diff options
Diffstat (limited to 'fs/ntfs/namei.c')
-rw-r--r-- | fs/ntfs/namei.c | 392 |
1 files changed, 0 insertions, 392 deletions
diff --git a/fs/ntfs/namei.c b/fs/ntfs/namei.c deleted file mode 100644 index d7498ddc4a..0000000000 --- a/fs/ntfs/namei.c +++ /dev/null @@ -1,392 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * namei.c - NTFS kernel directory inode operations. Part of the Linux-NTFS - * project. - * - * Copyright (c) 2001-2006 Anton Altaparmakov - */ - -#include <linux/dcache.h> -#include <linux/exportfs.h> -#include <linux/security.h> -#include <linux/slab.h> - -#include "attrib.h" -#include "debug.h" -#include "dir.h" -#include "mft.h" -#include "ntfs.h" - -/** - * ntfs_lookup - find the inode represented by a dentry in a directory inode - * @dir_ino: directory inode in which to look for the inode - * @dent: dentry representing the inode to look for - * @flags: lookup flags - * - * In short, ntfs_lookup() looks for the inode represented by the dentry @dent - * in the directory inode @dir_ino and if found attaches the inode to the - * dentry @dent. - * - * In more detail, the dentry @dent specifies which inode to look for by - * supplying the name of the inode in @dent->d_name.name. ntfs_lookup() - * converts the name to Unicode and walks the contents of the directory inode - * @dir_ino looking for the converted Unicode name. If the name is found in the - * directory, the corresponding inode is loaded by calling ntfs_iget() on its - * inode number and the inode is associated with the dentry @dent via a call to - * d_splice_alias(). - * - * If the name is not found in the directory, a NULL inode is inserted into the - * dentry @dent via a call to d_add(). The dentry is then termed a negative - * dentry. - * - * Only if an actual error occurs, do we return an error via ERR_PTR(). - * - * In order to handle the case insensitivity issues of NTFS with regards to the - * dcache and the dcache requiring only one dentry per directory, we deal with - * dentry aliases that only differ in case in ->ntfs_lookup() while maintaining - * a case sensitive dcache. This means that we get the full benefit of dcache - * speed when the file/directory is looked up with the same case as returned by - * ->ntfs_readdir() but that a lookup for any other case (or for the short file - * name) will not find anything in dcache and will enter ->ntfs_lookup() - * instead, where we search the directory for a fully matching file name - * (including case) and if that is not found, we search for a file name that - * matches with different case and if that has non-POSIX semantics we return - * that. We actually do only one search (case sensitive) and keep tabs on - * whether we have found a case insensitive match in the process. - * - * To simplify matters for us, we do not treat the short vs long filenames as - * two hard links but instead if the lookup matches a short filename, we - * return the dentry for the corresponding long filename instead. - * - * There are three cases we need to distinguish here: - * - * 1) @dent perfectly matches (i.e. including case) a directory entry with a - * file name in the WIN32 or POSIX namespaces. In this case - * ntfs_lookup_inode_by_name() will return with name set to NULL and we - * just d_splice_alias() @dent. - * 2) @dent matches (not including case) a directory entry with a file name in - * the WIN32 namespace. In this case ntfs_lookup_inode_by_name() will return - * with name set to point to a kmalloc()ed ntfs_name structure containing - * the properly cased little endian Unicode name. We convert the name to the - * current NLS code page, search if a dentry with this name already exists - * and if so return that instead of @dent. At this point things are - * complicated by the possibility of 'disconnected' dentries due to NFS - * which we deal with appropriately (see the code comments). The VFS will - * then destroy the old @dent and use the one we returned. If a dentry is - * not found, we allocate a new one, d_splice_alias() it, and return it as - * above. - * 3) @dent matches either perfectly or not (i.e. we don't care about case) a - * directory entry with a file name in the DOS namespace. In this case - * ntfs_lookup_inode_by_name() will return with name set to point to a - * kmalloc()ed ntfs_name structure containing the mft reference (cpu endian) - * of the inode. We use the mft reference to read the inode and to find the - * file name in the WIN32 namespace corresponding to the matched short file - * name. We then convert the name to the current NLS code page, and proceed - * searching for a dentry with this name, etc, as in case 2), above. - * - * Locking: Caller must hold i_mutex on the directory. - */ -static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, - unsigned int flags) -{ - ntfs_volume *vol = NTFS_SB(dir_ino->i_sb); - struct inode *dent_inode; - ntfschar *uname; - ntfs_name *name = NULL; - MFT_REF mref; - unsigned long dent_ino; - int uname_len; - - ntfs_debug("Looking up %pd in directory inode 0x%lx.", - dent, dir_ino->i_ino); - /* Convert the name of the dentry to Unicode. */ - uname_len = ntfs_nlstoucs(vol, dent->d_name.name, dent->d_name.len, - &uname); - if (uname_len < 0) { - if (uname_len != -ENAMETOOLONG) - ntfs_error(vol->sb, "Failed to convert name to " - "Unicode."); - return ERR_PTR(uname_len); - } - mref = ntfs_lookup_inode_by_name(NTFS_I(dir_ino), uname, uname_len, - &name); - kmem_cache_free(ntfs_name_cache, uname); - if (!IS_ERR_MREF(mref)) { - dent_ino = MREF(mref); - ntfs_debug("Found inode 0x%lx. Calling ntfs_iget.", dent_ino); - dent_inode = ntfs_iget(vol->sb, dent_ino); - if (!IS_ERR(dent_inode)) { - /* Consistency check. */ - if (is_bad_inode(dent_inode) || MSEQNO(mref) == - NTFS_I(dent_inode)->seq_no || - dent_ino == FILE_MFT) { - /* Perfect WIN32/POSIX match. -- Case 1. */ - if (!name) { - ntfs_debug("Done. (Case 1.)"); - return d_splice_alias(dent_inode, dent); - } - /* - * We are too indented. Handle imperfect - * matches and short file names further below. - */ - goto handle_name; - } - ntfs_error(vol->sb, "Found stale reference to inode " - "0x%lx (reference sequence number = " - "0x%x, inode sequence number = 0x%x), " - "returning -EIO. Run chkdsk.", - dent_ino, MSEQNO(mref), - NTFS_I(dent_inode)->seq_no); - iput(dent_inode); - dent_inode = ERR_PTR(-EIO); - } else - ntfs_error(vol->sb, "ntfs_iget(0x%lx) failed with " - "error code %li.", dent_ino, - PTR_ERR(dent_inode)); - kfree(name); - /* Return the error code. */ - return ERR_CAST(dent_inode); - } - /* It is guaranteed that @name is no longer allocated at this point. */ - if (MREF_ERR(mref) == -ENOENT) { - ntfs_debug("Entry was not found, adding negative dentry."); - /* The dcache will handle negative entries. */ - d_add(dent, NULL); - ntfs_debug("Done."); - return NULL; - } - ntfs_error(vol->sb, "ntfs_lookup_ino_by_name() failed with error " - "code %i.", -MREF_ERR(mref)); - return ERR_PTR(MREF_ERR(mref)); - // TODO: Consider moving this lot to a separate function! (AIA) -handle_name: - { - MFT_RECORD *m; - ntfs_attr_search_ctx *ctx; - ntfs_inode *ni = NTFS_I(dent_inode); - int err; - struct qstr nls_name; - - nls_name.name = NULL; - if (name->type != FILE_NAME_DOS) { /* Case 2. */ - ntfs_debug("Case 2."); - nls_name.len = (unsigned)ntfs_ucstonls(vol, - (ntfschar*)&name->name, name->len, - (unsigned char**)&nls_name.name, 0); - kfree(name); - } else /* if (name->type == FILE_NAME_DOS) */ { /* Case 3. */ - FILE_NAME_ATTR *fn; - - ntfs_debug("Case 3."); - kfree(name); - - /* Find the WIN32 name corresponding to the matched DOS name. */ - ni = NTFS_I(dent_inode); - m = map_mft_record(ni); - if (IS_ERR(m)) { - err = PTR_ERR(m); - m = NULL; - ctx = NULL; - goto err_out; - } - ctx = ntfs_attr_get_search_ctx(ni, m); - if (unlikely(!ctx)) { - err = -ENOMEM; - goto err_out; - } - do { - ATTR_RECORD *a; - u32 val_len; - - err = ntfs_attr_lookup(AT_FILE_NAME, NULL, 0, 0, 0, - NULL, 0, ctx); - if (unlikely(err)) { - ntfs_error(vol->sb, "Inode corrupt: No WIN32 " - "namespace counterpart to DOS " - "file name. Run chkdsk."); - if (err == -ENOENT) - err = -EIO; - goto err_out; - } - /* Consistency checks. */ - a = ctx->attr; - if (a->non_resident || a->flags) - goto eio_err_out; - val_len = le32_to_cpu(a->data.resident.value_length); - if (le16_to_cpu(a->data.resident.value_offset) + - val_len > le32_to_cpu(a->length)) - goto eio_err_out; - fn = (FILE_NAME_ATTR*)((u8*)ctx->attr + le16_to_cpu( - ctx->attr->data.resident.value_offset)); - if ((u32)(fn->file_name_length * sizeof(ntfschar) + - sizeof(FILE_NAME_ATTR)) > val_len) - goto eio_err_out; - } while (fn->file_name_type != FILE_NAME_WIN32); - - /* Convert the found WIN32 name to current NLS code page. */ - nls_name.len = (unsigned)ntfs_ucstonls(vol, - (ntfschar*)&fn->file_name, fn->file_name_length, - (unsigned char**)&nls_name.name, 0); - - ntfs_attr_put_search_ctx(ctx); - unmap_mft_record(ni); - } - m = NULL; - ctx = NULL; - - /* Check if a conversion error occurred. */ - if ((signed)nls_name.len < 0) { - err = (signed)nls_name.len; - goto err_out; - } - nls_name.hash = full_name_hash(dent, nls_name.name, nls_name.len); - - dent = d_add_ci(dent, dent_inode, &nls_name); - kfree(nls_name.name); - return dent; - -eio_err_out: - ntfs_error(vol->sb, "Illegal file name attribute. Run chkdsk."); - err = -EIO; -err_out: - if (ctx) - ntfs_attr_put_search_ctx(ctx); - if (m) - unmap_mft_record(ni); - iput(dent_inode); - ntfs_error(vol->sb, "Failed, returning error code %i.", err); - return ERR_PTR(err); - } -} - -/* - * Inode operations for directories. - */ -const struct inode_operations ntfs_dir_inode_ops = { - .lookup = ntfs_lookup, /* VFS: Lookup directory. */ -}; - -/** - * ntfs_get_parent - find the dentry of the parent of a given directory dentry - * @child_dent: dentry of the directory whose parent directory to find - * - * Find the dentry for the parent directory of the directory specified by the - * dentry @child_dent. This function is called from - * fs/exportfs/expfs.c::find_exported_dentry() which in turn is called from the - * default ->decode_fh() which is export_decode_fh() in the same file. - * - * The code is based on the ext3 ->get_parent() implementation found in - * fs/ext3/namei.c::ext3_get_parent(). - * - * Note: ntfs_get_parent() is called with @d_inode(child_dent)->i_mutex down. - * - * Return the dentry of the parent directory on success or the error code on - * error (IS_ERR() is true). - */ -static struct dentry *ntfs_get_parent(struct dentry *child_dent) -{ - struct inode *vi = d_inode(child_dent); - ntfs_inode *ni = NTFS_I(vi); - MFT_RECORD *mrec; - ntfs_attr_search_ctx *ctx; - ATTR_RECORD *attr; - FILE_NAME_ATTR *fn; - unsigned long parent_ino; - int err; - - ntfs_debug("Entering for inode 0x%lx.", vi->i_ino); - /* Get the mft record of the inode belonging to the child dentry. */ - mrec = map_mft_record(ni); - if (IS_ERR(mrec)) - return ERR_CAST(mrec); - /* Find the first file name attribute in the mft record. */ - ctx = ntfs_attr_get_search_ctx(ni, mrec); - if (unlikely(!ctx)) { - unmap_mft_record(ni); - return ERR_PTR(-ENOMEM); - } -try_next: - err = ntfs_attr_lookup(AT_FILE_NAME, NULL, 0, CASE_SENSITIVE, 0, NULL, - 0, ctx); - if (unlikely(err)) { - ntfs_attr_put_search_ctx(ctx); - unmap_mft_record(ni); - if (err == -ENOENT) - ntfs_error(vi->i_sb, "Inode 0x%lx does not have a " - "file name attribute. Run chkdsk.", - vi->i_ino); - return ERR_PTR(err); - } - attr = ctx->attr; - if (unlikely(attr->non_resident)) - goto try_next; - fn = (FILE_NAME_ATTR *)((u8 *)attr + - le16_to_cpu(attr->data.resident.value_offset)); - if (unlikely((u8 *)fn + le32_to_cpu(attr->data.resident.value_length) > - (u8*)attr + le32_to_cpu(attr->length))) - goto try_next; - /* Get the inode number of the parent directory. */ - parent_ino = MREF_LE(fn->parent_directory); - /* Release the search context and the mft record of the child. */ - ntfs_attr_put_search_ctx(ctx); - unmap_mft_record(ni); - - return d_obtain_alias(ntfs_iget(vi->i_sb, parent_ino)); -} - -static struct inode *ntfs_nfs_get_inode(struct super_block *sb, - u64 ino, u32 generation) -{ - struct inode *inode; - - inode = ntfs_iget(sb, ino); - if (!IS_ERR(inode)) { - if (is_bad_inode(inode) || inode->i_generation != generation) { - iput(inode); - inode = ERR_PTR(-ESTALE); - } - } - - return inode; -} - -static struct dentry *ntfs_fh_to_dentry(struct super_block *sb, struct fid *fid, - int fh_len, int fh_type) -{ - return generic_fh_to_dentry(sb, fid, fh_len, fh_type, - ntfs_nfs_get_inode); -} - -static struct dentry *ntfs_fh_to_parent(struct super_block *sb, struct fid *fid, - int fh_len, int fh_type) -{ - return generic_fh_to_parent(sb, fid, fh_len, fh_type, - ntfs_nfs_get_inode); -} - -/* - * Export operations allowing NFS exporting of mounted NTFS partitions. - * - * We use the default ->encode_fh() for now. Note that they - * use 32 bits to store the inode number which is an unsigned long so on 64-bit - * architectures is usually 64 bits so it would all fail horribly on huge - * volumes. I guess we need to define our own encode and decode fh functions - * that store 64-bit inode numbers at some point but for now we will ignore the - * problem... - * - * We also use the default ->get_name() helper (used by ->decode_fh() via - * fs/exportfs/expfs.c::find_exported_dentry()) as that is completely fs - * independent. - * - * The default ->get_parent() just returns -EACCES so we have to provide our - * own and the default ->get_dentry() is incompatible with NTFS due to not - * allowing the inode number 0 which is used in NTFS for the system file $MFT - * and due to using iget() whereas NTFS needs ntfs_iget(). - */ -const struct export_operations ntfs_export_ops = { - .encode_fh = generic_encode_ino32_fh, - .get_parent = ntfs_get_parent, /* Find the parent of a given - directory. */ - .fh_to_dentry = ntfs_fh_to_dentry, - .fh_to_parent = ntfs_fh_to_parent, -}; |