raid5: remove gfp flags from scribble_alloc() (ba54d4d4) · Commits · 戴 / test

Using GFP_NOIO flag to call scribble_alloc() from resize_chunk() does not have the expected behavior. kvmalloc_array() inside scribble_alloc() which receives the GFP_NOIO flag will eventually call kmalloc_node() to allocate physically continuous pages. Now we have memalloc scope APIs in mddev_suspend()/mddev_resume() to prevent memory reclaim I/Os during raid array suspend context, calling to kvmalloc_array() with GFP_KERNEL flag may avoid deadlock of recursive I/O as expected. This patch removes the useless gfp flags from parameters list of scribble_alloc(), and call kvmalloc_array() with GFP_KERNEL flag. The incorrect GFP_NOIO flag does not exist anymore. Fixes: ("md: convert to kvmalloc") Suggested-by:

Michal Hocko <mhocko@suse.com> Signed-off-by:

Coly Li <colyli@suse.de> Signed-off-by:

Song Liu <songliubraving@fb.com>

drivers/md/raid5.c

+9 −6

Original line number	Diff line number	Diff line
		@@ -2228,14 +2228,19 @@ static int grow_stripes(struct r5conf *conf, int num)
		* of the P and Q blocks.
		*/
		static int scribble_alloc(struct raid5_percpu *percpu,
		int num, int cnt, gfp_t flags)
		int num, int cnt)
		{
		size_t obj_size =
		sizeof(struct page ) (num+2) +
		sizeof(addr_conv_t) * (num+2);
		void *scribble;

		scribble = kvmalloc_array(cnt, obj_size, flags);
		/*
		* If here is in raid array suspend context, it is in memalloc noio
		* context as well, there is no potential recursive memory reclaim
		* I/Os with the GFP_KERNEL flag.
		*/
		scribble = kvmalloc_array(cnt, obj_size, GFP_KERNEL);
		if (!scribble)
		return -ENOMEM;

		@@ -2267,8 +2272,7 @@ static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors)

		percpu = per_cpu_ptr(conf->percpu, cpu);
		err = scribble_alloc(percpu, new_disks,
		new_sectors / STRIPE_SECTORS,
		GFP_NOIO);
		new_sectors / STRIPE_SECTORS);
		if (err)
		break;
		}
		@@ -6759,8 +6763,7 @@ static int alloc_scratch_buffer(struct r5conf conf, struct raid5_percpu percpu
		conf->previous_raid_disks),
		max(conf->chunk_sectors,
		conf->prev_chunk_sectors)
		/ STRIPE_SECTORS,
		GFP_KERNEL)) {
		/ STRIPE_SECTORS)) {
		free_scratch_buffer(conf, percpu);
		return -ENOMEM;
		}

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