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ntfs-3g/libntfs/index.c

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/*
* index.c - NTFS index handling. Part of the Linux-NTFS project.
*
* Copyright (c) 2004-2005 Anton Altaparmakov
* Copyright (c) 2005 Yura Pakhuchiy
*
* 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 Linux-NTFS
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "config.h"
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include "attrib.h"
#include "collate.h"
#include "debug.h"
#include "index.h"
#include "mst.h"
#include "dir.h"
/**
* ntfs_index_ctx_get - allocate and initialize a new index context
* @ni: ntfs inode with which to initialize the context
* @name: name of the which context describes
* @name_len: length of the index name
*
* Allocate a new index context, initialize it with @ni and return it.
* Return NULL if allocation failed.
*/
ntfs_index_context *ntfs_index_ctx_get(ntfs_inode *ni,
ntfschar *name, u32 name_len)
{
ntfs_index_context *ictx;
if (!ni) {
errno = EINVAL;
return NULL;
}
if (ni->nr_extents == -1)
ni = ni->base_ni;
ictx = malloc(sizeof(ntfs_index_context));
if (ictx)
*ictx = (ntfs_index_context) {
.ni = ni,
.name = name,
.name_len = name_len,
};
return ictx;
}
/**
* ntfs_index_ctx_put - release an index context
* @ictx: index context to free
*
* Release the index context @ictx, releasing all associated resources.
*/
void ntfs_index_ctx_put(ntfs_index_context *ictx)
{
if (ictx->entry) {
if (ictx->is_in_root) {
if (ictx->actx)
ntfs_attr_put_search_ctx(ictx->actx);
} else {
/* Write out index block it it's dirty. */
if (ictx->ia_dirty) {
if (ntfs_attr_mst_pwrite(ictx->ia_na,
ictx->ia_vcn <<
ictx->ni->vol->
cluster_size_bits,
1, ictx->block_size,
ictx->ia) != 1)
ntfs_error(, "Failed to write out "
"index block.");
}
/* Free resources. */
free(ictx->ia);
ntfs_attr_close(ictx->ia_na);
}
}
free(ictx);
}
/**
* ntfs_index_ctx_reinit - reinitialize an index context
* @ictx: index context to reinitialize
*
* Reintialize the index context @ictx so it can be used for ntfs_index_lookup.
*/
void ntfs_index_ctx_reinit(ntfs_index_context *ictx)
{
if (ictx->entry) {
if (ictx->is_in_root) {
if (ictx->actx)
ntfs_attr_put_search_ctx(ictx->actx);
} else {
/* Write out index block it it's dirty. */
if (ictx->ia_dirty) {
if (ntfs_attr_mst_pwrite(ictx->ia_na,
ictx->ia_vcn <<
ictx->ni->vol->
cluster_size_bits,
1, ictx->block_size,
ictx->ia) != 1)
ntfs_error(, "Failed to write out "
"index block.");
}
/* Free resources. */
free(ictx->ia);
ntfs_attr_close(ictx->ia_na);
}
}
*ictx = (ntfs_index_context) {
.ni = ictx->ni,
.name = ictx->name,
.name_len = ictx->name_len,
};
}
/**
* ntfs_index_lookup - find a key in an index and return its index entry
* @key: [IN] key for which to search in the index
* @key_len: [IN] length of @key in bytes
* @ictx: [IN/OUT] context describing the index and the returned entry
*
* Before calling ntfs_index_lookup(), @ictx must have been obtained from a
* call to ntfs_index_ctx_get().
*
* Look for the @key in the index specified by the index lookup context @ictx.
* ntfs_index_lookup() walks the contents of the index looking for the @key.
*
* If the @key is found in the index, 0 is returned and @ictx is setup to
* describe the index entry containing the matching @key. @ictx->entry is the
* index entry and @ictx->data and @ictx->data_len are the index entry data and
* its length in bytes, respectively.
*
* If the @key is not found in the index, -1 is returned, errno = ENOENT and
* @ictx is setup to describe the index entry whose key collates immediately
* after the search @key, i.e. this is the position in the index at which
* an index entry with a key of @key would need to be inserted.
*
* If an error occurs return -1, set errno to error code and @ictx is left
* untouched.
*
* When finished with the entry and its data, call ntfs_index_ctx_put() to free
* the context and other associated resources.
*
* If the index entry was modified, call ntfs_index_entry_mark_dirty() before
* the call to ntfs_index_ctx_put() to ensure that the changes are written
* to disk.
*/
int ntfs_index_lookup(const void *key, const int key_len,
ntfs_index_context *ictx)
{
COLLATION_RULES cr;
VCN vcn;
ntfs_inode *ni = ictx->ni;
ntfs_volume *vol = ni->vol;
INDEX_ROOT *ir;
INDEX_ENTRY *ie;
INDEX_ALLOCATION *ia = NULL;
u8 *index_end;
ntfs_attr_search_ctx *actx;
ntfs_attr *na = NULL;
int rc, err = 0;
ntfs_debug("Entering.");
if (!key || key_len <= 0) {
errno = EINVAL;
return -1;
}
actx = ntfs_attr_get_search_ctx(ni, NULL);
if (!actx) {
err = ENOMEM;
goto err_out;
}
/* Find the index root attribute in the mft record. */
err = ntfs_attr_lookup(AT_INDEX_ROOT, ictx->name, ictx->name_len,
CASE_SENSITIVE, 0, NULL, 0, actx);
if (err) {
if (errno == ENOENT) {
ntfs_error(sb, "Index root attribute missing in inode "
"0x%llx.", ni->mft_no);
err = EIO;
} else
err = errno;
goto err_out;
}
/* Get to the index root value (it has been verified in read_inode). */
ir = (INDEX_ROOT*)((u8*)actx->attr +
le16_to_cpu(actx->attr->value_offset));
index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
/* Save index block size for future use. */
ictx->block_size = ir->index_block_size;
/* Get collation rule type and validate it. */
cr = ir->collation_rule;
if (!ntfs_is_collation_rule_supported(cr)) {
ntfs_error(sb, "Index uses unsupported collation rule 0x%x. "
"Aborting lookup.", (unsigned)le32_to_cpu(cr));
err = EOPNOTSUPP;
goto err_out;
}
/* The first index entry. */
ie = (INDEX_ENTRY*)((u8*)&ir->index +
le32_to_cpu(ir->index.entries_offset));
/*
* Loop until we exceed valid memory (corruption case) or until we
* reach the last entry.
*/
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
/* Bounds checks. */
if ((u8*)ie < (u8*)actx->mrec || (u8*)ie +
sizeof(INDEX_ENTRY_HEADER) > index_end ||
(u8*)ie + le16_to_cpu(ie->length) > index_end)
goto idx_err_out;
/*
* The last entry cannot contain a key. It can however contain
* a pointer to a child node in the B+tree so we just break out.
*/
if (ie->flags & INDEX_ENTRY_END)
break;
/* If the keys match perfectly, we setup @ictx and return 0. */
if ((key_len == le16_to_cpu(ie->key_length)) && !memcmp(key,
&ie->key, key_len)) {
ir_done:
ictx->is_in_root = TRUE;
ictx->actx = actx;
ictx->ia = NULL;
ictx->ir = ir;
done:
ictx->entry = ie;
ictx->data = (u8*)ie + offsetof(INDEX_ENTRY, key);
ictx->data_len = le16_to_cpu(ie->key_length);
ntfs_debug("Done.");
if (err) {
errno = err;
return -1;
}
return 0;
}
/*
* Not a perfect match, need to do full blown collation so we
* know which way in the B+tree we have to go.
*/
rc = ntfs_collate(vol, cr, key, key_len, &ie->key,
le16_to_cpu(ie->key_length));
if (rc == NTFS_COLLATION_ERROR) {
ntfs_error(, "Collation error. Probably filename "
"contain invalid characters.");
err = ERANGE;
goto err_out;
}
/*
* If @key collates before the key of the current entry, there
* is definitely no such key in this index but we might need to
* descend into the B+tree so we just break out of the loop.
*/
if (rc == -1)
break;
/*
* A match should never happen as the memcmp() call should have
* caught it, but we still treat it correctly.
*/
if (!rc)
goto ir_done;
/* The keys are not equal, continue the search. */
}
/*
* We have finished with this index without success. Check for the
* presence of a child node and if not present setup @ictx and return
* -1 with errno ENOENT.
*/
if (!(ie->flags & INDEX_ENTRY_NODE)) {
ntfs_debug("Entry not found.");
err = ENOENT;
goto ir_done;
} /* Child node present, descend into it. */
/* Get the starting vcn of the index_block holding the child node. */
vcn = sle64_to_cpup((sle64*)((u8*)ie + le16_to_cpu(ie->length) - 8));
/* We are done with the index root. Release attribute search ctx. */
ntfs_attr_put_search_ctx(actx);
actx = NULL;
/* Open INDEX_ALLOCATION. */
na = ntfs_attr_open(ni, AT_INDEX_ALLOCATION,
ictx->name, ictx->name_len);
if (!na) {
ntfs_error(sb, "No index allocation attribute but index entry "
"requires one. Inode 0x%llx is corrupt or "
"library bug.", ni->mft_no);
goto err_out;
}
/* Allocate memory to store index block. */
ia = malloc(ictx->block_size);
if (!ia) {
ntfs_error(, "Not enough memory to allocate buffer for index"
" allocation.");
err = ENOMEM;
goto err_out;
}
descend_into_child_node:
ntfs_debug("Descend into node with VCN %lld.", vcn);
/* Read index allocation block. */
if (ntfs_attr_mst_pread(na, vcn << vol->cluster_size_bits, 1,
ictx->block_size, ia) != 1) {
ntfs_error(, "Failed to read index allocation.");
goto err_out;
}
/* Catch multi sector transfer fixup errors. */
if (!ntfs_is_indx_record(ia->magic)) {
ntfs_error(sb, "Index record with vcn 0x%llx is corrupt. "
"Corrupt inode 0x%llx. Run chkdsk.",
(long long)vcn, ni->mft_no);
goto err_out;
}
if (sle64_to_cpu(ia->index_block_vcn) != vcn) {
ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is "
"different from expected VCN (0x%llx). Inode "
"0x%llx is corrupt or driver bug.",
(unsigned long long)
sle64_to_cpu(ia->index_block_vcn),
(unsigned long long)vcn, ni->mft_no);
goto err_out;
}
if (le32_to_cpu(ia->index.allocated_size) + 0x18 != ictx->block_size) {
ntfs_error(sb, "Index buffer (VCN 0x%llx) of inode 0x%llx has "
"a size (%u) differing from the index "
"specified size (%u). Inode is corrupt or "
"driver bug.", (unsigned long long)vcn,
ni->mft_no, (unsigned)
le32_to_cpu(ia->index.allocated_size) + 0x18,
(unsigned)ictx->block_size);
goto err_out;
}
index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
if (index_end > (u8*)ia + ictx->block_size) {
ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of inode "
"0x%llx exceeds maximum size.",
(unsigned long long)vcn, ni->mft_no);
goto err_out;
}
/* The first index entry. */
ie = (INDEX_ENTRY*)((u8*)&ia->index +
le32_to_cpu(ia->index.entries_offset));
/*
* Iterate similar to above big loop but applied to index buffer, thus
* loop until we exceed valid memory (corruption case) or until we
* reach the last entry.
*/
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
/* Bounds checks. */
if ((u8*)ie < (u8*)ia || (u8*)ie +
sizeof(INDEX_ENTRY_HEADER) > index_end ||
(u8*)ie + le16_to_cpu(ie->length) > index_end) {
ntfs_error(sb, "Index entry out of bounds in inode "
"0x%llx.", ni->mft_no);
goto err_out;
}
/*
* The last entry cannot contain a key. It can however contain
* a pointer to a child node in the B+tree so we just break out.
*/
if (ie->flags & INDEX_ENTRY_END)
break;
/* If the keys match perfectly, we setup @ictx and return 0. */
if ((key_len == le16_to_cpu(ie->key_length)) && !memcmp(key,
&ie->key, key_len)) {
ia_done:
ictx->is_in_root = FALSE;
ictx->actx = NULL;
ictx->ia = ia;
ictx->ia_vcn = vcn;
ictx->ia_na = na;
goto done;
}
/*
* Not a perfect match, need to do full blown collation so we
* know which way in the B+tree we have to go.
*/
rc = ntfs_collate(vol, cr, key, key_len, &ie->key,
le16_to_cpu(ie->key_length));
if (rc == NTFS_COLLATION_ERROR) {
ntfs_error(, "Collation error. Probably filename "
"contain invalid characters.");
err = ERANGE;
goto err_out;
}
/*
* If @key collates before the key of the current entry, there
* is definitely no such key in this index but we might need to
* descend into the B+tree so we just break out of the loop.
*/
if (rc == -1)
break;
/*
* A match should never happen as the memcmp() call should have
* caught it, but we still treat it correctly.
*/
if (!rc)
goto ia_done;
/* The keys are not equal, continue the search. */
}
/*
* We have finished with this index buffer without success. Check for
* the presence of a child node and if not present return ENOENT.
*/
if (!(ie->flags & INDEX_ENTRY_NODE)) {
ntfs_debug("Entry not found.");
err = ENOENT;
goto ia_done;
}
if ((ia->index.flags & NODE_MASK) == LEAF_NODE) {
ntfs_error(sb, "Index entry with child node found in a leaf "
"node in inode 0x%llx.", ni->mft_no);
goto err_out;
}
/* Child node present, descend into it. */
vcn = sle64_to_cpup((sle64*)((u8*)ie + le16_to_cpu(ie->length) - 8));
if (vcn >= 0)
goto descend_into_child_node;
ntfs_error(sb, "Negative child node vcn in inode 0x%llx.", ni->mft_no);
err_out:
if (na)
ntfs_attr_close(na);
if (ia)
free(ia);
if (!err)
err = EIO;
if (actx)
ntfs_attr_put_search_ctx(actx);
errno = err;
return -1;
idx_err_out:
ntfs_error(sb, "Corrupt index. Aborting lookup.");
goto err_out;
}
/**
* ntfs_index_add_filename - add filename to directory index
* @ni: ntfs inode describing directory to which index add filename
* @fn: FILE_NAME attribute to add
* @mref: reference of the inode which @fn describes
*
* NOTE: This function does not support all cases, so it can fail with
* EOPNOTSUPP error code.
*
* Return 0 on success or -1 on error with errno set to the error code.
*/
int ntfs_index_add_filename(ntfs_inode *ni, FILE_NAME_ATTR *fn, MFT_REF mref)
{
ntfs_index_context *ictx;
INDEX_ENTRY *ie;
INDEX_HEADER *ih;
int err, fn_size, ie_size, allocated_size = 0;
ntfs_debug("Entering.");
if (!ni || !fn) {
ntfs_error(, "Invalid arguments.");
errno = EINVAL;
return -1;
}
ictx = ntfs_index_ctx_get(ni, I30, 4);
if (!ictx)
return -1;
fn_size = (fn->file_name_length * sizeof(ntfschar)) +
sizeof(FILE_NAME_ATTR);
ie_size = (sizeof(INDEX_ENTRY_HEADER) + fn_size + 7) & ~7;
retry:
/* Find place where insert new entry. */
if (!ntfs_index_lookup(fn, fn_size, ictx)) {
err = EEXIST;
ntfs_error(, "Index already have such entry.");
goto err_out;
}
if (errno != ENOENT) {
err = errno;
ntfs_error(, "Failed to find place where to insert new entry.");
goto err_out;
}
/* Some setup. */
if (ictx->is_in_root)
ih = &ictx->ir->index;
else
ih = &ictx->ia->index;
if (!allocated_size)
allocated_size = le16_to_cpu(ih->allocated_size);
/* Check whether we have enough space in the index. */
if (le16_to_cpu(ih->index_length) + ie_size > allocated_size) {
/* If we in the index root try to resize it. */
if (ictx->is_in_root) {
ntfs_attr *na;
allocated_size = le16_to_cpu(ih->index_length) +
ie_size;
na = ntfs_attr_open(ictx->ni, AT_INDEX_ROOT, ictx->name,
ictx->name_len);
if (!na) {
err = errno;
ntfs_error(, "Failed to open INDEX_ROOT.");
goto err_out;
}
if (ntfs_attr_truncate(na, allocated_size + offsetof(
INDEX_ROOT, index))) {
err = EOPNOTSUPP;
ntfs_attr_close(na);
ntfs_error(, "Failed to truncate INDEX_ROOT.");
goto err_out;
}
ntfs_attr_close(na);
ntfs_index_ctx_reinit(ictx);
goto retry;
}
ntfs_debug("Not implemented case.");
err = EOPNOTSUPP;
goto err_out;
}
/* Update allocated size if we in INDEX_ROOT. */
if (ictx->is_in_root)
ih->allocated_size = cpu_to_le16(allocated_size);
/* Create entry. */
ie = calloc(1, ie_size);
if (!ie) {
err = errno;
goto err_out;
}
ie->indexed_file = cpu_to_le64(mref);
ie->length = cpu_to_le16(ie_size);
ie->key_length = cpu_to_le16(fn_size);
memcpy(&ie->key, fn, fn_size);
/* Update index length, move following entries forard and copy entry. */
ih->index_length = cpu_to_le16(le16_to_cpu(ih->index_length) + ie_size);
memmove((u8*)ictx->entry + ie_size, ictx->entry,
le16_to_cpu(ih->index_length) -
((u8*)ictx->entry - (u8*)ih) - ie_size);
memcpy(ictx->entry, ie, ie_size);
/* Done! */
ntfs_index_entry_mark_dirty(ictx);
ntfs_index_ctx_put(ictx);
free(ie);
ntfs_debug("Done.");
return 0;
err_out:
ntfs_debug("Failed.");
ntfs_index_ctx_put(ictx);
errno = err;
return -1;
}
/**
* ntfs_index_rm - remove entry from the index
* @ictx: index context describing entry to delete
*
* Delete entry described by @ictx from the index. NOTE: This function does not
* support all cases, so it can fail with EOPNOTSUPP error code. In any case
* index context is always reinitialized after use of this function, so it can
* be used for index lookup once again.
*
* Return 0 on success or -1 on error with errno set to the error code.
*/
int ntfs_index_rm(ntfs_index_context *ictx)
{
INDEX_HEADER *ih;
u32 new_index_length;
int err;
ntfs_debug("Entering.");
if (!ictx || (!ictx->ia && !ictx->ir) ||
ictx->entry->flags & INDEX_ENTRY_END) {
ntfs_error(, "Invalid arguments.");
err = EINVAL;
goto err_out;
}
if (ictx->is_in_root)
ih = &ictx->ir->index;
else
ih = &ictx->ia->index;
/* Don't support deletion of entries with subnodes yet. */
if (ictx->entry->flags & INDEX_ENTRY_NODE) {
err = EOPNOTSUPP;
goto err_out;
}
/* Calculate new length of the index. */
new_index_length = le32_to_cpu(ih->index_length) -
le16_to_cpu(ictx->entry->length);
/* Don't support deletion of the last entry in the allocation block. */
if (!ictx->is_in_root && (new_index_length <=
le32_to_cpu(ih->entries_offset) +
sizeof(INDEX_ENTRY_HEADER) + sizeof(VCN))) {
err = EOPNOTSUPP;
goto err_out;
}
/* Update index length and remove index entry. */
ih->index_length = cpu_to_le32(new_index_length);
if (ictx->is_in_root)
ih->allocated_size = ih->index_length;
memmove(ictx->entry, (u8*)ictx->entry + le16_to_cpu(
ictx->entry->length), new_index_length -
((u8*)ictx->entry - (u8*)ih));
ntfs_index_entry_mark_dirty(ictx);
/* Resize INDEX_ROOT attribute. */
if (ictx->is_in_root) {
ntfs_attr *na;
na = ntfs_attr_open(ictx->ni, AT_INDEX_ROOT, ictx->name,
ictx->name_len);
if (!na) {
err = errno;
ntfs_error(, "Failed to open INDEX_ROOT attribute. "
"Leaving inconsist metadata.");
goto err_out;
}
if (ntfs_attr_truncate(na, new_index_length + offsetof(
INDEX_ROOT, index))) {
err = errno;
ntfs_error(, "Failed to truncate INDEX_ROOT attribute. "
" Leaving inconsist metadata.");
goto err_out;
}
ntfs_attr_close(na);
}
ntfs_index_ctx_reinit(ictx);
ntfs_debug("Done.");
return 0;
err_out:
ntfs_index_ctx_reinit(ictx);
ntfs_debug("Failed.");
errno = err;
return -1;
}
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