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Add vm locking to sendfile(2) and sf_buf_free().

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Reported by:	Tamiji Homma <thomma@BayNetworks.com>
Tested by:	Tamiji Homma <thomma@BayNetworks.com>
This commit is contained in:
jhb 2001-05-25 19:23:04 +00:00
parent f19ccd9f40
commit e1ee9e1e41
1 changed files with 13 additions and 5 deletions
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18
sys/kern/uipc_syscalls.c
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@ -1487,12 +1487,11 @@ sf_buf_free(caddr_t addr, void *args)
{
struct sf_buf *sf;
struct vm_page *m;
int s;
sf = dtosf(addr);
mtx_lock(&vm_mtx);
pmap_qremove((vm_offset_t)addr, 1);
m = sf->m;
s = splvm();
vm_page_unwire(m, 0);
/*
* Check for the object going away on us. This can
@ -1501,7 +1500,7 @@ sf_buf_free(caddr_t addr, void *args)
*/
if (m->wire_count == 0 && m->object == NULL)
vm_page_free(m);
splx(s);
mtx_unlock(&vm_mtx);
sf->m = NULL;
mtx_lock(&sf_freelist.sf_lock);
SLIST_INSERT_HEAD(&sf_freelist.sf_head, sf, free_list);
@ -1646,16 +1645,19 @@ sendfile(struct proc *p, struct sendfile_args *uap)
*
* Wait and loop if busy.
*/
mtx_lock(&vm_mtx);
pg = vm_page_lookup(obj, pindex);
if (pg == NULL) {
pg = vm_page_alloc(obj, pindex, VM_ALLOC_NORMAL);
if (pg == NULL) {
VM_WAIT;
mtx_unlock(&vm_mtx);
goto retry_lookup;
}
vm_page_wakeup(pg);
} else if (vm_page_sleep_busy(pg, TRUE, "sfpbsy")) {
mtx_unlock(&vm_mtx);
goto retry_lookup;
}
@ -1680,6 +1682,7 @@ sendfile(struct proc *p, struct sendfile_args *uap)
* completes.
*/
vm_page_io_start(pg);
mtx_unlock(&vm_mtx);
/*
* Get the page from backing store.
@ -1698,6 +1701,7 @@ sendfile(struct proc *p, struct sendfile_args *uap)
error = VOP_READ(vp, &auio, IO_VMIO | ((MAXBSIZE / bsize) << 16),
p->p_ucred);
VOP_UNLOCK(vp, 0, p);
mtx_lock(&vm_mtx);
vm_page_flag_clear(pg, PG_ZERO);
vm_page_io_finish(pg);
if (error) {
@ -1712,6 +1716,7 @@ sendfile(struct proc *p, struct sendfile_args *uap)
vm_page_busy(pg);
vm_page_free(pg);
}
mtx_unlock(&vm_mtx);
sbunlock(&so->so_snd);
goto done;
}
@ -1722,12 +1727,13 @@ sendfile(struct proc *p, struct sendfile_args *uap)
* Get a sendfile buf. We usually wait as long as necessary,
* but this wait can be interrupted.
*/
mtx_unlock(&vm_mtx);
if ((sf = sf_buf_alloc()) == NULL) {
s = splvm();
mtx_lock(&vm_mtx);
vm_page_unwire(pg, 0);
if (pg->wire_count == 0 && pg->object == NULL)
vm_page_free(pg);
splx(s);
mtx_unlock(&vm_mtx);
sbunlock(&so->so_snd);
error = EINTR;
goto done;
@ -1737,8 +1743,10 @@ sendfile(struct proc *p, struct sendfile_args *uap)
* Allocate a kernel virtual page and insert the physical page
* into it.
*/
mtx_lock(&vm_mtx);
sf->m = pg;
pmap_qenter(sf->kva, &pg, 1);
mtx_unlock(&vm_mtx);
/*
* Get an mbuf header and set it up as having external storage.
*/