X-Git-Url: http://git.sven.stormbind.net/?p=sven%2Fexfat-utils.git;a=blobdiff_plain;f=libexfat%2Fcluster.c;h=980e1cd5358b4fb8f6efdf5ff01f5cfae5aee2e6;hp=8bea507bf411569363fe4e796950ecab8eb185b1;hb=307c5fc8fe46baa8a1968f32a41d47d19cfcbf0a;hpb=4cb393cfd9b0ab69392612521ee3dbe481ec492d diff --git a/libexfat/cluster.c b/libexfat/cluster.c index 8bea507..980e1cd 100644 --- a/libexfat/cluster.c +++ b/libexfat/cluster.c @@ -2,7 +2,7 @@ cluster.c (03.09.09) exFAT file system implementation library. - Copyright (C) 2009, 2010 Andrew Nayenko + Copyright (C) 2010-2013 Andrew Nayenko This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -80,7 +80,7 @@ cluster_t exfat_next_cluster(const struct exfat* ef, return cluster + 1; fat_offset = s2o(ef, le32_to_cpu(ef->sb->fat_sector_start)) + cluster * sizeof(cluster_t); - exfat_read_raw(&next, sizeof(next), fat_offset, ef->fd); + exfat_pread(ef->dev, &next, sizeof(next), fat_offset); return le32_to_cpu(next); } @@ -99,55 +99,39 @@ cluster_t exfat_advance_cluster(const struct exfat* ef, { node->fptr_cluster = exfat_next_cluster(ef, node, node->fptr_cluster); if (CLUSTER_INVALID(node->fptr_cluster)) - break; + break; /* the caller should handle this and print appropriate + error message */ } node->fptr_index = count; return node->fptr_cluster; } -static cluster_t find_bit_and_set(uint8_t* bitmap, cluster_t start, - cluster_t end) +static cluster_t find_bit_and_set(uint8_t* bitmap, size_t start, size_t end) { - const cluster_t mid_start = (start + 7) / 8 * 8; - const cluster_t mid_end = end / 8 * 8; - cluster_t c; - cluster_t byte; - - for (c = start; c < mid_start; c++) - if (BMAP_GET(bitmap, c) == 0) - { - BMAP_SET(bitmap, c); - return c + EXFAT_FIRST_DATA_CLUSTER; - } - - for (byte = mid_start / 8; byte < mid_end / 8; byte++) - if (bitmap[byte] != 0xff) - { - cluster_t bit; - - for (bit = 0; bit < 8; bit++) - if (!(bitmap[byte] & (1u << bit))) - { - bitmap[byte] |= (1u << bit); - return byte * 8 + bit + EXFAT_FIRST_DATA_CLUSTER; - } - } - - for (c = mid_end; c < end; c++) - if (BMAP_GET(bitmap, c) == 0) - { - BMAP_SET(bitmap, c); - return c + EXFAT_FIRST_DATA_CLUSTER; - } + const size_t start_index = start / 8; + const size_t end_index = DIV_ROUND_UP(end, 8); + size_t i; + size_t c; + for (i = start_index; i < end_index; i++) + { + if (bitmap[i] == 0xff) + continue; + for (c = MAX(i * 8, start); c < MIN((i + 1) * 8, end); c++) + if (BMAP_GET(bitmap, c) == 0) + { + BMAP_SET(bitmap, c); + return c + EXFAT_FIRST_DATA_CLUSTER; + } + } return EXFAT_CLUSTER_END; } void exfat_flush_cmap(struct exfat* ef) { - exfat_write_raw(ef->cmap.chunk, (ef->cmap.chunk_size + 7) / 8, - exfat_c2o(ef, ef->cmap.start_cluster), ef->fd); - ef->cmap.dirty = 0; + exfat_pwrite(ef->dev, ef->cmap.chunk, (ef->cmap.chunk_size + 7) / 8, + exfat_c2o(ef, ef->cmap.start_cluster)); + ef->cmap.dirty = false; } static void set_next_cluster(const struct exfat* ef, int contiguous, @@ -161,7 +145,7 @@ static void set_next_cluster(const struct exfat* ef, int contiguous, fat_offset = s2o(ef, le32_to_cpu(ef->sb->fat_sector_start)) + current * sizeof(cluster_t); next_le32 = cpu_to_le32(next); - exfat_write_raw(&next_le32, sizeof(next_le32), fat_offset, ef->fd); + exfat_pwrite(ef->dev, &next_le32, sizeof(next_le32), fat_offset); } static cluster_t allocate_cluster(struct exfat* ef, cluster_t hint) @@ -181,22 +165,20 @@ static cluster_t allocate_cluster(struct exfat* ef, cluster_t hint) return EXFAT_CLUSTER_END; } - ef->cmap.dirty = 1; - /* FIXME update percentage of used space */ + ef->cmap.dirty = true; return cluster; } static void free_cluster(struct exfat* ef, cluster_t cluster) { if (CLUSTER_INVALID(cluster)) - exfat_bug("attempting to free invalid cluster"); - if (cluster < EXFAT_FIRST_DATA_CLUSTER || - cluster - EXFAT_FIRST_DATA_CLUSTER >= ef->cmap.size) - exfat_bug("bad cluster 0x%x (0x%x)", cluster, ef->cmap.size); + exfat_bug("freeing invalid cluster 0x%x", cluster); + if (cluster - EXFAT_FIRST_DATA_CLUSTER >= ef->cmap.size) + exfat_bug("freeing non-existing cluster 0x%x (0x%x)", cluster, + ef->cmap.size); BMAP_CLR(ef->cmap.chunk, cluster - EXFAT_FIRST_DATA_CLUSTER); - ef->cmap.dirty = 1; - /* FIXME update percentage of used space */ + ef->cmap.dirty = true; } static void make_noncontiguous(const struct exfat* ef, cluster_t first, @@ -227,7 +209,7 @@ static int grow_file(struct exfat* ef, struct exfat_node* node, previous = exfat_advance_cluster(ef, node, current - 1); if (CLUSTER_INVALID(previous)) { - exfat_error("invalid cluster in file"); + exfat_error("invalid cluster 0x%x while growing", previous); return -EIO; } } @@ -292,7 +274,7 @@ static int shrink_file(struct exfat* ef, struct exfat_node* node, current - difference - 1); if (CLUSTER_INVALID(last)) { - exfat_error("invalid cluster in file"); + exfat_error("invalid cluster 0x%x while shrinking", last); return -EIO; } previous = exfat_next_cluster(ef, node, last); @@ -311,7 +293,8 @@ static int shrink_file(struct exfat* ef, struct exfat_node* node, { if (CLUSTER_INVALID(previous)) { - exfat_error("invalid cluster in file"); + exfat_error("invalid cluster 0x%x while freeing after shrink", + previous); return -EIO; } next = exfat_next_cluster(ef, node, previous); @@ -325,37 +308,38 @@ static int shrink_file(struct exfat* ef, struct exfat_node* node, static void erase_raw(struct exfat* ef, size_t size, off_t offset) { - exfat_write_raw(ef->zero_sector, size, offset, ef->fd); + exfat_pwrite(ef->dev, ef->zero_cluster, size, offset); } static int erase_range(struct exfat* ef, struct exfat_node* node, uint64_t begin, uint64_t end) { - uint64_t sector_boundary; + uint64_t cluster_boundary; cluster_t cluster; if (begin >= end) return 0; - sector_boundary = (node->size | (SECTOR_SIZE(*ef->sb) - 1)) + 1; + cluster_boundary = (begin | (CLUSTER_SIZE(*ef->sb) - 1)) + 1; cluster = exfat_advance_cluster(ef, node, - node->size / CLUSTER_SIZE(*ef->sb)); + begin / CLUSTER_SIZE(*ef->sb)); if (CLUSTER_INVALID(cluster)) { - exfat_error("invalid cluster in file"); + exfat_error("invalid cluster 0x%x while erasing", cluster); return -EIO; } - /* erase from the beginning to the closest sector boundary */ - erase_raw(ef, MIN(sector_boundary, end) - node->size, - exfat_c2o(ef, cluster) + node->size % CLUSTER_SIZE(*ef->sb)); - /* erase whole sectors */ - while (sector_boundary < end) + /* erase from the beginning to the closest cluster boundary */ + erase_raw(ef, MIN(cluster_boundary, end) - begin, + exfat_c2o(ef, cluster) + begin % CLUSTER_SIZE(*ef->sb)); + /* erase whole clusters */ + while (cluster_boundary < end) { - if (sector_boundary % CLUSTER_SIZE(*ef->sb) == 0) - cluster = exfat_next_cluster(ef, node, cluster); - erase_raw(ef, SECTOR_SIZE(*ef->sb), - exfat_c2o(ef, cluster) + sector_boundary % CLUSTER_SIZE(*ef->sb)); - sector_boundary += SECTOR_SIZE(*ef->sb); + cluster = exfat_next_cluster(ef, node, cluster); + /* the cluster cannot be invalid because we have just allocated it */ + if (CLUSTER_INVALID(cluster)) + exfat_bug("invalid cluster 0x%x after allocation", cluster); + erase_raw(ef, CLUSTER_SIZE(*ef->sb), exfat_c2o(ef, cluster)); + cluster_boundary += CLUSTER_SIZE(*ef->sb); } return 0; }