Re: Oops on 2.5.1-pre6 doing mkreiserfs on loop device

Jens Axboe
2001-12-07T15:01:33Z

On Fri, Dec 07 2001, Jens Axboe wrote:
> On Fri, Dec 07 2001, Jens Axboe wrote:
> > + bio_for_each_segment(bvec, bio, i) {
> > + org_vec = &bio_orig->bi_io_vec[0];
> ^
>
> argh, that should read 'i' and not '0' of course.

Updated patch follows.

--- /opt/kernel/linux-2.5.1-pre6/include/linux/bio.h Fri Dec 7 02:09:31 2001
+++ include/linux/bio.h Fri Dec 7 09:56:42 2001
@@ -100,7 +100,6 @@
#define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
#define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
#define bio_page(bio) bio_iovec((bio))->bv_page
-#define __bio_offset(bio, idx) bio_iovec_idx((bio), (idx))->bv_offset
#define bio_offset(bio) bio_iovec((bio))->bv_offset
#define bio_sectors(bio) ((bio)->bi_size >> 9)
#define bio_data(bio) (page_address(bio_page((bio))) + bio_offset((bio)))
@@ -136,10 +135,17 @@

#define bio_io_error(bio) bio_endio((bio), 0, bio_sectors((bio)))

-#define bio_for_each_segment(bvl, bio, i) \
- for (bvl = bio_iovec((bio)), i = (bio)->bi_idx; \
+/*
+ * drivers should not use the __ version unless they _really_ want to
+ * run through the entire bio and not just pending pieces
+ */
+#define __bio_for_each_segment(bvl, bio, i, start_idx) \
+ for (bvl = bio_iovec((bio)), i = (start_idx); \
i < (bio)->bi_vcnt; \
bvl++, i++)
+
+#define bio_for_each_segment(bvl, bio, i) \
+ __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)

/*
* get a reference to a bio, so it won't disappear. the intended use is
--- /opt/kernel/linux-2.5.1-pre6/mm/highmem.c Fri Dec 7 09:16:24 2001
+++ mm/highmem.c Fri Dec 7 09:57:05 2001
@@ -225,12 +225,11 @@

vfrom = page_address(fromvec->bv_page) + fromvec->bv_offset;

- __save_flags(flags);
- __cli();
+ local_irq_save(flags);
vto = kmap_atomic(tovec->bv_page, KM_BOUNCE_READ);
- memcpy(vto + tovec->bv_offset, vfrom, to->bi_size);
+ memcpy(vto + tovec->bv_offset, vfrom, tovec->bv_len);
kunmap_atomic(vto, KM_BOUNCE_READ);
- __restore_flags(flags);
+ local_irq_restore(flags);
}
}

@@ -263,28 +262,36 @@
static inline int bounce_end_io (struct bio *bio, int nr_sectors)
{
struct bio *bio_orig = bio->bi_private;
- struct page *page = bio_page(bio);
+ struct bio_vec *bvec, *org_vec;
unsigned long flags;
- int ret;
+ int ret, i;

if (test_bit(BIO_UPTODATE, &bio->bi_flags))
set_bit(BIO_UPTODATE, &bio_orig->bi_flags);

ret = bio_orig->bi_end_io(bio_orig, nr_sectors);

+ /*
+ * free up bounce indirect pages used
+ */
spin_lock_irqsave(&emergency_lock, flags);
- if (nr_emergency_pages >= POOL_SIZE) {
- spin_unlock_irqrestore(&emergency_lock, flags);
- __free_page(page);
- } else {
- /*
- * We are abusing page->list to manage
- * the highmem emergency pool:
- */
- list_add(&page->list, &emergency_pages);
- nr_emergency_pages++;
- spin_unlock_irqrestore(&emergency_lock, flags);
+ __bio_for_each_segment(bvec, bio, i, 0) {
+ org_vec = &bio_orig->bi_io_vec[i];
+ if (bvec->bv_page == org_vec->bv_page)
+ continue;
+
+ if (nr_emergency_pages >= POOL_SIZE)
+ __free_page(bvec->bv_page);
+ else {
+ /*
+ * We are abusing page->list to manage
+ * the highmem emergency pool:
+ */
+ list_add(&bvec->bv_page->list, &emergency_pages);
+ nr_emergency_pages++;
+ }
}
+ spin_unlock_irqrestore(&emergency_lock, flags);

bio_put(bio);
return ret;

--
Jens Axboe