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-rw-r--r--fs/ntfs/lcnalloc.c1014
1 files changed, 1014 insertions, 0 deletions
diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c
new file mode 100644
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--- /dev/null
+++ b/fs/ntfs/lcnalloc.c
@@ -0,0 +1,1014 @@
+/*
+ * lcnalloc.c - Cluster (de)allocation code. Part of the Linux-NTFS project.
+ *
+ * Copyright (c) 2004-2005 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.");
+ 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_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 > 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 */
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-13 18:36:41 +0000