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Commit da1aab3d authored by NeilBrown's avatar NeilBrown
Browse files

md/raid1: r1buf_pool_alloc: free allocate pages when subsequent allocation fails. 



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: a0787606
Cc: Kent Overstreet <koverstreet@google.com>
Cc: stable@vger.kernel.org (3.10+)
Reported-by: default avatarRussell King - ARM Linux <linux@arm.linux.org.uk>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 035328c2

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]);