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 (at) 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
Indexes created Sun Sep 21 18:09:52 GMT 2025