Author: pjd Date: Wed Apr 28 18:29:48 2010 New Revision: 207334 URL: http://svn.freebsd.org/changeset/base/207334
Log: Backport fix for 'zfs_znode_dmu_init: existing znode for dbuf' panic from OpenSolaris. PR: kern/144402 Reported by: Alex Bakhtin <[email protected]> Tested by: Alex Bakhtin <[email protected]> Obtained from: OpenSolaris, Bug ID 6895088 MFC after: 3 days Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c Wed Apr 28 18:29:44 2010 (r207333) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c Wed Apr 28 18:29:48 2010 (r207334) @@ -704,6 +704,8 @@ zfs_mknode(znode_t *dzp, vattr_t *vap, d DMU_OT_ZNODE, sizeof (znode_phys_t) + bonuslen, tx); } } + + ZFS_OBJ_HOLD_ENTER(zfsvfs, obj); VERIFY(0 == dmu_bonus_hold(zfsvfs->z_os, obj, NULL, &db)); dmu_buf_will_dirty(db, tx); @@ -765,9 +767,7 @@ zfs_mknode(znode_t *dzp, vattr_t *vap, d pzp->zp_mode = MAKEIMODE(vap->va_type, vap->va_mode); if (!(flag & IS_ROOT_NODE)) { - ZFS_OBJ_HOLD_ENTER(zfsvfs, obj); *zpp = zfs_znode_alloc(zfsvfs, db, 0); - ZFS_OBJ_HOLD_EXIT(zfsvfs, obj); } else { /* * If we are creating the root node, the "parent" we @@ -776,6 +776,7 @@ zfs_mknode(znode_t *dzp, vattr_t *vap, d *zpp = dzp; } zfs_perm_init(*zpp, dzp, flag, vap, tx, cr, setaclp, fuidp); + ZFS_OBJ_HOLD_EXIT(zfsvfs, obj); if (!(flag & IS_ROOT_NODE)) { vnode_t *vp; @@ -939,19 +940,31 @@ again: /* * Not found create new znode/vnode + * but only if file exists. + * + * There is a small window where zfs_vget() could + * find this object while a file create is still in + * progress. Since a gen number can never be zero + * we will check that to determine if its an allocated + * file. */ - zp = zfs_znode_alloc(zfsvfs, db, doi.doi_data_block_size); - - vp = ZTOV(zp); - vp->v_vflag |= VV_FORCEINSMQ; - err = insmntque(vp, zfsvfs->z_vfs); - vp->v_vflag &= ~VV_FORCEINSMQ; - KASSERT(err == 0, ("insmntque() failed: error %d", err)); - VOP_UNLOCK(vp, 0); + if (((znode_phys_t *)db->db_data)->zp_gen != 0) { + zp = zfs_znode_alloc(zfsvfs, db, doi.doi_data_block_size); + *zpp = zp; + vp = ZTOV(zp); + vp->v_vflag |= VV_FORCEINSMQ; + err = insmntque(vp, zfsvfs->z_vfs); + vp->v_vflag &= ~VV_FORCEINSMQ; + KASSERT(err == 0, ("insmntque() failed: error %d", err)); + VOP_UNLOCK(vp, 0); + err = 0; + } else { + dmu_buf_rele(db, NULL); + err = ENOENT; + } ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num); - *zpp = zp; - return (0); + return (err); } int @@ -1440,6 +1453,7 @@ zfs_create_fs(objset_t *os, cred_t *cr, uint64_t norm = 0; nvpair_t *elem; int error; + int i; znode_t *rootzp = NULL; vnode_t vnode; vattr_t vattr; @@ -1537,6 +1551,9 @@ zfs_create_fs(objset_t *os, cred_t *cr, list_create(&zfsvfs.z_all_znodes, sizeof (znode_t), offsetof(znode_t, z_link_node)); + for (i = 0; i != ZFS_OBJ_MTX_SZ; i++) + mutex_init(&zfsvfs.z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL); + ASSERT(!POINTER_IS_VALID(rootzp->z_zfsvfs)); rootzp->z_zfsvfs = &zfsvfs; zfs_mknode(rootzp, &vattr, tx, cr, IS_ROOT_NODE, &zp, 0, NULL, NULL); @@ -1547,6 +1564,8 @@ zfs_create_fs(objset_t *os, cred_t *cr, dmu_buf_rele(rootzp->z_dbuf, NULL); rootzp->z_dbuf = NULL; + for (i = 0; i != ZFS_OBJ_MTX_SZ; i++) + mutex_destroy(&zfsvfs.z_hold_mtx[i]); mutex_destroy(&zfsvfs.z_znodes_lock); rootzp->z_vnode = NULL; kmem_cache_free(znode_cache, rootzp); _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
