diff options
-rw-r--r-- | sys/kern/uipc_cow.c | 6 | ||||
-rw-r--r-- | sys/vm/vm_page.c | 6 | ||||
-rw-r--r-- | sys/vm/vm_page.h | 8 |
3 files changed, 14 insertions, 6 deletions
diff --git a/sys/kern/uipc_cow.c b/sys/kern/uipc_cow.c index 2e29ee3..52988dd 100644 --- a/sys/kern/uipc_cow.c +++ b/sys/kern/uipc_cow.c @@ -129,7 +129,11 @@ socow_setup(struct mbuf *m0, struct uio *uio) * set up COW */ vm_page_lock_queues(); - vm_page_cowsetup(pp); + if (vm_page_cowsetup(pp) != 0) { + vm_page_unhold(pp); + vm_page_unlock_queues(); + return (0); + } /* * wire the page for I/O diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c index a4ac79b..8befdd5 100644 --- a/sys/vm/vm_page.c +++ b/sys/vm/vm_page.c @@ -106,6 +106,7 @@ __FBSDID("$FreeBSD$"); #include <sys/systm.h> #include <sys/lock.h> #include <sys/kernel.h> +#include <sys/limits.h> #include <sys/malloc.h> #include <sys/mutex.h> #include <sys/proc.h> @@ -2112,13 +2113,16 @@ vm_page_cowclear(vm_page_t m) */ } -void +int vm_page_cowsetup(vm_page_t m) { mtx_assert(&vm_page_queue_mtx, MA_OWNED); + if (m->cow == USHRT_MAX - 1) + return (EBUSY); m->cow++; pmap_remove_write(m); + return (0); } #include "opt_ddb.h" diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h index f609a21..7f996ea 100644 --- a/sys/vm/vm_page.h +++ b/sys/vm/vm_page.h @@ -111,12 +111,12 @@ struct vm_page { vm_paddr_t phys_addr; /* physical address of page */ struct md_page md; /* machine dependant stuff */ uint8_t queue; /* page queue index */ - int8_t segind; + int8_t segind; u_short flags; /* see below */ uint8_t order; /* index of the buddy queue */ uint8_t pool; - u_short wire_count; /* wired down maps refs (P) */ - u_int cow; /* page cow mapping count */ + u_short cow; /* page cow mapping count */ + u_int wire_count; /* wired down maps refs (P) */ short hold_count; /* page hold count */ u_short oflags; /* page flags (O) */ u_char act_count; /* page usage count */ @@ -336,7 +336,7 @@ void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); void vm_page_free_toq(vm_page_t m); void vm_page_zero_idle_wakeup(void); void vm_page_cowfault (vm_page_t); -void vm_page_cowsetup (vm_page_t); +int vm_page_cowsetup(vm_page_t); void vm_page_cowclear (vm_page_t); /* |