| 1 | /* $NetBSD: ext2fs_extents.c,v 1.3 2016/08/13 07:40:10 christos Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2010 Zheng Liu <lz@freebsd.org> |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 17 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 20 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 21 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 22 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 23 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 24 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 25 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 26 | * SUCH DAMAGE. |
| 27 | * |
| 28 | * $FreeBSD: head/sys/fs/ext2fs/ext2_extents.c 295523 2016-02-11 15:27:14Z pfg $ |
| 29 | */ |
| 30 | |
| 31 | #include <sys/cdefs.h> |
| 32 | __KERNEL_RCSID(0, "$NetBSD: ext2fs_extents.c,v 1.3 2016/08/13 07:40:10 christos Exp $" ); |
| 33 | |
| 34 | #include <sys/param.h> |
| 35 | #include <sys/systm.h> |
| 36 | #include <sys/resourcevar.h> |
| 37 | #include <sys/kernel.h> |
| 38 | #include <sys/file.h> |
| 39 | #include <sys/stat.h> |
| 40 | #include <sys/buf.h> |
| 41 | #include <sys/proc.h> |
| 42 | #include <sys/mount.h> |
| 43 | #include <sys/vnode.h> |
| 44 | #include <sys/signalvar.h> |
| 45 | #include <sys/kauth.h> |
| 46 | |
| 47 | #include <ufs/ufs/inode.h> |
| 48 | #include <ufs/ufs/ufsmount.h> |
| 49 | #include <ufs/ufs/ufs_extern.h> |
| 50 | |
| 51 | |
| 52 | #include <ufs/ext2fs/ext2fs.h> |
| 53 | #include <ufs/ext2fs/ext2fs_extents.h> |
| 54 | #include <ufs/ext2fs/ext2fs_extern.h> |
| 55 | |
| 56 | |
| 57 | |
| 58 | static bool |
| 59 | ext4_ext_binsearch_index(struct inode *ip, struct ext4_extent_path *path, |
| 60 | daddr_t lbn, daddr_t *first_lbn, daddr_t *last_lbn) |
| 61 | { |
| 62 | struct ext4_extent_header *ehp = path->ep_header; |
| 63 | struct ext4_extent_index *first, *last, *l, *r, *m; |
| 64 | |
| 65 | first = (struct ext4_extent_index *)(char *)(ehp + 1); |
| 66 | last = first + ehp->eh_ecount - 1; |
| 67 | l = first; |
| 68 | r = last; |
| 69 | while (l <= r) { |
| 70 | m = l + (r - l) / 2; |
| 71 | if (lbn < m->ei_blk) |
| 72 | r = m - 1; |
| 73 | else |
| 74 | l = m + 1; |
| 75 | } |
| 76 | |
| 77 | if (l == first) { |
| 78 | path->ep_sparse_ext.e_blk = *first_lbn; |
| 79 | path->ep_sparse_ext.e_len = first->ei_blk - *first_lbn; |
| 80 | path->ep_sparse_ext.e_start_hi = 0; |
| 81 | path->ep_sparse_ext.e_start_lo = 0; |
| 82 | path->ep_is_sparse = true; |
| 83 | return true; |
| 84 | } |
| 85 | path->ep_index = l - 1; |
| 86 | *first_lbn = path->ep_index->ei_blk; |
| 87 | if (path->ep_index < last) |
| 88 | *last_lbn = l->ei_blk - 1; |
| 89 | return false; |
| 90 | } |
| 91 | |
| 92 | static void |
| 93 | ext4_ext_binsearch(struct inode *ip, struct ext4_extent_path *path, daddr_t lbn, |
| 94 | daddr_t first_lbn, daddr_t last_lbn) |
| 95 | { |
| 96 | struct ext4_extent_header *ehp = path->ep_header; |
| 97 | struct ext4_extent *first, *l, *r, *m; |
| 98 | |
| 99 | if (ehp->eh_ecount == 0) |
| 100 | return; |
| 101 | |
| 102 | first = (struct ext4_extent *)(char *)(ehp + 1); |
| 103 | l = first; |
| 104 | r = first + ehp->eh_ecount - 1; |
| 105 | while (l <= r) { |
| 106 | m = l + (r - l) / 2; |
| 107 | if (lbn < m->e_blk) |
| 108 | r = m - 1; |
| 109 | else |
| 110 | l = m + 1; |
| 111 | } |
| 112 | |
| 113 | if (l == first) { |
| 114 | path->ep_sparse_ext.e_blk = first_lbn; |
| 115 | path->ep_sparse_ext.e_len = first->e_blk - first_lbn; |
| 116 | path->ep_sparse_ext.e_start_hi = 0; |
| 117 | path->ep_sparse_ext.e_start_lo = 0; |
| 118 | path->ep_is_sparse = true; |
| 119 | return; |
| 120 | } |
| 121 | path->ep_ext = l - 1; |
| 122 | if (path->ep_ext->e_blk + path->ep_ext->e_len <= lbn) { |
| 123 | path->ep_sparse_ext.e_blk = path->ep_ext->e_blk + |
| 124 | path->ep_ext->e_len; |
| 125 | if (l <= (first + ehp->eh_ecount - 1)) |
| 126 | path->ep_sparse_ext.e_len = l->e_blk - |
| 127 | path->ep_sparse_ext.e_blk; |
| 128 | else |
| 129 | path->ep_sparse_ext.e_len = last_lbn - |
| 130 | path->ep_sparse_ext.e_blk + 1; |
| 131 | path->ep_sparse_ext.e_start_hi = 0; |
| 132 | path->ep_sparse_ext.e_start_lo = 0; |
| 133 | path->ep_is_sparse = true; |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * Find a block in ext4 extent cache. |
| 139 | */ |
| 140 | int |
| 141 | ext4_ext_in_cache(struct inode *ip, daddr_t lbn, struct ext4_extent *ep) |
| 142 | { |
| 143 | struct ext4_extent_cache *ecp; |
| 144 | int ret = EXT4_EXT_CACHE_NO; |
| 145 | |
| 146 | ecp = &ip->inode_ext.e2fs.i_ext_cache; |
| 147 | |
| 148 | /* cache is invalid */ |
| 149 | if (ecp->ec_type == EXT4_EXT_CACHE_NO) |
| 150 | return ret; |
| 151 | |
| 152 | if (lbn >= ecp->ec_blk && lbn < ecp->ec_blk + ecp->ec_len) { |
| 153 | ep->e_blk = ecp->ec_blk; |
| 154 | ep->e_start_lo = ecp->ec_start & 0xffffffff; |
| 155 | ep->e_start_hi = ecp->ec_start >> 32 & 0xffff; |
| 156 | ep->e_len = ecp->ec_len; |
| 157 | ret = ecp->ec_type; |
| 158 | } |
| 159 | return ret; |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * Put an ext4_extent structure in ext4 cache. |
| 164 | */ |
| 165 | void |
| 166 | ext4_ext_put_cache(struct inode *ip, struct ext4_extent *ep, int type) |
| 167 | { |
| 168 | struct ext4_extent_cache *ecp; |
| 169 | |
| 170 | ecp = &ip->inode_ext.e2fs.i_ext_cache; |
| 171 | ecp->ec_type = type; |
| 172 | ecp->ec_blk = ep->e_blk; |
| 173 | ecp->ec_len = ep->e_len; |
| 174 | ecp->ec_start = (daddr_t)ep->e_start_hi << 32 | ep->e_start_lo; |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * Find an extent. |
| 179 | */ |
| 180 | struct ext4_extent_path * |
| 181 | ext4_ext_find_extent(struct m_ext2fs *fs, struct inode *ip, |
| 182 | daddr_t lbn, struct ext4_extent_path *path) |
| 183 | { |
| 184 | struct ext4_extent_header *ehp; |
| 185 | uint16_t i; |
| 186 | int error, size; |
| 187 | daddr_t nblk; |
| 188 | |
| 189 | ehp = (struct ext4_extent_header *)ip->i_din.e2fs_din->e2di_blocks; |
| 190 | |
| 191 | if (ehp->eh_magic != EXT4_EXT_MAGIC) |
| 192 | return NULL; |
| 193 | |
| 194 | path->ep_header = ehp; |
| 195 | |
| 196 | daddr_t first_lbn = 0; |
| 197 | daddr_t last_lbn = lblkno(ip->i_e2fs, ip->i_size); |
| 198 | |
| 199 | for (i = ehp->eh_depth; i != 0; --i) { |
| 200 | path->ep_depth = i; |
| 201 | path->ep_ext = NULL; |
| 202 | if (ext4_ext_binsearch_index(ip, path, lbn, &first_lbn, |
| 203 | &last_lbn)) { |
| 204 | return path; |
| 205 | } |
| 206 | |
| 207 | nblk = (daddr_t)path->ep_index->ei_leaf_hi << 32 | |
| 208 | path->ep_index->ei_leaf_lo; |
| 209 | size = blksize(fs, ip, nblk); |
| 210 | if (path->ep_bp != NULL) { |
| 211 | brelse(path->ep_bp, 0); |
| 212 | path->ep_bp = NULL; |
| 213 | } |
| 214 | error = bread(ip->i_devvp, fsbtodb(fs, nblk), size, 0, |
| 215 | &path->ep_bp); |
| 216 | if (error) { |
| 217 | brelse(path->ep_bp, 0); |
| 218 | path->ep_bp = NULL; |
| 219 | return NULL; |
| 220 | } |
| 221 | ehp = (struct ext4_extent_header *)path->ep_bp->b_data; |
| 222 | path->ep_header = ehp; |
| 223 | } |
| 224 | |
| 225 | path->ep_depth = i; |
| 226 | path->ep_ext = NULL; |
| 227 | path->ep_index = NULL; |
| 228 | path->ep_is_sparse = false; |
| 229 | |
| 230 | ext4_ext_binsearch(ip, path, lbn, first_lbn, last_lbn); |
| 231 | return path; |
| 232 | } |
| 233 | |