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usbloadergx/libcustomntfs/compress.c
dimok321 0f17471b27 *Removed ntfs/fat source and added them as custom libs (makes them easier to update later) 
*Added sources of the custom libs to the branches
*Fixed crash when switching from list layout to grid/carousel layout
*Removed 1:1 copy option because its meaningless and almost the same as installing all partitions
*Fixed install partition selection. This option needs a reset. Go to settings and reselect your option for this.
*Fixed schinese and tchinese language modes (filename bugs. has to be schinese.lang and tchinese.lang like on SVN)
*Fixed bug in sound buffer circle
*Fixed incorrect behaviour of x-flip when selecting system like (thx Cyan for the patch)
*Accept ios revision 65535 for Waninkokos IOSes (thx to PPSainity for pointing it out)
*Merged the new theming style branch into trunk. Just as a reminder: ALL old themes will not work until the themers did port it to the new style!
*Removed old theme style completely

Theme example:
The example file of the theme is the Default.them file. It can be found in the SVN trunk.

Change in loading of themes:
When selecting a theme now a list of all .them files in a folder is displayed. The image folder of that theme has to be in the same folder as the .them file. The image path is defined in the head of the .them file in the line with "Image-Folder: Example\n".
2010-12-26 17:02:14 +00:00

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/**
* compress.c - Compressed attribute handling code. Originated from the Linux-NTFS
* project.
*
* Copyright (c) 2004-2005 Anton Altaparmakov
* Copyright (c) 2004-2006 Szabolcs Szakacsits
* Copyright (c) 2005 Yura Pakhuchiy
* Copyright (c) 2009-2010 Jean-Pierre Andre
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the NTFS-3G
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* A part of the compression algorithm is based on lzhuf.c whose header
* describes the roles of the original authors (with no apparent copyright
* notice, and according to http://home.earthlink.net/~neilbawd/pall.html
* this was put into public domain in 1988 by Haruhiko OKUMURA).
*
* LZHUF.C English version 1.0
* Based on Japanese version 29-NOV-1988
* LZSS coded by Haruhiko OKUMURA
* Adaptive Huffman Coding coded by Haruyasu YOSHIZAKI
* Edited and translated to English by Kenji RIKITAKE
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_STDIO_H
#include <stdio.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include "attrib.h"
#include "debug.h"
#include "volume.h"
#include "types.h"
#include "layout.h"
#include "runlist.h"
#include "compress.h"
#include "lcnalloc.h"
#include "logging.h"
#include "misc.h"
/**
* enum ntfs_compression_constants - constants used in the compression code
*/
typedef enum {
/* Token types and access mask. */
NTFS_SYMBOL_TOKEN = 0,
NTFS_PHRASE_TOKEN = 1,
NTFS_TOKEN_MASK = 1,
/* Compression sub-block constants. */
NTFS_SB_SIZE_MASK = 0x0fff,
NTFS_SB_SIZE = 0x1000,
NTFS_SB_IS_COMPRESSED = 0x8000,
} ntfs_compression_constants;
#define THRESHOLD 3 /* minimal match length for compression */
#define NIL NTFS_SB_SIZE /* End of tree's node */
struct COMPRESS_CONTEXT {
const unsigned char *inbuf;
unsigned int len;
unsigned int nbt;
int match_position;
unsigned int match_length;
u16 lson[NTFS_SB_SIZE + 1];
u16 rson[NTFS_SB_SIZE + 257];
u16 dad[NTFS_SB_SIZE + 1];
} ;
/*
* Initialize the match tree
*/
static void ntfs_init_compress_tree(struct COMPRESS_CONTEXT *pctx)
{
int i;
for (i = NTFS_SB_SIZE + 1; i <= NTFS_SB_SIZE + 256; i++)
pctx->rson[i] = NIL; /* root */
for (i = 0; i < NTFS_SB_SIZE; i++)
pctx->dad[i] = NIL; /* node */
}
/*
* Insert a new node into match tree for quickly locating
* further similar strings
*/
static void ntfs_new_node (struct COMPRESS_CONTEXT *pctx,
unsigned int r)
{
unsigned int pp;
BOOL less;
BOOL done;
const unsigned char *key;
int c;
unsigned long mxi;
unsigned int mxl;
mxl = (1 << (16 - pctx->nbt)) + 2;
less = FALSE;
done = FALSE;
key = &pctx->inbuf[r];
pp = NTFS_SB_SIZE + 1 + key[0];
pctx->rson[r] = pctx->lson[r] = NIL;
pctx->match_length = 0;
do {
if (!less) {
if (pctx->rson[pp] != NIL)
pp = pctx->rson[pp];
else {
pctx->rson[pp] = r;
pctx->dad[r] = pp;
done = TRUE;
}
} else {
if (pctx->lson[pp] != NIL)
pp = pctx->lson[pp];
else {
pctx->lson[pp] = r;
pctx->dad[r] = pp;
done = TRUE;
}
}
if (!done) {
register unsigned long i;
register const unsigned char *p1,*p2;
i = 1;
mxi = NTFS_SB_SIZE - r;
if (mxi < 2)
less = FALSE;
else {
p1 = key;
p2 = &pctx->inbuf[pp];
/* this loop has a significant impact on performances */
do {
} while ((p1[i] == p2[i]) && (++i < mxi));
less = (i < mxi) && (p1[i] < p2[i]);
}
if (i >= THRESHOLD) {
if (i > pctx->match_length) {
pctx->match_position =
r - pp + 2*NTFS_SB_SIZE - 1;
if ((pctx->match_length = i) > mxl) {
i = pctx->rson[pp];
pctx->rson[r] = i;
pctx->dad[i] = r;
i = pctx->lson[pp];
pctx->lson[r] = i;
pctx->dad[i] = r;
i = pctx->dad[pp];
pctx->dad[r] = i;
if (pctx->rson[i] == pp)
pctx->rson[i] = r;
else
pctx->lson[i] = r;
/* remove pp */
pctx->dad[pp] = NIL;
done = TRUE;
pctx->match_length = mxl;
}
} else
if ((i == pctx->match_length)
&& ((c = (r - pp + 2*NTFS_SB_SIZE - 1))
< pctx->match_position))
pctx->match_position = c;
}
}
} while (!done);
}
/*
* Search for the longest previous string matching the
* current one
*
* Returns the end of the longest current string which matched
* or zero if there was a bug
*/
static unsigned int ntfs_nextmatch(struct COMPRESS_CONTEXT *pctx,
unsigned int rr, int dd)
{
unsigned int bestlen = 0;
do {
rr++;
if (pctx->match_length > 0)
pctx->match_length--;
if (!pctx->len) {
ntfs_log_error("compress bug : void run\n");
goto bug;
}
if (--pctx->len) {
if (rr >= NTFS_SB_SIZE) {
ntfs_log_error("compress bug : buffer overflow\n");
goto bug;
}
if (((rr + bestlen) < NTFS_SB_SIZE)) {
while ((unsigned int)(1 << pctx->nbt)
<= (rr - 1))
pctx->nbt++;
ntfs_new_node(pctx,rr);
if (pctx->match_length > bestlen)
bestlen = pctx->match_length;
} else
if (dd > 0) {
rr += dd;
if ((int)pctx->match_length > dd)
pctx->match_length -= dd;
else
pctx->match_length = 0;
if ((int)pctx->len < dd) {
ntfs_log_error("compress bug : run overflows\n");
goto bug;
}
pctx->len -= dd;
dd = 0;
}
}
} while (dd-- > 0);
return (rr);
bug :
return (0);
}
/*
* Compress an input block
*
* Returns the size of the compressed block (including header)
* or zero if there was an error
*/
static unsigned int ntfs_compress_block(const char *inbuf,
unsigned int size, char *outbuf)
{
struct COMPRESS_CONTEXT *pctx;
char *ptag;
int dd;
unsigned int rr;
unsigned int last_match_length;
unsigned int q;
unsigned int xout;
unsigned int ntag;
pctx = (struct COMPRESS_CONTEXT*)malloc(sizeof(struct COMPRESS_CONTEXT));
if (pctx) {
pctx->inbuf = (const unsigned char*)inbuf;
ntfs_init_compress_tree(pctx);
xout = 2;
ntag = 0;
ptag = &outbuf[xout++];
*ptag = 0;
rr = 0;
pctx->nbt = 4;
pctx->len = size;
pctx->match_length = 0;
ntfs_new_node(pctx,0);
do {
if (pctx->match_length > pctx->len)
pctx->match_length = pctx->len;
if (pctx->match_length < THRESHOLD) {
pctx->match_length = 1;
if (ntag >= 8) {
ntag = 0;
ptag = &outbuf[xout++];
*ptag = 0;
}
outbuf[xout++] = inbuf[rr];
ntag++;
} else {
while ((unsigned int)(1 << pctx->nbt)
<= (rr - 1))
pctx->nbt++;
q = (pctx->match_position << (16 - pctx->nbt))
+ pctx->match_length - THRESHOLD;
if (ntag >= 8) {
ntag = 0;
ptag = &outbuf[xout++];
*ptag = 0;
}
*ptag |= 1 << ntag++;
outbuf[xout++] = q & 255;
outbuf[xout++] = (q >> 8) & 255;
}
last_match_length = pctx->match_length;
dd = last_match_length;
if (dd-- > 0) {
rr = ntfs_nextmatch(pctx,rr,dd);
if (!rr)
goto bug;
}
/*
* stop if input is exhausted or output has exceeded
* the maximum size. Two extra bytes have to be
* reserved in output buffer, as 3 bytes may be
* output in a loop.
*/
} while ((pctx->len > 0)
&& (rr < size) && (xout < (NTFS_SB_SIZE + 2)));
/* uncompressed must be full size, so accept if better */
if (xout < (NTFS_SB_SIZE + 2)) {
outbuf[0] = (xout - 3) & 255;
outbuf[1] = 0xb0 + (((xout - 3) >> 8) & 15);
} else {
memcpy(&outbuf[2],inbuf,size);
if (size < NTFS_SB_SIZE)
memset(&outbuf[size+2],0,NTFS_SB_SIZE - size);
outbuf[0] = 0xff;
outbuf[1] = 0x3f;
xout = NTFS_SB_SIZE + 2;
}
free(pctx);
} else {
xout = 0;
errno = ENOMEM;
}
return (xout); /* 0 for an error, > size if cannot compress */
bug :
return (0);
}
/**
* ntfs_decompress - decompress a compression block into an array of pages
* @dest: buffer to which to write the decompressed data
* @dest_size: size of buffer @dest in bytes
* @cb_start: compression block to decompress
* @cb_size: size of compression block @cb_start in bytes
*
* This decompresses the compression block @cb_start into the destination
* buffer @dest.
*
* @cb_start is a pointer to the compression block which needs decompressing
* and @cb_size is the size of @cb_start in bytes (8-64kiB).
*
* Return 0 if success or -EOVERFLOW on error in the compressed stream.
*/
static int ntfs_decompress(u8 *dest, const u32 dest_size,
u8 *const cb_start, const u32 cb_size)
{
/*
* Pointers into the compressed data, i.e. the compression block (cb),
* and the therein contained sub-blocks (sb).
*/
u8 *cb_end = cb_start + cb_size; /* End of cb. */
u8 *cb = cb_start; /* Current position in cb. */
u8 *cb_sb_start = cb; /* Beginning of the current sb in the cb. */
u8 *cb_sb_end; /* End of current sb / beginning of next sb. */
/* Variables for uncompressed data / destination. */
u8 *dest_end = dest + dest_size; /* End of dest buffer. */
u8 *dest_sb_start; /* Start of current sub-block in dest. */
u8 *dest_sb_end; /* End of current sb in dest. */
/* Variables for tag and token parsing. */
u8 tag; /* Current tag. */
int token; /* Loop counter for the eight tokens in tag. */
ntfs_log_trace("Entering, cb_size = 0x%x.\n", (unsigned)cb_size);
do_next_sb:
ntfs_log_debug("Beginning sub-block at offset = %d in the cb.\n",
(int)(cb - cb_start));
/*
* Have we reached the end of the compression block or the end of the
* decompressed data? The latter can happen for example if the current
* position in the compression block is one byte before its end so the
* first two checks do not detect it.
*/
if (cb == cb_end || !le16_to_cpup((le16*)cb) || dest == dest_end) {
ntfs_log_debug("Completed. Returning success (0).\n");
return 0;
}
/* Setup offset for the current sub-block destination. */
dest_sb_start = dest;
dest_sb_end = dest + NTFS_SB_SIZE;
/* Check that we are still within allowed boundaries. */
if (dest_sb_end > dest_end)
goto return_overflow;
/* Does the minimum size of a compressed sb overflow valid range? */
if (cb + 6 > cb_end)
goto return_overflow;
/* Setup the current sub-block source pointers and validate range. */
cb_sb_start = cb;
cb_sb_end = cb_sb_start + (le16_to_cpup((le16*)cb) & NTFS_SB_SIZE_MASK)
+ 3;
if (cb_sb_end > cb_end)
goto return_overflow;
/* Now, we are ready to process the current sub-block (sb). */
if (!(le16_to_cpup((le16*)cb) & NTFS_SB_IS_COMPRESSED)) {
ntfs_log_debug("Found uncompressed sub-block.\n");
/* This sb is not compressed, just copy it into destination. */
/* Advance source position to first data byte. */
cb += 2;
/* An uncompressed sb must be full size. */
if (cb_sb_end - cb != NTFS_SB_SIZE)
goto return_overflow;
/* Copy the block and advance the source position. */
memcpy(dest, cb, NTFS_SB_SIZE);
cb += NTFS_SB_SIZE;
/* Advance destination position to next sub-block. */
dest += NTFS_SB_SIZE;
goto do_next_sb;
}
ntfs_log_debug("Found compressed sub-block.\n");
/* This sb is compressed, decompress it into destination. */
/* Forward to the first tag in the sub-block. */
cb += 2;
do_next_tag:
if (cb == cb_sb_end) {
/* Check if the decompressed sub-block was not full-length. */
if (dest < dest_sb_end) {
int nr_bytes = dest_sb_end - dest;
ntfs_log_debug("Filling incomplete sub-block with zeroes.\n");
/* Zero remainder and update destination position. */
memset(dest, 0, nr_bytes);
dest += nr_bytes;
}
/* We have finished the current sub-block. */
goto do_next_sb;
}
/* Check we are still in range. */
if (cb > cb_sb_end || dest > dest_sb_end)
goto return_overflow;
/* Get the next tag and advance to first token. */
tag = *cb++;
/* Parse the eight tokens described by the tag. */
for (token = 0; token < 8; token++, tag >>= 1) {
u16 lg, pt, length, max_non_overlap;
register u16 i;
u8 *dest_back_addr;
/* Check if we are done / still in range. */
if (cb >= cb_sb_end || dest > dest_sb_end)
break;
/* Determine token type and parse appropriately.*/
if ((tag & NTFS_TOKEN_MASK) == NTFS_SYMBOL_TOKEN) {
/*
* We have a symbol token, copy the symbol across, and
* advance the source and destination positions.
*/
*dest++ = *cb++;
/* Continue with the next token. */
continue;
}
/*
* We have a phrase token. Make sure it is not the first tag in
* the sb as this is illegal and would confuse the code below.
*/
if (dest == dest_sb_start)
goto return_overflow;
/*
* Determine the number of bytes to go back (p) and the number
* of bytes to copy (l). We use an optimized algorithm in which
* we first calculate log2(current destination position in sb),
* which allows determination of l and p in O(1) rather than
* O(n). We just need an arch-optimized log2() function now.
*/
lg = 0;
for (i = dest - dest_sb_start - 1; i >= 0x10; i >>= 1)
lg++;
/* Get the phrase token into i. */
pt = le16_to_cpup((le16*)cb);
/*
* Calculate starting position of the byte sequence in
* the destination using the fact that p = (pt >> (12 - lg)) + 1
* and make sure we don't go too far back.
*/
dest_back_addr = dest - (pt >> (12 - lg)) - 1;
if (dest_back_addr < dest_sb_start)
goto return_overflow;
/* Now calculate the length of the byte sequence. */
length = (pt & (0xfff >> lg)) + 3;
/* Verify destination is in range. */
if (dest + length > dest_sb_end)
goto return_overflow;
/* The number of non-overlapping bytes. */
max_non_overlap = dest - dest_back_addr;
if (length <= max_non_overlap) {
/* The byte sequence doesn't overlap, just copy it. */
memcpy(dest, dest_back_addr, length);
/* Advance destination pointer. */
dest += length;
} else {
/*
* The byte sequence does overlap, copy non-overlapping
* part and then do a slow byte by byte copy for the
* overlapping part. Also, advance the destination
* pointer.
*/
memcpy(dest, dest_back_addr, max_non_overlap);
dest += max_non_overlap;
dest_back_addr += max_non_overlap;
length -= max_non_overlap;
while (length--)
*dest++ = *dest_back_addr++;
}
/* Advance source position and continue with the next token. */
cb += 2;
}
/* No tokens left in the current tag. Continue with the next tag. */
goto do_next_tag;
return_overflow:
errno = EOVERFLOW;
ntfs_log_perror("Failed to decompress file");
return -1;
}
/**
* ntfs_is_cb_compressed - internal function, do not use
*
* This is a very specialised function determining if a cb is compressed or
* uncompressed. It is assumed that checking for a sparse cb has already been
* performed and that the cb is not sparse. It makes all sorts of other
* assumptions as well and hence it is not useful anywhere other than where it
* is used at the moment. Please, do not make this function available for use
* outside of compress.c as it is bound to confuse people and not do what they
* want.
*
* Return TRUE on errors so that the error will be detected later on in the
* code. Might be a bit confusing to debug but there really should never be
* errors coming from here.
*/
static BOOL ntfs_is_cb_compressed(ntfs_attr *na, runlist_element *rl,
VCN cb_start_vcn, int cb_clusters)
{
/*
* The simplest case: the run starting at @cb_start_vcn contains
* @cb_clusters clusters which are all not sparse, thus the cb is not
* compressed.
*/
restart:
cb_clusters -= rl->length - (cb_start_vcn - rl->vcn);
while (cb_clusters > 0) {
/* Go to the next run. */
rl++;
/* Map the next runlist fragment if it is not mapped. */
if (rl->lcn < LCN_HOLE || !rl->length) {
cb_start_vcn = rl->vcn;
rl = ntfs_attr_find_vcn(na, rl->vcn);
if (!rl || rl->lcn < LCN_HOLE || !rl->length)
return TRUE;
/*
* If the runs were merged need to deal with the
* resulting partial run so simply restart.
*/
if (rl->vcn < cb_start_vcn)
goto restart;
}
/* If the current run is sparse, the cb is compressed. */
if (rl->lcn == LCN_HOLE)
return TRUE;
/* If the whole cb is not sparse, it is not compressed. */
if (rl->length >= cb_clusters)
return FALSE;
cb_clusters -= rl->length;
};
/* All cb_clusters were not sparse thus the cb is not compressed. */
return FALSE;
}
/**
* ntfs_compressed_attr_pread - read from a compressed attribute
* @na: ntfs attribute to read from
* @pos: byte position in the attribute to begin reading from
* @count: number of bytes to read
* @b: output data buffer
*
* NOTE: You probably want to be using attrib.c::ntfs_attr_pread() instead.
*
* This function will read @count bytes starting at offset @pos from the
* compressed ntfs attribute @na into the data buffer @b.
*
* On success, return the number of successfully read bytes. If this number
* is lower than @count this means that the read reached end of file or that
* an error was encountered during the read so that the read is partial.
* 0 means end of file or nothing was read (also return 0 when @count is 0).
*
* On error and nothing has been read, return -1 with errno set appropriately
* to the return code of ntfs_pread(), or to EINVAL in case of invalid
* arguments.
*/
s64 ntfs_compressed_attr_pread(ntfs_attr *na, s64 pos, s64 count, void *b)
{
s64 br, to_read, ofs, total, total2;
u64 cb_size_mask;
VCN start_vcn, vcn, end_vcn;
ntfs_volume *vol;
runlist_element *rl;
u8 *dest, *cb, *cb_pos, *cb_end;
u32 cb_size;
int err;
ATTR_FLAGS data_flags;
FILE_ATTR_FLAGS compression;
unsigned int nr_cbs, cb_clusters;
ntfs_log_trace("Entering for inode 0x%llx, attr 0x%x, pos 0x%llx, count 0x%llx.\n",
(unsigned long long)na->ni->mft_no, na->type,
(long long)pos, (long long)count);
data_flags = na->data_flags;
compression = na->ni->flags & FILE_ATTR_COMPRESSED;
if (!na || !na->ni || !na->ni->vol || !b
|| ((data_flags & ATTR_COMPRESSION_MASK)
!= ATTR_IS_COMPRESSED)
|| pos < 0 || count < 0) {
errno = EINVAL;
return -1;
}
/*
* Encrypted attributes are not supported. We return access denied,
* which is what Windows NT4 does, too.
*/
if (NAttrEncrypted(na)) {
errno = EACCES;
return -1;
}
if (!count)
return 0;
/* Truncate reads beyond end of attribute. */
if (pos + count > na->data_size) {
if (pos >= na->data_size) {
return 0;
}
count = na->data_size - pos;
}
/* If it is a resident attribute, simply use ntfs_attr_pread(). */
if (!NAttrNonResident(na))
return ntfs_attr_pread(na, pos, count, b);
total = total2 = 0;
/* Zero out reads beyond initialized size. */
if (pos + count > na->initialized_size) {
if (pos >= na->initialized_size) {
memset(b, 0, count);
return count;
}
total2 = pos + count - na->initialized_size;
count -= total2;
memset((u8*)b + count, 0, total2);
}
vol = na->ni->vol;
cb_size = na->compression_block_size;
cb_size_mask = cb_size - 1UL;
cb_clusters = na->compression_block_clusters;
/* Need a temporary buffer for each loaded compression block. */
cb = (u8*)ntfs_malloc(cb_size);
if (!cb)
return -1;
/* Need a temporary buffer for each uncompressed block. */
dest = (u8*)ntfs_malloc(cb_size);
if (!dest) {
free(cb);
return -1;
}
/*
* The first vcn in the first compression block (cb) which we need to
* decompress.
*/
start_vcn = (pos & ~cb_size_mask) >> vol->cluster_size_bits;
/* Offset in the uncompressed cb at which to start reading data. */
ofs = pos & cb_size_mask;
/*
* The first vcn in the cb after the last cb which we need to
* decompress.
*/
end_vcn = ((pos + count + cb_size - 1) & ~cb_size_mask) >>
vol->cluster_size_bits;
/* Number of compression blocks (cbs) in the wanted vcn range. */
nr_cbs = (end_vcn - start_vcn) << vol->cluster_size_bits >>
na->compression_block_size_bits;
cb_end = cb + cb_size;
do_next_cb:
nr_cbs--;
cb_pos = cb;
vcn = start_vcn;
start_vcn += cb_clusters;
/* Check whether the compression block is sparse. */
rl = ntfs_attr_find_vcn(na, vcn);
if (!rl || rl->lcn < LCN_HOLE) {
free(cb);
free(dest);
if (total)
return total;
/* FIXME: Do we want EIO or the error code? (AIA) */
errno = EIO;
return -1;
}
if (rl->lcn == LCN_HOLE) {
/* Sparse cb, zero out destination range overlapping the cb. */
ntfs_log_debug("Found sparse compression block.\n");
to_read = min(count, cb_size - ofs);
memset(b, 0, to_read);
ofs = 0;
total += to_read;
count -= to_read;
b = (u8*)b + to_read;
} else if (!ntfs_is_cb_compressed(na, rl, vcn, cb_clusters)) {
s64 tdata_size, tinitialized_size;
/*
* Uncompressed cb, read it straight into the destination range
* overlapping the cb.
*/
ntfs_log_debug("Found uncompressed compression block.\n");
/*
* Read the uncompressed data into the destination buffer.
* NOTE: We cheat a little bit here by marking the attribute as
* not compressed in the ntfs_attr structure so that we can
* read the data by simply using ntfs_attr_pread(). (-8
* NOTE: we have to modify data_size and initialized_size
* temporarily as well...
*/
to_read = min(count, cb_size - ofs);
ofs += vcn << vol->cluster_size_bits;
NAttrClearCompressed(na);
na->data_flags &= ~ATTR_COMPRESSION_MASK;
tdata_size = na->data_size;
tinitialized_size = na->initialized_size;
na->data_size = na->initialized_size = na->allocated_size;
do {
br = ntfs_attr_pread(na, ofs, to_read, b);
if (br <= 0) {
if (!br) {
ntfs_log_error("Failed to read an"
" uncompressed cluster,"
" inode %lld offs 0x%llx\n",
(long long)na->ni->mft_no,
(long long)ofs);
errno = EIO;
}
err = errno;
na->data_size = tdata_size;
na->initialized_size = tinitialized_size;
na->ni->flags |= compression;
na->data_flags = data_flags;
free(cb);
free(dest);
if (total)
return total;
errno = err;
return br;
}
total += br;
count -= br;
b = (u8*)b + br;
to_read -= br;
ofs += br;
} while (to_read > 0);
na->data_size = tdata_size;
na->initialized_size = tinitialized_size;
na->ni->flags |= compression;
na->data_flags = data_flags;
ofs = 0;
} else {
s64 tdata_size, tinitialized_size;
/*
* Compressed cb, decompress it into the temporary buffer, then
* copy the data to the destination range overlapping the cb.
*/
ntfs_log_debug("Found compressed compression block.\n");
/*
* Read the compressed data into the temporary buffer.
* NOTE: We cheat a little bit here by marking the attribute as
* not compressed in the ntfs_attr structure so that we can
* read the raw, compressed data by simply using
* ntfs_attr_pread(). (-8
* NOTE: We have to modify data_size and initialized_size
* temporarily as well...
*/
to_read = cb_size;
NAttrClearCompressed(na);
na->data_flags &= ~ATTR_COMPRESSION_MASK;
tdata_size = na->data_size;
tinitialized_size = na->initialized_size;
na->data_size = na->initialized_size = na->allocated_size;
do {
br = ntfs_attr_pread(na,
(vcn << vol->cluster_size_bits) +
(cb_pos - cb), to_read, cb_pos);
if (br <= 0) {
if (!br) {
ntfs_log_error("Failed to read a"
" compressed cluster, "
" inode %lld offs 0x%llx\n",
(long long)na->ni->mft_no,
(long long)(vcn << vol->cluster_size_bits));
errno = EIO;
}
err = errno;
na->data_size = tdata_size;
na->initialized_size = tinitialized_size;
na->ni->flags |= compression;
na->data_flags = data_flags;
free(cb);
free(dest);
if (total)
return total;
errno = err;
return br;
}
cb_pos += br;
to_read -= br;
} while (to_read > 0);
na->data_size = tdata_size;
na->initialized_size = tinitialized_size;
na->ni->flags |= compression;
na->data_flags = data_flags;
/* Just a precaution. */
if (cb_pos + 2 <= cb_end)
*(u16*)cb_pos = 0;
ntfs_log_debug("Successfully read the compression block.\n");
if (ntfs_decompress(dest, cb_size, cb, cb_size) < 0) {
err = errno;
free(cb);
free(dest);
if (total)
return total;
errno = err;
return -1;
}
to_read = min(count, cb_size - ofs);
memcpy(b, dest + ofs, to_read);
total += to_read;
count -= to_read;
b = (u8*)b + to_read;
ofs = 0;
}
/* Do we have more work to do? */
if (nr_cbs)
goto do_next_cb;
/* We no longer need the buffers. */
free(cb);
free(dest);
/* Return number of bytes read. */
return total + total2;
}
/*
* Read data from a set of clusters
*
* Returns the amount of data read
*/
static u32 read_clusters(ntfs_volume *vol, const runlist_element *rl,
s64 offs, u32 to_read, char *inbuf)
{
u32 count;
int xgot;
u32 got;
s64 xpos;
BOOL first;
char *xinbuf;
const runlist_element *xrl;
got = 0;
xrl = rl;
xinbuf = inbuf;
first = TRUE;
do {
count = xrl->length << vol->cluster_size_bits;
xpos = xrl->lcn << vol->cluster_size_bits;
if (first) {
count -= offs;
xpos += offs;
}
if ((to_read - got) < count)
count = to_read - got;
xgot = ntfs_pread(vol->dev, xpos, count, xinbuf);
if (xgot == (int)count) {
got += count;
xpos += count;
xinbuf += count;
xrl++;
}
first = FALSE;
} while ((xgot == (int)count) && (got < to_read));
return (got);
}
/*
* Write data to a set of clusters
*
* Returns the amount of data written
*/
static s32 write_clusters(ntfs_volume *vol, const runlist_element *rl,
s64 offs, s32 to_write, const char *outbuf)
{
s32 count;
s32 put, xput;
s64 xpos;
BOOL first;
const char *xoutbuf;
const runlist_element *xrl;
put = 0;
xrl = rl;
xoutbuf = outbuf;
first = TRUE;
do {
count = xrl->length << vol->cluster_size_bits;
xpos = xrl->lcn << vol->cluster_size_bits;
if (first) {
count -= offs;
xpos += offs;
}
if ((to_write - put) < count)
count = to_write - put;
xput = ntfs_pwrite(vol->dev, xpos, count, xoutbuf);
if (xput == count) {
put += count;
xpos += count;
xoutbuf += count;
xrl++;
}
first = FALSE;
} while ((xput == count) && (put < to_write));
return (put);
}
/*
* Compress and write a set of blocks
*
* returns the size actually written (rounded to a full cluster)
* or 0 if all zeroes (nothing is written)
* or -1 if could not compress (nothing is written)
* or -2 if there were an irrecoverable error (errno set)
*/
static s32 ntfs_comp_set(ntfs_attr *na, runlist_element *rl,
s64 offs, u32 insz, const char *inbuf)
{
ntfs_volume *vol;
char *outbuf;
char *pbuf;
u32 compsz;
s32 written;
s32 rounded;
unsigned int clsz;
u32 p;
unsigned int sz;
unsigned int bsz;
BOOL fail;
BOOL allzeroes;
/* a single compressed zero */
static char onezero[] = { 0x01, 0xb0, 0x00, 0x00 } ;
/* a couple of compressed zeroes */
static char twozeroes[] = { 0x02, 0xb0, 0x00, 0x00, 0x00 } ;
/* more compressed zeroes, to be followed by some count */
static char morezeroes[] = { 0x03, 0xb0, 0x02, 0x00 } ;
vol = na->ni->vol;
written = -1; /* default return */
clsz = 1 << vol->cluster_size_bits;
/* may need 2 extra bytes per block and 2 more bytes */
outbuf = (char*)ntfs_malloc(na->compression_block_size
+ 2*(na->compression_block_size/NTFS_SB_SIZE)
+ 2);
if (outbuf) {
fail = FALSE;
compsz = 0;
allzeroes = TRUE;
for (p=0; (p<insz) && !fail; p+=NTFS_SB_SIZE) {
if ((p + NTFS_SB_SIZE) < insz)
bsz = NTFS_SB_SIZE;
else
bsz = insz - p;
pbuf = &outbuf[compsz];
sz = ntfs_compress_block(&inbuf[p],bsz,pbuf);
/* fail if all the clusters (or more) are needed */
if (!sz || ((compsz + sz + clsz + 2)
> na->compression_block_size))
fail = TRUE;
else {
if (allzeroes) {
/* check whether this is all zeroes */
switch (sz) {
case 4 :
allzeroes = !memcmp(
pbuf,onezero,4);
break;
case 5 :
allzeroes = !memcmp(
pbuf,twozeroes,5);
break;
case 6 :
allzeroes = !memcmp(
pbuf,morezeroes,4);
break;
default :
allzeroes = FALSE;
break;
}
}
compsz += sz;
}
}
if (!fail && !allzeroes) {
/* add a couple of null bytes, space has been checked */
outbuf[compsz++] = 0;
outbuf[compsz++] = 0;
/* write a full cluster, to avoid partial reading */
rounded = ((compsz - 1) | (clsz - 1)) + 1;
written = write_clusters(vol, rl, offs, rounded, outbuf);
if (written != rounded) {
/*
* TODO : previously written text has been
* spoilt, should return a specific error
*/
ntfs_log_error("error writing compressed data\n");
errno = EIO;
written = -2;
}
} else
if (!fail)
written = 0;
free(outbuf);
}
return (written);
}
/*
* Check the validity of a compressed runlist
* The check starts at the beginning of current run and ends
* at the end of runlist
* errno is set if the runlist is not valid
*/
static BOOL valid_compressed_run(ntfs_attr *na, runlist_element *rl,
BOOL fullcheck, const char *text)
{
runlist_element *xrl;
const char *err;
BOOL ok = TRUE;
xrl = rl;
while (xrl->vcn & (na->compression_block_clusters - 1))
xrl--;
err = (const char*)NULL;
while (xrl->length) {
if ((xrl->vcn + xrl->length) != xrl[1].vcn)
err = "Runs not adjacent";
if (xrl->lcn == LCN_HOLE) {
if ((xrl->vcn + xrl->length)
& (na->compression_block_clusters - 1)) {
err = "Invalid hole";
}
if (fullcheck && (xrl[1].lcn == LCN_HOLE)) {
err = "Adjacent holes";
}
}
if (err) {
ntfs_log_error("%s at %s index %ld inode %lld\n",
err, text, (long)(xrl - na->rl),
(long long)na->ni->mft_no);
errno = EIO;
ok = FALSE;
err = (const char*)NULL;
}
xrl++;
}
return (ok);
}
/*
* Free unneeded clusters after overwriting compressed data
*
* This generally requires one or two empty slots at the end of runlist,
* but we do not want to reallocate the runlist here because
* there are many pointers to it.
* So the empty slots have to be reserved beforehand
*
* Returns zero unless some error occurred (described by errno)
*
* +======= start of block =====+
* 0 |A chunk may overflow | <-- rl usedcnt : A + B
* |A on previous block | then B
* |A |
* +-- end of allocated chunk --+ freelength : C
* |B | (incl overflow)
* +== end of compressed data ==+
* |C | <-- freerl freecnt : C + D
* |C chunk may overflow |
* |C on next block |
* +-- end of allocated chunk --+
* |D |
* |D chunk may overflow |
* 15 |D on next block |
* +======== end of block ======+
*
*/
static int ntfs_compress_overwr_free(ntfs_attr *na, runlist_element *rl,
s32 usedcnt, s32 freecnt, VCN *update_from)
{
BOOL beginhole;
BOOL mergeholes;
s32 oldlength;
s32 freelength;
s64 freelcn;
s64 freevcn;
runlist_element *freerl;
ntfs_volume *vol;
s32 carry;
int res;
vol = na->ni->vol;
res = 0;
freelcn = rl->lcn + usedcnt;
freevcn = rl->vcn + usedcnt;
freelength = rl->length - usedcnt;
beginhole = !usedcnt && !rl->vcn;
/* can merge with hole before ? */
mergeholes = !usedcnt
&& rl[0].vcn
&& (rl[-1].lcn == LCN_HOLE);
/* truncate current run, carry to subsequent hole */
carry = freelength;
oldlength = rl->length;
if (mergeholes) {
/* merging with a hole before */
freerl = rl;
} else {
rl->length -= freelength; /* warning : can be zero */
freerl = ++rl;
}
if (!mergeholes && (usedcnt || beginhole)) {
s32 freed;
runlist_element *frl;
runlist_element *erl;
int holes = 0;
BOOL threeparts;
/* free the unneeded clusters from initial run, then freerl */
threeparts = (freelength > freecnt);
freed = 0;
frl = freerl;
if (freelength) {
res = ntfs_cluster_free_basic(vol,freelcn,
(threeparts ? freecnt : freelength));
if (!res)
freed += (threeparts ? freecnt : freelength);
if (!usedcnt) {
holes++;
freerl--;
freerl->length += (threeparts
? freecnt : freelength);
if (freerl->vcn < *update_from)
*update_from = freerl->vcn;
}
}
while (!res && frl->length && (freed < freecnt)) {
if (frl->length <= (freecnt - freed)) {
res = ntfs_cluster_free_basic(vol, frl->lcn,
frl->length);
if (!res) {
freed += frl->length;
frl->lcn = LCN_HOLE;
frl->length += carry;
carry = 0;
holes++;
}
} else {
res = ntfs_cluster_free_basic(vol, frl->lcn,
freecnt - freed);
if (!res) {
frl->lcn += freecnt - freed;
frl->vcn += freecnt - freed;
frl->length -= freecnt - freed;
freed = freecnt;
}
}
frl++;
}
na->compressed_size -= freed << vol->cluster_size_bits;
switch (holes) {
case 0 :
/* there are no hole, must insert one */
/* space for hole has been prereserved */
if (freerl->lcn == LCN_HOLE) {
if (threeparts) {
erl = freerl;
while (erl->length)
erl++;
do {
erl[2] = *erl;
} while (erl-- != freerl);
freerl[1].length = freelength - freecnt;
freerl->length = freecnt;
freerl[1].lcn = freelcn + freecnt;
freerl[1].vcn = freevcn + freecnt;
freerl[2].lcn = LCN_HOLE;
freerl[2].vcn = freerl[1].vcn
+ freerl[1].length;
freerl->vcn = freevcn;
} else {
freerl->vcn = freevcn;
freerl->length += freelength;
}
} else {
erl = freerl;
while (erl->length)
erl++;
if (threeparts) {
do {
erl[2] = *erl;
} while (erl-- != freerl);
freerl[1].lcn = freelcn + freecnt;
freerl[1].vcn = freevcn + freecnt;
freerl[1].length = oldlength - usedcnt - freecnt;
} else {
do {
erl[1] = *erl;
} while (erl-- != freerl);
}
freerl->lcn = LCN_HOLE;
freerl->vcn = freevcn;
freerl->length = freecnt;
}
break;
case 1 :
/* there is a single hole, may have to merge */
freerl->vcn = freevcn;
if (freerl[1].lcn == LCN_HOLE) {
freerl->length += freerl[1].length;
erl = freerl;
do {
erl++;
*erl = erl[1];
} while (erl->length);
}
break;
default :
/* there were several holes, must merge them */
freerl->lcn = LCN_HOLE;
freerl->vcn = freevcn;
freerl->length = freecnt;
if (freerl[holes].lcn == LCN_HOLE) {
freerl->length += freerl[holes].length;
holes++;
}
erl = freerl;
do {
erl++;
*erl = erl[holes - 1];
} while (erl->length);
break;
}
} else {
s32 freed;
runlist_element *frl;
runlist_element *xrl;
freed = 0;
frl = freerl--;
if (freerl->vcn < *update_from)
*update_from = freerl->vcn;
while (!res && frl->length && (freed < freecnt)) {
if (frl->length <= (freecnt - freed)) {
freerl->length += frl->length;
freed += frl->length;
res = ntfs_cluster_free_basic(vol, frl->lcn,
frl->length);
frl++;
} else {
freerl->length += freecnt - freed;
res = ntfs_cluster_free_basic(vol, frl->lcn,
freecnt - freed);
frl->lcn += freecnt - freed;
frl->vcn += freecnt - freed;
frl->length -= freecnt - freed;
freed = freecnt;
}
}
/* remove unneded runlist entries */
xrl = freerl;
/* group with next run if also a hole */
if (frl->length && (frl->lcn == LCN_HOLE)) {
xrl->length += frl->length;
frl++;
}
while (frl->length) {
*++xrl = *frl++;
}
*++xrl = *frl; /* terminator */
na->compressed_size -= freed << vol->cluster_size_bits;
}
return (res);
}
/*
* Free unneeded clusters after compression
*
* This generally requires one or two empty slots at the end of runlist,
* but we do not want to reallocate the runlist here because
* there are many pointers to it.
* So the empty slots have to be reserved beforehand
*
* Returns zero unless some error occurred (described by errno)
*/
static int ntfs_compress_free(ntfs_attr *na, runlist_element *rl,
s64 used, s64 reserved, BOOL appending,
VCN *update_from)
{
s32 freecnt;
s32 usedcnt;
int res;
s64 freelcn;
s64 freevcn;
s32 freelength;
BOOL mergeholes;
BOOL beginhole;
ntfs_volume *vol;
runlist_element *freerl;
res = -1; /* default return */
vol = na->ni->vol;
freecnt = (reserved - used) >> vol->cluster_size_bits;
usedcnt = (reserved >> vol->cluster_size_bits) - freecnt;
if (rl->vcn < *update_from)
*update_from = rl->vcn;
/* skip entries fully used, if any */
while (rl->length && (rl->length < usedcnt)) {
usedcnt -= rl->length; /* must be > 0 */
rl++;
}
if (rl->length) {
/*
* Splitting the current allocation block requires
* an extra runlist element to create the hole.
* The required entry has been prereserved when
* mapping the runlist.
*/
/* get the free part in initial run */
freelcn = rl->lcn + usedcnt;
freevcn = rl->vcn + usedcnt;
/* new count of allocated clusters */
if (!((freevcn + freecnt)
& (na->compression_block_clusters - 1))) {
if (!appending)
res = ntfs_compress_overwr_free(na,rl,
usedcnt,freecnt,update_from);
else {
freelength = rl->length - usedcnt;
beginhole = !usedcnt && !rl->vcn;
mergeholes = !usedcnt
&& rl[0].vcn
&& (rl[-1].lcn == LCN_HOLE);
if (mergeholes) {
s32 carry;
/* shorten the runs which have free space */
carry = freecnt;
freerl = rl;
while (freerl->length < carry) {
carry -= freerl->length;
freerl++;
}
freerl->length = carry;
freerl = rl;
} else {
rl->length = usedcnt; /* can be zero ? */
freerl = ++rl;
}
if ((freelength > 0)
&& !mergeholes
&& (usedcnt || beginhole)) {
/*
* move the unused part to the end. Doing so,
* the vcn will be out of order. This does
* not harm, the vcn are meaningless now, and
* only the lcn are meaningful for freeing.
*/
/* locate current end */
while (rl->length)
rl++;
/* new terminator relocated */
rl[1].vcn = rl->vcn;
rl[1].lcn = LCN_ENOENT;
rl[1].length = 0;
/* hole, currently allocated */
rl->vcn = freevcn;
rl->lcn = freelcn;
rl->length = freelength;
} else {
/* why is this different from the begin hole case ? */
if ((freelength > 0)
&& !mergeholes
&& !usedcnt) {
freerl--;
freerl->length = freelength;
if (freerl->vcn < *update_from)
*update_from
= freerl->vcn;
}
}
/* free the hole */
res = ntfs_cluster_free_from_rl(vol,freerl);
if (!res) {
na->compressed_size -= freecnt
<< vol->cluster_size_bits;
if (mergeholes) {
/* merge with adjacent hole */
freerl--;
freerl->length += freecnt;
} else {
if (beginhole)
freerl--;
/* mark hole as free */
freerl->lcn = LCN_HOLE;
freerl->vcn = freevcn;
freerl->length = freecnt;
}
if (freerl->vcn < *update_from)
*update_from = freerl->vcn;
/* and set up the new end */
freerl[1].lcn = LCN_ENOENT;
freerl[1].vcn = freevcn + freecnt;
freerl[1].length = 0;
}
}
} else {
ntfs_log_error("Bad end of a compression block set\n");
errno = EIO;
}
} else {
ntfs_log_error("No cluster to free after compression\n");
errno = EIO;
}
return (res);
}
/*
* Read existing data, decompress and append buffer
* Do nothing if something fails
*/
static int ntfs_read_append(ntfs_attr *na, const runlist_element *rl,
s64 offs, u32 compsz, s32 pos, BOOL appending,
char *outbuf, s64 to_write, const void *b)
{
int fail = 1;
char *compbuf;
u32 decompsz;
u32 got;
if (compsz == na->compression_block_size) {
/* if the full block was requested, it was a hole */
memset(outbuf,0,compsz);
memcpy(&outbuf[pos],b,to_write);
fail = 0;
} else {
compbuf = (char*)ntfs_malloc(compsz);
if (compbuf) {
/* must align to full block for decompression */
if (appending)
decompsz = ((pos - 1) | (NTFS_SB_SIZE - 1)) + 1;
else
decompsz = na->compression_block_size;
got = read_clusters(na->ni->vol, rl, offs,
compsz, compbuf);
if ((got == compsz)
&& !ntfs_decompress((u8*)outbuf,decompsz,
(u8*)compbuf,compsz)) {
memcpy(&outbuf[pos],b,to_write);
fail = 0;
}
free(compbuf);
}
}
return (fail);
}
/*
* Flush a full compression block
*
* returns the size actually written (rounded to a full cluster)
* or 0 if could not compress (and written uncompressed)
* or -1 if there were an irrecoverable error (errno set)
*/
static int ntfs_flush(ntfs_attr *na, runlist_element *rl, s64 offs,
const char *outbuf, s32 count, BOOL compress,
BOOL appending, VCN *update_from)
{
int rounded;
int written;
int clsz;
if (compress) {
written = ntfs_comp_set(na, rl, offs, count, outbuf);
if (written == -1)
compress = FALSE;
if ((written >= 0)
&& ntfs_compress_free(na,rl,offs + written,
offs + na->compression_block_size, appending,
update_from))
written = -1;
} else
written = 0;
if (!compress) {
clsz = 1 << na->ni->vol->cluster_size_bits;
rounded = ((count - 1) | (clsz - 1)) + 1;
written = write_clusters(na->ni->vol, rl,
offs, rounded, outbuf);
if (written != rounded)
written = -1;
}
return (written);
}
/*
* Write some data to be compressed.
* Compression only occurs when a few clusters (usually 16) are
* full. When this occurs an extra runlist slot may be needed, so
* it has to be reserved beforehand.
*
* Returns the size of uncompressed data written,
* or negative if an error occurred.
* When the returned size is less than requested, new clusters have
* to be allocated before the function is called again.
*/
s64 ntfs_compressed_pwrite(ntfs_attr *na, runlist_element *wrl, s64 wpos,
s64 offs, s64 to_write, s64 rounded,
const void *b, int compressed_part,
VCN *update_from)
{
ntfs_volume *vol;
runlist_element *brl; /* entry containing the beginning of block */
int compression_length;
s64 written;
s64 to_read;
s64 to_flush;
s64 roffs;
s64 got;
s64 start_vcn;
s64 nextblock;
s64 endwrite;
u32 compsz;
char *inbuf;
char *outbuf;
BOOL fail;
BOOL done;
BOOL compress;
BOOL appending;
if (!valid_compressed_run(na,wrl,FALSE,"begin compressed write")) {
return (-1);
}
if ((*update_from < 0)
|| (compressed_part < 0)
|| (compressed_part > (int)na->compression_block_clusters)) {
ntfs_log_error("Bad update vcn or compressed_part %d for compressed write\n",
compressed_part);
errno = EIO;
return (-1);
}
/* make sure there are two unused entries in runlist */
if (na->unused_runs < 2) {
ntfs_log_error("No unused runs for compressed write\n");
errno = EIO;
return (-1);
}
if (wrl->vcn < *update_from)
*update_from = wrl->vcn;
written = -1; /* default return */
vol = na->ni->vol;
compression_length = na->compression_block_clusters;
compress = FALSE;
done = FALSE;
/*
* Cannot accept writing beyond the current compression set
* because when compression occurs, clusters are freed
* and have to be reallocated.
* (cannot happen with standard fuse 4K buffers)
* Caller has to avoid this situation, or face consequences.
*/
nextblock = ((offs + (wrl->vcn << vol->cluster_size_bits))
| (na->compression_block_size - 1)) + 1;
/* determine whether we are appending to file */
endwrite = offs + to_write + (wrl->vcn << vol->cluster_size_bits);
appending = endwrite >= na->initialized_size;
if (endwrite >= nextblock) {
/* it is time to compress */
compress = TRUE;
/* only process what we can */
to_write = rounded = nextblock
- (offs + (wrl->vcn << vol->cluster_size_bits));
}
start_vcn = 0;
fail = FALSE;
brl = wrl;
roffs = 0;
/*
* If we are about to compress or we need to decompress
* existing data, we have to process a full set of blocks.
* So relocate the parameters to the beginning of allocation
* containing the first byte of the set of blocks.
*/
if (compress || compressed_part) {
/* find the beginning of block */
start_vcn = (wrl->vcn + (offs >> vol->cluster_size_bits))
& -compression_length;
if (start_vcn < *update_from)
*update_from = start_vcn;
while (brl->vcn && (brl->vcn > start_vcn)) {
/* jumping back a hole means big trouble */
if (brl->lcn == (LCN)LCN_HOLE) {
ntfs_log_error("jump back over a hole when appending\n");
fail = TRUE;
errno = EIO;
}
brl--;
offs += brl->length << vol->cluster_size_bits;
}
roffs = (start_vcn - brl->vcn) << vol->cluster_size_bits;
}
if (compressed_part && !fail) {
/*
* The set of compression blocks contains compressed data
* (we are reopening an existing file to append to it)
* Decompress the data and append
*/
compsz = compressed_part << vol->cluster_size_bits;
outbuf = (char*)ntfs_malloc(na->compression_block_size);
if (outbuf) {
if (appending) {
to_read = offs - roffs;
to_flush = to_read + to_write;
} else {
to_read = na->data_size
- (brl->vcn << vol->cluster_size_bits);
if (to_read > na->compression_block_size)
to_read = na->compression_block_size;
to_flush = to_read;
}
if (!ntfs_read_append(na, brl, roffs, compsz,
(s32)(offs - roffs), appending,
outbuf, to_write, b)) {
written = ntfs_flush(na, brl, roffs,
outbuf, to_flush, compress, appending,
update_from);
if (written >= 0) {
written = to_write;
done = TRUE;
}
}
free(outbuf);
}
} else {
if (compress && !fail) {
/*
* we are filling up a block, read the full set
* of blocks and compress it
*/
inbuf = (char*)ntfs_malloc(na->compression_block_size);
if (inbuf) {
to_read = offs - roffs;
if (to_read)
got = read_clusters(vol, brl, roffs,
to_read, inbuf);
else
got = 0;
if (got == to_read) {
memcpy(&inbuf[to_read],b,to_write);
written = ntfs_comp_set(na, brl, roffs,
to_read + to_write, inbuf);
/*
* if compression was not successful,
* only write the part which was requested
*/
if ((written >= 0)
/* free the unused clusters */
&& !ntfs_compress_free(na,brl,
written + roffs,
na->compression_block_size
+ roffs,
appending, update_from)) {
done = TRUE;
written = to_write;
}
}
free(inbuf);
}
}
if (!done) {
/*
* if the compression block is not full, or
* if compression failed for whatever reason,
* write uncompressed
*/
/* check we are not overflowing current allocation */
if ((wpos + rounded)
> ((wrl->lcn + wrl->length)
<< vol->cluster_size_bits)) {
ntfs_log_error("writing on unallocated clusters\n");
errno = EIO;
} else {
written = ntfs_pwrite(vol->dev, wpos,
rounded, b);
if (written == rounded)
written = to_write;
}
}
}
if ((written >= 0)
&& !valid_compressed_run(na,wrl,TRUE,"end compressed write"))
written = -1;
return (written);
}
/*
* Close a file written compressed.
* This compresses the last partial compression block of the file.
* Two empty runlist slots have to be reserved beforehand.
*
* Returns zero if closing is successful.
*/
int ntfs_compressed_close(ntfs_attr *na, runlist_element *wrl, s64 offs,
VCN *update_from)
{
ntfs_volume *vol;
runlist_element *brl; /* entry containing the beginning of block */
int compression_length;
s64 written;
s64 to_read;
s64 roffs;
s64 got;
s64 start_vcn;
char *inbuf;
BOOL fail;
BOOL done;
if (na->unused_runs < 2) {
ntfs_log_error("No unused runs for compressed close\n");
errno = EIO;
return (-1);
}
if (*update_from < 0) {
ntfs_log_error("Bad update vcn for compressed close\n");
errno = EIO;
return (-1);
}
if (wrl->vcn < *update_from)
*update_from = wrl->vcn;
vol = na->ni->vol;
compression_length = na->compression_block_clusters;
done = FALSE;
/*
* There generally is an uncompressed block at end of file,
* read the full block and compress it
*/
inbuf = (char*)ntfs_malloc(na->compression_block_size);
if (inbuf) {
start_vcn = (wrl->vcn + (offs >> vol->cluster_size_bits))
& -compression_length;
if (start_vcn < *update_from)
*update_from = start_vcn;
to_read = offs + ((wrl->vcn - start_vcn)
<< vol->cluster_size_bits);
brl = wrl;
fail = FALSE;
while (brl->vcn && (brl->vcn > start_vcn)) {
if (brl->lcn == (LCN)LCN_HOLE) {
ntfs_log_error("jump back over a hole when closing\n");
fail = TRUE;
errno = EIO;
}
brl--;
}
if (!fail) {
/* roffs can be an offset from another uncomp block */
roffs = (start_vcn - brl->vcn)
<< vol->cluster_size_bits;
if (to_read) {
got = read_clusters(vol, brl, roffs, to_read,
inbuf);
if (got == to_read) {
written = ntfs_comp_set(na, brl, roffs,
to_read, inbuf);
if ((written >= 0)
/* free the unused clusters */
&& !ntfs_compress_free(na,brl,
written + roffs,
na->compression_block_size + roffs,
TRUE, update_from)) {
done = TRUE;
} else
/* if compression failed, leave uncompressed */
if (written == -1)
done = TRUE;
}
} else
done = TRUE;
free(inbuf);
}
}
if (done && !valid_compressed_run(na,wrl,TRUE,"end compressed close"))
done = FALSE;
return (!done);
}
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