--- /dev/null
+/**
+ * dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project.
+ *
+ * Copyright (c) 2001-2007 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/buffer_head.h>
+#include <linux/slab.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_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
+ * @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_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 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_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. */
+ 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 = filemap_write_and_wait_range(vi->i_mapping, start, end);
+ if (err)
+ return err;
+ mutex_lock(&vi->i_mutex);
+
+ 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, (test_t)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);
+ mutex_unlock(&vi->i_mutex);
+ 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. */
+ /*.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. */
+};
Code Review / kvmfornfv.git / blobdiff