md/raid10: fix problem with on-stack allocation of r10bio structure.

[deliverable/linux.git] / drivers / md / raid10.c

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index e2549deab7c3a87c9f35c44499fa21e2f9f57b63..1c2eb38f3c51a6dcc93148ca34b1a6a1de7aa465 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -659,7 +659,11 @@ static int raid10_mergeable_bvec(struct request_queue *q,
                max = biovec->bv_len;
 
        if (mddev->merge_check_needed) {
-               struct r10bio r10_bio;
+               struct {
+                       struct r10bio r10_bio;
+                       struct r10dev devs[conf->copies];
+               } on_stack;
+               struct r10bio *r10_bio = &on_stack.r10_bio;
                int s;
                if (conf->reshape_progress != MaxSector) {
                        /* Cannot give any guidance during reshape */
@@ -667,18 +671,18 @@ static int raid10_mergeable_bvec(struct request_queue *q,
                                return biovec->bv_len;
                        return 0;
                }
-               r10_bio.sector = sector;
-               raid10_find_phys(conf, &r10_bio);
+               r10_bio->sector = sector;
+               raid10_find_phys(conf, r10_bio);
                rcu_read_lock();
                for (s = 0; s < conf->copies; s++) {
-                       int disk = r10_bio.devs[s].devnum;
+                       int disk = r10_bio->devs[s].devnum;
                        struct md_rdev *rdev = rcu_dereference(
                                conf->mirrors[disk].rdev);
                        if (rdev && !test_bit(Faulty, &rdev->flags)) {
                                struct request_queue *q =
                                        bdev_get_queue(rdev->bdev);
                                if (q->merge_bvec_fn) {
-                                       bvm->bi_sector = r10_bio.devs[s].addr
+                                       bvm->bi_sector = r10_bio->devs[s].addr
                                                + rdev->data_offset;
                                        bvm->bi_bdev = rdev->bdev;
                                        max = min(max, q->merge_bvec_fn(
@@ -690,7 +694,7 @@ static int raid10_mergeable_bvec(struct request_queue *q,
                                struct request_queue *q =
                                        bdev_get_queue(rdev->bdev);
                                if (q->merge_bvec_fn) {
-                                       bvm->bi_sector = r10_bio.devs[s].addr
+                                       bvm->bi_sector = r10_bio->devs[s].addr
                                                + rdev->data_offset;
                                        bvm->bi_bdev = rdev->bdev;
                                        max = min(max, q->merge_bvec_fn(
@@ -2680,8 +2684,7 @@ static void raid10d(struct mddev *mddev)
        blk_start_plug(&plug);
        for (;;) {
 
-               if (atomic_read(&mddev->plug_cnt) == 0)
-                       flush_pending_writes(conf);
+               flush_pending_writes(conf);
 
                spin_lock_irqsave(&conf->device_lock, flags);
                if (list_empty(head)) {
@@ -4415,14 +4418,18 @@ static int handle_reshape_read_error(struct mddev *mddev,
 {
        /* Use sync reads to get the blocks from somewhere else */
        int sectors = r10_bio->sectors;
-       struct r10bio r10b;
        struct r10conf *conf = mddev->private;
+       struct {
+               struct r10bio r10_bio;
+               struct r10dev devs[conf->copies];
+       } on_stack;
+       struct r10bio *r10b = &on_stack.r10_bio;
        int slot = 0;
        int idx = 0;
        struct bio_vec *bvec = r10_bio->master_bio->bi_io_vec;
 
-       r10b.sector = r10_bio->sector;
-       __raid10_find_phys(&conf->prev, &r10b);
+       r10b->sector = r10_bio->sector;
+       __raid10_find_phys(&conf->prev, r10b);
 
        while (sectors) {
                int s = sectors;
@@ -4433,7 +4440,7 @@ static int handle_reshape_read_error(struct mddev *mddev,
                        s = PAGE_SIZE >> 9;
 
                while (!success) {
-                       int d = r10b.devs[slot].devnum;
+                       int d = r10b->devs[slot].devnum;
                        struct md_rdev *rdev = conf->mirrors[d].rdev;
                        sector_t addr;
                        if (rdev == NULL ||
@@ -4441,7 +4448,7 @@ static int handle_reshape_read_error(struct mddev *mddev,
                            !test_bit(In_sync, &rdev->flags))
                                goto failed;
 
-                       addr = r10b.devs[slot].addr + idx * PAGE_SIZE;
+                       addr = r10b->devs[slot].addr + idx * PAGE_SIZE;
                        success = sync_page_io(rdev,
                                               addr,
                                               s << 9,