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author | Konstantin Komarov <almaz.alexandrovich@paragon-software.com> | 2021-08-13 17:21:29 +0300 |
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committer | Konstantin Komarov <almaz.alexandrovich@paragon-software.com> | 2021-08-13 07:55:49 -0700 |
commit | 4342306f0f0d5ff4315a204d315c1b51b914fca5 (patch) | |
tree | 331c87db643430a51e9d5a7ad629ca16a5f5d31e /fs/ntfs3/dir.c | |
parent | 3f3b442b5ad2455507c9bfdacf39a3792eb3a6d0 (diff) | |
download | linux-4342306f0f0d5ff4315a204d315c1b51b914fca5.tar.bz2 |
fs/ntfs3: Add file operations and implementation
This adds file operations and implementation
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Diffstat (limited to 'fs/ntfs3/dir.c')
-rw-r--r-- | fs/ntfs3/dir.c | 596 |
1 files changed, 596 insertions, 0 deletions
diff --git a/fs/ntfs3/dir.c b/fs/ntfs3/dir.c new file mode 100644 index 000000000000..d36d7fbc2b1d --- /dev/null +++ b/fs/ntfs3/dir.c @@ -0,0 +1,596 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * + * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved. + * + * directory handling functions for ntfs-based filesystems + * + */ +#include <linux/blkdev.h> +#include <linux/buffer_head.h> +#include <linux/fs.h> +#include <linux/iversion.h> +#include <linux/nls.h> + +#include "debug.h" +#include "ntfs.h" +#include "ntfs_fs.h" + +/* + * Convert little endian utf16 to nls string + */ +int ntfs_utf16_to_nls(struct ntfs_sb_info *sbi, const struct le_str *uni, + u8 *buf, int buf_len) +{ + int ret, uni_len, warn; + const __le16 *ip; + u8 *op; + struct nls_table *nls = sbi->options.nls; + + static_assert(sizeof(wchar_t) == sizeof(__le16)); + + if (!nls) { + /* utf16 -> utf8 */ + ret = utf16s_to_utf8s((wchar_t *)uni->name, uni->len, + UTF16_LITTLE_ENDIAN, buf, buf_len); + buf[ret] = '\0'; + return ret; + } + + ip = uni->name; + op = buf; + uni_len = uni->len; + warn = 0; + + while (uni_len--) { + u16 ec; + int charlen; + char dump[5]; + + if (buf_len < NLS_MAX_CHARSET_SIZE) { + ntfs_warn(sbi->sb, + "filename was truncated while converting."); + break; + } + + ec = le16_to_cpu(*ip++); + charlen = nls->uni2char(ec, op, buf_len); + + if (charlen > 0) { + op += charlen; + buf_len -= charlen; + continue; + } + + *op++ = '_'; + buf_len -= 1; + if (warn) + continue; + + warn = 1; + hex_byte_pack(&dump[0], ec >> 8); + hex_byte_pack(&dump[2], ec); + dump[4] = 0; + + ntfs_err(sbi->sb, "failed to convert \"%s\" to %s", dump, + nls->charset); + } + + *op = '\0'; + return op - buf; +} + +// clang-format off +#define PLANE_SIZE 0x00010000 + +#define SURROGATE_PAIR 0x0000d800 +#define SURROGATE_LOW 0x00000400 +#define SURROGATE_BITS 0x000003ff +// clang-format on + +/* + * modified version of put_utf16 from fs/nls/nls_base.c + * is sparse warnings free + */ +static inline void put_utf16(wchar_t *s, unsigned int c, + enum utf16_endian endian) +{ + static_assert(sizeof(wchar_t) == sizeof(__le16)); + static_assert(sizeof(wchar_t) == sizeof(__be16)); + + switch (endian) { + default: + *s = (wchar_t)c; + break; + case UTF16_LITTLE_ENDIAN: + *(__le16 *)s = __cpu_to_le16(c); + break; + case UTF16_BIG_ENDIAN: + *(__be16 *)s = __cpu_to_be16(c); + break; + } +} + +/* + * modified version of 'utf8s_to_utf16s' allows to + * detect -ENAMETOOLONG without writing out of expected maximum + */ +static int _utf8s_to_utf16s(const u8 *s, int inlen, enum utf16_endian endian, + wchar_t *pwcs, int maxout) +{ + u16 *op; + int size; + unicode_t u; + + op = pwcs; + while (inlen > 0 && *s) { + if (*s & 0x80) { + size = utf8_to_utf32(s, inlen, &u); + if (size < 0) + return -EINVAL; + s += size; + inlen -= size; + + if (u >= PLANE_SIZE) { + if (maxout < 2) + return -ENAMETOOLONG; + + u -= PLANE_SIZE; + put_utf16(op++, + SURROGATE_PAIR | + ((u >> 10) & SURROGATE_BITS), + endian); + put_utf16(op++, + SURROGATE_PAIR | SURROGATE_LOW | + (u & SURROGATE_BITS), + endian); + maxout -= 2; + } else { + if (maxout < 1) + return -ENAMETOOLONG; + + put_utf16(op++, u, endian); + maxout--; + } + } else { + if (maxout < 1) + return -ENAMETOOLONG; + + put_utf16(op++, *s++, endian); + inlen--; + maxout--; + } + } + return op - pwcs; +} + +/* + * Convert input string to utf16 + * + * name, name_len - input name + * uni, max_ulen - destination memory + * endian - endian of target utf16 string + * + * This function is called: + * - to create ntfs name + * - to create symlink + * + * returns utf16 string length or error (if negative) + */ +int ntfs_nls_to_utf16(struct ntfs_sb_info *sbi, const u8 *name, u32 name_len, + struct cpu_str *uni, u32 max_ulen, + enum utf16_endian endian) +{ + int ret, slen; + const u8 *end; + struct nls_table *nls = sbi->options.nls; + u16 *uname = uni->name; + + static_assert(sizeof(wchar_t) == sizeof(u16)); + + if (!nls) { + /* utf8 -> utf16 */ + ret = _utf8s_to_utf16s(name, name_len, endian, uname, max_ulen); + uni->len = ret; + return ret; + } + + for (ret = 0, end = name + name_len; name < end; ret++, name += slen) { + if (ret >= max_ulen) + return -ENAMETOOLONG; + + slen = nls->char2uni(name, end - name, uname + ret); + if (!slen) + return -EINVAL; + if (slen < 0) + return slen; + } + +#ifdef __BIG_ENDIAN + if (endian == UTF16_LITTLE_ENDIAN) { + int i = ret; + + while (i--) { + __cpu_to_le16s(uname); + uname++; + } + } +#else + if (endian == UTF16_BIG_ENDIAN) { + int i = ret; + + while (i--) { + __cpu_to_be16s(uname); + uname++; + } + } +#endif + + uni->len = ret; + return ret; +} + +/* helper function */ +struct inode *dir_search_u(struct inode *dir, const struct cpu_str *uni, + struct ntfs_fnd *fnd) +{ + int err = 0; + struct super_block *sb = dir->i_sb; + struct ntfs_sb_info *sbi = sb->s_fs_info; + struct ntfs_inode *ni = ntfs_i(dir); + struct NTFS_DE *e; + int diff; + struct inode *inode = NULL; + struct ntfs_fnd *fnd_a = NULL; + + if (!fnd) { + fnd_a = fnd_get(); + if (!fnd_a) { + err = -ENOMEM; + goto out; + } + fnd = fnd_a; + } + + err = indx_find(&ni->dir, ni, NULL, uni, 0, sbi, &diff, &e, fnd); + + if (err) + goto out; + + if (diff) { + err = -ENOENT; + goto out; + } + + inode = ntfs_iget5(sb, &e->ref, uni); + if (!IS_ERR(inode) && is_bad_inode(inode)) { + iput(inode); + err = -EINVAL; + } +out: + fnd_put(fnd_a); + + return err == -ENOENT ? NULL : err ? ERR_PTR(err) : inode; +} + +static inline int ntfs_filldir(struct ntfs_sb_info *sbi, struct ntfs_inode *ni, + const struct NTFS_DE *e, u8 *name, + struct dir_context *ctx) +{ + const struct ATTR_FILE_NAME *fname; + unsigned long ino; + int name_len; + u32 dt_type; + + fname = Add2Ptr(e, sizeof(struct NTFS_DE)); + + if (fname->type == FILE_NAME_DOS) + return 0; + + if (!mi_is_ref(&ni->mi, &fname->home)) + return 0; + + ino = ino_get(&e->ref); + + if (ino == MFT_REC_ROOT) + return 0; + + /* Skip meta files ( unless option to show metafiles is set ) */ + if (!sbi->options.showmeta && ntfs_is_meta_file(sbi, ino)) + return 0; + + if (sbi->options.nohidden && (fname->dup.fa & FILE_ATTRIBUTE_HIDDEN)) + return 0; + + name_len = ntfs_utf16_to_nls(sbi, (struct le_str *)&fname->name_len, + name, PATH_MAX); + if (name_len <= 0) { + ntfs_warn(sbi->sb, "failed to convert name for inode %lx.", + ino); + return 0; + } + + dt_type = (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY) ? DT_DIR : DT_REG; + + return !dir_emit(ctx, (s8 *)name, name_len, ino, dt_type); +} + +/* + * ntfs_read_hdr + * + * helper function 'ntfs_readdir' + */ +static int ntfs_read_hdr(struct ntfs_sb_info *sbi, struct ntfs_inode *ni, + const struct INDEX_HDR *hdr, u64 vbo, u64 pos, + u8 *name, struct dir_context *ctx) +{ + int err; + const struct NTFS_DE *e; + u32 e_size; + u32 end = le32_to_cpu(hdr->used); + u32 off = le32_to_cpu(hdr->de_off); + + for (;; off += e_size) { + if (off + sizeof(struct NTFS_DE) > end) + return -1; + + e = Add2Ptr(hdr, off); + e_size = le16_to_cpu(e->size); + if (e_size < sizeof(struct NTFS_DE) || off + e_size > end) + return -1; + + if (de_is_last(e)) + return 0; + + /* Skip already enumerated*/ + if (vbo + off < pos) + continue; + + if (le16_to_cpu(e->key_size) < SIZEOF_ATTRIBUTE_FILENAME) + return -1; + + ctx->pos = vbo + off; + + /* Submit the name to the filldir callback. */ + err = ntfs_filldir(sbi, ni, e, name, ctx); + if (err) + return err; + } +} + +/* + * file_operations::iterate_shared + * + * Use non sorted enumeration. + * We have an example of broken volume where sorted enumeration + * counts each name twice + */ +static int ntfs_readdir(struct file *file, struct dir_context *ctx) +{ + const struct INDEX_ROOT *root; + u64 vbo; + size_t bit; + loff_t eod; + int err = 0; + struct inode *dir = file_inode(file); + struct ntfs_inode *ni = ntfs_i(dir); + struct super_block *sb = dir->i_sb; + struct ntfs_sb_info *sbi = sb->s_fs_info; + loff_t i_size = i_size_read(dir); + u32 pos = ctx->pos; + u8 *name = NULL; + struct indx_node *node = NULL; + u8 index_bits = ni->dir.index_bits; + + /* name is a buffer of PATH_MAX length */ + static_assert(NTFS_NAME_LEN * 4 < PATH_MAX); + + eod = i_size + sbi->record_size; + + if (pos >= eod) + return 0; + + if (!dir_emit_dots(file, ctx)) + return 0; + + /* allocate PATH_MAX bytes */ + name = __getname(); + if (!name) + return -ENOMEM; + + if (!ni->mi_loaded && ni->attr_list.size) { + /* + * directory inode is locked for read + * load all subrecords to avoid 'write' access to 'ni' during + * directory reading + */ + ni_lock(ni); + if (!ni->mi_loaded && ni->attr_list.size) { + err = ni_load_all_mi(ni); + if (!err) + ni->mi_loaded = true; + } + ni_unlock(ni); + if (err) + goto out; + } + + root = indx_get_root(&ni->dir, ni, NULL, NULL); + if (!root) { + err = -EINVAL; + goto out; + } + + if (pos >= sbi->record_size) { + bit = (pos - sbi->record_size) >> index_bits; + } else { + err = ntfs_read_hdr(sbi, ni, &root->ihdr, 0, pos, name, ctx); + if (err) + goto out; + bit = 0; + } + + if (!i_size) { + ctx->pos = eod; + goto out; + } + + for (;;) { + vbo = (u64)bit << index_bits; + if (vbo >= i_size) { + ctx->pos = eod; + goto out; + } + + err = indx_used_bit(&ni->dir, ni, &bit); + if (err) + goto out; + + if (bit == MINUS_ONE_T) { + ctx->pos = eod; + goto out; + } + + vbo = (u64)bit << index_bits; + if (vbo >= i_size) { + ntfs_inode_err(dir, "Looks like your dir is corrupt"); + err = -EINVAL; + goto out; + } + + err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits, + &node); + if (err) + goto out; + + err = ntfs_read_hdr(sbi, ni, &node->index->ihdr, + vbo + sbi->record_size, pos, name, ctx); + if (err) + goto out; + + bit += 1; + } + +out: + + __putname(name); + put_indx_node(node); + + if (err == -ENOENT) { + err = 0; + ctx->pos = pos; + } + + return err; +} + +static int ntfs_dir_count(struct inode *dir, bool *is_empty, size_t *dirs, + size_t *files) +{ + int err = 0; + struct ntfs_inode *ni = ntfs_i(dir); + struct NTFS_DE *e = NULL; + struct INDEX_ROOT *root; + struct INDEX_HDR *hdr; + const struct ATTR_FILE_NAME *fname; + u32 e_size, off, end; + u64 vbo = 0; + size_t drs = 0, fles = 0, bit = 0; + loff_t i_size = ni->vfs_inode.i_size; + struct indx_node *node = NULL; + u8 index_bits = ni->dir.index_bits; + + if (is_empty) + *is_empty = true; + + root = indx_get_root(&ni->dir, ni, NULL, NULL); + if (!root) + return -EINVAL; + + hdr = &root->ihdr; + + for (;;) { + end = le32_to_cpu(hdr->used); + off = le32_to_cpu(hdr->de_off); + + for (; off + sizeof(struct NTFS_DE) <= end; off += e_size) { + e = Add2Ptr(hdr, off); + e_size = le16_to_cpu(e->size); + if (e_size < sizeof(struct NTFS_DE) || + off + e_size > end) + break; + + if (de_is_last(e)) + break; + + fname = de_get_fname(e); + if (!fname) + continue; + + if (fname->type == FILE_NAME_DOS) + continue; + + if (is_empty) { + *is_empty = false; + if (!dirs && !files) + goto out; + } + + if (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY) + drs += 1; + else + fles += 1; + } + + if (vbo >= i_size) + goto out; + + err = indx_used_bit(&ni->dir, ni, &bit); + if (err) + goto out; + + if (bit == MINUS_ONE_T) + goto out; + + vbo = (u64)bit << index_bits; + if (vbo >= i_size) + goto out; + + err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits, + &node); + if (err) + goto out; + + hdr = &node->index->ihdr; + bit += 1; + vbo = (u64)bit << ni->dir.idx2vbn_bits; + } + +out: + put_indx_node(node); + if (dirs) + *dirs = drs; + if (files) + *files = fles; + + return err; +} + +bool dir_is_empty(struct inode *dir) +{ + bool is_empty = false; + + ntfs_dir_count(dir, &is_empty, NULL, NULL); + + return is_empty; +} + +// clang-format off +const struct file_operations ntfs_dir_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate_shared = ntfs_readdir, + .fsync = generic_file_fsync, + .open = ntfs_file_open, +}; +// clang-format on |