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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: a07876064a
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>
hifive-unleashed-5.1
NeilBrown 2014-04-09 12:25:43 +10:00
parent 035328c202
commit da1aab3dca
1 changed files with 13 additions and 4 deletions
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17
drivers/md/raid1.c
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@ -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]);