Author: kib Date: Tue Oct 22 16:09:25 2019 New Revision: 353890 URL: https://svnweb.freebsd.org/changeset/base/353890
Log: Add VV_VMSIZEVNLOCK flag. The flag specifies that vm_fault() handler should check the vnode' vm_object size under the vnode lock. It is converted into the object' OBJ_SIZEVNLOCK flag in vnode_pager_alloc(). Tested by: pho Reviewed by: markj Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Differential revision: https://reviews.freebsd.org/D21883 Modified: head/sys/sys/vnode.h head/sys/vm/vm_fault.c head/sys/vm/vm_object.h head/sys/vm/vnode_pager.c Modified: head/sys/sys/vnode.h ============================================================================== --- head/sys/sys/vnode.h Tue Oct 22 16:06:33 2019 (r353889) +++ head/sys/sys/vnode.h Tue Oct 22 16:09:25 2019 (r353890) @@ -247,6 +247,7 @@ struct xvnode { #define VV_NOSYNC 0x0004 /* unlinked, stop syncing */ #define VV_ETERNALDEV 0x0008 /* device that is never destroyed */ #define VV_CACHEDLABEL 0x0010 /* Vnode has valid cached MAC label */ +#define VV_VMSIZEVNLOCK 0x0020 /* object size check requires vnode lock */ #define VV_COPYONWRITE 0x0040 /* vnode is doing copy-on-write */ #define VV_SYSTEM 0x0080 /* vnode being used by kernel */ #define VV_PROCDEP 0x0100 /* vnode is process dependent */ Modified: head/sys/vm/vm_fault.c ============================================================================== --- head/sys/vm/vm_fault.c Tue Oct 22 16:06:33 2019 (r353889) +++ head/sys/vm/vm_fault.c Tue Oct 22 16:09:25 2019 (r353890) @@ -887,6 +887,13 @@ RetryFault_oom: */ if (fs.object->type != OBJT_DEFAULT || fs.object == fs.first_object) { + if ((fs.object->flags & OBJ_SIZEVNLOCK) != 0) { + rv = vm_fault_lock_vnode(&fs); + MPASS(rv == KERN_SUCCESS || + rv == KERN_RESOURCE_SHORTAGE); + if (rv == KERN_RESOURCE_SHORTAGE) + goto RetryFault; + } if (fs.pindex >= fs.object->size) { unlock_and_deallocate(&fs); return (KERN_OUT_OF_BOUNDS); Modified: head/sys/vm/vm_object.h ============================================================================== --- head/sys/vm/vm_object.h Tue Oct 22 16:06:33 2019 (r353889) +++ head/sys/vm/vm_object.h Tue Oct 22 16:09:25 2019 (r353890) @@ -186,6 +186,7 @@ struct vm_object { #define OBJ_DEAD 0x0008 /* dead objects (during rundown) */ #define OBJ_NOSPLIT 0x0010 /* dont split this object */ #define OBJ_UMTXDEAD 0x0020 /* umtx pshared was terminated */ +#define OBJ_SIZEVNLOCK 0x0040 /* lock vnode to check obj size */ #define OBJ_PG_DTOR 0x0080 /* dont reset object, leave that for dtor */ #define OBJ_MIGHTBEDIRTY 0x0100 /* object might be dirty, only for vnode */ #define OBJ_TMPFS_NODE 0x0200 /* object belongs to tmpfs VREG node */ Modified: head/sys/vm/vnode_pager.c ============================================================================== --- head/sys/vm/vnode_pager.c Tue Oct 22 16:06:33 2019 (r353889) +++ head/sys/vm/vnode_pager.c Tue Oct 22 16:09:25 2019 (r353890) @@ -269,8 +269,12 @@ retry: object->un_pager.vnp.vnp_size = size; object->un_pager.vnp.writemappings = 0; object->domain.dr_policy = vnode_domainset; - object->handle = handle; + if ((vp->v_vflag & VV_VMSIZEVNLOCK) != 0) { + VM_OBJECT_WLOCK(object); + vm_object_set_flag(object, OBJ_SIZEVNLOCK); + VM_OBJECT_WUNLOCK(object); + } VI_LOCK(vp); if (vp->v_object != NULL) { /* _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
