/**
- * attrib.c - NTFS attribute operations. Part of the Linux-NTFS project.
+ * attrib.c - NTFS attribute operations. Part of the Linux-NTFS project.
*
* Copyright (c) 2001-2004 Anton Altaparmakov
* Copyright (c) 2002 Richard Russon
*/
#include <linux/buffer_head.h>
-#include "ntfs.h"
-#include "dir.h"
-
-/* Temporary helper functions -- might become macros */
-
-/**
- * ntfs_rl_mm - run_list memmove
- *
- * It is up to the caller to serialize access to the run list @base.
- */
-static inline void ntfs_rl_mm(run_list_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 - run_list memory copy
- *
- * It is up to the caller to serialize access to the run lists @dstbase and
- * @srcbase.
- */
-static inline void ntfs_rl_mc(run_list_element *dstbase, int dst,
- run_list_element *srcbase, int src, int size)
-{
- if (likely(size > 0))
- memcpy(dstbase + dst, srcbase + src, size * sizeof(*dstbase));
-}
-
-/**
- * ntfs_rl_realloc - Reallocate memory for run_lists
- * @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 @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 run list array.
- * -EINVAL - Invalid parameters were passed in.
- */
-static inline run_list_element *ntfs_rl_realloc(run_list_element *rl,
- int old_size, int new_size)
-{
- run_list_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_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
- *
- * 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 @dst and @src.
- *
- * Return: TRUE Success, the run lists can be merged.
- * FALSE Failure, the run lists cannot be merged.
- */
-static inline BOOL ntfs_are_rl_mergeable(run_list_element *dst,
- run_list_element *src)
-{
- BUG_ON(!dst);
- BUG_ON(!src);
-
- if ((dst->lcn < 0) || (src->lcn < 0)) /* Are we merging holes? */
- return FALSE;
- if ((dst->lcn + dst->length) != src->lcn) /* Are the runs contiguous? */
- return FALSE;
- if ((dst->vcn + dst->length) != src->vcn) /* Are the runs misaligned? */
- return FALSE;
-
- return TRUE;
-}
-
-/**
- * __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
- *
- * 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 @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
- *
- * 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.
- *
- * 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 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)
-{
- BOOL right;
- int magic;
-
- BUG_ON(!dst);
- BUG_ON(!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. */
- if (right)
- __ntfs_rl_merge(src + ssize - 1, dst + loc + 1);
-
- magic = loc + ssize;
-
- /* 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. */
- 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[magic + 1].lcn == LCN_ENOENT)
- dst[magic + 1].vcn = dst[magic].vcn + dst[magic].length;
-
- return dst;
-}
-
-/**
- * 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 *dst,
- int dsize, run_list_element *src, int ssize, int loc)
-{
- BOOL left = FALSE;
- BOOL disc = FALSE; /* Discontinuity */
- BOOL hole = FALSE; /* Following a hole */
- int magic;
-
- 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 hole.
- * hole => @dst ends with a hole or an unmapped region which we can
- * extend to match the discontinuity. */
- 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);
- if (disc)
- hole = (dst[loc - 1].lcn == LCN_HOLE);
- }
-
- /* 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);
-
- 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 (dst[magic].lcn <= LCN_HOLE)
- dst[magic].vcn = dst[magic - 1].vcn + dst[magic - 1].length;
- /* ... and the length. */
- 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)
- dst[loc - 1].length = dst[loc].vcn - dst[loc - 1].vcn;
- else {
- 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;
- }
-
- magic += hole;
-
- 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
- * @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 *dst,
- int dsize, run_list_element *src, int ssize, int loc)
-{
- BOOL left = FALSE;
- BOOL right;
- int magic;
-
- BUG_ON(!dst);
- BUG_ON(!src);
-
- /* First, merge the left and right ends, if necessary. */
- 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'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);
-
- /* FIXME: What does this mean? (AIA) */
- magic = loc + ssize - 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 (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
- * @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 *dst, int dsize,
- run_list_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 run lists.
- */
-
- /* 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_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 @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.
- *
- * Merging of run lists 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 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 *ntfs_merge_run_lists(run_list_element *drl,
- run_list_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 (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)) {
- drl = srl;
- /* Complete the source run list if necessary. */
- if (unlikely(drl[0].vcn)) {
- /* Scan to the end of the source run list. */
- for (dend = 0; likely(drl[dend].length); dend++)
- ;
- 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 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 source run list. */
- 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 run lists 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)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'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))
- 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.\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;
- }
- }
- }
-
-finished:
- /* 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
- * @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.
- *
- * 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 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; /* 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. */
- u16 rlpos; /* Current run list position in units of
- run_list_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);
- }
- /* Current position in run list array. */
- rlpos = 0;
- /* 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);
- /* Insert unmapped starting element if necessary. */
- if (vcn) {
- rl->vcn = (VCN)0;
- rl->lcn = (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) {
- run_list_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 run_list 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 run list
- * 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)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 run_list element. */
- rl[rlpos].lcn = lcn;
- }
- /* Get to the next run_list 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 run list - 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 run list 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;
- /*
- * If there is a difference between the highest_vcn and the
- * highest cluster, the run list 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)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)LCN_ENOENT;
- } else /* Not the base extent. There may be more extents to follow. */
- rl[rlpos].lcn = (LCN)LCN_RL_NOT_MAPPED;
- /* Setup terminating run_list element. */
- rl[rlpos].vcn = vcn;
- rl[rlpos].length = (s64)0;
- /* If no existing run list 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 run lists checking for overlaps. */
- 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 old_rl;
-io_error:
- ntfs_error(vol->sb, "Corrupt attribute.");
-err_out:
- ntfs_free(rl);
- return ERR_PTR(-EIO);
-}
+#include "attrib.h"
+#include "debug.h"
+#include "layout.h"
+#include "mft.h"
+#include "ntfs.h"
+#include "types.h"
/**
- * map_run_list - map (a part of) a run list of an ntfs inode
- * @ni: ntfs inode for which to map (part of) a run list
- * @vcn: map run list part containing this vcn
+ * ntfs_map_runlist - map (a part of) a runlist of an ntfs inode
+ * @ni: ntfs inode for which to map (part of) a runlist
+ * @vcn: map runlist part containing this vcn
*
- * Map the part of a run list containing the @vcn of an the ntfs inode @ni.
+ * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
*
* Return 0 on success and -errno on error.
+ *
+ * Locking: - The runlist must be unlocked on entry and is unlocked on return.
+ * - This function takes the lock for writing and modifies the runlist.
*/
-int map_run_list(ntfs_inode *ni, VCN vcn)
+int ntfs_map_runlist(ntfs_inode *ni, VCN vcn)
{
ntfs_inode *base_ni;
- attr_search_context *ctx;
+ ntfs_attr_search_ctx *ctx;
MFT_RECORD *mrec;
int err = 0;
-
- ntfs_debug("Mapping run list part containing vcn 0x%llx.",
+
+ ntfs_debug("Mapping runlist part containing vcn 0x%llx.",
(unsigned long long)vcn);
if (!NInoAttr(ni))
mrec = map_mft_record(base_ni);
if (IS_ERR(mrec))
return PTR_ERR(mrec);
- ctx = get_attr_search_ctx(base_ni, mrec);
- if (!ctx) {
+ ctx = ntfs_attr_get_search_ctx(base_ni, mrec);
+ if (unlikely(!ctx)) {
err = -ENOMEM;
goto err_out;
}
- if (!lookup_attr(ni->type, ni->name, ni->name_len, IGNORE_CASE, vcn,
- NULL, 0, ctx)) {
- put_attr_search_ctx(ctx);
- err = -ENOENT;
- goto err_out;
- }
+ err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+ CASE_SENSITIVE, vcn, NULL, 0, ctx);
+ if (unlikely(err))
+ goto put_err_out;
- down_write(&ni->run_list.lock);
+ down_write(&ni->runlist.lock);
/* Make sure someone else didn't do the work while we were sleeping. */
- if (likely(vcn_to_lcn(ni->run_list.rl, vcn) <= LCN_RL_NOT_MAPPED)) {
- run_list_element *rl;
+ if (likely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) <=
+ LCN_RL_NOT_MAPPED)) {
+ runlist_element *rl;
- rl = decompress_mapping_pairs(ni->vol, ctx->attr,
- ni->run_list.rl);
- if (unlikely(IS_ERR(rl)))
+ rl = ntfs_mapping_pairs_decompress(ni->vol, ctx->attr,
+ ni->runlist.rl);
+ if (IS_ERR(rl))
err = PTR_ERR(rl);
else
- ni->run_list.rl = rl;
+ ni->runlist.rl = rl;
}
- up_write(&ni->run_list.lock);
-
- put_attr_search_ctx(ctx);
+ up_write(&ni->runlist.lock);
+
+put_err_out:
+ ntfs_attr_put_search_ctx(ctx);
err_out:
unmap_mft_record(base_ni);
return err;
}
/**
- * vcn_to_lcn - convert a vcn into a lcn given a run list
- * @rl: run list 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 run list @rl to map vcns to their
- * corresponding lcns.
- *
- * It is up to the caller to serialize access to the run list @rl.
- *
- * Since lcns must be >= 0, we use negative return values with special meaning:
- *
- * Return value Meaning / Description
- * ==================================================
- * -1 = LCN_HOLE Hole / not allocated on disk.
- * -2 = LCN_RL_NOT_MAPPED This is part of the run list which has not been
- * inserted into the run list yet.
- * -3 = LCN_ENOENT There is no such vcn in the attribute.
- * -4 = LCN_EINVAL Input parameter error (if debug enabled).
+ * ntfs_find_vcn - find a vcn in the runlist described by an ntfs inode
+ * @ni: ntfs inode describing the runlist to search
+ * @vcn: vcn to find
+ * @need_write: if false, lock for reading and if true, lock for writing
+ *
+ * Find the virtual cluster number @vcn in the runlist described by the ntfs
+ * inode @ni and return the address of the runlist element containing the @vcn.
+ * The runlist is left locked and the caller has to unlock it. If @need_write
+ * is true, the runlist is locked for writing and if @need_write is false, the
+ * runlist is locked for reading. In the error case, the runlist is not left
+ * locked.
+ *
+ * Note you need to distinguish between the lcn of the returned runlist element
+ * being >= 0 and LCN_HOLE. In the later case you have to return zeroes on
+ * read and allocate clusters on write.
+ *
+ * Return the runlist element containing the @vcn on success and
+ * ERR_PTR(-errno) on error. You need to test the return value with IS_ERR()
+ * to decide if the return is success or failure and PTR_ERR() to get to the
+ * error code if IS_ERR() is true.
+ *
+ * The possible error return codes are:
+ * -ENOENT - No such vcn in the runlist, i.e. @vcn is out of bounds.
+ * -ENOMEM - Not enough memory to map runlist.
+ * -EIO - Critical error (runlist/file is corrupt, i/o error, etc).
+ *
+ * Locking: - The runlist must be unlocked on entry.
+ * - On failing return, the runlist is unlocked.
+ * - On successful return, the runlist is locked. If @need_write us
+ * true, it is locked for writing. Otherwise is is locked for
+ * reading.
*/
-LCN vcn_to_lcn(const run_list_element *rl, const VCN vcn)
+runlist_element *ntfs_find_vcn(ntfs_inode *ni, const VCN vcn,
+ const BOOL need_write)
{
- int i;
-
-#ifdef DEBUG
- if (vcn < (VCN)0)
- return (LCN)LCN_EINVAL;
-#endif
- /*
- * If rl is NULL, assume that we have found an unmapped run list. The
- * caller can then attempt to map it and fail appropriately if
- * necessary.
- */
- if (unlikely(!rl))
- return (LCN)LCN_RL_NOT_MAPPED;
-
- /* Catch out of lower bounds vcn. */
- if (unlikely(vcn < rl[0].vcn))
- return (LCN)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;
+ runlist_element *rl;
+ int err = 0;
+ BOOL is_retry = FALSE;
+
+ ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, lock for %sing.",
+ ni->mft_no, (unsigned long long)vcn,
+ !need_write ? "read" : "writ");
+ BUG_ON(!ni);
+ BUG_ON(!NInoNonResident(ni));
+ BUG_ON(vcn < 0);
+lock_retry_remap:
+ if (!need_write)
+ down_read(&ni->runlist.lock);
+ else
+ down_write(&ni->runlist.lock);
+ rl = ni->runlist.rl;
+ if (likely(rl && vcn >= rl[0].vcn)) {
+ while (likely(rl->length)) {
+ if (likely(vcn < rl[1].vcn)) {
+ if (likely(rl->lcn >= LCN_HOLE)) {
+ ntfs_debug("Done.");
+ return rl;
+ }
+ break;
+ }
+ rl++;
+ }
+ if (likely(rl->lcn != LCN_RL_NOT_MAPPED)) {
+ if (likely(rl->lcn == LCN_ENOENT))
+ err = -ENOENT;
+ else
+ err = -EIO;
}
}
- /*
- * 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)LCN_ENOENT;
+ if (!need_write)
+ up_read(&ni->runlist.lock);
+ else
+ up_write(&ni->runlist.lock);
+ if (!err && !is_retry) {
+ /*
+ * The @vcn is in an unmapped region, map the runlist and
+ * retry.
+ */
+ err = ntfs_map_runlist(ni, vcn);
+ if (likely(!err)) {
+ is_retry = TRUE;
+ goto lock_retry_remap;
+ }
+ /*
+ * -EINVAL and -ENOENT coming from a failed mapping attempt are
+ * equivalent to i/o errors for us as they should not happen in
+ * our code paths.
+ */
+ if (err == -EINVAL || err == -ENOENT)
+ err = -EIO;
+ } else if (!err)
+ err = -EIO;
+ ntfs_error(ni->vol->sb, "Failed with error code %i.", err);
+ return ERR_PTR(err);
}
/**
- * find_attr - find (next) attribute in mft record
+ * ntfs_attr_find - find (next) attribute in mft record
* @type: attribute type to find
* @name: attribute name to find (optional, i.e. NULL means don't care)
* @name_len: attribute name length (only needed if @name present)
* @val_len: attribute value length
* @ctx: search context with mft record and attribute to search from
*
- * You shouldn't need to call this function directly. Use lookup_attr() instead.
+ * You should not need to call this function directly. Use ntfs_attr_lookup()
+ * instead.
+ *
+ * ntfs_attr_find() takes a search context @ctx as parameter and searches the
+ * mft record specified by @ctx->mrec, beginning at @ctx->attr, for an
+ * attribute of @type, optionally @name and @val.
*
- * find_attr() takes a search context @ctx as parameter and searches the mft
- * record specified by @ctx->mrec, beginning at @ctx->attr, for an attribute of
- * @type, optionally @name and @val. If found, find_attr() returns TRUE and
- * @ctx->attr will point to the found attribute. If not found, find_attr()
- * returns FALSE and @ctx->attr is undefined (i.e. do not rely on it not
- * changing).
+ * If the attribute is found, ntfs_attr_find() returns 0 and @ctx->attr will
+ * point to the found attribute.
*
- * If @ctx->is_first is TRUE, the search begins with @ctx->attr itself. If it
+ * If the attribute is not found, ntfs_attr_find() returns -ENOENT and
+ * @ctx->attr will point to the attribute before which the attribute being
+ * searched for would need to be inserted if such an action were to be desired.
+ *
+ * On actual error, ntfs_attr_find() returns -EIO. In this case @ctx->attr is
+ * undefined and in particular do not rely on it not changing.
+ *
+ * If @ctx->is_first is TRUE, the search begins with @ctx->attr itself. If it
* is FALSE, the search begins after @ctx->attr.
*
* If @ic is IGNORE_CASE, the @name comparisson is not case sensitive and
* @ctx->ntfs_ino must be set to the ntfs inode to which the mft record
- * @ctx->mrec belongs. This is so we can get at the ntfs volume and hence at
- * the upcase table. If @ic is CASE_SENSITIVE, the comparison is case
- * sensitive. When @name is present, @name_len is the @name length in Unicode
+ * @ctx->mrec belongs. This is so we can get at the ntfs volume and hence at
+ * the upcase table. If @ic is CASE_SENSITIVE, the comparison is case
+ * sensitive. When @name is present, @name_len is the @name length in Unicode
* characters.
*
* If @name is not present (NULL), we assume that the unnamed attribute is
* being searched for.
*
- * Finally, the resident attribute value @val is looked for, if present. If @val
- * is not present (NULL), @val_len is ignored.
+ * Finally, the resident attribute value @val is looked for, if present. If
+ * @val is not present (NULL), @val_len is ignored.
*
- * find_attr() only searches the specified mft record and it ignores the
+ * ntfs_attr_find() only searches the specified mft record and it ignores the
* presence of an attribute list attribute (unless it is the one being searched
- * for, obviously). If you need to take attribute lists into consideration, use
- * lookup_attr() instead (see below). This also means that you cannot use
- * find_attr() to search for extent records of non-resident attributes, as
- * extents with lowest_vcn != 0 are usually described by the attribute list
- * attribute only. - Note that it is possible that the first extent is only in
- * the attribute list while the last extent is in the base mft record, so don't
- * rely on being able to find the first extent in the base mft record.
+ * for, obviously). If you need to take attribute lists into consideration,
+ * use ntfs_attr_lookup() instead (see below). This also means that you cannot
+ * use ntfs_attr_find() to search for extent records of non-resident
+ * attributes, as extents with lowest_vcn != 0 are usually described by the
+ * attribute list attribute only. - Note that it is possible that the first
+ * extent is only in the attribute list while the last extent is in the base
+ * mft record, so do not rely on being able to find the first extent in the
+ * base mft record.
*
* Warning: Never use @val when looking for attribute types which can be
* non-resident as this most likely will result in a crash!
*/
-BOOL find_attr(const ATTR_TYPES type, const uchar_t *name, const u32 name_len,
- const IGNORE_CASE_BOOL ic, const u8 *val, const u32 val_len,
- attr_search_context *ctx)
+static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name,
+ const u32 name_len, const IGNORE_CASE_BOOL ic,
+ const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx)
{
ATTR_RECORD *a;
- ntfs_volume *vol;
- uchar_t *upcase;
- u32 upcase_len;
+ ntfs_volume *vol = ctx->ntfs_ino->vol;
+ ntfschar *upcase = vol->upcase;
+ u32 upcase_len = vol->upcase_len;
- if (ic == IGNORE_CASE) {
- vol = ctx->ntfs_ino->vol;
- upcase = vol->upcase;
- upcase_len = vol->upcase_len;
- } else {
- vol = NULL;
- upcase = NULL;
- upcase_len = 0;
- }
/*
* Iterate over attributes in mft record starting at @ctx->attr, or the
* attribute following that, if @ctx->is_first is TRUE.
le32_to_cpu(ctx->mrec->bytes_allocated))
break;
ctx->attr = a;
- /* We catch $END with this more general check, too... */
- if (le32_to_cpu(a->type) > le32_to_cpu(type))
- return FALSE;
+ if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) ||
+ a->type == AT_END))
+ return -ENOENT;
if (unlikely(!a->length))
break;
if (a->type != type)
continue;
/*
- * If @name is present, compare the two names. If @name is
+ * If @name is present, compare the two names. If @name is
* missing, assume we want an unnamed attribute.
*/
if (!name) {
/* The search failed if the found attribute is named. */
if (a->name_length)
- return FALSE;
+ return -ENOENT;
} else if (!ntfs_are_names_equal(name, name_len,
- (uchar_t*)((u8*)a + le16_to_cpu(a->name_offset)),
+ (ntfschar*)((u8*)a + le16_to_cpu(a->name_offset)),
a->name_length, ic, upcase, upcase_len)) {
register int rc;
-
+
rc = ntfs_collate_names(name, name_len,
- (uchar_t*)((u8*)a +
- le16_to_cpu(a->name_offset)),
+ (ntfschar*)((u8*)a +
+ le16_to_cpu(a->name_offset)),
a->name_length, 1, IGNORE_CASE,
upcase, upcase_len);
/*
* matching attribute.
*/
if (rc == -1)
- return FALSE;
+ return -ENOENT;
/* If the strings are not equal, continue search. */
if (rc)
- continue;
+ continue;
rc = ntfs_collate_names(name, name_len,
- (uchar_t*)((u8*)a +
- le16_to_cpu(a->name_offset)),
+ (ntfschar*)((u8*)a +
+ le16_to_cpu(a->name_offset)),
a->name_length, 1, CASE_SENSITIVE,
upcase, upcase_len);
if (rc == -1)
- return FALSE;
+ return -ENOENT;
if (rc)
continue;
}
/*
* The names match or @name not present and attribute is
- * unnamed. If no @val specified, we have found the attribute
+ * unnamed. If no @val specified, we have found the attribute
* and are done.
*/
if (!val)
- return TRUE;
+ return 0;
/* @val is present; compare values. */
else {
- u32 vl;
register int rc;
- vl = le32_to_cpu(a->data.resident.value_length);
- if (vl > val_len)
- vl = val_len;
-
rc = memcmp(val, (u8*)a + le16_to_cpu(
- a->data.resident.value_offset), vl);
+ a->data.resident.value_offset),
+ min_t(u32, val_len, le32_to_cpu(
+ a->data.resident.value_length)));
/*
* If @val collates before the current attribute's
* value, there is no matching attribute.
*/
if (!rc) {
register u32 avl;
+
avl = le32_to_cpu(
a->data.resident.value_length);
if (val_len == avl)
- return TRUE;
+ return 0;
if (val_len < avl)
- return FALSE;
+ return -ENOENT;
} else if (rc < 0)
- return FALSE;
+ return -ENOENT;
}
}
- ntfs_error(NULL, "Inode is corrupt. Run chkdsk.");
- return FALSE;
+ ntfs_error(vol->sb, "Inode is corrupt. Run chkdsk.");
+ NVolSetErrors(vol);
+ return -EIO;
}
/**
* load_attribute_list - load an attribute list into memory
* @vol: ntfs volume from which to read
- * @run_list: run list of the attribute list
+ * @runlist: runlist of the attribute list
* @al_start: destination buffer
* @size: size of the destination buffer in bytes
* @initialized_size: initialized size of the attribute list
*
- * Walk the run list @run_list and load all clusters from it copying them into
+ * Walk the runlist @runlist and load all clusters from it copying them into
* the linear buffer @al. The maximum number of bytes copied to @al is @size
* bytes. Note, @size does not need to be a multiple of the cluster size. If
* @initialized_size is less than @size, the region in @al between
*
* Return 0 on success or -errno on error.
*/
-int load_attribute_list(ntfs_volume *vol, run_list *run_list, u8 *al_start,
+int load_attribute_list(ntfs_volume *vol, runlist *runlist, u8 *al_start,
const s64 size, const s64 initialized_size)
{
LCN lcn;
u8 *al = al_start;
u8 *al_end = al + initialized_size;
- run_list_element *rl;
+ runlist_element *rl;
struct buffer_head *bh;
struct super_block *sb;
unsigned long block_size;
unsigned char block_size_bits;
ntfs_debug("Entering.");
- if (!vol || !run_list || !al || size <= 0 || initialized_size < 0 ||
+ if (!vol || !runlist || !al || size <= 0 || initialized_size < 0 ||
initialized_size > size)
return -EINVAL;
if (!initialized_size) {
sb = vol->sb;
block_size = sb->s_blocksize;
block_size_bits = sb->s_blocksize_bits;
- down_read(&run_list->lock);
- rl = run_list->rl;
- /* Read all clusters specified by the run list one run at a time. */
+ down_read(&runlist->lock);
+ rl = runlist->rl;
+ /* Read all clusters specified by the runlist one run at a time. */
while (rl->length) {
- lcn = vcn_to_lcn(rl, rl->vcn);
+ lcn = ntfs_rl_vcn_to_lcn(rl, rl->vcn);
ntfs_debug("Reading vcn = 0x%llx, lcn = 0x%llx.",
(unsigned long long)rl->vcn,
(unsigned long long)lcn);
/* The attribute list cannot be sparse. */
if (lcn < 0) {
- ntfs_error(sb, "vcn_to_lcn() failed. Cannot read "
- "attribute list.");
+ ntfs_error(sb, "ntfs_rl_vcn_to_lcn() failed. Cannot "
+ "read attribute list.");
goto err_out;
}
block = lcn << vol->cluster_size_bits >> block_size_bits;
memset(al_start + initialized_size, 0, size - initialized_size);
}
done:
- up_read(&run_list->lock);
+ up_read(&runlist->lock);
return err;
do_final:
if (al < al_end) {
}
/**
- * find_external_attr - find an attribute in the attribute list of an ntfs inode
+ * ntfs_external_attr_find - find an attribute in the attribute list of an inode
* @type: attribute type to find
* @name: attribute name to find (optional, i.e. NULL means don't care)
* @name_len: attribute name length (only needed if @name present)
* @val_len: attribute value length
* @ctx: search context with mft record and attribute to search from
*
- * You shouldn't need to call this function directly. Use lookup_attr() instead.
+ * You should not need to call this function directly. Use ntfs_attr_lookup()
+ * instead.
*
* Find an attribute by searching the attribute list for the corresponding
- * attribute list entry. Having found the entry, map the mft record for read
- * if the attribute is in a different mft record/inode, find_attr the attribute
+ * attribute list entry. Having found the entry, map the mft record if the
+ * attribute is in a different mft record/inode, ntfs_attr_find() the attribute
* in there and return it.
*
* On first search @ctx->ntfs_ino must be the base mft record and @ctx must
- * have been obtained from a call to get_attr_search_ctx(). On subsequent calls
- * @ctx->ntfs_ino can be any extent inode, too (@ctx->base_ntfs_ino is then the
- * base inode).
+ * have been obtained from a call to ntfs_attr_get_search_ctx(). On subsequent
+ * calls @ctx->ntfs_ino can be any extent inode, too (@ctx->base_ntfs_ino is
+ * then the base inode).
*
* After finishing with the attribute/mft record you need to call
- * release_attr_search_ctx() to cleanup the search context (unmapping any
+ * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
* mapped inodes, etc).
*
- * Return TRUE if the search was successful and FALSE if not. When TRUE,
- * @ctx->attr is the found attribute and it is in mft record @ctx->mrec. When
- * FALSE, @ctx->attr is the attribute which collates just after the attribute
- * being searched for in the base ntfs inode, i.e. if one wants to add the
- * attribute to the mft record this is the correct place to insert it into
- * and if there is not enough space, the attribute should be placed in an
- * extent mft record.
+ * If the attribute is found, ntfs_external_attr_find() returns 0 and
+ * @ctx->attr will point to the found attribute. @ctx->mrec will point to the
+ * mft record in which @ctx->attr is located and @ctx->al_entry will point to
+ * the attribute list entry for the attribute.
+ *
+ * If the attribute is not found, ntfs_external_attr_find() returns -ENOENT and
+ * @ctx->attr will point to the attribute in the base mft record before which
+ * the attribute being searched for would need to be inserted if such an action
+ * were to be desired. @ctx->mrec will point to the mft record in which
+ * @ctx->attr is located and @ctx->al_entry will point to the attribute list
+ * entry of the attribute before which the attribute being searched for would
+ * need to be inserted if such an action were to be desired.
+ *
+ * Thus to insert the not found attribute, one wants to add the attribute to
+ * @ctx->mrec (the base mft record) and if there is not enough space, the
+ * attribute should be placed in a newly allocated extent mft record. The
+ * attribute list entry for the inserted attribute should be inserted in the
+ * attribute list attribute at @ctx->al_entry.
+ *
+ * On actual error, ntfs_external_attr_find() returns -EIO. In this case
+ * @ctx->attr is undefined and in particular do not rely on it not changing.
*/
-static BOOL find_external_attr(const ATTR_TYPES type, const uchar_t *name,
- const u32 name_len, const IGNORE_CASE_BOOL ic,
- const VCN lowest_vcn, const u8 *val, const u32 val_len,
- attr_search_context *ctx)
+static int ntfs_external_attr_find(const ATTR_TYPE type,
+ const ntfschar *name, const u32 name_len,
+ const IGNORE_CASE_BOOL ic, const VCN lowest_vcn,
+ const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx)
{
ntfs_inode *base_ni, *ni;
ntfs_volume *vol;
ATTR_LIST_ENTRY *al_entry, *next_al_entry;
u8 *al_start, *al_end;
ATTR_RECORD *a;
- uchar_t *al_name;
+ ntfschar *al_name;
u32 al_name_len;
+ int err = 0;
+ static const char *es = " Unmount and run chkdsk.";
ni = ctx->ntfs_ino;
base_ni = ctx->base_ntfs_ino;
}
if (ni == base_ni)
ctx->base_attr = ctx->attr;
+ if (type == AT_END)
+ goto not_found;
vol = base_ni->vol;
al_start = base_ni->attr_list;
al_end = al_start + base_ni->attr_list_size;
if (type != al_entry->type)
continue;
/*
- * If @name is present, compare the two names. If @name is
+ * If @name is present, compare the two names. If @name is
* missing, assume we want an unnamed attribute.
*/
al_name_len = al_entry->name_length;
- al_name = (uchar_t*)((u8*)al_entry + al_entry->name_offset);
+ al_name = (ntfschar*)((u8*)al_entry + al_entry->name_offset);
if (!name) {
if (al_name_len)
goto not_found;
continue;
/*
* FIXME: Reverse engineering showed 0, IGNORE_CASE but
- * that is inconsistent with find_attr(). The subsequent
- * rc checks were also different. Perhaps I made a
- * mistake in one of the two. Need to recheck which is
- * correct or at least see what is going on... (AIA)
+ * that is inconsistent with ntfs_attr_find(). The
+ * subsequent rc checks were also different. Perhaps I
+ * made a mistake in one of the two. Need to recheck
+ * which is correct or at least see what is going on...
+ * (AIA)
*/
rc = ntfs_collate_names(name, name_len, al_name,
al_name_len, 1, CASE_SENSITIVE,
}
/*
* The names match or @name not present and attribute is
- * unnamed. Now check @lowest_vcn. Continue search if the
- * next attribute list entry still fits @lowest_vcn. Otherwise
+ * unnamed. Now check @lowest_vcn. Continue search if the
+ * next attribute list entry still fits @lowest_vcn. Otherwise
* we have reached the right one or the search has failed.
*/
if (lowest_vcn && (u8*)next_al_entry >= al_start &&
(u8*)next_al_entry + 6 < al_end &&
(u8*)next_al_entry + le16_to_cpu(
- next_al_entry->length) <= al_end &&
+ next_al_entry->length) <= al_end &&
sle64_to_cpu(next_al_entry->lowest_vcn) <=
- sle64_to_cpu(lowest_vcn) &&
+ lowest_vcn &&
next_al_entry->type == al_entry->type &&
next_al_entry->name_length == al_name_len &&
- ntfs_are_names_equal((uchar_t*)((u8*)
+ ntfs_are_names_equal((ntfschar*)((u8*)
next_al_entry +
next_al_entry->name_offset),
next_al_entry->name_length,
if (MREF_LE(al_entry->mft_reference) == ni->mft_no) {
if (MSEQNO_LE(al_entry->mft_reference) != ni->seq_no) {
ntfs_error(vol->sb, "Found stale mft "
- "reference in attribute list!");
+ "reference in attribute list "
+ "of base inode 0x%lx.%s",
+ base_ni->mft_no, es);
+ err = -EIO;
break;
}
} else { /* Mft references do not match. */
} else {
/* We want an extent record. */
ctx->mrec = map_extent_mft_record(base_ni,
- al_entry->mft_reference, &ni);
- ctx->ntfs_ino = ni;
+ le64_to_cpu(
+ al_entry->mft_reference), &ni);
if (IS_ERR(ctx->mrec)) {
- ntfs_error(vol->sb, "Failed to map mft "
- "record, error code "
- "%ld.",
- -PTR_ERR(ctx->mrec));
+ ntfs_error(vol->sb, "Failed to map "
+ "extent mft record "
+ "0x%lx of base inode "
+ "0x%lx.%s",
+ MREF_LE(al_entry->
+ mft_reference),
+ base_ni->mft_no, es);
+ err = PTR_ERR(ctx->mrec);
+ if (err == -ENOENT)
+ err = -EIO;
+ /* Cause @ctx to be sanitized below. */
+ ni = NULL;
break;
}
+ ctx->ntfs_ino = ni;
}
ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
le16_to_cpu(ctx->mrec->attrs_offset));
* current al_entry.
*/
/*
- * We could call into find_attr() to find the right attribute
- * in this mft record but this would be less efficient and not
- * quite accurate as find_attr() ignores the attribute instance
- * numbers for example which become important when one plays
- * with attribute lists. Also, because a proper match has been
- * found in the attribute list entry above, the comparison can
- * now be optimized. So it is worth re-implementing a
- * simplified find_attr() here.
+ * We could call into ntfs_attr_find() to find the right
+ * attribute in this mft record but this would be less
+ * efficient and not quite accurate as ntfs_attr_find() ignores
+ * the attribute instance numbers for example which become
+ * important when one plays with attribute lists. Also,
+ * because a proper match has been found in the attribute list
+ * entry above, the comparison can now be optimized. So it is
+ * worth re-implementing a simplified ntfs_attr_find() here.
*/
a = ctx->attr;
/*
break;
if (al_entry->instance != a->instance)
goto do_next_attr;
+ /*
+ * If the type and/or the name are mismatched between the
+ * attribute list entry and the attribute record, there is
+ * corruption so we break and return error EIO.
+ */
if (al_entry->type != a->type)
- continue;
- if (name) {
- if (a->name_length != al_name_len)
- continue;
- if (!ntfs_are_names_equal((uchar_t*)((u8*)a +
- le16_to_cpu(a->name_offset)),
- a->name_length, al_name, al_name_len,
- CASE_SENSITIVE, vol->upcase,
- vol->upcase_len))
- continue;
- }
+ break;
+ if (!ntfs_are_names_equal((ntfschar*)((u8*)a +
+ le16_to_cpu(a->name_offset)), a->name_length,
+ al_name, al_name_len, CASE_SENSITIVE,
+ vol->upcase, vol->upcase_len))
+ break;
ctx->attr = a;
/*
* If no @val specified or @val specified and it matches, we
le16_to_cpu(a->data.resident.value_offset),
val, val_len))) {
ntfs_debug("Done, found.");
- return TRUE;
+ return 0;
}
do_next_attr:
/* Proceed to the next attribute in the current mft record. */
a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length));
goto do_next_attr_loop;
}
- ntfs_error(base_ni->vol->sb, "Inode contains corrupt attribute list "
- "attribute.\n");
+ if (!err) {
+ ntfs_error(vol->sb, "Base inode 0x%lx contains corrupt "
+ "attribute list attribute.%s", base_ni->mft_no,
+ es);
+ err = -EIO;
+ }
if (ni != base_ni) {
- unmap_extent_mft_record(ni);
+ if (ni)
+ unmap_extent_mft_record(ni);
ctx->ntfs_ino = base_ni;
ctx->mrec = ctx->base_mrec;
ctx->attr = ctx->base_attr;
}
+ if (err != -ENOMEM)
+ NVolSetErrors(vol);
+ return err;
+not_found:
/*
- * FIXME: We absolutely have to return ERROR status instead of just
- * false or we will blow up or even worse cause corruption when we add
- * write support and we reach this code path!
+ * If we were looking for AT_END, we reset the search context @ctx and
+ * use ntfs_attr_find() to seek to the end of the base mft record.
*/
- printk(KERN_CRIT "NTFS: FIXME: Hit unfinished error code path!!!\n");
- return FALSE;
-not_found:
+ if (type == AT_END) {
+ ntfs_attr_reinit_search_ctx(ctx);
+ return ntfs_attr_find(AT_END, name, name_len, ic, val, val_len,
+ ctx);
+ }
+ /*
+ * The attribute was not found. Before we return, we want to ensure
+ * @ctx->mrec and @ctx->attr indicate the position at which the
+ * attribute should be inserted in the base mft record. Since we also
+ * want to preserve @ctx->al_entry we cannot reinitialize the search
+ * context using ntfs_attr_reinit_search_ctx() as this would set
+ * @ctx->al_entry to NULL. Thus we do the necessary bits manually (see
+ * ntfs_attr_init_search_ctx() below). Note, we _only_ preserve
+ * @ctx->al_entry as the remaining fields (base_*) are identical to
+ * their non base_ counterparts and we cannot set @ctx->base_attr
+ * correctly yet as we do not know what @ctx->attr will be set to by
+ * the call to ntfs_attr_find() below.
+ */
+ if (ni != base_ni)
+ unmap_extent_mft_record(ni);
+ ctx->mrec = ctx->base_mrec;
+ ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
+ le16_to_cpu(ctx->mrec->attrs_offset));
+ ctx->is_first = TRUE;
+ ctx->ntfs_ino = base_ni;
+ ctx->base_ntfs_ino = NULL;
+ ctx->base_mrec = NULL;
+ ctx->base_attr = NULL;
/*
- * Seek to the end of the base mft record, i.e. when we return false,
- * ctx->mrec and ctx->attr indicate where the attribute should be
- * inserted into the attribute record.
- * And of course ctx->al_entry points to the end of the attribute
- * list inside NTFS_I(ctx->base_vfs_ino)->attr_list.
- *
- * FIXME: Do we really want to do this here? Think about it... (AIA)
+ * In case there are multiple matches in the base mft record, need to
+ * keep enumerating until we get an attribute not found response (or
+ * another error), otherwise we would keep returning the same attribute
+ * over and over again and all programs using us for enumeration would
+ * lock up in a tight loop.
*/
- reinit_attr_search_ctx(ctx);
- find_attr(type, name, name_len, ic, val, val_len, ctx);
+ do {
+ err = ntfs_attr_find(type, name, name_len, ic, val, val_len,
+ ctx);
+ } while (!err);
ntfs_debug("Done, not found.");
- return FALSE;
+ return err;
}
/**
- * lookup_attr - find an attribute in an ntfs inode
+ * ntfs_attr_lookup - find an attribute in an ntfs inode
* @type: attribute type to find
* @name: attribute name to find (optional, i.e. NULL means don't care)
* @name_len: attribute name length (only needed if @name present)
* @val_len: attribute value length
* @ctx: search context with mft record and attribute to search from
*
- * Find an attribute in an ntfs inode. On first search @ctx->ntfs_ino must
+ * Find an attribute in an ntfs inode. On first search @ctx->ntfs_ino must
* be the base mft record and @ctx must have been obtained from a call to
- * get_attr_search_ctx().
+ * ntfs_attr_get_search_ctx().
*
* This function transparently handles attribute lists and @ctx is used to
* continue searches where they were left off at.
*
* After finishing with the attribute/mft record you need to call
- * release_attr_search_ctx() to cleanup the search context (unmapping any
+ * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
* mapped inodes, etc).
*
- * Return TRUE if the search was successful and FALSE if not. When TRUE,
- * @ctx->attr is the found attribute and it is in mft record @ctx->mrec. When
- * FALSE, @ctx->attr is the attribute which collates just after the attribute
- * being searched for, i.e. if one wants to add the attribute to the mft
- * record this is the correct place to insert it into.
+ * Return 0 if the search was successful and -errno if not.
+ *
+ * When 0, @ctx->attr is the found attribute and it is in mft record
+ * @ctx->mrec. If an attribute list attribute is present, @ctx->al_entry is
+ * the attribute list entry of the found attribute.
+ *
+ * When -ENOENT, @ctx->attr is the attribute which collates just after the
+ * attribute being searched for, i.e. if one wants to add the attribute to the
+ * mft record this is the correct place to insert it into. If an attribute
+ * list attribute is present, @ctx->al_entry is the attribute list entry which
+ * collates just after the attribute list entry of the attribute being searched
+ * for, i.e. if one wants to add the attribute to the mft record this is the
+ * correct place to insert its attribute list entry into.
+ *
+ * When -errno != -ENOENT, an error occured during the lookup. @ctx->attr is
+ * then undefined and in particular you should not rely on it not changing.
*/
-BOOL lookup_attr(const ATTR_TYPES type, const uchar_t *name, const u32 name_len,
- const IGNORE_CASE_BOOL ic, const VCN lowest_vcn, const u8 *val,
- const u32 val_len, attr_search_context *ctx)
+int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name,
+ const u32 name_len, const IGNORE_CASE_BOOL ic,
+ const VCN lowest_vcn, const u8 *val, const u32 val_len,
+ ntfs_attr_search_ctx *ctx)
{
ntfs_inode *base_ni;
base_ni = ctx->ntfs_ino;
/* Sanity check, just for debugging really. */
BUG_ON(!base_ni);
- if (!NInoAttrList(base_ni))
- return find_attr(type, name, name_len, ic, val, val_len, ctx);
- return find_external_attr(type, name, name_len, ic, lowest_vcn, val,
- val_len, ctx);
+ if (!NInoAttrList(base_ni) || type == AT_ATTRIBUTE_LIST)
+ return ntfs_attr_find(type, name, name_len, ic, val, val_len,
+ ctx);
+ return ntfs_external_attr_find(type, name, name_len, ic, lowest_vcn,
+ val, val_len, ctx);
}
/**
- * init_attr_search_ctx - initialize an attribute search context
+ * ntfs_attr_init_search_ctx - initialize an attribute search context
* @ctx: attribute search context to initialize
* @ni: ntfs inode with which to initialize the search context
* @mrec: mft record with which to initialize the search context
*
* Initialize the attribute search context @ctx with @ni and @mrec.
*/
-static inline void init_attr_search_ctx(attr_search_context *ctx,
+static inline void ntfs_attr_init_search_ctx(ntfs_attr_search_ctx *ctx,
ntfs_inode *ni, MFT_RECORD *mrec)
{
ctx->mrec = mrec;
}
/**
- * reinit_attr_search_ctx - reinitialize an attribute search context
+ * ntfs_attr_reinit_search_ctx - reinitialize an attribute search context
* @ctx: attribute search context to reinitialize
*
* Reinitialize the attribute search context @ctx, unmapping an associated
* This is used when a search for a new attribute is being started to reset
* the search context to the beginning.
*/
-void reinit_attr_search_ctx(attr_search_context *ctx)
+void ntfs_attr_reinit_search_ctx(ntfs_attr_search_ctx *ctx)
{
if (likely(!ctx->base_ntfs_ino)) {
/* No attribute list. */
/* Sanity checks are performed elsewhere. */
ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
le16_to_cpu(ctx->mrec->attrs_offset));
+ /*
+ * This needs resetting due to ntfs_external_attr_find() which
+ * can leave it set despite having zeroed ctx->base_ntfs_ino.
+ */
+ ctx->al_entry = NULL;
return;
} /* Attribute list. */
if (ctx->ntfs_ino != ctx->base_ntfs_ino)
unmap_extent_mft_record(ctx->ntfs_ino);
- init_attr_search_ctx(ctx, ctx->base_ntfs_ino, ctx->base_mrec);
+ ntfs_attr_init_search_ctx(ctx, ctx->base_ntfs_ino, ctx->base_mrec);
return;
}
/**
- * get_attr_search_ctx - allocate and initialize a new attribute search context
+ * ntfs_attr_get_search_ctx - allocate/initialize a new attribute search context
* @ni: ntfs inode with which to initialize the search context
* @mrec: mft record with which to initialize the search context
*
* Allocate a new attribute search context, initialize it with @ni and @mrec,
* and return it. Return NULL if allocation failed.
*/
-attr_search_context *get_attr_search_ctx(ntfs_inode *ni, MFT_RECORD *mrec)
+ntfs_attr_search_ctx *ntfs_attr_get_search_ctx(ntfs_inode *ni, MFT_RECORD *mrec)
{
- attr_search_context *ctx;
+ ntfs_attr_search_ctx *ctx;
ctx = kmem_cache_alloc(ntfs_attr_ctx_cache, SLAB_NOFS);
if (ctx)
- init_attr_search_ctx(ctx, ni, mrec);
+ ntfs_attr_init_search_ctx(ctx, ni, mrec);
return ctx;
}
/**
- * put_attr_search_ctx - release an attribute search context
+ * ntfs_attr_put_search_ctx - release an attribute search context
* @ctx: attribute search context to free
*
* Release the attribute search context @ctx, unmapping an associated extent
* mft record if present.
*/
-void put_attr_search_ctx(attr_search_context *ctx)
+void ntfs_attr_put_search_ctx(ntfs_attr_search_ctx *ctx)
{
if (ctx->base_ntfs_ino && ctx->ntfs_ino != ctx->base_ntfs_ino)
unmap_extent_mft_record(ctx->ntfs_ino);
return;
}
+/**
+ * ntfs_attr_find_in_attrdef - find an attribute in the $AttrDef system file
+ * @vol: ntfs volume to which the attribute belongs
+ * @type: attribute type which to find
+ *
+ * Search for the attribute definition record corresponding to the attribute
+ * @type in the $AttrDef system file.
+ *
+ * Return the attribute type definition record if found and NULL if not found.
+ */
+static ATTR_DEF *ntfs_attr_find_in_attrdef(const ntfs_volume *vol,
+ const ATTR_TYPE type)
+{
+ ATTR_DEF *ad;
+
+ BUG_ON(!vol->attrdef);
+ BUG_ON(!type);
+ for (ad = vol->attrdef; (u8*)ad - (u8*)vol->attrdef <
+ vol->attrdef_size && ad->type; ++ad) {
+ /* We have not found it yet, carry on searching. */
+ if (likely(le32_to_cpu(ad->type) < le32_to_cpu(type)))
+ continue;
+ /* We found the attribute; return it. */
+ if (likely(ad->type == type))
+ return ad;
+ /* We have gone too far already. No point in continuing. */
+ break;
+ }
+ /* Attribute not found. */
+ ntfs_debug("Attribute type 0x%x not found in $AttrDef.",
+ le32_to_cpu(type));
+ return NULL;
+}
+
+/**
+ * ntfs_attr_size_bounds_check - check a size of an attribute type for validity
+ * @vol: ntfs volume to which the attribute belongs
+ * @type: attribute type which to check
+ * @size: size which to check
+ *
+ * Check whether the @size in bytes is valid for an attribute of @type on the
+ * ntfs volume @vol. This information is obtained from $AttrDef system file.
+ *
+ * Return 0 if valid, -ERANGE if not valid, or -ENOENT if the attribute is not
+ * listed in $AttrDef.
+ */
+int ntfs_attr_size_bounds_check(const ntfs_volume *vol, const ATTR_TYPE type,
+ const s64 size)
+{
+ ATTR_DEF *ad;
+
+ BUG_ON(size < 0);
+ /*
+ * $ATTRIBUTE_LIST has a maximum size of 256kiB, but this is not
+ * listed in $AttrDef.
+ */
+ if (unlikely(type == AT_ATTRIBUTE_LIST && size > 256 * 1024))
+ return -ERANGE;
+ /* Get the $AttrDef entry for the attribute @type. */
+ ad = ntfs_attr_find_in_attrdef(vol, type);
+ if (unlikely(!ad))
+ return -ENOENT;
+ /* Do the bounds check. */
+ if (((sle64_to_cpu(ad->min_size) > 0) &&
+ size < sle64_to_cpu(ad->min_size)) ||
+ ((sle64_to_cpu(ad->max_size) > 0) && size >
+ sle64_to_cpu(ad->max_size)))
+ return -ERANGE;
+ return 0;
+}
+
+/**
+ * ntfs_attr_can_be_non_resident - check if an attribute can be non-resident
+ * @vol: ntfs volume to which the attribute belongs
+ * @type: attribute type which to check
+ *
+ * Check whether the attribute of @type on the ntfs volume @vol is allowed to
+ * be non-resident. This information is obtained from $AttrDef system file.
+ *
+ * Return 0 if the attribute is allowed to be non-resident, -EPERM if not, or
+ * -ENOENT if the attribute is not listed in $AttrDef.
+ */
+int ntfs_attr_can_be_non_resident(const ntfs_volume *vol, const ATTR_TYPE type)
+{
+ ATTR_DEF *ad;
+
+ /*
+ * $DATA is always allowed to be non-resident even if $AttrDef does not
+ * specify this in the flags of the $DATA attribute definition record.
+ */
+ if (type == AT_DATA)
+ return 0;
+ /* Find the attribute definition record in $AttrDef. */
+ ad = ntfs_attr_find_in_attrdef(vol, type);
+ if (unlikely(!ad))
+ return -ENOENT;
+ /* Check the flags and return the result. */
+ if (ad->flags & CAN_BE_NON_RESIDENT)
+ return 0;
+ return -EPERM;
+}
+
+/**
+ * ntfs_attr_can_be_resident - check if an attribute can be resident
+ * @vol: ntfs volume to which the attribute belongs
+ * @type: attribute type which to check
+ *
+ * Check whether the attribute of @type on the ntfs volume @vol is allowed to
+ * be resident. This information is derived from our ntfs knowledge and may
+ * not be completely accurate, especially when user defined attributes are
+ * present. Basically we allow everything to be resident except for index
+ * allocation and $EA attributes.
+ *
+ * Return 0 if the attribute is allowed to be non-resident and -EPERM if not.
+ *
+ * Warning: In the system file $MFT the attribute $Bitmap must be non-resident
+ * otherwise windows will not boot (blue screen of death)! We cannot
+ * check for this here as we do not know which inode's $Bitmap is
+ * being asked about so the caller needs to special case this.
+ */
+int ntfs_attr_can_be_resident(const ntfs_volume *vol, const ATTR_TYPE type)
+{
+ if (type != AT_INDEX_ALLOCATION && type != AT_EA)
+ return 0;
+ return -EPERM;
+}
+
+/**
+ * ntfs_attr_record_resize - resize an attribute record
+ * @m: mft record containing attribute record
+ * @a: attribute record to resize
+ * @new_size: new size in bytes to which to resize the attribute record @a
+ *
+ * Resize the attribute record @a, i.e. the resident part of the attribute, in
+ * the mft record @m to @new_size bytes.
+ *
+ * Return 0 on success and -errno on error. The following error codes are
+ * defined:
+ * -ENOSPC - Not enough space in the mft record @m to perform the resize.
+ *
+ * Note: On error, no modifications have been performed whatsoever.
+ *
+ * Warning: If you make a record smaller without having copied all the data you
+ * are interested in the data may be overwritten.
+ */
+int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size)
+{
+ ntfs_debug("Entering for new_size %u.", new_size);
+ /* Align to 8 bytes if it is not already done. */
+ if (new_size & 7)
+ new_size = (new_size + 7) & ~7;
+ /* If the actual attribute length has changed, move things around. */
+ if (new_size != le32_to_cpu(a->length)) {
+ u32 new_muse = le32_to_cpu(m->bytes_in_use) -
+ le32_to_cpu(a->length) + new_size;
+ /* Not enough space in this mft record. */
+ if (new_muse > le32_to_cpu(m->bytes_allocated))
+ return -ENOSPC;
+ /* Move attributes following @a to their new location. */
+ memmove((u8*)a + new_size, (u8*)a + le32_to_cpu(a->length),
+ le32_to_cpu(m->bytes_in_use) - ((u8*)a -
+ (u8*)m) - le32_to_cpu(a->length));
+ /* Adjust @m to reflect the change in used space. */
+ m->bytes_in_use = cpu_to_le32(new_muse);
+ /* Adjust @a to reflect the new size. */
+ if (new_size >= offsetof(ATTR_REC, length) + sizeof(a->length))
+ a->length = cpu_to_le32(new_size);
+ }
+ return 0;
+}
+
+/**
+ * ntfs_attr_set - fill (a part of) an attribute with a byte
+ * @ni: ntfs inode describing the attribute to fill
+ * @ofs: offset inside the attribute at which to start to fill
+ * @cnt: number of bytes to fill
+ * @val: the unsigned 8-bit value with which to fill the attribute
+ *
+ * Fill @cnt bytes of the attribute described by the ntfs inode @ni starting at
+ * byte offset @ofs inside the attribute with the constant byte @val.
+ *
+ * This function is effectively like memset() applied to an ntfs attribute.
+ *
+ * Return 0 on success and -errno on error. An error code of -ESPIPE means
+ * that @ofs + @cnt were outside the end of the attribute and no write was
+ * performed.
+ */
+int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
+{
+ ntfs_volume *vol = ni->vol;
+ struct address_space *mapping;
+ struct page *page;
+ u8 *kaddr;
+ pgoff_t idx, end;
+ unsigned int start_ofs, end_ofs, size;
+
+ ntfs_debug("Entering for ofs 0x%llx, cnt 0x%llx, val 0x%hx.",
+ (long long)ofs, (long long)cnt, val);
+ BUG_ON(ofs < 0);
+ BUG_ON(cnt < 0);
+ if (!cnt)
+ goto done;
+ mapping = VFS_I(ni)->i_mapping;
+ /* Work out the starting index and page offset. */
+ idx = ofs >> PAGE_CACHE_SHIFT;
+ start_ofs = ofs & ~PAGE_CACHE_MASK;
+ /* Work out the ending index and page offset. */
+ end = ofs + cnt;
+ end_ofs = end & ~PAGE_CACHE_MASK;
+ /* If the end is outside the inode size return -ESPIPE. */
+ if (unlikely(end > VFS_I(ni)->i_size)) {
+ ntfs_error(vol->sb, "Request exceeds end of attribute.");
+ return -ESPIPE;
+ }
+ end >>= PAGE_CACHE_SHIFT;
+ /* If there is a first partial page, need to do it the slow way. */
+ if (start_ofs) {
+ page = read_cache_page(mapping, idx,
+ (filler_t*)mapping->a_ops->readpage, NULL);
+ if (IS_ERR(page)) {
+ ntfs_error(vol->sb, "Failed to read first partial "
+ "page (sync error, index 0x%lx).", idx);
+ return PTR_ERR(page);
+ }
+ wait_on_page_locked(page);
+ if (unlikely(!PageUptodate(page))) {
+ ntfs_error(vol->sb, "Failed to read first partial page "
+ "(async error, index 0x%lx).", idx);
+ page_cache_release(page);
+ return PTR_ERR(page);
+ }
+ /*
+ * If the last page is the same as the first page, need to
+ * limit the write to the end offset.
+ */
+ size = PAGE_CACHE_SIZE;
+ if (idx == end)
+ size = end_ofs;
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + start_ofs, val, size - start_ofs);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ set_page_dirty(page);
+ page_cache_release(page);
+ if (idx == end)
+ goto done;
+ idx++;
+ }
+ /* Do the whole pages the fast way. */
+ for (; idx < end; idx++) {
+ /* Find or create the current page. (The page is locked.) */
+ page = grab_cache_page(mapping, idx);
+ if (unlikely(!page)) {
+ ntfs_error(vol->sb, "Insufficient memory to grab "
+ "page (index 0x%lx).", idx);
+ return -ENOMEM;
+ }
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr, val, PAGE_CACHE_SIZE);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ /*
+ * If the page has buffers, mark them uptodate since buffer
+ * state and not page state is definitive in 2.6 kernels.
+ */
+ if (page_has_buffers(page)) {
+ struct buffer_head *bh, *head;
+
+ bh = head = page_buffers(page);
+ do {
+ set_buffer_uptodate(bh);
+ } while ((bh = bh->b_this_page) != head);
+ }
+ /* Now that buffers are uptodate, set the page uptodate, too. */
+ SetPageUptodate(page);
+ /*
+ * Set the page and all its buffers dirty and mark the inode
+ * dirty, too. The VM will write the page later on.
+ */
+ set_page_dirty(page);
+ /* Finally unlock and release the page. */
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ /* If there is a last partial page, need to do it the slow way. */
+ if (end_ofs) {
+ page = read_cache_page(mapping, idx,
+ (filler_t*)mapping->a_ops->readpage, NULL);
+ if (IS_ERR(page)) {
+ ntfs_error(vol->sb, "Failed to read last partial page "
+ "(sync error, index 0x%lx).", idx);
+ return PTR_ERR(page);
+ }
+ wait_on_page_locked(page);
+ if (unlikely(!PageUptodate(page))) {
+ ntfs_error(vol->sb, "Failed to read last partial page "
+ "(async error, index 0x%lx).", idx);
+ page_cache_release(page);
+ return PTR_ERR(page);
+ }
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr, val, end_ofs);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ set_page_dirty(page);
+ page_cache_release(page);
+ }
+done:
+ ntfs_debug("Done.");
+ return 0;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff