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 struct ext4_extent_header *ehp = path->ep_header; 50 struct ext4_extent_index *first, *last, *l, *r, *m; 51 52 first = (struct ext4_extent_index *)(char *)(ehp + 1); 53 last = first + ehp->eh_ecount - 1; 54 l = first; 55 r = last; 56 while (l <= r) { 57 m = l + (r - l) / 2; 58 if (lbn < m->ei_blk) 59 r = m - 1; 60 else 61 l = m + 1; 62 } 63 64 if (l == first) { 65 path->ep_sparse_ext.e_blk = *first_lbn; 66 path->ep_sparse_ext.e_len = first->ei_blk - *first_lbn; 67 path->ep_sparse_ext.e_start_hi = 0; 68 path->ep_sparse_ext.e_start_lo = 0; 69 path->ep_is_sparse = true; 70 return (true); 71 } 72 path->ep_index = l - 1; 73 *first_lbn = path->ep_index->ei_blk; 74 if (path->ep_index < last) 75 *last_lbn = l->ei_blk - 1; 76 return (false); 77 } 78 79 static void 80 ext4_ext_binsearch(struct inode *ip, struct ext4_extent_path *path, daddr_t lbn, 81 daddr_t first_lbn, daddr_t last_lbn) 82 { 83 struct ext4_extent_header *ehp = path->ep_header; 84 struct ext4_extent *first, *l, *r, *m; 85 86 if (ehp->eh_ecount == 0) 87 return; 88 89 first = (struct ext4_extent *)(char *)(ehp + 1); 90 l = first; 91 r = first + ehp->eh_ecount - 1; 92 while (l <= r) { 93 m = l + (r - l) / 2; 94 if (lbn < m->e_blk) 95 r = m - 1; 96 else 97 l = m + 1; 98 } 99 100 if (l == first) { 101 path->ep_sparse_ext.e_blk = first_lbn; 102 path->ep_sparse_ext.e_len = first->e_blk - first_lbn; 103 path->ep_sparse_ext.e_start_hi = 0; 104 path->ep_sparse_ext.e_start_lo = 0; 105 path->ep_is_sparse = true; 106 return; 107 } 108 path->ep_ext = l - 1; 109 if (path->ep_ext->e_blk + path->ep_ext->e_len <= lbn) { 110 path->ep_sparse_ext.e_blk = path->ep_ext->e_blk + 111 path->ep_ext->e_len; 112 if (l <= (first + ehp->eh_ecount - 1)) 113 path->ep_sparse_ext.e_len = l->e_blk - 114 path->ep_sparse_ext.e_blk; 115 else 116 path->ep_sparse_ext.e_len = last_lbn - 117 path->ep_sparse_ext.e_blk + 1; 118 path->ep_sparse_ext.e_start_hi = 0; 119 path->ep_sparse_ext.e_start_lo = 0; 120 path->ep_is_sparse = true; 121 } 122 } 123 124 /* 125 * Find a block in ext4 extent cache. 126 */ 127 int 128 ext4_ext_in_cache(struct inode *ip, daddr_t lbn, struct ext4_extent *ep) 129 { 130 struct ext4_extent_cache *ecp; 131 int ret = EXT4_EXT_CACHE_NO; 132 133 ecp = &ip->i_ext_cache; 134 135 /* cache is invalid */ 136 if (ecp->ec_type == EXT4_EXT_CACHE_NO) 137 return (ret); 138 139 if (lbn >= ecp->ec_blk && lbn < ecp->ec_blk + ecp->ec_len) { 140 ep->e_blk = ecp->ec_blk; 141 ep->e_start_lo = ecp->ec_start & 0xffffffff; 142 ep->e_start_hi = ecp->ec_start >> 32 & 0xffff; 143 ep->e_len = ecp->ec_len; 144 ret = ecp->ec_type; 145 } 146 return (ret); 147 } 148 149 /* 150 * Put an ext4_extent structure in ext4 cache. 151 */ 152 void 153 ext4_ext_put_cache(struct inode *ip, struct ext4_extent *ep, int type) 154 { 155 struct ext4_extent_cache *ecp; 156 157 ecp = &ip->i_ext_cache; 158 ecp->ec_type = type; 159 ecp->ec_blk = ep->e_blk; 160 ecp->ec_len = ep->e_len; 161 ecp->ec_start = (daddr_t)ep->e_start_hi << 32 | ep->e_start_lo; 162 } 163 164 /* 165 * Find an extent. 166 */ 167 struct ext4_extent_path * 168 ext4_ext_find_extent(struct m_ext2fs *fs, struct inode *ip, 169 daddr_t lbn, struct ext4_extent_path *path) 170 { 171 struct ext4_extent_header *ehp; 172 uint16_t i; 173 int error, size; 174 daddr_t nblk; 175 176 ehp = (struct ext4_extent_header *)(char *)ip->i_db; 177 178 if (ehp->eh_magic != EXT4_EXT_MAGIC) 179 return (NULL); 180 181 path->ep_header = ehp; 182 183 daddr_t first_lbn = 0; 184 daddr_t last_lbn = lblkno(ip->i_e2fs, ip->i_size); 185 186 for (i = ehp->eh_depth; i != 0; --i) { 187 path->ep_depth = i; 188 path->ep_ext = NULL; 189 if (ext4_ext_binsearch_index(ip, path, lbn, &first_lbn, 190 &last_lbn)) { 191 return (path); 192 } 193 194 nblk = (daddr_t)path->ep_index->ei_leaf_hi << 32 | 195 path->ep_index->ei_leaf_lo; 196 size = blksize(fs, ip, nblk); 197 if (path->ep_bp != NULL) { 198 brelse(path->ep_bp); 199 path->ep_bp = NULL; 200 } 201 error = bread(ip->i_devvp, fsbtodb(fs, nblk), size, NOCRED, 202 &path->ep_bp); 203 if (error) { 204 brelse(path->ep_bp); 205 path->ep_bp = NULL; 206 return (NULL); 207 } 208 ehp = (struct ext4_extent_header *)path->ep_bp->b_data; 209 path->ep_header = ehp; 210 } 211 212 path->ep_depth = i; 213 path->ep_ext = NULL; 214 path->ep_index = NULL; 215 path->ep_is_sparse = false; 216 217 ext4_ext_binsearch(ip, path, lbn, first_lbn, last_lbn); 218 return (path); 219 } 220