Commit fa3be923 authored by Anton Altaparmakov's avatar Anton Altaparmakov
Browse files

NTFS: Add an extra parameter @last_vcn to ntfs_get_size_for_mapping_pairs()


      and ntfs_mapping_pairs_build() to allow the runlist encoding to be
      partial which is desirable when filling holes in sparse attributes.
      Update all callers.
Signed-off-by: default avatarAnton Altaparmakov <aia21@cantab.net>
parent 1d58b27b
......@@ -135,6 +135,10 @@ ToDo/Notes:
- Change the runlist terminator of the newly allocated cluster(s) to
LCN_ENOENT in ntfs_attr_make_non_resident(). Otherwise the runlist
code gets confused.
- Add an extra parameter @last_vcn to ntfs_get_size_for_mapping_pairs()
and ntfs_mapping_pairs_build() to allow the runlist encoding to be
partial which is desirable when filling holes in sparse attributes.
Update all callers.
2.1.22 - Many bug and race fixes and error handling improvements.
......
......@@ -1317,7 +1317,7 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
page = NULL;
}
/* Determine the size of the mapping pairs array. */
mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0);
mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0, -1);
if (unlikely(mp_size < 0)) {
err = mp_size;
ntfs_debug("Failed to get size for mapping pairs array, error "
......@@ -1416,7 +1416,7 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
cpu_to_sle64(attr_size);
/* Generate the mapping pairs array into the attribute record. */
err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs,
arec_size - mp_ofs, rl, 0, NULL);
arec_size - mp_ofs, rl, 0, -1, NULL);
if (unlikely(err)) {
ntfs_debug("Failed to build mapping pairs, error code %i.",
err);
......
......@@ -1407,7 +1407,7 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol)
BUG_ON(ll < rl2->vcn);
BUG_ON(ll >= rl2->vcn + rl2->length);
/* Get the size for the new mapping pairs array for this extent. */
mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll);
mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1);
if (unlikely(mp_size <= 0)) {
ntfs_error(vol->sb, "Get size for mapping pairs failed for "
"mft bitmap attribute extent.");
......@@ -1441,7 +1441,7 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol)
/* Generate the mapping pairs array directly into the attr record. */
ret = ntfs_mapping_pairs_build(vol, (u8*)a +
le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
mp_size, rl2, ll, NULL);
mp_size, rl2, ll, -1, NULL);
if (unlikely(ret)) {
ntfs_error(vol->sb, "Failed to build mapping pairs array for "
"mft bitmap attribute.");
......@@ -1529,7 +1529,7 @@ undo_alloc:
a->data.non_resident.mapping_pairs_offset),
old_alen - le16_to_cpu(
a->data.non_resident.mapping_pairs_offset),
rl2, ll, NULL)) {
rl2, ll, -1, NULL)) {
ntfs_error(vol->sb, "Failed to restore mapping pairs "
"array.%s", es);
NVolSetErrors(vol);
......@@ -1838,7 +1838,7 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol)
BUG_ON(ll < rl2->vcn);
BUG_ON(ll >= rl2->vcn + rl2->length);
/* Get the size for the new mapping pairs array for this extent. */
mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll);
mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1);
if (unlikely(mp_size <= 0)) {
ntfs_error(vol->sb, "Get size for mapping pairs failed for "
"mft data attribute extent.");
......@@ -1877,7 +1877,7 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol)
/* Generate the mapping pairs array directly into the attr record. */
ret = ntfs_mapping_pairs_build(vol, (u8*)a +
le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
mp_size, rl2, ll, NULL);
mp_size, rl2, ll, -1, NULL);
if (unlikely(ret)) {
ntfs_error(vol->sb, "Failed to build mapping pairs array of "
"mft data attribute.");
......@@ -1959,7 +1959,7 @@ undo_alloc:
a->data.non_resident.mapping_pairs_offset),
old_alen - le16_to_cpu(
a->data.non_resident.mapping_pairs_offset),
rl2, ll, NULL)) {
rl2, ll, -1, NULL)) {
ntfs_error(vol->sb, "Failed to restore mapping pairs "
"array.%s", es);
NVolSetErrors(vol);
......
......@@ -1048,10 +1048,17 @@ static inline int ntfs_get_nr_significant_bytes(const s64 n)
* ntfs_get_size_for_mapping_pairs - get bytes needed for mapping pairs array
* @vol: ntfs volume (needed for the ntfs version)
* @rl: locked runlist to determine the size of the mapping pairs of
* @start_vcn: vcn at which to start the mapping pairs array
* @first_vcn: first vcn which to include in the mapping pairs array
* @last_vcn: last vcn which to include in the mapping pairs array
*
* Walk the locked runlist @rl and calculate the size in bytes of the mapping
* pairs array corresponding to the runlist @rl, starting at vcn @start_vcn.
* pairs array corresponding to the runlist @rl, starting at vcn @first_vcn and
* finishing with vcn @last_vcn.
*
* A @last_vcn of -1 means end of runlist and in that case the size of the
* mapping pairs array corresponding to the runlist starting at vcn @first_vcn
* and finishing at the end of the runlist is determined.
*
* This for example allows us to allocate a buffer of the right size when
* building the mapping pairs array.
*
......@@ -1067,34 +1074,50 @@ static inline int ntfs_get_nr_significant_bytes(const s64 n)
* remains locked throughout, and is left locked upon return.
*/
int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,
const runlist_element *rl, const VCN start_vcn)
const runlist_element *rl, const VCN first_vcn,
const VCN last_vcn)
{
LCN prev_lcn;
int rls;
BOOL the_end = FALSE;
BUG_ON(start_vcn < 0);
BUG_ON(first_vcn < 0);
BUG_ON(last_vcn < -1);
BUG_ON(last_vcn >= 0 && first_vcn > last_vcn);
if (!rl) {
BUG_ON(start_vcn);
BUG_ON(first_vcn);
BUG_ON(last_vcn > 0);
return 1;
}
/* Skip to runlist element containing @start_vcn. */
while (rl->length && start_vcn >= rl[1].vcn)
/* Skip to runlist element containing @first_vcn. */
while (rl->length && first_vcn >= rl[1].vcn)
rl++;
if ((!rl->length && start_vcn > rl->vcn) || start_vcn < rl->vcn)
if (unlikely((!rl->length && first_vcn > rl->vcn) ||
first_vcn < rl->vcn))
return -EINVAL;
prev_lcn = 0;
/* Always need the termining zero byte. */
rls = 1;
/* Do the first partial run if present. */
if (start_vcn > rl->vcn) {
s64 delta;
if (first_vcn > rl->vcn) {
s64 delta, length = rl->length;
/* We know rl->length != 0 already. */
if (rl->length < 0 || rl->lcn < LCN_HOLE)
if (unlikely(length < 0 || rl->lcn < LCN_HOLE))
goto err_out;
delta = start_vcn - rl->vcn;
/*
* If @stop_vcn is given and finishes inside this run, cap the
* run length.
*/
if (unlikely(last_vcn >= 0 && rl[1].vcn > last_vcn)) {
s64 s1 = last_vcn + 1;
if (unlikely(rl[1].vcn > s1))
length = s1 - rl->vcn;
the_end = TRUE;
}
delta = first_vcn - rl->vcn;
/* Header byte + length. */
rls += 1 + ntfs_get_nr_significant_bytes(rl->length - delta);
rls += 1 + ntfs_get_nr_significant_bytes(length - delta);
/*
* If the logical cluster number (lcn) denotes a hole and we
* are on NTFS 3.0+, we don't store it at all, i.e. we need
......@@ -1102,9 +1125,9 @@ int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,
* Note: this assumes that on NTFS 1.2-, holes are stored with
* an lcn of -1 and not a delta_lcn of -1 (unless both are -1).
*/
if (rl->lcn >= 0 || vol->major_ver < 3) {
if (likely(rl->lcn >= 0 || vol->major_ver < 3)) {
prev_lcn = rl->lcn;
if (rl->lcn >= 0)
if (likely(rl->lcn >= 0))
prev_lcn += delta;
/* Change in lcn. */
rls += ntfs_get_nr_significant_bytes(prev_lcn);
......@@ -1113,11 +1136,23 @@ int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,
rl++;
}
/* Do the full runs. */
for (; rl->length; rl++) {
if (rl->length < 0 || rl->lcn < LCN_HOLE)
for (; rl->length && !the_end; rl++) {
s64 length = rl->length;
if (unlikely(length < 0 || rl->lcn < LCN_HOLE))
goto err_out;
/*
* If @stop_vcn is given and finishes inside this run, cap the
* run length.
*/
if (unlikely(last_vcn >= 0 && rl[1].vcn > last_vcn)) {
s64 s1 = last_vcn + 1;
if (unlikely(rl[1].vcn > s1))
length = s1 - rl->vcn;
the_end = TRUE;
}
/* Header byte + length. */
rls += 1 + ntfs_get_nr_significant_bytes(rl->length);
rls += 1 + ntfs_get_nr_significant_bytes(length);
/*
* If the logical cluster number (lcn) denotes a hole and we
* are on NTFS 3.0+, we don't store it at all, i.e. we need
......@@ -1125,7 +1160,7 @@ int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,
* Note: this assumes that on NTFS 1.2-, holes are stored with
* an lcn of -1 and not a delta_lcn of -1 (unless both are -1).
*/
if (rl->lcn >= 0 || vol->major_ver < 3) {
if (likely(rl->lcn >= 0 || vol->major_ver < 3)) {
/* Change in lcn. */
rls += ntfs_get_nr_significant_bytes(rl->lcn -
prev_lcn);
......@@ -1168,7 +1203,7 @@ static inline int ntfs_write_significant_bytes(s8 *dst, const s8 *dst_max,
i = 0;
do {
if (dst > dst_max)
if (unlikely(dst > dst_max))
goto err_out;
*dst++ = l & 0xffll;
l >>= 8;
......@@ -1177,12 +1212,12 @@ static inline int ntfs_write_significant_bytes(s8 *dst, const s8 *dst_max,
j = (n >> 8 * (i - 1)) & 0xff;
/* If the sign bit is wrong, we need an extra byte. */
if (n < 0 && j >= 0) {
if (dst > dst_max)
if (unlikely(dst > dst_max))
goto err_out;
i++;
*dst = (s8)-1;
} else if (n > 0 && j < 0) {
if (dst > dst_max)
if (unlikely(dst > dst_max))
goto err_out;
i++;
*dst = (s8)0;
......@@ -1198,13 +1233,18 @@ err_out:
* @dst: destination buffer to which to write the mapping pairs array
* @dst_len: size of destination buffer @dst in bytes
* @rl: locked runlist for which to build the mapping pairs array
* @start_vcn: vcn at which to start the mapping pairs array
* @first_vcn: first vcn which to include in the mapping pairs array
* @last_vcn: last vcn which to include in the mapping pairs array
* @stop_vcn: first vcn outside destination buffer on success or -ENOSPC
*
* Create the mapping pairs array from the locked runlist @rl, starting at vcn
* @start_vcn and save the array in @dst. @dst_len is the size of @dst in
* bytes and it should be at least equal to the value obtained by calling
* ntfs_get_size_for_mapping_pairs().
* @first_vcn and finishing with vcn @last_vcn and save the array in @dst.
* @dst_len is the size of @dst in bytes and it should be at least equal to the
* value obtained by calling ntfs_get_size_for_mapping_pairs().
*
* A @last_vcn of -1 means end of runlist and in that case the mapping pairs
* array corresponding to the runlist starting at vcn @first_vcn and finishing
* at the end of the runlist is created.
*
* If @rl is NULL, just write a single terminator byte to @dst.
*
......@@ -1213,7 +1253,7 @@ err_out:
* been filled with all the mapping pairs that will fit, thus it can be treated
* as partial success, in that a new attribute extent needs to be created or
* the next extent has to be used and the mapping pairs build has to be
* continued with @start_vcn set to *@stop_vcn.
* continued with @first_vcn set to *@stop_vcn.
*
* Return 0 on success and -errno on error. The following error codes are
* defined:
......@@ -1227,27 +1267,32 @@ err_out:
*/
int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
const int dst_len, const runlist_element *rl,
const VCN start_vcn, VCN *const stop_vcn)
const VCN first_vcn, const VCN last_vcn, VCN *const stop_vcn)
{
LCN prev_lcn;
s8 *dst_max, *dst_next;
int err = -ENOSPC;
BOOL the_end = FALSE;
s8 len_len, lcn_len;
BUG_ON(start_vcn < 0);
BUG_ON(first_vcn < 0);
BUG_ON(last_vcn < -1);
BUG_ON(last_vcn >= 0 && first_vcn > last_vcn);
BUG_ON(dst_len < 1);
if (!rl) {
BUG_ON(start_vcn);
BUG_ON(first_vcn);
BUG_ON(last_vcn > 0);
if (stop_vcn)
*stop_vcn = 0;
/* Terminator byte. */
*dst = 0;
return 0;
}
/* Skip to runlist element containing @start_vcn. */
while (rl->length && start_vcn >= rl[1].vcn)
/* Skip to runlist element containing @first_vcn. */
while (rl->length && first_vcn >= rl[1].vcn)
rl++;
if ((!rl->length && start_vcn > rl->vcn) || start_vcn < rl->vcn)
if (unlikely((!rl->length && first_vcn > rl->vcn) ||
first_vcn < rl->vcn))
return -EINVAL;
/*
* @dst_max is used for bounds checking in
......@@ -1256,17 +1301,27 @@ int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
dst_max = dst + dst_len - 1;
prev_lcn = 0;
/* Do the first partial run if present. */
if (start_vcn > rl->vcn) {
s64 delta;
if (first_vcn > rl->vcn) {
s64 delta, length = rl->length;
/* We know rl->length != 0 already. */
if (rl->length < 0 || rl->lcn < LCN_HOLE)
if (unlikely(length < 0 || rl->lcn < LCN_HOLE))
goto err_out;
delta = start_vcn - rl->vcn;
/*
* If @stop_vcn is given and finishes inside this run, cap the
* run length.
*/
if (unlikely(last_vcn >= 0 && rl[1].vcn > last_vcn)) {
s64 s1 = last_vcn + 1;
if (unlikely(rl[1].vcn > s1))
length = s1 - rl->vcn;
the_end = TRUE;
}
delta = first_vcn - rl->vcn;
/* Write length. */
len_len = ntfs_write_significant_bytes(dst + 1, dst_max,
rl->length - delta);
if (len_len < 0)
length - delta);
if (unlikely(len_len < 0))
goto size_err;
/*
* If the logical cluster number (lcn) denotes a hole and we
......@@ -1277,19 +1332,19 @@ int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
* case on NT4. - We assume that we just need to write the lcn
* change until someone tells us otherwise... (AIA)
*/
if (rl->lcn >= 0 || vol->major_ver < 3) {
if (likely(rl->lcn >= 0 || vol->major_ver < 3)) {
prev_lcn = rl->lcn;
if (rl->lcn >= 0)
if (likely(rl->lcn >= 0))
prev_lcn += delta;
/* Write change in lcn. */
lcn_len = ntfs_write_significant_bytes(dst + 1 +
len_len, dst_max, prev_lcn);
if (lcn_len < 0)
if (unlikely(lcn_len < 0))
goto size_err;
} else
lcn_len = 0;
dst_next = dst + len_len + lcn_len + 1;
if (dst_next > dst_max)
if (unlikely(dst_next > dst_max))
goto size_err;
/* Update header byte. */
*dst = lcn_len << 4 | len_len;
......@@ -1299,13 +1354,25 @@ int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
rl++;
}
/* Do the full runs. */
for (; rl->length; rl++) {
if (rl->length < 0 || rl->lcn < LCN_HOLE)
for (; rl->length && !the_end; rl++) {
s64 length = rl->length;
if (unlikely(length < 0 || rl->lcn < LCN_HOLE))
goto err_out;
/*
* If @stop_vcn is given and finishes inside this run, cap the
* run length.
*/
if (unlikely(last_vcn >= 0 && rl[1].vcn > last_vcn)) {
s64 s1 = last_vcn + 1;
if (unlikely(rl[1].vcn > s1))
length = s1 - rl->vcn;
the_end = TRUE;
}
/* Write length. */
len_len = ntfs_write_significant_bytes(dst + 1, dst_max,
rl->length);
if (len_len < 0)
length);
if (unlikely(len_len < 0))
goto size_err;
/*
* If the logical cluster number (lcn) denotes a hole and we
......@@ -1316,17 +1383,17 @@ int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
* case on NT4. - We assume that we just need to write the lcn
* change until someone tells us otherwise... (AIA)
*/
if (rl->lcn >= 0 || vol->major_ver < 3) {
if (likely(rl->lcn >= 0 || vol->major_ver < 3)) {
/* Write change in lcn. */
lcn_len = ntfs_write_significant_bytes(dst + 1 +
len_len, dst_max, rl->lcn - prev_lcn);
if (lcn_len < 0)
if (unlikely(lcn_len < 0))
goto size_err;
prev_lcn = rl->lcn;
} else
lcn_len = 0;
dst_next = dst + len_len + lcn_len + 1;
if (dst_next > dst_max)
if (unlikely(dst_next > dst_max))
goto size_err;
/* Update header byte. */
*dst = lcn_len << 4 | len_len;
......
......@@ -84,11 +84,12 @@ extern runlist_element *ntfs_rl_find_vcn_nolock(runlist_element *rl,
const VCN vcn);
extern int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,
const runlist_element *rl, const VCN start_vcn);
const runlist_element *rl, const VCN first_vcn,
const VCN last_vcn);
extern int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
const int dst_len, const runlist_element *rl,
const VCN start_vcn, VCN *const stop_vcn);
const VCN first_vcn, const VCN last_vcn, VCN *const stop_vcn);
extern int ntfs_rl_truncate_nolock(const ntfs_volume *vol,
runlist *const runlist, const s64 new_length);
......
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