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/*
* super.c
*
* Copyright (C) 1995-1997, 1999 Martin von Löwis
* Copyright (C) 1996-1997 Régis Duchesne
* Copyright (C) 1999 Steve Dodd
* Copyright (C) 2000-2001 Anton Altparmakov (AIA)
*/
#include <linux/ntfs_fs.h>
#include <linux/errno.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include "ntfstypes.h"
#include "struct.h"
#include "super.h"
#include "macros.h"
#include "inode.h"
#include "support.h"
#include "util.h"
#include <linux/smp_lock.h>
/* All important structures in NTFS use 2 consistency checks:
* . a magic structure identifier (FILE, INDX, RSTR, RCRD...)
* . a fixup technique : the last word of each sector (called a fixup) of a
* structure's record should end with the word at offset <n> of the first
* sector, and if it is the case, must be replaced with the words following
* <n>. The value of <n> and the number of fixups is taken from the fields
* at the offsets 4 and 6. Note that the sector size is defined as
* NTFS_SECTOR_SIZE and not as the hardware sector size (this is concordant
* with what the Windows NTFS driver does).
*
* This function performs these 2 checks, and _fails_ if:
* . the input size is invalid
* . the fixup header is invalid
* . the size does not match the number of sectors
* . the magic identifier is wrong
* . a fixup is invalid
*/
int ntfs_fixup_record(char *record, char *magic, int size)
{
int start, count, offset;
ntfs_u16 fixup;
if (!IS_MAGIC(record, magic))
return 0;
start = NTFS_GETU16(record + 4);
count = NTFS_GETU16(record + 6) - 1;
if (size & (NTFS_SECTOR_SIZE - 1) || start & 1 ||
start + count * 2 > size || size >> 9 != count) {
if (size <= 0)
printk(KERN_ERR "NTFS: BUG: ntfs_fixup_record() got "
"zero size! Please report this to "
"linux-ntfs-dev@lists.sf.net\n");
return 0;
}
fixup = NTFS_GETU16(record + start);
start += 2;
offset = NTFS_SECTOR_SIZE - 2;
while (count--) {
if (NTFS_GETU16(record + offset) != fixup)
return 0;
NTFS_PUTU16(record + offset, NTFS_GETU16(record + start));
start += 2;
offset += NTFS_SECTOR_SIZE;
}
return 1;
}
/*
* Get vital informations about the ntfs partition from the boot sector.
* Return 0 on success or -1 on error.
*/
int ntfs_init_volume(ntfs_volume *vol, char *boot)
{
int sectors_per_cluster_bits;
__s64 ll;
ntfs_cluster_t mft_zone_size, tc;
/* System defined default values, in case we don't load $AttrDef. */
vol->at_standard_information = 0x10;
vol->at_attribute_list = 0x20;
vol->at_file_name = 0x30;
vol->at_volume_version = 0x40;
vol->at_security_descriptor = 0x50;
vol->at_volume_name = 0x60;
vol->at_volume_information = 0x70;
vol->at_data = 0x80;
vol->at_index_root = 0x90;
vol->at_index_allocation = 0xA0;
vol->at_bitmap = 0xB0;
vol->at_symlink = 0xC0;
/* Sector size. */
vol->sector_size = NTFS_GETU16(boot + 0xB);
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->sector_size = 0x%x\n",
vol->sector_size);
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: sectors_per_cluster = "
"0x%x\n", NTFS_GETU8(boot + 0xD));
sectors_per_cluster_bits = ffs(NTFS_GETU8(boot + 0xD)) - 1;
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: sectors_per_cluster_bits "
"= 0x%x\n", sectors_per_cluster_bits);
vol->mft_clusters_per_record = NTFS_GETS8(boot + 0x40);
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->mft_clusters_per_record"
" = 0x%x\n", vol->mft_clusters_per_record);
vol->index_clusters_per_record = NTFS_GETS8(boot + 0x44);
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: "
"vol->index_clusters_per_record = 0x%x\n",
vol->index_clusters_per_record);
vol->cluster_size = vol->sector_size << sectors_per_cluster_bits;
vol->cluster_size_bits = ffs(vol->cluster_size) - 1;
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->cluster_size = 0x%x\n",
vol->cluster_size);
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->cluster_size_bits = "
"0x%x\n", vol->cluster_size_bits);
if (vol->mft_clusters_per_record > 0)
vol->mft_record_size = vol->cluster_size <<
(ffs(vol->mft_clusters_per_record) - 1);
else
/*
* When mft_record_size < cluster_size, mft_clusters_per_record
* = -log2(mft_record_size) bytes. mft_record_size normaly is
* 1024 bytes, which is encoded as 0xF6 (-10 in decimal).
*/
vol->mft_record_size = 1 << -vol->mft_clusters_per_record;
vol->mft_record_size_bits = ffs(vol->mft_record_size) - 1;
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->mft_record_size = 0x%x"
"\n", vol->mft_record_size);
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->mft_record_size_bits = "
"0x%x\n", vol->mft_record_size_bits);
if (vol->index_clusters_per_record > 0)
vol->index_record_size = vol->cluster_size <<
(ffs(vol->index_clusters_per_record) - 1);
else
/*
* When index_record_size < cluster_size,
* index_clusters_per_record = -log2(index_record_size) bytes.
* index_record_size normaly equals 4096 bytes, which is
* encoded as 0xF4 (-12 in decimal).
*/
vol->index_record_size = 1 << -vol->index_clusters_per_record;
vol->index_record_size_bits = ffs(vol->index_record_size) - 1;
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->index_record_size = "
"0x%x\n", vol->index_record_size);
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->index_record_size_bits "
"= 0x%x\n", vol->index_record_size_bits);
/*
* Get the size of the volume in clusters (ofs 0x28 is nr_sectors) and
* check for 64-bit-ness. Windows currently only uses 32 bits to save
* the clusters so we do the same as it is much faster on 32-bit CPUs.
*/
ll = NTFS_GETS64(boot + 0x28) >> sectors_per_cluster_bits;
if (ll >= (__s64)1 << 31) {
ntfs_error("Cannot handle 64-bit clusters. Please inform "
"linux-ntfs-dev@lists.sf.net that you got this "
"error.\n");
return -1;
}
vol->nr_clusters = (ntfs_cluster_t)ll;
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->nr_clusters = 0x%x\n",
vol->nr_clusters);
vol->mft_lcn = (ntfs_cluster_t)NTFS_GETS64(boot + 0x30);
vol->mft_mirr_lcn = (ntfs_cluster_t)NTFS_GETS64(boot + 0x38);
/* Determine MFT zone size. */
mft_zone_size = vol->nr_clusters;
switch (vol->mft_zone_multiplier) { /* % of volume size in clusters */
case 4:
mft_zone_size >>= 1; /* 50% */
break;
case 3:
mft_zone_size = mft_zone_size * 3 >> 3; /* 37.5% */
break;
case 2:
mft_zone_size >>= 2; /* 25% */
break;
/* case 1: */
default:
mft_zone_size >>= 3; /* 12.5% */
break;
}
/* Setup mft zone. */
vol->mft_zone_start = vol->mft_zone_pos = vol->mft_lcn;
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->mft_zone_pos = %x\n",
vol->mft_zone_pos);
/*
* Calculate the mft_lcn for an unmodified NTFS volume (see mkntfs
* source) and if the actual mft_lcn is in the expected place or even
* further to the front of the volume, extend the mft_zone to cover the
* beginning of the volume as well. This is in order to protect the
* area reserved for the mft bitmap as well within the mft_zone itself.
* On non-standard volumes we don't protect it as well as the overhead
* would be higher than the speed increase we would get by doing it.
*/
tc = (8192 + 2 * vol->cluster_size - 1) / vol->cluster_size;
if (tc * vol->cluster_size < 16 * 1024)
tc = (16 * 1024 + vol->cluster_size - 1) / vol->cluster_size;
if (vol->mft_zone_start <= tc)
vol->mft_zone_start = (ntfs_cluster_t)0;
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->mft_zone_start = %x\n",
vol->mft_zone_start);
/*
* Need to cap the mft zone on non-standard volumes so that it does
* not point outside the boundaries of the volume, we do this by
* halving the zone size until we are inside the volume.
*/
vol->mft_zone_end = vol->mft_lcn + mft_zone_size;
while (vol->mft_zone_end >= vol->nr_clusters) {
mft_zone_size >>= 1;
vol->mft_zone_end = vol->mft_lcn + mft_zone_size;
}
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->mft_zone_end = %x\n",
vol->mft_zone_end);
/*
* Set the current position within each data zone to the start of the
* respective zone.
*/
vol->data1_zone_pos = vol->mft_zone_end;
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->data1_zone_pos = %x\n",
vol->data1_zone_pos);
vol->data2_zone_pos = (ntfs_cluster_t)0;
ntfs_debug(DEBUG_FILE3, "ntfs_init_volume: vol->data2_zone_pos = %x\n",
vol->data2_zone_pos);
/* Set the mft data allocation position to mft record 24. */
vol->mft_data_pos = 24UL;
/* This will be initialized later. */
vol->upcase = 0;
vol->upcase_length = 0;
vol->mft_ino = 0;
return 0;
}
static void ntfs_init_upcase(ntfs_inode *upcase)
{
ntfs_io io;
#define UPCASE_LENGTH 256
upcase->vol->upcase = ntfs_malloc(UPCASE_LENGTH << 1);
if (!upcase->vol->upcase)
return;
io.fn_put = ntfs_put;
io.fn_get = 0;
io.param = (char*)upcase->vol->upcase;
io.size = UPCASE_LENGTH << 1;
ntfs_read_attr(upcase, upcase->vol->at_data, 0, 0, &io);
upcase->vol->upcase_length = io.size >> 1;
}
static int process_attrdef(ntfs_inode* attrdef, ntfs_u8* def)
{
int type = NTFS_GETU32(def+0x80);
int check_type = 0;
ntfs_volume *vol = attrdef->vol;
ntfs_u16* name = (ntfs_u16*)def;
if (!type) {
ntfs_debug(DEBUG_OTHER, "process_atrdef: finished processing "
"and returning 1\n");
return 1;
}
if (ntfs_ua_strncmp(name, "$STANDARD_INFORMATION", 64) == 0) {
vol->at_standard_information = type;
check_type = 0x10;
} else if (ntfs_ua_strncmp(name, "$ATTRIBUTE_LIST", 64) == 0) {
vol->at_attribute_list = type;
check_type = 0x20;
} else if (ntfs_ua_strncmp(name, "$FILE_NAME", 64) == 0) {
vol->at_file_name = type;
check_type = 0x30;
} else if (ntfs_ua_strncmp(name, "$VOLUME_VERSION", 64) == 0) {
vol->at_volume_version = type;
check_type = 0x40;
} else if (ntfs_ua_strncmp(name, "$SECURITY_DESCRIPTOR", 64) == 0) {
vol->at_security_descriptor = type;
check_type = 0x50;
} else if (ntfs_ua_strncmp(name, "$VOLUME_NAME", 64) == 0) {
vol->at_volume_name = type;
check_type = 0x60;
} else if (ntfs_ua_strncmp(name, "$VOLUME_INFORMATION", 64) == 0) {
vol->at_volume_information = type;
check_type = 0x70;
} else if (ntfs_ua_strncmp(name, "$DATA", 64) == 0) {
vol->at_data = type;
check_type = 0x80;
} else if (ntfs_ua_strncmp(name, "$INDEX_ROOT", 64) == 0) {
vol->at_index_root = type;
check_type = 0x90;
} else if (ntfs_ua_strncmp(name, "$INDEX_ALLOCATION", 64) == 0) {
vol->at_index_allocation = type;
check_type = 0xA0;
} else if (ntfs_ua_strncmp(name, "$BITMAP", 64) == 0) {
vol->at_bitmap = type;
check_type = 0xB0;
} else if (ntfs_ua_strncmp(name, "$SYMBOLIC_LINK", 64) == 0 ||
ntfs_ua_strncmp(name, "$REPARSE_POINT", 64) == 0) {
vol->at_symlink = type;
check_type = 0xC0;
}
if (check_type && check_type != type) {
ntfs_error("process_attrdef: unexpected type 0x%x for 0x%x\n",
type, check_type);
return -EINVAL;
}
ntfs_debug(DEBUG_OTHER, "process_attrdef: found %s attribute of type "
"0x%x\n", check_type ? "known" : "unknown", type);
return 0;
}
int ntfs_init_attrdef(ntfs_inode* attrdef)
{
ntfs_u8 *buf;
ntfs_io io;
__s64 offset;
unsigned i;
int error;
ntfs_attribute *data;
ntfs_debug(DEBUG_BSD, "Entered ntfs_init_attrdef()\n");
buf = ntfs_malloc(4050); /* 90*45 */
if (!buf)
return -ENOMEM;
io.fn_put = ntfs_put;
io.fn_get = ntfs_get;
io.do_read = 1;
offset = 0;
data = ntfs_find_attr(attrdef, attrdef->vol->at_data, 0);
ntfs_debug(DEBUG_BSD, "In ntfs_init_attrdef() after call to "
"ntfs_find_attr.\n");
if (!data) {
ntfs_free(buf);
return -EINVAL;
}
do {
io.param = buf;
io.size = 4050;
ntfs_debug(DEBUG_BSD, "In ntfs_init_attrdef() going to call "
"ntfs_readwrite_attr.\n");
error = ntfs_readwrite_attr(attrdef, data, offset, &io);
ntfs_debug(DEBUG_BSD, "In ntfs_init_attrdef() after call to "
"ntfs_readwrite_attr.\n");
for (i = 0; !error && i <= io.size - 0xA0; i += 0xA0) {
ntfs_debug(DEBUG_BSD, "In ntfs_init_attrdef() going "
"to call process_attrdef.\n");
error = process_attrdef(attrdef, buf + i);
ntfs_debug(DEBUG_BSD, "In ntfs_init_attrdef() after "
"call to process_attrdef.\n");
}
offset += 4096;
} while (!error && io.size);
ntfs_debug(DEBUG_BSD, "Exiting ntfs_init_attrdef()\n");
ntfs_free(buf);
return error == 1 ? 0 : error;
}
/* ntfs_get_version will determine the NTFS version of the volume and will
* return the version in a BCD format, with the MSB being the major version
* number and the LSB the minor one. Otherwise return <0 on error.
* Example: version 3.1 will be returned as 0x0301. This has the obvious
* limitation of not coping with version numbers above 0x80 but that shouldn't
* be a problem... */
int ntfs_get_version(ntfs_inode* volume)
{
ntfs_attribute *volinfo;
volinfo = ntfs_find_attr(volume, volume->vol->at_volume_information, 0);
if (!volinfo)
return -EINVAL;
if (!volinfo->resident) {
ntfs_error("Volume information attribute is not resident!\n");
return -EINVAL;
}
return ((ntfs_u8*)volinfo->d.data)[8] << 8 |
((ntfs_u8*)volinfo->d.data)[9];
}
int ntfs_load_special_files(ntfs_volume *vol)
{
int error;
ntfs_inode upcase, attrdef, volume;
vol->mft_ino = (ntfs_inode*)ntfs_calloc(sizeof(ntfs_inode));
vol->mftmirr = (ntfs_inode*)ntfs_calloc(sizeof(ntfs_inode));
vol->bitmap = (ntfs_inode*)ntfs_calloc(sizeof(ntfs_inode));
vol->ino_flags = 4 | 2 | 1;
error = -ENOMEM;
ntfs_debug(DEBUG_BSD, "Going to load MFT\n");
if (!vol->mft_ino || (error = ntfs_init_inode(vol->mft_ino, vol,
FILE_Mft))) {
ntfs_error("Problem loading MFT\n");
return error;
}
ntfs_debug(DEBUG_BSD, "Going to load MIRR\n");
if ((error = ntfs_init_inode(vol->mftmirr, vol, FILE_MftMirr))) {
ntfs_error("Problem %d loading MFTMirr\n", error);
return error;
}
ntfs_debug(DEBUG_BSD, "Going to load BITMAP\n");
if ((error = ntfs_init_inode(vol->bitmap, vol, FILE_BitMap))) {
ntfs_error("Problem loading Bitmap\n");
return error;
}
ntfs_debug(DEBUG_BSD, "Going to load UPCASE\n");
error = ntfs_init_inode(&upcase, vol, FILE_UpCase);
if (error)
return error;
ntfs_init_upcase(&upcase);
ntfs_clear_inode(&upcase);
ntfs_debug(DEBUG_BSD, "Going to load ATTRDEF\n");
error = ntfs_init_inode(&attrdef, vol, FILE_AttrDef);
if (error)
return error;
error = ntfs_init_attrdef(&attrdef);
ntfs_clear_inode(&attrdef);
if (error)
return error;
/* Check for NTFS version and if Win2k version (ie. 3.0+) do not allow
* write access since the driver write support is broken. */
ntfs_debug(DEBUG_BSD, "Going to load VOLUME\n");
error = ntfs_init_inode(&volume, vol, FILE_Volume);
if (error)
return error;
if ((error = ntfs_get_version(&volume)) >= 0x0300 &&
!(NTFS_SB(vol)->s_flags & MS_RDONLY)) {
NTFS_SB(vol)->s_flags |= MS_RDONLY;
ntfs_error("Warning! NTFS volume version is Win2k+: Mounting "
"read-only\n");
}
ntfs_clear_inode(&volume);
if (error < 0)
return error;
ntfs_debug(DEBUG_BSD, "NTFS volume is v%d.%d\n", error >> 8,
error & 0xff);
return 0;
}
int ntfs_release_volume(ntfs_volume *vol)
{
if (((vol->ino_flags & 1) == 1) && vol->mft_ino) {
ntfs_clear_inode(vol->mft_ino);
ntfs_free(vol->mft_ino);
vol->mft_ino = 0;
}
if (((vol->ino_flags & 2) == 2) && vol->mftmirr) {
ntfs_clear_inode(vol->mftmirr);
ntfs_free(vol->mftmirr);
vol->mftmirr = 0;
}
if (((vol->ino_flags & 4) == 4) && vol->bitmap) {
ntfs_clear_inode(vol->bitmap);
ntfs_free(vol->bitmap);
vol->bitmap = 0;
}
ntfs_free(vol->mft);
ntfs_free(vol->upcase);
return 0;
}
/*
* Writes the volume size (units of clusters) into vol_size.
* Returns 0 if successful or error.
*/
int ntfs_get_volumesize(ntfs_volume *vol, ntfs_s64 *vol_size)
{
ntfs_io io;
char *cluster0;
if (!vol_size)
return -EFAULT;
cluster0 = ntfs_malloc(vol->cluster_size);
if (!cluster0)
return -ENOMEM;
io.fn_put = ntfs_put;
io.fn_get = ntfs_get;
io.param = cluster0;
io.do_read = 1;
io.size = vol->cluster_size;
ntfs_getput_clusters(vol, 0, 0, &io);
*vol_size = NTFS_GETU64(cluster0 + 0x28) >>
(ffs(NTFS_GETU8(cluster0 + 0xD)) - 1);
ntfs_free(cluster0);
return 0;
}
static int nc[16]={4,3,3,2,3,2,2,1,3,2,2,1,2,1,1,0};
int ntfs_get_free_cluster_count(ntfs_inode *bitmap)
{
ntfs_io io;
int offset, error, clusters;
unsigned char *bits = ntfs_malloc(2048);
if (!bits)
return -ENOMEM;
offset = clusters = 0;
io.fn_put = ntfs_put;
io.fn_get = ntfs_get;
while (1) {
register int i;
io.param = bits;
io.size = 2048;
error = ntfs_read_attr(bitmap, bitmap->vol->at_data, 0, offset,
&io);
if (error || io.size == 0)
break;
/* I never thought I would do loop unrolling some day */
for (i = 0; i < io.size - 8; ) {
clusters+=nc[bits[i]>>4];clusters+=nc[bits[i++] & 0xF];
clusters+=nc[bits[i]>>4];clusters+=nc[bits[i++] & 0xF];
clusters+=nc[bits[i]>>4];clusters+=nc[bits[i++] & 0xF];
clusters+=nc[bits[i]>>4];clusters+=nc[bits[i++] & 0xF];
clusters+=nc[bits[i]>>4];clusters+=nc[bits[i++] & 0xF];
clusters+=nc[bits[i]>>4];clusters+=nc[bits[i++] & 0xF];
clusters+=nc[bits[i]>>4];clusters+=nc[bits[i++] & 0xF];
clusters+=nc[bits[i]>>4];clusters+=nc[bits[i++] & 0xF];
}
while (i < io.size) {
clusters += nc[bits[i] >> 4];
clusters += nc[bits[i++] & 0xF];
}
offset += io.size;
}
ntfs_free(bits);
return clusters;
}
/*
* Insert the fixups for the record. The number and location of the fixes
* is obtained from the record header but we double check with @rec_size and
* use that as the upper boundary, if necessary overwriting the count value in
* the record header.
*
* We return 0 on success or -1 if fixup header indicated the beginning of the
* update sequence array to be beyond the valid limit.
*/
int ntfs_insert_fixups(unsigned char *rec, int rec_size)
{
int first;
int count;
int offset = -2;
ntfs_u16 fix;
first = NTFS_GETU16(rec + 4);
count = (rec_size >> NTFS_SECTOR_BITS) + 1;
if (first + count * 2 > NTFS_SECTOR_SIZE - 2) {
printk(KERN_CRIT "NTFS: ntfs_insert_fixups() detected corrupt "
"NTFS record update sequence array position. - "
"Cannot hotfix.\n");
return -1;
}
if (count != NTFS_GETU16(rec + 6)) {
printk(KERN_ERR "NTFS: ntfs_insert_fixups() detected corrupt "
"NTFS record update sequence array size. - "
"Applying hotfix.\n");
NTFS_PUTU16(rec + 6, count);
}
fix = (NTFS_GETU16(rec + first) + 1) & 0xffff;
if (fix == 0xffff || !fix)
fix = 1;
NTFS_PUTU16(rec + first, fix);
count--;
while (count--) {
first += 2;
offset += NTFS_SECTOR_SIZE;
NTFS_PUTU16(rec + first, NTFS_GETU16(rec + offset));
NTFS_PUTU16(rec + offset, fix);
}
return 0;
}
/**
* ntfs_allocate_clusters - allocate logical clusters on an ntfs volume
* @vol: volume on which to allocate clusters
* @location: preferred location for first allocated cluster
* @count: number of clusters to allocate
* @rl: address of pointer in which to return the allocated run list
* @rl_len: the number of elements returned in @*rl
*
* Allocate @*count clusters (LCNs), preferably beginning at @*location in the
* bitmap of the volume @vol. If @*location is -1, it does not matter where the
* clusters are. @rl is the address of a ntfs_runlist pointer which this
* function will allocate and fill with the runlist of the allocated clusters.
* It is the callers responsibility to ntfs_vfree() @*rl after she is finished
* with it. If the function was not successful, @*rl will be set to NULL.
* @*rl_len will contain the number of ntfs_runlist elements in @*rl or 0 if
* @*rl is NULL.
*
* Return 0 on success, or -errno on error. On success, @*location and @*count
* say what was really allocated. On -ENOSPC, @*location and @*count say what
* could have been allocated. If nothing could be allocated or a different
* error occured, @*location = -1 and @*count = 0.
*
* There are two data zones. First is the area between the end of the mft zone
* and the end of the volume, and second is the area between the start of the
* volume and the start of the mft zone. On unmodified/standard volumes, the
* second mft zone doesn't exist due to the mft zone being expanded to cover
* the start of volume in order to reserve space for the mft bitmap attribute.
*
* This is not the prettiest function but the complexity stems from the need of
* implementing the mft vs data zoned approach and from the fact that we have
* access to the lcn bitmap in portions of PAGE_SIZE bytes at a time, so we
* need to cope with crossing over boundaries of two pages. Further, the fact
* that the allocator allows for caller supplied hints as to the location of
* where allocation should begin and the fact that the allocator keeps track of
* where in the data zones the next natural allocation should occur, contribute
* to the complexity of the function. But it should all be worthwhile, because
* this allocator should: 1) be a full implementation of the MFT zone approach
* used by Windows, 2) cause reduction in fragmentation as much as possible,
* and 3) be speedy in allocations (the code is not optimized for speed, but
* the algorithm is, so further speed improvements are probably possible).
*
* FIXME: Really need finer-grained locking but this will do for the moment. I
* just want to kill all races and have a working allocator. When that is done,
* we can beautify... (AIA)
*
* FIXME: We should be monitoring cluster allocation and increment the MFT zone
* size dynamically but this is something for the future. We will just cause
* heavier fragmentation by not doing it and I am not even sure Windows would
* grow the MFT zone dynamically, so might even be correct not doing this. The
* overhead in doing dynamic MFT zone expansion would be very large and unlikely
* worth the effort. (AIA)
*
* TODO: I have added in double the required zone position pointer wrap around
* logic which can be optimized to having only one of the two logic sets.
* However, having the double logic will work fine, but if we have only one of
* the sets and we get it wrong somewhere, then we get into trouble, so
* removing the duplicate logic requires _very_ careful consideration of _all_
* possible code paths. So at least for now, I am leaving the double logic -
* better safe than sorry... (AIA)
*/
int ntfs_allocate_clusters(ntfs_volume *vol, ntfs_cluster_t *location,
ntfs_cluster_t *count, ntfs_runlist **rl, int *rl_len,
const NTFS_CLUSTER_ALLOCATION_ZONES zone)
{
ntfs_runlist *rl2 = NULL, *rlt;
ntfs_attribute *data;
ntfs_cluster_t buf_pos, zone_start, zone_end, mft_zone_size;
ntfs_cluster_t lcn, last_read_pos, prev_lcn = (ntfs_cluster_t)0;
ntfs_cluster_t initial_location, prev_run_len = (ntfs_cluster_t)0;
ntfs_cluster_t clusters = (ntfs_cluster_t)0;
unsigned char *buf, *byte, bit, search_zone, done_zones;
unsigned char pass, need_writeback;
int rlpos = 0, rlsize, buf_size, err = 0;
ntfs_io io;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Entering with *location = "
"0x%x, *count = 0x%x, zone = %s_ZONE.\n", *location,
*count, zone == DATA_ZONE ? "DATA" : "MFT");
buf = (char*)__get_free_page(GFP_NOFS);
if (!buf) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Returning "
"-ENOMEM.\n");
return -ENOMEM;
}
io.fn_put = ntfs_put;
io.fn_get = ntfs_get;
lock_kernel();
/* Get the $DATA attribute of $Bitmap. */
data = ntfs_find_attr(vol->bitmap, vol->at_data, 0);
if (!data) {
err = -EINVAL;
goto err_ret;
}
/*
* If no specific location was requested, use the current data zone
* position, otherwise use the requested location but make sure it lies
* outside the mft zone. Also set done_zones to 0 (no zones done) and
* pass depending on whether we are starting inside a zone (1) or
* at the beginning of a zone (2). If requesting from the MFT_ZONE, then
* we either start at the current position within the mft zone or at the
* specified position and if the latter is out of bounds then we start
* at the beginning of the MFT_ZONE.
*/
done_zones = 0;
pass = 1;
/*
* zone_start and zone_end are the current search range. search_zone
* is 1 for mft zone, 2 for data zone 1 (end of mft zone till end of
* volume) and 4 for data zone 2 (start of volume till start of mft
* zone).
*/
zone_start = *location;
if (zone_start < 0) {
if (zone == DATA_ZONE)
zone_start = vol->data1_zone_pos;
else
zone_start = vol->mft_zone_pos;
if (!zone_start)
/*
* Zone starts at beginning of volume which means a
* single pass is sufficient.
*/
pass = 2;
} else if (zone_start >= vol->mft_zone_start && zone_start <
vol->mft_zone_end && zone == DATA_ZONE) {
zone_start = vol->mft_zone_end;
pass = 2;
} else if ((zone_start < vol->mft_zone_start || zone_start >=
vol->mft_zone_end) && zone == MFT_ZONE) {
zone_start = vol->mft_lcn;
if (!vol->mft_zone_end)
zone_start = (ntfs_cluster_t)0;
pass = 2;
}
if (zone == DATA_ZONE) {
/* Skip searching the mft zone. */
done_zones |= 1;
if (zone_start >= vol->mft_zone_end) {
zone_end = vol->nr_clusters;
search_zone = 2;
} else {
zone_end = vol->mft_zone_start;
search_zone = 4;
}
} else /* if (zone == MFT_ZONE) */ {
zone_end = vol->mft_zone_end;
search_zone = 1;
}
/*
* buf_pos is the current bit position inside the bitmap. We use
* initial_location to determine whether or not to do a zone switch.
*/
buf_pos = initial_location = zone_start;
/* Loop until all clusters are allocated, i.e. clusters == 0. */
clusters = *count;
rlpos = rlsize = 0;
if (*count <= 0) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): *count <= 0, "
"returning -EINVAL.\n");
err = -EINVAL;
goto err_ret;
}
while (1) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Start of outer while "
"loop: done_zones = 0x%x, search_zone = %i, "
"pass = %i, zone_start = 0x%x, zone_end = "
"0x%x, initial_location = 0x%x, buf_pos = "
"0x%x, rlpos = %i, rlsize = %i.\n",
done_zones, search_zone, pass, zone_start,
zone_end, initial_location, buf_pos, rlpos,
rlsize);
/* Loop until we run out of free clusters. */
io.param = buf;
io.size = PAGE_SIZE;
io.do_read = 1;
last_read_pos = buf_pos >> 3;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): last_read_pos = "
"0x%x.\n", last_read_pos);
err = ntfs_readwrite_attr(vol->bitmap, data, last_read_pos,
&io);
if (err) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"ntfs_read_attr failed with error "
"code %i, going to err_ret.\n", -err);
goto err_ret;
}
if (!io.size) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): !io.size, "
"going to zone_pass_done.\n");
goto zone_pass_done;
}
buf_size = io.size << 3;
lcn = buf_pos & 7;
buf_pos &= ~7;
need_writeback = 0;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Before inner while "
"loop: buf_size = 0x%x, lcn = 0x%x, buf_pos = "
"0x%x, need_writeback = %i.\n", buf_size, lcn,
buf_pos, need_writeback);
while (lcn < buf_size && lcn + buf_pos < zone_end) {
byte = buf + (lcn >> 3);
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): In inner "
"while loop: buf_size = 0x%x, lcn = "
"0x%x, buf_pos = 0x%x, need_writeback "
"= %i, byte ofs = 0x%x, *byte = "
"0x%x.\n", buf_size, lcn, buf_pos,
need_writeback, lcn >> 3, *byte);
/* Skip full bytes. */
if (*byte == 0xff) {
lcn += 8;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"continuing while loop 1.\n");
continue;
}
bit = 1 << (lcn & 7);
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): bit = %i.\n",
bit);
/* If the bit is already set, go onto the next one. */
if (*byte & bit) {
lcn++;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"continuing while loop 2.\n");
continue;
}
/* Allocate the bitmap bit. */
*byte |= bit;
/* We need to write this bitmap buffer back to disk! */
need_writeback = 1;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): *byte = "
"0x%x, need_writeback = %i.\n", *byte,
need_writeback);
/* Reallocate memory if necessary. */
if ((rlpos + 2) * sizeof(ntfs_runlist) >= rlsize) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Reallocating space.\n");
/* Setup first free bit return value. */
if (!rl2) {
*location = lcn + buf_pos;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): *location = "
"0x%x.\n", *location);
}
rlsize += PAGE_SIZE;
rlt = ntfs_vmalloc(rlsize);
if (!rlt) {
err = -ENOMEM;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): Failed to "
"allocate memory, "
"returning -ENOMEM, "
"going to "
"wb_err_ret.\n");
goto wb_err_ret;
}
if (rl2) {
ntfs_memcpy(rlt, rl2, rlsize -
PAGE_SIZE);
ntfs_vfree(rl2);
}
rl2 = rlt;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Reallocated memory, rlsize = "
"0x%x.\n", rlsize);
}
/*
* Coalesce with previous run if adjacent LCNs.
* Otherwise, append a new run.
*/
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Adding run "
"(lcn 0x%x, len 0x%x), prev_lcn = "
"0x%x, lcn = 0x%x, buf_pos = 0x%x, "
"prev_run_len = 0x%x, rlpos = %i.\n",
lcn + buf_pos, 1, prev_lcn, lcn,
buf_pos, prev_run_len, rlpos);
if (prev_lcn == lcn + buf_pos - prev_run_len && rlpos) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Coalescing to run (lcn 0x%x, "
"len 0x%x).\n",
rl2[rlpos - 1].lcn,
rl2[rlpos - 1].len);
rl2[rlpos - 1].len = ++prev_run_len;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Run now (lcn 0x%x, len 0x%x), "
"prev_run_len = 0x%x.\n",
rl2[rlpos - 1].lcn,
rl2[rlpos - 1].len,
prev_run_len);
} else {
if (rlpos)
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): Adding new run, "
"(previous run lcn "
"0x%x, len 0x%x).\n",
rl2[rlpos - 1].lcn,
rl2[rlpos - 1].len);
else
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): Adding new run, "
"is first run.\n");
rl2[rlpos].lcn = prev_lcn = lcn + buf_pos;
rl2[rlpos].len = prev_run_len =
(ntfs_cluster_t)1;
rlpos++;
}
/* Done? */
if (!--clusters) {
ntfs_cluster_t tc;
/*
* Update the current zone position. Positions
* of already scanned zones have been updated
* during the respective zone switches.
*/
tc = lcn + buf_pos + 1;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Done. Updating current zone "
"position, tc = 0x%x, "
"search_zone = %i.\n", tc,
search_zone);
switch (search_zone) {
case 1:
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): Before checks, "
"vol->mft_zone_pos = "
"0x%x.\n",
vol->mft_zone_pos);
if (tc >= vol->mft_zone_end) {
vol->mft_zone_pos =
vol->mft_lcn;
if (!vol->mft_zone_end)
vol->mft_zone_pos =
(ntfs_cluster_t)0;
} else if ((initial_location >=
vol->mft_zone_pos ||
tc > vol->mft_zone_pos)
&& tc >= vol->mft_lcn)
vol->mft_zone_pos = tc;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): After checks, "
"vol->mft_zone_pos = "
"0x%x.\n",
vol->mft_zone_pos);
break;
case 2:
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): Before checks, "
"vol->data1_zone_pos = "
"0x%x.\n",
vol->data1_zone_pos);
if (tc >= vol->nr_clusters)
vol->data1_zone_pos =
vol->mft_zone_end;
else if ((initial_location >=
vol->data1_zone_pos ||
tc > vol->data1_zone_pos)
&& tc >= vol->mft_zone_end)
vol->data1_zone_pos = tc;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): After checks, "
"vol->data1_zone_pos = "
"0x%x.\n",
vol->data1_zone_pos);
break;
case 4:
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): Before checks, "
"vol->data2_zone_pos = "
"0x%x.\n",
vol->data2_zone_pos);
if (tc >= vol->mft_zone_start)
vol->data2_zone_pos =
(ntfs_cluster_t)0;
else if (initial_location >=
vol->data2_zone_pos ||
tc > vol->data2_zone_pos)
vol->data2_zone_pos = tc;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): After checks, "
"vol->data2_zone_pos = "
"0x%x.\n",
vol->data2_zone_pos);
break;
default:
BUG();
}
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Going to done_ret.\n");
goto done_ret;
}
lcn++;
}
buf_pos += buf_size;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): After inner while "
"loop: buf_size = 0x%x, lcn = 0x%x, buf_pos = "
"0x%x, need_writeback = %i.\n", buf_size, lcn,
buf_pos, need_writeback);
if (need_writeback) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Writing "
"back.\n");
need_writeback = 0;
io.param = buf;
io.do_read = 0;
err = ntfs_readwrite_attr(vol->bitmap, data,
last_read_pos, &io);
if (err) {
ntfs_error(__FUNCTION__ "(): Bitmap writeback "
"failed in read next buffer "
"code path with error code "
"%i.\n", -err);
goto err_ret;
}
}
if (buf_pos < zone_end) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Continuing "
"outer while loop, buf_pos = 0x%x, "
"zone_end = 0x%x.\n", buf_pos,
zone_end);
continue;
}
zone_pass_done: /* Finished with the current zone pass. */
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): At zone_pass_done, "
"pass = %i.\n", pass);
if (pass == 1) {
/*
* Now do pass 2, scanning the first part of the zone
* we omitted in pass 1.
*/
pass = 2;
zone_end = zone_start;
switch (search_zone) {
case 1: /* mft_zone */
zone_start = vol->mft_zone_start;
break;
case 2: /* data1_zone */
zone_start = vol->mft_zone_end;
break;
case 4: /* data2_zone */
zone_start = (ntfs_cluster_t)0;
break;
default:
BUG();
}
/* Sanity check. */
if (zone_end < zone_start)
zone_end = zone_start;
buf_pos = zone_start;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Continuing "
"outer while loop, pass = 2, "
"zone_start = 0x%x, zone_end = 0x%x, "
"buf_pos = 0x%x.\n");
continue;
} /* pass == 2 */
done_zones_check:
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): At done_zones_check, "
"search_zone = %i, done_zones before = 0x%x, "
"done_zones after = 0x%x.\n",
search_zone, done_zones, done_zones |
search_zone);
done_zones |= search_zone;
if (done_zones < 7) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Switching "
"zone.\n");
/* Now switch to the next zone we haven't done yet. */
pass = 1;
switch (search_zone) {
case 1:
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Switching from mft zone to "
"data1 zone.\n");
/* Update mft zone position. */
if (rlpos) {
ntfs_cluster_t tc;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): Before checks, "
"vol->mft_zone_pos = "
"0x%x.\n",
vol->mft_zone_pos);
tc = rl2[rlpos - 1].lcn +
rl2[rlpos - 1].len;
if (tc >= vol->mft_zone_end) {
vol->mft_zone_pos =
vol->mft_lcn;
if (!vol->mft_zone_end)
vol->mft_zone_pos =
(ntfs_cluster_t)0;
} else if ((initial_location >=
vol->mft_zone_pos ||
tc > vol->mft_zone_pos)
&& tc >= vol->mft_lcn)
vol->mft_zone_pos = tc;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): After checks, "
"vol->mft_zone_pos = "
"0x%x.\n",
vol->mft_zone_pos);
}
/* Switch from mft zone to data1 zone. */
switch_to_data1_zone: search_zone = 2;
zone_start = initial_location =
vol->data1_zone_pos;
zone_end = vol->nr_clusters;
if (zone_start == vol->mft_zone_end)
pass = 2;
if (zone_start >= zone_end) {
vol->data1_zone_pos = zone_start =
vol->mft_zone_end;
pass = 2;
}
break;
case 2:
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Switching from data1 zone to "
"data2 zone.\n");
/* Update data1 zone position. */
if (rlpos) {
ntfs_cluster_t tc;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): Before checks, "
"vol->data1_zone_pos = "
"0x%x.\n",
vol->data1_zone_pos);
tc = rl2[rlpos - 1].lcn +
rl2[rlpos - 1].len;
if (tc >= vol->nr_clusters)
vol->data1_zone_pos =
vol->mft_zone_end;
else if ((initial_location >=
vol->data1_zone_pos ||
tc > vol->data1_zone_pos)
&& tc >= vol->mft_zone_end)
vol->data1_zone_pos = tc;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): After checks, "
"vol->data1_zone_pos = "
"0x%x.\n",
vol->data1_zone_pos);
}
/* Switch from data1 zone to data2 zone. */
search_zone = 4;
zone_start = initial_location =
vol->data2_zone_pos;
zone_end = vol->mft_zone_start;
if (!zone_start)
pass = 2;
if (zone_start >= zone_end) {
vol->data2_zone_pos = zone_start =
initial_location =
(ntfs_cluster_t)0;
pass = 2;
}
break;
case 4:
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Switching from data2 zone to "
"data1 zone.\n");
/* Update data2 zone position. */
if (rlpos) {
ntfs_cluster_t tc;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): Before checks, "
"vol->data2_zone_pos = "
"0x%x.\n",
vol->data2_zone_pos);
tc = rl2[rlpos - 1].lcn +
rl2[rlpos - 1].len;
if (tc >= vol->mft_zone_start)
vol->data2_zone_pos =
(ntfs_cluster_t)0;
else if (initial_location >=
vol->data2_zone_pos ||
tc > vol->data2_zone_pos)
vol->data2_zone_pos = tc;
ntfs_debug(DEBUG_OTHER, __FUNCTION__
"(): After checks, "
"vol->data2_zone_pos = "
"0x%x.\n",
vol->data2_zone_pos);
}
/* Switch from data2 zone to data1 zone. */
goto switch_to_data1_zone; /* See above. */
default:
BUG();
}
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): After zone "
"switch, search_zone = %i, pass = %i, "
"initial_location = 0x%x, zone_start "
"= 0x%x, zone_end = 0x%x.\n",
search_zone, pass, initial_location,
zone_start, zone_end);
buf_pos = zone_start;
if (zone_start == zone_end) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): "
"Empty zone, going to "
"done_zones_check.\n");
/* Empty zone. Don't bother searching it. */
goto done_zones_check;
}
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Continuing "
"outer while loop.\n");
continue;
} /* done_zones == 7 */
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): All zones are "
"finished.\n");
/*
* All zones are finished! If DATA_ZONE, shrink mft zone. If
* MFT_ZONE, we have really run out of space.
*/
mft_zone_size = vol->mft_zone_end - vol->mft_zone_start;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): vol->mft_zone_start "
"= 0x%x, vol->mft_zone_end = 0x%x, "
"mft_zone_size = 0x%x.\n", vol->mft_zone_start,
vol->mft_zone_end, mft_zone_size);
if (zone == MFT_ZONE || mft_zone_size <= (ntfs_cluster_t)0) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): No free "
"clusters left, returning -ENOSPC, "
"going to fail_ret.\n");
/* Really no more space left on device. */
err = -ENOSPC;
goto fail_ret;
} /* zone == DATA_ZONE && mft_zone_size > 0 */
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Shrinking mft "
"zone.\n");
zone_end = vol->mft_zone_end;
mft_zone_size >>= 1;
if (mft_zone_size > (ntfs_cluster_t)0)
vol->mft_zone_end = vol->mft_zone_start + mft_zone_size;
else /* mft zone and data2 zone no longer exist. */
vol->data2_zone_pos = vol->mft_zone_start =
vol->mft_zone_end = (ntfs_cluster_t)0;
if (vol->mft_zone_pos >= vol->mft_zone_end) {
vol->mft_zone_pos = vol->mft_lcn;
if (!vol->mft_zone_end)
vol->mft_zone_pos = (ntfs_cluster_t)0;
}
buf_pos = zone_start = initial_location =
vol->data1_zone_pos = vol->mft_zone_end;
search_zone = 2;
pass = 2;
done_zones &= ~2;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): After shrinking mft "
"zone, mft_zone_size = 0x%x, "
"vol->mft_zone_start = 0x%x, vol->mft_zone_end "
"= 0x%x, vol->mft_zone_pos = 0x%x, search_zone "
"= 2, pass = 2, dones_zones = 0x%x, zone_start "
"= 0x%x, zone_end = 0x%x, vol->data1_zone_pos "
"= 0x%x, continuing outer while loop.\n",
mft_zone_size, vol->mft_zone_start,
vol->mft_zone_end, vol->mft_zone_pos,
search_zone, pass, done_zones, zone_start,
zone_end, vol->data1_zone_pos);
}
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): After outer while loop.\n");
done_ret:
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): At done_ret.\n");
rl2[rlpos].lcn = (ntfs_cluster_t)-1;
rl2[rlpos].len = (ntfs_cluster_t)0;
*rl = rl2;
*rl_len = rlpos;
if (need_writeback) {
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Writing back.\n");
need_writeback = 0;
io.param = buf;
io.do_read = 0;
err = ntfs_readwrite_attr(vol->bitmap, data, last_read_pos,
&io);
if (err) {
ntfs_error(__FUNCTION__ "(): Bitmap writeback failed "
"in done code path with error code "
"%i.\n", -err);
goto err_ret;
}
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Wrote 0x%Lx bytes.\n",
io.size);
}
done_fail_ret:
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): At done_fail_ret (follows "
"done_ret).\n");
unlock_kernel();
free_page((unsigned long)buf);
if (err)
ntfs_debug(DEBUG_FILE3, __FUNCTION__ "(): Failed to allocate "
"clusters. Returning with error code %i.\n",
-err);
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Syncing $Bitmap inode.\n");
if (ntfs_update_inode(vol->bitmap))
ntfs_error(__FUNCTION__ "(): Failed to sync inode $Bitmap. "
"Continuing anyway.\n");
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Returning with code %i.\n",
err);
return err;
fail_ret:
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): At fail_ret.\n");
if (rl2) {
if (err == -ENOSPC) {
/* Return first free lcn and count of free clusters. */
*location = rl2[0].lcn;
*count -= clusters;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): err = "
"-ENOSPC, *location = 0x%x, *count = "
"0x%x.\n", *location, *count);
}
/* Deallocate all allocated clusters. */
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Deallocating "
"allocated clusters.\n");
ntfs_deallocate_clusters(vol, rl2, rlpos);
/* Free the runlist. */
ntfs_vfree(rl2);
} else {
if (err == -ENOSPC) {
/* Nothing free at all. */
*location = vol->data1_zone_pos; /* Irrelevant... */
*count = 0;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): No space "
"left at all, err = -ENOSPC, *location "
"= 0x%x, *count = 0.\n", *location);
}
}
*rl = NULL;
*rl_len = 0;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): *rl = NULL, *rl_len = 0, "
"going to done_fail_ret.\n");
goto done_fail_ret;
wb_err_ret:
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): At wb_err_ret.\n");
if (need_writeback) {
int __err;
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): Writing back.\n");
io.param = buf;
io.do_read = 0;
__err = ntfs_readwrite_attr(vol->bitmap, data, last_read_pos,
&io);
if (__err)
ntfs_error(__FUNCTION__ "(): Bitmap writeback failed "
"in error code path with error code "
"%i.\n", -__err);
need_writeback = 0;
}
err_ret:
ntfs_debug(DEBUG_OTHER, __FUNCTION__ "(): At err_ret, *location = -1, "
"*count = 0, going to fail_ret.\n");
*location = -1;
*count = 0;
goto fail_ret;
}
/*
* IMPORTANT: Caller has to hold big kernel lock or the race monster will come
* to get you! (-;
* TODO: Need our own lock for bitmap accesses but BKL is more secure for now,
* considering we might not have covered all places with a lock yet. In that
* case the BKL offers a one way exclusion which is better than no exclusion
* at all... (AIA)
*/
static int ntfs_clear_bitrange(ntfs_inode *bitmap,
const ntfs_cluster_t start_bit, const ntfs_cluster_t count)
{
ntfs_cluster_t buf_size, bit, nr_bits = count;
unsigned char *buf, *byte;
int err;
ntfs_io io;
io.fn_put = ntfs_put;
io.fn_get = ntfs_get;
/* Calculate the required buffer size in bytes. */
buf_size = (ntfs_cluster_t)((start_bit & 7) + nr_bits + 7) >> 3;
if (buf_size <= (ntfs_cluster_t)(64 * 1024))
buf = ntfs_malloc(buf_size);
else
buf = ntfs_vmalloc(buf_size);
if (!buf)
return -ENOMEM;
/* Read the bitmap from the data attribute. */
io.param = byte = buf;
io.size = buf_size;
err = ntfs_read_attr(bitmap, bitmap->vol->at_data, 0, start_bit >> 3,
&io);
if (err || io.size != buf_size)
goto err_out;
/* Now clear the bits in the read bitmap. */
bit = start_bit & 7;
while (bit && nr_bits) { /* Process first partial byte, if present. */
*byte &= ~(1 << bit++);
nr_bits--;
bit &= 7;
if (!bit)
byte++;
}
while (nr_bits >= 8) { /* Process full bytes. */
*byte = 0;
nr_bits -= 8;
byte++;
}
bit = 0;
while (nr_bits) { /* Process last partial byte, if present. */
*byte &= ~(1 << bit);
nr_bits--;
bit++;
}
/* Write the modified bitmap back to disk. */
io.param = buf;
io.size = buf_size;
err = ntfs_write_attr(bitmap, bitmap->vol->at_data, 0, start_bit >> 3,
&io);
err_out:
if (buf_size <= (ntfs_cluster_t)(64 * 1024))
ntfs_free(buf);
else
ntfs_vfree(buf);
if (!err && io.size != buf_size)
err = -EIO;
return err;
}
/*
* See comments for lack of zone adjustments below in the description of the
* function ntfs_deallocate_clusters().
*/
int ntfs_deallocate_cluster_run(const ntfs_volume *vol,
const ntfs_cluster_t lcn, const ntfs_cluster_t len)
{
int err;
lock_kernel();
err = ntfs_clear_bitrange(vol->bitmap, lcn, len);
unlock_kernel();
return err;
}
/*
* This is inefficient, but logically trivial, so will do for now. Note, we
* do not touch the mft nor the data zones here because we want to minimize
* recycling of clusters to enhance the chances of data being undeleteable.
* Also we don't want the overhead. Instead we do one additional sweep of the
* current data zone during cluster allocation to check for freed clusters.
*/
int ntfs_deallocate_clusters(const ntfs_volume *vol, const ntfs_runlist *rl,
const int rl_len)
{
int i, err;
lock_kernel();
for (i = err = 0; i < rl_len && !err; i++)
err = ntfs_clear_bitrange(vol->bitmap, rl[i].lcn, rl[i].len);
unlock_kernel();
return err;
}
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