X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fntfs%2Fattrib.c;h=1ff7f90a18b0a79b2c46351f692f40f7824e6917;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=fdf20b85ceb473d940a1240e4f3a71ab5d945095;hpb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;p=linux-2.6.git diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index fdf20b85c..1ff7f90a1 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -1,5 +1,5 @@ /** - * 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 @@ -21,915 +21,13 @@ */ #include -#include "ntfs.h" -#include "dir.h" - -/* Temporary helper functions -- might become macros */ - -/** - * 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 and 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_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); - - 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 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_merge - test if two runlists can be joined together and merge them - * @dst: original, destination runlist - * @src: new runlist to merge with @dst - * - * Test if two runlists 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 runlist @dst. - * - * It is up to the caller to serialize access to the runlists @dst and @src. - * - * Return: TRUE Success, the runlists have been merged. - * FALSE Failure, the runlists cannot be merged and have not been - * modified. - */ -static inline BOOL ntfs_rl_merge(runlist_element *dst, runlist_element *src) -{ - BOOL merge = ntfs_are_rl_mergeable(dst, src); - - if (merge) - __ntfs_rl_merge(dst, src); - return merge; -} - -/** - * 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; - 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 runlists. - */ - - /* 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 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; - 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 runlist. - */ - - 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 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) -{ - 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 runlists. - */ - 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 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_merge_runlists - 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_merge_runlists(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++) - ; - 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)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)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.", - (unsigned long long) - drl[ds].lcn); - drl[ds].lcn = (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)LCN_ENOENT) { - ds--; - slots = 1; - } - if (drl[ds].lcn != (LCN)LCN_RL_NOT_MAPPED) { - /* Add an unmapped runlist 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 runlist:"); - 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 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 *decompress_mapping_pairs(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); - } - /* 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 = (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) { - 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)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; - /* - * 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)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 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_merge_runlists(old_rl, rl); - if (likely(!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); -} +#include "attrib.h" +#include "debug.h" +#include "layout.h" +#include "mft.h" +#include "ntfs.h" +#include "types.h" /** * ntfs_map_runlist - map (a part of) a runlist of an ntfs inode @@ -973,10 +71,11 @@ int ntfs_map_runlist(ntfs_inode *ni, VCN vcn) down_write(&ni->runlist.lock); /* Make sure someone else didn't do the work while we were sleeping. */ - if (likely(ntfs_vcn_to_lcn(ni->runlist.rl, vcn) <= LCN_RL_NOT_MAPPED)) { + 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, + rl = ntfs_mapping_pairs_decompress(ni->vol, ctx->attr, ni->runlist.rl); if (IS_ERR(rl)) err = PTR_ERR(rl); @@ -992,63 +91,6 @@ err_out: return err; } -/** - * ntfs_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 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 runlist which has not been - * inserted into the runlist yet. - * -3 = 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. - */ -LCN ntfs_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)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; - } - } - /* - * 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; -} - /** * ntfs_find_vcn - find a vcn in the runlist described by an ntfs inode * @ni: ntfs inode describing the runlist to search @@ -1104,7 +146,7 @@ lock_retry_remap: if (likely(rl && vcn >= rl[0].vcn)) { while (likely(rl->length)) { if (likely(vcn < rl[1].vcn)) { - if (likely(rl->lcn >= (LCN)LCN_HOLE)) { + if (likely(rl->lcn >= LCN_HOLE)) { ntfs_debug("Done."); return rl; } @@ -1112,8 +154,8 @@ lock_retry_remap: } rl++; } - if (likely(rl->lcn != (LCN)LCN_RL_NOT_MAPPED)) { - if (likely(rl->lcn == (LCN)LCN_ENOENT)) + if (likely(rl->lcn != LCN_RL_NOT_MAPPED)) { + if (likely(rl->lcn == LCN_ENOENT)) err = -ENOENT; else err = -EIO; @@ -1208,19 +250,10 @@ static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name, const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx) { ATTR_RECORD *a; - ntfs_volume *vol; - ntfschar *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. @@ -1312,7 +345,7 @@ static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name, return -ENOENT; } } - ntfs_error(NULL, "Inode is corrupt. Run chkdsk."); + ntfs_error(vol->sb, "Inode is corrupt. Run chkdsk."); NVolSetErrors(vol); return -EIO; } @@ -1362,14 +395,14 @@ int load_attribute_list(ntfs_volume *vol, runlist *runlist, u8 *al_start, rl = runlist->rl; /* Read all clusters specified by the runlist one run at a time. */ while (rl->length) { - lcn = ntfs_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, "ntfs_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; @@ -1622,7 +655,6 @@ static int ntfs_external_attr_find(const ATTR_TYPE type, ctx->mrec = map_extent_mft_record(base_ni, le64_to_cpu( al_entry->mft_reference), &ni); - ctx->ntfs_ino = ni; if (IS_ERR(ctx->mrec)) { ntfs_error(vol->sb, "Failed to map " "extent mft record " @@ -1634,8 +666,11 @@ static int ntfs_external_attr_find(const ATTR_TYPE type, 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)); @@ -1707,7 +742,8 @@ do_next_attr: 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; @@ -1908,3 +944,315 @@ void ntfs_attr_put_search_ctx(ntfs_attr_search_ctx *ctx) kmem_cache_free(ntfs_attr_ctx_cache, ctx); 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; +}