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Diffstat (limited to '')
| -rw-r--r-- | fs/ntfs/dir.c | 1538 |
1 files changed, 1538 insertions, 0 deletions
diff --git a/fs/ntfs/dir.c b/fs/ntfs/dir.c new file mode 100644 index 000000000..cd96083a1 --- /dev/null +++ b/fs/ntfs/dir.c @@ -0,0 +1,1538 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/** + * dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project. + * + * Copyright (c) 2001-2007 Anton Altaparmakov + * Copyright (c) 2002 Richard Russon + */ + +#include <linux/buffer_head.h> +#include <linux/slab.h> +#include <linux/blkdev.h> + +#include "dir.h" +#include "aops.h" +#include "attrib.h" +#include "mft.h" +#include "debug.h" +#include "ntfs.h" + +/** + * The little endian Unicode string $I30 as a global constant. + */ +ntfschar I30[5] = { cpu_to_le16('$'), cpu_to_le16('I'), + cpu_to_le16('3'), cpu_to_le16('0'), 0 }; + +/** + * ntfs_lookup_inode_by_name - find an inode in a directory given its name + * @dir_ni: ntfs inode of the directory in which to search for the name + * @uname: Unicode name for which to search in the directory + * @uname_len: length of the name @uname in Unicode characters + * @res: return the found file name if necessary (see below) + * + * Look for an inode with name @uname in the directory with inode @dir_ni. + * ntfs_lookup_inode_by_name() walks the contents of the directory looking for + * the Unicode name. If the name is found in the directory, the corresponding + * inode number (>= 0) is returned as a mft reference in cpu format, i.e. it + * is a 64-bit number containing the sequence number. + * + * On error, a negative value is returned corresponding to the error code. In + * particular if the inode is not found -ENOENT is returned. Note that you + * can't just check the return value for being negative, you have to check the + * inode number for being negative which you can extract using MREC(return + * value). + * + * Note, @uname_len does not include the (optional) terminating NULL character. + * + * Note, we look for a case sensitive match first but we also look for a case + * insensitive match at the same time. If we find a case insensitive match, we + * save that for the case that we don't find an exact match, where we return + * the case insensitive match and setup @res (which we allocate!) with the mft + * reference, the file name type, length and with a copy of the little endian + * Unicode file name itself. If we match a file name which is in the DOS name + * space, we only return the mft reference and file name type in @res. + * ntfs_lookup() then uses this to find the long file name in the inode itself. + * This is to avoid polluting the dcache with short file names. We want them to + * work but we don't care for how quickly one can access them. This also fixes + * the dcache aliasing issues. + * + * Locking: - Caller must hold i_mutex on the directory. + * - Each page cache page in the index allocation mapping must be + * locked whilst being accessed otherwise we may find a corrupt + * page due to it being under ->writepage at the moment which + * applies the mst protection fixups before writing out and then + * removes them again after the write is complete after which it + * unlocks the page. + */ +MFT_REF ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname, + const int uname_len, ntfs_name **res) +{ + ntfs_volume *vol = dir_ni->vol; + struct super_block *sb = vol->sb; + MFT_RECORD *m; + INDEX_ROOT *ir; + INDEX_ENTRY *ie; + INDEX_ALLOCATION *ia; + u8 *index_end; + u64 mref; + ntfs_attr_search_ctx *ctx; + int err, rc; + VCN vcn, old_vcn; + struct address_space *ia_mapping; + struct page *page; + u8 *kaddr; + ntfs_name *name = NULL; + + BUG_ON(!S_ISDIR(VFS_I(dir_ni)->i_mode)); + BUG_ON(NInoAttr(dir_ni)); + /* Get hold of the mft record for the directory. */ + m = map_mft_record(dir_ni); + if (IS_ERR(m)) { + ntfs_error(sb, "map_mft_record() failed with error code %ld.", + -PTR_ERR(m)); + return ERR_MREF(PTR_ERR(m)); + } + ctx = ntfs_attr_get_search_ctx(dir_ni, m); + if (unlikely(!ctx)) { + err = -ENOMEM; + goto err_out; + } + /* Find the index root attribute in the mft record. */ + err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL, + 0, ctx); + if (unlikely(err)) { + if (err == -ENOENT) { + ntfs_error(sb, "Index root attribute missing in " + "directory inode 0x%lx.", + dir_ni->mft_no); + err = -EIO; + } + goto err_out; + } + /* Get to the index root value (it's been verified in read_inode). */ + ir = (INDEX_ROOT*)((u8*)ctx->attr + + le16_to_cpu(ctx->attr->data.resident.value_offset)); + index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length); + /* The first index entry. */ + ie = (INDEX_ENTRY*)((u8*)&ir->index + + le32_to_cpu(ir->index.entries_offset)); + /* + * Loop until we exceed valid memory (corruption case) or until we + * reach the last entry. + */ + for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { + /* Bounds checks. */ + if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie + + sizeof(INDEX_ENTRY_HEADER) > index_end || + (u8*)ie + le16_to_cpu(ie->key_length) > + index_end) + goto dir_err_out; + /* + * The last entry cannot contain a name. It can however contain + * a pointer to a child node in the B+tree so we just break out. + */ + if (ie->flags & INDEX_ENTRY_END) + break; + /* + * We perform a case sensitive comparison and if that matches + * we are done and return the mft reference of the inode (i.e. + * the inode number together with the sequence number for + * consistency checking). We convert it to cpu format before + * returning. + */ + if (ntfs_are_names_equal(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, + CASE_SENSITIVE, vol->upcase, vol->upcase_len)) { +found_it: + /* + * We have a perfect match, so we don't need to care + * about having matched imperfectly before, so we can + * free name and set *res to NULL. + * However, if the perfect match is a short file name, + * we need to signal this through *res, so that + * ntfs_lookup() can fix dcache aliasing issues. + * As an optimization we just reuse an existing + * allocation of *res. + */ + if (ie->key.file_name.file_name_type == FILE_NAME_DOS) { + if (!name) { + name = kmalloc(sizeof(ntfs_name), + GFP_NOFS); + if (!name) { + err = -ENOMEM; + goto err_out; + } + } + name->mref = le64_to_cpu( + ie->data.dir.indexed_file); + name->type = FILE_NAME_DOS; + name->len = 0; + *res = name; + } else { + kfree(name); + *res = NULL; + } + mref = le64_to_cpu(ie->data.dir.indexed_file); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(dir_ni); + return mref; + } + /* + * For a case insensitive mount, we also perform a case + * insensitive comparison (provided the file name is not in the + * POSIX namespace). If the comparison matches, and the name is + * in the WIN32 namespace, we cache the filename in *res so + * that the caller, ntfs_lookup(), can work on it. If the + * comparison matches, and the name is in the DOS namespace, we + * only cache the mft reference and the file name type (we set + * the name length to zero for simplicity). + */ + if (!NVolCaseSensitive(vol) && + ie->key.file_name.file_name_type && + ntfs_are_names_equal(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, + IGNORE_CASE, vol->upcase, vol->upcase_len)) { + int name_size = sizeof(ntfs_name); + u8 type = ie->key.file_name.file_name_type; + u8 len = ie->key.file_name.file_name_length; + + /* Only one case insensitive matching name allowed. */ + if (name) { + ntfs_error(sb, "Found already allocated name " + "in phase 1. Please run chkdsk " + "and if that doesn't find any " + "errors please report you saw " + "this message to " + "linux-ntfs-dev@lists." + "sourceforge.net."); + goto dir_err_out; + } + + if (type != FILE_NAME_DOS) + name_size += len * sizeof(ntfschar); + name = kmalloc(name_size, GFP_NOFS); + if (!name) { + err = -ENOMEM; + goto err_out; + } + name->mref = le64_to_cpu(ie->data.dir.indexed_file); + name->type = type; + if (type != FILE_NAME_DOS) { + name->len = len; + memcpy(name->name, ie->key.file_name.file_name, + len * sizeof(ntfschar)); + } else + name->len = 0; + *res = name; + } + /* + * Not a perfect match, need to do full blown collation so we + * know which way in the B+tree we have to go. + */ + rc = ntfs_collate_names(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, 1, + IGNORE_CASE, vol->upcase, vol->upcase_len); + /* + * If uname collates before the name of the current entry, there + * is definitely no such name in this index but we might need to + * descend into the B+tree so we just break out of the loop. + */ + if (rc == -1) + break; + /* The names are not equal, continue the search. */ + if (rc) + continue; + /* + * Names match with case insensitive comparison, now try the + * case sensitive comparison, which is required for proper + * collation. + */ + rc = ntfs_collate_names(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, 1, + CASE_SENSITIVE, vol->upcase, vol->upcase_len); + if (rc == -1) + break; + if (rc) + continue; + /* + * Perfect match, this will never happen as the + * ntfs_are_names_equal() call will have gotten a match but we + * still treat it correctly. + */ + goto found_it; + } + /* + * We have finished with this index without success. Check for the + * presence of a child node and if not present return -ENOENT, unless + * we have got a matching name cached in name in which case return the + * mft reference associated with it. + */ + if (!(ie->flags & INDEX_ENTRY_NODE)) { + if (name) { + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(dir_ni); + return name->mref; + } + ntfs_debug("Entry not found."); + err = -ENOENT; + goto err_out; + } /* Child node present, descend into it. */ + /* Consistency check: Verify that an index allocation exists. */ + if (!NInoIndexAllocPresent(dir_ni)) { + ntfs_error(sb, "No index allocation attribute but index entry " + "requires one. Directory inode 0x%lx is " + "corrupt or driver bug.", dir_ni->mft_no); + goto err_out; + } + /* Get the starting vcn of the index_block holding the child node. */ + vcn = sle64_to_cpup((sle64*)((u8*)ie + le16_to_cpu(ie->length) - 8)); + ia_mapping = VFS_I(dir_ni)->i_mapping; + /* + * We are done with the index root and the mft record. Release them, + * otherwise we deadlock with ntfs_map_page(). + */ + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(dir_ni); + m = NULL; + ctx = NULL; +descend_into_child_node: + /* + * Convert vcn to index into the index allocation attribute in units + * of PAGE_SIZE and map the page cache page, reading it from + * disk if necessary. + */ + page = ntfs_map_page(ia_mapping, vcn << + dir_ni->itype.index.vcn_size_bits >> PAGE_SHIFT); + if (IS_ERR(page)) { + ntfs_error(sb, "Failed to map directory index page, error %ld.", + -PTR_ERR(page)); + err = PTR_ERR(page); + goto err_out; + } + lock_page(page); + kaddr = (u8*)page_address(page); +fast_descend_into_child_node: + /* Get to the index allocation block. */ + ia = (INDEX_ALLOCATION*)(kaddr + ((vcn << + dir_ni->itype.index.vcn_size_bits) & ~PAGE_MASK)); + /* Bounds checks. */ + if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE) { + ntfs_error(sb, "Out of bounds check failed. Corrupt directory " + "inode 0x%lx or driver bug.", dir_ni->mft_no); + goto unm_err_out; + } + /* Catch multi sector transfer fixup errors. */ + if (unlikely(!ntfs_is_indx_record(ia->magic))) { + ntfs_error(sb, "Directory index record with vcn 0x%llx is " + "corrupt. Corrupt inode 0x%lx. Run chkdsk.", + (unsigned long long)vcn, dir_ni->mft_no); + goto unm_err_out; + } + if (sle64_to_cpu(ia->index_block_vcn) != vcn) { + ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is " + "different from expected VCN (0x%llx). " + "Directory inode 0x%lx is corrupt or driver " + "bug.", (unsigned long long) + sle64_to_cpu(ia->index_block_vcn), + (unsigned long long)vcn, dir_ni->mft_no); + goto unm_err_out; + } + if (le32_to_cpu(ia->index.allocated_size) + 0x18 != + dir_ni->itype.index.block_size) { + ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " + "0x%lx has a size (%u) differing from the " + "directory specified size (%u). Directory " + "inode is corrupt or driver bug.", + (unsigned long long)vcn, dir_ni->mft_no, + le32_to_cpu(ia->index.allocated_size) + 0x18, + dir_ni->itype.index.block_size); + goto unm_err_out; + } + index_end = (u8*)ia + dir_ni->itype.index.block_size; + if (index_end > kaddr + PAGE_SIZE) { + ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " + "0x%lx crosses page boundary. Impossible! " + "Cannot access! This is probably a bug in the " + "driver.", (unsigned long long)vcn, + dir_ni->mft_no); + goto unm_err_out; + } + index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length); + if (index_end > (u8*)ia + dir_ni->itype.index.block_size) { + ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory " + "inode 0x%lx exceeds maximum size.", + (unsigned long long)vcn, dir_ni->mft_no); + goto unm_err_out; + } + /* The first index entry. */ + ie = (INDEX_ENTRY*)((u8*)&ia->index + + le32_to_cpu(ia->index.entries_offset)); + /* + * Iterate similar to above big loop but applied to index buffer, thus + * loop until we exceed valid memory (corruption case) or until we + * reach the last entry. + */ + for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { + /* Bounds check. */ + if ((u8*)ie < (u8*)ia || (u8*)ie + + sizeof(INDEX_ENTRY_HEADER) > index_end || + (u8*)ie + le16_to_cpu(ie->key_length) > + index_end) { + ntfs_error(sb, "Index entry out of bounds in " + "directory inode 0x%lx.", + dir_ni->mft_no); + goto unm_err_out; + } + /* + * The last entry cannot contain a name. It can however contain + * a pointer to a child node in the B+tree so we just break out. + */ + if (ie->flags & INDEX_ENTRY_END) + break; + /* + * We perform a case sensitive comparison and if that matches + * we are done and return the mft reference of the inode (i.e. + * the inode number together with the sequence number for + * consistency checking). We convert it to cpu format before + * returning. + */ + if (ntfs_are_names_equal(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, + CASE_SENSITIVE, vol->upcase, vol->upcase_len)) { +found_it2: + /* + * We have a perfect match, so we don't need to care + * about having matched imperfectly before, so we can + * free name and set *res to NULL. + * However, if the perfect match is a short file name, + * we need to signal this through *res, so that + * ntfs_lookup() can fix dcache aliasing issues. + * As an optimization we just reuse an existing + * allocation of *res. + */ + if (ie->key.file_name.file_name_type == FILE_NAME_DOS) { + if (!name) { + name = kmalloc(sizeof(ntfs_name), + GFP_NOFS); + if (!name) { + err = -ENOMEM; + goto unm_err_out; + } + } + name->mref = le64_to_cpu( + ie->data.dir.indexed_file); + name->type = FILE_NAME_DOS; + name->len = 0; + *res = name; + } else { + kfree(name); + *res = NULL; + } + mref = le64_to_cpu(ie->data.dir.indexed_file); + unlock_page(page); + ntfs_unmap_page(page); + return mref; + } + /* + * For a case insensitive mount, we also perform a case + * insensitive comparison (provided the file name is not in the + * POSIX namespace). If the comparison matches, and the name is + * in the WIN32 namespace, we cache the filename in *res so + * that the caller, ntfs_lookup(), can work on it. If the + * comparison matches, and the name is in the DOS namespace, we + * only cache the mft reference and the file name type (we set + * the name length to zero for simplicity). + */ + if (!NVolCaseSensitive(vol) && + ie->key.file_name.file_name_type && + ntfs_are_names_equal(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, + IGNORE_CASE, vol->upcase, vol->upcase_len)) { + int name_size = sizeof(ntfs_name); + u8 type = ie->key.file_name.file_name_type; + u8 len = ie->key.file_name.file_name_length; + + /* Only one case insensitive matching name allowed. */ + if (name) { + ntfs_error(sb, "Found already allocated name " + "in phase 2. Please run chkdsk " + "and if that doesn't find any " + "errors please report you saw " + "this message to " + "linux-ntfs-dev@lists." + "sourceforge.net."); + unlock_page(page); + ntfs_unmap_page(page); + goto dir_err_out; + } + + if (type != FILE_NAME_DOS) + name_size += len * sizeof(ntfschar); + name = kmalloc(name_size, GFP_NOFS); + if (!name) { + err = -ENOMEM; + goto unm_err_out; + } + name->mref = le64_to_cpu(ie->data.dir.indexed_file); + name->type = type; + if (type != FILE_NAME_DOS) { + name->len = len; + memcpy(name->name, ie->key.file_name.file_name, + len * sizeof(ntfschar)); + } else + name->len = 0; + *res = name; + } + /* + * Not a perfect match, need to do full blown collation so we + * know which way in the B+tree we have to go. + */ + rc = ntfs_collate_names(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, 1, + IGNORE_CASE, vol->upcase, vol->upcase_len); + /* + * If uname collates before the name of the current entry, there + * is definitely no such name in this index but we might need to + * descend into the B+tree so we just break out of the loop. + */ + if (rc == -1) + break; + /* The names are not equal, continue the search. */ + if (rc) + continue; + /* + * Names match with case insensitive comparison, now try the + * case sensitive comparison, which is required for proper + * collation. + */ + rc = ntfs_collate_names(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, 1, + CASE_SENSITIVE, vol->upcase, vol->upcase_len); + if (rc == -1) + break; + if (rc) + continue; + /* + * Perfect match, this will never happen as the + * ntfs_are_names_equal() call will have gotten a match but we + * still treat it correctly. + */ + goto found_it2; + } + /* + * We have finished with this index buffer without success. Check for + * the presence of a child node. + */ + if (ie->flags & INDEX_ENTRY_NODE) { + if ((ia->index.flags & NODE_MASK) == LEAF_NODE) { + ntfs_error(sb, "Index entry with child node found in " + "a leaf node in directory inode 0x%lx.", + dir_ni->mft_no); + goto unm_err_out; + } + /* Child node present, descend into it. */ + old_vcn = vcn; + vcn = sle64_to_cpup((sle64*)((u8*)ie + + le16_to_cpu(ie->length) - 8)); + if (vcn >= 0) { + /* If vcn is in the same page cache page as old_vcn we + * recycle the mapped page. */ + if (old_vcn << vol->cluster_size_bits >> + PAGE_SHIFT == vcn << + vol->cluster_size_bits >> + PAGE_SHIFT) + goto fast_descend_into_child_node; + unlock_page(page); + ntfs_unmap_page(page); + goto descend_into_child_node; + } + ntfs_error(sb, "Negative child node vcn in directory inode " + "0x%lx.", dir_ni->mft_no); + goto unm_err_out; + } + /* + * No child node present, return -ENOENT, unless we have got a matching + * name cached in name in which case return the mft reference + * associated with it. + */ + if (name) { + unlock_page(page); + ntfs_unmap_page(page); + return name->mref; + } + ntfs_debug("Entry not found."); + err = -ENOENT; +unm_err_out: + unlock_page(page); + ntfs_unmap_page(page); +err_out: + if (!err) + err = -EIO; + if (ctx) + ntfs_attr_put_search_ctx(ctx); + if (m) + unmap_mft_record(dir_ni); + if (name) { + kfree(name); + *res = NULL; + } + return ERR_MREF(err); +dir_err_out: + ntfs_error(sb, "Corrupt directory. Aborting lookup."); + goto err_out; +} + +#if 0 + +// TODO: (AIA) +// The algorithm embedded in this code will be required for the time when we +// want to support adding of entries to directories, where we require correct +// collation of file names in order not to cause corruption of the filesystem. + +/** + * ntfs_lookup_inode_by_name - find an inode in a directory given its name + * @dir_ni: ntfs inode of the directory in which to search for the name + * @uname: Unicode name for which to search in the directory + * @uname_len: length of the name @uname in Unicode characters + * + * Look for an inode with name @uname in the directory with inode @dir_ni. + * ntfs_lookup_inode_by_name() walks the contents of the directory looking for + * the Unicode name. If the name is found in the directory, the corresponding + * inode number (>= 0) is returned as a mft reference in cpu format, i.e. it + * is a 64-bit number containing the sequence number. + * + * On error, a negative value is returned corresponding to the error code. In + * particular if the inode is not found -ENOENT is returned. Note that you + * can't just check the return value for being negative, you have to check the + * inode number for being negative which you can extract using MREC(return + * value). + * + * Note, @uname_len does not include the (optional) terminating NULL character. + */ +u64 ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname, + const int uname_len) +{ + ntfs_volume *vol = dir_ni->vol; + struct super_block *sb = vol->sb; + MFT_RECORD *m; + INDEX_ROOT *ir; + INDEX_ENTRY *ie; + INDEX_ALLOCATION *ia; + u8 *index_end; + u64 mref; + ntfs_attr_search_ctx *ctx; + int err, rc; + IGNORE_CASE_BOOL ic; + VCN vcn, old_vcn; + struct address_space *ia_mapping; + struct page *page; + u8 *kaddr; + + /* Get hold of the mft record for the directory. */ + m = map_mft_record(dir_ni); + if (IS_ERR(m)) { + ntfs_error(sb, "map_mft_record() failed with error code %ld.", + -PTR_ERR(m)); + return ERR_MREF(PTR_ERR(m)); + } + ctx = ntfs_attr_get_search_ctx(dir_ni, m); + if (!ctx) { + err = -ENOMEM; + goto err_out; + } + /* Find the index root attribute in the mft record. */ + err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL, + 0, ctx); + if (unlikely(err)) { + if (err == -ENOENT) { + ntfs_error(sb, "Index root attribute missing in " + "directory inode 0x%lx.", + dir_ni->mft_no); + err = -EIO; + } + goto err_out; + } + /* Get to the index root value (it's been verified in read_inode). */ + ir = (INDEX_ROOT*)((u8*)ctx->attr + + le16_to_cpu(ctx->attr->data.resident.value_offset)); + index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length); + /* The first index entry. */ + ie = (INDEX_ENTRY*)((u8*)&ir->index + + le32_to_cpu(ir->index.entries_offset)); + /* + * Loop until we exceed valid memory (corruption case) or until we + * reach the last entry. + */ + for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { + /* Bounds checks. */ + if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie + + sizeof(INDEX_ENTRY_HEADER) > index_end || + (u8*)ie + le16_to_cpu(ie->key_length) > + index_end) + goto dir_err_out; + /* + * The last entry cannot contain a name. It can however contain + * a pointer to a child node in the B+tree so we just break out. + */ + if (ie->flags & INDEX_ENTRY_END) + break; + /* + * If the current entry has a name type of POSIX, the name is + * case sensitive and not otherwise. This has the effect of us + * not being able to access any POSIX file names which collate + * after the non-POSIX one when they only differ in case, but + * anyone doing screwy stuff like that deserves to burn in + * hell... Doing that kind of stuff on NT4 actually causes + * corruption on the partition even when using SP6a and Linux + * is not involved at all. + */ + ic = ie->key.file_name.file_name_type ? IGNORE_CASE : + CASE_SENSITIVE; + /* + * If the names match perfectly, we are done and return the + * mft reference of the inode (i.e. the inode number together + * with the sequence number for consistency checking. We + * convert it to cpu format before returning. + */ + if (ntfs_are_names_equal(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, ic, + vol->upcase, vol->upcase_len)) { +found_it: + mref = le64_to_cpu(ie->data.dir.indexed_file); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(dir_ni); + return mref; + } + /* + * Not a perfect match, need to do full blown collation so we + * know which way in the B+tree we have to go. + */ + rc = ntfs_collate_names(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, 1, + IGNORE_CASE, vol->upcase, vol->upcase_len); + /* + * If uname collates before the name of the current entry, there + * is definitely no such name in this index but we might need to + * descend into the B+tree so we just break out of the loop. + */ + if (rc == -1) + break; + /* The names are not equal, continue the search. */ + if (rc) + continue; + /* + * Names match with case insensitive comparison, now try the + * case sensitive comparison, which is required for proper + * collation. + */ + rc = ntfs_collate_names(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, 1, + CASE_SENSITIVE, vol->upcase, vol->upcase_len); + if (rc == -1) + break; + if (rc) + continue; + /* + * Perfect match, this will never happen as the + * ntfs_are_names_equal() call will have gotten a match but we + * still treat it correctly. + */ + goto found_it; + } + /* + * We have finished with this index without success. Check for the + * presence of a child node. + */ + if (!(ie->flags & INDEX_ENTRY_NODE)) { + /* No child node, return -ENOENT. */ + err = -ENOENT; + goto err_out; + } /* Child node present, descend into it. */ + /* Consistency check: Verify that an index allocation exists. */ + if (!NInoIndexAllocPresent(dir_ni)) { + ntfs_error(sb, "No index allocation attribute but index entry " + "requires one. Directory inode 0x%lx is " + "corrupt or driver bug.", dir_ni->mft_no); + goto err_out; + } + /* Get the starting vcn of the index_block holding the child node. */ + vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8); + ia_mapping = VFS_I(dir_ni)->i_mapping; + /* + * We are done with the index root and the mft record. Release them, + * otherwise we deadlock with ntfs_map_page(). + */ + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(dir_ni); + m = NULL; + ctx = NULL; +descend_into_child_node: + /* + * Convert vcn to index into the index allocation attribute in units + * of PAGE_SIZE and map the page cache page, reading it from + * disk if necessary. + */ + page = ntfs_map_page(ia_mapping, vcn << + dir_ni->itype.index.vcn_size_bits >> PAGE_SHIFT); + if (IS_ERR(page)) { + ntfs_error(sb, "Failed to map directory index page, error %ld.", + -PTR_ERR(page)); + err = PTR_ERR(page); + goto err_out; + } + lock_page(page); + kaddr = (u8*)page_address(page); +fast_descend_into_child_node: + /* Get to the index allocation block. */ + ia = (INDEX_ALLOCATION*)(kaddr + ((vcn << + dir_ni->itype.index.vcn_size_bits) & ~PAGE_MASK)); + /* Bounds checks. */ + if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE) { + ntfs_error(sb, "Out of bounds check failed. Corrupt directory " + "inode 0x%lx or driver bug.", dir_ni->mft_no); + goto unm_err_out; + } + /* Catch multi sector transfer fixup errors. */ + if (unlikely(!ntfs_is_indx_record(ia->magic))) { + ntfs_error(sb, "Directory index record with vcn 0x%llx is " + "corrupt. Corrupt inode 0x%lx. Run chkdsk.", + (unsigned long long)vcn, dir_ni->mft_no); + goto unm_err_out; + } + if (sle64_to_cpu(ia->index_block_vcn) != vcn) { + ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is " + "different from expected VCN (0x%llx). " + "Directory inode 0x%lx is corrupt or driver " + "bug.", (unsigned long long) + sle64_to_cpu(ia->index_block_vcn), + (unsigned long long)vcn, dir_ni->mft_no); + goto unm_err_out; + } + if (le32_to_cpu(ia->index.allocated_size) + 0x18 != + dir_ni->itype.index.block_size) { + ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " + "0x%lx has a size (%u) differing from the " + "directory specified size (%u). Directory " + "inode is corrupt or driver bug.", + (unsigned long long)vcn, dir_ni->mft_no, + le32_to_cpu(ia->index.allocated_size) + 0x18, + dir_ni->itype.index.block_size); + goto unm_err_out; + } + index_end = (u8*)ia + dir_ni->itype.index.block_size; + if (index_end > kaddr + PAGE_SIZE) { + ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " + "0x%lx crosses page boundary. Impossible! " + "Cannot access! This is probably a bug in the " + "driver.", (unsigned long long)vcn, + dir_ni->mft_no); + goto unm_err_out; + } + index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length); + if (index_end > (u8*)ia + dir_ni->itype.index.block_size) { + ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory " + "inode 0x%lx exceeds maximum size.", + (unsigned long long)vcn, dir_ni->mft_no); + goto unm_err_out; + } + /* The first index entry. */ + ie = (INDEX_ENTRY*)((u8*)&ia->index + + le32_to_cpu(ia->index.entries_offset)); + /* + * Iterate similar to above big loop but applied to index buffer, thus + * loop until we exceed valid memory (corruption case) or until we + * reach the last entry. + */ + for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { + /* Bounds check. */ + if ((u8*)ie < (u8*)ia || (u8*)ie + + sizeof(INDEX_ENTRY_HEADER) > index_end || + (u8*)ie + le16_to_cpu(ie->key_length) > + index_end) { + ntfs_error(sb, "Index entry out of bounds in " + "directory inode 0x%lx.", + dir_ni->mft_no); + goto unm_err_out; + } + /* + * The last entry cannot contain a name. It can however contain + * a pointer to a child node in the B+tree so we just break out. + */ + if (ie->flags & INDEX_ENTRY_END) + break; + /* + * If the current entry has a name type of POSIX, the name is + * case sensitive and not otherwise. This has the effect of us + * not being able to access any POSIX file names which collate + * after the non-POSIX one when they only differ in case, but + * anyone doing screwy stuff like that deserves to burn in + * hell... Doing that kind of stuff on NT4 actually causes + * corruption on the partition even when using SP6a and Linux + * is not involved at all. + */ + ic = ie->key.file_name.file_name_type ? IGNORE_CASE : + CASE_SENSITIVE; + /* + * If the names match perfectly, we are done and return the + * mft reference of the inode (i.e. the inode number together + * with the sequence number for consistency checking. We + * convert it to cpu format before returning. + */ + if (ntfs_are_names_equal(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, ic, + vol->upcase, vol->upcase_len)) { +found_it2: + mref = le64_to_cpu(ie->data.dir.indexed_file); + unlock_page(page); + ntfs_unmap_page(page); + return mref; + } + /* + * Not a perfect match, need to do full blown collation so we + * know which way in the B+tree we have to go. + */ + rc = ntfs_collate_names(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, 1, + IGNORE_CASE, vol->upcase, vol->upcase_len); + /* + * If uname collates before the name of the current entry, there + * is definitely no such name in this index but we might need to + * descend into the B+tree so we just break out of the loop. + */ + if (rc == -1) + break; + /* The names are not equal, continue the search. */ + if (rc) + continue; + /* + * Names match with case insensitive comparison, now try the + * case sensitive comparison, which is required for proper + * collation. + */ + rc = ntfs_collate_names(uname, uname_len, + (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, 1, + CASE_SENSITIVE, vol->upcase, vol->upcase_len); + if (rc == -1) + break; + if (rc) + continue; + /* + * Perfect match, this will never happen as the + * ntfs_are_names_equal() call will have gotten a match but we + * still treat it correctly. + */ + goto found_it2; + } + /* + * We have finished with this index buffer without success. Check for + * the presence of a child node. + */ + if (ie->flags & INDEX_ENTRY_NODE) { + if ((ia->index.flags & NODE_MASK) == LEAF_NODE) { + ntfs_error(sb, "Index entry with child node found in " + "a leaf node in directory inode 0x%lx.", + dir_ni->mft_no); + goto unm_err_out; + } + /* Child node present, descend into it. */ + old_vcn = vcn; + vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8); + if (vcn >= 0) { + /* If vcn is in the same page cache page as old_vcn we + * recycle the mapped page. */ + if (old_vcn << vol->cluster_size_bits >> + PAGE_SHIFT == vcn << + vol->cluster_size_bits >> + PAGE_SHIFT) + goto fast_descend_into_child_node; + unlock_page(page); + ntfs_unmap_page(page); + goto descend_into_child_node; + } + ntfs_error(sb, "Negative child node vcn in directory inode " + "0x%lx.", dir_ni->mft_no); + goto unm_err_out; + } + /* No child node, return -ENOENT. */ + ntfs_debug("Entry not found."); + err = -ENOENT; +unm_err_out: + unlock_page(page); + ntfs_unmap_page(page); +err_out: + if (!err) + err = -EIO; + if (ctx) + ntfs_attr_put_search_ctx(ctx); + if (m) + unmap_mft_record(dir_ni); + return ERR_MREF(err); +dir_err_out: + ntfs_error(sb, "Corrupt directory. Aborting lookup."); + goto err_out; +} + +#endif + +/** + * ntfs_filldir - ntfs specific filldir method + * @vol: current ntfs volume + * @ndir: ntfs inode of current directory + * @ia_page: page in which the index allocation buffer @ie is in resides + * @ie: current index entry + * @name: buffer to use for the converted name + * @actor: what to feed the entries to + * + * Convert the Unicode @name to the loaded NLS and pass it to the @filldir + * callback. + * + * If @ia_page is not NULL it is the locked page containing the index + * allocation block containing the index entry @ie. + * + * Note, we drop (and then reacquire) the page lock on @ia_page across the + * @filldir() call otherwise we would deadlock with NFSd when it calls ->lookup + * since ntfs_lookup() will lock the same page. As an optimization, we do not + * retake the lock if we are returning a non-zero value as ntfs_readdir() + * would need to drop the lock immediately anyway. + */ +static inline int ntfs_filldir(ntfs_volume *vol, + ntfs_inode *ndir, struct page *ia_page, INDEX_ENTRY *ie, + u8 *name, struct dir_context *actor) +{ + unsigned long mref; + int name_len; + unsigned dt_type; + FILE_NAME_TYPE_FLAGS name_type; + + name_type = ie->key.file_name.file_name_type; + if (name_type == FILE_NAME_DOS) { + ntfs_debug("Skipping DOS name space entry."); + return 0; + } + if (MREF_LE(ie->data.dir.indexed_file) == FILE_root) { + ntfs_debug("Skipping root directory self reference entry."); + return 0; + } + if (MREF_LE(ie->data.dir.indexed_file) < FILE_first_user && + !NVolShowSystemFiles(vol)) { + ntfs_debug("Skipping system file."); + return 0; + } + name_len = ntfs_ucstonls(vol, (ntfschar*)&ie->key.file_name.file_name, + ie->key.file_name.file_name_length, &name, + NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1); + if (name_len <= 0) { + ntfs_warning(vol->sb, "Skipping unrepresentable inode 0x%llx.", + (long long)MREF_LE(ie->data.dir.indexed_file)); + return 0; + } + if (ie->key.file_name.file_attributes & + FILE_ATTR_DUP_FILE_NAME_INDEX_PRESENT) + dt_type = DT_DIR; + else + dt_type = DT_REG; + mref = MREF_LE(ie->data.dir.indexed_file); + /* + * Drop the page lock otherwise we deadlock with NFS when it calls + * ->lookup since ntfs_lookup() will lock the same page. + */ + if (ia_page) + unlock_page(ia_page); + ntfs_debug("Calling filldir for %s with len %i, fpos 0x%llx, inode " + "0x%lx, DT_%s.", name, name_len, actor->pos, mref, + dt_type == DT_DIR ? "DIR" : "REG"); + if (!dir_emit(actor, name, name_len, mref, dt_type)) + return 1; + /* Relock the page but not if we are aborting ->readdir. */ + if (ia_page) + lock_page(ia_page); + return 0; +} + +/* + * We use the same basic approach as the old NTFS driver, i.e. we parse the + * index root entries and then the index allocation entries that are marked + * as in use in the index bitmap. + * + * While this will return the names in random order this doesn't matter for + * ->readdir but OTOH results in a faster ->readdir. + * + * VFS calls ->readdir without BKL but with i_mutex held. This protects the VFS + * parts (e.g. ->f_pos and ->i_size, and it also protects against directory + * modifications). + * + * Locking: - Caller must hold i_mutex on the directory. + * - Each page cache page in the index allocation mapping must be + * locked whilst being accessed otherwise we may find a corrupt + * page due to it being under ->writepage at the moment which + * applies the mst protection fixups before writing out and then + * removes them again after the write is complete after which it + * unlocks the page. + */ +static int ntfs_readdir(struct file *file, struct dir_context *actor) +{ + s64 ia_pos, ia_start, prev_ia_pos, bmp_pos; + loff_t i_size; + struct inode *bmp_vi, *vdir = file_inode(file); + struct super_block *sb = vdir->i_sb; + ntfs_inode *ndir = NTFS_I(vdir); + ntfs_volume *vol = NTFS_SB(sb); + MFT_RECORD *m; + INDEX_ROOT *ir = NULL; + INDEX_ENTRY *ie; + INDEX_ALLOCATION *ia; + u8 *name = NULL; + int rc, err, ir_pos, cur_bmp_pos; + struct address_space *ia_mapping, *bmp_mapping; + struct page *bmp_page = NULL, *ia_page = NULL; + u8 *kaddr, *bmp, *index_end; + ntfs_attr_search_ctx *ctx; + + ntfs_debug("Entering for inode 0x%lx, fpos 0x%llx.", + vdir->i_ino, actor->pos); + rc = err = 0; + /* Are we at end of dir yet? */ + i_size = i_size_read(vdir); + if (actor->pos >= i_size + vol->mft_record_size) + return 0; + /* Emulate . and .. for all directories. */ + if (!dir_emit_dots(file, actor)) + return 0; + m = NULL; + ctx = NULL; + /* + * Allocate a buffer to store the current name being processed + * converted to format determined by current NLS. + */ + name = kmalloc(NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1, GFP_NOFS); + if (unlikely(!name)) { + err = -ENOMEM; + goto err_out; + } + /* Are we jumping straight into the index allocation attribute? */ + if (actor->pos >= vol->mft_record_size) + goto skip_index_root; + /* Get hold of the mft record for the directory. */ + m = map_mft_record(ndir); + if (IS_ERR(m)) { + err = PTR_ERR(m); + m = NULL; + goto err_out; + } + ctx = ntfs_attr_get_search_ctx(ndir, m); + if (unlikely(!ctx)) { + err = -ENOMEM; + goto err_out; + } + /* Get the offset into the index root attribute. */ + ir_pos = (s64)actor->pos; + /* Find the index root attribute in the mft record. */ + err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL, + 0, ctx); + if (unlikely(err)) { + ntfs_error(sb, "Index root attribute missing in directory " + "inode 0x%lx.", vdir->i_ino); + goto err_out; + } + /* + * Copy the index root attribute value to a buffer so that we can put + * the search context and unmap the mft record before calling the + * filldir() callback. We need to do this because of NFSd which calls + * ->lookup() from its filldir callback() and this causes NTFS to + * deadlock as ntfs_lookup() maps the mft record of the directory and + * we have got it mapped here already. The only solution is for us to + * unmap the mft record here so that a call to ntfs_lookup() is able to + * map the mft record without deadlocking. + */ + rc = le32_to_cpu(ctx->attr->data.resident.value_length); + ir = kmalloc(rc, GFP_NOFS); + if (unlikely(!ir)) { + err = -ENOMEM; + goto err_out; + } + /* Copy the index root value (it has been verified in read_inode). */ + memcpy(ir, (u8*)ctx->attr + + le16_to_cpu(ctx->attr->data.resident.value_offset), rc); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(ndir); + ctx = NULL; + m = NULL; + index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length); + /* The first index entry. */ + ie = (INDEX_ENTRY*)((u8*)&ir->index + + le32_to_cpu(ir->index.entries_offset)); + /* + * Loop until we exceed valid memory (corruption case) or until we + * reach the last entry or until filldir tells us it has had enough + * or signals an error (both covered by the rc test). + */ + for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { + ntfs_debug("In index root, offset 0x%zx.", (u8*)ie - (u8*)ir); + /* Bounds checks. */ + if (unlikely((u8*)ie < (u8*)ir || (u8*)ie + + sizeof(INDEX_ENTRY_HEADER) > index_end || + (u8*)ie + le16_to_cpu(ie->key_length) > + index_end)) + goto err_out; + /* The last entry cannot contain a name. */ + if (ie->flags & INDEX_ENTRY_END) + break; + /* Skip index root entry if continuing previous readdir. */ + if (ir_pos > (u8*)ie - (u8*)ir) + continue; + /* Advance the position even if going to skip the entry. */ + actor->pos = (u8*)ie - (u8*)ir; + /* Submit the name to the filldir callback. */ + rc = ntfs_filldir(vol, ndir, NULL, ie, name, actor); + if (rc) { + kfree(ir); + goto abort; + } + } + /* We are done with the index root and can free the buffer. */ + kfree(ir); + ir = NULL; + /* If there is no index allocation attribute we are finished. */ + if (!NInoIndexAllocPresent(ndir)) + goto EOD; + /* Advance fpos to the beginning of the index allocation. */ + actor->pos = vol->mft_record_size; +skip_index_root: + kaddr = NULL; + prev_ia_pos = -1LL; + /* Get the offset into the index allocation attribute. */ + ia_pos = (s64)actor->pos - vol->mft_record_size; + ia_mapping = vdir->i_mapping; + ntfs_debug("Inode 0x%lx, getting index bitmap.", vdir->i_ino); + bmp_vi = ntfs_attr_iget(vdir, AT_BITMAP, I30, 4); + if (IS_ERR(bmp_vi)) { + ntfs_error(sb, "Failed to get bitmap attribute."); + err = PTR_ERR(bmp_vi); + goto err_out; + } + bmp_mapping = bmp_vi->i_mapping; + /* Get the starting bitmap bit position and sanity check it. */ + bmp_pos = ia_pos >> ndir->itype.index.block_size_bits; + if (unlikely(bmp_pos >> 3 >= i_size_read(bmp_vi))) { + ntfs_error(sb, "Current index allocation position exceeds " + "index bitmap size."); + goto iput_err_out; + } + /* Get the starting bit position in the current bitmap page. */ + cur_bmp_pos = bmp_pos & ((PAGE_SIZE * 8) - 1); + bmp_pos &= ~(u64)((PAGE_SIZE * 8) - 1); +get_next_bmp_page: + ntfs_debug("Reading bitmap with page index 0x%llx, bit ofs 0x%llx", + (unsigned long long)bmp_pos >> (3 + PAGE_SHIFT), + (unsigned long long)bmp_pos & + (unsigned long long)((PAGE_SIZE * 8) - 1)); + bmp_page = ntfs_map_page(bmp_mapping, + bmp_pos >> (3 + PAGE_SHIFT)); + if (IS_ERR(bmp_page)) { + ntfs_error(sb, "Reading index bitmap failed."); + err = PTR_ERR(bmp_page); + bmp_page = NULL; + goto iput_err_out; + } + bmp = (u8*)page_address(bmp_page); + /* Find next index block in use. */ + while (!(bmp[cur_bmp_pos >> 3] & (1 << (cur_bmp_pos & 7)))) { +find_next_index_buffer: + cur_bmp_pos++; + /* + * If we have reached the end of the bitmap page, get the next + * page, and put away the old one. + */ + if (unlikely((cur_bmp_pos >> 3) >= PAGE_SIZE)) { + ntfs_unmap_page(bmp_page); + bmp_pos += PAGE_SIZE * 8; + cur_bmp_pos = 0; + goto get_next_bmp_page; + } + /* If we have reached the end of the bitmap, we are done. */ + if (unlikely(((bmp_pos + cur_bmp_pos) >> 3) >= i_size)) + goto unm_EOD; + ia_pos = (bmp_pos + cur_bmp_pos) << + ndir->itype.index.block_size_bits; + } + ntfs_debug("Handling index buffer 0x%llx.", + (unsigned long long)bmp_pos + cur_bmp_pos); + /* If the current index buffer is in the same page we reuse the page. */ + if ((prev_ia_pos & (s64)PAGE_MASK) != + (ia_pos & (s64)PAGE_MASK)) { + prev_ia_pos = ia_pos; + if (likely(ia_page != NULL)) { + unlock_page(ia_page); + ntfs_unmap_page(ia_page); + } + /* + * Map the page cache page containing the current ia_pos, + * reading it from disk if necessary. + */ + ia_page = ntfs_map_page(ia_mapping, ia_pos >> PAGE_SHIFT); + if (IS_ERR(ia_page)) { + ntfs_error(sb, "Reading index allocation data failed."); + err = PTR_ERR(ia_page); + ia_page = NULL; + goto err_out; + } + lock_page(ia_page); + kaddr = (u8*)page_address(ia_page); + } + /* Get the current index buffer. */ + ia = (INDEX_ALLOCATION*)(kaddr + (ia_pos & ~PAGE_MASK & + ~(s64)(ndir->itype.index.block_size - 1))); + /* Bounds checks. */ + if (unlikely((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE)) { + ntfs_error(sb, "Out of bounds check failed. Corrupt directory " + "inode 0x%lx or driver bug.", vdir->i_ino); + goto err_out; + } + /* Catch multi sector transfer fixup errors. */ + if (unlikely(!ntfs_is_indx_record(ia->magic))) { + ntfs_error(sb, "Directory index record with vcn 0x%llx is " + "corrupt. Corrupt inode 0x%lx. Run chkdsk.", + (unsigned long long)ia_pos >> + ndir->itype.index.vcn_size_bits, vdir->i_ino); + goto err_out; + } + if (unlikely(sle64_to_cpu(ia->index_block_vcn) != (ia_pos & + ~(s64)(ndir->itype.index.block_size - 1)) >> + ndir->itype.index.vcn_size_bits)) { + ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is " + "different from expected VCN (0x%llx). " + "Directory inode 0x%lx is corrupt or driver " + "bug. ", (unsigned long long) + sle64_to_cpu(ia->index_block_vcn), + (unsigned long long)ia_pos >> + ndir->itype.index.vcn_size_bits, vdir->i_ino); + goto err_out; + } + if (unlikely(le32_to_cpu(ia->index.allocated_size) + 0x18 != + ndir->itype.index.block_size)) { + ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " + "0x%lx has a size (%u) differing from the " + "directory specified size (%u). Directory " + "inode is corrupt or driver bug.", + (unsigned long long)ia_pos >> + ndir->itype.index.vcn_size_bits, vdir->i_ino, + le32_to_cpu(ia->index.allocated_size) + 0x18, + ndir->itype.index.block_size); + goto err_out; + } + index_end = (u8*)ia + ndir->itype.index.block_size; + if (unlikely(index_end > kaddr + PAGE_SIZE)) { + ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " + "0x%lx crosses page boundary. Impossible! " + "Cannot access! This is probably a bug in the " + "driver.", (unsigned long long)ia_pos >> + ndir->itype.index.vcn_size_bits, vdir->i_ino); + goto err_out; + } + ia_start = ia_pos & ~(s64)(ndir->itype.index.block_size - 1); + index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length); + if (unlikely(index_end > (u8*)ia + ndir->itype.index.block_size)) { + ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory " + "inode 0x%lx exceeds maximum size.", + (unsigned long long)ia_pos >> + ndir->itype.index.vcn_size_bits, vdir->i_ino); + goto err_out; + } + /* The first index entry in this index buffer. */ + ie = (INDEX_ENTRY*)((u8*)&ia->index + + le32_to_cpu(ia->index.entries_offset)); + /* + * Loop until we exceed valid memory (corruption case) or until we + * reach the last entry or until filldir tells us it has had enough + * or signals an error (both covered by the rc test). + */ + for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { + ntfs_debug("In index allocation, offset 0x%llx.", + (unsigned long long)ia_start + + (unsigned long long)((u8*)ie - (u8*)ia)); + /* Bounds checks. */ + if (unlikely((u8*)ie < (u8*)ia || (u8*)ie + + sizeof(INDEX_ENTRY_HEADER) > index_end || + (u8*)ie + le16_to_cpu(ie->key_length) > + index_end)) + goto err_out; + /* The last entry cannot contain a name. */ + if (ie->flags & INDEX_ENTRY_END) + break; + /* Skip index block entry if continuing previous readdir. */ + if (ia_pos - ia_start > (u8*)ie - (u8*)ia) + continue; + /* Advance the position even if going to skip the entry. */ + actor->pos = (u8*)ie - (u8*)ia + + (sle64_to_cpu(ia->index_block_vcn) << + ndir->itype.index.vcn_size_bits) + + vol->mft_record_size; + /* + * Submit the name to the @filldir callback. Note, + * ntfs_filldir() drops the lock on @ia_page but it retakes it + * before returning, unless a non-zero value is returned in + * which case the page is left unlocked. + */ + rc = ntfs_filldir(vol, ndir, ia_page, ie, name, actor); + if (rc) { + /* @ia_page is already unlocked in this case. */ + ntfs_unmap_page(ia_page); + ntfs_unmap_page(bmp_page); + iput(bmp_vi); + goto abort; + } + } + goto find_next_index_buffer; +unm_EOD: + if (ia_page) { + unlock_page(ia_page); + ntfs_unmap_page(ia_page); + } + ntfs_unmap_page(bmp_page); + iput(bmp_vi); +EOD: + /* We are finished, set fpos to EOD. */ + actor->pos = i_size + vol->mft_record_size; +abort: + kfree(name); + return 0; +err_out: + if (bmp_page) { + ntfs_unmap_page(bmp_page); +iput_err_out: + iput(bmp_vi); + } + if (ia_page) { + unlock_page(ia_page); + ntfs_unmap_page(ia_page); + } + kfree(ir); + kfree(name); + if (ctx) + ntfs_attr_put_search_ctx(ctx); + if (m) + unmap_mft_record(ndir); + if (!err) + err = -EIO; + ntfs_debug("Failed. Returning error code %i.", -err); + return err; +} + +/** + * ntfs_dir_open - called when an inode is about to be opened + * @vi: inode to be opened + * @filp: file structure describing the inode + * + * Limit directory size to the page cache limit on architectures where unsigned + * long is 32-bits. This is the most we can do for now without overflowing the + * page cache page index. Doing it this way means we don't run into problems + * because of existing too large directories. It would be better to allow the + * user to read the accessible part of the directory but I doubt very much + * anyone is going to hit this check on a 32-bit architecture, so there is no + * point in adding the extra complexity required to support this. + * + * On 64-bit architectures, the check is hopefully optimized away by the + * compiler. + */ +static int ntfs_dir_open(struct inode *vi, struct file *filp) +{ + if (sizeof(unsigned long) < 8) { + if (i_size_read(vi) > MAX_LFS_FILESIZE) + return -EFBIG; + } + return 0; +} + +#ifdef NTFS_RW + +/** + * ntfs_dir_fsync - sync a directory to disk + * @filp: directory to be synced + * @dentry: dentry describing the directory to sync + * @datasync: if non-zero only flush user data and not metadata + * + * Data integrity sync of a directory to disk. Used for fsync, fdatasync, and + * msync system calls. This function is based on file.c::ntfs_file_fsync(). + * + * Write the mft record and all associated extent mft records as well as the + * $INDEX_ALLOCATION and $BITMAP attributes and then sync the block device. + * + * If @datasync is true, we do not wait on the inode(s) to be written out + * but we always wait on the page cache pages to be written out. + * + * Note: In the past @filp could be NULL so we ignore it as we don't need it + * anyway. + * + * Locking: Caller must hold i_mutex on the inode. + * + * TODO: We should probably also write all attribute/index inodes associated + * with this inode but since we have no simple way of getting to them we ignore + * this problem for now. We do write the $BITMAP attribute if it is present + * which is the important one for a directory so things are not too bad. + */ +static int ntfs_dir_fsync(struct file *filp, loff_t start, loff_t end, + int datasync) +{ + struct inode *bmp_vi, *vi = filp->f_mapping->host; + int err, ret; + ntfs_attr na; + + ntfs_debug("Entering for inode 0x%lx.", vi->i_ino); + + err = file_write_and_wait_range(filp, start, end); + if (err) + return err; + inode_lock(vi); + + BUG_ON(!S_ISDIR(vi->i_mode)); + /* If the bitmap attribute inode is in memory sync it, too. */ + na.mft_no = vi->i_ino; + na.type = AT_BITMAP; + na.name = I30; + na.name_len = 4; + bmp_vi = ilookup5(vi->i_sb, vi->i_ino, ntfs_test_inode, &na); + if (bmp_vi) { + write_inode_now(bmp_vi, !datasync); + iput(bmp_vi); + } + ret = __ntfs_write_inode(vi, 1); + write_inode_now(vi, !datasync); + err = sync_blockdev(vi->i_sb->s_bdev); + if (unlikely(err && !ret)) + ret = err; + if (likely(!ret)) + ntfs_debug("Done."); + else + ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error " + "%u.", datasync ? "data" : "", vi->i_ino, -ret); + inode_unlock(vi); + return ret; +} + +#endif /* NTFS_RW */ + +const struct file_operations ntfs_dir_ops = { + .llseek = generic_file_llseek, /* Seek inside directory. */ + .read = generic_read_dir, /* Return -EISDIR. */ + .iterate = ntfs_readdir, /* Read directory contents. */ +#ifdef NTFS_RW + .fsync = ntfs_dir_fsync, /* Sync a directory to disk. */ +#endif /* NTFS_RW */ + /*.ioctl = ,*/ /* Perform function on the + mounted filesystem. */ + .open = ntfs_dir_open, /* Open directory. */ +}; |