Date: Thu, 22 Sep 2016 10:44:56 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r306176 - stable/10/sys/ufs/ufs Message-ID: <201609221044.u8MAiuAq054171@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: kib Date: Thu Sep 22 10:44:56 2016 New Revision: 306176 URL: https://svnweb.freebsd.org/changeset/base/306176 Log: MFC r305593: There is no need to upgrade the last dvp lock on lookups for modifying operations. Instead of upgrading, assert that the lock is exclusive. Explain the cause in comments. Modified: stable/10/sys/ufs/ufs/ufs_lookup.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/ufs/ufs/ufs_lookup.c ============================================================================== --- stable/10/sys/ufs/ufs/ufs_lookup.c Thu Sep 22 10:42:40 2016 (r306175) +++ stable/10/sys/ufs/ufs/ufs_lookup.c Thu Sep 22 10:44:56 2016 (r306176) @@ -76,32 +76,6 @@ SYSCTL_INT(_debug, OID_AUTO, dircheck, C /* true if old FS format...*/ #define OFSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0) -#ifdef QUOTA -static int -ufs_lookup_upgrade_lock(struct vnode *vp) -{ - int error; - - ASSERT_VOP_LOCKED(vp, __FUNCTION__); - if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE) - return (0); - - error = 0; - - /* - * Upgrade vnode lock, since getinoquota() - * requires exclusive lock to modify inode. - */ - vhold(vp); - vn_lock(vp, LK_UPGRADE | LK_RETRY); - VI_LOCK(vp); - if (vp->v_iflag & VI_DOOMED) - error = ENOENT; - vdropl(vp); - return (error); -} -#endif - static int ufs_delete_denied(struct vnode *vdp, struct vnode *tdp, struct ucred *cred, struct thread *td) @@ -259,12 +233,25 @@ ufs_lookup_ino(struct vnode *vdp, struct vnode_create_vobject(vdp, DIP(dp, i_size), cnp->cn_thread); bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; -#ifdef QUOTA - if ((nameiop == DELETE || nameiop == RENAME) && (flags & ISLASTCN)) { - error = ufs_lookup_upgrade_lock(vdp); - if (error != 0) - return (error); - } + +#ifdef DEBUG_VFS_LOCKS + /* + * Assert that the directory vnode is locked, and locked + * exclusively for the last component lookup for modifying + * operations. + * + * The directory-modifying operations need to save + * intermediate state in the inode between namei() call and + * actual directory manipulations. See fields in the struct + * inode marked as 'used during directory lookup'. We must + * ensure that upgrade in namei() does not happen, since + * upgrade might need to unlock vdp. If quotas are enabled, + * getinoquota() also requires exclusive lock to modify inode. + */ + ASSERT_VOP_LOCKED(vdp, "ufs_lookup1"); + if ((nameiop == CREATE || nameiop == DELETE || nameiop == RENAME) && + (flags & (LOCKPARENT | ISLASTCN)) == (LOCKPARENT | ISLASTCN)) + ASSERT_VOP_ELOCKED(vdp, "ufs_lookup2"); #endif restart:
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201609221044.u8MAiuAq054171>