mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-12 09:58:36 +00:00
Code Issues Releases Activity

- Synchronize access to a page's valid field in vfs_bio_clrbuf()

Browse Source 
by using the lock from its containing object.
 - Remove GIANT_REQUIRED from vm_hold_load_pages().
This commit is contained in:
Alan Cox 2003-10-10 07:26:21 +00:00
parent 38b28673a3
commit 08814d66d5
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=120963
1 changed files with 10 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
sys/kern/vfs_bio.c
View File

@ -3512,19 +3512,19 @@ vfs_bio_clrbuf(struct buf *bp)
if ((bp->b_flags & (B_VMIO | B_MALLOC)) == B_VMIO) {
bp->b_flags &= ~B_INVAL;
bp->b_ioflags &= ~BIO_ERROR;
if (bp->b_object != NULL)
VM_OBJECT_LOCK(bp->b_object);
if( (bp->b_npages == 1) && (bp->b_bufsize < PAGE_SIZE) &&
(bp->b_offset & PAGE_MASK) == 0) {
mask = (1 << (bp->b_bufsize / DEV_BSIZE)) - 1;
if ((bp->b_pages[0]->valid & mask) == mask) {
bp->b_resid = 0;
return;
}
VM_OBJECT_LOCK_ASSERT(bp->b_pages[0]->object, MA_OWNED);
if ((bp->b_pages[0]->valid & mask) == mask)
goto unlock;
if (((bp->b_pages[0]->flags & PG_ZERO) == 0) &&
((bp->b_pages[0]->valid & mask) == 0)) {
bzero(bp->b_data, bp->b_bufsize);
bp->b_pages[0]->valid |= mask;
bp->b_resid = 0;
return;
goto unlock;
}
}
ea = sa = bp->b_data;
@ -3535,6 +3535,7 @@ vfs_bio_clrbuf(struct buf *bp)
(u_long)(vm_offset_t)ea,
(u_long)(vm_offset_t)bp->b_data + bp->b_bufsize);
mask = ((1 << ((ea - sa) / DEV_BSIZE)) - 1) << j;
VM_OBJECT_LOCK_ASSERT(bp->b_pages[i]->object, MA_OWNED);
if ((bp->b_pages[i]->valid & mask) == mask)
continue;
if ((bp->b_pages[i]->valid & mask) == 0) {
@ -3553,6 +3554,9 @@ vfs_bio_clrbuf(struct buf *bp)
vm_page_flag_clear(bp->b_pages[i], PG_ZERO);
vm_page_unlock_queues();
}
unlock:
if (bp->b_object != NULL)
VM_OBJECT_UNLOCK(bp->b_object);
bp->b_resid = 0;
} else {
clrbuf(bp);
@ -3571,8 +3575,6 @@ vm_hold_load_pages(struct buf * bp, vm_offset_t from, vm_offset_t to)
vm_page_t p;
int index;
GIANT_REQUIRED;
to = round_page(to);
from = round_page(from);
index = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT;