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/*
* attr.c
*
* Copyright (C) 1996-1999 Martin von Löwis
* Copyright (C) 1996-1997 Régis Duchesne
* Copyright (C) 1998 Joseph Malicki
* Copyright (C) 1999 Steve Dodd
* Copyright (C) 2001 Anton Altaparmakov (AIA)
*/
#include "ntfstypes.h"
#include "struct.h"
#include "attr.h"
#include <linux/errno.h>
#include <linux/ntfs_fs.h>
#include "macros.h"
#include "support.h"
#include "util.h"
#include "super.h"
#include "inode.h"
#include "unistr.h"
/**
* ntfs_find_attr_in_mft_rec - find attribute in mft record
* @vol: volume on which attr resides
* @m: mft record to search
* @type: attribute type to find
* @name: attribute name to find (optional, i.e. NULL means don't care)
* @name_len: attribute name length (only needed if @name present)
* @ic: ignore case if 1 or case sensitive if 0 (ignored if @name NULL)
* @instance: instance number to find
*
* Only search the specified mft record and it ignores the presence of an
* attribute list attribute (unless it is the one being searched for,
* obviously, in which case it is returned).
*/
ntfs_u8* ntfs_find_attr_in_mft_rec(ntfs_volume *vol, ntfs_u8 *m, __u32 type,
wchar_t *name, __u32 name_len, int ic, __u16 instance)
{
ntfs_u8 *a;
/* Iterate over attributes in mft record @m. */
a = m + NTFS_GETU16(m + 20); /* attrs_offset */
for (; a >= m && a <= m + vol->mft_record_size;
a += NTFS_GETU32(a + 4 /* length */)) {
/* We catch $END with this more general check, too... */
if (NTFS_GETU32(a + 0 /* type */) > type)
return NULL;
if (!NTFS_GETU32(a + 4 /* length */))
break;
if (NTFS_GETU32(a + 0 /* type */) != type)
continue;
/* If @name is present, compare the two names. */
if (name && !ntfs_are_names_equal(name, name_len, (wchar_t*)
(a + NTFS_GETU16(a + 10 /* name_offset */)),
a[9] /* name_length */, ic, vol->upcase,
vol->upcase_length)) {
register int rc;
rc = ntfs_collate_names(vol->upcase, vol->upcase_length,
name, name_len, (wchar_t*)(a +
NTFS_GETU16(a + 10 /* name_offset */)),
a[9] /* name_length */, 1, 1);
/*
* If @name collates before a->name, there is no
* matching attribute.
*/
if (rc == -1)
return NULL;
/* If the strings are not equal, continue search. */
if (rc)
continue;
rc = ntfs_collate_names(vol->upcase, vol->upcase_length,
name, name_len, (wchar_t*)(a +
NTFS_GETU16(a + 10 /* name_offset */)),
a[9] /* name_length */, 0, 1);
if (rc == -1)
return NULL;
if (rc)
continue;
}
/*
* The names match or @name not present. Check instance number.
* and if it matches we have found the attribute and are done.
*/
if (instance != NTFS_GETU16(a + 14 /* instance */))
continue;
ntfs_debug(DEBUG_FILE3, "ntfs_find_attr_in_mft_record: found: "
"attr type 0x%x, instance number = 0x%x.\n",
NTFS_GETU32(a + 0), instance);
return a;
}
ntfs_error("ntfs_find_attr_in_mft_record: mft record 0x%x is corrupt"
". Run chkdsk.\n", m);
return NULL;
}
/* Look if an attribute already exists in the inode, and if not, create it. */
int ntfs_new_attr(ntfs_inode *ino, int type, void *name, int namelen,
void *value, int value_len, int *pos, int *found)
{
int do_insert = 0;
int i, m;
ntfs_attribute *a;
for (i = 0; i < ino->attr_count; i++)
{
a = ino->attrs + i;
if (a->type < type)
continue;
if (a->type > type) {
do_insert = 1;
break;
}
/* If @name is present, compare the two names. */
if (namelen && !ntfs_are_names_equal((wchar_t*)name, namelen,
a->name, a->namelen /* name_length */,
1 /* ignore case*/, ino->vol->upcase,
ino->vol->upcase_length)) {
register int rc;
rc = ntfs_collate_names(ino->vol->upcase,
ino->vol->upcase_length, a->name,
a->namelen, (wchar_t*)name, namelen,
1 /* ignore case */, 1);
if (rc == -1)
continue;
if (rc == 1) {
do_insert = 1;
break;
}
rc = ntfs_collate_names(ino->vol->upcase,
ino->vol->upcase_length, a->name,
a->namelen, (wchar_t*)name, namelen,
0 /* case sensitive */, 1);
if (rc == -1)
continue;
if (rc == 1) {
do_insert = 1;
break;
}
}
/* Names are equal or no name was asked for. */
/* If a value was specified compare the values. */
if (value_len && a->resident) {
if (!a->resident) {
ntfs_error("ntfs_new_attr: Value specified but "
"attribute non-resident. Bug!\n");
return -EINVAL;
}
m = value_len;
if (m > a->size)
m = a->size;
m = memcmp(value, a->d.data, m);
if (m > 0)
continue;
if (m < 0) {
do_insert = 1;
break;
}
/* Values match until min of value lengths. */
if (value_len > a->size)
continue;
if (value_len < a->size) {
do_insert = 1;
break;
}
}
/* Full match! */
*found = 1;
*pos = i;
return 0;
}
/* Re-allocate space. */
if (ino->attr_count % 8 == 0)
{
ntfs_attribute* new;
new = (ntfs_attribute*)ntfs_malloc((ino->attr_count + 8) *
sizeof(ntfs_attribute));
if (!new)
return -ENOMEM;
if (ino->attrs) {
ntfs_memcpy(new, ino->attrs, ino->attr_count *
sizeof(ntfs_attribute));
ntfs_free(ino->attrs);
}
ino->attrs = new;
}
if (do_insert)
ntfs_memmove(ino->attrs + i + 1, ino->attrs + i,
(ino->attr_count - i) * sizeof(ntfs_attribute));
ino->attr_count++;
ino->attrs[i].type = type;
ino->attrs[i].namelen = namelen;
ino->attrs[i].name = name;
*pos = i;
*found = 0;
return 0;
}
int ntfs_make_attr_resident(ntfs_inode *ino, ntfs_attribute *attr)
{
__s64 size = attr->size;
if (size > 0) {
/* FIXME: read data, free clusters */
return -EOPNOTSUPP;
}
attr->resident = 1;
return 0;
}
/* Store in the inode readable information about a run. */
int ntfs_insert_run(ntfs_attribute *attr, int cnum, ntfs_cluster_t cluster,
int len)
{
/* (re-)allocate space if necessary. */
if ((attr->d.r.len * sizeof(ntfs_runlist)) % PAGE_SIZE == 0) {
ntfs_runlist* new;
unsigned long new_size;
ntfs_debug(DEBUG_MALLOC, "ntfs_insert_run: re-allocating "
"space: old attr->d.r.len = 0x%x\n",
attr->d.r.len);
new_size = attr->d.r.len * sizeof(ntfs_runlist) + PAGE_SIZE;
if ((new_size >> PAGE_SHIFT) > num_physpages) {
ntfs_error("ntfs_insert_run: attempted to allocate "
"more pages than num_physpages."
"This might be a bug or a corrupt"
"file system.\n");
return -1;
}
new = ntfs_vmalloc(new_size);
if (!new) {
ntfs_error("ntfs_insert_run: ntfs_vmalloc(new_size = "
"0x%x) failed\n", new_size);
return -1;
}
if (attr->d.r.runlist) {
ntfs_memcpy(new, attr->d.r.runlist, attr->d.r.len
* sizeof(ntfs_runlist));
ntfs_vfree(attr->d.r.runlist);
}
attr->d.r.runlist = new;
}
if (attr->d.r.len > cnum)
ntfs_memmove(attr->d.r.runlist + cnum + 1,
attr->d.r.runlist + cnum,
(attr->d.r.len - cnum) * sizeof(ntfs_runlist));
attr->d.r.runlist[cnum].lcn = cluster;
attr->d.r.runlist[cnum].len = len;
attr->d.r.len++;
return 0;
}
/**
* ntfs_extend_attr - extend allocated size of an attribute
* @ino: ntfs inode containing the attribute to extend
* @attr: attribute which to extend
* @len: desired new length for @attr (_not_ the amount to extend by)
*
* Extends an attribute. Allocate clusters on the volume which @ino belongs to.
* Extends the run list accordingly, preferably by extending the last run of
* the existing run list, first.
*
* Only modifies attr->allocated, i.e. doesn't touch attr->size, nor
* attr->initialized.
*/
int ntfs_extend_attr(ntfs_inode *ino, ntfs_attribute *attr, const __s64 len)
{
int rlen, rl2_len, err = 0;
ntfs_cluster_t cluster, clen;
ntfs_runlist *rl, *rl2;
if ((attr->flags & (ATTR_IS_COMPRESSED | ATTR_IS_ENCRYPTED)) ||
ino->record_count > 1)
return -EOPNOTSUPP;
/*
* FIXME: Don't make non-resident if the attribute type is not right.
* For example cannot make index attribute non-resident! (AIA)
*/
if (attr->resident) {
err = ntfs_make_attr_nonresident(ino, attr);
if (err)
return err;
}
if (len <= attr->allocated)
return 0; /* Truly stupid things do sometimes happen. */
rl = attr->d.r.runlist;
rlen = attr->d.r.len;
if (rlen > 0)
cluster = rl[rlen - 1].lcn + rl[rlen - 1].len;
else
/* No preference for allocation space. */
cluster = (ntfs_cluster_t)-1;
/*
* Calculate the extra space we need, and round up to multiple of
* cluster size to get number of new clusters needed.
*/
clen = (len - attr->allocated + ino->vol->cluster_size - 1) >>
ino->vol->cluster_size_bits;
if (!clen)
return 0;
err = ntfs_allocate_clusters(ino->vol, &cluster, &clen, &rl2,
&rl2_len, DATA_ZONE);
if (err)
return err;
attr->allocated += (__s64)clen << ino->vol->cluster_size_bits;
if (rlen > 0) {
err = splice_runlists(&rl, &rlen, rl2, rl2_len);
ntfs_vfree(rl2);
if (err)
return err;
} else {
if (rl)
ntfs_vfree(rl);
rl = rl2;
rlen = rl2_len;
}
attr->d.r.runlist = rl;
attr->d.r.len = rlen;
return 0;
}
int ntfs_make_attr_nonresident(ntfs_inode *ino, ntfs_attribute *attr)
{
int error;
ntfs_io io;
void *data = attr->d.data;
__s64 len = attr->size;
attr->d.r.len = 0;
attr->d.r.runlist = NULL;
attr->resident = 0;
/*
* ->allocated is updated by ntfs_extend_attr(), while ->initialized
* and ->size are updated by ntfs_readwrite_attr(). (AIA)
*/
attr->allocated = attr->initialized = 0;
error = ntfs_extend_attr(ino, attr, len);
if (error)
return error; /* FIXME: On error, restore old values. */
io.fn_put = ntfs_put;
io.fn_get = ntfs_get;
io.param = data;
io.size = len;
io.do_read = 0;
return ntfs_readwrite_attr(ino, attr, 0, &io);
}
int ntfs_attr_allnonresident(ntfs_inode *ino)
{
int i, error = 0;
ntfs_volume *vol = ino->vol;
for (i = 0; !error && i < ino->attr_count; i++)
{
if (ino->attrs[i].type != vol->at_security_descriptor &&
ino->attrs[i].type != vol->at_data)
continue;
error = ntfs_make_attr_nonresident(ino, ino->attrs + i);
}
return error;
}
/*
* Resize the attribute to a newsize. attr->allocated and attr->size are
* updated, but attr->initialized is not changed unless it becomes bigger than
* attr->size, in which case it is set to attr->size.
*/
int ntfs_resize_attr(ntfs_inode *ino, ntfs_attribute *attr, __s64 newsize)
{
int error = 0;
__s64 oldsize = attr->size;
int clustersizebits = ino->vol->cluster_size_bits;
int i, count, newcount;
ntfs_runlist *rl, *rlt;
if (newsize == oldsize)
return 0;
if (attr->flags & (ATTR_IS_COMPRESSED | ATTR_IS_ENCRYPTED))
return -EOPNOTSUPP;
if (attr->resident) {
void *v;
if (newsize > ino->vol->mft_record_size) {
error = ntfs_make_attr_nonresident(ino, attr);
if (error)
return error;
return ntfs_resize_attr(ino, attr, newsize);
}
v = attr->d.data;
if (newsize) {
__s64 minsize = newsize;
attr->d.data = ntfs_malloc(newsize);
if (!attr->d.data) {
ntfs_free(v);
return -ENOMEM;
}
if (newsize > oldsize) {
minsize = oldsize;
ntfs_bzero((char*)attr->d.data + oldsize,
newsize - oldsize);
}
ntfs_memcpy((char*)attr->d.data, v, minsize);
} else
attr->d.data = 0;
ntfs_free(v);
attr->size = newsize;
return 0;
}
/* Non-resident attribute. */
rl = attr->d.r.runlist;
if (newsize < oldsize) {
int rl_size;
/*
* FIXME: We might be going awfully wrong for newsize = 0,
* possibly even leaking memory really badly. But considering
* in that case there is more breakage due to -EOPNOTSUPP stuff
* further down the code path, who cares for the moment... (AIA)
*/
for (i = 0, count = 0; i < attr->d.r.len; i++) {
if ((__s64)(count + rl[i].len) << clustersizebits >
newsize) {
i++;
break;
}
count += (int)rl[i].len;
}
newcount = count;
/* Free unused clusters in current run, unless sparse. */
if (rl[--i].lcn != (ntfs_cluster_t)-1) {
ntfs_cluster_t rounded = newsize - ((__s64)count <<
clustersizebits);
rounded = (rounded + ino->vol->cluster_size - 1) >>
clustersizebits;
error = ntfs_deallocate_cluster_run(ino->vol,
rl[i].lcn + rounded,
rl[i].len - rounded);
if (error)
return error; /* FIXME: Incomplete operation. */
rl[i].len = rounded;
newcount = count + rounded;
}
/* Free all other runs. */
i++;
error = ntfs_deallocate_clusters(ino->vol, rl + i,
attr->d.r.len - i);
if (error)
return error; /* FIXME: Incomplete operation. */
/*
* Free space for extra runs in memory if enough memory left
* to do so. FIXME: Only do it if it would free memory. (AIA)
*/
rl_size = ((i + 1) * sizeof(ntfs_runlist) + PAGE_SIZE - 1) &
PAGE_MASK;
if (rl_size < ((attr->d.r.len * sizeof(ntfs_runlist) +
PAGE_SIZE - 1) & PAGE_MASK)) {
rlt = ntfs_vmalloc(rl_size);
if (rlt) {
ntfs_memcpy(rlt, rl, i * sizeof(ntfs_runlist));
ntfs_vfree(rl);
attr->d.r.runlist = rl = rlt;
}
}
rl[i].lcn = (ntfs_cluster_t)-1;
rl[i].len = (ntfs_cluster_t)0;
attr->d.r.len = i;
} else {
error = ntfs_extend_attr(ino, attr, newsize);
if (error)
return error; /* FIXME: Incomplete operation. */
newcount = (newsize + ino->vol->cluster_size - 1) >>
clustersizebits;
}
/* Fill in new sizes. */
attr->allocated = (__s64)newcount << clustersizebits;
attr->size = newsize;
if (attr->initialized > newsize)
attr->initialized = newsize;
if (!newsize)
error = ntfs_make_attr_resident(ino, attr);
return error;
}
int ntfs_create_attr(ntfs_inode *ino, int anum, char *aname, void *data,
int dsize, ntfs_attribute **rattr)
{
void *name;
int namelen;
int found, i;
int error;
ntfs_attribute *attr;
if (dsize > ino->vol->mft_record_size)
/* FIXME: Non-resident attributes. */
return -EOPNOTSUPP;
if (aname) {
namelen = strlen(aname);
name = ntfs_malloc(2 * namelen);
if (!name)
return -ENOMEM;
ntfs_ascii2uni(name, aname, namelen);
} else {
name = 0;
namelen = 0;
}
error = ntfs_new_attr(ino, anum, name, namelen, data, dsize, &i,
&found);
if (error || found) {
ntfs_free(name);
return error ? error : -EEXIST;
}
*rattr = attr = ino->attrs + i;
/* Allocate a new number.
* FIXME: Should this happen on inode writeback?
* FIXME: Extension records not supported. */
error = ntfs_allocate_attr_number(ino, &i);
if (error)
return error;
attr->attrno = i;
if (attr->attrno + 1 != NTFS_GETU16(ino->attr + 0x28))
ntfs_error("UH OH! attr->attrno (%i) != NTFS_GETU16(ino->attr "
"+ 0x28) (%i)\n", attr->attrno,
NTFS_GETU16(ino->attr + 0x28));
attr->resident = 1;
attr->flags = 0;
attr->cengine = 0;
attr->size = attr->allocated = attr->initialized = dsize;
/* FIXME: INDEXED information should come from $AttrDef
* Currently, only file names are indexed. As of NTFS v3.0 (Win2k),
* this is no longer true. Different attributes can be indexed now. */
if (anum == ino->vol->at_file_name)
attr->indexed = 1;
else
attr->indexed = 0;
attr->d.data = ntfs_malloc(dsize);
if (!attr->d.data)
return -ENOMEM;
ntfs_memcpy(attr->d.data, data, dsize);
return 0;
}
/*
* Non-resident attributes are stored in runs (intervals of clusters).
*
* This function stores in the inode readable information about a non-resident
* attribute.
*/
static int ntfs_process_runs(ntfs_inode *ino, ntfs_attribute* attr,
unsigned char *data)
{
int startvcn, endvcn;
int vcn, cnum;
ntfs_cluster_t cluster;
int len, ctype;
int er = 0;
startvcn = NTFS_GETS64(data + 0x10);
endvcn = NTFS_GETS64(data + 0x18);
/* Check whether this chunk really belongs to the end. Problem with
* this: this functions can get called on the last extent first, before
* it is called on the other extents in sequence. This happens when the
* base mft record contains the last extent instead of the first one
* and the first extent is stored, like any intermediate extents in
* extension mft records. This would be difficult to allow the way the
* runlist is stored in memory. Thus we fix elsewhere by causing the
* attribute list attribute to be processed immediately when found. The
* extents will then be processed starting with the first one. */
for (cnum = 0, vcn = 0; cnum < attr->d.r.len; cnum++)
vcn += attr->d.r.runlist[cnum].len;
if (vcn != startvcn) {
ntfs_debug(DEBUG_FILE3, "ntfs_process_runs: ino = 0x%x, "
"attr->type = 0x%x, startvcn = 0x%x, endvcn = 0x%x, "
"vcn = 0x%x, cnum = 0x%x\n", ino->i_number, attr->type,
startvcn, endvcn, vcn, cnum);
if (vcn < startvcn) {
ntfs_error("Problem with runlist in extended record\n");
return -1;
}
/* Tried to insert an already inserted runlist. */
return 0;
}
if (!endvcn) {
if (!startvcn) {
/* Allocated length. */
endvcn = NTFS_GETS64(data + 0x28) - 1;
endvcn >>= ino->vol->cluster_size_bits;
} else {
/* This is an extent. Allocated length is not defined!
* Extents must have an endvcn though so this is an
* error. */
ntfs_error("Corrupt attribute extent. (endvcn is "
"missing)\n");
return -1;
}
}
data = data + NTFS_GETU16(data + 0x20);
cnum = attr->d.r.len;
cluster = 0;
for (vcn = startvcn; vcn <= endvcn; vcn += len) {
if (ntfs_decompress_run(&data, &len, &cluster, &ctype)) {
ntfs_debug(DEBUG_FILE3, "ntfs_process_runs: "
"ntfs_decompress_run failed. i_number = 0x%x\n",
ino->i_number);
return -1;
}
if (ctype)
er = ntfs_insert_run(attr, cnum, -1, len);
else
er = ntfs_insert_run(attr, cnum, cluster, len);
if (er)
break;
cnum++;
}
if (er)
ntfs_error("ntfs_process_runs: ntfs_insert_run failed\n");
ntfs_debug(DEBUG_FILE3, "ntfs_process_runs: startvcn = 0x%x, vcn = 0x%x"
", endvcn = 0x%x, cnum = %i\n", startvcn, vcn,
endvcn, cnum);
return er;
}
/* Insert the attribute starting at attr in the inode ino. */
int ntfs_insert_attribute(ntfs_inode *ino, unsigned char *attrdata)
{
int i, found;
int type;
short int *name;
int namelen;
void *data;
ntfs_attribute *attr;
int error;
type = NTFS_GETU32(attrdata);
namelen = NTFS_GETU8(attrdata + 9);
ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute: ino->i_number 0x%x, "
"attr type 0x%x\n", ino->i_number, type);
/* Read the attribute's name if it has one. */
if (!namelen)
name = 0;
else {
/* 1 Unicode character fits in 2 bytes. */
name = ntfs_malloc(2 * namelen);
if (!name)
return -ENOMEM;
ntfs_memcpy(name, attrdata + NTFS_GETU16(attrdata + 10),
2 * namelen);
}
/* If resident look for value, too. */
if (NTFS_GETU8(attrdata + 8) == 0)
error = ntfs_new_attr(ino, type, name, namelen,
attrdata + NTFS_GETU16(attrdata + 0x14),
NTFS_GETU16(attrdata + 0x10), &i, &found);
else
error = ntfs_new_attr(ino, type, name, namelen, NULL, 0, &i,
&found);
if (error) {
ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute: ntfs_new_attr "
"failed.\n");
if (name)
ntfs_free(name);
return error;
}
if (found) {
/* It's already there, if not resident just process the runs. */
if (!ino->attrs[i].resident) {
ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute:"
" processing runs 1.\n");
/* FIXME: Check error code! (AIA) */
ntfs_process_runs(ino, ino->attrs + i, attrdata);
}
return 0;
}
attr = ino->attrs + i;
attr->resident = NTFS_GETU8(attrdata + 8) == 0;
attr->flags = *(__u16*)(attrdata + 0xC);
attr->attrno = NTFS_GETU16(attrdata + 0xE);
if (attr->resident) {
attr->size = NTFS_GETU16(attrdata + 0x10);
data = attrdata + NTFS_GETU16(attrdata + 0x14);
attr->d.data = (void*)ntfs_malloc(attr->size);
if (!attr->d.data)
return -ENOMEM;
ntfs_memcpy(attr->d.data, data, attr->size);
attr->indexed = NTFS_GETU8(attrdata + 0x16);
} else {
attr->allocated = NTFS_GETS64(attrdata + 0x28);
attr->size = NTFS_GETS64(attrdata + 0x30);
attr->initialized = NTFS_GETS64(attrdata + 0x38);
attr->cengine = NTFS_GETU16(attrdata + 0x22);
if (attr->flags & ATTR_IS_COMPRESSED)
attr->compsize = NTFS_GETS64(attrdata + 0x40);
ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute: "
"attr->allocated = 0x%Lx, attr->size = 0x%Lx, "
"attr->initialized = 0x%Lx\n", attr->allocated,
attr->size, attr->initialized);
ino->attrs[i].d.r.runlist = 0;
ino->attrs[i].d.r.len = 0;
ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute: processing "
"runs 2.\n");
/* FIXME: Check error code! (AIA) */
ntfs_process_runs(ino, attr, attrdata);
}
return 0;
}
int ntfs_read_zero(ntfs_io *dest, int size)
{
int i;
char *sparse = ntfs_calloc(512);
if (!sparse)
return -ENOMEM;
i = 512;
while (size) {
if (i > size)
i = size;
dest->fn_put(dest, sparse, i);
size -= i;
}
ntfs_free(sparse);
return 0;
}
/* Process compressed attributes. */
int ntfs_read_compressed(ntfs_inode *ino, ntfs_attribute *attr, __s64 offset,
ntfs_io *dest)
{
int error = 0;
int clustersizebits;
int s_vcn, rnum, vcn, got, l1;
__s64 copied, len, chunk, offs1, l, chunk2;
ntfs_cluster_t cluster, cl1;
char *comp = 0, *comp1;
char *decomp = 0;
ntfs_io io;
ntfs_runlist *rl;
l = dest->size;
clustersizebits = ino->vol->cluster_size_bits;
/* Starting cluster of potential chunk. There are three situations:
a) In a large uncompressible or sparse chunk, s_vcn is in the middle
of a run.
b) s_vcn is right on a run border.
c) When several runs make a chunk, s_vcn is before the chunks. */
s_vcn = offset >> clustersizebits;
/* Round down to multiple of 16. */
s_vcn &= ~15;
rl = attr->d.r.runlist;
for (rnum = vcn = 0; rnum < attr->d.r.len && vcn + rl->len <= s_vcn;
rnum++, rl++)
vcn += rl->len;
if (rnum == attr->d.r.len) {
/* Beyond end of file. */
/* FIXME: Check allocated / initialized. */
dest->size = 0;
return 0;
}
io.do_read = 1;
io.fn_put = ntfs_put;
io.fn_get = 0;
cluster = rl->lcn;
len = rl->len;
copied = 0;
while (l) {
chunk = 0;
if (cluster == (ntfs_cluster_t)-1) {
/* Sparse cluster. */
__s64 ll;
if ((len - (s_vcn - vcn)) & 15)
ntfs_error("Unexpected sparse chunk size.");
ll = ((__s64)(vcn + len) << clustersizebits) - offset;
if (ll > l)
ll = l;
chunk = ll;
error = ntfs_read_zero(dest, ll);
if (error)
goto out;
} else if (dest->do_read) {
if (!comp) {
comp = ntfs_malloc(16 << clustersizebits);
if (!comp) {
error = -ENOMEM;
goto out;
}
}
got = 0;
/* We might need to start in the middle of a run. */
cl1 = cluster + s_vcn - vcn;
comp1 = comp;
do {
int delta;
io.param = comp1;
delta = s_vcn - vcn;
if (delta < 0)
delta = 0;
l1 = len - delta;
if (l1 > 16 - got)
l1 = 16 - got;
io.size = (__s64)l1 << clustersizebits;
error = ntfs_getput_clusters(ino->vol, cl1, 0,
&io);
if (error)
goto out;
if (l1 + delta == len) {
rnum++;
rl++;
vcn += len;
cluster = cl1 = rl->lcn;
len = rl->len;
}
got += l1;
comp1 += (__s64)l1 << clustersizebits;
} while (cluster != (ntfs_cluster_t)-1 && got < 16);
/* Until empty run. */
chunk = 16 << clustersizebits;
if (cluster != (ntfs_cluster_t)-1 || got == 16)
/* Uncompressible */
comp1 = comp;
else {
if (!decomp) {
decomp = ntfs_malloc(16 <<
clustersizebits);
if (!decomp) {
error = -ENOMEM;
goto out;
}
}
/* Make sure there are null bytes after the
* last block. */
*(ntfs_u32*)comp1 = 0;
ntfs_decompress(decomp, comp, chunk);
comp1 = decomp;
}
offs1 = offset - ((__s64)s_vcn << clustersizebits);
chunk2 = (16 << clustersizebits) - offs1;
if (chunk2 > l)
chunk2 = l;
if (chunk > chunk2)
chunk = chunk2;
dest->fn_put(dest, comp1 + offs1, chunk);
}
l -= chunk;
copied += chunk;
offset += chunk;
s_vcn = (offset >> clustersizebits) & ~15;
if (l && offset >= ((__s64)(vcn + len) << clustersizebits)) {
rnum++;
rl++;
vcn += len;
cluster = rl->lcn;
len = rl->len;
}
}
out:
if (comp)
ntfs_free(comp);
if (decomp)
ntfs_free(decomp);
dest->size = copied;
return error;
}
int ntfs_write_compressed(ntfs_inode *ino, ntfs_attribute *attr, __s64 offset,
ntfs_io *dest)
{
return -EOPNOTSUPP;
}
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