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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/ntfs/lcnalloc.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/ntfs/lcnalloc.c')
-rw-r--r-- | fs/ntfs/lcnalloc.c | 1002 |
1 files changed, 1002 insertions, 0 deletions
diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c new file mode 100644 index 0000000..23fd911 --- /dev/null +++ b/fs/ntfs/lcnalloc.c @@ -0,0 +1,1002 @@ +/* + * lcnalloc.c - Cluster (de)allocation code. Part of the Linux-NTFS project. + * + * Copyright (c) 2004 Anton Altaparmakov + * + * 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 Linux-NTFS + * 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 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."); + 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 + * + * 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. + * + * 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) +{ + 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; + 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 empty runlist if @count == 0 */ + // FIXME: Do we want to just return NULL instead? (AIA) + if (!count) { + rl = ntfs_malloc_nofs(PAGE_SIZE); + if (!rl) + return ERR_PTR(-ENOMEM); + rl[0].vcn = start_vcn; + rl[0].lcn = LCN_RL_NOT_MAPPED; + rl[0].length = 0; + return rl; + } + /* 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; + 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 > lcnbmp_vi->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_CACHE_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_CACHE_MASK; + buf = page_address(page) + buf_size; + buf_size = PAGE_CACHE_SIZE - buf_size; + if (unlikely(last_read_pos + buf_size > lcnbmp_vi->i_size)) + buf_size = lcnbmp_vi->i_size - last_read_pos; + buf_size <<= 3; + lcn = bmp_pos & 7; + bmp_pos &= ~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) & ~7; + ntfs_debug("Continuing while loop 1."); + continue; + } + bit = 1 << (lcn & 7); + ntfs_debug("bit %i.", 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 = 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.", + (unsigned long long)vol->data1_zone_pos); + up_write(&vol->lcnbmp_lock); + return ERR_PTR(err); +} + +/** + * __ntfs_cluster_free - free clusters on an ntfs volume + * @vi: vfs inode whose runlist describes the clusters to free + * @start_vcn: vcn in the runlist of @vi at which to start freeing clusters + * @count: number of clusters to free or -1 for all clusters + * @is_rollback: if TRUE this is a rollback operation + * + * Free @count clusters starting at the cluster @start_vcn in the runlist + * described by the vfs inode @vi. + * + * 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. + * + * @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 at all, so the caller + * has to deal with it later. + * + * Return the number of deallocated clusters (not counting sparse ones) on + * success and -errno on error. + * + * Locking: - The runlist described by @vi must be unlocked on entry and is + * unlocked on return. + * - This function takes the runlist lock of @vi for reading and + * sometimes for writing and sometimes modifies the runlist. + * - 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. + */ +s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count, + const BOOL is_rollback) +{ + s64 delta, to_free, total_freed, real_freed; + ntfs_inode *ni; + ntfs_volume *vol; + struct inode *lcnbmp_vi; + runlist_element *rl; + int err; + + BUG_ON(!vi); + ntfs_debug("Entering for i_ino 0x%lx, start_vcn 0x%llx, count " + "0x%llx.%s", vi->i_ino, (unsigned long long)start_vcn, + (unsigned long long)count, + is_rollback ? " (rollback)" : ""); + ni = NTFS_I(vi); + 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; + + /* This returns with ni->runlist locked for reading on success. */ + rl = ntfs_find_vcn(ni, start_vcn, FALSE); + 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 unl_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 unl_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, dropping runlist lock for + * the duration. + */ + vcn = rl->vcn; + up_read(&ni->runlist.lock); + err = ntfs_map_runlist(ni, vcn); + if (err) { + if (!is_rollback) + ntfs_error(vol->sb, "Failed to map " + "runlist fragment."); + if (err == -EINVAL || err == -ENOENT) + err = -EIO; + goto err_out; + } + /* + * This returns with ni->runlist locked for reading on + * success. + */ + rl = ntfs_find_vcn(ni, vcn, FALSE); + if (IS_ERR(rl)) { + err = PTR_ERR(rl); + if (!is_rollback) + ntfs_error(vol->sb, "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 unl_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 unl_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; + } + up_read(&ni->runlist.lock); + 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; +unl_err_out: + up_read(&ni->runlist.lock); +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(vi, start_vcn, total_freed, 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 */ |