Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

2 files changed, 1089 insertions, 0 deletions

diff --git a/fs/vfat/Makefile b/fs/vfat/Makefile
new file mode 100644
index 0000000..40f2798
--- /dev/null
+++ b/fs/vfat/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for the linux vfat-filesystem routines.
+#
+
+obj-$(CONFIG_VFAT_FS) += vfat.o
+
+vfat-y := namei.o
diff --git a/fs/vfat/namei.c b/fs/vfat/namei.c
new file mode 100644
index 0000000..1c6f6b5
--- /dev/null
+++ b/fs/vfat/namei.c
@@ -0,0 +1,1082 @@
+/*
+ *  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/jiffies.h>
+#include <linux/msdos_fs.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+#include <linux/namei.h>
+
+static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	int ret = 1;
+
+	if (!dentry->d_inode &&
+	    nd && !(nd->flags & LOOKUP_CONTINUE) && (nd->flags & LOOKUP_CREATE))
+		/*
+		 * negative dentry is dropped, in order to make sure
+		 * to use the name which a user desires if this is
+		 * create path.
+		 */
+		ret = 0;
+	else {
+		spin_lock(&dentry->d_lock);
+		if (dentry->d_time != dentry->d_parent->d_inode->i_version)
+			ret = 0;
+		spin_unlock(&dentry->d_lock);
+	}
+	return ret;
+}
+
+/* returns the length of a struct qstr, ignoring trailing dots */
+static unsigned int vfat_striptail_len(struct qstr *qstr)
+{
+	unsigned int len = qstr->len;
+
+	while (len && qstr->name[len - 1] == '.')
+		len--;
+	return len;
+}
+
+/*
+ * 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(struct dentry *dentry, struct qstr *qstr)
+{
+	qstr->hash = full_name_hash(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(struct dentry *dentry, struct qstr *qstr)
+{
+	struct nls_table *t = MSDOS_SB(dentry->d_inode->i_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();
+	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(struct dentry *dentry, struct qstr *a, struct qstr *b)
+{
+	struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
+	unsigned int alen, blen;
+
+	/* A filename cannot end in '.' or we treat it like it has none */
+	alen = vfat_striptail_len(a);
+	blen = vfat_striptail_len(b);
+	if (alen == blen) {
+		if (nls_strnicmp(t, a->name, b->name, alen) == 0)
+			return 0;
+	}
+	return 1;
+}
+
+/*
+ * Case sensitive compare of two vfat names.
+ */
+static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
+{
+	unsigned int alen, blen;
+
+	/* A filename cannot end in '.' or we treat it like it has none */
+	alen = vfat_striptail_len(a);
+	blen = vfat_striptail_len(b);
+	if (alen == blen) {
+		if (strncmp(a->name, b->name, alen) == 0)
+			return 0;
+	}
+	return 1;
+}
+
+static struct dentry_operations vfat_dentry_ops[4] = {
+	{
+		.d_hash		= vfat_hashi,
+		.d_compare	= vfat_cmpi,
+	},
+	{
+		.d_revalidate	= vfat_revalidate,
+		.d_hash		= vfat_hashi,
+		.d_compare	= vfat_cmpi,
+	},
+	{
+		.d_hash		= vfat_hash,
+		.d_compare	= vfat_cmp,
+	},
+	{
+		.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;
+	return 0;
+}
+
+static int vfat_valid_longname(const unsigned char *name, unsigned int len)
+{
+	if (name[len - 1] == ' ')
+		return -EINVAL;
+	if (len >= 256)
+		return -ENAMETOOLONG;
+
+	/* MS-DOS "device special files" */
+	if (len == 3 || (len > 3 && name[3] == '.')) {	/* basename == 3 */
+		if (!strnicmp(name, "aux", 3) ||
+		    !strnicmp(name, "con", 3) ||
+		    !strnicmp(name, "nul", 3) ||
+		    !strnicmp(name, "prn", 3))
+			return -EINVAL;
+	}
+	if (len == 4 || (len > 4 && name[4] == '.')) {	/* basename == 4 */
+		/* "com1", "com2", ... */
+		if ('1' <= name[3] && name[3] <= '9') {
+			if (!strnicmp(name, "com", 3) ||
+			    !strnicmp(name, "lpt", 3))
+				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[8], *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 & 0xffff;
+	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) {
+		sprintf(buf, "%04X", i);
+		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) {
+		int name_len = strlen(name);
+
+		*outlen = utf8_mbstowcs((wchar_t *)outname, name, PAGE_SIZE);
+
+		/*
+		 * We stripped '.'s before and set len appropriately,
+		 * but utf8_mbstowcs doesn't care about len
+		 */
+		*outlen -= (name_len - len);
+
+		op = &outname[*outlen * sizeof(wchar_t)];
+	} else {
+		if (nls) {
+			for (i = 0, ip = name, op = outname, *outlen = 0;
+			     i < len && *outlen <= 260;
+			     *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 {
+					if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0)
+						return -EINVAL;
+					ip += charlen;
+					i += charlen;
+					op += 2;
+				}
+			}
+		} else {
+			for (i = 0, ip = name, op = outname, *outlen = 0;
+			     i < len && *outlen <= 260;
+			     i++, *outlen += 1)
+			{
+				*op++ = *ip++;
+				*op++ = 0;
+			}
+		}
+	}
+	if (*outlen > 260)
+		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 long page;
+	unsigned char cksum, lcase;
+	unsigned char msdos_name[MSDOS_NAME];
+	wchar_t *uname;
+	__le16 time, date;
+	int err, ulen, usize, i;
+	loff_t offset;
+
+	*nr_slots = 0;
+	err = vfat_valid_longname(name, len);
+	if (err)
+		return err;
+
+	page = __get_free_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+
+	uname = (wchar_t *)page;
+	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 */
+	for (cksum = i = 0; i < 11; i++)
+		cksum = (((cksum&1)<<7)|((cksum&0xfe)>>1)) + msdos_name[i];
+
+	*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_date_unix2dos(ts->tv_sec, &time, &date);
+	de->time = de->ctime = time;
+	de->date = de->cdate = de->adate = date;
+	de->ctime_cs = 0;
+	de->start = cpu_to_le16(cluster);
+	de->starthi = cpu_to_le16(cluster >> 16);
+	de->size = 0;
+out_free:
+	free_page(page);
+	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_KERNEL);
+	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);
+}
+
+static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
+				  struct nameidata *nd)
+{
+	struct super_block *sb = dir->i_sb;
+	struct fat_slot_info sinfo;
+	struct inode *inode = NULL;
+	struct dentry *alias;
+	int err, table;
+
+	lock_kernel();
+	table = (MSDOS_SB(sb)->options.name_check == 's') ? 2 : 0;
+	dentry->d_op = &vfat_dentry_ops[table];
+
+	err = vfat_find(dir, &dentry->d_name, &sinfo);
+	if (err) {
+		table++;
+		goto error;
+	}
+	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
+	brelse(sinfo.bh);
+	if (IS_ERR(inode)) {
+		unlock_kernel();
+		return ERR_PTR(PTR_ERR(inode));
+	}
+	alias = d_find_alias(inode);
+	if (alias) {
+		if (d_invalidate(alias) == 0)
+			dput(alias);
+		else {
+			iput(inode);
+			unlock_kernel();
+			return alias;
+		}
+
+	}
+error:
+	unlock_kernel();
+	dentry->d_op = &vfat_dentry_ops[table];
+	dentry->d_time = dentry->d_parent->d_inode->i_version;
+	dentry = d_splice_alias(inode, dentry);
+	if (dentry) {
+		dentry->d_op = &vfat_dentry_ops[table];
+		dentry->d_time = dentry->d_parent->d_inode->i_version;
+	}
+	return dentry;
+}
+
+static int vfat_create(struct inode *dir, struct dentry *dentry, int mode,
+		       struct nameidata *nd)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode;
+	struct fat_slot_info sinfo;
+	struct timespec ts;
+	int err;
+
+	lock_kernel();
+
+	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:
+	unlock_kernel();
+	return err;
+}
+
+static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct fat_slot_info sinfo;
+	int err;
+
+	lock_kernel();
+
+	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;
+	dir->i_nlink--;
+
+	inode->i_nlink = 0;
+	inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
+	fat_detach(inode);
+out:
+	unlock_kernel();
+
+	return err;
+}
+
+static int vfat_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct fat_slot_info sinfo;
+	int err;
+
+	lock_kernel();
+
+	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;
+	inode->i_nlink = 0;
+	inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
+	fat_detach(inode);
+out:
+	unlock_kernel();
+
+	return err;
+}
+
+static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode;
+	struct fat_slot_info sinfo;
+	struct timespec ts;
+	int err, cluster;
+
+	lock_kernel();
+
+	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++;
+	dir->i_nlink++;
+
+	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++;
+	inode->i_nlink = 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);
+
+	unlock_kernel();
+	return 0;
+
+out_free:
+	fat_free_clusters(dir, cluster);
+out:
+	unlock_kernel();
+	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;
+	loff_t dotdot_i_pos;
+	struct inode *old_inode, *new_inode;
+	struct fat_slot_info old_sinfo, sinfo;
+	struct timespec ts;
+	int err, is_dir, update_dotdot, corrupt = 0;
+
+	old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
+	old_inode = old_dentry->d_inode;
+	new_inode = new_dentry->d_inode;
+	lock_kernel();
+	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,
+					 &dotdot_i_pos) < 0) {
+			err = -EIO;
+			goto out;
+		}
+	}
+
+	ts = CURRENT_TIME_SEC;
+	if (new_inode) {
+		err = vfat_find(new_dir, &new_dentry->d_name, &sinfo);
+		if (err)
+			goto out;
+		if (MSDOS_I(new_inode)->i_pos != sinfo.i_pos) {
+			/* WTF??? Cry and fail. */
+			printk(KERN_WARNING "vfat_rename: fs corrupted\n");
+			goto out;
+		}
+
+		if (is_dir) {
+			err = fat_dir_empty(new_inode);
+			if (err)
+				goto out;
+		}
+		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_dir->i_version++;
+
+	fat_detach(old_inode);
+	fat_attach(old_inode, sinfo.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) {
+		int start = MSDOS_I(new_dir)->i_logstart;
+		dotdot_de->start = cpu_to_le16(start);
+		dotdot_de->starthi = cpu_to_le16(start >> 16);
+		mark_buffer_dirty(dotdot_bh);
+		if (IS_DIRSYNC(new_dir)) {
+			err = sync_dirty_buffer(dotdot_bh);
+			if (err)
+				goto error_dotdot;
+		}
+		old_dir->i_nlink--;
+		if (!new_inode)
+ 			new_dir->i_nlink++;
+	}
+
+	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) {
+		if (is_dir)
+			new_inode->i_nlink -= 2;
+		else
+			new_inode->i_nlink--;
+		new_inode->i_ctime = ts;
+	}
+out:
+	brelse(sinfo.bh);
+	brelse(dotdot_bh);
+	brelse(old_sinfo.bh);
+	unlock_kernel();
+
+	return err;
+
+error_dotdot:
+	/* data cluster is shared, serious corruption */
+	corrupt = 1;
+
+	if (update_dotdot) {
+		int start = MSDOS_I(old_dir)->i_logstart;
+		dotdot_de->start = cpu_to_le16(start);
+		dotdot_de->starthi = cpu_to_le16(start >> 16);
+		mark_buffer_dirty(dotdot_bh);
+		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, sinfo.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_panic(new_dir->i_sb,
+			     "%s: Filesystem corrupted (i_pos %lld)",
+			     __FUNCTION__, sinfo.i_pos);
+	}
+	goto out;
+}
+
+static 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_notify_change,
+};
+
+static int vfat_fill_super(struct super_block *sb, void *data, int silent)
+{
+	int res;
+
+	res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1);
+	if (res)
+		return res;
+
+	if (MSDOS_SB(sb)->options.name_check != 's')
+		sb->s_root->d_op = &vfat_dentry_ops[0];
+	else
+		sb->s_root->d_op = &vfat_dentry_ops[2];
+
+	return 0;
+}
+
+static struct super_block *vfat_get_sb(struct file_system_type *fs_type,
+				       int flags, const char *dev_name,
+				       void *data)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super);
+}
+
+static struct file_system_type vfat_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "vfat",
+	.get_sb		= vfat_get_sb,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+
+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)