			kfree(sum);

			kvfree(sum);

		}

		kmem_cache_free(btrfs_ordered_extent_cache, entry);

	}

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