/* Temporary helper functions -- might become macros */
/**
- * rl_mm - run_list memmove
+ * ntfs_rl_mm - run_list memmove
*
* It is up to the caller to serialize access to the run list @base.
*/
-static inline void rl_mm(run_list_element *base, int dst, int src, int size)
+static inline void ntfs_rl_mm(run_list_element *base, int dst, int src,
+ int size)
{
- if ((dst != src) && (size > 0))
- memmove (base + dst, base + src, size * sizeof (*base));
+ if (likely((dst != src) && (size > 0)))
+ memmove(base + dst, base + src, size * sizeof (*base));
}
/**
- * rl_mc - run_list memory copy
+ * ntfs_rl_mc - run_list memory copy
*
* It is up to the caller to serialize access to the run lists @dstbase and
* @srcbase.
*/
-static inline void rl_mc(run_list_element *dstbase, int dst,
+static inline void ntfs_rl_mc(run_list_element *dstbase, int dst,
run_list_element *srcbase, int src, int size)
{
- if (size > 0)
- memcpy (dstbase+dst, srcbase+src, size * sizeof (*dstbase));
+ if (likely(size > 0))
+ memcpy(dstbase + dst, srcbase + src, size * sizeof(*dstbase));
}
/**
* ntfs_rl_realloc - Reallocate memory for run_lists
- * @orig: The original memory allocation
- * @old: The number of run_lists in the original
- * @new: The number of run_lists we need space for
+ * @rl: original run list
+ * @old_size: number of run list elements in the original run list @rl
+ * @new_size: number of run list elements we need space for
*
* As the run_lists grow, more memory will be required. To prevent the
* kernel having to allocate and reallocate large numbers of small bits of
* memory, this function returns and entire page of memory.
*
- * It is up to the caller to serialize access to the run list @orig.
+ * It is up to the caller to serialize access to the run list @rl.
*
* N.B. If the new allocation doesn't require a different number of pages in
* memory, the function will return the original pointer.
*
- * Return: Pointer The newly allocated, or recycled, memory.
- *
- * Errors: -ENOMEM, Not enough memory to allocate run list array.
- * -EINVAL, Invalid parameters were passed in.
+ * On success, return a pointer to the newly allocated, or recycled, memory.
+ * On error, return -errno. The following error codes are defined:
+ * -ENOMEM - Not enough memory to allocate run list array.
+ * -EINVAL - Invalid parameters were passed in.
*/
-static inline run_list_element *ntfs_rl_realloc(run_list_element *orig,
- int old, int new)
+static inline run_list_element *ntfs_rl_realloc(run_list_element *rl,
+ int old_size, int new_size)
{
- run_list_element *nrl;
+ run_list_element *new_rl;
- old = PAGE_ALIGN (old * sizeof (*orig));
- new = PAGE_ALIGN (new * sizeof (*orig));
- if (old == new)
- return orig;
+ old_size = PAGE_ALIGN(old_size * sizeof(*rl));
+ new_size = PAGE_ALIGN(new_size * sizeof(*rl));
+ if (old_size == new_size)
+ return rl;
- nrl = ntfs_malloc_nofs (new);
- if (!nrl)
- return ERR_PTR (-ENOMEM);
+ new_rl = ntfs_malloc_nofs(new_size);
+ if (unlikely(!new_rl))
+ return ERR_PTR(-ENOMEM);
- if (orig) {
- memcpy (nrl, orig, min (old, new));
- ntfs_free (orig);
+ if (likely(rl != NULL)) {
+ if (unlikely(old_size > new_size))
+ old_size = new_size;
+ memcpy(new_rl, rl, old_size);
+ ntfs_free(rl);
}
- return nrl;
+ return new_rl;
}
/**
- * ntfs_rl_merge - Join together two run_lists
- * @one: The first run_list and destination
- * @two: The second run_list
+ * ntfs_are_rl_mergeable - test if two run lists can be joined together
+ * @dst: original run list
+ * @src: new run list to test for mergeability with @dst
*
- * If possible merge together two run_lists. For this, their VCNs and LCNs
+ * Test if two run lists can be joined together. For this, their VCNs and LCNs
* must be adjacent.
*
- * It is up to the caller to serialize access to the run lists @one and @two.
+ * It is up to the caller to serialize access to the run lists @dst and @src.
*
- * Return: TRUE Success, the run_lists were merged
- * FALSE Failure, the run_lists were not merged
+ * Return: TRUE Success, the run lists can be merged.
+ * FALSE Failure, the run lists cannot be merged.
*/
-static inline BOOL ntfs_rl_merge(run_list_element *one, run_list_element *two)
+static inline BOOL ntfs_are_rl_mergeable(run_list_element *dst,
+ run_list_element *src)
{
- BUG_ON (!one || !two);
+ BUG_ON(!dst || !src);
- if ((one->lcn < 0) || (two->lcn < 0)) /* Are we merging holes? */
+ if ((dst->lcn < 0) || (src->lcn < 0)) /* Are we merging holes? */
return FALSE;
- if ((one->lcn + one->length) != two->lcn) /* Are the runs contiguous? */
+ if ((dst->lcn + dst->length) != src->lcn) /* Are the runs contiguous? */
return FALSE;
- if ((one->vcn + one->length) != two->vcn) /* Are the runs misaligned? */
+ if ((dst->vcn + dst->length) != src->vcn) /* Are the runs misaligned? */
return FALSE;
- one->length += two->length;
return TRUE;
}
/**
- * ntfs_rl_append - Append a run_list after the given element
- * @orig: The original run_list to be worked on.
- * @osize: The number of elements in @orig (including end marker).
- * @new: The run_list to be inserted.
- * @nsize: The number of elements in @new (excluding end marker).
- * @loc: Append the new run_list after this element in @orig.
+ * __ntfs_rl_merge - merge two run lists without testing if they can be merged
+ * @dst: original, destination run list
+ * @src: new run list to merge with @dst
*
- * Append a run_list after element @loc in @orig. Merge the right end of
- * the new run_list, if necessary. Adjust the size of the hole before the
- * appended run_list.
+ * Merge the two run lists, writing into the destination run list @dst. The
+ * caller must make sure the run lists can be merged or this will corrupt the
+ * destination run list.
*
- * It is up to the caller to serialize access to the run lists @orig and @new.
+ * It is up to the caller to serialize access to the run lists @dst and @src.
+ */
+static inline void __ntfs_rl_merge(run_list_element *dst, run_list_element *src)
+{
+ dst->length += src->length;
+}
+
+/**
+ * ntfs_rl_merge - test if two run lists can be joined together and merge them
+ * @dst: original, destination run list
+ * @src: new run list to merge with @dst
*
- * Return: Pointer, The new, combined, run_list
+ * Test if two run lists can be joined together. For this, their VCNs and LCNs
+ * must be adjacent. If they can be merged, perform the merge, writing into
+ * the destination run list @dst.
*
- * Errors: -ENOMEM, Not enough memory to allocate run list array.
- * -EINVAL, Invalid parameters were passed in.
+ * It is up to the caller to serialize access to the run lists @dst and @src.
+ *
+ * Return: TRUE Success, the run lists have been merged.
+ * FALSE Failure, the run lists cannot be merged and have not been
+ * modified.
*/
-static inline run_list_element *ntfs_rl_append(run_list_element *orig,
- int osize, run_list_element *new, int nsize, int loc)
+static inline BOOL ntfs_rl_merge(run_list_element *dst, run_list_element *src)
+{
+ BOOL merge = ntfs_are_rl_mergeable(dst, src);
+
+ if (merge)
+ __ntfs_rl_merge(dst, src);
+ return merge;
+}
+
+/**
+ * ntfs_rl_append - append a run list after a given element
+ * @dst: original run list to be worked on
+ * @dsize: number of elements in @dst (including end marker)
+ * @src: run list to be inserted into @dst
+ * @ssize: number of elements in @src (excluding end marker)
+ * @loc: append the new run list @src after this element in @dst
+ *
+ * Append the run list @src after element @loc in @dst. Merge the right end of
+ * the new run list, if necessary. Adjust the size of the hole before the
+ * appended run list.
+ *
+ * It is up to the caller to serialize access to the run lists @dst and @src.
+ *
+ * On success, return a pointer to the new, combined, run list. Note, both
+ * run lists @dst and @src are deallocated before returning so you cannot use
+ * the pointers for anything any more. (Strictly speaking the returned run list
+ * may be the same as @dst but this is irrelevant.)
+ *
+ * On error, return -errno. Both run lists are left unmodified. The following
+ * error codes are defined:
+ * -ENOMEM - Not enough memory to allocate run list array.
+ * -EINVAL - Invalid parameters were passed in.
+ */
+static inline run_list_element *ntfs_rl_append(run_list_element *dst,
+ int dsize, run_list_element *src, int ssize, int loc)
{
- run_list_element *res;
BOOL right;
+ int magic;
- BUG_ON (!orig || !new);
+ BUG_ON(!dst || !src);
+
+ /* First, check if the right hand end needs merging. */
+ right = ntfs_are_rl_mergeable(src + ssize - 1, dst + loc + 1);
+
+ /* Space required: @dst size + @src size, less one if we merged. */
+ dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - right);
+ if (IS_ERR(dst))
+ return dst;
+ /*
+ * We are guaranteed to succeed from here so can start modifying the
+ * original run lists.
+ */
/* First, merge the right hand end, if necessary. */
- right = ntfs_rl_merge (new + nsize - 1, orig + loc + 1);
+ if (right)
+ __ntfs_rl_merge(src + ssize - 1, dst + loc + 1);
- /* Space required: Orig size + New size, less one if we merged. */
- res = ntfs_rl_realloc (orig, osize, osize + nsize - right);
- if (IS_ERR (res))
- return res;
+ magic = loc + ssize;
- /* Move the tail of Orig out of the way, then copy in New. */
- rl_mm (res, loc + 1 + nsize, loc + 1 + right, osize - loc - 1 - right);
- rl_mc (res, loc + 1, new, 0, nsize);
+ /* Move the tail of @dst out of the way, then copy in @src. */
+ ntfs_rl_mm(dst, magic + 1, loc + 1 + right, dsize - loc - 1 - right);
+ ntfs_rl_mc(dst, loc + 1, src, 0, ssize);
/* Adjust the size of the preceding hole. */
- res[loc].length = res[loc+1].vcn - res[loc].vcn;
+ dst[loc].length = dst[loc + 1].vcn - dst[loc].vcn;
/* We may have changed the length of the file, so fix the end marker */
- if (res[loc+nsize+1].lcn == LCN_ENOENT)
- res[loc+nsize+1].vcn = res[loc+nsize].vcn + res[loc+nsize].length;
+ if (dst[magic + 1].lcn == LCN_ENOENT)
+ dst[magic + 1].vcn = dst[magic].vcn + dst[magic].length;
- return res;
+ return dst;
}
/**
- * ntfs_rl_insert - Insert a run_list into another
- * @orig: The original run_list to be worked on.
- * @osize: The number of elements in @orig (including end marker).
- * @new: The run_list to be inserted.
- * @nsize: The number of elements in @new (excluding end marker).
- * @loc: Insert the new run_list before this element in @orig.
- *
- * Insert a run_list before element @loc in @orig. Merge the left end of
- * the new run_list, if necessary. Adjust the size of the hole after the
- * inserted run_list.
- *
- * It is up to the caller to serialize access to the run lists @orig and @new.
- *
- * Return: Pointer, The new, combined, run_list
- *
- * Errors: -ENOMEM, Not enough memory to allocate run list array.
- * -EINVAL, Invalid parameters were passed in.
+ * ntfs_rl_insert - insert a run list into another
+ * @dst: original run list to be worked on
+ * @dsize: number of elements in @dst (including end marker)
+ * @src: new run list to be inserted
+ * @ssize: number of elements in @src (excluding end marker)
+ * @loc: insert the new run list @src before this element in @dst
+ *
+ * Insert the run list @src before element @loc in the run list @dst. Merge the
+ * left end of the new run list, if necessary. Adjust the size of the hole
+ * after the inserted run list.
+ *
+ * It is up to the caller to serialize access to the run lists @dst and @src.
+ *
+ * On success, return a pointer to the new, combined, run list. Note, both
+ * run lists @dst and @src are deallocated before returning so you cannot use
+ * the pointers for anything any more. (Strictly speaking the returned run list
+ * may be the same as @dst but this is irrelevant.)
+ *
+ * On error, return -errno. Both run lists are left unmodified. The following
+ * error codes are defined:
+ * -ENOMEM - Not enough memory to allocate run list array.
+ * -EINVAL - Invalid parameters were passed in.
*/
-static inline run_list_element *ntfs_rl_insert(run_list_element *orig,
- int osize, run_list_element *new, int nsize, int loc)
+static inline run_list_element *ntfs_rl_insert(run_list_element *dst,
+ int dsize, run_list_element *src, int ssize, int loc)
{
- run_list_element *res;
BOOL left = FALSE;
BOOL disc = FALSE; /* Discontinuity */
BOOL hole = FALSE; /* Following a hole */
+ int magic;
- BUG_ON (!orig || !new);
+ BUG_ON(!dst || !src);
- /* disc => Discontinuity between the end of Orig and the start of New.
+ /* disc => Discontinuity between the end of @dst and the start of @src.
* This means we might need to insert a hole.
- * hole => Orig ends with a hole or an unmapped region which we can
+ * hole => @dst ends with a hole or an unmapped region which we can
* extend to match the discontinuity. */
- if (loc == 0) {
- disc = (new[0].vcn > 0);
- } else {
- left = ntfs_rl_merge (orig + loc - 1, new);
+ if (loc == 0)
+ disc = (src[0].vcn > 0);
+ else {
+ s64 merged_length;
+
+ left = ntfs_are_rl_mergeable(dst + loc - 1, src);
+
+ merged_length = dst[loc - 1].length;
+ if (left)
+ merged_length += src->length;
- disc = (new[0].vcn > (orig[loc-1].vcn + orig[loc-1].length));
+ disc = (src[0].vcn > dst[loc - 1].vcn + merged_length);
if (disc)
- hole = (orig[loc-1].lcn == LCN_HOLE);
+ hole = (dst[loc - 1].lcn == LCN_HOLE);
}
- /* Space required: Orig size + New size, less one if we merged,
- * plus one if there was a discontinuity, less one for a trailing hole */
- res = ntfs_rl_realloc (orig, osize, osize + nsize - left + disc - hole);
- if (IS_ERR (res))
- return res;
+ /* Space required: @dst size + @src size, less one if we merged, plus
+ * one if there was a discontinuity, less one for a trailing hole. */
+ dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left + disc - hole);
+ if (IS_ERR(dst))
+ return dst;
+ /*
+ * We are guaranteed to succeed from here so can start modifying the
+ * original run list.
+ */
+
+ if (left)
+ __ntfs_rl_merge(dst + loc - 1, src);
- /* Move the tail of Orig out of the way, then copy in New. */
- rl_mm (res, loc + nsize - left + disc - hole, loc, osize - loc);
- rl_mc (res, loc + disc - hole, new, left, nsize - left);
+ magic = loc + ssize - left + disc - hole;
+
+ /* Move the tail of @dst out of the way, then copy in @src. */
+ ntfs_rl_mm(dst, magic, loc, dsize - loc);
+ ntfs_rl_mc(dst, loc + disc - hole, src, left, ssize - left);
/* Adjust the VCN of the last run ... */
- if (res[loc+nsize-left+disc-hole].lcn <= LCN_HOLE) {
- res[loc+nsize-left+disc-hole].vcn =
- res[loc+nsize-left+disc-hole-1].vcn +
- res[loc+nsize-left+disc-hole-1].length;
- }
+ if (dst[magic].lcn <= LCN_HOLE)
+ dst[magic].vcn = dst[magic - 1].vcn + dst[magic - 1].length;
/* ... and the length. */
- if ((res[loc+nsize-left+disc-hole].lcn == LCN_HOLE) ||
- (res[loc+nsize-left+disc-hole].lcn == LCN_RL_NOT_MAPPED)) {
- res[loc+nsize-left+disc-hole].length =
- res[loc+nsize-left+disc-hole+1].vcn -
- res[loc+nsize-left+disc-hole].vcn;
- }
+ if (dst[magic].lcn == LCN_HOLE || dst[magic].lcn == LCN_RL_NOT_MAPPED)
+ dst[magic].length = dst[magic + 1].vcn - dst[magic].vcn;
/* Writing beyond the end of the file and there's a discontinuity. */
if (disc) {
- if (hole) {
- res[loc-1].length = res[loc].vcn - res[loc-1].vcn;
- } else {
+ if (hole)
+ dst[loc - 1].length = dst[loc].vcn - dst[loc - 1].vcn;
+ else {
if (loc > 0) {
- res[loc].vcn = res[loc-1].vcn +
- res[loc-1].length;
- res[loc].length = res[loc+1].vcn - res[loc].vcn;
+ dst[loc].vcn = dst[loc - 1].vcn +
+ dst[loc - 1].length;
+ dst[loc].length = dst[loc + 1].vcn -
+ dst[loc].vcn;
} else {
- res[loc].vcn = 0;
- res[loc].length = res[loc+1].vcn;
+ dst[loc].vcn = 0;
+ dst[loc].length = dst[loc + 1].vcn;
}
- res[loc].lcn = LCN_RL_NOT_MAPPED;
+ dst[loc].lcn = LCN_RL_NOT_MAPPED;
}
- if (res[loc+nsize-left+disc].lcn == LCN_ENOENT)
- res[loc+nsize-left+disc].vcn = res[loc+nsize-left+disc-1].vcn +
- res[loc+nsize-left+disc-1].length;
- }
+ magic += hole;
- return res;
+ if (dst[magic].lcn == LCN_ENOENT)
+ dst[magic].vcn = dst[magic - 1].vcn +
+ dst[magic - 1].length;
+ }
+ return dst;
}
/**
- * ntfs_rl_replace - Overwrite a run_list element with another run_list
- * @orig: The original run_list to be worked on.
- * @osize: The number of elements in @orig (including end marker).
- * @new: The run_list to be inserted.
- * @nsize: The number of elements in @new (excluding end marker).
- * @loc: Index of run_list @orig to overwrite with @new.
- *
- * Replace the run_list at @loc with @new. Merge the left and right ends of
- * the inserted run_list, if necessary.
- *
- * It is up to the caller to serialize access to the run lists @orig and @new.
- *
- * Return: Pointer, The new, combined, run_list
- *
- * Errors: -ENOMEM, Not enough memory to allocate run list array.
- * -EINVAL, Invalid parameters were passed in.
+ * ntfs_rl_replace - overwrite a run_list element with another run list
+ * @dst: original run list to be worked on
+ * @dsize: number of elements in @dst (including end marker)
+ * @src: new run list to be inserted
+ * @ssize: number of elements in @src (excluding end marker)
+ * @loc: index in run list @dst to overwrite with @src
+ *
+ * Replace the run list element @dst at @loc with @src. Merge the left and
+ * right ends of the inserted run list, if necessary.
+ *
+ * It is up to the caller to serialize access to the run lists @dst and @src.
+ *
+ * On success, return a pointer to the new, combined, run list. Note, both
+ * run lists @dst and @src are deallocated before returning so you cannot use
+ * the pointers for anything any more. (Strictly speaking the returned run list
+ * may be the same as @dst but this is irrelevant.)
+ *
+ * On error, return -errno. Both run lists are left unmodified. The following
+ * error codes are defined:
+ * -ENOMEM - Not enough memory to allocate run list array.
+ * -EINVAL - Invalid parameters were passed in.
*/
-static inline run_list_element *ntfs_rl_replace(run_list_element *orig,
- int osize, run_list_element *new, int nsize, int loc)
+static inline run_list_element *ntfs_rl_replace(run_list_element *dst,
+ int dsize, run_list_element *src, int ssize, int loc)
{
- run_list_element *res;
BOOL left = FALSE;
BOOL right;
+ int magic;
- BUG_ON (!orig || !new);
+ BUG_ON(!dst || !src);
/* First, merge the left and right ends, if necessary. */
- right = ntfs_rl_merge (new + nsize - 1, orig + loc + 1);
+ right = ntfs_are_rl_mergeable(src + ssize - 1, dst + loc + 1);
if (loc > 0)
- left = ntfs_rl_merge (orig + loc - 1, new);
+ left = ntfs_are_rl_mergeable(dst + loc - 1, src);
+
+ /* Allocate some space. We'll need less if the left, right, or both
+ * ends were merged. */
+ dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left - right);
+ if (IS_ERR(dst))
+ return dst;
+ /*
+ * We are guaranteed to succeed from here so can start modifying the
+ * original run lists.
+ */
+ if (right)
+ __ntfs_rl_merge(src + ssize - 1, dst + loc + 1);
+ if (left)
+ __ntfs_rl_merge(dst + loc - 1, src);
- /* Allocate some space. We'll need less if the left, right
- * or both ends were merged. */
- res = ntfs_rl_realloc (orig, osize, osize + nsize - left - right);
- if (IS_ERR (res))
- return res;
+ /* FIXME: What does this mean? (AIA) */
+ magic = loc + ssize - left;
- /* Move the tail of Orig out of the way, then copy in New. */
- rl_mm (res, loc + nsize - left, loc + right + 1,
- osize - loc - right - 1);
- rl_mc (res, loc, new, left, nsize - left);
+ /* Move the tail of @dst out of the way, then copy in @src. */
+ ntfs_rl_mm(dst, magic, loc + right + 1, dsize - loc - right - 1);
+ ntfs_rl_mc(dst, loc, src, left, ssize - left);
/* We may have changed the length of the file, so fix the end marker */
- if (res[loc+nsize-left].lcn == LCN_ENOENT)
- res[loc+nsize-left].vcn = res[loc+nsize-left-1].vcn +
- res[loc+nsize-left-1].length;
- return res;
+ if (dst[magic].lcn == LCN_ENOENT)
+ dst[magic].vcn = dst[magic - 1].vcn + dst[magic - 1].length;
+ return dst;
}
/**
- * ntfs_rl_split - Insert a run_list into the centre of a hole
- * @orig: The original run_list to be worked on.
- * @osize: The number of elements in @orig (including end marker).
- * @new: The run_list to be inserted.
- * @nsize: The number of elements in @new (excluding end marker).
- * @loc: Index of run_list in @orig to split with @new.
- *
- * Split the run_list at @loc into two and insert @new. No merging of
- * run_lists is necessary. Adjust the size of the holes either side.
- *
- * It is up to the caller to serialize access to the run lists @orig and @new.
- *
- * Return: Pointer, The new, combined, run_list
- *
- * Errors: -ENOMEM, Not enough memory to allocate run list array.
- * -EINVAL, Invalid parameters were passed in.
+ * ntfs_rl_split - insert a run list into the centre of a hole
+ * @dst: original run list to be worked on
+ * @dsize: number of elements in @dst (including end marker)
+ * @src: new run list to be inserted
+ * @ssize: number of elements in @src (excluding end marker)
+ * @loc: index in run list @dst at which to split and insert @src
+ *
+ * Split the run list @dst at @loc into two and insert @new in between the two
+ * fragments. No merging of run lists is necessary. Adjust the size of the
+ * holes either side.
+ *
+ * It is up to the caller to serialize access to the run lists @dst and @src.
+ *
+ * On success, return a pointer to the new, combined, run list. Note, both
+ * run lists @dst and @src are deallocated before returning so you cannot use
+ * the pointers for anything any more. (Strictly speaking the returned run list
+ * may be the same as @dst but this is irrelevant.)
+ *
+ * On error, return -errno. Both run lists are left unmodified. The following
+ * error codes are defined:
+ * -ENOMEM - Not enough memory to allocate run list array.
+ * -EINVAL - Invalid parameters were passed in.
*/
-static inline run_list_element *ntfs_rl_split(run_list_element *orig, int osize,
- run_list_element *new, int nsize, int loc)
+static inline run_list_element *ntfs_rl_split(run_list_element *dst, int dsize,
+ run_list_element *src, int ssize, int loc)
{
- run_list_element *res;
-
- BUG_ON (!orig || !new);
+ BUG_ON(!dst || !src);
- /* Space required: Orig size + New size + One new hole. */
- res = ntfs_rl_realloc (orig, osize, osize + nsize + 1);
- if (IS_ERR (res))
- return res;
+ /* Space required: @dst size + @src size + one new hole. */
+ dst = ntfs_rl_realloc(dst, dsize, dsize + ssize + 1);
+ if (IS_ERR(dst))
+ return dst;
+ /*
+ * We are guaranteed to succeed from here so can start modifying the
+ * original run lists.
+ */
- /* Move the tail of Orig out of the way, then copy in New. */
- rl_mm (res, loc + 1 + nsize, loc, osize - loc);
- rl_mc (res, loc + 1, new, 0, nsize);
+ /* Move the tail of @dst out of the way, then copy in @src. */
+ ntfs_rl_mm(dst, loc + 1 + ssize, loc, dsize - loc);
+ ntfs_rl_mc(dst, loc + 1, src, 0, ssize);
- /* Adjust the size of the holes either size of New. */
- res[loc].length = res[loc+1].vcn - res[loc].vcn;
- res[loc+nsize+1].vcn = res[loc+nsize].vcn + res[loc+nsize].length;
- res[loc+nsize+1].length = res[loc+nsize+2].vcn - res[loc+nsize+1].vcn;
+ /* Adjust the size of the holes either size of @src. */
+ dst[loc].length = dst[loc+1].vcn - dst[loc].vcn;
+ dst[loc+ssize+1].vcn = dst[loc+ssize].vcn + dst[loc+ssize].length;
+ dst[loc+ssize+1].length = dst[loc+ssize+2].vcn - dst[loc+ssize+1].vcn;
- return res;
+ return dst;
}
/**
- * merge_run_lists - merge two run_lists into one
- * @drl: The original run_list.
- * @srl: The new run_list to be merge into @drl.
+ * ntfs_merge_run_lists - merge two run_lists into one
+ * @drl: original run list to be worked on
+ * @srl: new run list to be merged into @drl
*
- * First we sanity check the two run_lists to make sure that they are sensible
- * and can be merged. The @srl run_list must be either after the @drl run_list
- * or completely within a hole in @drl.
+ * First we sanity check the two run lists @srl and @drl to make sure that they
+ * are sensible and can be merged. The run list @srl must be either after the
+ * run list @drl or completely within a hole (or unmapped region) in @drl.
*
* It is up to the caller to serialize access to the run lists @drl and @srl.
*
* 1. When attribute lists are used and a further extent is being mapped.
* 2. When new clusters are allocated to fill a hole or extend a file.
*
- * There are four possible ways @srl can be merged. It can be inserted at
- * the beginning of a hole; split the hole in two; appended at the end of
- * a hole; replace the whole hole. It can also be appended to the end of
- * the run_list, which is just a variant of the insert case.
- *
- * N.B. Either, or both, of the input pointers may be freed if the function
- * is successful. Only the returned pointer may be used.
- *
- * If the function fails, neither of the input run_lists may be safe.
- *
- * Return: Pointer, The resultant merged run_list.
- *
- * Errors: -ENOMEM, Not enough memory to allocate run list array.
- * -EINVAL, Invalid parameters were passed in.
- * -ERANGE, The run_lists overlap and cannot be merged.
+ * There are four possible ways @srl can be merged. It can:
+ * - be inserted at the beginning of a hole,
+ * - split the hole in two and be inserted between the two fragments,
+ * - be appended at the end of a hole, or it can
+ * - replace the whole hole.
+ * It can also be appended to the end of the run list, which is just a variant
+ * of the insert case.
+ *
+ * On success, return a pointer to the new, combined, run list. Note, both
+ * run lists @drl and @srl are deallocated before returning so you cannot use
+ * the pointers for anything any more. (Strictly speaking the returned run list
+ * may be the same as @dst but this is irrelevant.)
+ *
+ * On error, return -errno. Both run lists are left unmodified. The following
+ * error codes are defined:
+ * -ENOMEM - Not enough memory to allocate run list array.
+ * -EINVAL - Invalid parameters were passed in.
+ * -ERANGE - The run lists overlap and cannot be merged.
*/
-run_list_element *merge_run_lists(run_list_element *drl, run_list_element *srl)
+run_list_element *ntfs_merge_run_lists(run_list_element *drl,
+ run_list_element *srl)
{
- run_list_element *nrl; /* New run list. */
int di, si; /* Current index into @[ds]rl. */
int sstart; /* First index with lcn > LCN_RL_NOT_MAPPED. */
int dins; /* Index into @drl at which to insert @srl. */
int dfinal, sfinal; /* The last index into @[ds]rl with
lcn >= LCN_HOLE. */
int marker = 0;
+ VCN marker_vcn = 0;
-#if 1
- ntfs_debug ("dst:");
- ntfs_debug_dump_runlist (drl);
- ntfs_debug ("src:");
- ntfs_debug_dump_runlist (srl);
+#ifdef DEBUG
+ ntfs_debug("dst:");
+ ntfs_debug_dump_runlist(drl);
+ ntfs_debug("src:");
+ ntfs_debug_dump_runlist(srl);
#endif
/* Check for silly calling... */
- if (unlikely (!srl))
+ if (unlikely(!srl))
return drl;
- if (unlikely (IS_ERR (srl) || IS_ERR (drl)))
- return ERR_PTR (-EINVAL);
+ if (unlikely(IS_ERR(srl) || IS_ERR(drl)))
+ return ERR_PTR(-EINVAL);
/* Check for the case where the first mapping is being done now. */
- if (unlikely (!drl)) {
- nrl = srl;
-
+ if (unlikely(!drl)) {
+ drl = srl;
/* Complete the source run list if necessary. */
- if (unlikely (srl[0].vcn)) {
+ if (unlikely(drl[0].vcn)) {
/* Scan to the end of the source run list. */
- for (send = 0; likely (srl[send].length); send++)
+ for (dend = 0; likely(drl[dend].length); dend++)
;
- nrl = ntfs_rl_realloc (srl, send, send + 1);
- if (!nrl)
- return ERR_PTR (-ENOMEM);
-
- rl_mm (nrl, 1, 0, send);
- nrl[0].vcn = 0; /* Add start element. */
- nrl[0].lcn = LCN_RL_NOT_MAPPED;
- nrl[0].length = nrl[1].vcn;
+ drl = ntfs_rl_realloc(drl, dend, dend + 1);
+ if (IS_ERR(drl))
+ return drl;
+ /* Insert start element at the front of the run list. */
+ ntfs_rl_mm(drl, 1, 0, dend);
+ drl[0].vcn = 0;
+ drl[0].lcn = LCN_RL_NOT_MAPPED;
+ drl[0].length = drl[1].vcn;
}
goto finished;
}
si = di = 0;
- /* Skip the unmapped start element(s) in each run_list if present. */
+ /* Skip any unmapped start element(s) in the source run_list. */
while (srl[si].length && srl[si].lcn < (LCN)LCN_HOLE)
si++;
- /* Can't have an entirely unmapped srl run_list. */
- BUG_ON (!srl[si].length);
+ /* Can't have an entirely unmapped source run list. */
+ BUG_ON(!srl[si].length);
/* Record the starting points. */
sstart = si;
* appended to @drl.
*/
for (; drl[di].length; di++) {
- if ((drl[di].vcn + drl[di].length) > srl[sstart].vcn)
+ if (drl[di].vcn + drl[di].length > srl[sstart].vcn)
break;
}
dins = di;
/* Sanity check for illegal overlaps. */
- if ((drl[di].vcn == srl[si].vcn) &&
- (drl[di].lcn >= 0) &&
- (srl[si].lcn >= 0)) {
- ntfs_error (NULL, "Run lists overlap. Cannot merge! Returning "
- "ERANGE.");
- nrl = ERR_PTR (-ERANGE);
- goto exit;
+ if ((drl[di].vcn == srl[si].vcn) && (drl[di].lcn >= 0) &&
+ (srl[si].lcn >= 0)) {
+ ntfs_error(NULL, "Run lists overlap. Cannot merge!");
+ return ERR_PTR(-ERANGE);
}
/* Scan to the end of both run lists in order to know their sizes. */
for (dend = di; drl[dend].length; dend++)
;
- if (srl[send].lcn == LCN_ENOENT) {
- marker = send;
- }
+ if (srl[send].lcn == (LCN)LCN_ENOENT)
+ marker_vcn = srl[marker = send].vcn;
/* Scan to the last element with lcn >= LCN_HOLE. */
for (sfinal = send; sfinal >= 0 && srl[sfinal].lcn < LCN_HOLE; sfinal--)
{
BOOL start;
BOOL finish;
- int ds = dend + 1; /* Number of elements in drl & srl */
+ int ds = dend + 1; /* Number of elements in drl & srl */
int ss = sfinal - sstart + 1;
start = ((drl[dins].lcn < LCN_RL_NOT_MAPPED) || /* End of file */
(drl[dins].vcn == srl[sstart].vcn)); /* Start of hole */
finish = ((drl[dins].lcn >= LCN_RL_NOT_MAPPED) && /* End of file */
((drl[dins].vcn + drl[dins].length) <= /* End of hole */
- (srl[send-1].vcn + srl[send-1].length)));
+ (srl[send - 1].vcn + srl[send - 1].length)));
/* Or we'll lose an end marker */
if (start && finish && (drl[dins].length == 0))
ss++;
- if (marker && (drl[dins].vcn + drl[dins].length > srl[send-1].vcn))
+ if (marker && (drl[dins].vcn + drl[dins].length > srl[send - 1].vcn))
finish = FALSE;
-
#if 0
ntfs_debug("dfinal = %i, dend = %i", dfinal, dend);
ntfs_debug("sstart = %i, sfinal = %i, send = %i", sstart, sfinal, send);
ntfs_debug("start = %i, finish = %i", start, finish);
ntfs_debug("ds = %i, ss = %i, dins = %i", ds, ss, dins);
#endif
- if (start)
+ if (start) {
if (finish)
- nrl = ntfs_rl_replace (drl, ds, srl + sstart, ss, dins);
+ drl = ntfs_rl_replace(drl, ds, srl + sstart, ss, dins);
else
- nrl = ntfs_rl_insert (drl, ds, srl + sstart, ss, dins);
- else
+ drl = ntfs_rl_insert(drl, ds, srl + sstart, ss, dins);
+ } else {
if (finish)
- nrl = ntfs_rl_append (drl, ds, srl + sstart, ss, dins);
+ drl = ntfs_rl_append(drl, ds, srl + sstart, ss, dins);
else
- nrl = ntfs_rl_split (drl, ds, srl + sstart, ss, dins);
-
- if (marker && !IS_ERR(nrl)) {
- for (ds = 0; nrl[ds].length; ds++)
+ drl = ntfs_rl_split(drl, ds, srl + sstart, ss, dins);
+ }
+ if (IS_ERR(drl)) {
+ ntfs_error(NULL, "Merge failed.");
+ return drl;
+ }
+ ntfs_free(srl);
+ if (marker) {
+ ntfs_debug("Triggering marker code.");
+ for (ds = dend; drl[ds].length; ds++)
;
- nrl = ntfs_rl_insert(nrl, ds + 1, srl + marker, 1, ds);
+ /* We only need to care if @srl ended after @drl. */
+ if (drl[ds].vcn <= marker_vcn) {
+ int slots = 0;
+
+ if (drl[ds].vcn == marker_vcn) {
+ ntfs_debug("Old marker = 0x%Lx, replacing with "
+ "LCN_ENOENT.\n",
+ (unsigned long long)
+ drl[ds].lcn);
+ drl[ds].lcn = (LCN)LCN_ENOENT;
+ goto finished;
+ }
+ /*
+ * We need to create an unmapped run list element in
+ * @drl or extend an existing one before adding the
+ * ENOENT terminator.
+ */
+ if (drl[ds].lcn == (LCN)LCN_ENOENT) {
+ ds--;
+ slots = 1;
+ }
+ if (drl[ds].lcn != (LCN)LCN_RL_NOT_MAPPED) {
+ /* Add an unmapped run list element. */
+ if (!slots) {
+ /* FIXME/TODO: We need to have the
+ * extra memory already! (AIA) */
+ drl = ntfs_rl_realloc(drl, ds, ds + 2);
+ if (!drl)
+ goto critical_error;
+ slots = 2;
+ }
+ ds++;
+ /* Need to set vcn if it isn't set already. */
+ if (slots != 1)
+ drl[ds].vcn = drl[ds - 1].vcn +
+ drl[ds - 1].length;
+ drl[ds].lcn = (LCN)LCN_RL_NOT_MAPPED;
+ /* We now used up a slot. */
+ slots--;
+ }
+ drl[ds].length = marker_vcn - drl[ds].vcn;
+ /* Finally add the ENOENT terminator. */
+ ds++;
+ if (!slots) {
+ /* FIXME/TODO: We need to have the extra
+ * memory already! (AIA) */
+ drl = ntfs_rl_realloc(drl, ds, ds + 1);
+ if (!drl)
+ goto critical_error;
+ }
+ drl[ds].vcn = marker_vcn;
+ drl[ds].lcn = (LCN)LCN_ENOENT;
+ drl[ds].length = (s64)0;
+ }
}
}
- if (likely (!IS_ERR (nrl))) {
- /* The merge was completed successfully. */
finished:
- if (nrl != srl)
- ntfs_free (srl);
- /*ntfs_debug ("Done.");*/
- /*ntfs_debug ("Merged run list:");*/
-
-#if 1
- ntfs_debug ("res:");
- ntfs_debug_dump_runlist (nrl);
-#endif
- } else {
- ntfs_error (NULL, "Merge failed, returning error code %ld.",
- -PTR_ERR (nrl));
- }
-exit:
- return nrl;
+ /* The merge was completed successfully. */
+ ntfs_debug("Merged run list:");
+ ntfs_debug_dump_runlist(drl);
+ return drl;
+
+critical_error:
+ /* Critical error! We cannot afford to fail here. */
+ ntfs_error(NULL, "Critical error! Not enough memory.");
+ panic("NTFS: Cannot continue.");
}
/**
* decompress_mapping_pairs - convert mapping pairs array to run list
* @vol: ntfs volume on which the attribute resides
* @attr: attribute record whose mapping pairs array to decompress
- * @run_list: optional run list in which to insert @attr's run list
- *
- * Decompress the attribute @attr's mapping pairs array into a run_list and
- * return the run list or -errno on error. If @run_list is not NULL then
- * the mapping pairs array of @attr is decompressed and the run list inserted
- * into the appropriate place in @run_list. If this is the case and the
- * function returns success, the original pointer passed into @run_list is no
- * longer valid.
+ * @old_rl: optional run list in which to insert @attr's run list
*
* It is up to the caller to serialize access to the run list @old_rl.
*
- * Check the return value for error with IS_ERR(ret_val). If this is FALSE,
- * the function was successful, the return value is the new run list, and if
- * an existing run list pointer was passed in, this is no longer valid.
- * If IS_ERR(ret_val) returns true, there was an error, the return value is not
- * a run_list pointer and the existing run list pointer if one was passed in
- * has not been touched. In this case use PTR_ERR(ret_val) to obtain the error
- * code. Following error codes are defined:
- * -ENOMEM Not enough memory to allocate run list array.
- * -EIO Corrupt run list.
- * -EINVAL Invalid parameters were passed in.
- * -ERANGE The two run lists overlap.
+ * Decompress the attribute @attr's mapping pairs array into a run list. On
+ * success, return the decompressed run list.
+ *
+ * If @old_rl is not NULL, decompressed run list is inserted into the
+ * appropriate place in @old_rl and the resultant, combined run list is
+ * returned. The original @old_rl is deallocated.
+ *
+ * On error, return -errno. @old_rl is left unmodified in that case.
+ *
+ * The following error codes are defined:
+ * -ENOMEM - Not enough memory to allocate run list array.
+ * -EIO - Corrupt run list.
+ * -EINVAL - Invalid parameters were passed in.
+ * -ERANGE - The two run lists overlap.
*
* FIXME: For now we take the conceptionally simplest approach of creating the
* new run list disregarding the already existing one and then splicing the
- * two into one if that is possible (we check for overlap and discard the new
- * run list if overlap present and return error).
+ * two into one, if that is possible (we check for overlap and discard the new
+ * run list if overlap present before returning ERR_PTR(-ERANGE)).
*/
run_list_element *decompress_mapping_pairs(const ntfs_volume *vol,
const ATTR_RECORD *attr, run_list_element *old_rl)
VCN vcn; /* Current vcn. */
LCN lcn; /* Current lcn. */
s64 deltaxcn; /* Change in [vl]cn. */
- run_list_element *rl = NULL; /* The output run_list. */
- run_list_element *rl2; /* Temporary run_list. */
+ run_list_element *rl; /* The output run list. */
u8 *buf; /* Current position in mapping pairs array. */
u8 *attr_end; /* End of attribute. */
- int rlsize; /* Size of run_list buffer. */
- int rlpos; /* Current run_list position. */
+ int rlsize; /* Size of run list buffer. */
+ u16 rlpos; /* Current run list position in units of
+ run_list_elements. */
u8 b; /* Current byte offset in buf. */
#ifdef DEBUG
ntfs_error(vol->sb, "Corrupt attribute.");
return ERR_PTR(-EIO);
}
- /* Current position in run_list array. */
+ /* Current position in run list array. */
rlpos = 0;
- /* Allocate first page. */
- rl = ntfs_malloc_nofs(PAGE_SIZE);
+ /* Allocate first page and set current run list size to one page. */
+ rl = ntfs_malloc_nofs(rlsize = PAGE_SIZE);
if (unlikely(!rl))
return ERR_PTR(-ENOMEM);
- /* Current run_list buffer size in bytes. */
- rlsize = PAGE_SIZE;
/* Insert unmapped starting element if necessary. */
if (vcn) {
rl->vcn = (VCN)0;
* operates on whole pages only.
*/
if (((rlpos + 3) * sizeof(*old_rl)) > rlsize) {
+ run_list_element *rl2;
+
rl2 = ntfs_malloc_nofs(rlsize + (int)PAGE_SIZE);
if (unlikely(!rl2)) {
ntfs_free(rl);
return ERR_PTR(-ENOMEM);
}
- memmove(rl2, rl, rlsize);
+ memcpy(rl2, rl, rlsize);
ntfs_free(rl);
rl = rl2;
rlsize += PAGE_SIZE;
}
/* Enter the current vcn into the current run_list element. */
- (rl + rlpos)->vcn = vcn;
+ rl[rlpos].vcn = vcn;
/*
* Get the change in vcn, i.e. the run length in clusters.
* Doing it this way ensures that we signextend negative values.
goto err_out;
}
/*
- * Enter the current run length into the current run_list
+ * Enter the current run length into the current run list
* element.
*/
- (rl + rlpos)->length = deltaxcn;
+ rl[rlpos].length = deltaxcn;
/* Increment the current vcn by the current run length. */
vcn += deltaxcn;
/*
* to LCN_HOLE.
*/
if (!(*buf & 0xf0))
- (rl + rlpos)->lcn = (LCN)LCN_HOLE;
+ rl[rlpos].lcn = (LCN)LCN_HOLE;
else {
/* Get the lcn change which really can be negative. */
u8 b2 = *buf & 0xf;
goto err_out;
}
/* Enter the current lcn into the run_list element. */
- (rl + rlpos)->lcn = lcn;
+ rl[rlpos].lcn = lcn;
}
/* Get to the next run_list element. */
rlpos++;
"non-resident attribute.");
goto err_out;
}
- /* Setup not mapped run_list element if this is the base extent. */
+ /* Setup not mapped run list element if this is the base extent. */
if (!attr->_ANR(lowest_vcn)) {
VCN max_cluster;
* likely, there are more extents following this one.
*/
if (deltaxcn < --max_cluster) {
- //RAR ntfs_debug("More extents to follow; deltaxcn = 0x%Lx, "
- //RAR "max_cluster = 0x%Lx",
- //RAR (long long)deltaxcn,
- //RAR (long long)max_cluster);
- (rl + rlpos)->vcn = vcn;
- vcn += (rl + rlpos)->length = max_cluster - deltaxcn;
- (rl + rlpos)->lcn = (LCN)LCN_RL_NOT_MAPPED;
+ ntfs_debug("More extents to follow; deltaxcn = 0x%Lx, "
+ "max_cluster = 0x%Lx",
+ (long long)deltaxcn,
+ (long long)max_cluster);
+ rl[rlpos].vcn = vcn;
+ vcn += rl[rlpos].length = max_cluster - deltaxcn;
+ rl[rlpos].lcn = (LCN)LCN_RL_NOT_MAPPED;
rlpos++;
} else if (unlikely(deltaxcn > max_cluster)) {
ntfs_error(vol->sb, "Corrupt attribute. deltaxcn = "
(long long)max_cluster);
goto mpa_err;
}
- (rl + rlpos)->lcn = (LCN)LCN_ENOENT;
+ rl[rlpos].lcn = (LCN)LCN_ENOENT;
} else /* Not the base extent. There may be more extents to follow. */
- (rl + rlpos)->lcn = (LCN)LCN_RL_NOT_MAPPED;
+ rl[rlpos].lcn = (LCN)LCN_RL_NOT_MAPPED;
/* Setup terminating run_list element. */
- (rl + rlpos)->vcn = vcn;
- (rl + rlpos)->length = (s64)0;
- //RAR ntfs_debug("Mapping pairs array successfully decompressed.");
- //RAR ntfs_debug_dump_runlist(rl);
+ rl[rlpos].vcn = vcn;
+ rl[rlpos].length = (s64)0;
/* If no existing run list was specified, we are done. */
- if (!old_rl)
+ if (!old_rl) {
+ ntfs_debug("Mapping pairs array successfully decompressed:");
+ ntfs_debug_dump_runlist(rl);
return rl;
+ }
/* Now combine the new and old run lists checking for overlaps. */
- rl2 = merge_run_lists(old_rl, rl);
- if (likely(!IS_ERR(rl2)))
- return rl2;
+ old_rl = ntfs_merge_run_lists(old_rl, rl);
+ if (likely(!IS_ERR(old_rl)))
+ return old_rl;
ntfs_free(rl);
ntfs_error(vol->sb, "Failed to merge run lists.");
- return rl2;
+ return old_rl;
io_error:
ntfs_error(vol->sb, "Corrupt attribute.");
err_out:
projects / linux / commitdiff