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![Linus Torvalds](/assets/img/avatar_default.png)
Instances either don't look at it at all (the majority of cases) or only want it to find the superblock (which can be had as dentry->d_sb). A few cases that want more are actually safe with dentry->d_inode - the only precaution needed is the check that it hadn't been replaced with NULL by rmdir() or by overwriting rename(), which case should be simply treated as cache miss. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1089 lines
26 KiB
C
1089 lines
26 KiB
C
/*
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* linux/fs/vfat/namei.c
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*
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* Written 1992,1993 by Werner Almesberger
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*
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* Windows95/Windows NT compatible extended MSDOS filesystem
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* by Gordon Chaffee Copyright (C) 1995. Send bug reports for the
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* VFAT filesystem to <chaffee@cs.berkeley.edu>. Specify
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* what file operation caused you trouble and if you can duplicate
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* the problem, send a script that demonstrates it.
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*
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* Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
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*
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* Support Multibyte characters and cleanup by
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* OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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*/
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#include <linux/module.h>
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#include <linux/jiffies.h>
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#include <linux/ctype.h>
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#include <linux/slab.h>
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#include <linux/buffer_head.h>
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#include <linux/namei.h>
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#include "fat.h"
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/*
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* If new entry was created in the parent, it could create the 8.3
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* alias (the shortname of logname). So, the parent may have the
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* negative-dentry which matches the created 8.3 alias.
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*
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* If it happened, the negative dentry isn't actually negative
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* anymore. So, drop it.
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*/
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static int vfat_revalidate_shortname(struct dentry *dentry)
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{
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int ret = 1;
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spin_lock(&dentry->d_lock);
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if (dentry->d_time != dentry->d_parent->d_inode->i_version)
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ret = 0;
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spin_unlock(&dentry->d_lock);
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return ret;
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}
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static int vfat_revalidate(struct dentry *dentry, unsigned int flags)
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{
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if (flags & LOOKUP_RCU)
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return -ECHILD;
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/* This is not negative dentry. Always valid. */
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if (dentry->d_inode)
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return 1;
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return vfat_revalidate_shortname(dentry);
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}
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static int vfat_revalidate_ci(struct dentry *dentry, unsigned int flags)
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{
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if (flags & LOOKUP_RCU)
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return -ECHILD;
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/*
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* This is not negative dentry. Always valid.
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*
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* Note, rename() to existing directory entry will have ->d_inode,
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* and will use existing name which isn't specified name by user.
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*
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* We may be able to drop this positive dentry here. But dropping
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* positive dentry isn't good idea. So it's unsupported like
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* rename("filename", "FILENAME") for now.
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*/
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if (dentry->d_inode)
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return 1;
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/*
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* This may be nfsd (or something), anyway, we can't see the
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* intent of this. So, since this can be for creation, drop it.
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*/
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if (!flags)
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return 0;
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/*
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* Drop the negative dentry, in order to make sure to use the
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* case sensitive name which is specified by user if this is
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* for creation.
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*/
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if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
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return 0;
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return vfat_revalidate_shortname(dentry);
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}
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/* returns the length of a struct qstr, ignoring trailing dots */
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static unsigned int __vfat_striptail_len(unsigned int len, const char *name)
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{
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while (len && name[len - 1] == '.')
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len--;
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return len;
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}
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static unsigned int vfat_striptail_len(const struct qstr *qstr)
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{
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return __vfat_striptail_len(qstr->len, qstr->name);
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}
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/*
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* Compute the hash for the vfat name corresponding to the dentry.
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* Note: if the name is invalid, we leave the hash code unchanged so
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* that the existing dentry can be used. The vfat fs routines will
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* return ENOENT or EINVAL as appropriate.
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*/
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static int vfat_hash(const struct dentry *dentry, struct qstr *qstr)
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{
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qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
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return 0;
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}
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/*
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* Compute the hash for the vfat name corresponding to the dentry.
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* Note: if the name is invalid, we leave the hash code unchanged so
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* that the existing dentry can be used. The vfat fs routines will
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* return ENOENT or EINVAL as appropriate.
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*/
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static int vfat_hashi(const struct dentry *dentry, struct qstr *qstr)
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{
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struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io;
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const unsigned char *name;
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unsigned int len;
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unsigned long hash;
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name = qstr->name;
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len = vfat_striptail_len(qstr);
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hash = init_name_hash();
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while (len--)
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hash = partial_name_hash(nls_tolower(t, *name++), hash);
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qstr->hash = end_name_hash(hash);
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return 0;
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}
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/*
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* Case insensitive compare of two vfat names.
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*/
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static int vfat_cmpi(const struct dentry *parent, const struct dentry *dentry,
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unsigned int len, const char *str, const struct qstr *name)
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{
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struct nls_table *t = MSDOS_SB(parent->d_sb)->nls_io;
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unsigned int alen, blen;
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/* A filename cannot end in '.' or we treat it like it has none */
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alen = vfat_striptail_len(name);
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blen = __vfat_striptail_len(len, str);
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if (alen == blen) {
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if (nls_strnicmp(t, name->name, str, alen) == 0)
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return 0;
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}
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return 1;
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}
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/*
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* Case sensitive compare of two vfat names.
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*/
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static int vfat_cmp(const struct dentry *parent, const struct dentry *dentry,
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unsigned int len, const char *str, const struct qstr *name)
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{
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unsigned int alen, blen;
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/* A filename cannot end in '.' or we treat it like it has none */
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alen = vfat_striptail_len(name);
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blen = __vfat_striptail_len(len, str);
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if (alen == blen) {
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if (strncmp(name->name, str, alen) == 0)
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return 0;
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}
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return 1;
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}
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static const struct dentry_operations vfat_ci_dentry_ops = {
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.d_revalidate = vfat_revalidate_ci,
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.d_hash = vfat_hashi,
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.d_compare = vfat_cmpi,
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};
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static const struct dentry_operations vfat_dentry_ops = {
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.d_revalidate = vfat_revalidate,
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.d_hash = vfat_hash,
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.d_compare = vfat_cmp,
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};
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/* Characters that are undesirable in an MS-DOS file name */
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static inline wchar_t vfat_bad_char(wchar_t w)
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{
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return (w < 0x0020)
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|| (w == '*') || (w == '?') || (w == '<') || (w == '>')
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|| (w == '|') || (w == '"') || (w == ':') || (w == '/')
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|| (w == '\\');
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}
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static inline wchar_t vfat_replace_char(wchar_t w)
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{
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return (w == '[') || (w == ']') || (w == ';') || (w == ',')
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|| (w == '+') || (w == '=');
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}
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static wchar_t vfat_skip_char(wchar_t w)
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{
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return (w == '.') || (w == ' ');
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}
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static inline int vfat_is_used_badchars(const wchar_t *s, int len)
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{
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int i;
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for (i = 0; i < len; i++)
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if (vfat_bad_char(s[i]))
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return -EINVAL;
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if (s[i - 1] == ' ') /* last character cannot be space */
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return -EINVAL;
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return 0;
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}
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static int vfat_find_form(struct inode *dir, unsigned char *name)
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{
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struct fat_slot_info sinfo;
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int err = fat_scan(dir, name, &sinfo);
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if (err)
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return -ENOENT;
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brelse(sinfo.bh);
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return 0;
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}
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/*
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* 1) Valid characters for the 8.3 format alias are any combination of
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* letters, uppercase alphabets, digits, any of the
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* following special characters:
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* $ % ' ` - @ { } ~ ! # ( ) & _ ^
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* In this case Longfilename is not stored in disk.
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*
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* WinNT's Extension:
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* File name and extension name is contain uppercase/lowercase
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* only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT.
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*
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* 2) File name is 8.3 format, but it contain the uppercase and
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* lowercase char, muliti bytes char, etc. In this case numtail is not
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* added, but Longfilename is stored.
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*
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* 3) When the one except for the above, or the following special
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* character are contained:
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* . [ ] ; , + =
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* numtail is added, and Longfilename must be stored in disk .
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*/
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struct shortname_info {
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unsigned char lower:1,
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upper:1,
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valid:1;
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};
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#define INIT_SHORTNAME_INFO(x) do { \
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(x)->lower = 1; \
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(x)->upper = 1; \
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(x)->valid = 1; \
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} while (0)
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static inline int to_shortname_char(struct nls_table *nls,
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unsigned char *buf, int buf_size,
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wchar_t *src, struct shortname_info *info)
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{
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int len;
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if (vfat_skip_char(*src)) {
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info->valid = 0;
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return 0;
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}
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if (vfat_replace_char(*src)) {
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info->valid = 0;
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buf[0] = '_';
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return 1;
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}
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len = nls->uni2char(*src, buf, buf_size);
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if (len <= 0) {
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info->valid = 0;
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buf[0] = '_';
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len = 1;
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} else if (len == 1) {
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unsigned char prev = buf[0];
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if (buf[0] >= 0x7F) {
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info->lower = 0;
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info->upper = 0;
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}
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buf[0] = nls_toupper(nls, buf[0]);
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if (isalpha(buf[0])) {
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if (buf[0] == prev)
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info->lower = 0;
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else
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info->upper = 0;
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}
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} else {
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info->lower = 0;
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info->upper = 0;
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}
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return len;
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}
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/*
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* Given a valid longname, create a unique shortname. Make sure the
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* shortname does not exist
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* Returns negative number on error, 0 for a normal
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* return, and 1 for valid shortname
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*/
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static int vfat_create_shortname(struct inode *dir, struct nls_table *nls,
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wchar_t *uname, int ulen,
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unsigned char *name_res, unsigned char *lcase)
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{
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struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options;
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wchar_t *ip, *ext_start, *end, *name_start;
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unsigned char base[9], ext[4], buf[5], *p;
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unsigned char charbuf[NLS_MAX_CHARSET_SIZE];
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int chl, chi;
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int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen;
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int is_shortname;
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struct shortname_info base_info, ext_info;
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is_shortname = 1;
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INIT_SHORTNAME_INFO(&base_info);
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INIT_SHORTNAME_INFO(&ext_info);
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/* Now, we need to create a shortname from the long name */
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ext_start = end = &uname[ulen];
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while (--ext_start >= uname) {
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if (*ext_start == 0x002E) { /* is `.' */
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if (ext_start == end - 1) {
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sz = ulen;
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ext_start = NULL;
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}
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break;
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}
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}
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if (ext_start == uname - 1) {
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sz = ulen;
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ext_start = NULL;
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} else if (ext_start) {
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/*
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* Names which start with a dot could be just
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* an extension eg. "...test". In this case Win95
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* uses the extension as the name and sets no extension.
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*/
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name_start = &uname[0];
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while (name_start < ext_start) {
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if (!vfat_skip_char(*name_start))
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break;
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name_start++;
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}
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if (name_start != ext_start) {
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sz = ext_start - uname;
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ext_start++;
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} else {
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sz = ulen;
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ext_start = NULL;
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}
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}
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numtail_baselen = 6;
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numtail2_baselen = 2;
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for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) {
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chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
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ip, &base_info);
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if (chl == 0)
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continue;
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if (baselen < 2 && (baselen + chl) > 2)
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numtail2_baselen = baselen;
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if (baselen < 6 && (baselen + chl) > 6)
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numtail_baselen = baselen;
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for (chi = 0; chi < chl; chi++) {
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*p++ = charbuf[chi];
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baselen++;
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if (baselen >= 8)
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break;
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}
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if (baselen >= 8) {
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if ((chi < chl - 1) || (ip + 1) - uname < sz)
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is_shortname = 0;
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break;
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}
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}
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if (baselen == 0) {
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return -EINVAL;
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}
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extlen = 0;
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if (ext_start) {
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for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) {
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chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
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ip, &ext_info);
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if (chl == 0)
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continue;
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if ((extlen + chl) > 3) {
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is_shortname = 0;
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break;
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}
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for (chi = 0; chi < chl; chi++) {
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*p++ = charbuf[chi];
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extlen++;
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}
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if (extlen >= 3) {
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if (ip + 1 != end)
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is_shortname = 0;
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break;
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}
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}
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}
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ext[extlen] = '\0';
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base[baselen] = '\0';
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/* Yes, it can happen. ".\xe5" would do it. */
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if (base[0] == DELETED_FLAG)
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base[0] = 0x05;
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|
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/* OK, at this point we know that base is not longer than 8 symbols,
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* ext is not longer than 3, base is nonempty, both don't contain
|
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* any bad symbols (lowercase transformed to uppercase).
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*/
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memset(name_res, ' ', MSDOS_NAME);
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memcpy(name_res, base, baselen);
|
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memcpy(name_res + 8, ext, extlen);
|
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*lcase = 0;
|
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if (is_shortname && base_info.valid && ext_info.valid) {
|
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if (vfat_find_form(dir, name_res) == 0)
|
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return -EEXIST;
|
|
|
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if (opts->shortname & VFAT_SFN_CREATE_WIN95) {
|
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return (base_info.upper && ext_info.upper);
|
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} else if (opts->shortname & VFAT_SFN_CREATE_WINNT) {
|
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if ((base_info.upper || base_info.lower) &&
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(ext_info.upper || ext_info.lower)) {
|
|
if (!base_info.upper && base_info.lower)
|
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*lcase |= CASE_LOWER_BASE;
|
|
if (!ext_info.upper && ext_info.lower)
|
|
*lcase |= CASE_LOWER_EXT;
|
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return 1;
|
|
}
|
|
return 0;
|
|
} else {
|
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BUG();
|
|
}
|
|
}
|
|
|
|
if (opts->numtail == 0)
|
|
if (vfat_find_form(dir, name_res) < 0)
|
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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 nc;
|
|
unsigned char *op;
|
|
unsigned int ec;
|
|
int i, k, 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 == ':')) {
|
|
if (i > len - 5)
|
|
return -EINVAL;
|
|
ec = 0;
|
|
for (k = 1; k < 5; k++) {
|
|
nc = ip[k];
|
|
ec <<= 4;
|
|
if (nc >= '0' && nc <= '9') {
|
|
ec |= nc - '0';
|
|
continue;
|
|
}
|
|
if (nc >= 'a' && nc <= 'f') {
|
|
ec |= nc - ('a' - 10);
|
|
continue;
|
|
}
|
|
if (nc >= 'A' && nc <= 'F') {
|
|
ec |= nc - ('A' - 10);
|
|
continue;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
*op++ = ec & 0xFF;
|
|
*op++ = ec >> 8;
|
|
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, 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(sizeof(*slots) * MSDOS_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 = *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, 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);
|
|
}
|
|
|
|
/*
|
|
* (nfsd's) anonymous disconnected dentry?
|
|
* NOTE: !IS_ROOT() is not anonymous (I.e. d_splice_alias() did the job).
|
|
*/
|
|
static int vfat_d_anon_disconn(struct dentry *dentry)
|
|
{
|
|
return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED);
|
|
}
|
|
|
|
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);
|
|
if (alias && !vfat_d_anon_disconn(alias)) {
|
|
/*
|
|
* 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.
|
|
*/
|
|
BUG_ON(d_unhashed(alias));
|
|
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);
|
|
dentry->d_time = dentry->d_parent->d_inode->i_version;
|
|
dentry = d_splice_alias(inode, dentry);
|
|
if (dentry)
|
|
dentry->d_time = dentry->d_parent->d_inode->i_version;
|
|
return 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 timespec ts;
|
|
int err;
|
|
|
|
mutex_lock(&MSDOS_SB(sb)->s_lock);
|
|
|
|
ts = CURRENT_TIME_SEC;
|
|
err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo);
|
|
if (err)
|
|
goto out;
|
|
dir->i_version++;
|
|
|
|
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
|
|
brelse(sinfo.bh);
|
|
if (IS_ERR(inode)) {
|
|
err = PTR_ERR(inode);
|
|
goto out;
|
|
}
|
|
inode->i_version++;
|
|
inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
|
|
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
|
|
|
|
dentry->d_time = dentry->d_parent->d_inode->i_version;
|
|
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 = dentry->d_inode;
|
|
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_SEC;
|
|
fat_detach(inode);
|
|
out:
|
|
mutex_unlock(&MSDOS_SB(sb)->s_lock);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int vfat_unlink(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct inode *inode = dentry->d_inode;
|
|
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_SEC;
|
|
fat_detach(inode);
|
|
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 timespec ts;
|
|
int err, cluster;
|
|
|
|
mutex_lock(&MSDOS_SB(sb)->s_lock);
|
|
|
|
ts = CURRENT_TIME_SEC;
|
|
cluster = fat_alloc_new_dir(dir, &ts);
|
|
if (cluster < 0) {
|
|
err = cluster;
|
|
goto out;
|
|
}
|
|
err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo);
|
|
if (err)
|
|
goto out_free;
|
|
dir->i_version++;
|
|
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->i_version++;
|
|
set_nlink(inode, 2);
|
|
inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
|
|
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
|
|
|
|
dentry->d_time = dentry->d_parent->d_inode->i_version;
|
|
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)
|
|
{
|
|
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 timespec ts;
|
|
loff_t new_i_pos;
|
|
int err, is_dir, update_dotdot, corrupt = 0;
|
|
struct super_block *sb = old_dir->i_sb;
|
|
|
|
old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
|
|
old_inode = old_dentry->d_inode;
|
|
new_inode = new_dentry->d_inode;
|
|
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_SEC;
|
|
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 {
|
|
err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0,
|
|
&ts, &sinfo);
|
|
if (err)
|
|
goto out;
|
|
new_i_pos = sinfo.i_pos;
|
|
}
|
|
new_dir->i_version++;
|
|
|
|
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;
|
|
old_dir->i_version++;
|
|
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)
|