md/raid1: r1buf_pool_alloc: free allocate pages when subsequent allocation fails. (da1aab3d) · Commits · 戴 / test

When performing a user-request check/repair (MD_RECOVERY_REQUEST is set) on a raid1, we allocate multiple bios each with their own set of pages. If the page allocations for one bio fails, we currently do *not* free the pages allocated for the previous bios, nor do we free the bio itself. This patch frees all the already-allocate pages, and makes sure that all the bios are freed as well. This bug can cause a memory leak which can ultimately OOM a machine. It was introduced in 3.10-rc1. Fixes: Cc: Kent Overstreet <koverstreet@google.com> Cc: stable@vger.kernel.org (3.10+) Reported-by:

Russell King - ARM Linux <linux@arm.linux.org.uk> Signed-off-by:

NeilBrown <neilb@suse.de>

drivers/md/raid1.c

+13 −4

Original line number	Diff line number	Diff line
		@@ -97,6 +97,7 @@ static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
		struct pool_info *pi = data;
		struct r1bio *r1_bio;
		struct bio *bio;
		int need_pages;
		int i, j;

		r1_bio = r1bio_pool_alloc(gfp_flags, pi);
		@@ -119,15 +120,15 @@ static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
		* RESYNC_PAGES for each bio.
		*/
		if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
		j = pi->raid_disks;
		need_pages = pi->raid_disks;
		else
		j = 1;
		while(j--) {
		need_pages = 1;
		for (j = 0; j < need_pages; j++) {
		bio = r1_bio->bios[j];
		bio->bi_vcnt = RESYNC_PAGES;

		if (bio_alloc_pages(bio, gfp_flags))
		goto out_free_bio;
		goto out_free_pages;
		}
		/* If not user-requests, copy the page pointers to all bios */
		if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
		@@ -141,6 +142,14 @@ static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)

		return r1_bio;

		out_free_pages:
		while (--j >= 0) {
		struct bio_vec *bv;

		bio_for_each_segment_all(bv, r1_bio->bios[j], i)
		__free_page(bv->bv_page);
		}

		out_free_bio:
		while (++j < pi->raid_disks)
		bio_put(r1_bio->bios[j]);

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