/** * lcnalloc.c - Cluster (de)allocation code. Originated from the Linux-NTFS project. * * Copyright (c) 2002-2004 Anton Altaparmakov * Copyright (c) 2004-2007 Szabolcs Szakacsits * Copyright (c) 2004 Yura Pakhuchiy * * This program/include file is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as published * by the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program/include file is distributed in the hope that it will be * useful, but WITHOUT ANY WARRANTY; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program (in the main directory of the NTFS-3G * distribution in the file COPYING); if not, write to the Free Software * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #ifdef HAVE_STDLIB_H #include #endif #ifdef HAVE_STDIO_H #include #endif #ifdef HAVE_ERRNO_H #include #endif #include "types.h" #include "attrib.h" #include "bitmap.h" #include "debug.h" #include "runlist.h" #include "volume.h" #include "lcnalloc.h" #include "logging.h" #include "misc.h" #define NTFS_LCNALLOC_BSIZE 512 #define NTFS_LCNALLOC_SKIP 4096 static void ntfs_cluster_set_zone_pos(LCN zone_start, LCN zone_end, LCN *zone_pos, LCN tc, LCN bmp_initial_pos) { ntfs_log_trace("Before: zone_pos: %lld\n", (long long)*zone_pos); if (tc >= zone_end) { *zone_pos = zone_start; // FIXME: seems to be bogus and only MFT zone used it if (!zone_end) *zone_pos = 0; } else if ((bmp_initial_pos >= *zone_pos || tc > *zone_pos) && tc >= zone_start) *zone_pos = tc; ntfs_log_trace("After: zone_pos: %lld\n", (long long)*zone_pos); } static int ntfs_cluster_update_zone_pos(ntfs_volume *vol, u8 zone, LCN tc, LCN bmp_initial_pos) { ntfs_log_trace("tc = %lld, zone = %d\n", (long long)tc, zone); switch (zone) { case 1: ntfs_cluster_set_zone_pos(vol->mft_lcn, vol->mft_zone_end, &vol->mft_zone_pos, tc, bmp_initial_pos); break; case 2: ntfs_cluster_set_zone_pos(vol->mft_zone_end, vol->nr_clusters, &vol->data1_zone_pos, tc, bmp_initial_pos); break; case 4: ntfs_cluster_set_zone_pos(0, vol->mft_zone_start, &vol->data2_zone_pos, tc, bmp_initial_pos); break; default: ntfs_log_error("Invalid zone: %d\n", zone); return -1; } return 0; } /** * ntfs_cluster_alloc - allocate clusters on an ntfs volume * @vol: mounted ntfs volume on which to allocate the clusters * @start_vcn: vcn to use for the first allocated cluster * @count: number of clusters to allocate * @start_lcn: starting lcn at which to allocate the clusters (or -1 if none) * @zone: zone from which to allocate the clusters * * Allocate @count clusters preferably starting at cluster @start_lcn or at the * current allocator position if @start_lcn is -1, on the mounted ntfs volume * @vol. @zone is either DATA_ZONE for allocation of normal clusters and * MFT_ZONE for allocation of clusters for the master file table, i.e. the * $MFT/$DATA attribute. * * On success return a runlist describing the allocated cluster(s). * * On error return NULL with errno set to the error code. * * Notes on the allocation algorithm * ================================= * * There are two data zones. First is the area between the end of the mft zone * and the end of the volume, and second is the area between the start of the * volume and the start of the mft zone. On unmodified/standard NTFS 1.x * volumes, the second data zone doesn't exist due to the mft zone being * expanded to cover the start of the volume in order to reserve space for the * mft bitmap attribute. * * This is not the prettiest function but the complexity stems from the need of * implementing the mft vs data zoned approach and from the fact that we have * access to the lcn bitmap via up to NTFS_LCNALLOC_BSIZE bytes at a time, so we * need to cope with crossing over boundaries of two buffers. Further, the fact * that the allocator allows for caller supplied hints as to the location of * where allocation should begin and the fact that the allocator keeps track of * where in the data zones the next natural allocation should occur, contribute * to the complexity of the function. But it should all be worthwhile, because * this allocator should: 1) be a full implementation of the MFT zone approach * used by Windows, 2) cause reduction in fragmentation as much as possible, * and 3) be speedy in allocations (the code is not optimized for speed, but * the algorithm is, so further speed improvements are probably possible). * * FIXME: We should be monitoring cluster allocation and increment the MFT zone * size dynamically but this is something for the future. We will just cause * heavier fragmentation by not doing it and I am not even sure Windows would * grow the MFT zone dynamically, so it might even be correct not to do this. * The overhead in doing dynamic MFT zone expansion would be very large and * unlikely worth the effort. (AIA) * * TODO: I have added in double the required zone position pointer wrap around * logic which can be optimized to having only one of the two logic sets. * However, having the double logic will work fine, but if we have only one of * the sets and we get it wrong somewhere, then we get into trouble, so * removing the duplicate logic requires _very_ careful consideration of _all_ * possible code paths. So at least for now, I am leaving the double logic - * better safe than sorry... (AIA) */ runlist *ntfs_cluster_alloc(ntfs_volume *vol, VCN start_vcn, s64 count, LCN start_lcn, const NTFS_CLUSTER_ALLOCATION_ZONES zone) { LCN zone_start, zone_end, bmp_pos, bmp_initial_pos, last_read_pos, lcn; LCN prev_lcn = 0, prev_run_len = 0, mft_zone_size; s64 clusters, br; runlist *rl = NULL, *trl; u8 *buf, *byte; int err = 0, rlpos, rlsize, buf_size; u8 pass, done_zones, search_zone, need_writeback, bit; u8 first_try = 1; ntfs_log_trace("Entering with count = 0x%llx, start_lcn = 0x%llx, " "zone = %s_ZONE.\n", (long long)count, (long long) start_lcn, zone == MFT_ZONE ? "MFT" : "DATA"); if (!vol || count < 0 || start_lcn < -1 || !vol->lcnbmp_na || (s8)zone < FIRST_ZONE || zone > LAST_ZONE) { errno = EINVAL; ntfs_log_perror("%s: vcn: %lld, count: %lld, lcn: %lld", __FUNCTION__, (long long)start_vcn, (long long)count, (long long)start_lcn); return NULL; } /* Return empty runlist if @count == 0 */ if (!count) { rl = ntfs_malloc(0x1000); if (!rl) return NULL; rl[0].vcn = start_vcn; rl[0].lcn = LCN_RL_NOT_MAPPED; rl[0].length = 0; return rl; } /* Allocate memory. */ buf = ntfs_malloc(NTFS_LCNALLOC_BSIZE); if (!buf) return NULL; /* * If no specific @start_lcn was requested, use the current data zone * position, otherwise use the requested @start_lcn but make sure it * lies outside the mft zone. Also set done_zones to 0 (no zones done) * and pass depending on whether we are starting inside a zone (1) or * at the beginning of a zone (2). If requesting from the MFT_ZONE, * we either start at the current position within the mft zone or at * the specified position. If the latter is out of bounds then we start * at the beginning of the MFT_ZONE. */ done_zones = 0; pass = 1; /* * zone_start and zone_end are the current search range. search_zone * is 1 for mft zone, 2 for data zone 1 (end of mft zone till end of * volume) and 4 for data zone 2 (start of volume till start of mft * zone). */ zone_start = start_lcn; if (zone_start < 0) { if (zone == DATA_ZONE) zone_start = vol->data1_zone_pos; else zone_start = vol->mft_zone_pos; if (!zone_start) { /* * Zone starts at beginning of volume which means a * single pass is sufficient. */ pass = 2; } } else if (zone == DATA_ZONE && zone_start >= vol->mft_zone_start && zone_start < vol->mft_zone_end) { zone_start = vol->mft_zone_end; /* * Starting at beginning of data1_zone which means a single * pass in this zone is sufficient. */ pass = 2; } else if (zone == MFT_ZONE && (zone_start < vol->mft_zone_start || zone_start >= vol->mft_zone_end)) { zone_start = vol->mft_lcn; if (!vol->mft_zone_end) zone_start = 0; /* * Starting at beginning of volume which means a single pass * is sufficient. */ pass = 2; } if (zone == MFT_ZONE) { zone_end = vol->mft_zone_end; search_zone = 1; } else /* if (zone == DATA_ZONE) */ { /* Skip searching the mft zone. */ done_zones |= 1; if (zone_start >= vol->mft_zone_end) { zone_end = vol->nr_clusters; search_zone = 2; } else { zone_end = vol->mft_zone_start; search_zone = 4; } } /* * bmp_pos is the current bit position inside the bitmap. We use * bmp_initial_pos to determine whether or not to do a zone switch. */ bmp_pos = bmp_initial_pos = zone_start; /* Loop until all clusters are allocated, i.e. clusters == 0. */ clusters = count; rlpos = rlsize = 0; while (1) { ntfs_log_trace("Start of outer while loop: done_zones = 0x%x, " "search_zone = %i, pass = %i, zone_start = " "0x%llx, zone_end = 0x%llx, bmp_initial_pos = " "0x%llx, bmp_pos = 0x%llx, rlpos = %i, rlsize = " "%i.\n", done_zones, search_zone, pass, (long long)zone_start, (long long)zone_end, (long long)bmp_initial_pos, (long long)bmp_pos, rlpos, rlsize); /* Loop until we run out of free clusters. */ last_read_pos = bmp_pos >> 3; ntfs_log_trace("last_read_pos = 0x%llx.\n", (long long)last_read_pos); br = ntfs_attr_pread(vol->lcnbmp_na, last_read_pos, NTFS_LCNALLOC_BSIZE, buf); if (br <= 0) { if (!br) { /* Reached end of attribute. */ ntfs_log_trace("End of attribute reached. Skipping " "to zone_pass_done.\n"); goto zone_pass_done; } err = errno; ntfs_log_perror("ntfs_attr_pread() failed"); goto err_ret; } /* * We might have read less than NTFS_LCNALLOC_BSIZE bytes if we are close to * the end of the attribute. */ buf_size = (int)br << 3; lcn = bmp_pos & 7; bmp_pos &= ~7; need_writeback = 0; ntfs_log_trace("Before inner while loop: buf_size = %i, lcn = " "0x%llx, bmp_pos = 0x%llx, need_writeback = %i.\n", buf_size, (long long)lcn, (long long)bmp_pos, need_writeback); while (lcn < buf_size && lcn + bmp_pos < zone_end) { byte = buf + (lcn >> 3); ntfs_log_trace("In inner while loop: buf_size = %i, lcn = " "0x%llx, bmp_pos = 0x%llx, " "need_writeback = %i, byte ofs = 0x%x, " "*byte = 0x%x.\n", buf_size, (long long)lcn, (long long)bmp_pos, need_writeback, (unsigned int)(lcn >> 3), (unsigned int)*byte); /* Skip full bytes. */ if (*byte == 0xff) { lcn = (lcn + 8) & ~7; ntfs_log_trace("continuing while loop 1.\n"); if (first_try) { first_try = 0; lcn += NTFS_LCNALLOC_SKIP; } continue; } bit = 1 << (lcn & 7); ntfs_log_trace("bit = %i.\n", bit); /* If the bit is already set, go onto the next one. */ if (*byte & bit) { lcn++; ntfs_log_trace("continuing while loop 2.\n"); if (first_try) { first_try = 0; lcn += NTFS_LCNALLOC_SKIP; } continue; } /* Reallocate memory if necessary. */ if ((rlpos + 2) * (int)sizeof(runlist) >= rlsize) { ntfs_log_trace("Reallocating space.\n"); if (!rl) ntfs_log_trace("First free bit is at LCN = " "0x%llx.\n", (long long)(lcn + bmp_pos)); rlsize += 4096; trl = (runlist*)realloc(rl, rlsize); if (!trl) { err = ENOMEM; ntfs_log_perror("Failed to allocate memory"); goto wb_err_ret; } rl = trl; ntfs_log_trace("Reallocated memory, rlsize = " "0x%x.\n", rlsize); } /* Allocate the bitmap bit. */ *byte |= bit; /* We need to write this bitmap buffer back to disk! */ need_writeback = 1; ntfs_log_trace("*byte = 0x%x, need_writeback is set.\n", (unsigned int)*byte); /* * Coalesce with previous run if adjacent LCNs. * Otherwise, append a new run. */ ntfs_log_trace("Adding run (lcn 0x%llx, len 0x%llx), " "prev_lcn = 0x%llx, lcn = 0x%llx, " "bmp_pos = 0x%llx, prev_run_len = " "0x%llx, rlpos = %i.\n", (long long)(lcn + bmp_pos), 1LL, (long long)prev_lcn, (long long)lcn, (long long)bmp_pos, (long long)prev_run_len, rlpos); if (prev_lcn == lcn + bmp_pos - prev_run_len && rlpos) { ntfs_log_trace("Coalescing to run (lcn 0x%llx, len " "0x%llx).\n", (long long)rl[rlpos - 1].lcn, (long long) rl[rlpos - 1].length); rl[rlpos - 1].length = ++prev_run_len; ntfs_log_trace("Run now (lcn 0x%llx, len 0x%llx), " "prev_run_len = 0x%llx.\n", (long long)rl[rlpos - 1].lcn, (long long)rl[rlpos - 1].length, (long long)prev_run_len); } else { if (rlpos) { ntfs_log_trace("Adding new run, (previous " "run lcn 0x%llx, len 0x%llx).\n", (long long) rl[rlpos - 1].lcn, (long long) rl[rlpos - 1].length); rl[rlpos].vcn = rl[rlpos - 1].vcn + prev_run_len; } else { ntfs_log_trace("Adding new run, is first run.\n"); rl[rlpos].vcn = start_vcn; } rl[rlpos].lcn = prev_lcn = lcn + bmp_pos; rl[rlpos].length = prev_run_len = 1; rlpos++; } /* Done? */ if (!--clusters) { if (ntfs_cluster_update_zone_pos(vol, search_zone, lcn + bmp_pos + 1 + NTFS_LCNALLOC_SKIP, bmp_initial_pos)) { free(rl); free(buf); return NULL; } goto done_ret; } lcn++; } bmp_pos += buf_size; ntfs_log_trace("After inner while loop: buf_size = 0x%x, lcn = " "0x%llx, bmp_pos = 0x%llx, need_writeback = %i.\n", buf_size, (long long)lcn, (long long)bmp_pos, need_writeback); if (need_writeback) { s64 bw; ntfs_log_trace("Writing back.\n"); need_writeback = 0; bw = ntfs_attr_pwrite(vol->lcnbmp_na, last_read_pos, br, buf); if (bw != br) { if (bw == -1) err = errno; else err = EIO; ntfs_log_perror("Bitmap writeback failed in " "read next buffer code path"); goto err_ret; } } if (bmp_pos < zone_end) { ntfs_log_trace("Continuing outer while loop, bmp_pos = " "0x%llx, zone_end = 0x%llx.\n", (long long)bmp_pos, (long long)zone_end); continue; } zone_pass_done: /* Finished with the current zone pass. */ ntfs_log_trace("At zone_pass_done, pass = %i.\n", pass); if (pass == 1) { /* * Now do pass 2, scanning the first part of the zone * we omitted in pass 1. */ pass = 2; zone_end = zone_start; switch (search_zone) { case 1: /* mft_zone */ zone_start = vol->mft_zone_start; break; case 2: /* data1_zone */ zone_start = vol->mft_zone_end; break; case 4: /* data2_zone */ zone_start = 0; break; default: NTFS_BUG("switch (search_zone) 2"); } /* Sanity check. */ if (zone_end < zone_start) zone_end = zone_start; bmp_pos = zone_start; ntfs_log_trace("Continuing outer while loop, pass = 2, " "zone_start = 0x%llx, zone_end = " "0x%llx, bmp_pos = 0x%llx.\n", zone_start, zone_end, bmp_pos); continue; } /* pass == 2 */ done_zones_check: ntfs_log_trace("At done_zones_check, search_zone = %i, done_zones " "before = 0x%x, done_zones after = 0x%x.\n", search_zone, done_zones, done_zones | search_zone); done_zones |= search_zone; if (done_zones < 7) { ntfs_log_trace("Switching zone.\n"); /* Now switch to the next zone we haven't done yet. */ pass = 1; if (rlpos) { LCN tc; tc = rl[rlpos - 1].lcn + rl[rlpos - 1].length + NTFS_LCNALLOC_SKIP; if (ntfs_cluster_update_zone_pos(vol, search_zone, tc, bmp_initial_pos)) return NULL; } switch (search_zone) { case 1: ntfs_log_trace("Zone switch: mft -> data1\n"); switch_to_data1_zone: search_zone = 2; zone_start = bmp_initial_pos = vol->data1_zone_pos; zone_end = vol->nr_clusters; if (zone_start == vol->mft_zone_end) pass = 2; if (zone_start >= zone_end) { vol->data1_zone_pos = zone_start = vol->mft_zone_end; pass = 2; } break; case 2: ntfs_log_trace("Zone switch: data1 -> data2\n"); search_zone = 4; zone_start = bmp_initial_pos = vol->data2_zone_pos; zone_end = vol->mft_zone_start; if (!zone_start) pass = 2; if (zone_start >= zone_end) { vol->data2_zone_pos = zone_start = bmp_initial_pos = 0; pass = 2; } break; case 4: ntfs_log_trace("Zone switch: data2 -> data1\n"); goto switch_to_data1_zone; /* See above. */ default: NTFS_BUG("switch (search_zone) 3"); } ntfs_log_trace("After zone switch, search_zone = %i, pass = " "%i, bmp_initial_pos = 0x%llx, " "zone_start = 0x%llx, zone_end = " "0x%llx.\n", search_zone, pass, (long long)bmp_initial_pos, (long long)zone_start, (long long)zone_end); bmp_pos = zone_start; if (zone_start == zone_end) { ntfs_log_trace("Empty zone, going to " "done_zones_check.\n"); /* Empty zone. Don't bother searching it. */ goto done_zones_check; } ntfs_log_trace("Continuing outer while loop.\n"); continue; } /* done_zones == 7 */ ntfs_log_trace("All zones are finished.\n"); /* * All zones are finished! If DATA_ZONE, shrink mft zone. If * MFT_ZONE, we have really run out of space. */ mft_zone_size = vol->mft_zone_end - vol->mft_zone_start; ntfs_log_trace("vol->mft_zone_start = 0x%llx, vol->mft_zone_end = " "0x%llx, mft_zone_size = 0x%llx.\n", (long long)vol->mft_zone_start, (long long)vol->mft_zone_end, (long long)mft_zone_size); if (zone == MFT_ZONE || mft_zone_size <= 0) { ntfs_log_trace("No free clusters left, going to err_ret.\n"); /* Really no more space left on device. */ err = ENOSPC; goto err_ret; } /* zone == DATA_ZONE && mft_zone_size > 0 */ ntfs_log_trace("Shrinking mft zone.\n"); zone_end = vol->mft_zone_end; mft_zone_size >>= 1; if (mft_zone_size > 0) vol->mft_zone_end = vol->mft_zone_start + mft_zone_size; else /* mft zone and data2 zone no longer exist. */ vol->data2_zone_pos = vol->mft_zone_start = vol->mft_zone_end = 0; if (vol->mft_zone_pos >= vol->mft_zone_end) { vol->mft_zone_pos = vol->mft_lcn; if (!vol->mft_zone_end) vol->mft_zone_pos = 0; } bmp_pos = zone_start = bmp_initial_pos = vol->data1_zone_pos = vol->mft_zone_end; search_zone = 2; pass = 2; done_zones &= ~2; ntfs_log_trace("After shrinking mft zone, mft_zone_size = 0x%llx, " "vol->mft_zone_start = 0x%llx, " "vol->mft_zone_end = 0x%llx, vol->mft_zone_pos " "= 0x%llx, search_zone = 2, pass = 2, " "dones_zones = 0x%x, zone_start = 0x%llx, " "zone_end = 0x%llx, vol->data1_zone_pos = " "0x%llx, continuing outer while loop.\n", (long long)mft_zone_size, (long long)vol->mft_zone_start, (long long)vol->mft_zone_end, (long long)vol->mft_zone_pos, done_zones, (long long)zone_start, (long long)zone_end, (long long)vol->data1_zone_pos); } ntfs_log_debug("After outer while loop.\n"); done_ret: ntfs_log_debug("At done_ret.\n"); /* Add runlist terminator element. */ rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length; rl[rlpos].lcn = LCN_RL_NOT_MAPPED; rl[rlpos].length = 0; if (need_writeback) { s64 bw; ntfs_log_trace("Writing back.\n"); need_writeback = 0; bw = ntfs_attr_pwrite(vol->lcnbmp_na, last_read_pos, br, buf); if (bw != br) { if (bw < 0) err = errno; else err = EIO; ntfs_log_perror("Bitmap writeback failed"); goto err_ret; } } done_err_ret: ntfs_log_debug("At done_err_ret (follows done_ret).\n"); free(buf); /* Done! */ if (!err) return rl; ntfs_log_perror("Failed to allocate clusters"); errno = err; return NULL; wb_err_ret: ntfs_log_trace("At wb_err_ret.\n"); if (need_writeback) { s64 bw; ntfs_log_trace("Writing back.\n"); need_writeback = 0; bw = ntfs_attr_pwrite(vol->lcnbmp_na, last_read_pos, br, buf); if (bw != br) { if (bw < 0) err = errno; else err = EIO; ntfs_log_trace("Bitmap writeback failed in error code path " "with error code %i.\n", err); } } err_ret: ntfs_log_trace("At err_ret.\n"); if (rl) { if (err == ENOSPC) { ntfs_log_trace("err = ENOSPC, first free lcn = 0x%llx, could " "allocate up to = 0x%llx clusters.\n", (long long)rl[0].lcn, (long long)count - clusters); } /* Add runlist terminator element. */ rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length; rl[rlpos].lcn = LCN_RL_NOT_MAPPED; rl[rlpos].length = 0; /* Deallocate all allocated clusters. */ ntfs_log_trace("Deallocating allocated clusters.\n"); ntfs_cluster_free_from_rl(vol, rl); /* Free the runlist. */ free(rl); rl = NULL; } else { if (err == ENOSPC) { ntfs_log_trace("No space left at all, err = ENOSPC, first " "free lcn = 0x%llx.\n", (long long)vol->data1_zone_pos); } } ntfs_log_trace("rl = NULL, going to done_err_ret.\n"); goto done_err_ret; } /** * ntfs_cluster_free_from_rl - free clusters from runlist * @vol: mounted ntfs volume on which to free the clusters * @rl: runlist from which deallocate clusters * * On success return 0 and on error return -1 with errno set to the error code. */ int ntfs_cluster_free_from_rl(ntfs_volume *vol, runlist *rl) { ntfs_log_trace("Entering.\n"); for (; rl->length; rl++) { ntfs_log_trace("Dealloc lcn 0x%llx, len 0x%llx.\n", (long long)rl->lcn, (long long)rl->length); if (rl->lcn >= 0 && ntfs_bitmap_clear_run(vol->lcnbmp_na, rl->lcn, rl->length)) { int eo = errno; ntfs_log_trace("Eeek! Deallocation of clusters failed.\n"); errno = eo; return -1; } } return 0; } /** * ntfs_cluster_free - free clusters on an ntfs volume * @vol: mounted ntfs volume on which to free the clusters * @na: attribute whose runlist describes the clusters to free * @start_vcn: vcn in @rl at which to start freeing clusters * @count: number of clusters to free or -1 for all clusters * * Free @count clusters starting at the cluster @start_vcn in the runlist * described by the attribute @na from the mounted ntfs volume @vol. * * If @count is -1, all clusters from @start_vcn to the end of the runlist * are deallocated. * * On success return the number of deallocated clusters (not counting sparse * clusters) and on error return -1 with errno set to the error code. */ int ntfs_cluster_free(ntfs_volume *vol, ntfs_attr *na, VCN start_vcn, s64 count) { runlist *rl; s64 nr_freed, delta, to_free; if (!vol || !vol->lcnbmp_na || !na || start_vcn < 0 || (count < 0 && count != -1)) { ntfs_log_trace("Invalid arguments!\n"); errno = EINVAL; return -1; } ntfs_log_trace("Entering for inode 0x%llx, attr 0x%x, count 0x%llx, " "vcn 0x%llx.\n", (unsigned long long)na->ni->mft_no, na->type, (long long)count, (long long)start_vcn); rl = ntfs_attr_find_vcn(na, start_vcn); if (!rl) { if (errno == ENOENT) return 0; else return -1; } if (rl->lcn < 0 && rl->lcn != LCN_HOLE) { errno = EIO; return -1; } /* Find the starting cluster inside the run that needs freeing. */ delta = start_vcn - rl->vcn; /* The number of clusters in this run that need freeing. */ to_free = rl->length - delta; if (count >= 0 && to_free > count) to_free = count; if (rl->lcn != LCN_HOLE) { /* Do the actual freeing of the clusters in this run. */ if (ntfs_bitmap_clear_run(vol->lcnbmp_na, rl->lcn + delta, to_free)) return -1; /* We have freed @to_free real clusters. */ nr_freed = to_free; } else { /* No real clusters were freed. */ nr_freed = 0; } /* Go to the next run and adjust the number of clusters left to free. */ ++rl; if (count >= 0) count -= to_free; /* * Loop over the remaining runs, using @count as a capping value, and * free them. */ for (; rl->length && count != 0; ++rl) { // FIXME: Need to try ntfs_attr_map_runlist() for attribute // list support! (AIA) if (rl->lcn < 0 && rl->lcn != LCN_HOLE) { // FIXME: Eeek! We need rollback! (AIA) ntfs_log_trace("Eeek! invalid lcn (= %lli). Should attempt " "to map runlist! Leaving inconsistent " "metadata!\n", (long long)rl->lcn); errno = EIO; return -1; } /* The number of clusters in this run that need freeing. */ to_free = rl->length; if (count >= 0 && to_free > count) to_free = count; if (rl->lcn != LCN_HOLE) { /* Do the actual freeing of the clusters in the run. */ if (ntfs_bitmap_clear_run(vol->lcnbmp_na, rl->lcn, to_free)) { int eo = errno; // FIXME: Eeek! We need rollback! (AIA) ntfs_log_trace("Eeek! bitmap clear run failed. " "Leaving inconsistent metadata!\n"); errno = eo; return -1; } /* We have freed @to_free real clusters. */ nr_freed += to_free; } if (count >= 0) count -= to_free; } if (count != -1 && count != 0) { // FIXME: Eeek! BUG() ntfs_log_trace("Eeek! count still not zero (= %lli). Leaving " "inconsistent metadata!\n", (long long)count); errno = EIO; return -1; } /* Done. Return the number of actual clusters that were freed. */ return nr_freed; }