1 /*- 2 * Copyright (c) 2010 Zheng Liu <lz@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/types.h> 32 #include <sys/kernel.h> 33 #include <sys/malloc.h> 34 #include <sys/vnode.h> 35 #include <sys/bio.h> 36 #include <sys/buf.h> 37 #include <sys/conf.h> 38 39 #include <fs/ext2fs/ext2_mount.h> 40 #include <fs/ext2fs/fs.h> 41 #include <fs/ext2fs/inode.h> 42 #include <fs/ext2fs/ext2fs.h> 43 #include <fs/ext2fs/ext2_extents.h> 44 #include <fs/ext2fs/ext2_extern.h> 45 46 static bool 47 ext4_ext_binsearch_index(struct inode *ip, struct ext4_extent_path *path, 48 daddr_t lbn, daddr_t *first_lbn, daddr_t *last_lbn) 49 { 50 struct ext4_extent_header *ehp = path->ep_header; 51 struct ext4_extent_index *first, *last, *l, *r, *m; 52 53 first = (struct ext4_extent_index *)(char *)(ehp + 1); 54 last = first + ehp->eh_ecount - 1; 55 l = first; 56 r = last; 57 while (l <= r) { 58 m = l + (r - l) / 2; 59 if (lbn < m->ei_blk) 60 r = m - 1; 61 else 62 l = m + 1; 63 } 64 65 if (l == first) { 66 path->ep_sparse_ext.e_blk = *first_lbn; 67 path->ep_sparse_ext.e_len = first->ei_blk - *first_lbn; 68 path->ep_sparse_ext.e_start_hi = 0; 69 path->ep_sparse_ext.e_start_lo = 0; 70 path->ep_is_sparse = true; 71 return (true); 72 } 73 path->ep_index = l - 1; 74 *first_lbn = path->ep_index->ei_blk; 75 if (path->ep_index < last) 76 *last_lbn = l->ei_blk - 1; 77 return (false); 78 } 79 80 static void 81 ext4_ext_binsearch(struct inode *ip, struct ext4_extent_path *path, daddr_t lbn, 82 daddr_t first_lbn, daddr_t last_lbn) 83 { 84 struct ext4_extent_header *ehp = path->ep_header; 85 struct ext4_extent *first, *l, *r, *m; 86 87 if (ehp->eh_ecount == 0) 88 return; 89 90 first = (struct ext4_extent *)(char *)(ehp + 1); 91 l = first; 92 r = first + ehp->eh_ecount - 1; 93 while (l <= r) { 94 m = l + (r - l) / 2; 95 if (lbn < m->e_blk) 96 r = m - 1; 97 else 98 l = m + 1; 99 } 100 101 if (l == first) { 102 path->ep_sparse_ext.e_blk = first_lbn; 103 path->ep_sparse_ext.e_len = first->e_blk - first_lbn; 104 path->ep_sparse_ext.e_start_hi = 0; 105 path->ep_sparse_ext.e_start_lo = 0; 106 path->ep_is_sparse = true; 107 return; 108 } 109 path->ep_ext = l - 1; 110 if (path->ep_ext->e_blk + path->ep_ext->e_len <= lbn) { 111 path->ep_sparse_ext.e_blk = path->ep_ext->e_blk + 112 path->ep_ext->e_len; 113 if (l <= (first + ehp->eh_ecount - 1)) 114 path->ep_sparse_ext.e_len = l->e_blk - 115 path->ep_sparse_ext.e_blk; 116 else 117 path->ep_sparse_ext.e_len = last_lbn - 118 path->ep_sparse_ext.e_blk + 1; 119 path->ep_sparse_ext.e_start_hi = 0; 120 path->ep_sparse_ext.e_start_lo = 0; 121 path->ep_is_sparse = true; 122 } 123 } 124 125 /* 126 * Find a block in ext4 extent cache. 127 */ 128 int 129 ext4_ext_in_cache(struct inode *ip, daddr_t lbn, struct ext4_extent *ep) 130 { 131 struct ext4_extent_cache *ecp; 132 int ret = EXT4_EXT_CACHE_NO; 133 134 ecp = &ip->i_ext_cache; 135 136 /* cache is invalid */ 137 if (ecp->ec_type == EXT4_EXT_CACHE_NO) 138 return (ret); 139 140 if (lbn >= ecp->ec_blk && lbn < ecp->ec_blk + ecp->ec_len) { 141 ep->e_blk = ecp->ec_blk; 142 ep->e_start_lo = ecp->ec_start & 0xffffffff; 143 ep->e_start_hi = ecp->ec_start >> 32 & 0xffff; 144 ep->e_len = ecp->ec_len; 145 ret = ecp->ec_type; 146 } 147 return (ret); 148 } 149 150 /* 151 * Put an ext4_extent structure in ext4 cache. 152 */ 153 void 154 ext4_ext_put_cache(struct inode *ip, struct ext4_extent *ep, int type) 155 { 156 struct ext4_extent_cache *ecp; 157 158 ecp = &ip->i_ext_cache; 159 ecp->ec_type = type; 160 ecp->ec_blk = ep->e_blk; 161 ecp->ec_len = ep->e_len; 162 ecp->ec_start = (daddr_t)ep->e_start_hi << 32 | ep->e_start_lo; 163 } 164 165 /* 166 * Find an extent. 167 */ 168 struct ext4_extent_path * 169 ext4_ext_find_extent(struct m_ext2fs *fs, struct inode *ip, 170 daddr_t lbn, struct ext4_extent_path *path) 171 { 172 struct ext4_extent_header *ehp; 173 uint16_t i; 174 int error, size; 175 daddr_t nblk; 176 177 ehp = (struct ext4_extent_header *)(char *)ip->i_db; 178 179 if (ehp->eh_magic != EXT4_EXT_MAGIC) 180 return (NULL); 181 182 path->ep_header = ehp; 183 184 daddr_t first_lbn = 0; 185 daddr_t last_lbn = lblkno(ip->i_e2fs, ip->i_size); 186 187 for (i = ehp->eh_depth; i != 0; --i) { 188 path->ep_depth = i; 189 path->ep_ext = NULL; 190 if (ext4_ext_binsearch_index(ip, path, lbn, &first_lbn, 191 &last_lbn)) { 192 return (path); 193 } 194 195 nblk = (daddr_t)path->ep_index->ei_leaf_hi << 32 | 196 path->ep_index->ei_leaf_lo; 197 size = blksize(fs, ip, nblk); 198 if (path->ep_bp != NULL) { 199 brelse(path->ep_bp); 200 path->ep_bp = NULL; 201 } 202 error = bread(ip->i_devvp, fsbtodb(fs, nblk), size, NOCRED, 203 &path->ep_bp); 204 if (error) { 205 brelse(path->ep_bp); 206 path->ep_bp = NULL; 207 return (NULL); 208 } 209 ehp = (struct ext4_extent_header *)path->ep_bp->b_data; 210 path->ep_header = ehp; 211 } 212 213 path->ep_depth = i; 214 path->ep_ext = NULL; 215 path->ep_index = NULL; 216 path->ep_is_sparse = false; 217 218 ext4_ext_binsearch(ip, path, lbn, first_lbn, last_lbn); 219 return (path); 220 } 221