/* $NetBSD: ext2fs_extents.c,v 1.3 2016/08/13 07:40:10 christos Exp $ */ /*- * Copyright (c) 2010 Zheng Liu * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: head/sys/fs/ext2fs/ext2_extents.c 295523 2016-02-11 15:27:14Z pfg $ */ #include __KERNEL_RCSID(0, "$NetBSD: ext2fs_extents.c,v 1.3 2016/08/13 07:40:10 christos Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static bool ext4_ext_binsearch_index(struct inode *ip, struct ext4_extent_path *path, daddr_t lbn, daddr_t *first_lbn, daddr_t *last_lbn) { struct ext4_extent_header *ehp = path->ep_header; struct ext4_extent_index *first, *last, *l, *r, *m; first = (struct ext4_extent_index *)(char *)(ehp + 1); last = first + ehp->eh_ecount - 1; l = first; r = last; while (l <= r) { m = l + (r - l) / 2; if (lbn < m->ei_blk) r = m - 1; else l = m + 1; } if (l == first) { path->ep_sparse_ext.e_blk = *first_lbn; path->ep_sparse_ext.e_len = first->ei_blk - *first_lbn; path->ep_sparse_ext.e_start_hi = 0; path->ep_sparse_ext.e_start_lo = 0; path->ep_is_sparse = true; return true; } path->ep_index = l - 1; *first_lbn = path->ep_index->ei_blk; if (path->ep_index < last) *last_lbn = l->ei_blk - 1; return false; } static void ext4_ext_binsearch(struct inode *ip, struct ext4_extent_path *path, daddr_t lbn, daddr_t first_lbn, daddr_t last_lbn) { struct ext4_extent_header *ehp = path->ep_header; struct ext4_extent *first, *l, *r, *m; if (ehp->eh_ecount == 0) return; first = (struct ext4_extent *)(char *)(ehp + 1); l = first; r = first + ehp->eh_ecount - 1; while (l <= r) { m = l + (r - l) / 2; if (lbn < m->e_blk) r = m - 1; else l = m + 1; } if (l == first) { path->ep_sparse_ext.e_blk = first_lbn; path->ep_sparse_ext.e_len = first->e_blk - first_lbn; path->ep_sparse_ext.e_start_hi = 0; path->ep_sparse_ext.e_start_lo = 0; path->ep_is_sparse = true; return; } path->ep_ext = l - 1; if (path->ep_ext->e_blk + path->ep_ext->e_len <= lbn) { path->ep_sparse_ext.e_blk = path->ep_ext->e_blk + path->ep_ext->e_len; if (l <= (first + ehp->eh_ecount - 1)) path->ep_sparse_ext.e_len = l->e_blk - path->ep_sparse_ext.e_blk; else path->ep_sparse_ext.e_len = last_lbn - path->ep_sparse_ext.e_blk + 1; path->ep_sparse_ext.e_start_hi = 0; path->ep_sparse_ext.e_start_lo = 0; path->ep_is_sparse = true; } } /* * Find a block in ext4 extent cache. */ int ext4_ext_in_cache(struct inode *ip, daddr_t lbn, struct ext4_extent *ep) { struct ext4_extent_cache *ecp; int ret = EXT4_EXT_CACHE_NO; ecp = &ip->inode_ext.e2fs.i_ext_cache; /* cache is invalid */ if (ecp->ec_type == EXT4_EXT_CACHE_NO) return ret; if (lbn >= ecp->ec_blk && lbn < ecp->ec_blk + ecp->ec_len) { ep->e_blk = ecp->ec_blk; ep->e_start_lo = ecp->ec_start & 0xffffffff; ep->e_start_hi = ecp->ec_start >> 32 & 0xffff; ep->e_len = ecp->ec_len; ret = ecp->ec_type; } return ret; } /* * Put an ext4_extent structure in ext4 cache. */ void ext4_ext_put_cache(struct inode *ip, struct ext4_extent *ep, int type) { struct ext4_extent_cache *ecp; ecp = &ip->inode_ext.e2fs.i_ext_cache; ecp->ec_type = type; ecp->ec_blk = ep->e_blk; ecp->ec_len = ep->e_len; ecp->ec_start = (daddr_t)ep->e_start_hi << 32 | ep->e_start_lo; } /* * Find an extent. */ struct ext4_extent_path * ext4_ext_find_extent(struct m_ext2fs *fs, struct inode *ip, daddr_t lbn, struct ext4_extent_path *path) { struct ext4_extent_header *ehp; uint16_t i; int error, size; daddr_t nblk; ehp = (struct ext4_extent_header *)ip->i_din.e2fs_din->e2di_blocks; if (ehp->eh_magic != EXT4_EXT_MAGIC) return NULL; path->ep_header = ehp; daddr_t first_lbn = 0; daddr_t last_lbn = lblkno(ip->i_e2fs, ip->i_size); for (i = ehp->eh_depth; i != 0; --i) { path->ep_depth = i; path->ep_ext = NULL; if (ext4_ext_binsearch_index(ip, path, lbn, &first_lbn, &last_lbn)) { return path; } nblk = (daddr_t)path->ep_index->ei_leaf_hi << 32 | path->ep_index->ei_leaf_lo; size = blksize(fs, ip, nblk); if (path->ep_bp != NULL) { brelse(path->ep_bp, 0); path->ep_bp = NULL; } error = bread(ip->i_devvp, fsbtodb(fs, nblk), size, 0, &path->ep_bp); if (error) { brelse(path->ep_bp, 0); path->ep_bp = NULL; return NULL; } ehp = (struct ext4_extent_header *)path->ep_bp->b_data; path->ep_header = ehp; } path->ep_depth = i; path->ep_ext = NULL; path->ep_index = NULL; path->ep_is_sparse = false; ext4_ext_binsearch(ip, path, lbn, first_lbn, last_lbn); return path; }