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linuxdebug/fs/ntfs/dir.c

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null pointer error
2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0-or-later
/**
* dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project.
*
* Copyright (c) 2001-2007 Anton Altaparmakov
* Copyright (c) 2002 Richard Russon
*/
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include "dir.h"
#include "aops.h"
#include "attrib.h"
#include "mft.h"
#include "debug.h"
#include "ntfs.h"
/**
* The little endian Unicode string $I30 as a global constant.
*/
ntfschar I30[5] = { cpu_to_le16('$'), cpu_to_le16('I'),
cpu_to_le16('3'), cpu_to_le16('0'), 0 };
/**
* ntfs_lookup_inode_by_name - find an inode in a directory given its name
* @dir_ni: ntfs inode of the directory in which to search for the name
* @uname: Unicode name for which to search in the directory
* @uname_len: length of the name @uname in Unicode characters
* @res: return the found file name if necessary (see below)
*
* Look for an inode with name @uname in the directory with inode @dir_ni.
* ntfs_lookup_inode_by_name() walks the contents of the directory looking for
* the Unicode name. If the name is found in the directory, the corresponding
* inode number (>= 0) is returned as a mft reference in cpu format, i.e. it
* is a 64-bit number containing the sequence number.
*
* On error, a negative value is returned corresponding to the error code. In
* particular if the inode is not found -ENOENT is returned. Note that you
* can't just check the return value for being negative, you have to check the
* inode number for being negative which you can extract using MREC(return
* value).
*
* Note, @uname_len does not include the (optional) terminating NULL character.
*
* Note, we look for a case sensitive match first but we also look for a case
* insensitive match at the same time. If we find a case insensitive match, we
* save that for the case that we don't find an exact match, where we return
* the case insensitive match and setup @res (which we allocate!) with the mft
* reference, the file name type, length and with a copy of the little endian
* Unicode file name itself. If we match a file name which is in the DOS name
* space, we only return the mft reference and file name type in @res.
* ntfs_lookup() then uses this to find the long file name in the inode itself.
* This is to avoid polluting the dcache with short file names. We want them to
* work but we don't care for how quickly one can access them. This also fixes
* the dcache aliasing issues.
*
* Locking: - Caller must hold i_mutex on the directory.
* - Each page cache page in the index allocation mapping must be
* locked whilst being accessed otherwise we may find a corrupt
* page due to it being under ->writepage at the moment which
* applies the mst protection fixups before writing out and then
* removes them again after the write is complete after which it
* unlocks the page.
*/
MFT_REF ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname,
const int uname_len, ntfs_name **res)
{
ntfs_volume *vol = dir_ni->vol;
struct super_block *sb = vol->sb;
MFT_RECORD *m;
INDEX_ROOT *ir;
INDEX_ENTRY *ie;
INDEX_ALLOCATION *ia;
u8 *index_end;
u64 mref;
ntfs_attr_search_ctx *ctx;
int err, rc;
VCN vcn, old_vcn;
struct address_space *ia_mapping;
struct page *page;
u8 *kaddr;
ntfs_name *name = NULL;
BUG_ON(!S_ISDIR(VFS_I(dir_ni)->i_mode));
BUG_ON(NInoAttr(dir_ni));
/* Get hold of the mft record for the directory. */
m = map_mft_record(dir_ni);
if (IS_ERR(m)) {
ntfs_error(sb, "map_mft_record() failed with error code %ld.",
-PTR_ERR(m));
return ERR_MREF(PTR_ERR(m));
}
ctx = ntfs_attr_get_search_ctx(dir_ni, m);
if (unlikely(!ctx)) {
err = -ENOMEM;
goto err_out;
}
/* Find the index root attribute in the mft record. */
err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL,
0, ctx);
if (unlikely(err)) {
if (err == -ENOENT) {
ntfs_error(sb, "Index root attribute missing in "
"directory inode 0x%lx.",
dir_ni->mft_no);
err = -EIO;
}
goto err_out;
}
/* Get to the index root value (it's been verified in read_inode). */
ir = (INDEX_ROOT*)((u8*)ctx->attr +
le16_to_cpu(ctx->attr->data.resident.value_offset));
index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
/* 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*)ctx->mrec || (u8*)ie +
sizeof(INDEX_ENTRY_HEADER) > index_end ||
(u8*)ie + le16_to_cpu(ie->key_length) >
index_end)
goto dir_err_out;
/*
* The last entry cannot contain a name. 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;
/*
* We perform a case sensitive comparison and if that matches
* we are done and return the mft reference of the inode (i.e.
* the inode number together with the sequence number for
* consistency checking). We convert it to cpu format before
* returning.
*/
if (ntfs_are_names_equal(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length,
CASE_SENSITIVE, vol->upcase, vol->upcase_len)) {
found_it:
/*
* We have a perfect match, so we don't need to care
* about having matched imperfectly before, so we can
* free name and set *res to NULL.
* However, if the perfect match is a short file name,
* we need to signal this through *res, so that
* ntfs_lookup() can fix dcache aliasing issues.
* As an optimization we just reuse an existing
* allocation of *res.
*/
if (ie->key.file_name.file_name_type == FILE_NAME_DOS) {
if (!name) {
name = kmalloc(sizeof(ntfs_name),
GFP_NOFS);
if (!name) {
err = -ENOMEM;
goto err_out;
}
}
name->mref = le64_to_cpu(
ie->data.dir.indexed_file);
name->type = FILE_NAME_DOS;
name->len = 0;
*res = name;
} else {
kfree(name);
*res = NULL;
}
mref = le64_to_cpu(ie->data.dir.indexed_file);
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(dir_ni);
return mref;
}
/*
* For a case insensitive mount, we also perform a case
* insensitive comparison (provided the file name is not in the
* POSIX namespace). If the comparison matches, and the name is
* in the WIN32 namespace, we cache the filename in *res so
* that the caller, ntfs_lookup(), can work on it. If the
* comparison matches, and the name is in the DOS namespace, we
* only cache the mft reference and the file name type (we set
* the name length to zero for simplicity).
*/
if (!NVolCaseSensitive(vol) &&
ie->key.file_name.file_name_type &&
ntfs_are_names_equal(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length,
IGNORE_CASE, vol->upcase, vol->upcase_len)) {
int name_size = sizeof(ntfs_name);
u8 type = ie->key.file_name.file_name_type;
u8 len = ie->key.file_name.file_name_length;
/* Only one case insensitive matching name allowed. */
if (name) {
ntfs_error(sb, "Found already allocated name "
"in phase 1. Please run chkdsk "
"and if that doesn't find any "
"errors please report you saw "
"this message to "
"linux-ntfs-dev@lists."
"sourceforge.net.");
goto dir_err_out;
}
if (type != FILE_NAME_DOS)
name_size += len * sizeof(ntfschar);
name = kmalloc(name_size, GFP_NOFS);
if (!name) {
err = -ENOMEM;
goto err_out;
}
name->mref = le64_to_cpu(ie->data.dir.indexed_file);
name->type = type;
if (type != FILE_NAME_DOS) {
name->len = len;
memcpy(name->name, ie->key.file_name.file_name,
len * sizeof(ntfschar));
} else
name->len = 0;
*res = name;
}
/*
* 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_names(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, 1,
IGNORE_CASE, vol->upcase, vol->upcase_len);
/*
* If uname collates before the name of the current entry, there
* is definitely no such name 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;
/* The names are not equal, continue the search. */
if (rc)
continue;
/*
* Names match with case insensitive comparison, now try the
* case sensitive comparison, which is required for proper
* collation.
*/
rc = ntfs_collate_names(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, 1,
CASE_SENSITIVE, vol->upcase, vol->upcase_len);
if (rc == -1)
break;
if (rc)
continue;
/*
* Perfect match, this will never happen as the
* ntfs_are_names_equal() call will have gotten a match but we
* still treat it correctly.
*/
goto found_it;
}
/*
* We have finished with this index without success. Check for the
* presence of a child node and if not present return -ENOENT, unless
* we have got a matching name cached in name in which case return the
* mft reference associated with it.
*/
if (!(ie->flags & INDEX_ENTRY_NODE)) {
if (name) {
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(dir_ni);
return name->mref;
}
ntfs_debug("Entry not found.");
err = -ENOENT;
goto err_out;
} /* Child node present, descend into it. */
/* Consistency check: Verify that an index allocation exists. */
if (!NInoIndexAllocPresent(dir_ni)) {
ntfs_error(sb, "No index allocation attribute but index entry "
"requires one. Directory inode 0x%lx is "
"corrupt or driver bug.", dir_ni->mft_no);
goto err_out;
}
/* 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));
ia_mapping = VFS_I(dir_ni)->i_mapping;
/*
* We are done with the index root and the mft record. Release them,
* otherwise we deadlock with ntfs_map_page().
*/
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(dir_ni);
m = NULL;
ctx = NULL;
descend_into_child_node:
/*
* Convert vcn to index into the index allocation attribute in units
* of PAGE_SIZE and map the page cache page, reading it from
* disk if necessary.
*/
page = ntfs_map_page(ia_mapping, vcn <<
dir_ni->itype.index.vcn_size_bits >> PAGE_SHIFT);
if (IS_ERR(page)) {
ntfs_error(sb, "Failed to map directory index page, error %ld.",
-PTR_ERR(page));
err = PTR_ERR(page);
goto err_out;
}
lock_page(page);
kaddr = (u8*)page_address(page);
fast_descend_into_child_node:
/* Get to the index allocation block. */
ia = (INDEX_ALLOCATION*)(kaddr + ((vcn <<
dir_ni->itype.index.vcn_size_bits) & ~PAGE_MASK));
/* Bounds checks. */
if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE) {
ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
"inode 0x%lx or driver bug.", dir_ni->mft_no);
goto unm_err_out;
}
/* Catch multi sector transfer fixup errors. */
if (unlikely(!ntfs_is_indx_record(ia->magic))) {
ntfs_error(sb, "Directory index record with vcn 0x%llx is "
"corrupt. Corrupt inode 0x%lx. Run chkdsk.",
(unsigned long long)vcn, dir_ni->mft_no);
goto unm_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). "
"Directory inode 0x%lx is corrupt or driver "
"bug.", (unsigned long long)
sle64_to_cpu(ia->index_block_vcn),
(unsigned long long)vcn, dir_ni->mft_no);
goto unm_err_out;
}
if (le32_to_cpu(ia->index.allocated_size) + 0x18 !=
dir_ni->itype.index.block_size) {
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
"0x%lx has a size (%u) differing from the "
"directory specified size (%u). Directory "
"inode is corrupt or driver bug.",
(unsigned long long)vcn, dir_ni->mft_no,
le32_to_cpu(ia->index.allocated_size) + 0x18,
dir_ni->itype.index.block_size);
goto unm_err_out;
}
index_end = (u8*)ia + dir_ni->itype.index.block_size;
if (index_end > kaddr + PAGE_SIZE) {
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
"0x%lx crosses page boundary. Impossible! "
"Cannot access! This is probably a bug in the "
"driver.", (unsigned long long)vcn,
dir_ni->mft_no);
goto unm_err_out;
}
index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
if (index_end > (u8*)ia + dir_ni->itype.index.block_size) {
ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory "
"inode 0x%lx exceeds maximum size.",
(unsigned long long)vcn, dir_ni->mft_no);
goto unm_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 check. */
if ((u8*)ie < (u8*)ia || (u8*)ie +
sizeof(INDEX_ENTRY_HEADER) > index_end ||
(u8*)ie + le16_to_cpu(ie->key_length) >
index_end) {
ntfs_error(sb, "Index entry out of bounds in "
"directory inode 0x%lx.",
dir_ni->mft_no);
goto unm_err_out;
}
/*
* The last entry cannot contain a name. 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;
/*
* We perform a case sensitive comparison and if that matches
* we are done and return the mft reference of the inode (i.e.
* the inode number together with the sequence number for
* consistency checking). We convert it to cpu format before
* returning.
*/
if (ntfs_are_names_equal(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length,
CASE_SENSITIVE, vol->upcase, vol->upcase_len)) {
found_it2:
/*
* We have a perfect match, so we don't need to care
* about having matched imperfectly before, so we can
* free name and set *res to NULL.
* However, if the perfect match is a short file name,
* we need to signal this through *res, so that
* ntfs_lookup() can fix dcache aliasing issues.
* As an optimization we just reuse an existing
* allocation of *res.
*/
if (ie->key.file_name.file_name_type == FILE_NAME_DOS) {
if (!name) {
name = kmalloc(sizeof(ntfs_name),
GFP_NOFS);
if (!name) {
err = -ENOMEM;
goto unm_err_out;
}
}
name->mref = le64_to_cpu(
ie->data.dir.indexed_file);
name->type = FILE_NAME_DOS;
name->len = 0;
*res = name;
} else {
kfree(name);
*res = NULL;
}
mref = le64_to_cpu(ie->data.dir.indexed_file);
unlock_page(page);
ntfs_unmap_page(page);
return mref;
}
/*
* For a case insensitive mount, we also perform a case
* insensitive comparison (provided the file name is not in the
* POSIX namespace). If the comparison matches, and the name is
* in the WIN32 namespace, we cache the filename in *res so
* that the caller, ntfs_lookup(), can work on it. If the
* comparison matches, and the name is in the DOS namespace, we
* only cache the mft reference and the file name type (we set
* the name length to zero for simplicity).
*/
if (!NVolCaseSensitive(vol) &&
ie->key.file_name.file_name_type &&
ntfs_are_names_equal(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length,
IGNORE_CASE, vol->upcase, vol->upcase_len)) {
int name_size = sizeof(ntfs_name);
u8 type = ie->key.file_name.file_name_type;
u8 len = ie->key.file_name.file_name_length;
/* Only one case insensitive matching name allowed. */
if (name) {
ntfs_error(sb, "Found already allocated name "
"in phase 2. Please run chkdsk "
"and if that doesn't find any "
"errors please report you saw "
"this message to "
"linux-ntfs-dev@lists."
"sourceforge.net.");
unlock_page(page);
ntfs_unmap_page(page);
goto dir_err_out;
}
if (type != FILE_NAME_DOS)
name_size += len * sizeof(ntfschar);
name = kmalloc(name_size, GFP_NOFS);
if (!name) {
err = -ENOMEM;
goto unm_err_out;
}
name->mref = le64_to_cpu(ie->data.dir.indexed_file);
name->type = type;
if (type != FILE_NAME_DOS) {
name->len = len;
memcpy(name->name, ie->key.file_name.file_name,
len * sizeof(ntfschar));
} else
name->len = 0;
*res = name;
}
/*
* 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_names(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, 1,
IGNORE_CASE, vol->upcase, vol->upcase_len);
/*
* If uname collates before the name of the current entry, there
* is definitely no such name 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;
/* The names are not equal, continue the search. */
if (rc)
continue;
/*
* Names match with case insensitive comparison, now try the
* case sensitive comparison, which is required for proper
* collation.
*/
rc = ntfs_collate_names(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, 1,
CASE_SENSITIVE, vol->upcase, vol->upcase_len);
if (rc == -1)
break;
if (rc)
continue;
/*
* Perfect match, this will never happen as the
* ntfs_are_names_equal() call will have gotten a match but we
* still treat it correctly.
*/
goto found_it2;
}
/*
* We have finished with this index buffer without success. Check for
* the presence of a child node.
*/
if (ie->flags & INDEX_ENTRY_NODE) {
if ((ia->index.flags & NODE_MASK) == LEAF_NODE) {
ntfs_error(sb, "Index entry with child node found in "
"a leaf node in directory inode 0x%lx.",
dir_ni->mft_no);
goto unm_err_out;
}
/* Child node present, descend into it. */
old_vcn = vcn;
vcn = sle64_to_cpup((sle64*)((u8*)ie +
le16_to_cpu(ie->length) - 8));
if (vcn >= 0) {
/* If vcn is in the same page cache page as old_vcn we
* recycle the mapped page. */
if (old_vcn << vol->cluster_size_bits >>
PAGE_SHIFT == vcn <<
vol->cluster_size_bits >>
PAGE_SHIFT)
goto fast_descend_into_child_node;
unlock_page(page);
ntfs_unmap_page(page);
goto descend_into_child_node;
}
ntfs_error(sb, "Negative child node vcn in directory inode "
"0x%lx.", dir_ni->mft_no);
goto unm_err_out;
}
/*
* No child node present, return -ENOENT, unless we have got a matching
* name cached in name in which case return the mft reference
* associated with it.
*/
if (name) {
unlock_page(page);
ntfs_unmap_page(page);
return name->mref;
}
ntfs_debug("Entry not found.");
err = -ENOENT;
unm_err_out:
unlock_page(page);
ntfs_unmap_page(page);
err_out:
if (!err)
err = -EIO;
if (ctx)
ntfs_attr_put_search_ctx(ctx);
if (m)
unmap_mft_record(dir_ni);
if (name) {
kfree(name);
*res = NULL;
}
return ERR_MREF(err);
dir_err_out:
ntfs_error(sb, "Corrupt directory. Aborting lookup.");
goto err_out;
}
#if 0
// TODO: (AIA)
// The algorithm embedded in this code will be required for the time when we
// want to support adding of entries to directories, where we require correct
// collation of file names in order not to cause corruption of the filesystem.
/**
* ntfs_lookup_inode_by_name - find an inode in a directory given its name
* @dir_ni: ntfs inode of the directory in which to search for the name
* @uname: Unicode name for which to search in the directory
* @uname_len: length of the name @uname in Unicode characters
*
* Look for an inode with name @uname in the directory with inode @dir_ni.
* ntfs_lookup_inode_by_name() walks the contents of the directory looking for
* the Unicode name. If the name is found in the directory, the corresponding
* inode number (>= 0) is returned as a mft reference in cpu format, i.e. it
* is a 64-bit number containing the sequence number.
*
* On error, a negative value is returned corresponding to the error code. In
* particular if the inode is not found -ENOENT is returned. Note that you
* can't just check the return value for being negative, you have to check the
* inode number for being negative which you can extract using MREC(return
* value).
*
* Note, @uname_len does not include the (optional) terminating NULL character.
*/
u64 ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname,
const int uname_len)
{
ntfs_volume *vol = dir_ni->vol;
struct super_block *sb = vol->sb;
MFT_RECORD *m;
INDEX_ROOT *ir;
INDEX_ENTRY *ie;
INDEX_ALLOCATION *ia;
u8 *index_end;
u64 mref;
ntfs_attr_search_ctx *ctx;
int err, rc;
IGNORE_CASE_BOOL ic;
VCN vcn, old_vcn;
struct address_space *ia_mapping;
struct page *page;
u8 *kaddr;
/* Get hold of the mft record for the directory. */
m = map_mft_record(dir_ni);
if (IS_ERR(m)) {
ntfs_error(sb, "map_mft_record() failed with error code %ld.",
-PTR_ERR(m));
return ERR_MREF(PTR_ERR(m));
}
ctx = ntfs_attr_get_search_ctx(dir_ni, m);
if (!ctx) {
err = -ENOMEM;
goto err_out;
}
/* Find the index root attribute in the mft record. */
err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL,
0, ctx);
if (unlikely(err)) {
if (err == -ENOENT) {
ntfs_error(sb, "Index root attribute missing in "
"directory inode 0x%lx.",
dir_ni->mft_no);
err = -EIO;
}
goto err_out;
}
/* Get to the index root value (it's been verified in read_inode). */
ir = (INDEX_ROOT*)((u8*)ctx->attr +
le16_to_cpu(ctx->attr->data.resident.value_offset));
index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
/* 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*)ctx->mrec || (u8*)ie +
sizeof(INDEX_ENTRY_HEADER) > index_end ||
(u8*)ie + le16_to_cpu(ie->key_length) >
index_end)
goto dir_err_out;
/*
* The last entry cannot contain a name. 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 current entry has a name type of POSIX, the name is
* case sensitive and not otherwise. This has the effect of us
* not being able to access any POSIX file names which collate
* after the non-POSIX one when they only differ in case, but
* anyone doing screwy stuff like that deserves to burn in
* hell... Doing that kind of stuff on NT4 actually causes
* corruption on the partition even when using SP6a and Linux
* is not involved at all.
*/
ic = ie->key.file_name.file_name_type ? IGNORE_CASE :
CASE_SENSITIVE;
/*
* If the names match perfectly, we are done and return the
* mft reference of the inode (i.e. the inode number together
* with the sequence number for consistency checking. We
* convert it to cpu format before returning.
*/
if (ntfs_are_names_equal(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, ic,
vol->upcase, vol->upcase_len)) {
found_it:
mref = le64_to_cpu(ie->data.dir.indexed_file);
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(dir_ni);
return mref;
}
/*
* 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_names(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, 1,
IGNORE_CASE, vol->upcase, vol->upcase_len);
/*
* If uname collates before the name of the current entry, there
* is definitely no such name 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;
/* The names are not equal, continue the search. */
if (rc)
continue;
/*
* Names match with case insensitive comparison, now try the
* case sensitive comparison, which is required for proper
* collation.
*/
rc = ntfs_collate_names(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, 1,
CASE_SENSITIVE, vol->upcase, vol->upcase_len);
if (rc == -1)
break;
if (rc)
continue;
/*
* Perfect match, this will never happen as the
* ntfs_are_names_equal() call will have gotten a match but we
* still treat it correctly.
*/
goto found_it;
}
/*
* We have finished with this index without success. Check for the
* presence of a child node.
*/
if (!(ie->flags & INDEX_ENTRY_NODE)) {
/* No child node, return -ENOENT. */
err = -ENOENT;
goto err_out;
} /* Child node present, descend into it. */
/* Consistency check: Verify that an index allocation exists. */
if (!NInoIndexAllocPresent(dir_ni)) {
ntfs_error(sb, "No index allocation attribute but index entry "
"requires one. Directory inode 0x%lx is "
"corrupt or driver bug.", dir_ni->mft_no);
goto err_out;
}
/* Get the starting vcn of the index_block holding the child node. */
vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8);
ia_mapping = VFS_I(dir_ni)->i_mapping;
/*
* We are done with the index root and the mft record. Release them,
* otherwise we deadlock with ntfs_map_page().
*/
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(dir_ni);
m = NULL;
ctx = NULL;
descend_into_child_node:
/*
* Convert vcn to index into the index allocation attribute in units
* of PAGE_SIZE and map the page cache page, reading it from
* disk if necessary.
*/
page = ntfs_map_page(ia_mapping, vcn <<
dir_ni->itype.index.vcn_size_bits >> PAGE_SHIFT);
if (IS_ERR(page)) {
ntfs_error(sb, "Failed to map directory index page, error %ld.",
-PTR_ERR(page));
err = PTR_ERR(page);
goto err_out;
}
lock_page(page);
kaddr = (u8*)page_address(page);
fast_descend_into_child_node:
/* Get to the index allocation block. */
ia = (INDEX_ALLOCATION*)(kaddr + ((vcn <<
dir_ni->itype.index.vcn_size_bits) & ~PAGE_MASK));
/* Bounds checks. */
if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE) {
ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
"inode 0x%lx or driver bug.", dir_ni->mft_no);
goto unm_err_out;
}
/* Catch multi sector transfer fixup errors. */
if (unlikely(!ntfs_is_indx_record(ia->magic))) {
ntfs_error(sb, "Directory index record with vcn 0x%llx is "
"corrupt. Corrupt inode 0x%lx. Run chkdsk.",
(unsigned long long)vcn, dir_ni->mft_no);
goto unm_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). "
"Directory inode 0x%lx is corrupt or driver "
"bug.", (unsigned long long)
sle64_to_cpu(ia->index_block_vcn),
(unsigned long long)vcn, dir_ni->mft_no);
goto unm_err_out;
}
if (le32_to_cpu(ia->index.allocated_size) + 0x18 !=
dir_ni->itype.index.block_size) {
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
"0x%lx has a size (%u) differing from the "
"directory specified size (%u). Directory "
"inode is corrupt or driver bug.",
(unsigned long long)vcn, dir_ni->mft_no,
le32_to_cpu(ia->index.allocated_size) + 0x18,
dir_ni->itype.index.block_size);
goto unm_err_out;
}
index_end = (u8*)ia + dir_ni->itype.index.block_size;
if (index_end > kaddr + PAGE_SIZE) {
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
"0x%lx crosses page boundary. Impossible! "
"Cannot access! This is probably a bug in the "
"driver.", (unsigned long long)vcn,
dir_ni->mft_no);
goto unm_err_out;
}
index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
if (index_end > (u8*)ia + dir_ni->itype.index.block_size) {
ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory "
"inode 0x%lx exceeds maximum size.",
(unsigned long long)vcn, dir_ni->mft_no);
goto unm_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 check. */
if ((u8*)ie < (u8*)ia || (u8*)ie +
sizeof(INDEX_ENTRY_HEADER) > index_end ||
(u8*)ie + le16_to_cpu(ie->key_length) >
index_end) {
ntfs_error(sb, "Index entry out of bounds in "
"directory inode 0x%lx.",
dir_ni->mft_no);
goto unm_err_out;
}
/*
* The last entry cannot contain a name. 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 current entry has a name type of POSIX, the name is
* case sensitive and not otherwise. This has the effect of us
* not being able to access any POSIX file names which collate
* after the non-POSIX one when they only differ in case, but
* anyone doing screwy stuff like that deserves to burn in
* hell... Doing that kind of stuff on NT4 actually causes
* corruption on the partition even when using SP6a and Linux
* is not involved at all.
*/
ic = ie->key.file_name.file_name_type ? IGNORE_CASE :
CASE_SENSITIVE;
/*
* If the names match perfectly, we are done and return the
* mft reference of the inode (i.e. the inode number together
* with the sequence number for consistency checking. We
* convert it to cpu format before returning.
*/
if (ntfs_are_names_equal(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, ic,
vol->upcase, vol->upcase_len)) {
found_it2:
mref = le64_to_cpu(ie->data.dir.indexed_file);
unlock_page(page);
ntfs_unmap_page(page);
return mref;
}
/*
* 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_names(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, 1,
IGNORE_CASE, vol->upcase, vol->upcase_len);
/*
* If uname collates before the name of the current entry, there
* is definitely no such name 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;
/* The names are not equal, continue the search. */
if (rc)
continue;
/*
* Names match with case insensitive comparison, now try the
* case sensitive comparison, which is required for proper
* collation.
*/
rc = ntfs_collate_names(uname, uname_len,
(ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, 1,
CASE_SENSITIVE, vol->upcase, vol->upcase_len);
if (rc == -1)
break;
if (rc)
continue;
/*
* Perfect match, this will never happen as the
* ntfs_are_names_equal() call will have gotten a match but we
* still treat it correctly.
*/
goto found_it2;
}
/*
* We have finished with this index buffer without success. Check for
* the presence of a child node.
*/
if (ie->flags & INDEX_ENTRY_NODE) {
if ((ia->index.flags & NODE_MASK) == LEAF_NODE) {
ntfs_error(sb, "Index entry with child node found in "
"a leaf node in directory inode 0x%lx.",
dir_ni->mft_no);
goto unm_err_out;
}
/* Child node present, descend into it. */
old_vcn = vcn;
vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8);
if (vcn >= 0) {
/* If vcn is in the same page cache page as old_vcn we
* recycle the mapped page. */
if (old_vcn << vol->cluster_size_bits >>
PAGE_SHIFT == vcn <<
vol->cluster_size_bits >>
PAGE_SHIFT)
goto fast_descend_into_child_node;
unlock_page(page);
ntfs_unmap_page(page);
goto descend_into_child_node;
}
ntfs_error(sb, "Negative child node vcn in directory inode "
"0x%lx.", dir_ni->mft_no);
goto unm_err_out;
}
/* No child node, return -ENOENT. */
ntfs_debug("Entry not found.");
err = -ENOENT;
unm_err_out:
unlock_page(page);
ntfs_unmap_page(page);
err_out:
if (!err)
err = -EIO;
if (ctx)
ntfs_attr_put_search_ctx(ctx);
if (m)
unmap_mft_record(dir_ni);
return ERR_MREF(err);
dir_err_out:
ntfs_error(sb, "Corrupt directory. Aborting lookup.");
goto err_out;
}
#endif
/**
* ntfs_filldir - ntfs specific filldir method
* @vol: current ntfs volume
* @ndir: ntfs inode of current directory
* @ia_page: page in which the index allocation buffer @ie is in resides
* @ie: current index entry
* @name: buffer to use for the converted name
* @actor: what to feed the entries to
*
* Convert the Unicode @name to the loaded NLS and pass it to the @filldir
* callback.
*
* If @ia_page is not NULL it is the locked page containing the index
* allocation block containing the index entry @ie.
*
* Note, we drop (and then reacquire) the page lock on @ia_page across the
* @filldir() call otherwise we would deadlock with NFSd when it calls ->lookup
* since ntfs_lookup() will lock the same page. As an optimization, we do not
* retake the lock if we are returning a non-zero value as ntfs_readdir()
* would need to drop the lock immediately anyway.
*/
static inline int ntfs_filldir(ntfs_volume *vol,
ntfs_inode *ndir, struct page *ia_page, INDEX_ENTRY *ie,
u8 *name, struct dir_context *actor)
{
unsigned long mref;
int name_len;
unsigned dt_type;
FILE_NAME_TYPE_FLAGS name_type;
name_type = ie->key.file_name.file_name_type;
if (name_type == FILE_NAME_DOS) {
ntfs_debug("Skipping DOS name space entry.");
return 0;
}
if (MREF_LE(ie->data.dir.indexed_file) == FILE_root) {
ntfs_debug("Skipping root directory self reference entry.");
return 0;
}
if (MREF_LE(ie->data.dir.indexed_file) < FILE_first_user &&
!NVolShowSystemFiles(vol)) {
ntfs_debug("Skipping system file.");
return 0;
}
name_len = ntfs_ucstonls(vol, (ntfschar*)&ie->key.file_name.file_name,
ie->key.file_name.file_name_length, &name,
NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1);
if (name_len <= 0) {
ntfs_warning(vol->sb, "Skipping unrepresentable inode 0x%llx.",
(long long)MREF_LE(ie->data.dir.indexed_file));
return 0;
}
if (ie->key.file_name.file_attributes &
FILE_ATTR_DUP_FILE_NAME_INDEX_PRESENT)
dt_type = DT_DIR;
else
dt_type = DT_REG;
mref = MREF_LE(ie->data.dir.indexed_file);
/*
* Drop the page lock otherwise we deadlock with NFS when it calls
* ->lookup since ntfs_lookup() will lock the same page.
*/
if (ia_page)
unlock_page(ia_page);
ntfs_debug("Calling filldir for %s with len %i, fpos 0x%llx, inode "
"0x%lx, DT_%s.", name, name_len, actor->pos, mref,
dt_type == DT_DIR ? "DIR" : "REG");
if (!dir_emit(actor, name, name_len, mref, dt_type))
return 1;
/* Relock the page but not if we are aborting ->readdir. */
if (ia_page)
lock_page(ia_page);
return 0;
}
/*
* We use the same basic approach as the old NTFS driver, i.e. we parse the
* index root entries and then the index allocation entries that are marked
* as in use in the index bitmap.
*
* While this will return the names in random order this doesn't matter for
* ->readdir but OTOH results in a faster ->readdir.
*
* VFS calls ->readdir without BKL but with i_mutex held. This protects the VFS
* parts (e.g. ->f_pos and ->i_size, and it also protects against directory
* modifications).
*
* Locking: - Caller must hold i_mutex on the directory.
* - Each page cache page in the index allocation mapping must be
* locked whilst being accessed otherwise we may find a corrupt
* page due to it being under ->writepage at the moment which
* applies the mst protection fixups before writing out and then
* removes them again after the write is complete after which it
* unlocks the page.
*/
static int ntfs_readdir(struct file *file, struct dir_context *actor)
{
s64 ia_pos, ia_start, prev_ia_pos, bmp_pos;
loff_t i_size;
struct inode *bmp_vi, *vdir = file_inode(file);
struct super_block *sb = vdir->i_sb;
ntfs_inode *ndir = NTFS_I(vdir);
ntfs_volume *vol = NTFS_SB(sb);
MFT_RECORD *m;
INDEX_ROOT *ir = NULL;
INDEX_ENTRY *ie;
INDEX_ALLOCATION *ia;
u8 *name = NULL;
int rc, err, ir_pos, cur_bmp_pos;
struct address_space *ia_mapping, *bmp_mapping;
struct page *bmp_page = NULL, *ia_page = NULL;
u8 *kaddr, *bmp, *index_end;
ntfs_attr_search_ctx *ctx;
ntfs_debug("Entering for inode 0x%lx, fpos 0x%llx.",
vdir->i_ino, actor->pos);
rc = err = 0;
/* Are we at end of dir yet? */
i_size = i_size_read(vdir);
if (actor->pos >= i_size + vol->mft_record_size)
return 0;
/* Emulate . and .. for all directories. */
if (!dir_emit_dots(file, actor))
return 0;
m = NULL;
ctx = NULL;
/*
* Allocate a buffer to store the current name being processed
* converted to format determined by current NLS.
*/
name = kmalloc(NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1, GFP_NOFS);
if (unlikely(!name)) {
err = -ENOMEM;
goto err_out;
}
/* Are we jumping straight into the index allocation attribute? */
if (actor->pos >= vol->mft_record_size)
goto skip_index_root;
/* Get hold of the mft record for the directory. */
m = map_mft_record(ndir);
if (IS_ERR(m)) {
err = PTR_ERR(m);
m = NULL;
goto err_out;
}
ctx = ntfs_attr_get_search_ctx(ndir, m);
if (unlikely(!ctx)) {
err = -ENOMEM;
goto err_out;
}
/* Get the offset into the index root attribute. */
ir_pos = (s64)actor->pos;
/* Find the index root attribute in the mft record. */
err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL,
0, ctx);
if (unlikely(err)) {
ntfs_error(sb, "Index root attribute missing in directory "
"inode 0x%lx.", vdir->i_ino);
goto err_out;
}
/*
* Copy the index root attribute value to a buffer so that we can put
* the search context and unmap the mft record before calling the
* filldir() callback. We need to do this because of NFSd which calls
* ->lookup() from its filldir callback() and this causes NTFS to
* deadlock as ntfs_lookup() maps the mft record of the directory and
* we have got it mapped here already. The only solution is for us to
* unmap the mft record here so that a call to ntfs_lookup() is able to
* map the mft record without deadlocking.
*/
rc = le32_to_cpu(ctx->attr->data.resident.value_length);
ir = kmalloc(rc, GFP_NOFS);
if (unlikely(!ir)) {
err = -ENOMEM;
goto err_out;
}
/* Copy the index root value (it has been verified in read_inode). */
memcpy(ir, (u8*)ctx->attr +
le16_to_cpu(ctx->attr->data.resident.value_offset), rc);
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(ndir);
ctx = NULL;
m = NULL;
index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
/* 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 or until filldir tells us it has had enough
* or signals an error (both covered by the rc test).
*/
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
ntfs_debug("In index root, offset 0x%zx.", (u8*)ie - (u8*)ir);
/* Bounds checks. */
if (unlikely((u8*)ie < (u8*)ir || (u8*)ie +
sizeof(INDEX_ENTRY_HEADER) > index_end ||
(u8*)ie + le16_to_cpu(ie->key_length) >
index_end))
goto err_out;
/* The last entry cannot contain a name. */
if (ie->flags & INDEX_ENTRY_END)
break;
/* Skip index root entry if continuing previous readdir. */
if (ir_pos > (u8*)ie - (u8*)ir)
continue;
/* Advance the position even if going to skip the entry. */
actor->pos = (u8*)ie - (u8*)ir;
/* Submit the name to the filldir callback. */
rc = ntfs_filldir(vol, ndir, NULL, ie, name, actor);
if (rc) {
kfree(ir);
goto abort;
}
}
/* We are done with the index root and can free the buffer. */
kfree(ir);
ir = NULL;
/* If there is no index allocation attribute we are finished. */
if (!NInoIndexAllocPresent(ndir))
goto EOD;
/* Advance fpos to the beginning of the index allocation. */
actor->pos = vol->mft_record_size;
skip_index_root:
kaddr = NULL;
prev_ia_pos = -1LL;
/* Get the offset into the index allocation attribute. */
ia_pos = (s64)actor->pos - vol->mft_record_size;
ia_mapping = vdir->i_mapping;
ntfs_debug("Inode 0x%lx, getting index bitmap.", vdir->i_ino);
bmp_vi = ntfs_attr_iget(vdir, AT_BITMAP, I30, 4);
if (IS_ERR(bmp_vi)) {
ntfs_error(sb, "Failed to get bitmap attribute.");
err = PTR_ERR(bmp_vi);
goto err_out;
}
bmp_mapping = bmp_vi->i_mapping;
/* Get the starting bitmap bit position and sanity check it. */
bmp_pos = ia_pos >> ndir->itype.index.block_size_bits;
if (unlikely(bmp_pos >> 3 >= i_size_read(bmp_vi))) {
ntfs_error(sb, "Current index allocation position exceeds "
"index bitmap size.");
goto iput_err_out;
}
/* Get the starting bit position in the current bitmap page. */
cur_bmp_pos = bmp_pos & ((PAGE_SIZE * 8) - 1);
bmp_pos &= ~(u64)((PAGE_SIZE * 8) - 1);
get_next_bmp_page:
ntfs_debug("Reading bitmap with page index 0x%llx, bit ofs 0x%llx",
(unsigned long long)bmp_pos >> (3 + PAGE_SHIFT),
(unsigned long long)bmp_pos &
(unsigned long long)((PAGE_SIZE * 8) - 1));
bmp_page = ntfs_map_page(bmp_mapping,
bmp_pos >> (3 + PAGE_SHIFT));
if (IS_ERR(bmp_page)) {
ntfs_error(sb, "Reading index bitmap failed.");
err = PTR_ERR(bmp_page);
bmp_page = NULL;
goto iput_err_out;
}
bmp = (u8*)page_address(bmp_page);
/* Find next index block in use. */
while (!(bmp[cur_bmp_pos >> 3] & (1 << (cur_bmp_pos & 7)))) {
find_next_index_buffer:
cur_bmp_pos++;
/*
* If we have reached the end of the bitmap page, get the next
* page, and put away the old one.
*/
if (unlikely((cur_bmp_pos >> 3) >= PAGE_SIZE)) {
ntfs_unmap_page(bmp_page);
bmp_pos += PAGE_SIZE * 8;
cur_bmp_pos = 0;
goto get_next_bmp_page;
}
/* If we have reached the end of the bitmap, we are done. */
if (unlikely(((bmp_pos + cur_bmp_pos) >> 3) >= i_size))
goto unm_EOD;
ia_pos = (bmp_pos + cur_bmp_pos) <<
ndir->itype.index.block_size_bits;
}
ntfs_debug("Handling index buffer 0x%llx.",
(unsigned long long)bmp_pos + cur_bmp_pos);
/* If the current index buffer is in the same page we reuse the page. */
if ((prev_ia_pos & (s64)PAGE_MASK) !=
(ia_pos & (s64)PAGE_MASK)) {
prev_ia_pos = ia_pos;
if (likely(ia_page != NULL)) {
unlock_page(ia_page);
ntfs_unmap_page(ia_page);
}
/*
* Map the page cache page containing the current ia_pos,
* reading it from disk if necessary.
*/
ia_page = ntfs_map_page(ia_mapping, ia_pos >> PAGE_SHIFT);
if (IS_ERR(ia_page)) {
ntfs_error(sb, "Reading index allocation data failed.");
err = PTR_ERR(ia_page);
ia_page = NULL;
goto err_out;
}
lock_page(ia_page);
kaddr = (u8*)page_address(ia_page);
}
/* Get the current index buffer. */
ia = (INDEX_ALLOCATION*)(kaddr + (ia_pos & ~PAGE_MASK &
~(s64)(ndir->itype.index.block_size - 1)));
/* Bounds checks. */
if (unlikely((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE)) {
ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
"inode 0x%lx or driver bug.", vdir->i_ino);
goto err_out;
}
/* Catch multi sector transfer fixup errors. */
if (unlikely(!ntfs_is_indx_record(ia->magic))) {
ntfs_error(sb, "Directory index record with vcn 0x%llx is "
"corrupt. Corrupt inode 0x%lx. Run chkdsk.",
(unsigned long long)ia_pos >>
ndir->itype.index.vcn_size_bits, vdir->i_ino);
goto err_out;
}
if (unlikely(sle64_to_cpu(ia->index_block_vcn) != (ia_pos &
~(s64)(ndir->itype.index.block_size - 1)) >>
ndir->itype.index.vcn_size_bits)) {
ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is "
"different from expected VCN (0x%llx). "
"Directory inode 0x%lx is corrupt or driver "
"bug. ", (unsigned long long)
sle64_to_cpu(ia->index_block_vcn),
(unsigned long long)ia_pos >>
ndir->itype.index.vcn_size_bits, vdir->i_ino);
goto err_out;
}
if (unlikely(le32_to_cpu(ia->index.allocated_size) + 0x18 !=
ndir->itype.index.block_size)) {
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
"0x%lx has a size (%u) differing from the "
"directory specified size (%u). Directory "
"inode is corrupt or driver bug.",
(unsigned long long)ia_pos >>
ndir->itype.index.vcn_size_bits, vdir->i_ino,
le32_to_cpu(ia->index.allocated_size) + 0x18,
ndir->itype.index.block_size);
goto err_out;
}
index_end = (u8*)ia + ndir->itype.index.block_size;
if (unlikely(index_end > kaddr + PAGE_SIZE)) {
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
"0x%lx crosses page boundary. Impossible! "
"Cannot access! This is probably a bug in the "
"driver.", (unsigned long long)ia_pos >>
ndir->itype.index.vcn_size_bits, vdir->i_ino);
goto err_out;
}
ia_start = ia_pos & ~(s64)(ndir->itype.index.block_size - 1);
index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
if (unlikely(index_end > (u8*)ia + ndir->itype.index.block_size)) {
ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory "
"inode 0x%lx exceeds maximum size.",
(unsigned long long)ia_pos >>
ndir->itype.index.vcn_size_bits, vdir->i_ino);
goto err_out;
}
/* The first index entry in this index buffer. */
ie = (INDEX_ENTRY*)((u8*)&ia->index +
le32_to_cpu(ia->index.entries_offset));
/*
* Loop until we exceed valid memory (corruption case) or until we
* reach the last entry or until filldir tells us it has had enough
* or signals an error (both covered by the rc test).
*/
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
ntfs_debug("In index allocation, offset 0x%llx.",
(unsigned long long)ia_start +
(unsigned long long)((u8*)ie - (u8*)ia));
/* Bounds checks. */
if (unlikely((u8*)ie < (u8*)ia || (u8*)ie +
sizeof(INDEX_ENTRY_HEADER) > index_end ||
(u8*)ie + le16_to_cpu(ie->key_length) >
index_end))
goto err_out;
/* The last entry cannot contain a name. */
if (ie->flags & INDEX_ENTRY_END)
break;
/* Skip index block entry if continuing previous readdir. */
if (ia_pos - ia_start > (u8*)ie - (u8*)ia)
continue;
/* Advance the position even if going to skip the entry. */
actor->pos = (u8*)ie - (u8*)ia +
(sle64_to_cpu(ia->index_block_vcn) <<
ndir->itype.index.vcn_size_bits) +
vol->mft_record_size;
/*
* Submit the name to the @filldir callback. Note,
* ntfs_filldir() drops the lock on @ia_page but it retakes it
* before returning, unless a non-zero value is returned in
* which case the page is left unlocked.
*/
rc = ntfs_filldir(vol, ndir, ia_page, ie, name, actor);
if (rc) {
/* @ia_page is already unlocked in this case. */
ntfs_unmap_page(ia_page);
ntfs_unmap_page(bmp_page);
iput(bmp_vi);
goto abort;
}
}
goto find_next_index_buffer;
unm_EOD:
if (ia_page) {
unlock_page(ia_page);
ntfs_unmap_page(ia_page);
}
ntfs_unmap_page(bmp_page);
iput(bmp_vi);
EOD:
/* We are finished, set fpos to EOD. */
actor->pos = i_size + vol->mft_record_size;
abort:
kfree(name);
return 0;
err_out:
if (bmp_page) {
ntfs_unmap_page(bmp_page);
iput_err_out:
iput(bmp_vi);
}
if (ia_page) {
unlock_page(ia_page);
ntfs_unmap_page(ia_page);
}
kfree(ir);
kfree(name);
if (ctx)
ntfs_attr_put_search_ctx(ctx);
if (m)
unmap_mft_record(ndir);
if (!err)
err = -EIO;
ntfs_debug("Failed. Returning error code %i.", -err);
return err;
}
/**
* ntfs_dir_open - called when an inode is about to be opened
* @vi: inode to be opened
* @filp: file structure describing the inode
*
* Limit directory size to the page cache limit on architectures where unsigned
* long is 32-bits. This is the most we can do for now without overflowing the
* page cache page index. Doing it this way means we don't run into problems
* because of existing too large directories. It would be better to allow the
* user to read the accessible part of the directory but I doubt very much
* anyone is going to hit this check on a 32-bit architecture, so there is no
* point in adding the extra complexity required to support this.
*
* On 64-bit architectures, the check is hopefully optimized away by the
* compiler.
*/
static int ntfs_dir_open(struct inode *vi, struct file *filp)
{
if (sizeof(unsigned long) < 8) {
if (i_size_read(vi) > MAX_LFS_FILESIZE)
return -EFBIG;
}
return 0;
}
#ifdef NTFS_RW
/**
* ntfs_dir_fsync - sync a directory to disk
* @filp: directory to be synced
* @dentry: dentry describing the directory to sync
* @datasync: if non-zero only flush user data and not metadata
*
* Data integrity sync of a directory to disk. Used for fsync, fdatasync, and
* msync system calls. This function is based on file.c::ntfs_file_fsync().
*
* Write the mft record and all associated extent mft records as well as the
* $INDEX_ALLOCATION and $BITMAP attributes and then sync the block device.
*
* If @datasync is true, we do not wait on the inode(s) to be written out
* but we always wait on the page cache pages to be written out.
*
* Note: In the past @filp could be NULL so we ignore it as we don't need it
* anyway.
*
* Locking: Caller must hold i_mutex on the inode.
*
* TODO: We should probably also write all attribute/index inodes associated
* with this inode but since we have no simple way of getting to them we ignore
* this problem for now. We do write the $BITMAP attribute if it is present
* which is the important one for a directory so things are not too bad.
*/
static int ntfs_dir_fsync(struct file *filp, loff_t start, loff_t end,
int datasync)
{
struct inode *bmp_vi, *vi = filp->f_mapping->host;
int err, ret;
ntfs_attr na;
ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
err = file_write_and_wait_range(filp, start, end);
if (err)
return err;
inode_lock(vi);
BUG_ON(!S_ISDIR(vi->i_mode));
/* If the bitmap attribute inode is in memory sync it, too. */
na.mft_no = vi->i_ino;
na.type = AT_BITMAP;
na.name = I30;
na.name_len = 4;
bmp_vi = ilookup5(vi->i_sb, vi->i_ino, ntfs_test_inode, &na);
if (bmp_vi) {
write_inode_now(bmp_vi, !datasync);
iput(bmp_vi);
}
ret = __ntfs_write_inode(vi, 1);
write_inode_now(vi, !datasync);
err = sync_blockdev(vi->i_sb->s_bdev);
if (unlikely(err && !ret))
ret = err;
if (likely(!ret))
ntfs_debug("Done.");
else
ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
"%u.", datasync ? "data" : "", vi->i_ino, -ret);
inode_unlock(vi);
return ret;
}
#endif /* NTFS_RW */
const struct file_operations ntfs_dir_ops = {
.llseek = generic_file_llseek, /* Seek inside directory. */
.read = generic_read_dir, /* Return -EISDIR. */
.iterate = ntfs_readdir, /* Read directory contents. */
#ifdef NTFS_RW
.fsync = ntfs_dir_fsync, /* Sync a directory to disk. */
#endif /* NTFS_RW */
/*.ioctl = ,*/ /* Perform function on the
mounted filesystem. */
.open = ntfs_dir_open, /* Open directory. */
};