diff options
Diffstat (limited to 'fs/ntfs/dir.c')
| -rw-r--r-- | fs/ntfs/dir.c | 1569 |
1 files changed, 1569 insertions, 0 deletions
diff --git a/fs/ntfs/dir.c b/fs/ntfs/dir.c new file mode 100644 index 00000000000..93577561cdb --- /dev/null +++ b/fs/ntfs/dir.c @@ -0,0 +1,1569 @@ +/** + * dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project. + * + * Copyright (c) 2001-2004 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_sem 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 { + if (name) + 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 { + if (name) + 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 file system. + +/** + * 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; + |