/* * linux/fs/vfat/namei.c * * Written 1992,1993 by Werner Almesberger * * Windows95/Windows NT compatible extended MSDOS filesystem * by Gordon Chaffee Copyright (C) 1995. Send bug reports for the * VFAT filesystem to <chaffee@cs.berkeley.edu>. Specify * what file operation caused you trouble and if you can duplicate * the problem, send a script that demonstrates it. * * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de> * * Support Multibyte characters and cleanup by * OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> */ #include <linux/module.h> #include <linux/ctype.h> #include <linux/slab.h> #include <linux/namei.h> #include <linux/kernel.h> #include <linux/iversion.h> #include "fat.h" static inline unsigned long vfat_d_version(struct dentry *dentry) { return (unsigned long) dentry->d_fsdata; } static inline void vfat_d_version_set(struct dentry *dentry, unsigned long version) { dentry->d_fsdata = (void *) version; } /* * If new entry was created in the parent, it could create the 8.3 * alias (the shortname of logname). So, the parent may have the * negative-dentry which matches the created 8.3 alias. * * If it happened, the negative dentry isn't actually negative * anymore. So, drop it. */ static int vfat_revalidate_shortname(struct dentry *dentry) { int ret = 1; spin_lock(&dentry->d_lock); if (!inode_eq_iversion(d_inode(dentry->d_parent), vfat_d_version(dentry))) ret = 0; spin_unlock(&dentry->d_lock); return ret; } static int vfat_revalidate(struct dentry *dentry, unsigned int flags) { if (flags & LOOKUP_RCU) return -ECHILD; /* This is not negative dentry. Always valid. */ if (d_really_is_positive(dentry)) return 1; return vfat_revalidate_shortname(dentry); } static int vfat_revalidate_ci(struct dentry *dentry, unsigned int flags) { if (flags & LOOKUP_RCU) return -ECHILD; /* * This is not negative dentry. Always valid. * * Note, rename() to existing directory entry will have ->d_inode, * and will use existing name which isn't specified name by user. * * We may be able to drop this positive dentry here. But dropping * positive dentry isn't good idea. So it's unsupported like * rename("filename", "FILENAME") for now. */ if (d_really_is_positive(dentry)) return 1; /* * This may be nfsd (or something), anyway, we can't see the * intent of this. So, since this can be for creation, drop it. */ if (!flags) return 0; /* * Drop the negative dentry, in order to make sure to use the * case sensitive name which is specified by user if this is * for creation. */ if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) return 0; return vfat_revalidate_shortname(dentry); } /* returns the length of a struct qstr, ignoring trailing dots */ static unsigned int __vfat_striptail_len(unsigned int len, const char *name) { while (len && name[len - 1] == '.') len--; return len; } static unsigned int vfat_striptail_len(const struct qstr *qstr) { return __vfat_striptail_len(qstr->len, qstr->name); } /* * Compute the hash for the vfat name corresponding to the dentry. * Note: if the name is invalid, we leave the hash code unchanged so * that the existing dentry can be used. The vfat fs routines will * return ENOENT or EINVAL as appropriate. */ static int vfat_hash(const struct dentry *dentry, struct qstr *qstr) { qstr->hash = full_name_hash(dentry, qstr->name, vfat_striptail_len(qstr)); return 0; } /* * Compute the hash for the vfat name corresponding to the dentry. * Note: if the name is invalid, we leave the hash code unchanged so * that the existing dentry can be used. The vfat fs routines will * return ENOENT or EINVAL as appropriate. */ static int vfat_hashi(const struct dentry *dentry, struct qstr *qstr) { struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; const unsigned char *name; unsigned int len; unsigned long hash; name = qstr->name; len = vfat_striptail_len(qstr); hash = init_name_hash(dentry); while (len--) hash = partial_name_hash(nls_tolower(t, *name++), hash); qstr->hash = end_name_hash(hash); return 0; } /* * Case insensitive compare of two vfat names. */ static int vfat_cmpi(const struct dentry *dentry, unsigned int len, const char *str, const struct qstr *name) { struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; unsigned int alen, blen; /* A filename cannot end in '.' or we treat it like it has none */ alen = vfat_striptail_len(name); blen = __vfat_striptail_len(len, str); if (alen == blen) { if (nls_strnicmp(t, name->name, str, alen) == 0) return 0; } return 1; } /* * Case sensitive compare of two vfat names. */ static int vfat_cmp(const struct dentry *dentry, unsigned int len, const char *str, const struct qstr *name) { unsigned int alen, blen; /* A filename cannot end in '.' or we treat it like it has none */ alen = vfat_striptail_len(name); blen = __vfat_striptail_len(len, str); if (alen == blen) { if (strncmp(name->name, str, alen) == 0) return 0; } return 1; } static const struct dentry_operations vfat_ci_dentry_ops = { .d_revalidate = vfat_revalidate_ci, .d_hash = vfat_hashi, .d_compare = vfat_cmpi, }; static const struct dentry_operations vfat_dentry_ops = { .d_revalidate = vfat_revalidate, .d_hash = vfat_hash, .d_compare = vfat_cmp, }; /* Characters that are undesirable in an MS-DOS file name */ static inline wchar_t vfat_bad_char(wchar_t w) { return (w < 0x0020) || (w == '*') || (w == '?') || (w == '<') || (w == '>') || (w == '|') || (w == '"') || (w == ':') || (w == '/') || (w == '\\'); } static inline wchar_t vfat_replace_char(wchar_t w) { return (w == '[') || (w == ']') || (w == ';') || (w == ',') || (w == '+') || (w == '='); } static wchar_t vfat_skip_char(wchar_t w) { return (w == '.') || (w == ' '); } static inline int vfat_is_used_badchars(const wchar_t *s, int len) { int i; for (i = 0; i < len; i++) if (vfat_bad_char(s[i])) return -EINVAL; if (s[i - 1] == ' ') /* last character cannot be space */ return -EINVAL; return 0; } static int vfat_find_form(struct inode *dir, unsigned char *name) { struct fat_slot_info sinfo; int err = fat_scan(dir, name, &sinfo); if (err) return -ENOENT; brelse(sinfo.bh); return 0; } /* * 1) Valid characters for the 8.3 format alias are any combination of * letters, uppercase alphabets, digits, any of the * following special characters: * $ % ' ` - @ { } ~ ! # ( ) & _ ^ * In this case Longfilename is not stored in disk. * * WinNT's Extension: * File name and extension name is contain uppercase/lowercase * only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT. * * 2) File name is 8.3 format, but it contain the uppercase and * lowercase char, muliti bytes char, etc. In this case numtail is not * added, but Longfilename is stored. * * 3) When the one except for the above, or the following special * character are contained: * . [ ] ; , + = * numtail is added, and Longfilename must be stored in disk . */ struct shortname_info { unsigned char lower:1, upper:1, valid:1; }; #define INIT_SHORTNAME_INFO(x) do { \ (x)->lower = 1; \ (x)->upper = 1; \ (x)->valid = 1; \ } while (0) static inline int to_shortname_char(struct nls_table *nls, unsigned char *buf, int buf_size, wchar_t *src, struct shortname_info *info) { int len; if (vfat_skip_char(*src)) { info->valid = 0; return 0; } if (vfat_replace_char(*src)) { info->valid = 0; buf[0] = '_'; return 1; } len = nls->uni2char(*src, buf, buf_size); if (len <= 0) { info->valid = 0; buf[0] = '_'; len = 1; } else if (len == 1) { unsigned char prev = buf[0]; if (buf[0] >= 0x7F) { info->lower = 0; info->upper = 0; } buf[0] = nls_toupper(nls, buf[0]); if (isalpha(buf[0])) { if (buf[0] == prev) info->lower = 0; else info->upper = 0; } } else { info->lower = 0; info->upper = 0; } return len; } /* * Given a valid longname, create a unique shortname. Make sure the * shortname does not exist * Returns negative number on error, 0 for a normal * return, and 1 for valid shortname */ static int vfat_create_shortname(struct inode *dir, struct nls_table *nls, wchar_t *uname, int ulen, unsigned char *name_res, unsigned char *lcase) { struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options; wchar_t *ip, *ext_start, *end, *name_start; unsigned char base[9], ext[4], buf[5], *p; unsigned char charbuf[NLS_MAX_CHARSET_SIZE]; int chl, chi; int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen; int is_shortname; struct shortname_info base_info, ext_info; is_shortname = 1; INIT_SHORTNAME_INFO(&base_info); INIT_SHORTNAME_INFO(&ext_info); /* Now, we need to create a shortname from the long name */ ext_start = end = &uname[ulen]; while (--ext_start >= uname) { if (*ext_start == 0x002E) { /* is `.' */ if (ext_start == end - 1) { sz = ulen; ext_start = NULL; } break; } } if (ext_start == uname - 1) { sz = ulen; ext_start = NULL; } else if (ext_start) { /* * Names which start with a dot could be just * an extension eg. "...test". In this case Win95 * uses the extension as the name and sets no extension. */ name_start = &uname[0]; while (name_start < ext_start) { if (!vfat_skip_char(*name_start)) break; name_start++; } if (name_start != ext_start) { sz = ext_start - uname; ext_start++; } else { sz = ulen; ext_start = NULL; } } numtail_baselen = 6; numtail2_baselen = 2; for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) { chl = to_shortname_char(nls, charbuf, sizeof(charbuf), ip, &base_info); if (chl == 0) continue; if (baselen < 2 && (baselen + chl) > 2) numtail2_baselen = baselen; if (baselen < 6 && (baselen + chl) > 6) numtail_baselen = baselen; for (chi = 0; chi < chl; chi++) { *p++ = charbuf[chi]; baselen++; if (baselen >= 8) break; } if (baselen >= 8) { if ((chi < chl - 1) || (ip + 1) - uname < sz) is_shortname = 0; break; } } if (baselen == 0) { return -EINVAL; } extlen = 0; if (ext_start) { for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) { chl = to_shortname_char(nls, charbuf, sizeof(charbuf), ip, &ext_info); if (chl == 0) continue; if ((extlen + chl) > 3) { is_shortname = 0; break; } for (chi = 0; chi < chl; chi++) { *p++ = charbuf[chi]; extlen++; } if (extlen >= 3) { if (ip + 1 != end) is_shortname = 0; break; } } } ext[extlen] = '\0'; base[baselen] = '\0'; /* Yes, it can happen. ".\xe5" would do it. */ if (base[0] == DELETED_FLAG) base[0] = 0x05; /* OK, at this point we know that base is not longer than 8 symbols, * ext is not longer than 3, base is nonempty, both don't contain * any bad symbols (lowercase transformed to uppercase). */ memset(name_res, ' ', MSDOS_NAME); memcpy(name_res, base, baselen); memcpy(name_res + 8, ext, extlen); *lcase = 0; if (is_shortname && base_info.valid && ext_info.valid) { if (vfat_find_form(dir, name_res) == 0) return -EEXIST; if (opts->shortname & VFAT_SFN_CREATE_WIN95) { return (base_info.upper && ext_info.upper); } else if (opts->shortname & VFAT_SFN_CREATE_WINNT) { if ((base_info.upper || base_info.lower) && (ext_info.upper || ext_info.lower)) { if (!base_info.upper && base_info.lower) *lcase |= CASE_LOWER_BASE; if (!ext_info.upper && ext_info.lower) *lcase |= CASE_LOWER_EXT; return 1; } return 0; } else { BUG(); } } if (opts->numtail == 0) if (vfat_find_form(dir, name_res) < 0) return 0; /* * Try to find a unique extension. This used to * iterate through all possibilities sequentially, * but that gave extremely bad performance. Windows * only tries a few cases before using random * values for part of the base. */ if (baselen > 6) { baselen = numtail_baselen; name_res[7] = ' '; } name_res[baselen] = '~'; for (i = 1; i < 10; i++) { name_res[baselen + 1] = i + '0'; if (vfat_find_form(dir, name_res) < 0) return 0; } i = jiffies; sz = (jiffies >> 16) & 0x7; if (baselen > 2) { baselen = numtail2_baselen; name_res[7] = ' '; } name_res[baselen + 4] = '~'; name_res[baselen + 5] = '1' + sz; while (1) { snprintf(buf, sizeof(buf), "%04X", i & 0xffff); memcpy(&name_res[baselen], buf, 4); if (vfat_find_form(dir, name_res) < 0) break; i -= 11; } return 0; } /* Translate a string, including coded sequences into Unicode */ static int xlate_to_uni(const unsigned char *name, int len, unsigned char *outname, int *longlen, int *outlen, int escape, int utf8, struct nls_table *nls) { const unsigned char *ip; unsigned char *op; int i, fill; int charlen; if (utf8) { *outlen = utf8s_to_utf16s(name, len, UTF16_HOST_ENDIAN, (wchar_t *) outname, FAT_LFN_LEN + 2); if (*outlen < 0) return *outlen; else if (*outlen > FAT_LFN_LEN) return -ENAMETOOLONG; op = &outname[*outlen * sizeof(wchar_t)]; } else { for (i = 0, ip = name, op = outname, *outlen = 0; i < len && *outlen < FAT_LFN_LEN; *outlen += 1) { if (escape && (*ip == ':')) { u8 uc[2]; if (i > len - 5) return -EINVAL; if (hex2bin(uc, ip + 1, 2) < 0) return -EINVAL; *(wchar_t *)op = uc[0] << 8 | uc[1]; op += 2; ip += 5; i += 5; } else { charlen = nls->char2uni(ip, len - i, (wchar_t *)op); if (charlen < 0) return -EINVAL; ip += charlen; i += charlen; op += 2; } } if (i < len) return -ENAMETOOLONG; } *longlen = *outlen; if (*outlen % 13) { *op++ = 0; *op++ = 0; *outlen += 1; if (*outlen % 13) { fill = 13 - (*outlen % 13); for (i = 0; i < fill; i++) { *op++ = 0xff; *op++ = 0xff; } *outlen += fill; } } return 0; } static int vfat_build_slots(struct inode *dir, const unsigned char *name, int len, int is_dir, int cluster, struct timespec *ts, struct msdos_dir_slot *slots, int *nr_slots) { struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb); struct fat_mount_options *opts = &sbi->options; struct msdos_dir_slot *ps; struct msdos_dir_entry *de; unsigned char cksum, lcase; unsigned char msdos_name[MSDOS_NAME]; wchar_t *uname; __le16 time, date; u8 time_cs; int err, ulen, usize, i; loff_t offset; *nr_slots = 0; uname = __getname(); if (!uname) return -ENOMEM; err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize, opts->unicode_xlate, opts->utf8, sbi->nls_io); if (err) goto out_free; err = vfat_is_used_badchars(uname, ulen); if (err) goto out_free; err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen, msdos_name, &lcase); if (err < 0) goto out_free; else if (err == 1) { de = (struct msdos_dir_entry *)slots; err = 0; goto shortname; } /* build the entry of long file name */ cksum = fat_checksum(msdos_name); *nr_slots = usize / 13; for (ps = slots, i = *nr_slots; i > 0; i--, ps++) { ps->id = i; ps->attr = ATTR_EXT; ps->reserved = 0; ps->alias_checksum = cksum; ps->start = 0; offset = (i - 1) * 13; fatwchar_to16(ps->name0_4, uname + offset, 5); fatwchar_to16(ps->name5_10, uname + offset + 5, 6); fatwchar_to16(ps->name11_12, uname + offset + 11, 2); } slots[0].id |= 0x40; de = (struct msdos_dir_entry *)ps; shortname: /* build the entry of 8.3 alias name */ (*nr_slots)++; memcpy(de->name, msdos_name, MSDOS_NAME); de->attr = is_dir ? ATTR_DIR : ATTR_ARCH; de->lcase = lcase; fat_time_unix2fat(sbi, ts, &time, &date, &time_cs); de->time = de->ctime = time; de->date = de->cdate = de->adate = date; de->ctime_cs = time_cs; fat_set_start(de, cluster); de->size = 0; out_free: __putname(uname); return err; } static int vfat_add_entry(struct inode *dir, const struct qstr *qname, int is_dir, int cluster, struct timespec *ts, struct fat_slot_info *sinfo) { struct msdos_dir_slot *slots; unsigned int len; int err, nr_slots; len = vfat_striptail_len(qname); if (len == 0) return -ENOENT; slots = kmalloc_array(MSDOS_SLOTS, sizeof(*slots), GFP_NOFS); if (slots == NULL) return -ENOMEM; err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts, slots, &nr_slots); if (err) goto cleanup; err = fat_add_entries(dir, slots, nr_slots, sinfo); if (err) goto cleanup; /* update timestamp */ dir->i_ctime = dir->i_mtime = dir->i_atime = timespec_to_timespec64(*ts); if (IS_DIRSYNC(dir)) (void)fat_sync_inode(dir); else mark_inode_dirty(dir); cleanup: kfree(slots); return err; } static int vfat_find(struct inode *dir, const struct qstr *qname, struct fat_slot_info *sinfo) { unsigned int len = vfat_striptail_len(qname); if (len == 0) return -ENOENT; return fat_search_long(dir, qname->name, len, sinfo); } static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct super_block *sb = dir->i_sb; struct fat_slot_info sinfo; struct inode *inode; struct dentry *alias; int err; mutex_lock(&MSDOS_SB(sb)->s_lock); err = vfat_find(dir, &dentry->d_name, &sinfo); if (err) { if (err == -ENOENT) { inode = NULL; goto out; } goto error; } inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); brelse(sinfo.bh); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto error; } alias = d_find_alias(inode); /* * Checking "alias->d_parent == dentry->d_parent" to make sure * FS is not corrupted (especially double linked dir). */ if (alias && alias->d_parent == dentry->d_parent) { /* * This inode has non anonymous-DCACHE_DISCONNECTED * dentry. This means, the user did ->lookup() by an * another name (longname vs 8.3 alias of it) in past. * * Switch to new one for reason of locality if possible. */ if (!S_ISDIR(inode->i_mode)) d_move(alias, dentry); iput(inode); mutex_unlock(&MSDOS_SB(sb)->s_lock); return alias; } else dput(alias); out: mutex_unlock(&MSDOS_SB(sb)->s_lock); if (!inode) vfat_d_version_set(dentry, inode_query_iversion(dir)); return d_splice_alias(inode, dentry); error: mutex_unlock(&MSDOS_SB(sb)->s_lock); return ERR_PTR(err); } static int vfat_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { struct super_block *sb = dir->i_sb; struct inode *inode; struct fat_slot_info sinfo; struct timespec64 ts; struct timespec t; int err; mutex_lock(&MSDOS_SB(sb)->s_lock); ts = current_time(dir); t = timespec64_to_timespec(ts); err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &t, &sinfo); if (err) goto out; inode_inc_iversion(dir); inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); brelse(sinfo.bh); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out; } inode_inc_iversion(inode); inode->i_mtime = inode->i_atime = inode->i_ctime = ts; /* timestamp is already written, so mark_inode_dirty() is unneeded. */ d_instantiate(dentry, inode); out: mutex_unlock(&MSDOS_SB(sb)->s_lock); return err; } static int vfat_rmdir(struct inode *dir, struct dentry *dentry) { struct inode *inode = d_inode(dentry); struct super_block *sb = dir->i_sb; struct fat_slot_info sinfo; int err; mutex_lock(&MSDOS_SB(sb)->s_lock); err = fat_dir_empty(inode); if (err) goto out; err = vfat_find(dir, &dentry->d_name, &sinfo); if (err) goto out; err = fat_remove_entries(dir, &sinfo); /* and releases bh */ if (err) goto out; drop_nlink(dir); clear_nlink(inode); inode->i_mtime = inode->i_atime = current_time(inode); fat_detach(inode); vfat_d_version_set(dentry, inode_query_iversion(dir)); out: mutex_unlock(&MSDOS_SB(sb)->s_lock); return err; } static int vfat_unlink(struct inode *dir, struct dentry *dentry) { struct inode *inode = d_inode(dentry); struct super_block *sb = dir->i_sb; struct fat_slot_info sinfo; int err; mutex_lock(&MSDOS_SB(sb)->s_lock); err = vfat_find(dir, &dentry->d_name, &sinfo); if (err) goto out; err = fat_remove_entries(dir, &sinfo); /* and releases bh */ if (err) goto out; clear_nlink(inode); inode->i_mtime = inode->i_atime = current_time(inode); fat_detach(inode); vfat_d_version_set(dentry, inode_query_iversion(dir)); out: mutex_unlock(&MSDOS_SB(sb)->s_lock); return err; } static int vfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { struct super_block *sb = dir->i_sb; struct inode *inode; struct fat_slot_info sinfo; struct timespec64 ts; struct timespec t; int err, cluster; mutex_lock(&MSDOS_SB(sb)->s_lock); ts = current_time(dir); t = timespec64_to_timespec(ts); cluster = fat_alloc_new_dir(dir, &t); if (cluster < 0) { err = cluster; goto out; } err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &t, &sinfo); if (err) goto out_free; inode_inc_iversion(dir); inc_nlink(dir); inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); brelse(sinfo.bh); if (IS_ERR(inode)) { err = PTR_ERR(inode); /* the directory was completed, just return a error */ goto out; } inode_inc_iversion(inode); set_nlink(inode, 2); inode->i_mtime = inode->i_atime = inode->i_ctime = ts; /* timestamp is already written, so mark_inode_dirty() is unneeded. */ d_instantiate(dentry, inode); mutex_unlock(&MSDOS_SB(sb)->s_lock); return 0; out_free: fat_free_clusters(dir, cluster); out: mutex_unlock(&MSDOS_SB(sb)->s_lock); return err; } static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { struct buffer_head *dotdot_bh; struct msdos_dir_entry *dotdot_de; struct inode *old_inode, *new_inode; struct fat_slot_info old_sinfo, sinfo; struct timespec64 ts; struct timespec t; loff_t new_i_pos; int err, is_dir, update_dotdot, corrupt = 0; struct super_block *sb = old_dir->i_sb; if (flags & ~RENAME_NOREPLACE) return -EINVAL; old_sinfo.bh = sinfo.bh = dotdot_bh = NULL; old_inode = d_inode(old_dentry); new_inode = d_inode(new_dentry); mutex_lock(&MSDOS_SB(sb)->s_lock); err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo); if (err) goto out; is_dir = S_ISDIR(old_inode->i_mode); update_dotdot = (is_dir && old_dir != new_dir); if (update_dotdot) { if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) { err = -EIO; goto out; } } ts = current_time(old_dir); if (new_inode) { if (is_dir) { err = fat_dir_empty(new_inode); if (err) goto out; } new_i_pos = MSDOS_I(new_inode)->i_pos; fat_detach(new_inode); } else { t = timespec64_to_timespec(ts); err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0, &t, &sinfo); if (err) goto out; new_i_pos = sinfo.i_pos; } inode_inc_iversion(new_dir); fat_detach(old_inode); fat_attach(old_inode, new_i_pos); if (IS_DIRSYNC(new_dir)) { err = fat_sync_inode(old_inode); if (err) goto error_inode; } else mark_inode_dirty(old_inode); if (update_dotdot) { fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart); mark_buffer_dirty_inode(dotdot_bh, old_inode); if (IS_DIRSYNC(new_dir)) { err = sync_dirty_buffer(dotdot_bh); if (err) goto error_dotdot; } drop_nlink(old_dir); if (!new_inode) inc_nlink(new_dir); } err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */ old_sinfo.bh = NULL; if (err) goto error_dotdot; inode_inc_iversion(old_dir); old_dir->i_ctime = old_dir->i_mtime = ts; if (IS_DIRSYNC(old_dir)) (void)fat_sync_inode(old_dir); else mark_inode_dirty(old_dir); if (new_inode) { drop_nlink(new_inode); if (is_dir) drop_nlink(new_inode); new_inode->i_ctime = ts; } out: brelse(sinfo.bh); brelse(dotdot_bh); brelse(old_sinfo.bh); mutex_unlock(&MSDOS_SB(sb)->s_lock); return err; error_dotdot: /* data cluster is shared, serious corruption */ corrupt = 1; if (update_dotdot) { fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart); mark_buffer_dirty_inode(dotdot_bh, old_inode); corrupt |= sync_dirty_buffer(dotdot_bh); } error_inode: fat_detach(old_inode); fat_attach(old_inode, old_sinfo.i_pos); if (new_inode) { fat_attach(new_inode, new_i_pos); if (corrupt) corrupt |= fat_sync_inode(new_inode); } else { /* * If new entry was not sharing the data cluster, it * shouldn't be serious corruption. */ int err2 = fat_remove_entries(new_dir, &sinfo); if (corrupt) corrupt |= err2; sinfo.bh = NULL; } if (corrupt < 0) { fat_fs_error(new_dir->i_sb, "%s: Filesystem corrupted (i_pos %lld)", __func__, sinfo.i_pos); } goto out; } static const struct inode_operations vfat_dir_inode_operations = { .create = vfat_create, .lookup = vfat_lookup, .unlink = vfat_unlink, .mkdir = vfat_mkdir, .rmdir = vfat_rmdir, .rename = vfat_rename, .setattr = fat_setattr, .getattr = fat_getattr, }; static void setup(struct super_block *sb) { MSDOS_SB(sb)->dir_ops = &vfat_dir_inode_operations; if (MSDOS_SB(sb)->options.name_check != 's') sb->s_d_op = &vfat_ci_dentry_ops; else sb->s_d_op = &vfat_dentry_ops; } static int vfat_fill_super(struct super_block *sb, void *data, int silent) { return fat_fill_super(sb, data, silent, 1, setup); } static struct dentry *vfat_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { return mount_bdev(fs_type, flags, dev_name, data, vfat_fill_super); } static struct file_system_type vfat_fs_type = { .owner = THIS_MODULE, .name = "vfat", .mount = vfat_mount, .kill_sb = kill_block_super, .fs_flags = FS_REQUIRES_DEV, }; MODULE_ALIAS_FS("vfat"); static int __init init_vfat_fs(void) { return register_filesystem(&vfat_fs_type); } static void __exit exit_vfat_fs(void) { unregister_filesystem(&vfat_fs_type); } MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("VFAT filesystem support"); MODULE_AUTHOR("Gordon Chaffee"); module_init(init_vfat_fs) module_exit(exit_vfat_fs)