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-rw-r--r--fs/ntfs3/run.c1186
1 files changed, 1186 insertions, 0 deletions
diff --git a/fs/ntfs3/run.c b/fs/ntfs3/run.c
new file mode 100644
index 000000000..12d8682f3
--- /dev/null
+++ b/fs/ntfs3/run.c
@@ -0,0 +1,1186 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
+ *
+ * TODO: try to use extents tree (instead of array)
+ */
+
+#include <linux/blkdev.h>
+#include <linux/fs.h>
+#include <linux/log2.h>
+
+#include "debug.h"
+#include "ntfs.h"
+#include "ntfs_fs.h"
+
+/* runs_tree is a continues memory. Try to avoid big size. */
+#define NTFS3_RUN_MAX_BYTES 0x10000
+
+struct ntfs_run {
+ CLST vcn; /* Virtual cluster number. */
+ CLST len; /* Length in clusters. */
+ CLST lcn; /* Logical cluster number. */
+};
+
+/*
+ * run_lookup - Lookup the index of a MCB entry that is first <= vcn.
+ *
+ * Case of success it will return non-zero value and set
+ * @index parameter to index of entry been found.
+ * Case of entry missing from list 'index' will be set to
+ * point to insertion position for the entry question.
+ */
+static bool run_lookup(const struct runs_tree *run, CLST vcn, size_t *index)
+{
+ size_t min_idx, max_idx, mid_idx;
+ struct ntfs_run *r;
+
+ if (!run->count) {
+ *index = 0;
+ return false;
+ }
+
+ min_idx = 0;
+ max_idx = run->count - 1;
+
+ /* Check boundary cases specially, 'cause they cover the often requests. */
+ r = run->runs;
+ if (vcn < r->vcn) {
+ *index = 0;
+ return false;
+ }
+
+ if (vcn < r->vcn + r->len) {
+ *index = 0;
+ return true;
+ }
+
+ r += max_idx;
+ if (vcn >= r->vcn + r->len) {
+ *index = run->count;
+ return false;
+ }
+
+ if (vcn >= r->vcn) {
+ *index = max_idx;
+ return true;
+ }
+
+ do {
+ mid_idx = min_idx + ((max_idx - min_idx) >> 1);
+ r = run->runs + mid_idx;
+
+ if (vcn < r->vcn) {
+ max_idx = mid_idx - 1;
+ if (!mid_idx)
+ break;
+ } else if (vcn >= r->vcn + r->len) {
+ min_idx = mid_idx + 1;
+ } else {
+ *index = mid_idx;
+ return true;
+ }
+ } while (min_idx <= max_idx);
+
+ *index = max_idx + 1;
+ return false;
+}
+
+/*
+ * run_consolidate - Consolidate runs starting from a given one.
+ */
+static void run_consolidate(struct runs_tree *run, size_t index)
+{
+ size_t i;
+ struct ntfs_run *r = run->runs + index;
+
+ while (index + 1 < run->count) {
+ /*
+ * I should merge current run with next
+ * if start of the next run lies inside one being tested.
+ */
+ struct ntfs_run *n = r + 1;
+ CLST end = r->vcn + r->len;
+ CLST dl;
+
+ /* Stop if runs are not aligned one to another. */
+ if (n->vcn > end)
+ break;
+
+ dl = end - n->vcn;
+
+ /*
+ * If range at index overlaps with next one
+ * then I will either adjust it's start position
+ * or (if completely matches) dust remove one from the list.
+ */
+ if (dl > 0) {
+ if (n->len <= dl)
+ goto remove_next_range;
+
+ n->len -= dl;
+ n->vcn += dl;
+ if (n->lcn != SPARSE_LCN)
+ n->lcn += dl;
+ dl = 0;
+ }
+
+ /*
+ * Stop if sparse mode does not match
+ * both current and next runs.
+ */
+ if ((n->lcn == SPARSE_LCN) != (r->lcn == SPARSE_LCN)) {
+ index += 1;
+ r = n;
+ continue;
+ }
+
+ /*
+ * Check if volume block
+ * of a next run lcn does not match
+ * last volume block of the current run.
+ */
+ if (n->lcn != SPARSE_LCN && n->lcn != r->lcn + r->len)
+ break;
+
+ /*
+ * Next and current are siblings.
+ * Eat/join.
+ */
+ r->len += n->len - dl;
+
+remove_next_range:
+ i = run->count - (index + 1);
+ if (i > 1)
+ memmove(n, n + 1, sizeof(*n) * (i - 1));
+
+ run->count -= 1;
+ }
+}
+
+/*
+ * run_is_mapped_full
+ *
+ * Return: True if range [svcn - evcn] is mapped.
+ */
+bool run_is_mapped_full(const struct runs_tree *run, CLST svcn, CLST evcn)
+{
+ size_t i;
+ const struct ntfs_run *r, *end;
+ CLST next_vcn;
+
+ if (!run_lookup(run, svcn, &i))
+ return false;
+
+ end = run->runs + run->count;
+ r = run->runs + i;
+
+ for (;;) {
+ next_vcn = r->vcn + r->len;
+ if (next_vcn > evcn)
+ return true;
+
+ if (++r >= end)
+ return false;
+
+ if (r->vcn != next_vcn)
+ return false;
+ }
+}
+
+bool run_lookup_entry(const struct runs_tree *run, CLST vcn, CLST *lcn,
+ CLST *len, size_t *index)
+{
+ size_t idx;
+ CLST gap;
+ struct ntfs_run *r;
+
+ /* Fail immediately if nrun was not touched yet. */
+ if (!run->runs)
+ return false;
+
+ if (!run_lookup(run, vcn, &idx))
+ return false;
+
+ r = run->runs + idx;
+
+ if (vcn >= r->vcn + r->len)
+ return false;
+
+ gap = vcn - r->vcn;
+ if (r->len <= gap)
+ return false;
+
+ *lcn = r->lcn == SPARSE_LCN ? SPARSE_LCN : (r->lcn + gap);
+
+ if (len)
+ *len = r->len - gap;
+ if (index)
+ *index = idx;
+
+ return true;
+}
+
+/*
+ * run_truncate_head - Decommit the range before vcn.
+ */
+void run_truncate_head(struct runs_tree *run, CLST vcn)
+{
+ size_t index;
+ struct ntfs_run *r;
+
+ if (run_lookup(run, vcn, &index)) {
+ r = run->runs + index;
+
+ if (vcn > r->vcn) {
+ CLST dlen = vcn - r->vcn;
+
+ r->vcn = vcn;
+ r->len -= dlen;
+ if (r->lcn != SPARSE_LCN)
+ r->lcn += dlen;
+ }
+
+ if (!index)
+ return;
+ }
+ r = run->runs;
+ memmove(r, r + index, sizeof(*r) * (run->count - index));
+
+ run->count -= index;
+
+ if (!run->count) {
+ kvfree(run->runs);
+ run->runs = NULL;
+ run->allocated = 0;
+ }
+}
+
+/*
+ * run_truncate - Decommit the range after vcn.
+ */
+void run_truncate(struct runs_tree *run, CLST vcn)
+{
+ size_t index;
+
+ /*
+ * If I hit the range then
+ * I have to truncate one.
+ * If range to be truncated is becoming empty
+ * then it will entirely be removed.
+ */
+ if (run_lookup(run, vcn, &index)) {
+ struct ntfs_run *r = run->runs + index;
+
+ r->len = vcn - r->vcn;
+
+ if (r->len > 0)
+ index += 1;
+ }
+
+ /*
+ * At this point 'index' is set to position that
+ * should be thrown away (including index itself)
+ * Simple one - just set the limit.
+ */
+ run->count = index;
+
+ /* Do not reallocate array 'runs'. Only free if possible. */
+ if (!index) {
+ kvfree(run->runs);
+ run->runs = NULL;
+ run->allocated = 0;
+ }
+}
+
+/*
+ * run_truncate_around - Trim head and tail if necessary.
+ */
+void run_truncate_around(struct runs_tree *run, CLST vcn)
+{
+ run_truncate_head(run, vcn);
+
+ if (run->count >= NTFS3_RUN_MAX_BYTES / sizeof(struct ntfs_run) / 2)
+ run_truncate(run, (run->runs + (run->count >> 1))->vcn);
+}
+
+/*
+ * run_add_entry
+ *
+ * Sets location to known state.
+ * Run to be added may overlap with existing location.
+ *
+ * Return: false if of memory.
+ */
+bool run_add_entry(struct runs_tree *run, CLST vcn, CLST lcn, CLST len,
+ bool is_mft)
+{
+ size_t used, index;
+ struct ntfs_run *r;
+ bool inrange;
+ CLST tail_vcn = 0, tail_len = 0, tail_lcn = 0;
+ bool should_add_tail = false;
+
+ /*
+ * Lookup the insertion point.
+ *
+ * Execute bsearch for the entry containing
+ * start position question.
+ */
+ inrange = run_lookup(run, vcn, &index);
+
+ /*
+ * Shortcut here would be case of
+ * range not been found but one been added
+ * continues previous run.
+ * This case I can directly make use of
+ * existing range as my start point.
+ */
+ if (!inrange && index > 0) {
+ struct ntfs_run *t = run->runs + index - 1;
+
+ if (t->vcn + t->len == vcn &&
+ (t->lcn == SPARSE_LCN) == (lcn == SPARSE_LCN) &&
+ (lcn == SPARSE_LCN || lcn == t->lcn + t->len)) {
+ inrange = true;
+ index -= 1;
+ }
+ }
+
+ /*
+ * At this point 'index' either points to the range
+ * containing start position or to the insertion position
+ * for a new range.
+ * So first let's check if range I'm probing is here already.
+ */
+ if (!inrange) {
+requires_new_range:
+ /*
+ * Range was not found.
+ * Insert at position 'index'
+ */
+ used = run->count * sizeof(struct ntfs_run);
+
+ /*
+ * Check allocated space.
+ * If one is not enough to get one more entry
+ * then it will be reallocated.
+ */
+ if (run->allocated < used + sizeof(struct ntfs_run)) {
+ size_t bytes;
+ struct ntfs_run *new_ptr;
+
+ /* Use power of 2 for 'bytes'. */
+ if (!used) {
+ bytes = 64;
+ } else if (used <= 16 * PAGE_SIZE) {
+ if (is_power_of_2(run->allocated))
+ bytes = run->allocated << 1;
+ else
+ bytes = (size_t)1
+ << (2 + blksize_bits(used));
+ } else {
+ bytes = run->allocated + (16 * PAGE_SIZE);
+ }
+
+ WARN_ON(!is_mft && bytes > NTFS3_RUN_MAX_BYTES);
+
+ new_ptr = kvmalloc(bytes, GFP_KERNEL);
+
+ if (!new_ptr)
+ return false;
+
+ r = new_ptr + index;
+ memcpy(new_ptr, run->runs,
+ index * sizeof(struct ntfs_run));
+ memcpy(r + 1, run->runs + index,
+ sizeof(struct ntfs_run) * (run->count - index));
+
+ kvfree(run->runs);
+ run->runs = new_ptr;
+ run->allocated = bytes;
+
+ } else {
+ size_t i = run->count - index;
+
+ r = run->runs + index;
+
+ /* memmove appears to be a bottle neck here... */
+ if (i > 0)
+ memmove(r + 1, r, sizeof(struct ntfs_run) * i);
+ }
+
+ r->vcn = vcn;
+ r->lcn = lcn;
+ r->len = len;
+ run->count += 1;
+ } else {
+ r = run->runs + index;
+
+ /*
+ * If one of ranges was not allocated then we
+ * have to split location we just matched and
+ * insert current one.
+ * A common case this requires tail to be reinserted
+ * a recursive call.
+ */
+ if (((lcn == SPARSE_LCN) != (r->lcn == SPARSE_LCN)) ||
+ (lcn != SPARSE_LCN && lcn != r->lcn + (vcn - r->vcn))) {
+ CLST to_eat = vcn - r->vcn;
+ CLST Tovcn = to_eat + len;
+
+ should_add_tail = Tovcn < r->len;
+
+ if (should_add_tail) {
+ tail_lcn = r->lcn == SPARSE_LCN
+ ? SPARSE_LCN
+ : (r->lcn + Tovcn);
+ tail_vcn = r->vcn + Tovcn;
+ tail_len = r->len - Tovcn;
+ }
+
+ if (to_eat > 0) {
+ r->len = to_eat;
+ inrange = false;
+ index += 1;
+ goto requires_new_range;
+ }
+
+ /* lcn should match one were going to add. */
+ r->lcn = lcn;
+ }
+
+ /*
+ * If existing range fits then were done.
+ * Otherwise extend found one and fall back to range jocode.
+ */
+ if (r->vcn + r->len < vcn + len)
+ r->len += len - ((r->vcn + r->len) - vcn);
+ }
+
+ /*
+ * And normalize it starting from insertion point.
+ * It's possible that no insertion needed case if
+ * start point lies within the range of an entry
+ * that 'index' points to.
+ */
+ if (inrange && index > 0)
+ index -= 1;
+ run_consolidate(run, index);
+ run_consolidate(run, index + 1);
+
+ /*
+ * A special case.
+ * We have to add extra range a tail.
+ */
+ if (should_add_tail &&
+ !run_add_entry(run, tail_vcn, tail_lcn, tail_len, is_mft))
+ return false;
+
+ return true;
+}
+
+/* run_collapse_range
+ *
+ * Helper for attr_collapse_range(),
+ * which is helper for fallocate(collapse_range).
+ */
+bool run_collapse_range(struct runs_tree *run, CLST vcn, CLST len)
+{
+ size_t index, eat;
+ struct ntfs_run *r, *e, *eat_start, *eat_end;
+ CLST end;
+
+ if (WARN_ON(!run_lookup(run, vcn, &index)))
+ return true; /* Should never be here. */
+
+ e = run->runs + run->count;
+ r = run->runs + index;
+ end = vcn + len;
+
+ if (vcn > r->vcn) {
+ if (r->vcn + r->len <= end) {
+ /* Collapse tail of run .*/
+ r->len = vcn - r->vcn;
+ } else if (r->lcn == SPARSE_LCN) {
+ /* Collapse a middle part of sparsed run. */
+ r->len -= len;
+ } else {
+ /* Collapse a middle part of normal run, split. */
+ if (!run_add_entry(run, vcn, SPARSE_LCN, len, false))
+ return false;
+ return run_collapse_range(run, vcn, len);
+ }
+
+ r += 1;
+ }
+
+ eat_start = r;
+ eat_end = r;
+
+ for (; r < e; r++) {
+ CLST d;
+
+ if (r->vcn >= end) {
+ r->vcn -= len;
+ continue;
+ }
+
+ if (r->vcn + r->len <= end) {
+ /* Eat this run. */
+ eat_end = r + 1;
+ continue;
+ }
+
+ d = end - r->vcn;
+ if (r->lcn != SPARSE_LCN)
+ r->lcn += d;
+ r->len -= d;
+ r->vcn -= len - d;
+ }
+
+ eat = eat_end - eat_start;
+ memmove(eat_start, eat_end, (e - eat_end) * sizeof(*r));
+ run->count -= eat;
+
+ return true;
+}
+
+/* run_insert_range
+ *
+ * Helper for attr_insert_range(),
+ * which is helper for fallocate(insert_range).
+ */
+bool run_insert_range(struct runs_tree *run, CLST vcn, CLST len)
+{
+ size_t index;
+ struct ntfs_run *r, *e;
+
+ if (WARN_ON(!run_lookup(run, vcn, &index)))
+ return false; /* Should never be here. */
+
+ e = run->runs + run->count;
+ r = run->runs + index;
+
+ if (vcn > r->vcn)
+ r += 1;
+
+ for (; r < e; r++)
+ r->vcn += len;
+
+ r = run->runs + index;
+
+ if (vcn > r->vcn) {
+ /* split fragment. */
+ CLST len1 = vcn - r->vcn;
+ CLST len2 = r->len - len1;
+ CLST lcn2 = r->lcn == SPARSE_LCN ? SPARSE_LCN : (r->lcn + len1);
+
+ r->len = len1;
+
+ if (!run_add_entry(run, vcn + len, lcn2, len2, false))
+ return false;
+ }
+
+ if (!run_add_entry(run, vcn, SPARSE_LCN, len, false))
+ return false;
+
+ return true;
+}
+
+/*
+ * run_get_entry - Return index-th mapped region.
+ */
+bool run_get_entry(const struct runs_tree *run, size_t index, CLST *vcn,
+ CLST *lcn, CLST *len)
+{
+ const struct ntfs_run *r;
+
+ if (index >= run->count)
+ return false;
+
+ r = run->runs + index;
+
+ if (!r->len)
+ return false;
+
+ if (vcn)
+ *vcn = r->vcn;
+ if (lcn)
+ *lcn = r->lcn;
+ if (len)
+ *len = r->len;
+ return true;
+}
+
+/*
+ * run_packed_size - Calculate the size of packed int64.
+ */
+#ifdef __BIG_ENDIAN
+static inline int run_packed_size(const s64 n)
+{
+ const u8 *p = (const u8 *)&n + sizeof(n) - 1;
+
+ if (n >= 0) {
+ if (p[-7] || p[-6] || p[-5] || p[-4])
+ p -= 4;
+ if (p[-3] || p[-2])
+ p -= 2;
+ if (p[-1])
+ p -= 1;
+ if (p[0] & 0x80)
+ p -= 1;
+ } else {
+ if (p[-7] != 0xff || p[-6] != 0xff || p[-5] != 0xff ||
+ p[-4] != 0xff)
+ p -= 4;
+ if (p[-3] != 0xff || p[-2] != 0xff)
+ p -= 2;
+ if (p[-1] != 0xff)
+ p -= 1;
+ if (!(p[0] & 0x80))
+ p -= 1;
+ }
+ return (const u8 *)&n + sizeof(n) - p;
+}
+
+/* Full trusted function. It does not check 'size' for errors. */
+static inline void run_pack_s64(u8 *run_buf, u8 size, s64 v)
+{
+ const u8 *p = (u8 *)&v;
+
+ switch (size) {
+ case 8:
+ run_buf[7] = p[0];
+ fallthrough;
+ case 7:
+ run_buf[6] = p[1];
+ fallthrough;
+ case 6:
+ run_buf[5] = p[2];
+ fallthrough;
+ case 5:
+ run_buf[4] = p[3];
+ fallthrough;
+ case 4:
+ run_buf[3] = p[4];
+ fallthrough;
+ case 3:
+ run_buf[2] = p[5];
+ fallthrough;
+ case 2:
+ run_buf[1] = p[6];
+ fallthrough;
+ case 1:
+ run_buf[0] = p[7];
+ }
+}
+
+/* Full trusted function. It does not check 'size' for errors. */
+static inline s64 run_unpack_s64(const u8 *run_buf, u8 size, s64 v)
+{
+ u8 *p = (u8 *)&v;
+
+ switch (size) {
+ case 8:
+ p[0] = run_buf[7];
+ fallthrough;
+ case 7:
+ p[1] = run_buf[6];
+ fallthrough;
+ case 6:
+ p[2] = run_buf[5];
+ fallthrough;
+ case 5:
+ p[3] = run_buf[4];
+ fallthrough;
+ case 4:
+ p[4] = run_buf[3];
+ fallthrough;
+ case 3:
+ p[5] = run_buf[2];
+ fallthrough;
+ case 2:
+ p[6] = run_buf[1];
+ fallthrough;
+ case 1:
+ p[7] = run_buf[0];
+ }
+ return v;
+}
+
+#else
+
+static inline int run_packed_size(const s64 n)
+{
+ const u8 *p = (const u8 *)&n;
+
+ if (n >= 0) {
+ if (p[7] || p[6] || p[5] || p[4])
+ p += 4;
+ if (p[3] || p[2])
+ p += 2;
+ if (p[1])
+ p += 1;
+ if (p[0] & 0x80)
+ p += 1;
+ } else {
+ if (p[7] != 0xff || p[6] != 0xff || p[5] != 0xff ||
+ p[4] != 0xff)
+ p += 4;
+ if (p[3] != 0xff || p[2] != 0xff)
+ p += 2;
+ if (p[1] != 0xff)
+ p += 1;
+ if (!(p[0] & 0x80))
+ p += 1;
+ }
+
+ return 1 + p - (const u8 *)&n;
+}
+
+/* Full trusted function. It does not check 'size' for errors. */
+static inline void run_pack_s64(u8 *run_buf, u8 size, s64 v)
+{
+ const u8 *p = (u8 *)&v;
+
+ /* memcpy( run_buf, &v, size); Is it faster? */
+ switch (size) {
+ case 8:
+ run_buf[7] = p[7];
+ fallthrough;
+ case 7:
+ run_buf[6] = p[6];
+ fallthrough;
+ case 6:
+ run_buf[5] = p[5];
+ fallthrough;
+ case 5:
+ run_buf[4] = p[4];
+ fallthrough;
+ case 4:
+ run_buf[3] = p[3];
+ fallthrough;
+ case 3:
+ run_buf[2] = p[2];
+ fallthrough;
+ case 2:
+ run_buf[1] = p[1];
+ fallthrough;
+ case 1:
+ run_buf[0] = p[0];
+ }
+}
+
+/* full trusted function. It does not check 'size' for errors */
+static inline s64 run_unpack_s64(const u8 *run_buf, u8 size, s64 v)
+{
+ u8 *p = (u8 *)&v;
+
+ /* memcpy( &v, run_buf, size); Is it faster? */
+ switch (size) {
+ case 8:
+ p[7] = run_buf[7];
+ fallthrough;
+ case 7:
+ p[6] = run_buf[6];
+ fallthrough;
+ case 6:
+ p[5] = run_buf[5];
+ fallthrough;
+ case 5:
+ p[4] = run_buf[4];
+ fallthrough;
+ case 4:
+ p[3] = run_buf[3];
+ fallthrough;
+ case 3:
+ p[2] = run_buf[2];
+ fallthrough;
+ case 2:
+ p[1] = run_buf[1];
+ fallthrough;
+ case 1:
+ p[0] = run_buf[0];
+ }
+ return v;
+}
+#endif
+
+/*
+ * run_pack - Pack runs into buffer.
+ *
+ * packed_vcns - How much runs we have packed.
+ * packed_size - How much bytes we have used run_buf.
+ */
+int run_pack(const struct runs_tree *run, CLST svcn, CLST len, u8 *run_buf,
+ u32 run_buf_size, CLST *packed_vcns)
+{
+ CLST next_vcn, vcn, lcn;
+ CLST prev_lcn = 0;
+ CLST evcn1 = svcn + len;
+ const struct ntfs_run *r, *r_end;
+ int packed_size = 0;
+ size_t i;
+ s64 dlcn;
+ int offset_size, size_size, tmp;
+
+ *packed_vcns = 0;
+
+ if (!len)
+ goto out;
+
+ /* Check all required entries [svcn, encv1) available. */
+ if (!run_lookup(run, svcn, &i))
+ return -ENOENT;
+
+ r_end = run->runs + run->count;
+ r = run->runs + i;
+
+ for (next_vcn = r->vcn + r->len; next_vcn < evcn1;
+ next_vcn = r->vcn + r->len) {
+ if (++r >= r_end || r->vcn != next_vcn)
+ return -ENOENT;
+ }
+
+ /* Repeat cycle above and pack runs. Assume no errors. */
+ r = run->runs + i;
+ len = svcn - r->vcn;
+ vcn = svcn;
+ lcn = r->lcn == SPARSE_LCN ? SPARSE_LCN : (r->lcn + len);
+ len = r->len - len;
+
+ for (;;) {
+ next_vcn = vcn + len;
+ if (next_vcn > evcn1)
+ len = evcn1 - vcn;
+
+ /* How much bytes required to pack len. */
+ size_size = run_packed_size(len);
+
+ /* offset_size - How much bytes is packed dlcn. */
+ if (lcn == SPARSE_LCN) {
+ offset_size = 0;
+ dlcn = 0;
+ } else {
+ /* NOTE: lcn can be less than prev_lcn! */
+ dlcn = (s64)lcn - prev_lcn;
+ offset_size = run_packed_size(dlcn);
+ prev_lcn = lcn;
+ }
+
+ tmp = run_buf_size - packed_size - 2 - offset_size;
+ if (tmp <= 0)
+ goto out;
+
+ /* Can we store this entire run. */
+ if (tmp < size_size)
+ goto out;
+
+ if (run_buf) {
+ /* Pack run header. */
+ run_buf[0] = ((u8)(size_size | (offset_size << 4)));
+ run_buf += 1;
+
+ /* Pack the length of run. */
+ run_pack_s64(run_buf, size_size, len);
+
+ run_buf += size_size;
+ /* Pack the offset from previous LCN. */
+ run_pack_s64(run_buf, offset_size, dlcn);
+ run_buf += offset_size;
+ }
+
+ packed_size += 1 + offset_size + size_size;
+ *packed_vcns += len;
+
+ if (packed_size + 1 >= run_buf_size || next_vcn >= evcn1)
+ goto out;
+
+ r += 1;
+ vcn = r->vcn;
+ lcn = r->lcn;
+ len = r->len;
+ }
+
+out:
+ /* Store last zero. */
+ if (run_buf)
+ run_buf[0] = 0;
+
+ return packed_size + 1;
+}
+
+/*
+ * run_unpack - Unpack packed runs from @run_buf.
+ *
+ * Return: Error if negative, or real used bytes.
+ */
+int run_unpack(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
+ CLST svcn, CLST evcn, CLST vcn, const u8 *run_buf,
+ int run_buf_size)
+{
+ u64 prev_lcn, vcn64, lcn, next_vcn;
+ const u8 *run_last, *run_0;
+ bool is_mft = ino == MFT_REC_MFT;
+
+ if (run_buf_size < 0)
+ return -EINVAL;
+
+ /* Check for empty. */
+ if (evcn + 1 == svcn)
+ return 0;
+
+ if (evcn < svcn)
+ return -EINVAL;
+
+ run_0 = run_buf;
+ run_last = run_buf + run_buf_size;
+ prev_lcn = 0;
+ vcn64 = svcn;
+
+ /* Read all runs the chain. */
+ /* size_size - How much bytes is packed len. */
+ while (run_buf < run_last) {
+ /* size_size - How much bytes is packed len. */
+ u8 size_size = *run_buf & 0xF;
+ /* offset_size - How much bytes is packed dlcn. */
+ u8 offset_size = *run_buf++ >> 4;
+ u64 len;
+
+ if (!size_size)
+ break;
+
+ /*
+ * Unpack runs.
+ * NOTE: Runs are stored little endian order
+ * "len" is unsigned value, "dlcn" is signed.
+ * Large positive number requires to store 5 bytes
+ * e.g.: 05 FF 7E FF FF 00 00 00
+ */
+ if (size_size > 8)
+ return -EINVAL;
+
+ len = run_unpack_s64(run_buf, size_size, 0);
+ /* Skip size_size. */
+ run_buf += size_size;
+
+ if (!len)
+ return -EINVAL;
+
+ if (!offset_size)
+ lcn = SPARSE_LCN64;
+ else if (offset_size <= 8) {
+ s64 dlcn;
+
+ /* Initial value of dlcn is -1 or 0. */
+ dlcn = (run_buf[offset_size - 1] & 0x80) ? (s64)-1 : 0;
+ dlcn = run_unpack_s64(run_buf, offset_size, dlcn);
+ /* Skip offset_size. */
+ run_buf += offset_size;
+
+ if (!dlcn)
+ return -EINVAL;
+ lcn = prev_lcn + dlcn;
+ prev_lcn = lcn;
+ } else
+ return -EINVAL;
+
+ next_vcn = vcn64 + len;
+ /* Check boundary. */
+ if (next_vcn > evcn + 1)
+ return -EINVAL;
+
+#ifndef CONFIG_NTFS3_64BIT_CLUSTER
+ if (next_vcn > 0x100000000ull || (lcn + len) > 0x100000000ull) {
+ ntfs_err(
+ sbi->sb,
+ "This driver is compiled without CONFIG_NTFS3_64BIT_CLUSTER (like windows driver).\n"
+ "Volume contains 64 bits run: vcn %llx, lcn %llx, len %llx.\n"
+ "Activate CONFIG_NTFS3_64BIT_CLUSTER to process this case",
+ vcn64, lcn, len);
+ return -EOPNOTSUPP;
+ }
+#endif
+ if (lcn != SPARSE_LCN64 && lcn + len > sbi->used.bitmap.nbits) {
+ /* LCN range is out of volume. */
+ return -EINVAL;
+ }
+
+ if (!run)
+ ; /* Called from check_attr(fslog.c) to check run. */
+ else if (run == RUN_DEALLOCATE) {
+ /*
+ * Called from ni_delete_all to free clusters
+ * without storing in run.
+ */
+ if (lcn != SPARSE_LCN64)
+ mark_as_free_ex(sbi, lcn, len, true);
+ } else if (vcn64 >= vcn) {
+ if (!run_add_entry(run, vcn64, lcn, len, is_mft))
+ return -ENOMEM;
+ } else if (next_vcn > vcn) {
+ u64 dlen = vcn - vcn64;
+
+ if (!run_add_entry(run, vcn, lcn + dlen, len - dlen,
+ is_mft))
+ return -ENOMEM;
+ }
+
+ vcn64 = next_vcn;
+ }
+
+ if (vcn64 != evcn + 1) {
+ /* Not expected length of unpacked runs. */
+ return -EINVAL;
+ }
+
+ return run_buf - run_0;
+}
+
+#ifdef NTFS3_CHECK_FREE_CLST
+/*
+ * run_unpack_ex - Unpack packed runs from "run_buf".
+ *
+ * Checks unpacked runs to be used in bitmap.
+ *
+ * Return: Error if negative, or real used bytes.
+ */
+int run_unpack_ex(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
+ CLST svcn, CLST evcn, CLST vcn, const u8 *run_buf,
+ int run_buf_size)
+{
+ int ret, err;
+ CLST next_vcn, lcn, len;
+ size_t index;
+ bool ok;
+ struct wnd_bitmap *wnd;
+
+ ret = run_unpack(run, sbi, ino, svcn, evcn, vcn, run_buf, run_buf_size);
+ if (ret <= 0)
+ return ret;
+
+ if (!sbi->used.bitmap.sb || !run || run == RUN_DEALLOCATE)
+ return ret;
+
+ if (ino == MFT_REC_BADCLUST)
+ return ret;
+
+ next_vcn = vcn = svcn;
+ wnd = &sbi->used.bitmap;
+
+ for (ok = run_lookup_entry(run, vcn, &lcn, &len, &index);
+ next_vcn <= evcn;
+ ok = run_get_entry(run, ++index, &vcn, &lcn, &len)) {
+ if (!ok || next_vcn != vcn)
+ return -EINVAL;
+
+ next_vcn = vcn + len;
+
+ if (lcn == SPARSE_LCN)
+ continue;
+
+ if (sbi->flags & NTFS_FLAGS_NEED_REPLAY)
+ continue;
+
+ down_read_nested(&wnd->rw_lock, BITMAP_MUTEX_CLUSTERS);
+ /* Check for free blocks. */
+ ok = wnd_is_used(wnd, lcn, len);
+ up_read(&wnd->rw_lock);
+ if (ok)
+ continue;
+
+ /* Looks like volume is corrupted. */
+ ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
+
+ if (down_write_trylock(&wnd->rw_lock)) {
+ /* Mark all zero bits as used in range [lcn, lcn+len). */
+ CLST i, lcn_f = 0, len_f = 0;
+
+ err = 0;
+ for (i = 0; i < len; i++) {
+ if (wnd_is_free(wnd, lcn + i, 1)) {
+ if (!len_f)
+ lcn_f = lcn + i;
+ len_f += 1;
+ } else if (len_f) {
+ err = wnd_set_used(wnd, lcn_f, len_f);
+ len_f = 0;
+ if (err)
+ break;
+ }
+ }
+
+ if (len_f)
+ err = wnd_set_used(wnd, lcn_f, len_f);
+
+ up_write(&wnd->rw_lock);
+ if (err)
+ return err;
+ }
+ }
+
+ return ret;
+}
+#endif
+
+/*
+ * run_get_highest_vcn
+ *
+ * Return the highest vcn from a mapping pairs array
+ * it used while replaying log file.
+ */
+int run_get_highest_vcn(CLST vcn, const u8 *run_buf, u64 *highest_vcn)
+{
+ u64 vcn64 = vcn;
+ u8 size_size;
+
+ while ((size_size = *run_buf & 0xF)) {
+ u8 offset_size = *run_buf++ >> 4;
+ u64 len;
+
+ if (size_size > 8 || offset_size > 8)
+ return -EINVAL;
+
+ len = run_unpack_s64(run_buf, size_size, 0);
+ if (!len)
+ return -EINVAL;
+
+ run_buf += size_size + offset_size;
+ vcn64 += len;
+
+#ifndef CONFIG_NTFS3_64BIT_CLUSTER
+ if (vcn64 > 0x100000000ull)
+ return -EINVAL;
+#endif
+ }
+
+ *highest_vcn = vcn64 - 1;
+ return 0;
+}
+
+/*
+ * run_clone
+ *
+ * Make a copy of run
+ */
+int run_clone(const struct runs_tree *run, struct runs_tree *new_run)
+{
+ size_t bytes = run->count * sizeof(struct ntfs_run);
+
+ if (bytes > new_run->allocated) {
+ struct ntfs_run *new_ptr = kvmalloc(bytes, GFP_KERNEL);
+
+ if (!new_ptr)
+ return -ENOMEM;
+
+ kvfree(new_run->runs);
+ new_run->runs = new_ptr;
+ new_run->allocated = bytes;
+ }
+
+ memcpy(new_run->runs, run->runs, bytes);
+ new_run->count = run->count;
+ return 0;
+}