Author: cperciva
Date: Mon Jan 11 20:38:39 2016
New Revision: 293698
URL: https://svnweb.freebsd.org/changeset/base/293698
Log:
Fix a bug introduced in r291716:
"The problem with the approach taken both in _bus_dmamap_load_pages and
bus_dmamap_load_ma_triv is that they split the request buffer into
arbitrary chunks based on page boundaries, creating segments that no
longer have a size that's a multiple of the sector size. This breaks
drivers like blkfront (and probably other stuff)." [1]
This was most easily triggered by running `fsck /` on a system running
in Xen (e.g. Amazon EC2) but also showed up via growfs(8) and probably
many other userland tools which access the disk directly.
Patch by: royger [1]
"Thinks this should be fine" by: ken
Modified:
head/sys/kern/subr_bus_dma.c
Modified: head/sys/kern/subr_bus_dma.c
==============================================================================
--- head/sys/kern/subr_bus_dma.c Mon Jan 11 20:27:05 2016
(r293697)
+++ head/sys/kern/subr_bus_dma.c Mon Jan 11 20:38:39 2016
(r293698)
@@ -131,28 +131,6 @@ _bus_dmamap_load_mbuf_sg(bus_dma_tag_t d
}
/*
- * Load tlen data starting at offset within a region specified by a list of
- * physical pages.
- */
-static int
-_bus_dmamap_load_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
- vm_page_t *pages, bus_size_t tlen, int offset, int *nsegs, int flags)
-{
- vm_paddr_t paddr;
- bus_size_t len;
- int error, i;
-
- for (i = 0, error = 0; error == 0 && tlen > 0; i++, tlen -= len) {
- len = min(PAGE_SIZE - offset, tlen);
- paddr = VM_PAGE_TO_PHYS(pages[i]) + offset;
- error = _bus_dmamap_load_phys(dmat, map, paddr, len,
- flags, NULL, nsegs);
- offset = 0;
- }
- return (error);
-}
-
-/*
* Load from block io.
*/
static int
@@ -168,8 +146,8 @@ _bus_dmamap_load_bio(bus_dma_tag_t dmat,
}
if ((bio->bio_flags & BIO_UNMAPPED) != 0)
- return (_bus_dmamap_load_pages(dmat, map, bio->bio_ma,
- bio->bio_bcount, bio->bio_ma_offset, nsegs, flags));
+ return (_bus_dmamap_load_ma(dmat, map, bio->bio_ma,
+ bio->bio_bcount, bio->bio_ma_offset, flags, NULL, nsegs));
return (_bus_dmamap_load_buffer(dmat, map, bio->bio_data,
bio->bio_bcount, kernel_pmap, flags, NULL, nsegs));
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
