linux-stable/drivers/md/raid1-10.c
Johannes Thumshirn 0c67dd6441 md: raid1: check if adding pages to resync bio fails
Check if adding pages to resync bio fails and if bail out.

As the comment above suggests this cannot happen, WARN if it actually
happens. Technically __bio_add_pages() would be sufficient here, but
asserting the pages actually get added to the bio is preferred.

This way we can mark bio_add_pages as __must_check.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/33aea4c271220dc9bcab58c4b7bec478c1511142.1685532726.git.johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-01 09:13:31 -06:00

112 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Maximum size of each resync request */
#define RESYNC_BLOCK_SIZE (64*1024)
#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
/*
* Number of guaranteed raid bios in case of extreme VM load:
*/
#define NR_RAID_BIOS 256
/* when we get a read error on a read-only array, we redirect to another
* device without failing the first device, or trying to over-write to
* correct the read error. To keep track of bad blocks on a per-bio
* level, we store IO_BLOCKED in the appropriate 'bios' pointer
*/
#define IO_BLOCKED ((struct bio *)1)
/* When we successfully write to a known bad-block, we need to remove the
* bad-block marking which must be done from process context. So we record
* the success by setting devs[n].bio to IO_MADE_GOOD
*/
#define IO_MADE_GOOD ((struct bio *)2)
#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
/* for managing resync I/O pages */
struct resync_pages {
void *raid_bio;
struct page *pages[RESYNC_PAGES];
};
struct raid1_plug_cb {
struct blk_plug_cb cb;
struct bio_list pending;
};
static void rbio_pool_free(void *rbio, void *data)
{
kfree(rbio);
}
static inline int resync_alloc_pages(struct resync_pages *rp,
gfp_t gfp_flags)
{
int i;
for (i = 0; i < RESYNC_PAGES; i++) {
rp->pages[i] = alloc_page(gfp_flags);
if (!rp->pages[i])
goto out_free;
}
return 0;
out_free:
while (--i >= 0)
put_page(rp->pages[i]);
return -ENOMEM;
}
static inline void resync_free_pages(struct resync_pages *rp)
{
int i;
for (i = 0; i < RESYNC_PAGES; i++)
put_page(rp->pages[i]);
}
static inline void resync_get_all_pages(struct resync_pages *rp)
{
int i;
for (i = 0; i < RESYNC_PAGES; i++)
get_page(rp->pages[i]);
}
static inline struct page *resync_fetch_page(struct resync_pages *rp,
unsigned idx)
{
if (WARN_ON_ONCE(idx >= RESYNC_PAGES))
return NULL;
return rp->pages[idx];
}
/*
* 'strct resync_pages' stores actual pages used for doing the resync
* IO, and it is per-bio, so make .bi_private points to it.
*/
static inline struct resync_pages *get_resync_pages(struct bio *bio)
{
return bio->bi_private;
}
/* generally called after bio_reset() for reseting bvec */
static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
int size)
{
int idx = 0;
/* initialize bvec table again */
do {
struct page *page = resync_fetch_page(rp, idx);
int len = min_t(int, size, PAGE_SIZE);
if (WARN_ON(!bio_add_page(bio, page, len, 0))) {
bio->bi_status = BLK_STS_RESOURCE;
bio_endio(bio);
return;
}
size -= len;
} while (idx++ < RESYNC_PAGES && size > 0);
}