Date: Wed, 24 Feb 2021 07:59:05 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 2947fc2ccf91 - stable/13 - lockf: ensure atomicity of lockf for open(O_CREAT|O_EXCL|O_EXLOCK) Message-ID: <202102240759.11O7x5e5046835@gitrepo.freebsd.org>
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The branch stable/13 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=2947fc2ccf918661b0896526a0c0513c59d8d652 commit 2947fc2ccf918661b0896526a0c0513c59d8d652 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2021-01-29 23:48:55 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2021-02-24 07:50:27 +0000 lockf: ensure atomicity of lockf for open(O_CREAT|O_EXCL|O_EXLOCK) (cherry picked from commit fa3bd463cee5c3abeac29a83dc86eb3abfa97b06) (cherry picked from commit 662283b1088d6488671b90ab18a66a997c526448) --- sys/kern/vfs_default.c | 15 +++++++++++++++ sys/kern/vfs_subr.c | 4 +++- sys/kern/vfs_vnops.c | 23 ++++++++++++++++++++--- sys/sys/fcntl.h | 1 + sys/sys/vnode.h | 2 ++ 5 files changed, 41 insertions(+), 4 deletions(-) diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c index 382fbb2d9ace..3c428d7b7511 100644 --- a/sys/kern/vfs_default.c +++ b/sys/kern/vfs_default.c @@ -423,10 +423,25 @@ int vop_stdadvlock(struct vop_advlock_args *ap) { struct vnode *vp; + struct mount *mp; struct vattr vattr; int error; vp = ap->a_vp; + + /* + * Provide atomicity of open(O_CREAT | O_EXCL | O_EXLOCK) for + * local filesystems. See vn_open_cred() for reciprocal part. + */ + mp = vp->v_mount; + if (mp != NULL && (mp->mnt_flag & MNT_LOCAL) != 0 && + ap->a_op == F_SETLK && (ap->a_flags & F_FIRSTOPEN) == 0) { + VI_LOCK(vp); + while ((vp->v_iflag & VI_FOPENING) != 0) + msleep(vp, VI_MTX(vp), PLOCK, "lockfo", 0); + VI_UNLOCK(vp); + } + if (ap->a_fl->l_whence == SEEK_END) { /* * The NFSv4 server must avoid doing a vn_lock() here, since it diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index 04cd0e0175f9..3e39d19666e5 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -4116,8 +4116,10 @@ vn_printf(struct vnode *vp, const char *fmt, ...) strlcat(buf, "|VI_OWEINACT", sizeof(buf)); if (vp->v_iflag & VI_DEFINACT) strlcat(buf, "|VI_DEFINACT", sizeof(buf)); + if (vp->v_iflag & VI_FOPENING) + strlcat(buf, "|VI_FOPENING", sizeof(buf)); flags = vp->v_iflag & ~(VI_TEXT_REF | VI_MOUNT | VI_DOINGINACT | - VI_OWEINACT | VI_DEFINACT); + VI_OWEINACT | VI_DEFINACT | VI_FOPENING); if (flags != 0) { snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); strlcat(buf, buf2, sizeof(buf)); diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c index 71dd379558cb..781968f2db53 100644 --- a/sys/kern/vfs_vnops.c +++ b/sys/kern/vfs_vnops.c @@ -228,8 +228,10 @@ vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, struct vattr vat; struct vattr *vap = &vat; int fmode, error; + bool first_open; restart: + first_open = false; fmode = *flagp; if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT | O_EXCL | O_DIRECTORY)) @@ -275,8 +277,16 @@ restart: #endif error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, &ndp->ni_cnd, vap); - VOP_VPUT_PAIR(ndp->ni_dvp, error == 0 ? &ndp->ni_vp : - NULL, false); + vp = ndp->ni_vp; + if (error == 0 && (fmode & O_EXCL) != 0 && + (fmode & (O_EXLOCK | O_SHLOCK)) != 0) { + VI_LOCK(vp); + vp->v_iflag |= VI_FOPENING; + VI_UNLOCK(vp); + first_open = true; + } + VOP_VPUT_PAIR(ndp->ni_dvp, error == 0 ? &vp : NULL, + false); vn_finished_write(mp); if (error) { NDFREE(ndp, NDF_ONLY_PNBUF); @@ -287,7 +297,6 @@ restart: return (error); } fmode &= ~O_TRUNC; - vp = ndp->ni_vp; } else { if (ndp->ni_dvp == ndp->ni_vp) vrele(ndp->ni_dvp); @@ -317,6 +326,12 @@ restart: vp = ndp->ni_vp; } error = vn_open_vnode(vp, fmode, cred, td, fp); + if (first_open) { + VI_LOCK(vp); + vp->v_iflag &= ~VI_FOPENING; + wakeup(vp); + VI_UNLOCK(vp); + } if (error) goto bad; *flagp = fmode; @@ -352,6 +367,8 @@ vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp) type = F_FLOCK; if ((fmode & FNONBLOCK) == 0) type |= F_WAIT; + if ((fmode & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) + type |= F_FIRSTOPEN; error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); if (error == 0) fp->f_flag |= FHASLOCK; diff --git a/sys/sys/fcntl.h b/sys/sys/fcntl.h index 3c29c04e46db..70e68246be13 100644 --- a/sys/sys/fcntl.h +++ b/sys/sys/fcntl.h @@ -287,6 +287,7 @@ typedef __pid_t pid_t; #define F_POSIX 0x040 /* Use POSIX semantics for lock */ #define F_REMOTE 0x080 /* Lock owner is remote NFS client */ #define F_NOINTR 0x100 /* Ignore signals when waiting */ +#define F_FIRSTOPEN 0x200 /* First right to advlock file */ #endif /* diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h index 639a16881e09..9d68f9e236f6 100644 --- a/sys/sys/vnode.h +++ b/sys/sys/vnode.h @@ -254,6 +254,8 @@ struct xvnode { #define VI_DOINGINACT 0x0004 /* VOP_INACTIVE is in progress */ #define VI_OWEINACT 0x0008 /* Need to call inactive */ #define VI_DEFINACT 0x0010 /* deferred inactive */ +#define VI_FOPENING 0x0020 /* In open, with opening process having the + first right to advlock file */ #define VV_ROOT 0x0001 /* root of its filesystem */ #define VV_ISTTY 0x0002 /* vnode represents a tty */
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