linux - Contrib clone of linux

Age	Commit message (Expand)	Author
2011-10-31	dm log userspace: fix comment hyphens	Jonathan Brassow
2009-06-22	dm raid1: add userspace log	Jonthan Brassow

/* * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include <linux/highmem.h> /* this is some deeply nasty code. ctree.h has a different * definition for this BTRFS_SETGET_FUNCS macro, behind a #ifndef * * The end result is that anyone who #includes ctree.h gets a * declaration for the btrfs_set_foo functions and btrfs_foo functions * * This file declares the macros and then #includes ctree.h, which results * in cpp creating the function here based on the template below. * * These setget functions do all the extent_buffer related mapping * required to efficiently read and write specific fields in the extent * buffers. Every pointer to metadata items in btrfs is really just * an unsigned long offset into the extent buffer which has been * cast to a specific type. This gives us all the gcc type checking. * * The extent buffer api is used to do all the kmapping and page * spanning work required to get extent buffers in highmem and have * a metadata blocksize different from the page size. * * The macro starts with a simple function prototype declaration so that * sparse won't complain about it being static. */ #define BTRFS_SETGET_FUNCS(name, type, member, bits) \ u##bits btrfs_##name(struct extent_buffer *eb, type *s); \ void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val); \ u##bits btrfs_##name(struct extent_buffer *eb, \ type *s) \ { \ unsigned long part_offset = (unsigned long)s; \ unsigned long offset = part_offset + offsetof(type, member); \ type *p; \ /* ugly, but we want the fast path here */ \ if (eb->map_token && offset >= eb->map_start && \ offset + sizeof(((type *)0)->member) <= eb->map_start + \ eb->map_len) { \ p = (type *)(eb->kaddr + part_offset - eb->map_start); \ return le##bits##_to_cpu(p->member); \ } \ { \ int err; \ char *map_token; \ char *kaddr; \ int unmap_on_exit = (eb->map_token == NULL); \ unsigned long map_start; \ unsigned long map_len; \ u##bits res; \ err = map_extent_buffer(eb, offset, \ sizeof(((type *)0)->member), \ &map_token, &kaddr, \ &map_start, &map_len, KM_USER1); \ if (err) { \ __le##bits leres; \ read_eb_member(eb, s, type, member, &leres); \ return le##bits##_to_cpu(leres); \ } \ p = (type *)(kaddr + part_offset - map_start); \ res = le##bits##_to_cpu(p->member); \ if (unmap_on_exit) \ unmap_extent_buffer(eb, map_token, KM_USER1); \ return res; \ } \ } \ void btrfs_set_##name(struct extent_buffer *eb, \ type *s, u##bits val) \ { \ unsigned long part_offset = (unsigned long)s; \ unsigned long offset = part_offset + offsetof(type, member); \ type *p; \ /* ugly, but we want the fast path here */ \ if (eb->map_token && offset >= eb->map_start && \ offset + sizeof(((type *)0)->member) <= eb->map_start + \ eb->map_len) { \ p = (type *)(eb->kaddr + part_offset - eb->map_start); \ p->member = cpu_to_le##bits(val); \ return; \ } \ { \ int err; \ char *map_token; \ char *kaddr; \ int unmap_on_exit = (eb->map_token == NULL); \ unsigned long map_start; \ unsigned long map_len; \ err = map_extent_buffer(eb, offset, \ sizeof(((type *)0)->member), \ &map_token, &kaddr, \ &map_start, &map_len, KM_USER1); \ if (err) { \ __le##bits val2; \ val2 = cpu_to_le##bits(val); \ write_eb_member(eb, s, type, member, &val2); \ return; \ } \ p = (type *)(kaddr + part_offset - map_start); \ p->member = cpu_to_le##bits(val); \ if (unmap_on_exit) \ unmap_extent_buffer(eb, map_token, KM_USER1); \ } \ } #include "ctree.h" void btrfs_node_key(struct extent_buffer *eb, struct btrfs_disk_key *disk_key, int nr) { unsigned long ptr = btrfs_node_key_ptr_offset(nr); if (eb->map_token && ptr >= eb->map_start && ptr + sizeof(*disk_key) <= eb->map_start + eb->map_len) { memcpy(disk_key, eb->kaddr + ptr - eb->map_start, sizeof(*disk_key)); return; } else if (eb->map_token) { unmap_extent_buffer(eb, eb->map_token, KM_USER1); eb->map_token = NULL; } read_eb_member(eb, (struct btrfs_key_ptr *)ptr, struct btrfs_key_ptr, key, disk_key); }