Date: Sun, 25 Nov 2012 15:01:12 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r243518 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs Message-ID: <201211251501.qAPF1CKS079555@svn.freebsd.org>
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Author: avg Date: Sun Nov 25 15:01:12 2012 New Revision: 243518 URL: http://svnweb.freebsd.org/changeset/base/243518 Log: add zfs_bmap to aid vnode_pager_haspage ... otherwise zfs_getpages would mostly be called with one page at a time. It is expected that ZFS VOP_BMAP is only called from vnode_pager_haspage. Since ZFS files can have variable block sizes and also because we don't really know if any given blocks are consecutive, we can not really report any additional blocks behind or ahead of a given block. Since physical block numbers do not make sense for ZFS, we do not do any real translation and thus pass back blk = lblk. The net effect is that vnode_pager_haspage knows that the block exists and that the pages backed by the block can be accessed. vnode_pager_haspage may be wrong about the exact count of the pages backed by the block, because of a variable block size, which vnode_pager_haspage doesn't really know - it only knows max block size in a filesystem. So pages from multiple blocks can be passed to zfs_getpages, but that is expected and correctly handled. vnode_pager should not call zfs_bmap for any other reason, because ZFS implements VOP_PUTPAGES and thus vnode_pager_generic_getpages is not used. vfs_cluster code vfs_bio code should not be called for ZFS, because ZFS does not use buffer cache layer. Also, ZFS does not use vn_bmap_seekhole, it has its prviate mechanism for working with holes. The above list should cover all the current calls to VOP_BMAP. Reviewed by: kib MFC after: 6 weeks Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Sun Nov 25 14:53:26 2012 (r243517) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Sun Nov 25 15:01:12 2012 (r243518) @@ -5702,6 +5702,30 @@ zfs_freebsd_getpages(ap) } static int +zfs_freebsd_bmap(ap) + struct vop_bmap_args /* { + struct vnode *a_vp; + daddr_t a_bn; + struct bufobj **a_bop; + daddr_t *a_bnp; + int *a_runp; + int *a_runb; + } */ *ap; +{ + + if (ap->a_bop != NULL) + *ap->a_bop = &ap->a_vp->v_bufobj; + if (ap->a_bnp != NULL) + *ap->a_bnp = ap->a_bn; + if (ap->a_runp != NULL) + *ap->a_runp = 0; + if (ap->a_runb != NULL) + *ap->a_runb = 0; + + return (0); +} + +static int zfs_freebsd_open(ap) struct vop_open_args /* { struct vnode *a_vp; @@ -6806,7 +6830,7 @@ struct vop_vector zfs_vnodeops = { .vop_remove = zfs_freebsd_remove, .vop_rename = zfs_freebsd_rename, .vop_pathconf = zfs_freebsd_pathconf, - .vop_bmap = VOP_EOPNOTSUPP, + .vop_bmap = zfs_freebsd_bmap, .vop_fid = zfs_freebsd_fid, .vop_getextattr = zfs_getextattr, .vop_deleteextattr = zfs_deleteextattr,
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