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author | kib <kib@FreeBSD.org> | 2013-03-14 19:48:25 +0000 |
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committer | kib <kib@FreeBSD.org> | 2013-03-14 19:48:25 +0000 |
commit | 376c14488bc4e1c0b35d09dce966d5fcfae8a4c1 (patch) | |
tree | 84d418dff2b3767e4602e265530677e404e3dda6 | |
parent | 20173378f6418ff9af971e15450fcc901c720fbe (diff) | |
download | FreeBSD-src-376c14488bc4e1c0b35d09dce966d5fcfae8a4c1.zip FreeBSD-src-376c14488bc4e1c0b35d09dce966d5fcfae8a4c1.tar.gz |
Rewrite the vfs_bio_clrbuf(9) to not access the b_data for B_VMIO
buffers directly, use pmap_zero_page_area(9) for each zeroing page
region instead.
Sponsored by: The FreeBSD Foundation
Tested by: pho
MFC after: 2 weeks
-rw-r--r-- | sys/kern/vfs_bio.c | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c index 6d110ab..324efe5 100644 --- a/sys/kern/vfs_bio.c +++ b/sys/kern/vfs_bio.c @@ -3712,8 +3712,7 @@ vfs_bio_set_valid(struct buf *bp, int base, int size) void vfs_bio_clrbuf(struct buf *bp) { - int i, j, mask; - caddr_t sa, ea; + int i, j, mask, sa, ea, slide; if ((bp->b_flags & (B_VMIO | B_MALLOC)) != B_VMIO) { clrbuf(bp); @@ -3731,30 +3730,33 @@ vfs_bio_clrbuf(struct buf *bp) if ((bp->b_pages[0]->valid & mask) == mask) goto unlock; if ((bp->b_pages[0]->valid & mask) == 0) { - bzero(bp->b_data, bp->b_bufsize); + pmap_zero_page_area(bp->b_pages[0], 0, bp->b_bufsize); bp->b_pages[0]->valid |= mask; goto unlock; } } - ea = sa = bp->b_data; - for(i = 0; i < bp->b_npages; i++, sa = ea) { - ea = (caddr_t)trunc_page((vm_offset_t)sa + PAGE_SIZE); - ea = (caddr_t)(vm_offset_t)ulmin( - (u_long)(vm_offset_t)ea, - (u_long)(vm_offset_t)bp->b_data + bp->b_bufsize); + sa = bp->b_offset & PAGE_MASK; + slide = 0; + for (i = 0; i < bp->b_npages; i++, sa = 0) { + slide = imin(slide + PAGE_SIZE, bp->b_offset + bp->b_bufsize); + ea = slide & PAGE_MASK; + if (ea == 0) + ea = PAGE_SIZE; if (bp->b_pages[i] == bogus_page) continue; - j = ((vm_offset_t)sa & PAGE_MASK) / DEV_BSIZE; + j = sa / DEV_BSIZE; mask = ((1 << ((ea - sa) / DEV_BSIZE)) - 1) << j; VM_OBJECT_ASSERT_WLOCKED(bp->b_pages[i]->object); if ((bp->b_pages[i]->valid & mask) == mask) continue; if ((bp->b_pages[i]->valid & mask) == 0) - bzero(sa, ea - sa); + pmap_zero_page_area(bp->b_pages[i], sa, ea - sa); else { for (; sa < ea; sa += DEV_BSIZE, j++) { - if ((bp->b_pages[i]->valid & (1 << j)) == 0) - bzero(sa, DEV_BSIZE); + if ((bp->b_pages[i]->valid & (1 << j)) == 0) { + pmap_zero_page_area(bp->b_pages[i], + sa, DEV_BSIZE); + } } } bp->b_pages[i]->valid |= mask; |