Date: Thu, 9 Feb 2017 23:35:57 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r313495 - head/sys/kern Message-ID: <201702092335.v19NZvSQ026869@repo.freebsd.org>
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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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