| // SPDX-License-Identifier: GPL-2.0-or-later | |
| /* | |
| * lcnalloc.c - Cluster (de)allocation code. Part of the Linux-NTFS project. | |
| * | |
| * Copyright (c) 2004-2005 Anton Altaparmakov | |
| */ | |
| #ifdef NTFS_RW | |
| #include <linux/pagemap.h> | |
| #include "lcnalloc.h" | |
| #include "debug.h" | |
| #include "bitmap.h" | |
| #include "inode.h" | |
| #include "volume.h" | |
| #include "attrib.h" | |
| #include "malloc.h" | |
| #include "aops.h" | |
| #include "ntfs.h" | |
| /** | |
| * ntfs_cluster_free_from_rl_nolock - free clusters from runlist | |
| * @vol: mounted ntfs volume on which to free the clusters | |
| * @rl: runlist describing the clusters to free | |
| * | |
| * Free all the clusters described by the runlist @rl on the volume @vol. In | |
| * the case of an error being returned, at least some of the clusters were not | |
| * freed. | |
| * | |
| * Return 0 on success and -errno on error. | |
| * | |
| * Locking: - The volume lcn bitmap must be locked for writing on entry and is | |
| * left locked on return. | |
| */ | |
| int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol, | |
| const runlist_element *rl) | |
| { | |
| struct inode *lcnbmp_vi = vol->lcnbmp_ino; | |
| int ret = 0; | |
| ntfs_debug("Entering."); | |
| if (!rl) | |
| return 0; | |
| for (; rl->length; rl++) { | |
| int err; | |
| if (rl->lcn < 0) | |
| continue; | |
| err = ntfs_bitmap_clear_run(lcnbmp_vi, rl->lcn, rl->length); | |
| if (unlikely(err && (!ret || ret == -ENOMEM) && ret != err)) | |
| ret = err; | |
| } | |
| ntfs_debug("Done."); | |
| return ret; | |
| } | |
| /** | |
| * 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 | |
| * @is_extension: if 'true', this is an attribute extension | |
| * | |
| * 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 or | |
| * MFT_ZONE for allocation of clusters for the master file table, i.e. the | |
| * $MFT/$DATA attribute. | |
| * | |
| * @start_vcn specifies the vcn of the first allocated cluster. This makes | |
| * merging the resulting runlist with the old runlist easier. | |
| * | |
| * If @is_extension is 'true', the caller is allocating clusters to extend an | |
| * attribute and if it is 'false', the caller is allocating clusters to fill a | |
| * hole in an attribute. Practically the difference is that if @is_extension | |
| * is 'true' the returned runlist will be terminated with LCN_ENOENT and if | |
| * @is_extension is 'false' the runlist will be terminated with | |
| * LCN_RL_NOT_MAPPED. | |
| * | |
| * You need to check the return value with IS_ERR(). If this is false, the | |
| * function was successful and the return value is a runlist describing the | |
| * allocated cluster(s). If IS_ERR() is true, the function failed and | |
| * PTR_ERR() gives you 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 does not 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 in portions of up to 8192 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 NT, 2) cause reduction in | |
| * fragmentation, 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) | |
| * | |
| * Locking: - The volume lcn bitmap must be unlocked on entry and is unlocked | |
| * on return. | |
| * - This function takes the volume lcn bitmap lock for writing and | |
| * modifies the bitmap contents. | |
| */ | |
| runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn, | |
| const s64 count, const LCN start_lcn, | |
| const NTFS_CLUSTER_ALLOCATION_ZONES zone, | |
| const bool is_extension) | |
| { | |
| 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; | |
| loff_t i_size; | |
| struct inode *lcnbmp_vi; | |
| runlist_element *rl = NULL; | |
| struct address_space *mapping; | |
| struct page *page = NULL; | |
| u8 *buf, *byte; | |
| int err = 0, rlpos, rlsize, buf_size; | |
| u8 pass, done_zones, search_zone, need_writeback = 0, bit; | |
| ntfs_debug("Entering for start_vcn 0x%llx, count 0x%llx, start_lcn " | |
| "0x%llx, zone %s_ZONE.", (unsigned long long)start_vcn, | |
| (unsigned long long)count, | |
| (unsigned long long)start_lcn, | |
| zone == MFT_ZONE ? "MFT" : "DATA"); | |
| BUG_ON(!vol); | |
| lcnbmp_vi = vol->lcnbmp_ino; | |
| BUG_ON(!lcnbmp_vi); | |
| BUG_ON(start_vcn < 0); | |
| BUG_ON(count < 0); | |
| BUG_ON(start_lcn < -1); | |
| BUG_ON(zone < FIRST_ZONE); | |
| BUG_ON(zone > LAST_ZONE); | |
| /* Return NULL if @count is zero. */ | |
| if (!count) | |
| return NULL; | |
| /* Take the lcnbmp lock for writing. */ | |
| down_write(&vol->lcnbmp_lock); | |
| /* | |
| * 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; | |
| mapping = lcnbmp_vi->i_mapping; | |
| i_size = i_size_read(lcnbmp_vi); | |
| while (1) { | |
| ntfs_debug("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.", | |
| done_zones, search_zone, pass, | |
| (unsigned long long)zone_start, | |
| (unsigned long long)zone_end, | |
| (unsigned long long)bmp_initial_pos, | |
| (unsigned long long)bmp_pos, rlpos, rlsize); | |
| /* Loop until we run out of free clusters. */ | |
| last_read_pos = bmp_pos >> 3; | |
| ntfs_debug("last_read_pos 0x%llx.", | |
| (unsigned long long)last_read_pos); | |
| if (last_read_pos > i_size) { | |
| ntfs_debug("End of attribute reached. " | |
| "Skipping to zone_pass_done."); | |
| goto zone_pass_done; | |
| } | |
| if (likely(page)) { | |
| if (need_writeback) { | |
| ntfs_debug("Marking page dirty."); | |
| flush_dcache_page(page); | |
| set_page_dirty(page); | |
| need_writeback = 0; | |
| } | |
| ntfs_unmap_page(page); | |
| } | |
| page = ntfs_map_page(mapping, last_read_pos >> | |
| PAGE_SHIFT); | |
| if (IS_ERR(page)) { | |
| err = PTR_ERR(page); | |
| ntfs_error(vol->sb, "Failed to map page."); | |
| goto out; | |
| } | |
| buf_size = last_read_pos & ~PAGE_MASK; | |
| buf = page_address(page) + buf_size; | |
| buf_size = PAGE_SIZE - buf_size; | |
| if (unlikely(last_read_pos + buf_size > i_size)) | |
| buf_size = i_size - last_read_pos; | |
| buf_size <<= 3; | |
| lcn = bmp_pos & 7; | |
| bmp_pos &= ~(LCN)7; | |
| ntfs_debug("Before inner while loop: buf_size %i, lcn 0x%llx, " | |
| "bmp_pos 0x%llx, need_writeback %i.", buf_size, | |
| (unsigned long long)lcn, | |
| (unsigned long long)bmp_pos, need_writeback); | |
| while (lcn < buf_size && lcn + bmp_pos < zone_end) { | |
| byte = buf + (lcn >> 3); | |
| ntfs_debug("In inner while loop: buf_size %i, " | |
| "lcn 0x%llx, bmp_pos 0x%llx, " | |
| "need_writeback %i, byte ofs 0x%x, " | |
| "*byte 0x%x.", buf_size, | |
| (unsigned long long)lcn, | |
| (unsigned long long)bmp_pos, | |
| need_writeback, | |
| (unsigned int)(lcn >> 3), | |
| (unsigned int)*byte); | |
| /* Skip full bytes. */ | |
| if (*byte == 0xff) { | |
| lcn = (lcn + 8) & ~(LCN)7; | |
| ntfs_debug("Continuing while loop 1."); | |
| continue; | |
| } | |
| bit = 1 << (lcn & 7); | |
| ntfs_debug("bit 0x%x.", bit); | |
| /* If the bit is already set, go onto the next one. */ | |
| if (*byte & bit) { | |
| lcn++; | |
| ntfs_debug("Continuing while loop 2."); | |
| continue; | |
| } | |
| /* | |
| * Allocate more memory if needed, including space for | |
| * the terminator element. | |
| * ntfs_malloc_nofs() operates on whole pages only. | |
| */ | |
| if ((rlpos + 2) * sizeof(*rl) > rlsize) { | |
| runlist_element *rl2; | |
| ntfs_debug("Reallocating memory."); | |
| if (!rl) | |
| ntfs_debug("First free bit is at LCN " | |
| "0x%llx.", | |
| (unsigned long long) | |
| (lcn + bmp_pos)); | |
| rl2 = ntfs_malloc_nofs(rlsize + (int)PAGE_SIZE); | |
| if (unlikely(!rl2)) { | |
| err = -ENOMEM; | |
| ntfs_error(vol->sb, "Failed to " | |
| "allocate memory."); | |
| goto out; | |
| } | |
| memcpy(rl2, rl, rlsize); | |
| ntfs_free(rl); | |
| rl = rl2; | |
| rlsize += PAGE_SIZE; | |
| ntfs_debug("Reallocated memory, rlsize 0x%x.", | |
| rlsize); | |
| } | |
| /* Allocate the bitmap bit. */ | |
| *byte |= bit; | |
| /* We need to write this bitmap page to disk. */ | |
| need_writeback = 1; | |
| ntfs_debug("*byte 0x%x, need_writeback is set.", | |
| (unsigned int)*byte); | |
| /* | |
| * Coalesce with previous run if adjacent LCNs. | |
| * Otherwise, append a new run. | |
| */ | |
| ntfs_debug("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.", | |
| (unsigned long long)(lcn + bmp_pos), | |
| 1ULL, (unsigned long long)prev_lcn, | |
| (unsigned long long)lcn, | |
| (unsigned long long)bmp_pos, | |
| (unsigned long long)prev_run_len, | |
| rlpos); | |
| if (prev_lcn == lcn + bmp_pos - prev_run_len && rlpos) { | |
| ntfs_debug("Coalescing to run (lcn 0x%llx, " | |
| "len 0x%llx).", | |
| (unsigned long long) | |
| rl[rlpos - 1].lcn, | |
| (unsigned long long) | |
| rl[rlpos - 1].length); | |
| rl[rlpos - 1].length = ++prev_run_len; | |
| ntfs_debug("Run now (lcn 0x%llx, len 0x%llx), " | |
| "prev_run_len 0x%llx.", | |
| (unsigned long long) | |
| rl[rlpos - 1].lcn, | |
| (unsigned long long) | |
| rl[rlpos - 1].length, | |
| (unsigned long long) | |
| prev_run_len); | |
| } else { | |
| if (likely(rlpos)) { | |
| ntfs_debug("Adding new run, (previous " | |
| "run lcn 0x%llx, " | |
| "len 0x%llx).", | |
| (unsigned long long) | |
| rl[rlpos - 1].lcn, | |
| (unsigned long long) | |
| rl[rlpos - 1].length); | |
| rl[rlpos].vcn = rl[rlpos - 1].vcn + | |
| prev_run_len; | |
| } else { | |
| ntfs_debug("Adding new run, is first " | |
| "run."); | |
| rl[rlpos].vcn = start_vcn; | |
| } | |
| rl[rlpos].lcn = prev_lcn = lcn + bmp_pos; | |
| rl[rlpos].length = prev_run_len = 1; | |
| rlpos++; | |
| } | |
| /* Done? */ | |
| if (!--clusters) { | |
| LCN tc; | |
| /* | |
| * Update the current zone position. Positions | |
| * of already scanned zones have been updated | |
| * during the respective zone switches. | |
| */ | |
| tc = lcn + bmp_pos + 1; | |
| ntfs_debug("Done. Updating current zone " | |
| "position, tc 0x%llx, " | |
| "search_zone %i.", | |
| (unsigned long long)tc, | |
| search_zone); | |
| switch (search_zone) { | |
| case 1: | |
| ntfs_debug("Before checks, " | |
| "vol->mft_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->mft_zone_pos); | |
| if (tc >= vol->mft_zone_end) { | |
| vol->mft_zone_pos = | |
| vol->mft_lcn; | |
| if (!vol->mft_zone_end) | |
| vol->mft_zone_pos = 0; | |
| } else if ((bmp_initial_pos >= | |
| vol->mft_zone_pos || | |
| tc > vol->mft_zone_pos) | |
| && tc >= vol->mft_lcn) | |
| vol->mft_zone_pos = tc; | |
| ntfs_debug("After checks, " | |
| "vol->mft_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->mft_zone_pos); | |
| break; | |
| case 2: | |
| ntfs_debug("Before checks, " | |
| "vol->data1_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->data1_zone_pos); | |
| if (tc >= vol->nr_clusters) | |
| vol->data1_zone_pos = | |
| vol->mft_zone_end; | |
| else if ((bmp_initial_pos >= | |
| vol->data1_zone_pos || | |
| tc > vol->data1_zone_pos) | |
| && tc >= vol->mft_zone_end) | |
| vol->data1_zone_pos = tc; | |
| ntfs_debug("After checks, " | |
| "vol->data1_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->data1_zone_pos); | |
| break; | |
| case 4: | |
| ntfs_debug("Before checks, " | |
| "vol->data2_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->data2_zone_pos); | |
| if (tc >= vol->mft_zone_start) | |
| vol->data2_zone_pos = 0; | |
| else if (bmp_initial_pos >= | |
| vol->data2_zone_pos || | |
| tc > vol->data2_zone_pos) | |
| vol->data2_zone_pos = tc; | |
| ntfs_debug("After checks, " | |
| "vol->data2_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->data2_zone_pos); | |
| break; | |
| default: | |
| BUG(); | |
| } | |
| ntfs_debug("Finished. Going to out."); | |
| goto out; | |
| } | |
| lcn++; | |
| } | |
| bmp_pos += buf_size; | |
| ntfs_debug("After inner while loop: buf_size 0x%x, lcn " | |
| "0x%llx, bmp_pos 0x%llx, need_writeback %i.", | |
| buf_size, (unsigned long long)lcn, | |
| (unsigned long long)bmp_pos, need_writeback); | |
| if (bmp_pos < zone_end) { | |
| ntfs_debug("Continuing outer while loop, " | |
| "bmp_pos 0x%llx, zone_end 0x%llx.", | |
| (unsigned long long)bmp_pos, | |
| (unsigned long long)zone_end); | |
| continue; | |
| } | |
| zone_pass_done: /* Finished with the current zone pass. */ | |
| ntfs_debug("At zone_pass_done, pass %i.", 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: | |
| BUG(); | |
| } | |
| /* Sanity check. */ | |
| if (zone_end < zone_start) | |
| zone_end = zone_start; | |
| bmp_pos = zone_start; | |
| ntfs_debug("Continuing outer while loop, pass 2, " | |
| "zone_start 0x%llx, zone_end 0x%llx, " | |
| "bmp_pos 0x%llx.", | |
| (unsigned long long)zone_start, | |
| (unsigned long long)zone_end, | |
| (unsigned long long)bmp_pos); | |
| continue; | |
| } /* pass == 2 */ | |
| done_zones_check: | |
| ntfs_debug("At done_zones_check, search_zone %i, done_zones " | |
| "before 0x%x, done_zones after 0x%x.", | |
| search_zone, done_zones, | |
| done_zones | search_zone); | |
| done_zones |= search_zone; | |
| if (done_zones < 7) { | |
| ntfs_debug("Switching zone."); | |
| /* Now switch to the next zone we haven't done yet. */ | |
| pass = 1; | |
| switch (search_zone) { | |
| case 1: | |
| ntfs_debug("Switching from mft zone to data1 " | |
| "zone."); | |
| /* Update mft zone position. */ | |
| if (rlpos) { | |
| LCN tc; | |
| ntfs_debug("Before checks, " | |
| "vol->mft_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->mft_zone_pos); | |
| tc = rl[rlpos - 1].lcn + | |
| rl[rlpos - 1].length; | |
| if (tc >= vol->mft_zone_end) { | |
| vol->mft_zone_pos = | |
| vol->mft_lcn; | |
| if (!vol->mft_zone_end) | |
| vol->mft_zone_pos = 0; | |
| } else if ((bmp_initial_pos >= | |
| vol->mft_zone_pos || | |
| tc > vol->mft_zone_pos) | |
| && tc >= vol->mft_lcn) | |
| vol->mft_zone_pos = tc; | |
| ntfs_debug("After checks, " | |
| "vol->mft_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->mft_zone_pos); | |
| } | |
| /* Switch from mft zone to data1 zone. */ | |
| 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_debug("Switching from data1 zone to " | |
| "data2 zone."); | |
| /* Update data1 zone position. */ | |
| if (rlpos) { | |
| LCN tc; | |
| ntfs_debug("Before checks, " | |
| "vol->data1_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->data1_zone_pos); | |
| tc = rl[rlpos - 1].lcn + | |
| rl[rlpos - 1].length; | |
| if (tc >= vol->nr_clusters) | |
| vol->data1_zone_pos = | |
| vol->mft_zone_end; | |
| else if ((bmp_initial_pos >= | |
| vol->data1_zone_pos || | |
| tc > vol->data1_zone_pos) | |
| && tc >= vol->mft_zone_end) | |
| vol->data1_zone_pos = tc; | |
| ntfs_debug("After checks, " | |
| "vol->data1_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->data1_zone_pos); | |
| } | |
| /* Switch from data1 zone to data2 zone. */ | |
| 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_debug("Switching from data2 zone to " | |
| "data1 zone."); | |
| /* Update data2 zone position. */ | |
| if (rlpos) { | |
| LCN tc; | |
| ntfs_debug("Before checks, " | |
| "vol->data2_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->data2_zone_pos); | |
| tc = rl[rlpos - 1].lcn + | |
| rl[rlpos - 1].length; | |
| if (tc >= vol->mft_zone_start) | |
| vol->data2_zone_pos = 0; | |
| else if (bmp_initial_pos >= | |
| vol->data2_zone_pos || | |
| tc > vol->data2_zone_pos) | |
| vol->data2_zone_pos = tc; | |
| ntfs_debug("After checks, " | |
| "vol->data2_zone_pos " | |
| "0x%llx.", | |
| (unsigned long long) | |
| vol->data2_zone_pos); | |
| } | |
| /* Switch from data2 zone to data1 zone. */ | |
| goto switch_to_data1_zone; | |
| default: | |
| BUG(); | |
| } | |
| ntfs_debug("After zone switch, search_zone %i, " | |
| "pass %i, bmp_initial_pos 0x%llx, " | |
| "zone_start 0x%llx, zone_end 0x%llx.", | |
| search_zone, pass, | |
| (unsigned long long)bmp_initial_pos, | |
| (unsigned long long)zone_start, | |
| (unsigned long long)zone_end); | |
| bmp_pos = zone_start; | |
| if (zone_start == zone_end) { | |
| ntfs_debug("Empty zone, going to " | |
| "done_zones_check."); | |
| /* Empty zone. Don't bother searching it. */ | |
| goto done_zones_check; | |
| } | |
| ntfs_debug("Continuing outer while loop."); | |
| continue; | |
| } /* done_zones == 7 */ | |
| ntfs_debug("All zones are finished."); | |
| /* | |
| * 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_debug("vol->mft_zone_start 0x%llx, vol->mft_zone_end " | |
| "0x%llx, mft_zone_size 0x%llx.", | |
| (unsigned long long)vol->mft_zone_start, | |
| (unsigned long long)vol->mft_zone_end, | |
| (unsigned long long)mft_zone_size); | |
| if (zone == MFT_ZONE || mft_zone_size <= 0) { | |
| ntfs_debug("No free clusters left, going to out."); | |
| /* Really no more space left on device. */ | |
| err = -ENOSPC; | |
| goto out; | |
| } /* zone == DATA_ZONE && mft_zone_size > 0 */ | |
| ntfs_debug("Shrinking mft zone."); | |
| 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_debug("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.", | |
| (unsigned long long)mft_zone_size, | |
| (unsigned long long)vol->mft_zone_start, | |
| (unsigned long long)vol->mft_zone_end, | |
| (unsigned long long)vol->mft_zone_pos, | |
| done_zones, (unsigned long long)zone_start, | |
| (unsigned long long)zone_end, | |
| (unsigned long long)vol->data1_zone_pos); | |
| } | |
| ntfs_debug("After outer while loop."); | |
| out: | |
| ntfs_debug("At out."); | |
| /* Add runlist terminator element. */ | |
| if (likely(rl)) { | |
| rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length; | |
| rl[rlpos].lcn = is_extension ? LCN_ENOENT : LCN_RL_NOT_MAPPED; | |
| rl[rlpos].length = 0; | |
| } | |
| if (likely(page && !IS_ERR(page))) { | |
| if (need_writeback) { | |
| ntfs_debug("Marking page dirty."); | |
| flush_dcache_page(page); | |
| set_page_dirty(page); | |
| need_writeback = 0; | |
| } | |
| ntfs_unmap_page(page); | |
| } | |
| if (likely(!err)) { | |
| up_write(&vol->lcnbmp_lock); | |
| ntfs_debug("Done."); | |
| return rl; | |
| } | |
| ntfs_error(vol->sb, "Failed to allocate clusters, aborting " | |
| "(error %i).", err); | |
| if (rl) { | |
| int err2; | |
| if (err == -ENOSPC) | |
| ntfs_debug("Not enough space to complete allocation, " | |
| "err -ENOSPC, first free lcn 0x%llx, " | |
| "could allocate up to 0x%llx " | |
| "clusters.", | |
| (unsigned long long)rl[0].lcn, | |
| (unsigned long long)(count - clusters)); | |
| /* Deallocate all allocated clusters. */ | |
| ntfs_debug("Attempting rollback..."); | |
| err2 = ntfs_cluster_free_from_rl_nolock(vol, rl); | |
| if (err2) { | |
| ntfs_error(vol->sb, "Failed to rollback (error %i). " | |
| "Leaving inconsistent metadata! " | |
| "Unmount and run chkdsk.", err2); | |
| NVolSetErrors(vol); | |
| } | |
| /* Free the runlist. */ | |
| ntfs_free(rl); | |
| } else if (err == -ENOSPC) | |
| ntfs_debug("No space left at all, err = -ENOSPC, first free " | |
| "lcn = 0x%llx.", | |
| (long long)vol->data1_zone_pos); | |
| up_write(&vol->lcnbmp_lock); | |
| return ERR_PTR(err); | |
| } | |
| /** | |
| * __ntfs_cluster_free - free clusters on an ntfs volume | |
| * @ni: ntfs inode whose runlist describes the clusters to free | |
| * @start_vcn: vcn in the runlist of @ni at which to start freeing clusters | |
| * @count: number of clusters to free or -1 for all clusters | |
| * @ctx: active attribute search context if present or NULL if not | |
| * @is_rollback: true if this is a rollback operation | |
| * | |
| * Free @count clusters starting at the cluster @start_vcn in the runlist | |
| * described by the vfs inode @ni. | |
| * | |
| * If @count is -1, all clusters from @start_vcn to the end of the runlist are | |
| * deallocated. Thus, to completely free all clusters in a runlist, use | |
| * @start_vcn = 0 and @count = -1. | |
| * | |
| * If @ctx is specified, it is an active search context of @ni and its base mft | |
| * record. This is needed when __ntfs_cluster_free() encounters unmapped | |
| * runlist fragments and allows their mapping. If you do not have the mft | |
| * record mapped, you can specify @ctx as NULL and __ntfs_cluster_free() will | |
| * perform the necessary mapping and unmapping. | |
| * | |
| * Note, __ntfs_cluster_free() saves the state of @ctx on entry and restores it | |
| * before returning. Thus, @ctx will be left pointing to the same attribute on | |
| * return as on entry. However, the actual pointers in @ctx may point to | |
| * different memory locations on return, so you must remember to reset any | |
| * cached pointers from the @ctx, i.e. after the call to __ntfs_cluster_free(), | |
| * you will probably want to do: | |
| * m = ctx->mrec; | |
| * a = ctx->attr; | |
| * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that | |
| * you cache ctx->mrec in a variable @m of type MFT_RECORD *. | |
| * | |
| * @is_rollback should always be 'false', it is for internal use to rollback | |
| * errors. You probably want to use ntfs_cluster_free() instead. | |
| * | |
| * Note, __ntfs_cluster_free() does not modify the runlist, so you have to | |
| * remove from the runlist or mark sparse the freed runs later. | |
| * | |
| * Return the number of deallocated clusters (not counting sparse ones) on | |
| * success and -errno on error. | |
| * | |
| * WARNING: If @ctx is supplied, regardless of whether success or failure is | |
| * returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx | |
| * is no longer valid, i.e. you need to either call | |
| * ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it. | |
| * In that case PTR_ERR(@ctx->mrec) will give you the error code for | |
| * why the mapping of the old inode failed. | |
| * | |
| * Locking: - The runlist described by @ni must be locked for writing on entry | |
| * and is locked on return. Note the runlist may be modified when | |
| * needed runlist fragments need to be mapped. | |
| * - The volume lcn bitmap must be unlocked on entry and is unlocked | |
| * on return. | |
| * - This function takes the volume lcn bitmap lock for writing and | |
| * modifies the bitmap contents. | |
| * - If @ctx is NULL, the base mft record of @ni must not be mapped on | |
| * entry and it will be left unmapped on return. | |
| * - If @ctx is not NULL, the base mft record must be mapped on entry | |
| * and it will be left mapped on return. | |
| */ | |
| s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, s64 count, | |
| ntfs_attr_search_ctx *ctx, const bool is_rollback) | |
| { | |
| s64 delta, to_free, total_freed, real_freed; | |
| ntfs_volume *vol; | |
| struct inode *lcnbmp_vi; | |
| runlist_element *rl; | |
| int err; | |
| BUG_ON(!ni); | |
| ntfs_debug("Entering for i_ino 0x%lx, start_vcn 0x%llx, count " | |
| "0x%llx.%s", ni->mft_no, (unsigned long long)start_vcn, | |
| (unsigned long long)count, | |
| is_rollback ? " (rollback)" : ""); | |
| vol = ni->vol; | |
| lcnbmp_vi = vol->lcnbmp_ino; | |
| BUG_ON(!lcnbmp_vi); | |
| BUG_ON(start_vcn < 0); | |
| BUG_ON(count < -1); | |
| /* | |
| * Lock the lcn bitmap for writing but only if not rolling back. We | |
| * must hold the lock all the way including through rollback otherwise | |
| * rollback is not possible because once we have cleared a bit and | |
| * dropped the lock, anyone could have set the bit again, thus | |
| * allocating the cluster for another use. | |
| */ | |
| if (likely(!is_rollback)) | |
| down_write(&vol->lcnbmp_lock); | |
| total_freed = real_freed = 0; | |
| rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, ctx); | |
| if (IS_ERR(rl)) { | |
| if (!is_rollback) | |
| ntfs_error(vol->sb, "Failed to find first runlist " | |
| "element (error %li), aborting.", | |
| PTR_ERR(rl)); | |
| err = PTR_ERR(rl); | |
| goto err_out; | |
| } | |
| if (unlikely(rl->lcn < LCN_HOLE)) { | |
| if (!is_rollback) | |
| ntfs_error(vol->sb, "First runlist element has " | |
| "invalid lcn, aborting."); | |
| err = -EIO; | |
| goto err_out; | |
| } | |
| /* 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 (likely(rl->lcn >= 0)) { | |
| /* Do the actual freeing of the clusters in this run. */ | |
| err = ntfs_bitmap_set_bits_in_run(lcnbmp_vi, rl->lcn + delta, | |
| to_free, likely(!is_rollback) ? 0 : 1); | |
| if (unlikely(err)) { | |
| if (!is_rollback) | |
| ntfs_error(vol->sb, "Failed to clear first run " | |
| "(error %i), aborting.", err); | |
| goto err_out; | |
| } | |
| /* We have freed @to_free real clusters. */ | |
| real_freed = to_free; | |
| }; | |
| /* Go to the next run and adjust the number of clusters left to free. */ | |
| ++rl; | |
| if (count >= 0) | |
| count -= to_free; | |
| /* Keep track of the total "freed" clusters, including sparse ones. */ | |
| total_freed = to_free; | |
| /* | |
| * Loop over the remaining runs, using @count as a capping value, and | |
| * free them. | |
| */ | |
| for (; rl->length && count != 0; ++rl) { | |
| if (unlikely(rl->lcn < LCN_HOLE)) { | |
| VCN vcn; | |
| /* Attempt to map runlist. */ | |
| vcn = rl->vcn; | |
| rl = ntfs_attr_find_vcn_nolock(ni, vcn, ctx); | |
| if (IS_ERR(rl)) { | |
| err = PTR_ERR(rl); | |
| if (!is_rollback) | |
| ntfs_error(vol->sb, "Failed to map " | |
| "runlist fragment or " | |
| "failed to find " | |
| "subsequent runlist " | |
| "element."); | |
| goto err_out; | |
| } | |
| if (unlikely(rl->lcn < LCN_HOLE)) { | |
| if (!is_rollback) | |
| ntfs_error(vol->sb, "Runlist element " | |
| "has invalid lcn " | |
| "(0x%llx).", | |
| (unsigned long long) | |
| rl->lcn); | |
| err = -EIO; | |
| goto err_out; | |
| } | |
| } | |
| /* The number of clusters in this run that need freeing. */ | |
| to_free = rl->length; | |
| if (count >= 0 && to_free > count) | |
| to_free = count; | |
| if (likely(rl->lcn >= 0)) { | |
| /* Do the actual freeing of the clusters in the run. */ | |
| err = ntfs_bitmap_set_bits_in_run(lcnbmp_vi, rl->lcn, | |
| to_free, likely(!is_rollback) ? 0 : 1); | |
| if (unlikely(err)) { | |
| if (!is_rollback) | |
| ntfs_error(vol->sb, "Failed to clear " | |
| "subsequent run."); | |
| goto err_out; | |
| } | |
| /* We have freed @to_free real clusters. */ | |
| real_freed += to_free; | |
| } | |
| /* Adjust the number of clusters left to free. */ | |
| if (count >= 0) | |
| count -= to_free; | |
| /* Update the total done clusters. */ | |
| total_freed += to_free; | |
| } | |
| if (likely(!is_rollback)) | |
| up_write(&vol->lcnbmp_lock); | |
| BUG_ON(count > 0); | |
| /* We are done. Return the number of actually freed clusters. */ | |
| ntfs_debug("Done."); | |
| return real_freed; | |
| err_out: | |
| if (is_rollback) | |
| return err; | |
| /* If no real clusters were freed, no need to rollback. */ | |
| if (!real_freed) { | |
| up_write(&vol->lcnbmp_lock); | |
| return err; | |
| } | |
| /* | |
| * Attempt to rollback and if that succeeds just return the error code. | |
| * If rollback fails, set the volume errors flag, emit an error | |
| * message, and return the error code. | |
| */ | |
| delta = __ntfs_cluster_free(ni, start_vcn, total_freed, ctx, true); | |
| if (delta < 0) { | |
| ntfs_error(vol->sb, "Failed to rollback (error %i). Leaving " | |
| "inconsistent metadata! Unmount and run " | |
| "chkdsk.", (int)delta); | |
| NVolSetErrors(vol); | |
| } | |
| up_write(&vol->lcnbmp_lock); | |
| ntfs_error(vol->sb, "Aborting (error %i).", err); | |
| return err; | |
| } | |
| #endif /* NTFS_RW */ |