git: 5bd21cbbd1df - main - vfs: fix vfs_bio_clrbuf() for PAGE_SIZE > block size

The branch main has been updated by chs:

URL: https://cgit.FreeBSD.org/src/commit/?id=5bd21cbbd1df837ccc9fe7834f43636fd20d8792

commit 5bd21cbbd1df837ccc9fe7834f43636fd20d8792
Author:     Chuck Silvers <chs@FreeBSD.org>
AuthorDate: 2022-06-22 00:58:52 +0000
Commit:     Chuck Silvers <chs@FreeBSD.org>
CommitDate: 2022-06-22 00:58:52 +0000

    vfs: fix vfs_bio_clrbuf() for PAGE_SIZE > block size
    
    Calculate the desired page valid mask using math that will not
    overflow the types used.
    
    Sponsored by:   Netflix
    
    Reviewed by:    mckusick, kib, markj
    Differential Revision:  https://reviews.freebsd.org/D34837
---
 sys/kern/vfs_bio.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index 9082147b6034..7724e66f7bad 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -4852,7 +4852,8 @@ vfs_bio_set_valid(struct buf *bp, int base, int size)
 void
 vfs_bio_clrbuf(struct buf *bp) 
 {
-	int i, j, mask, sa, ea, slide;
+	int i, j, sa, ea, slide, zbits;
+	vm_page_bits_t mask;
 
 	if ((bp->b_flags & (B_VMIO | B_MALLOC)) != B_VMIO) {
 		clrbuf(bp);
@@ -4871,7 +4872,9 @@ vfs_bio_clrbuf(struct buf *bp)
 		if (bp->b_pages[i] == bogus_page)
 			continue;
 		j = sa / DEV_BSIZE;
-		mask = ((1 << ((ea - sa) / DEV_BSIZE)) - 1) << j;
+		zbits = (sizeof(vm_page_bits_t) * NBBY) -
+		    (ea - sa) / DEV_BSIZE;
+		mask = (VM_PAGE_BITS_ALL >> zbits) << j;
 		if ((bp->b_pages[i]->valid & mask) == mask)
 			continue;
 		if ((bp->b_pages[i]->valid & mask) == 0)