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linux/fs/ntfs/dir.c
Arjan van de Ven 4b6f5d20b0 [PATCH] Make most file operations structs in fs/ const 
This is a conversion to make the various file_operations structs in fs/
const.  Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:06 -08:00

1569 lines
52 KiB
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/**
* dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project.
*
* Copyright (c) 2001-2005 Anton Altaparmakov
* Copyright (c) 2002 Richard Russon
*
* 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 <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include "dir.h"
#include "aops.h"
#include "attrib.h"
#include "mft.h"
#include "debug.h"
#include "ntfs.h"
/**
* The little endian Unicode string $I30 as a global constant.
*/
ntfschar I30[5] = { const_cpu_to_le16('$'), const_cpu_to_le16('I'),
const_cpu_to_le16('3'), const_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_CACHE_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_CACHE_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_CACHE_MASK));
/* Bounds checks. */
if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_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_CACHE_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_CACHE_SHIFT == vcn <<
vol->cluster_size_bits >>
PAGE_CACHE_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_CACHE_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_CACHE_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_CACHE_MASK));
/* Bounds checks. */
if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_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_CACHE_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_CACHE_SHIFT == vcn <<
vol->cluster_size_bits >>
PAGE_CACHE_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
* @fpos: position in the directory
* @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
* @dirent: vfs filldir callback context
* @filldir: vfs filldir callback
*
* 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, loff_t fpos,
ntfs_inode *ndir, struct page *ia_page, INDEX_ENTRY *ie,
u8 *name, void *dirent, filldir_t filldir)
{
unsigned long mref;
int name_len, rc;
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, fpos, mref,
dt_type == DT_DIR ? "DIR" : "REG");
rc = filldir(dirent, name, name_len, fpos, mref, dt_type);
/* Relock the page but not if we are aborting ->readdir. */
if (!rc && ia_page)
lock_page(ia_page);
return rc;
}
/*
* 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 *filp, void *dirent, filldir_t filldir)
{
s64 ia_pos, ia_start, prev_ia_pos, bmp_pos;
loff_t fpos, i_size;
struct inode *bmp_vi, *vdir = filp->f_dentry->d_inode;
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;
fpos = filp->f_pos;
ntfs_debug("Entering for inode 0x%lx, fpos 0x%llx.",
vdir->i_ino, fpos);
rc = err = 0;
/* Are we at end of dir yet? */
i_size = i_size_read(vdir);
if (fpos >= i_size + vol->mft_record_size)
goto done;
/* Emulate . and .. for all directories. */
if (!fpos) {
ntfs_debug("Calling filldir for . with len 1, fpos 0x0, "
"inode 0x%lx, DT_DIR.", vdir->i_ino);
rc = filldir(dirent, ".", 1, fpos, vdir->i_ino, DT_DIR);
if (rc)
goto done;
fpos++;
}
if (fpos == 1) {
ntfs_debug("Calling filldir for .. with len 2, fpos 0x1, "
"inode 0x%lx, DT_DIR.",
(unsigned long)parent_ino(filp->f_dentry));
rc = filldir(dirent, "..", 2, fpos,
parent_ino(filp->f_dentry), DT_DIR);
if (rc)
goto done;
fpos++;
}
m = NULL;
ctx = NULL;
/*
* Allocate a buffer to store the current name being processed
* converted to format determined by current NLS.
*/
name = (u8*)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 (fpos >= 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)fpos;
/* 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 = (INDEX_ROOT*)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. */
fpos = (u8*)ie - (u8*)ir;
/* Submit the name to the filldir callback. */
rc = ntfs_filldir(vol, fpos, ndir, NULL, ie, name, dirent,
filldir);
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. */
fpos = vol->mft_record_size;
skip_index_root:
kaddr = NULL;
prev_ia_pos = -1LL;
/* Get the offset into the index allocation attribute. */
ia_pos = (s64)fpos - vol->mft_record_size;
ia_mapping = vdir->i_mapping;
bmp_vi = ndir->itype.index.bmp_ino;
if (unlikely(!bmp_vi)) {
ntfs_debug("Inode 0x%lx, regetting 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;
}
ndir->itype.index.bmp_ino = bmp_vi;
}
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 err_out;
}
/* Get the starting bit position in the current bitmap page. */
cur_bmp_pos = bmp_pos & ((PAGE_CACHE_SIZE * 8) - 1);
bmp_pos &= ~(u64)((PAGE_CACHE_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_CACHE_SHIFT),
(unsigned long long)bmp_pos &
(unsigned long long)((PAGE_CACHE_SIZE * 8) - 1));
bmp_page = ntfs_map_page(bmp_mapping,
bmp_pos >> (3 + PAGE_CACHE_SHIFT));
if (IS_ERR(bmp_page)) {
ntfs_error(sb, "Reading index bitmap failed.");
err = PTR_ERR(bmp_page);
bmp_page = NULL;
goto 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_CACHE_SIZE)) {
ntfs_unmap_page(bmp_page);
bmp_pos += PAGE_CACHE_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_CACHE_MASK) !=
(ia_pos & (s64)PAGE_CACHE_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_CACHE_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_CACHE_MASK &
~(s64)(ndir->itype.index.block_size - 1)));
/* Bounds checks. */
if (unlikely((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_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_CACHE_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. */
fpos = (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, fpos, ndir, ia_page, ie, name, dirent,
filldir);
if (rc) {
/* @ia_page is already unlocked in this case. */
ntfs_unmap_page(ia_page);
ntfs_unmap_page(bmp_page);
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);
EOD:
/* We are finished, set fpos to EOD. */
fpos = i_size + vol->mft_record_size;
abort:
kfree(name);
done:
#ifdef DEBUG
if (!rc)
ntfs_debug("EOD, fpos 0x%llx, returning 0.", fpos);
else
ntfs_debug("filldir returned %i, fpos 0x%llx, returning 0.",
rc, fpos);
#endif
filp->f_pos = fpos;
return 0;
err_out:
if (bmp_page)
ntfs_unmap_page(bmp_page);
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);
filp->f_pos = fpos;
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, struct dentry *dentry,
int datasync)
{
struct inode *vi = dentry->d_inode;
ntfs_inode *ni = NTFS_I(vi);
int err, ret;
ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
BUG_ON(!S_ISDIR(vi->i_mode));
if (NInoIndexAllocPresent(ni) && ni->itype.index.bmp_ino)
write_inode_now(ni->itype.index.bmp_ino, !datasync);
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);
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. */
.readdir = ntfs_readdir, /* Read directory contents. */
#ifdef NTFS_RW
.fsync = ntfs_dir_fsync, /* Sync a directory to disk. */
/*.aio_fsync = ,*/ /* Sync all outstanding async
i/o operations on a kiocb. */
#endif /* NTFS_RW */
/*.ioctl = ,*/ /* Perform function on the
mounted filesystem. */
.open = ntfs_dir_open, /* Open directory. */
};
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