From: NeilBrown Date: Wed, 9 Apr 2014 02:25:43 +0000 (+1000) Subject: md/raid1: r1buf_pool_alloc: free allocate pages when subsequent allocation fails. X-Git-Tag: firefly_0821_release~176^2~4040^2~4 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=da1aab3dca9aa88ae34ca392470b8943159e25fe;p=firefly-linux-kernel-4.4.55.git 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: a07876064a0b73ab5ef1ebcf14b1cf0231c07858 Cc: Kent Overstreet Cc: stable@vger.kernel.org (3.10+) Reported-by: Russell King - ARM Linux Signed-off-by: NeilBrown --- diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 4a6ca1cb2e78..56e24c072b62 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -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]);