Author: kib
Date: Thu Feb 9 23:35:57 2017
New Revision: 313495
URL: https://svnweb.freebsd.org/changeset/base/313495
Log:
Do not establish advisory locks when doing open(O_EXLOCK) or open(O_SHLOCK)
for files which do not have DTYPE_VNODE type.
Both flock(2) and fcntl(2) syscalls refuse to acquire advisory lock on
a file which type is not DTYPE_VNODE. Do the same when lock is
requested from open(2).
Restructure the block in vn_open_vnode() which handles O_EXLOCK and
O_SHLOCK open flags to make it easier to quit its execution earlier
with an error.
Tested by: pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Modified:
head/sys/kern/vfs_vnops.c
Modified: head/sys/kern/vfs_vnops.c
==============================================================================
--- head/sys/kern/vfs_vnops.c Thu Feb 9 23:33:06 2017 (r313494)
+++ head/sys/kern/vfs_vnops.c Thu Feb 9 23:35:57 2017 (r313495)
@@ -349,8 +349,12 @@ vn_open_vnode(struct vnode *vp, int fmod
if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0)
return (error);
- if (fmode & (O_EXLOCK | O_SHLOCK)) {
+ while ((fmode & (O_EXLOCK | O_SHLOCK)) != 0) {
KASSERT(fp != NULL, ("open with flock requires fp"));
+ if (fp->f_type != DTYPE_VNODE) {
+ error = EBADF;
+ break;
+ }
lock_flags = VOP_ISLOCKED(vp);
VOP_UNLOCK(vp, 0);
lf.l_whence = SEEK_SET;
@@ -367,8 +371,12 @@ vn_open_vnode(struct vnode *vp, int fmod
if (error == 0)
fp->f_flag |= FHASLOCK;
vn_lock(vp, lock_flags | LK_RETRY);
- if (error == 0 && vp->v_iflag & VI_DOOMED)
+ if (error != 0)
+ break;
+ if ((vp->v_iflag & VI_DOOMED) != 0) {
error = ENOENT;
+ break;
+ }
/*
* Another thread might have used this vnode as an
@@ -376,20 +384,20 @@ vn_open_vnode(struct vnode *vp, int fmod
* Ensure the vnode is still able to be opened for
* writing after the lock has been obtained.
*/
- if (error == 0 && accmode & VWRITE)
+ if ((accmode & VWRITE) != 0)
error = vn_writechk(vp);
+ break;
+ }
- if (error != 0) {
- fp->f_flag |= FOPENFAILED;
- fp->f_vnode = vp;
- if (fp->f_ops == &badfileops) {
- fp->f_type = DTYPE_VNODE;
- fp->f_ops = &vnops;
- }
- vref(vp);
+ if (error != 0) {
+ fp->f_flag |= FOPENFAILED;
+ fp->f_vnode = vp;
+ if (fp->f_ops == &badfileops) {
+ fp->f_type = DTYPE_VNODE;
+ fp->f_ops = &vnops;
}
- }
- if (error == 0 && fmode & FWRITE) {
+ vref(vp);
+ } else if ((fmode & FWRITE) != 0) {
VOP_ADD_WRITECOUNT(vp, 1);
CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
__func__, vp, vp->v_writecount);
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