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-rw-r--r--fs/ntfs/runlist.c1893
1 files changed, 0 insertions, 1893 deletions
diff --git a/fs/ntfs/runlist.c b/fs/ntfs/runlist.c
deleted file mode 100644
index 0d448e9881..0000000000
--- a/fs/ntfs/runlist.c
+++ /dev/null
@@ -1,1893 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * runlist.c - NTFS runlist handling code. Part of the Linux-NTFS project.
- *
- * Copyright (c) 2001-2007 Anton Altaparmakov
- * Copyright (c) 2002-2005 Richard Russon
- */
-
-#include "debug.h"
-#include "dir.h"
-#include "endian.h"
-#include "malloc.h"
-#include "ntfs.h"
-
-/**
- * ntfs_rl_mm - runlist memmove
- *
- * It is up to the caller to serialize access to the runlist @base.
- */
-static inline void ntfs_rl_mm(runlist_element *base, int dst, int src,
- int size)
-{
- if (likely((dst != src) && (size > 0)))
- memmove(base + dst, base + src, size * sizeof(*base));
-}
-
-/**
- * ntfs_rl_mc - runlist memory copy
- *
- * It is up to the caller to serialize access to the runlists @dstbase and
- * @srcbase.
- */
-static inline void ntfs_rl_mc(runlist_element *dstbase, int dst,
- runlist_element *srcbase, int src, int size)
-{
- if (likely(size > 0))
- memcpy(dstbase + dst, srcbase + src, size * sizeof(*dstbase));
-}
-
-/**
- * ntfs_rl_realloc - Reallocate memory for runlists
- * @rl: original runlist
- * @old_size: number of runlist elements in the original runlist @rl
- * @new_size: number of runlist elements we need space for
- *
- * As the runlists 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 an entire page of memory.
- *
- * It is up to the caller to serialize access to the runlist @rl.
- *
- * N.B. If the new allocation doesn't require a different number of pages in
- * memory, the function will return the original pointer.
- *
- * 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 runlist array.
- * -EINVAL - Invalid parameters were passed in.
- */
-static inline runlist_element *ntfs_rl_realloc(runlist_element *rl,
- int old_size, int new_size)
-{
- runlist_element *new_rl;
-
- old_size = PAGE_ALIGN(old_size * sizeof(*rl));
- new_size = PAGE_ALIGN(new_size * sizeof(*rl));
- if (old_size == new_size)
- return rl;
-
- new_rl = ntfs_malloc_nofs(new_size);
- if (unlikely(!new_rl))
- return ERR_PTR(-ENOMEM);
-
- if (likely(rl != NULL)) {
- if (unlikely(old_size > new_size))
- old_size = new_size;
- memcpy(new_rl, rl, old_size);
- ntfs_free(rl);
- }
- return new_rl;
-}
-
-/**
- * ntfs_rl_realloc_nofail - Reallocate memory for runlists
- * @rl: original runlist
- * @old_size: number of runlist elements in the original runlist @rl
- * @new_size: number of runlist elements we need space for
- *
- * As the runlists 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 an entire page of memory.
- *
- * This function guarantees that the allocation will succeed. It will sleep
- * for as long as it takes to complete the allocation.
- *
- * It is up to the caller to serialize access to the runlist @rl.
- *
- * N.B. If the new allocation doesn't require a different number of pages in
- * memory, the function will return the original pointer.
- *
- * 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 runlist array.
- * -EINVAL - Invalid parameters were passed in.
- */
-static inline runlist_element *ntfs_rl_realloc_nofail(runlist_element *rl,
- int old_size, int new_size)
-{
- runlist_element *new_rl;
-
- old_size = PAGE_ALIGN(old_size * sizeof(*rl));
- new_size = PAGE_ALIGN(new_size * sizeof(*rl));
- if (old_size == new_size)
- return rl;
-
- new_rl = ntfs_malloc_nofs_nofail(new_size);
- BUG_ON(!new_rl);
-
- if (likely(rl != NULL)) {
- if (unlikely(old_size > new_size))
- old_size = new_size;
- memcpy(new_rl, rl, old_size);
- ntfs_free(rl);
- }
- return new_rl;
-}
-
-/**
- * ntfs_are_rl_mergeable - test if two runlists can be joined together
- * @dst: original runlist
- * @src: new runlist to test for mergeability with @dst
- *
- * Test if two runlists can be joined together. For this, their VCNs and LCNs
- * must be adjacent.
- *
- * It is up to the caller to serialize access to the runlists @dst and @src.
- *
- * Return: true Success, the runlists can be merged.
- * false Failure, the runlists cannot be merged.
- */
-static inline bool ntfs_are_rl_mergeable(runlist_element *dst,
- runlist_element *src)
-{
- BUG_ON(!dst);
- BUG_ON(!src);
-
- /* We can merge unmapped regions even if they are misaligned. */
- if ((dst->lcn == LCN_RL_NOT_MAPPED) && (src->lcn == LCN_RL_NOT_MAPPED))
- return true;
- /* If the runs are misaligned, we cannot merge them. */
- if ((dst->vcn + dst->length) != src->vcn)
- return false;
- /* If both runs are non-sparse and contiguous, we can merge them. */
- if ((dst->lcn >= 0) && (src->lcn >= 0) &&
- ((dst->lcn + dst->length) == src->lcn))
- return true;
- /* If we are merging two holes, we can merge them. */
- if ((dst->lcn == LCN_HOLE) && (src->lcn == LCN_HOLE))
- return true;
- /* Cannot merge. */
- return false;
-}
-
-/**
- * __ntfs_rl_merge - merge two runlists without testing if they can be merged
- * @dst: original, destination runlist
- * @src: new runlist to merge with @dst
- *
- * Merge the two runlists, writing into the destination runlist @dst. The
- * caller must make sure the runlists can be merged or this will corrupt the
- * destination runlist.
- *
- * It is up to the caller to serialize access to the runlists @dst and @src.
- */
-static inline void __ntfs_rl_merge(runlist_element *dst, runlist_element *src)
-{
- dst->length += src->length;
-}
-
-/**
- * ntfs_rl_append - append a runlist after a given element
- * @dst: original runlist to be worked on
- * @dsize: number of elements in @dst (including end marker)
- * @src: runlist to be inserted into @dst
- * @ssize: number of elements in @src (excluding end marker)
- * @loc: append the new runlist @src after this element in @dst
- *
- * Append the runlist @src after element @loc in @dst. Merge the right end of
- * the new runlist, if necessary. Adjust the size of the hole before the
- * appended runlist.
- *
- * It is up to the caller to serialize access to the runlists @dst and @src.
- *
- * On success, return a pointer to the new, combined, runlist. Note, both
- * runlists @dst and @src are deallocated before returning so you cannot use
- * the pointers for anything any more. (Strictly speaking the returned runlist
- * may be the same as @dst but this is irrelevant.)
- *
- * On error, return -errno. Both runlists are left unmodified. The following
- * error codes are defined:
- * -ENOMEM - Not enough memory to allocate runlist array.
- * -EINVAL - Invalid parameters were passed in.
- */
-static inline runlist_element *ntfs_rl_append(runlist_element *dst,
- int dsize, runlist_element *src, int ssize, int loc)
-{
- bool right = false; /* Right end of @src needs merging. */
- int marker; /* End of the inserted runs. */
-
- BUG_ON(!dst);
- BUG_ON(!src);
-
- /* First, check if the right hand end needs merging. */
- if ((loc + 1) < dsize)
- 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 runlists.
- */
-
- /* First, merge the right hand end, if necessary. */
- if (right)
- __ntfs_rl_merge(src + ssize - 1, dst + loc + 1);
-
- /* First run after the @src runs that have been inserted. */
- marker = loc + ssize + 1;
-
- /* Move the tail of @dst out of the way, then copy in @src. */
- ntfs_rl_mm(dst, marker, loc + 1 + right, dsize - (loc + 1 + right));
- ntfs_rl_mc(dst, loc + 1, src, 0, ssize);
-
- /* Adjust the size of the preceding hole. */
- 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 (dst[marker].lcn == LCN_ENOENT)
- dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length;
-
- return dst;
-}
-
-/**
- * ntfs_rl_insert - insert a runlist into another
- * @dst: original runlist to be worked on
- * @dsize: number of elements in @dst (including end marker)
- * @src: new runlist to be inserted
- * @ssize: number of elements in @src (excluding end marker)
- * @loc: insert the new runlist @src before this element in @dst
- *
- * Insert the runlist @src before element @loc in the runlist @dst. Merge the
- * left end of the new runlist, if necessary. Adjust the size of the hole
- * after the inserted runlist.
- *
- * It is up to the caller to serialize access to the runlists @dst and @src.
- *
- * On success, return a pointer to the new, combined, runlist. Note, both
- * runlists @dst and @src are deallocated before returning so you cannot use
- * the pointers for anything any more. (Strictly speaking the returned runlist
- * may be the same as @dst but this is irrelevant.)
- *
- * On error, return -errno. Both runlists are left unmodified. The following
- * error codes are defined:
- * -ENOMEM - Not enough memory to allocate runlist array.
- * -EINVAL - Invalid parameters were passed in.
- */
-static inline runlist_element *ntfs_rl_insert(runlist_element *dst,
- int dsize, runlist_element *src, int ssize, int loc)
-{
- bool left = false; /* Left end of @src needs merging. */
- bool disc = false; /* Discontinuity between @dst and @src. */
- int marker; /* End of the inserted runs. */
-
- BUG_ON(!dst);
- BUG_ON(!src);
-
- /*
- * disc => Discontinuity between the end of @dst and the start of @src.
- * This means we might need to insert a "not mapped" run.
- */
- 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 = (src[0].vcn > dst[loc - 1].vcn + merged_length);
- }
- /*
- * Space required: @dst size + @src size, less one if we merged, plus
- * one if there was a discontinuity.
- */
- dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left + disc);
- if (IS_ERR(dst))
- return dst;
- /*
- * We are guaranteed to succeed from here so can start modifying the
- * original runlist.
- */
- if (left)
- __ntfs_rl_merge(dst + loc - 1, src);
- /*
- * First run after the @src runs that have been inserted.
- * Nominally, @marker equals @loc + @ssize, i.e. location + number of
- * runs in @src. However, if @left, then the first run in @src has
- * been merged with one in @dst. And if @disc, then @dst and @src do
- * not meet and we need an extra run to fill the gap.
- */
- marker = loc + ssize - left + disc;
-
- /* Move the tail of @dst out of the way, then copy in @src. */
- ntfs_rl_mm(dst, marker, loc, dsize - loc);
- ntfs_rl_mc(dst, loc + disc, src, left, ssize - left);
-
- /* Adjust the VCN of the first run after the insertion... */
- dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length;
- /* ... and the length. */
- if (dst[marker].lcn == LCN_HOLE || dst[marker].lcn == LCN_RL_NOT_MAPPED)
- dst[marker].length = dst[marker + 1].vcn - dst[marker].vcn;
-
- /* Writing beyond the end of the file and there is a discontinuity. */
- if (disc) {
- if (loc > 0) {
- dst[loc].vcn = dst[loc - 1].vcn + dst[loc - 1].length;
- dst[loc].length = dst[loc + 1].vcn - dst[loc].vcn;
- } else {
- dst[loc].vcn = 0;
- dst[loc].length = dst[loc + 1].vcn;
- }
- dst[loc].lcn = LCN_RL_NOT_MAPPED;
- }
- return dst;
-}
-
-/**
- * ntfs_rl_replace - overwrite a runlist element with another runlist
- * @dst: original runlist to be worked on
- * @dsize: number of elements in @dst (including end marker)
- * @src: new runlist to be inserted
- * @ssize: number of elements in @src (excluding end marker)
- * @loc: index in runlist @dst to overwrite with @src
- *
- * Replace the runlist element @dst at @loc with @src. Merge the left and
- * right ends of the inserted runlist, if necessary.
- *
- * It is up to the caller to serialize access to the runlists @dst and @src.
- *
- * On success, return a pointer to the new, combined, runlist. Note, both
- * runlists @dst and @src are deallocated before returning so you cannot use
- * the pointers for anything any more. (Strictly speaking the returned runlist
- * may be the same as @dst but this is irrelevant.)
- *
- * On error, return -errno. Both runlists are left unmodified. The following
- * error codes are defined:
- * -ENOMEM - Not enough memory to allocate runlist array.
- * -EINVAL - Invalid parameters were passed in.
- */
-static inline runlist_element *ntfs_rl_replace(runlist_element *dst,
- int dsize, runlist_element *src, int ssize, int loc)
-{
- signed delta;
- bool left = false; /* Left end of @src needs merging. */
- bool right = false; /* Right end of @src needs merging. */
- int tail; /* Start of tail of @dst. */
- int marker; /* End of the inserted runs. */
-
- BUG_ON(!dst);
- BUG_ON(!src);
-
- /* First, see if the left and right ends need merging. */
- if ((loc + 1) < dsize)
- right = ntfs_are_rl_mergeable(src + ssize - 1, dst + loc + 1);
- if (loc > 0)
- left = ntfs_are_rl_mergeable(dst + loc - 1, src);
- /*
- * Allocate some space. We will need less if the left, right, or both
- * ends get merged. The -1 accounts for the run being replaced.
- */
- delta = ssize - 1 - left - right;
- if (delta > 0) {
- dst = ntfs_rl_realloc(dst, dsize, dsize + delta);
- if (IS_ERR(dst))
- return dst;
- }
- /*
- * We are guaranteed to succeed from here so can start modifying the
- * original runlists.
- */
-
- /* First, merge the left and right ends, if necessary. */
- if (right)
- __ntfs_rl_merge(src + ssize - 1, dst + loc + 1);
- if (left)
- __ntfs_rl_merge(dst + loc - 1, src);
- /*
- * Offset of the tail of @dst. This needs to be moved out of the way
- * to make space for the runs to be copied from @src, i.e. the first
- * run of the tail of @dst.
- * Nominally, @tail equals @loc + 1, i.e. location, skipping the
- * replaced run. However, if @right, then one of @dst's runs is
- * already merged into @src.
- */
- tail = loc + right + 1;
- /*
- * First run after the @src runs that have been inserted, i.e. where
- * the tail of @dst needs to be moved to.
- * Nominally, @marker equals @loc + @ssize, i.e. location + number of
- * runs in @src. However, if @left, then the first run in @src has
- * been merged with one in @dst.
- */
- marker = loc + ssize - left;
-
- /* Move the tail of @dst out of the way, then copy in @src. */
- ntfs_rl_mm(dst, marker, tail, dsize - tail);
- ntfs_rl_mc(dst, loc, src, left, ssize - left);
-
- /* We may have changed the length of the file, so fix the end marker. */
- if (dsize - tail > 0 && dst[marker].lcn == LCN_ENOENT)
- dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length;
- return dst;
-}
-
-/**
- * ntfs_rl_split - insert a runlist into the centre of a hole
- * @dst: original runlist to be worked on
- * @dsize: number of elements in @dst (including end marker)
- * @src: new runlist to be inserted
- * @ssize: number of elements in @src (excluding end marker)
- * @loc: index in runlist @dst at which to split and insert @src
- *
- * Split the runlist @dst at @loc into two and insert @new in between the two
- * fragments. No merging of runlists is necessary. Adjust the size of the
- * holes either side.
- *
- * It is up to the caller to serialize access to the runlists @dst and @src.
- *
- * On success, return a pointer to the new, combined, runlist. Note, both
- * runlists @dst and @src are deallocated before returning so you cannot use
- * the pointers for anything any more. (Strictly speaking the returned runlist
- * may be the same as @dst but this is irrelevant.)
- *
- * On error, return -errno. Both runlists are left unmodified. The following
- * error codes are defined:
- * -ENOMEM - Not enough memory to allocate runlist array.
- * -EINVAL - Invalid parameters were passed in.
- */
-static inline runlist_element *ntfs_rl_split(runlist_element *dst, int dsize,
- runlist_element *src, int ssize, int loc)
-{
- BUG_ON(!dst);
- BUG_ON(!src);
-
- /* 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 runlists.
- */
-
- /* 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 @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 dst;
-}
-
-/**
- * ntfs_runlists_merge - merge two runlists into one
- * @drl: original runlist to be worked on
- * @srl: new runlist to be merged into @drl
- *
- * First we sanity check the two runlists @srl and @drl to make sure that they
- * are sensible and can be merged. The runlist @srl must be either after the
- * runlist @drl or completely within a hole (or unmapped region) in @drl.
- *
- * It is up to the caller to serialize access to the runlists @drl and @srl.
- *
- * Merging of runlists is necessary in two cases:
- * 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 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 runlist, which is just a variant
- * of the insert case.
- *
- * On success, return a pointer to the new, combined, runlist. Note, both
- * runlists @drl and @srl are deallocated before returning so you cannot use
- * the pointers for anything any more. (Strictly speaking the returned runlist
- * may be the same as @dst but this is irrelevant.)
- *
- * On error, return -errno. Both runlists are left unmodified. The following
- * error codes are defined:
- * -ENOMEM - Not enough memory to allocate runlist array.
- * -EINVAL - Invalid parameters were passed in.
- * -ERANGE - The runlists overlap and cannot be merged.
- */
-runlist_element *ntfs_runlists_merge(runlist_element *drl,
- runlist_element *srl)
-{
- 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 dend, send; /* Last index into @[ds]rl. */
- int dfinal, sfinal; /* The last index into @[ds]rl with
- lcn >= LCN_HOLE. */
- int marker = 0;
- VCN marker_vcn = 0;
-
-#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))
- return drl;
- if (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)) {
- drl = srl;
- /* Complete the source runlist if necessary. */
- if (unlikely(drl[0].vcn)) {
- /* Scan to the end of the source runlist. */
- for (dend = 0; likely(drl[dend].length); dend++)
- ;
- dend++;
- drl = ntfs_rl_realloc(drl, dend, dend + 1);
- if (IS_ERR(drl))
- return drl;
- /* Insert start element at the front of the runlist. */
- 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 any unmapped start element(s) in the source runlist. */
- while (srl[si].length && srl[si].lcn < LCN_HOLE)
- si++;
-
- /* Can't have an entirely unmapped source runlist. */
- BUG_ON(!srl[si].length);
-
- /* Record the starting points. */
- sstart = si;
-
- /*
- * Skip forward in @drl until we reach the position where @srl needs to
- * be inserted. If we reach the end of @drl, @srl just needs to be
- * appended to @drl.
- */
- for (; drl[di].length; di++) {
- 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!");
- return ERR_PTR(-ERANGE);
- }
-
- /* Scan to the end of both runlists in order to know their sizes. */
- for (send = si; srl[send].length; send++)
- ;
- for (dend = di; drl[dend].length; dend++)
- ;
-
- if (srl[send].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--)
- ;
- for (dfinal = dend; dfinal >= 0 && drl[dfinal].lcn < LCN_HOLE; dfinal--)
- ;
-
- {
- bool start;
- bool finish;
- 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)));
-
- /* Or we will lose an end marker. */
- if (finish && !drl[dins].length)
- ss++;
- 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 (finish)
- drl = ntfs_rl_replace(drl, ds, srl + sstart, ss, dins);
- else
- drl = ntfs_rl_insert(drl, ds, srl + sstart, ss, dins);
- } else {
- if (finish)
- drl = ntfs_rl_append(drl, ds, srl + sstart, ss, dins);
- else
- 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++)
- ;
- /* 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%llx, replacing "
- "with LCN_ENOENT.",
- (unsigned long long)
- drl[ds].lcn);
- drl[ds].lcn = LCN_ENOENT;
- goto finished;
- }
- /*
- * We need to create an unmapped runlist element in
- * @drl or extend an existing one before adding the
- * ENOENT terminator.
- */
- if (drl[ds].lcn == LCN_ENOENT) {
- ds--;
- slots = 1;
- }
- if (drl[ds].lcn != LCN_RL_NOT_MAPPED) {
- /* Add an unmapped runlist element. */
- if (!slots) {
- drl = ntfs_rl_realloc_nofail(drl, ds,
- ds + 2);
- 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_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)
- drl = ntfs_rl_realloc_nofail(drl, ds, ds + 1);
- drl[ds].vcn = marker_vcn;
- drl[ds].lcn = LCN_ENOENT;
- drl[ds].length = (s64)0;
- }
- }
- }
-
-finished:
- /* The merge was completed successfully. */
- ntfs_debug("Merged runlist:");
- ntfs_debug_dump_runlist(drl);
- return drl;
-}
-
-/**
- * ntfs_mapping_pairs_decompress - convert mapping pairs array to runlist
- * @vol: ntfs volume on which the attribute resides
- * @attr: attribute record whose mapping pairs array to decompress
- * @old_rl: optional runlist in which to insert @attr's runlist
- *
- * It is up to the caller to serialize access to the runlist @old_rl.
- *
- * Decompress the attribute @attr's mapping pairs array into a runlist. On
- * success, return the decompressed runlist.
- *
- * If @old_rl is not NULL, decompressed runlist is inserted into the
- * appropriate place in @old_rl and the resultant, combined runlist 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 runlist array.
- * -EIO - Corrupt runlist.
- * -EINVAL - Invalid parameters were passed in.
- * -ERANGE - The two runlists overlap.
- *
- * FIXME: For now we take the conceptionally simplest approach of creating the
- * new runlist disregarding the already existing one and then splicing the
- * two into one, if that is possible (we check for overlap and discard the new
- * runlist if overlap present before returning ERR_PTR(-ERANGE)).
- */
-runlist_element *ntfs_mapping_pairs_decompress(const ntfs_volume *vol,
- const ATTR_RECORD *attr, runlist_element *old_rl)
-{
- VCN vcn; /* Current vcn. */
- LCN lcn; /* Current lcn. */
- s64 deltaxcn; /* Change in [vl]cn. */
- runlist_element *rl; /* The output runlist. */
- u8 *buf; /* Current position in mapping pairs array. */
- u8 *attr_end; /* End of attribute. */
- int rlsize; /* Size of runlist buffer. */
- u16 rlpos; /* Current runlist position in units of
- runlist_elements. */
- u8 b; /* Current byte offset in buf. */
-
-#ifdef DEBUG
- /* Make sure attr exists and is non-resident. */
- if (!attr || !attr->non_resident || sle64_to_cpu(
- attr->data.non_resident.lowest_vcn) < (VCN)0) {
- ntfs_error(vol->sb, "Invalid arguments.");
- return ERR_PTR(-EINVAL);
- }
-#endif
- /* Start at vcn = lowest_vcn and lcn 0. */
- vcn = sle64_to_cpu(attr->data.non_resident.lowest_vcn);
- lcn = 0;
- /* Get start of the mapping pairs array. */
- buf = (u8*)attr + le16_to_cpu(
- attr->data.non_resident.mapping_pairs_offset);
- attr_end = (u8*)attr + le32_to_cpu(attr->length);
- if (unlikely(buf < (u8*)attr || buf > attr_end)) {
- ntfs_error(vol->sb, "Corrupt attribute.");
- return ERR_PTR(-EIO);
- }
- /* If the mapping pairs array is valid but empty, nothing to do. */
- if (!vcn && !*buf)
- return old_rl;
- /* Current position in runlist array. */
- rlpos = 0;
- /* Allocate first page and set current runlist size to one page. */
- rl = ntfs_malloc_nofs(rlsize = PAGE_SIZE);
- if (unlikely(!rl))
- return ERR_PTR(-ENOMEM);
- /* Insert unmapped starting element if necessary. */
- if (vcn) {
- rl->vcn = 0;
- rl->lcn = LCN_RL_NOT_MAPPED;
- rl->length = vcn;
- rlpos++;
- }
- while (buf < attr_end && *buf) {
- /*
- * Allocate more memory if needed, including space for the
- * not-mapped and terminator elements. ntfs_malloc_nofs()
- * operates on whole pages only.
- */
- if (((rlpos + 3) * sizeof(*old_rl)) > rlsize) {
- runlist_element *rl2;
-
- rl2 = ntfs_malloc_nofs(rlsize + (int)PAGE_SIZE);
- if (unlikely(!rl2)) {
- ntfs_free(rl);
- return ERR_PTR(-ENOMEM);
- }
- memcpy(rl2, rl, rlsize);
- ntfs_free(rl);
- rl = rl2;
- rlsize += PAGE_SIZE;
- }
- /* Enter the current vcn into the current runlist element. */
- 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.
- * A negative run length doesn't make any sense, but hey, I
- * didn't make up the NTFS specs and Windows NT4 treats the run
- * length as a signed value so that's how it is...
- */
- b = *buf & 0xf;
- if (b) {
- if (unlikely(buf + b > attr_end))
- goto io_error;
- for (deltaxcn = (s8)buf[b--]; b; b--)
- deltaxcn = (deltaxcn << 8) + buf[b];
- } else { /* The length entry is compulsory. */
- ntfs_error(vol->sb, "Missing length entry in mapping "
- "pairs array.");
- deltaxcn = (s64)-1;
- }
- /*
- * Assume a negative length to indicate data corruption and
- * hence clean-up and return NULL.
- */
- if (unlikely(deltaxcn < 0)) {
- ntfs_error(vol->sb, "Invalid length in mapping pairs "
- "array.");
- goto err_out;
- }
- /*
- * Enter the current run length into the current runlist
- * element.
- */
- rl[rlpos].length = deltaxcn;
- /* Increment the current vcn by the current run length. */
- vcn += deltaxcn;
- /*
- * There might be no lcn change at all, as is the case for
- * sparse clusters on NTFS 3.0+, in which case we set the lcn
- * to LCN_HOLE.
- */
- if (!(*buf & 0xf0))
- rl[rlpos].lcn = LCN_HOLE;
- else {
- /* Get the lcn change which really can be negative. */
- u8 b2 = *buf & 0xf;
- b = b2 + ((*buf >> 4) & 0xf);
- if (buf + b > attr_end)
- goto io_error;
- for (deltaxcn = (s8)buf[b--]; b > b2; b--)
- deltaxcn = (deltaxcn << 8) + buf[b];
- /* Change the current lcn to its new value. */
- lcn += deltaxcn;
-#ifdef DEBUG
- /*
- * On NTFS 1.2-, apparently can have lcn == -1 to
- * indicate a hole. But we haven't verified ourselves
- * whether it is really the lcn or the deltaxcn that is
- * -1. So if either is found give us a message so we
- * can investigate it further!
- */
- if (vol->major_ver < 3) {
- if (unlikely(deltaxcn == (LCN)-1))
- ntfs_error(vol->sb, "lcn delta == -1");
- if (unlikely(lcn == (LCN)-1))
- ntfs_error(vol->sb, "lcn == -1");
- }
-#endif
- /* Check lcn is not below -1. */
- if (unlikely(lcn < (LCN)-1)) {
- ntfs_error(vol->sb, "Invalid LCN < -1 in "
- "mapping pairs array.");
- goto err_out;
- }
- /* Enter the current lcn into the runlist element. */
- rl[rlpos].lcn = lcn;
- }
- /* Get to the next runlist element. */
- rlpos++;
- /* Increment the buffer position to the next mapping pair. */
- buf += (*buf & 0xf) + ((*buf >> 4) & 0xf) + 1;
- }
- if (unlikely(buf >= attr_end))
- goto io_error;
- /*
- * If there is a highest_vcn specified, it must be equal to the final
- * vcn in the runlist - 1, or something has gone badly wrong.
- */
- deltaxcn = sle64_to_cpu(attr->data.non_resident.highest_vcn);
- if (unlikely(deltaxcn && vcn - 1 != deltaxcn)) {
-mpa_err:
- ntfs_error(vol->sb, "Corrupt mapping pairs array in "
- "non-resident attribute.");
- goto err_out;
- }
- /* Setup not mapped runlist element if this is the base extent. */
- if (!attr->data.non_resident.lowest_vcn) {
- VCN max_cluster;
-
- max_cluster = ((sle64_to_cpu(
- attr->data.non_resident.allocated_size) +
- vol->cluster_size - 1) >>
- vol->cluster_size_bits) - 1;
- /*
- * A highest_vcn of zero means this is a single extent
- * attribute so simply terminate the runlist with LCN_ENOENT).
- */
- if (deltaxcn) {
- /*
- * If there is a difference between the highest_vcn and
- * the highest cluster, the runlist is either corrupt
- * or, more likely, there are more extents following
- * this one.
- */
- if (deltaxcn < max_cluster) {
- ntfs_debug("More extents to follow; deltaxcn "
- "= 0x%llx, max_cluster = "
- "0x%llx",
- (unsigned long long)deltaxcn,
- (unsigned long long)
- max_cluster);
- rl[rlpos].vcn = vcn;
- vcn += rl[rlpos].length = max_cluster -
- deltaxcn;
- rl[rlpos].lcn = LCN_RL_NOT_MAPPED;
- rlpos++;
- } else if (unlikely(deltaxcn > max_cluster)) {
- ntfs_error(vol->sb, "Corrupt attribute. "
- "deltaxcn = 0x%llx, "
- "max_cluster = 0x%llx",
- (unsigned long long)deltaxcn,
- (unsigned long long)
- max_cluster);
- goto mpa_err;
- }
- }
- rl[rlpos].lcn = LCN_ENOENT;
- } else /* Not the base extent. There may be more extents to follow. */
- rl[rlpos].lcn = LCN_RL_NOT_MAPPED;
-
- /* Setup terminating runlist element. */
- rl[rlpos].vcn = vcn;
- rl[rlpos].length = (s64)0;
- /* If no existing runlist was specified, we are done. */
- if (!old_rl) {
- ntfs_debug("Mapping pairs array successfully decompressed:");
- ntfs_debug_dump_runlist(rl);
- return rl;
- }
- /* Now combine the new and old runlists checking for overlaps. */
- old_rl = ntfs_runlists_merge(old_rl, rl);
- if (!IS_ERR(old_rl))
- return old_rl;
- ntfs_free(rl);
- ntfs_error(vol->sb, "Failed to merge runlists.");
- return old_rl;
-io_error:
- ntfs_error(vol->sb, "Corrupt attribute.");
-err_out:
- ntfs_free(rl);
- return ERR_PTR(-EIO);
-}
-
-/**
- * ntfs_rl_vcn_to_lcn - convert a vcn into a lcn given a runlist
- * @rl: runlist to use for conversion
- * @vcn: vcn to convert
- *
- * Convert the virtual cluster number @vcn of an attribute into a logical
- * cluster number (lcn) of a device using the runlist @rl to map vcns to their
- * corresponding lcns.
- *
- * It is up to the caller to serialize access to the runlist @rl.
- *
- * Since lcns must be >= 0, we use negative return codes with special meaning:
- *
- * Return code Meaning / Description
- * ==================================================
- * LCN_HOLE Hole / not allocated on disk.
- * LCN_RL_NOT_MAPPED This is part of the runlist which has not been
- * inserted into the runlist yet.
- * LCN_ENOENT There is no such vcn in the attribute.
- *
- * Locking: - The caller must have locked the runlist (for reading or writing).
- * - This function does not touch the lock, nor does it modify the
- * runlist.
- */
-LCN ntfs_rl_vcn_to_lcn(const runlist_element *rl, const VCN vcn)
-{
- int i;
-
- BUG_ON(vcn < 0);
- /*
- * If rl is NULL, assume that we have found an unmapped runlist. The
- * caller can then attempt to map it and fail appropriately if
- * necessary.
- */
- if (unlikely(!rl))
- return LCN_RL_NOT_MAPPED;
-
- /* Catch out of lower bounds vcn. */
- if (unlikely(vcn < rl[0].vcn))
- return LCN_ENOENT;
-
- for (i = 0; likely(rl[i].length); i++) {
- if (unlikely(vcn < rl[i+1].vcn)) {
- if (likely(rl[i].lcn >= (LCN)0))
- return rl[i].lcn + (vcn - rl[i].vcn);
- return rl[i].lcn;
- }
- }
- /*
- * The terminator element is setup to the correct value, i.e. one of
- * LCN_HOLE, LCN_RL_NOT_MAPPED, or LCN_ENOENT.
- */
- if (likely(rl[i].lcn < (LCN)0))
- return rl[i].lcn;
- /* Just in case... We could replace this with BUG() some day. */
- return LCN_ENOENT;
-}
-
-#ifdef NTFS_RW
-
-/**
- * ntfs_rl_find_vcn_nolock - find a vcn in a runlist
- * @rl: runlist to search
- * @vcn: vcn to find
- *
- * Find the virtual cluster number @vcn in the runlist @rl and return the
- * address of the runlist element containing the @vcn on success.
- *
- * Return NULL if @rl is NULL or @vcn is in an unmapped part/out of bounds of
- * the runlist.
- *
- * Locking: The runlist must be locked on entry.
- */
-runlist_element *ntfs_rl_find_vcn_nolock(runlist_element *rl, const VCN vcn)
-{
- BUG_ON(vcn < 0);
- if (unlikely(!rl || vcn < rl[0].vcn))
- return NULL;
- while (likely(rl->length)) {
- if (unlikely(vcn < rl[1].vcn)) {
- if (likely(rl->lcn >= LCN_HOLE))
- return rl;
- return NULL;
- }
- rl++;
- }
- if (likely(rl->lcn == LCN_ENOENT))
- return rl;
- return NULL;
-}
-
-/**
- * ntfs_get_nr_significant_bytes - get number of bytes needed to store a number
- * @n: number for which to get the number of bytes for
- *
- * Return the number of bytes required to store @n unambiguously as
- * a signed number.
- *
- * This is used in the context of the mapping pairs array to determine how
- * many bytes will be needed in the array to store a given logical cluster
- * number (lcn) or a specific run length.
- *
- * Return the number of bytes written. This function cannot fail.
- */
-static inline int ntfs_get_nr_significant_bytes(const s64 n)
-{
- s64 l = n;
- int i;
- s8 j;
-
- i = 0;
- do {
- l >>= 8;
- i++;
- } while (l != 0 && l != -1);
- j = (n >> 8 * (i - 1)) & 0xff;
- /* If the sign bit is wrong, we need an extra byte. */
- if ((n < 0 && j >= 0) || (n > 0 && j < 0))
- i++;
- return i;
-}
-
-/**
- * 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
- * @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 @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.
- *
- * If @rl is NULL, just return 1 (for the single terminator byte).
- *
- * Return the calculated size in bytes on success. On error, return -errno.
- * The following error codes are defined:
- * -EINVAL - Run list contains unmapped elements. Make sure to only pass
- * fully mapped runlists to this function.
- * -EIO - The runlist is corrupt.
- *
- * Locking: @rl must be locked on entry (either for reading or writing), it
- * 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 first_vcn,
- const VCN last_vcn)
-{
- LCN prev_lcn;
- int rls;
- bool the_end = false;
-
- BUG_ON(first_vcn < 0);
- BUG_ON(last_vcn < -1);
- BUG_ON(last_vcn >= 0 && first_vcn > last_vcn);
- if (!rl) {
- BUG_ON(first_vcn);
- BUG_ON(last_vcn > 0);
- return 1;
- }
- /* Skip to runlist element containing @first_vcn. */
- while (rl->length && first_vcn >= rl[1].vcn)
- rl++;
- 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 (first_vcn > rl->vcn) {
- s64 delta, length = rl->length;
-
- /* We know rl->length != 0 already. */
- 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;
- }
- delta = first_vcn - rl->vcn;
- /* Header byte + length. */
- 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
- * zero space. On earlier NTFS versions we just store the lcn.
- * 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 (likely(rl->lcn >= 0 || vol->major_ver < 3)) {
- prev_lcn = rl->lcn;
- if (likely(rl->lcn >= 0))
- prev_lcn += delta;
- /* Change in lcn. */
- rls += ntfs_get_nr_significant_bytes(prev_lcn);
- }
- /* Go to next runlist element. */
- rl++;
- }
- /* Do the full runs. */
- 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(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
- * zero space. On earlier NTFS versions we just store the lcn.
- * 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 (likely(rl->lcn >= 0 || vol->major_ver < 3)) {
- /* Change in lcn. */
- rls += ntfs_get_nr_significant_bytes(rl->lcn -
- prev_lcn);
- prev_lcn = rl->lcn;
- }
- }
- return rls;
-err_out:
- if (rl->lcn == LCN_RL_NOT_MAPPED)
- rls = -EINVAL;
- else
- rls = -EIO;
- return rls;
-}
-
-/**
- * ntfs_write_significant_bytes - write the significant bytes of a number
- * @dst: destination buffer to write to
- * @dst_max: pointer to last byte of destination buffer for bounds checking
- * @n: number whose significant bytes to write
- *
- * Store in @dst, the minimum bytes of the number @n which are required to
- * identify @n unambiguously as a signed number, taking care not to exceed
- * @dest_max, the maximum position within @dst to which we are allowed to
- * write.
- *
- * This is used when building the mapping pairs array of a runlist to compress
- * a given logical cluster number (lcn) or a specific run length to the minimum
- * size possible.
- *
- * Return the number of bytes written on success. On error, i.e. the
- * destination buffer @dst is too small, return -ENOSPC.
- */
-static inline int ntfs_write_significant_bytes(s8 *dst, const s8 *dst_max,
- const s64 n)
-{
- s64 l = n;
- int i;
- s8 j;
-
- i = 0;
- do {
- if (unlikely(dst > dst_max))
- goto err_out;
- *dst++ = l & 0xffll;
- l >>= 8;
- i++;
- } while (l != 0 && l != -1);
- j = (n >> 8 * (i - 1)) & 0xff;
- /* If the sign bit is wrong, we need an extra byte. */
- if (n < 0 && j >= 0) {
- if (unlikely(dst > dst_max))
- goto err_out;
- i++;
- *dst = (s8)-1;
- } else if (n > 0 && j < 0) {
- if (unlikely(dst > dst_max))
- goto err_out;
- i++;
- *dst = (s8)0;
- }
- return i;
-err_out:
- return -ENOSPC;
-}
-
-/**
- * ntfs_mapping_pairs_build - build the mapping pairs array from a runlist
- * @vol: ntfs volume (needed for the ntfs version)
- * @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
- * @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
- * @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.
- *
- * On success or -ENOSPC error, if @stop_vcn is not NULL, *@stop_vcn is set to
- * the first vcn outside the destination buffer. Note that on error, @dst has
- * 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 @first_vcn set to *@stop_vcn.
- *
- * Return 0 on success and -errno on error. The following error codes are
- * defined:
- * -EINVAL - Run list contains unmapped elements. Make sure to only pass
- * fully mapped runlists to this function.
- * -EIO - The runlist is corrupt.
- * -ENOSPC - The destination buffer is too small.
- *
- * Locking: @rl must be locked on entry (either for reading or writing), it
- * remains locked throughout, and is left locked upon return.
- */
-int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
- const int dst_len, const runlist_element *rl,
- 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(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(first_vcn);
- BUG_ON(last_vcn > 0);
- if (stop_vcn)
- *stop_vcn = 0;
- /* Terminator byte. */
- *dst = 0;
- return 0;
- }
- /* Skip to runlist element containing @first_vcn. */
- while (rl->length && first_vcn >= rl[1].vcn)
- rl++;
- if (unlikely((!rl->length && first_vcn > rl->vcn) ||
- first_vcn < rl->vcn))
- return -EINVAL;
- /*
- * @dst_max is used for bounds checking in
- * ntfs_write_significant_bytes().
- */
- dst_max = dst + dst_len - 1;
- prev_lcn = 0;
- /* Do the first partial run if present. */
- if (first_vcn > rl->vcn) {
- s64 delta, length = rl->length;
-
- /* We know rl->length != 0 already. */
- 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;
- }
- delta = first_vcn - rl->vcn;
- /* Write length. */
- len_len = ntfs_write_significant_bytes(dst + 1, dst_max,
- length - delta);
- if (unlikely(len_len < 0))
- goto size_err;
- /*
- * 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
- * zero space. On earlier NTFS versions we just write the lcn
- * change. FIXME: Do we need to write the lcn change or just
- * the lcn in that case? Not sure as I have never seen this
- * case on NT4. - We assume that we just need to write the lcn
- * change until someone tells us otherwise... (AIA)
- */
- if (likely(rl->lcn >= 0 || vol->major_ver < 3)) {
- prev_lcn = rl->lcn;
- 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 (unlikely(lcn_len < 0))
- goto size_err;
- } else
- lcn_len = 0;
- dst_next = dst + len_len + lcn_len + 1;
- if (unlikely(dst_next > dst_max))
- goto size_err;
- /* Update header byte. */
- *dst = lcn_len << 4 | len_len;
- /* Position at next mapping pairs array element. */
- dst = dst_next;
- /* Go to next runlist element. */
- rl++;
- }
- /* Do the full runs. */
- 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,
- length);
- if (unlikely(len_len < 0))
- goto size_err;
- /*
- * 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
- * zero space. On earlier NTFS versions we just write the lcn
- * change. FIXME: Do we need to write the lcn change or just
- * the lcn in that case? Not sure as I have never seen this
- * case on NT4. - We assume that we just need to write the lcn
- * change until someone tells us otherwise... (AIA)
- */
- 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 (unlikely(lcn_len < 0))
- goto size_err;
- prev_lcn = rl->lcn;
- } else
- lcn_len = 0;
- dst_next = dst + len_len + lcn_len + 1;
- if (unlikely(dst_next > dst_max))
- goto size_err;
- /* Update header byte. */
- *dst = lcn_len << 4 | len_len;
- /* Position at next mapping pairs array element. */
- dst = dst_next;
- }
- /* Success. */
- err = 0;
-size_err:
- /* Set stop vcn. */
- if (stop_vcn)
- *stop_vcn = rl->vcn;
- /* Add terminator byte. */
- *dst = 0;
- return err;
-err_out:
- if (rl->lcn == LCN_RL_NOT_MAPPED)
- err = -EINVAL;
- else
- err = -EIO;
- return err;
-}
-
-/**
- * ntfs_rl_truncate_nolock - truncate a runlist starting at a specified vcn
- * @vol: ntfs volume (needed for error output)
- * @runlist: runlist to truncate
- * @new_length: the new length of the runlist in VCNs
- *
- * Truncate the runlist described by @runlist as well as the memory buffer
- * holding the runlist elements to a length of @new_length VCNs.
- *
- * If @new_length lies within the runlist, the runlist elements with VCNs of
- * @new_length and above are discarded. As a special case if @new_length is
- * zero, the runlist is discarded and set to NULL.
- *
- * If @new_length lies beyond the runlist, a sparse runlist element is added to
- * the end of the runlist @runlist or if the last runlist element is a sparse
- * one already, this is extended.
- *
- * Note, no checking is done for unmapped runlist elements. It is assumed that
- * the caller has mapped any elements that need to be mapped already.
- *
- * Return 0 on success and -errno on error.
- *
- * Locking: The caller must hold @runlist->lock for writing.
- */
-int ntfs_rl_truncate_nolock(const ntfs_volume *vol, runlist *const runlist,
- const s64 new_length)
-{
- runlist_element *rl;
- int old_size;
-
- ntfs_debug("Entering for new_length 0x%llx.", (long long)new_length);
- BUG_ON(!runlist);
- BUG_ON(new_length < 0);
- rl = runlist->rl;
- if (!new_length) {
- ntfs_debug("Freeing runlist.");
- runlist->rl = NULL;
- if (rl)
- ntfs_free(rl);
- return 0;
- }
- if (unlikely(!rl)) {
- /*
- * Create a runlist consisting of a sparse runlist element of
- * length @new_length followed by a terminator runlist element.
- */
- rl = ntfs_malloc_nofs(PAGE_SIZE);
- if (unlikely(!rl)) {
- ntfs_error(vol->sb, "Not enough memory to allocate "
- "runlist element buffer.");
- return -ENOMEM;
- }
- runlist->rl = rl;
- rl[1].length = rl->vcn = 0;
- rl->lcn = LCN_HOLE;
- rl[1].vcn = rl->length = new_length;
- rl[1].lcn = LCN_ENOENT;
- return 0;
- }
- BUG_ON(new_length < rl->vcn);
- /* Find @new_length in the runlist. */
- while (likely(rl->length && new_length >= rl[1].vcn))
- rl++;
- /*
- * If not at the end of the runlist we need to shrink it.
- * If at the end of the runlist we need to expand it.
- */
- if (rl->length) {
- runlist_element *trl;
- bool is_end;
-
- ntfs_debug("Shrinking runlist.");
- /* Determine the runlist size. */
- trl = rl + 1;
- while (likely(trl->length))
- trl++;
- old_size = trl - runlist->rl + 1;
- /* Truncate the run. */
- rl->length = new_length - rl->vcn;
- /*
- * If a run was partially truncated, make the following runlist
- * element a terminator.
- */
- is_end = false;
- if (rl->length) {
- rl++;
- if (!rl->length)
- is_end = true;
- rl->vcn = new_length;
- rl->length = 0;
- }
- rl->lcn = LCN_ENOENT;
- /* Reallocate memory if necessary. */
- if (!is_end) {
- int new_size = rl - runlist->rl + 1;
- rl = ntfs_rl_realloc(runlist->rl, old_size, new_size);
- if (IS_ERR(rl))
- ntfs_warning(vol->sb, "Failed to shrink "
- "runlist buffer. This just "
- "wastes a bit of memory "
- "temporarily so we ignore it "
- "and return success.");
- else
- runlist->rl = rl;
- }
- } else if (likely(/* !rl->length && */ new_length > rl->vcn)) {
- ntfs_debug("Expanding runlist.");
- /*
- * If there is a previous runlist element and it is a sparse
- * one, extend it. Otherwise need to add a new, sparse runlist
- * element.
- */
- if ((rl > runlist->rl) && ((rl - 1)->lcn == LCN_HOLE))
- (rl - 1)->length = new_length - (rl - 1)->vcn;
- else {
- /* Determine the runlist size. */
- old_size = rl - runlist->rl + 1;
- /* Reallocate memory if necessary. */
- rl = ntfs_rl_realloc(runlist->rl, old_size,
- old_size + 1);
- if (IS_ERR(rl)) {
- ntfs_error(vol->sb, "Failed to expand runlist "
- "buffer, aborting.");
- return PTR_ERR(rl);
- }
- runlist->rl = rl;
- /*
- * Set @rl to the same runlist element in the new
- * runlist as before in the old runlist.
- */
- rl += old_size - 1;
- /* Add a new, sparse runlist element. */
- rl->lcn = LCN_HOLE;
- rl->length = new_length - rl->vcn;
- /* Add a new terminator runlist element. */
- rl++;
- rl->length = 0;
- }
- rl->vcn = new_length;
- rl->lcn = LCN_ENOENT;
- } else /* if (unlikely(!rl->length && new_length == rl->vcn)) */ {
- /* Runlist already has same size as requested. */
- rl->lcn = LCN_ENOENT;
- }
- ntfs_debug("Done.");
- return 0;
-}
-
-/**
- * ntfs_rl_punch_nolock - punch a hole into a runlist
- * @vol: ntfs volume (needed for error output)
- * @runlist: runlist to punch a hole into
- * @start: starting VCN of the hole to be created
- * @length: size of the hole to be created in units of clusters
- *
- * Punch a hole into the runlist @runlist starting at VCN @start and of size
- * @length clusters.
- *
- * Return 0 on success and -errno on error, in which case @runlist has not been
- * modified.
- *
- * If @start and/or @start + @length are outside the runlist return error code
- * -ENOENT.
- *
- * If the runlist contains unmapped or error elements between @start and @start
- * + @length return error code -EINVAL.
- *
- * Locking: The caller must hold @runlist->lock for writing.
- */
-int ntfs_rl_punch_nolock(const ntfs_volume *vol, runlist *const runlist,
- const VCN start, const s64 length)
-{
- const VCN end = start + length;
- s64 delta;
- runlist_element *rl, *rl_end, *rl_real_end, *trl;
- int old_size;
- bool lcn_fixup = false;
-
- ntfs_debug("Entering for start 0x%llx, length 0x%llx.",
- (long long)start, (long long)length);
- BUG_ON(!runlist);
- BUG_ON(start < 0);
- BUG_ON(length < 0);
- BUG_ON(end < 0);
- rl = runlist->rl;
- if (unlikely(!rl)) {
- if (likely(!start && !length))
- return 0;
- return -ENOENT;
- }
- /* Find @start in the runlist. */
- while (likely(rl->length && start >= rl[1].vcn))
- rl++;
- rl_end = rl;
- /* Find @end in the runlist. */
- while (likely(rl_end->length && end >= rl_end[1].vcn)) {
- /* Verify there are no unmapped or error elements. */
- if (unlikely(rl_end->lcn < LCN_HOLE))
- return -EINVAL;
- rl_end++;
- }
- /* Check the last element. */
- if (unlikely(rl_end->length && rl_end->lcn < LCN_HOLE))
- return -EINVAL;
- /* This covers @start being out of bounds, too. */
- if (!rl_end->length && end > rl_end->vcn)
- return -ENOENT;
- if (!length)
- return 0;
- if (!rl->length)
- return -ENOENT;
- rl_real_end = rl_end;
- /* Determine the runlist size. */
- while (likely(rl_real_end->length))
- rl_real_end++;
- old_size = rl_real_end - runlist->rl + 1;
- /* If @start is in a hole simply extend the hole. */
- if (rl->lcn == LCN_HOLE) {
- /*
- * If both @start and @end are in the same sparse run, we are
- * done.
- */
- if (end <= rl[1].vcn) {
- ntfs_debug("Done (requested hole is already sparse).");
- return 0;
- }
-extend_hole:
- /* Extend the hole. */
- rl->length = end - rl->vcn;
- /* If @end is in a hole, merge it with the current one. */
- if (rl_end->lcn == LCN_HOLE) {
- rl_end++;
- rl->length = rl_end->vcn - rl->vcn;
- }
- /* We have done the hole. Now deal with the remaining tail. */
- rl++;
- /* Cut out all runlist elements up to @end. */
- if (rl < rl_end)
- memmove(rl, rl_end, (rl_real_end - rl_end + 1) *
- sizeof(*rl));
- /* Adjust the beginning of the tail if necessary. */
- if (end > rl->vcn) {
- delta = end - rl->vcn;
- rl->vcn = end;
- rl->length -= delta;
- /* Only adjust the lcn if it is real. */
- if (rl->lcn >= 0)
- rl->lcn += delta;
- }
-shrink_allocation:
- /* Reallocate memory if the allocation changed. */
- if (rl < rl_end) {
- rl = ntfs_rl_realloc(runlist->rl, old_size,
- old_size - (rl_end - rl));
- if (IS_ERR(rl))
- ntfs_warning(vol->sb, "Failed to shrink "
- "runlist buffer. This just "
- "wastes a bit of memory "
- "temporarily so we ignore it "
- "and return success.");
- else
- runlist->rl = rl;
- }
- ntfs_debug("Done (extend hole).");
- return 0;
- }
- /*
- * If @start is at the beginning of a run things are easier as there is
- * no need to split the first run.
- */
- if (start == rl->vcn) {
- /*
- * @start is at the beginning of a run.
- *
- * If the previous run is sparse, extend its hole.
- *
- * If @end is not in the same run, switch the run to be sparse
- * and extend the newly created hole.
- *
- * Thus both of these cases reduce the problem to the above
- * case of "@start is in a hole".
- */
- if (rl > runlist->rl && (rl - 1)->lcn == LCN_HOLE) {
- rl--;
- goto extend_hole;
- }
- if (end >= rl[1].vcn) {
- rl->lcn = LCN_HOLE;
- goto extend_hole;
- }
- /*
- * The final case is when @end is in the same run as @start.
- * For this need to split the run into two. One run for the
- * sparse region between the beginning of the old run, i.e.
- * @start, and @end and one for the remaining non-sparse
- * region, i.e. between @end and the end of the old run.
- */
- trl = ntfs_rl_realloc(runlist->rl, old_size, old_size + 1);
- if (IS_ERR(trl))
- goto enomem_out;
- old_size++;
- if (runlist->rl != trl) {
- rl = trl + (rl - runlist->rl);
- rl_end = trl + (rl_end - runlist->rl);
- rl_real_end = trl + (rl_real_end - runlist->rl);
- runlist->rl = trl;
- }
-split_end:
- /* Shift all the runs up by one. */
- memmove(rl + 1, rl, (rl_real_end - rl + 1) * sizeof(*rl));
- /* Finally, setup the two split runs. */
- rl->lcn = LCN_HOLE;
- rl->length = length;
- rl++;
- rl->vcn += length;
- /* Only adjust the lcn if it is real. */
- if (rl->lcn >= 0 || lcn_fixup)
- rl->lcn += length;
- rl->length -= length;
- ntfs_debug("Done (split one).");
- return 0;
- }
- /*
- * @start is neither in a hole nor at the beginning of a run.
- *
- * If @end is in a hole, things are easier as simply truncating the run
- * @start is in to end at @start - 1, deleting all runs after that up
- * to @end, and finally extending the beginning of the run @end is in
- * to be @start is all that is needed.
- */
- if (rl_end->lcn == LCN_HOLE) {
- /* Truncate the run containing @start. */
- rl->length = start - rl->vcn;
- rl++;
- /* Cut out all runlist elements up to @end. */
- if (rl < rl_end)
- memmove(rl, rl_end, (rl_real_end - rl_end + 1) *
- sizeof(*rl));
- /* Extend the beginning of the run @end is in to be @start. */
- rl->vcn = start;
- rl->length = rl[1].vcn - start;
- goto shrink_allocation;
- }
- /*
- * If @end is not in a hole there are still two cases to distinguish.
- * Either @end is or is not in the same run as @start.
- *
- * The second case is easier as it can be reduced to an already solved
- * problem by truncating the run @start is in to end at @start - 1.
- * Then, if @end is in the next run need to split the run into a sparse
- * run followed by a non-sparse run (already covered above) and if @end
- * is not in the next run switching it to be sparse, again reduces the
- * problem to the already covered case of "@start is in a hole".
- */
- if (end >= rl[1].vcn) {
- /*
- * If @end is not in the next run, reduce the problem to the
- * case of "@start is in a hole".
- */
- if (rl[1].length && end >= rl[2].vcn) {
- /* Truncate the run containing @start. */
- rl->length = start - rl->vcn;
- rl++;
- rl->vcn = start;
- rl->lcn = LCN_HOLE;
- goto extend_hole;
- }
- trl = ntfs_rl_realloc(runlist->rl, old_size, old_size + 1);
- if (IS_ERR(trl))
- goto enomem_out;
- old_size++;
- if (runlist->rl != trl) {
- rl = trl + (rl - runlist->rl);
- rl_end = trl + (rl_end - runlist->rl);
- rl_real_end = trl + (rl_real_end - runlist->rl);
- runlist->rl = trl;
- }
- /* Truncate the run containing @start. */
- rl->length = start - rl->vcn;
- rl++;
- /*
- * @end is in the next run, reduce the problem to the case
- * where "@start is at the beginning of a run and @end is in
- * the same run as @start".
- */
- delta = rl->vcn - start;
- rl->vcn = start;
- if (rl->lcn >= 0) {
- rl->lcn -= delta;
- /* Need this in case the lcn just became negative. */
- lcn_fixup = true;
- }
- rl->length += delta;
- goto split_end;
- }
- /*
- * The first case from above, i.e. @end is in the same run as @start.
- * We need to split the run into three. One run for the non-sparse
- * region between the beginning of the old run and @start, one for the
- * sparse region between @start and @end, and one for the remaining
- * non-sparse region, i.e. between @end and the end of the old run.
- */
- trl = ntfs_rl_realloc(runlist->rl, old_size, old_size + 2);
- if (IS_ERR(trl))
- goto enomem_out;
- old_size += 2;
- if (runlist->rl != trl) {
- rl = trl + (rl - runlist->rl);
- rl_end = trl + (rl_end - runlist->rl);
- rl_real_end = trl + (rl_real_end - runlist->rl);
- runlist->rl = trl;
- }
- /* Shift all the runs up by two. */
- memmove(rl + 2, rl, (rl_real_end - rl + 1) * sizeof(*rl));
- /* Finally, setup the three split runs. */
- rl->length = start - rl->vcn;
- rl++;
- rl->vcn = start;
- rl->lcn = LCN_HOLE;
- rl->length = length;
- rl++;
- delta = end - rl->vcn;
- rl->vcn = end;
- rl->lcn += delta;
- rl->length -= delta;
- ntfs_debug("Done (split both).");
- return 0;
-enomem_out:
- ntfs_error(vol->sb, "Not enough memory to extend runlist buffer.");
- return -ENOMEM;
-}
-
-#endif /* NTFS_RW */