langsmoke/ref_c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <assert.h>
#include <ctype.h>
#include <time.h>
#include <limits.h>
#include <float.h>
#include <stdarg.h>
#include <stddef.h>
#include <locale.h>
#include <errno.h>
<signal.h> <setjmp.h> <time.h> <complex.h> <fenv.h> <inttypes.h> <stdbool.h> <stdalign.h> <stdatomic.h> <stdnoreturn.h>
auto bool break case char const continue default do double else enum
extern false float for goto if inline int long register
restrict return short signed sizeof static static_assert struct switch
typedef union unsigned void volatile while
#define #undef #if #ifdef #ifndef #elif #else #endif #include #define #undef #line #error #pragma
uint8_t uint16_t uint32_t uint64_t int8_t int16_t int32_t int64_t
fseek(f, 0, SEEK_END); size = ftell(f); rewind(f);
assert(size + B <= MEM);
assert(fread(&m[B], sizeof(unsigned char), size, f) == size);
fclose(f);
static int32_t mrlec(unsigned char * in, int32_t inlen, unsigned char * out) {
    unsigned char * ip = in;
    unsigned char * in_end = in + inlen;
    int32_t op = 0;
    int32_t c, pc = -1;
    int32_t t[256] = { 0 };
    int32_t run = 0;
    while ((c = (ip < in_end ? *ip++ : -1)) != -1) {
        if (c == pc)
            t[c] += (++run % 255) != 0;
        else
            --t[c], run = 0;
        pc = c;
    }
    for (int32_t i = 0; i < 32; ++i) {
        c = 0;
        for (int32_t j = 0; j < 8; ++j) c += (t[i * 8 + j] > 0) << j;
        out[op++] = c;
    }
    ip = in;
    c = pc = -1;
    run = 0;
    do {
        c = ip < in_end ? *ip++ : -1;
        if (c == pc)
            ++run;
        else if (run > 0 && t[pc] > 0) {
            out[op++] = pc;
            for (; run > 255; run -= 255) out[op++] = 255;
            out[op++] = run - 1;
            run = 1;
        } else
            for (++run; run > 1; --run) out[op++] = pc;
        pc = c;
    } while (c != -1);

    return op;
}
void put_int(int i) {
    if (i < 0) {
        putchar('-');
        i *= -1;
    }
    char buf[10];
    int j = 0;
    do {
        buf[j++] = i % 10 + '0';
        i /= 10;
    } while (i > 0);
    while (j > 0) putchar(buf[--j]);
}
int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn, ntfs_attr_search_ctx *ctx)
{
	VCN end_vcn;
	unsigned long flags;
	ntfs_inode *base_ni;
	MFT_RECORD *m;
	ATTR_RECORD *a;
	runlist_element *rl;
	struct page *put_this_page = NULL;
	int err = 0;
	bool ctx_is_temporary, ctx_needs_reset;
	ntfs_attr_search_ctx old_ctx = { NULL, };

	ntfs_debug("Mapping runlist part containing vcn 0x%llx.",
			(unsigned long long)vcn);
	if (!NInoAttr(ni))
		base_ni = ni;
	else
		base_ni = ni->ext.base_ntfs_ino;
	if (!ctx) {
		ctx_is_temporary = ctx_needs_reset = true;
		m = map_mft_record(base_ni);
		if (IS_ERR(m))
			return PTR_ERR(m);
		ctx = ntfs_attr_get_search_ctx(base_ni, m);
		if (unlikely(!ctx)) {
			err = -ENOMEM;
			goto err_out;
		}
	} else {
		VCN allocated_size_vcn;

		BUG_ON(IS_ERR(ctx->mrec));
		a = ctx->attr;
		BUG_ON(!a->non_resident);
		ctx_is_temporary = false;
		end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
		read_lock_irqsave(&ni->size_lock, flags);
		allocated_size_vcn = ni->allocated_size >>
				ni->vol->cluster_size_bits;
		read_unlock_irqrestore(&ni->size_lock, flags);
		if (!a->data.non_resident.lowest_vcn && end_vcn <= 0)
			end_vcn = allocated_size_vcn - 1;
		/*
		 * If we already have the attribute extent containing @vcn in
		 * @ctx, no need to look it up again.  We slightly cheat in
		 * that if vcn exceeds the allocated size, we will refuse to
		 * map the runlist below, so there is definitely no need to get
		 * the right attribute extent.
		 */
		if (vcn >= allocated_size_vcn || (a->type == ni->type &&
				a->name_length == ni->name_len &&
				!memcmp((u8*)a + le16_to_cpu(a->name_offset),
				ni->name, ni->name_len) &&
				sle64_to_cpu(a->data.non_resident.lowest_vcn)
				<= vcn && end_vcn >= vcn))
			ctx_needs_reset = false;
		else {
			/* Save the old search context. */
			old_ctx = *ctx;
			/*
			 * If the currently mapped (extent) inode is not the
			 * base inode we will unmap it when we reinitialize the
			 * search context which means we need to get a
			 * reference to the page containing the mapped mft
			 * record so we do not accidentally drop changes to the
			 * mft record when it has not been marked dirty yet.
			 */
			if (old_ctx.base_ntfs_ino && old_ctx.ntfs_ino !=
					old_ctx.base_ntfs_ino) {
				put_this_page = old_ctx.ntfs_ino->page;
				get_page(put_this_page);
			}
			/*
			 * Reinitialize the search context so we can lookup the
			 * needed attribute extent.
			 */
			ntfs_attr_reinit_search_ctx(ctx);
			ctx_needs_reset = true;
		}
	}
	if (ctx_needs_reset) {
		err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
				CASE_SENSITIVE, vcn, NULL, 0, ctx);
		if (unlikely(err)) {
			if (err == -ENOENT)
				err = -EIO;
			goto err_out;
		}
		BUG_ON(!ctx->attr->non_resident);
	}
	a = ctx->attr;
	/*
	 * Only decompress the mapping pairs if @vcn is inside it.  Otherwise
	 * we get into problems when we try to map an out of bounds vcn because
	 * we then try to map the already mapped runlist fragment and
	 * ntfs_mapping_pairs_decompress() fails.
	 */
	end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1;
	if (unlikely(vcn && vcn >= end_vcn)) {
		err = -ENOENT;
		goto err_out;
	}
	rl = ntfs_mapping_pairs_decompress(ni->vol, a, ni->runlist.rl);
	if (IS_ERR(rl))
		err = PTR_ERR(rl);
	else
		ni->runlist.rl = rl;
err_out:
	if (ctx_is_temporary) {
		if (likely(ctx))
			ntfs_attr_put_search_ctx(ctx);
		unmap_mft_record(base_ni);
	} else if (ctx_needs_reset) {
		/*
		 * If there is no attribute list, restoring the search context
		 * is accomplished simply by copying the saved context back over
		 * the caller supplied context.  If there is an attribute list,
		 * things are more complicated as we need to deal with mapping
		 * of mft records and resulting potential changes in pointers.
		 */
		if (NInoAttrList(base_ni)) {
			/*
			 * If the currently mapped (extent) inode is not the
			 * one we had before, we need to unmap it and map the
			 * old one.
			 */
			if (ctx->ntfs_ino != old_ctx.ntfs_ino) {
				/*
				 * If the currently mapped inode is not the
				 * base inode, unmap it.
				 */
				if (ctx->base_ntfs_ino && ctx->ntfs_ino !=
						ctx->base_ntfs_ino) {
					unmap_extent_mft_record(ctx->ntfs_ino);
					ctx->mrec = ctx->base_mrec;
					BUG_ON(!ctx->mrec);
				}
				/*
				 * If the old mapped inode is not the base
				 * inode, map it.
				 */
				if (old_ctx.base_ntfs_ino &&
						old_ctx.ntfs_ino !=
						old_ctx.base_ntfs_ino) {
retry_map:
					ctx->mrec = map_mft_record(
							old_ctx.ntfs_ino);
					/*
					 * Something bad has happened.  If out
					 * of memory retry till it succeeds.
					 * Any other errors are fatal and we
					 * return the error code in ctx->mrec.
					 * Let the caller deal with it...  We
					 * just need to fudge things so the
					 * caller can reinit and/or put the
					 * search context safely.
					 */
					if (IS_ERR(ctx->mrec)) {
						if (PTR_ERR(ctx->mrec) ==
								-ENOMEM) {
							schedule();
							goto retry_map;
						} else
							old_ctx.ntfs_ino =
								old_ctx.
								base_ntfs_ino;
					}
				}
			}
			/* Update the changed pointers in the saved context. */
			if (ctx->mrec != old_ctx.mrec) {
				if (!IS_ERR(ctx->mrec))
					old_ctx.attr = (ATTR_RECORD*)(
							(u8*)ctx->mrec +
							((u8*)old_ctx.attr -
							(u8*)old_ctx.mrec));
				old_ctx.mrec = ctx->mrec;
			}
		}
		/* Restore the search context to the saved one. */
		*ctx = old_ctx;
		/*
		 * We drop the reference on the page we took earlier.  In the
		 * case that IS_ERR(ctx->mrec) is true this means we might lose
		 * some changes to the mft record that had been made between
		 * the last time it was marked dirty/written out and now.  This
		 * at this stage is not a problem as the mapping error is fatal
		 * enough that the mft record cannot be written out anyway and
		 * the caller is very likely to shutdown the whole inode
		 * immediately and mark the volume dirty for chkdsk to pick up
		 * the pieces anyway.
		 */
		if (put_this_page)
			put_page(put_this_page);
	}
	return err;
}