Merge commit 'v2.6.28-rc8' into x86/doc

10 files changed, 2396 insertions, 149 deletions

diff --git a/fs/fat/Makefile b/fs/fat/Makefile
index bfb5f06cf2c..e06190322c1 100644
--- a/fs/fat/Makefile
+++ b/fs/fat/Makefile
@@ -3,5 +3,9 @@
 #
 
 obj-$(CONFIG_FAT_FS) += fat.o
+obj-$(CONFIG_VFAT_FS) += vfat.o
+obj-$(CONFIG_MSDOS_FS) += msdos.o
 
-fat-objs := cache.o dir.o fatent.o file.o inode.o misc.o
+fat-y := cache.o dir.o fatent.o file.o inode.o misc.o
+vfat-y := namei_vfat.o
+msdos-y := namei_msdos.o
diff --git a/fs/fat/cache.c b/fs/fat/cache.c
index 3222f51c41c..b4260229808 100644
--- a/fs/fat/cache.c
+++ b/fs/fat/cache.c
@@ -9,8 +9,8 @@
  */
 
 #include <linux/fs.h>
-#include <linux/msdos_fs.h>
 #include <linux/buffer_head.h>
+#include "fat.h"
 
 /* this must be > 0. */
 #define FAT_MAX_CACHE	8
@@ -293,10 +293,12 @@ static int fat_bmap_cluster(struct inode *inode, int cluster)
 }
 
 int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
-	     unsigned long *mapped_blocks)
+	     unsigned long *mapped_blocks, int create)
 {
 	struct super_block *sb = inode->i_sb;
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	const unsigned long blocksize = sb->s_blocksize;
+	const unsigned char blocksize_bits = sb->s_blocksize_bits;
 	sector_t last_block;
 	int cluster, offset;
 
@@ -309,10 +311,21 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
 		}
 		return 0;
 	}
-	last_block = (MSDOS_I(inode)->mmu_private + (sb->s_blocksize - 1))
-		>> sb->s_blocksize_bits;
-	if (sector >= last_block)
-		return 0;
+
+	last_block = (i_size_read(inode) + (blocksize - 1)) >> blocksize_bits;
+	if (sector >= last_block) {
+		if (!create)
+			return 0;
+
+		/*
+		 * ->mmu_private can access on only allocation path.
+		 * (caller must hold ->i_mutex)
+		 */
+		last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1))
+			>> blocksize_bits;
+		if (sector >= last_block)
+			return 0;
+	}
 
 	cluster = sector >> (sbi->cluster_bits - sb->s_blocksize_bits);
 	offset  = sector & (sbi->sec_per_clus - 1);
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index bae1c329252..67e05835709 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -16,11 +16,11 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/time.h>
-#include <linux/msdos_fs.h>
 #include <linux/smp_lock.h>
 #include <linux/buffer_head.h>
 #include <linux/compat.h>
 #include <asm/uaccess.h>
+#include "fat.h"
 
 static inline loff_t fat_make_i_pos(struct super_block *sb,
 				    struct buffer_head *bh,
@@ -77,7 +77,7 @@ next:
 
 	*bh = NULL;
 	iblock = *pos >> sb->s_blocksize_bits;
-	err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
+	err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0);
 	if (err || !phys)
 		return -1;	/* beyond EOF or error */
 
@@ -86,7 +86,7 @@ next:
 	*bh = sb_bread(sb, phys);
 	if (*bh == NULL) {
 		printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
-		       (unsigned long long)phys);
+		       (llu)phys);
 		/* skip this block */
 		*pos = (iblock + 1) << sb->s_blocksize_bits;
 		goto next;
@@ -373,9 +373,10 @@ parse_record:
 		if (de->attr == ATTR_EXT) {
 			int status = fat_parse_long(inode, &cpos, &bh, &de,
 						    &unicode, &nr_slots);
-			if (status < 0)
-				return status;
-			else if (status == PARSE_INVALID)
+			if (status < 0) {
+				err = status;
+				goto end_of_dir;
+			} else if (status == PARSE_INVALID)
 				continue;
 			else if (status == PARSE_NOT_LONGNAME)
 				goto parse_record;
@@ -832,6 +833,7 @@ static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
 #endif /* CONFIG_COMPAT */
 
 const struct file_operations fat_dir_operations = {
+	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.readdir	= fat_readdir,
 	.ioctl		= fat_dir_ioctl,
@@ -1089,6 +1091,7 @@ int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
 	struct msdos_dir_entry *de;
 	sector_t blknr;
 	__le16 date, time;
+	u8 time_cs;
 	int err, cluster;
 
 	err = fat_alloc_clusters(dir, &cluster, 1);
@@ -1102,7 +1105,7 @@ int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
 		goto error_free;
 	}
 
-	fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
+	fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
 
 	de = (struct msdos_dir_entry *)bhs[0]->b_data;
 	/* filling the new directory slots ("." and ".." entries) */
@@ -1112,13 +1115,14 @@ int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
 	de[0].lcase = de[1].lcase = 0;
 	de[0].time = de[1].time = time;
 	de[0].date = de[1].date = date;
-	de[0].ctime_cs = de[1].ctime_cs = 0;
 	if (sbi->options.isvfat) {
 		/* extra timestamps */
 		de[0].ctime = de[1].ctime = time;
+		de[0].ctime_cs = de[1].ctime_cs = time_cs;
 		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
 	} else {
 		de[0].ctime = de[1].ctime = 0;
+		de[0].ctime_cs = de[1].ctime_cs = 0;
 		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
 	}
 	de[0].start = cpu_to_le16(cluster);
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
new file mode 100644
index 00000000000..ea440d65819
--- /dev/null
+++ b/fs/fat/fat.h
@@ -0,0 +1,329 @@
+#ifndef _FAT_H
+#define _FAT_H
+
+#include <linux/buffer_head.h>
+#include <linux/string.h>
+#include <linux/nls.h>
+#include <linux/fs.h>
+#include <linux/mutex.h>
+#include <linux/msdos_fs.h>
+
+/*
+ * vfat shortname flags
+ */
+#define VFAT_SFN_DISPLAY_LOWER	0x0001 /* convert to lowercase for display */
+#define VFAT_SFN_DISPLAY_WIN95	0x0002 /* emulate win95 rule for display */
+#define VFAT_SFN_DISPLAY_WINNT	0x0004 /* emulate winnt rule for display */
+#define VFAT_SFN_CREATE_WIN95	0x0100 /* emulate win95 rule for create */
+#define VFAT_SFN_CREATE_WINNT	0x0200 /* emulate winnt rule for create */
+
+struct fat_mount_options {
+	uid_t fs_uid;
+	gid_t fs_gid;
+	unsigned short fs_fmask;
+	unsigned short fs_dmask;
+	unsigned short codepage;  /* Codepage for shortname conversions */
+	char *iocharset;          /* Charset used for filename input/display */
+	unsigned short shortname; /* flags for shortname display/create rule */
+	unsigned char name_check; /* r = relaxed, n = normal, s = strict */
+	unsigned short allow_utime;/* permission for setting the [am]time */
+	unsigned quiet:1,         /* set = fake successful chmods and chowns */
+		 showexec:1,      /* set = only set x bit for com/exe/bat */
+		 sys_immutable:1, /* set = system files are immutable */
+		 dotsOK:1,        /* set = hidden and system files are named '.filename' */
+		 isvfat:1,        /* 0=no vfat long filename support, 1=vfat support */
+		 utf8:1,	  /* Use of UTF-8 character set (Default) */
+		 unicode_xlate:1, /* create escape sequences for unhandled Unicode */
+		 numtail:1,       /* Does first alias have a numeric '~1' type tail? */
+		 flush:1,	  /* write things quickly */
+		 nocase:1,	  /* Does this need case conversion? 0=need case conversion*/
+		 usefree:1,	  /* Use free_clusters for FAT32 */
+		 tz_utc:1,	  /* Filesystem timestamps are in UTC */
+		 rodir:1;	  /* allow ATTR_RO for directory */
+};
+
+#define FAT_HASH_BITS	8
+#define FAT_HASH_SIZE	(1UL << FAT_HASH_BITS)
+
+/*
+ * MS-DOS file system in-core superblock data
+ */
+struct msdos_sb_info {
+	unsigned short sec_per_clus; /* sectors/cluster */
+	unsigned short cluster_bits; /* log2(cluster_size) */
+	unsigned int cluster_size;   /* cluster size */
+	unsigned char fats,fat_bits; /* number of FATs, FAT bits (12 or 16) */
+	unsigned short fat_start;
+	unsigned long fat_length;    /* FAT start & length (sec.) */
+	unsigned long dir_start;
+	unsigned short dir_entries;  /* root dir start & entries */
+	unsigned long data_start;    /* first data sector */
+	unsigned long max_cluster;   /* maximum cluster number */
+	unsigned long root_cluster;  /* first cluster of the root directory */
+	unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
+	struct mutex fat_lock;
+	unsigned int prev_free;      /* previously allocated cluster number */
+	unsigned int free_clusters;  /* -1 if undefined */
+	unsigned int free_clus_valid; /* is free_clusters valid? */
+	struct fat_mount_options options;
+	struct nls_table *nls_disk;  /* Codepage used on disk */
+	struct nls_table *nls_io;    /* Charset used for input and display */
+	const void *dir_ops;		     /* Opaque; default directory operations */
+	int dir_per_block;	     /* dir entries per block */
+	int dir_per_block_bits;	     /* log2(dir_per_block) */
+
+	int fatent_shift;
+	struct fatent_operations *fatent_ops;
+
+	spinlock_t inode_hash_lock;
+	struct hlist_head inode_hashtable[FAT_HASH_SIZE];
+};
+
+#define FAT_CACHE_VALID	0	/* special case for valid cache */
+
+/*
+ * MS-DOS file system inode data in memory
+ */
+struct msdos_inode_info {
+	spinlock_t cache_lru_lock;
+	struct list_head cache_lru;
+	int nr_caches;
+	/* for avoiding the race between fat_free() and fat_get_cluster() */
+	unsigned int cache_valid_id;
+
+	/* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
+	loff_t mmu_private;	/* physically allocated size */
+
+	int i_start;		/* first cluster or 0 */
+	int i_logstart;		/* logical first cluster */
+	int i_attrs;		/* unused attribute bits */
+	loff_t i_pos;		/* on-disk position of directory entry or 0 */
+	struct hlist_node i_fat_hash;	/* hash by i_location */
+	struct inode vfs_inode;
+};
+
+struct fat_slot_info {
+	loff_t i_pos;		/* on-disk position of directory entry */
+	loff_t slot_off;	/* offset for slot or de start */
+	int nr_slots;		/* number of slots + 1(de) in filename */
+	struct msdos_dir_entry *de;
+	struct buffer_head *bh;
+};
+
+static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
+{
+	return container_of(inode, struct msdos_inode_info, vfs_inode);
+}
+
+/*
+ * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
+ * save ATTR_RO instead of ->i_mode.
+ *
+ * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
+ * bit, it's just used as flag for app.
+ */
+static inline int fat_mode_can_hold_ro(struct inode *inode)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+	mode_t mask;
+
+	if (S_ISDIR(inode->i_mode)) {
+		if (!sbi->options.rodir)
+			return 0;
+		mask = ~sbi->options.fs_dmask;
+	} else
+		mask = ~sbi->options.fs_fmask;
+
+	if (!(mask & S_IWUGO))
+		return 0;
+	return 1;
+}
+
+/* Convert attribute bits and a mask to the UNIX mode. */
+static inline mode_t fat_make_mode(struct msdos_sb_info *sbi,
+				   u8 attrs, mode_t mode)
+{
+	if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
+		mode &= ~S_IWUGO;
+
+	if (attrs & ATTR_DIR)
+		return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
+	else
+		return (mode & ~sbi->options.fs_fmask) | S_IFREG;
+}
+
+/* Return the FAT attribute byte for this inode */
+static inline u8 fat_make_attrs(struct inode *inode)
+{
+	u8 attrs = MSDOS_I(inode)->i_attrs;
+	if (S_ISDIR(inode->i_mode))
+		attrs |= ATTR_DIR;
+	if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
+		attrs |= ATTR_RO;
+	return attrs;
+}
+
+static inline void fat_save_attrs(struct inode *inode, u8 attrs)
+{
+	if (fat_mode_can_hold_ro(inode))
+		MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
+	else
+		MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
+}
+
+static inline unsigned char fat_checksum(const __u8 *name)
+{
+	unsigned char s = name[0];
+	s = (s<<7) + (s>>1) + name[1];	s = (s<<7) + (s>>1) + name[2];
+	s = (s<<7) + (s>>1) + name[3];	s = (s<<7) + (s>>1) + name[4];
+	s = (s<<7) + (s>>1) + name[5];	s = (s<<7) + (s>>1) + name[6];
+	s = (s<<7) + (s>>1) + name[7];	s = (s<<7) + (s>>1) + name[8];
+	s = (s<<7) + (s>>1) + name[9];	s = (s<<7) + (s>>1) + name[10];
+	return s;
+}
+
+static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
+{
+	return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
+		+ sbi->data_start;
+}
+
+static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
+{
+#ifdef __BIG_ENDIAN
+	while (len--) {
+		*dst++ = src[0] | (src[1] << 8);
+		src += 2;
+	}
+#else
+	memcpy(dst, src, len * 2);
+#endif
+}
+
+static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
+{
+#ifdef __BIG_ENDIAN
+	while (len--) {
+		dst[0] = *src & 0x00FF;
+		dst[1] = (*src & 0xFF00) >> 8;
+		dst += 2;
+		src++;
+	}
+#else
+	memcpy(dst, src, len * 2);
+#endif
+}
+
+/* fat/cache.c */
+extern void fat_cache_inval_inode(struct inode *inode);
+extern int fat_get_cluster(struct inode *inode, int cluster,
+			   int *fclus, int *dclus);
+extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
+		    unsigned long *mapped_blocks, int create);
+
+/* fat/dir.c */
+extern const struct file_operations fat_dir_operations;
+extern int fat_search_long(struct inode *inode, const unsigned char *name,
+			   int name_len, struct fat_slot_info *sinfo);
+extern int fat_dir_empty(struct inode *dir);
+extern int fat_subdirs(struct inode *dir);
+extern int fat_scan(struct inode *dir, const unsigned char *name,
+		    struct fat_slot_info *sinfo);
+extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
+				struct msdos_dir_entry **de, loff_t *i_pos);
+extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
+extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
+			   struct fat_slot_info *sinfo);
+extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
+
+/* fat/fatent.c */
+struct fat_entry {
+	int entry;
+	union {
+		u8 *ent12_p[2];
+		__le16 *ent16_p;
+		__le32 *ent32_p;
+	} u;
+	int nr_bhs;
+	struct buffer_head *bhs[2];
+};
+
+static inline void fatent_init(struct fat_entry *fatent)
+{
+	fatent->nr_bhs = 0;
+	fatent->entry = 0;
+	fatent->u.ent32_p = NULL;
+	fatent->bhs[0] = fatent->bhs[1] = NULL;
+}
+
+static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
+{
+	fatent->entry = entry;
+	fatent->u.ent32_p = NULL;
+}
+
+static inline void fatent_brelse(struct fat_entry *fatent)
+{
+	int i;
+	fatent->u.ent32_p = NULL;
+	for (i = 0; i < fatent->nr_bhs; i++)
+		brelse(fatent->bhs[i]);
+	fatent->nr_bhs = 0;
+	fatent->bhs[0] = fatent->bhs[1] = NULL;
+}
+
+extern void fat_ent_access_init(struct super_block *sb);
+extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
+			int entry);
+extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
+			 int new, int wait);
+extern int fat_alloc_clusters(struct inode *inode, int *cluster,
+			      int nr_cluster);
+extern int fat_free_clusters(struct inode *inode, int cluster);
+extern int fat_count_free_clusters(struct super_block *sb);
+
+/* fat/file.c */
+extern int fat_generic_ioctl(struct inode *inode, struct file *filp,
+			     unsigned int cmd, unsigned long arg);
+extern const struct file_operations fat_file_operations;
+extern const struct inode_operations fat_file_inode_operations;
+extern int fat_setattr(struct dentry * dentry, struct iattr * attr);
+extern void fat_truncate(struct inode *inode);
+extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
+		       struct kstat *stat);
+
+/* fat/inode.c */
+extern void fat_attach(struct inode *inode, loff_t i_pos);
+extern void fat_detach(struct inode *inode);
+extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
+extern struct inode *fat_build_inode(struct super_block *sb,
+			struct msdos_dir_entry *de, loff_t i_pos);
+extern int fat_sync_inode(struct inode *inode);
+extern int fat_fill_super(struct super_block *sb, void *data, int silent,
+			const struct inode_operations *fs_dir_inode_ops, int isvfat);
+
+extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
+		            struct inode *i2);
+/* fat/misc.c */
+extern void fat_fs_panic(struct super_block *s, const char *fmt, ...)
+	__attribute__ ((format (printf, 2, 3))) __cold;
+extern void fat_clusters_flush(struct super_block *sb);
+extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
+extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
+			      __le16 __time, __le16 __date, u8 time_cs);
+extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
+			      __le16 *time, __le16 *date, u8 *time_cs);
+extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
+
+int fat_cache_init(void);
+void fat_cache_destroy(void);
+
+/* helper for printk */
+typedef unsigned long long	llu;
+
+#endif /* !_FAT_H */
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index fb98b3d847e..da6eea47872 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -7,6 +7,7 @@
 #include <linux/fs.h>
 #include <linux/msdos_fs.h>
 #include <linux/blkdev.h>
+#include "fat.h"
 
 struct fatent_operations {
 	void (*ent_blocknr)(struct super_block *, int, int *, sector_t *);
@@ -92,8 +93,7 @@ static int fat12_ent_bread(struct super_block *sb, struct fat_entry *fatent,
 err_brelse:
 	brelse(bhs[0]);
 err:
-	printk(KERN_ERR "FAT: FAT read failed (blocknr %llu)\n",
-	       (unsigned long long)blocknr);
+	printk(KERN_ERR "FAT: FAT read failed (blocknr %llu)\n", (llu)blocknr);
 	return -EIO;
 }
 
@@ -106,7 +106,7 @@ static int fat_ent_bread(struct super_block *sb, struct fat_entry *fatent,
 	fatent->bhs[0] = sb_bread(sb, blocknr);
 	if (!fatent->bhs[0]) {
 		printk(KERN_ERR "FAT: FAT read failed (blocknr %llu)\n",
-		       (unsigned long long)blocknr);
+		       (llu)blocknr);
 		return -EIO;
 	}
 	fatent->nr_bhs = 1;
@@ -316,10 +316,20 @@ static inline int fat_ent_update_ptr(struct super_block *sb,
 	/* Is this fatent's blocks including this entry? */
 	if (!fatent->nr_bhs || bhs[0]->b_blocknr != blocknr)
 		return 0;
-	/* Does this entry need the next block? */
-	if (sbi->fat_bits == 12 && (offset + 1) >= sb->s_blocksize) {
-		if (fatent->nr_bhs != 2 || bhs[1]->b_blocknr != (blocknr + 1))
-			return 0;
+	if (sbi->fat_bits == 12) {
+		if ((offset + 1) < sb->s_blocksize) {
+			/* This entry is on bhs[0]. */
+			if (fatent->nr_bhs == 2) {
+				brelse(bhs[1]);
+				fatent->nr_bhs = 1;
+			}
+		} else {
+			/* This entry needs the next block. */
+			if (fatent->nr_bhs != 2)
+				return 0;
+			if (bhs[1]->b_blocknr != (blocknr + 1))
+				return 0;
+		}
 	}
 	ops->ent_set_ptr(fatent, offset);
 	return 1;
diff --git a/fs/fat/file.c b/fs/fat/file.c
index ddde37025ca..f06a4e525ec 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -10,13 +10,13 @@
 #include <linux/module.h>
 #include <linux/mount.h>
 #include <linux/time.h>
-#include <linux/msdos_fs.h>
 #include <linux/buffer_head.h>
 #include <linux/writeback.h>
 #include <linux/backing-dev.h>
 #include <linux/blkdev.h>
 #include <linux/fsnotify.h>
 #include <linux/security.h>
+#include "fat.h"
 
 int fat_generic_ioctl(struct inode *inode, struct file *filp,
 		      unsigned int cmd, unsigned long arg)
@@ -29,10 +29,9 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
 	{
 		u32 attr;
 
-		if (inode->i_ino == MSDOS_ROOT_INO)
-			attr = ATTR_DIR;
-		else
-			attr = fat_attr(inode);
+		mutex_lock(&inode->i_mutex);
+		attr = fat_make_attrs(inode);
+		mutex_unlock(&inode->i_mutex);
 
 		return put_user(attr, user_attr);
 	}
@@ -62,20 +61,16 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
 		/* Merge in ATTR_VOLUME and ATTR_DIR */
 		attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) |
 			(is_dir ? ATTR_DIR : 0);
-		oldattr = fat_attr(inode);
+		oldattr = fat_make_attrs(inode);
 
 		/* Equivalent to a chmod() */
 		ia.ia_valid = ATTR_MODE | ATTR_CTIME;
 		ia.ia_ctime = current_fs_time(inode->i_sb);
-		if (is_dir) {
-			ia.ia_mode = MSDOS_MKMODE(attr,
-				S_IRWXUGO & ~sbi->options.fs_dmask)
-				| S_IFDIR;
-		} else {
-			ia.ia_mode = MSDOS_MKMODE(attr,
-				(S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO))
-				& ~sbi->options.fs_fmask)
-				| S_IFREG;
+		if (is_dir)
+			ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
+		else {
+			ia.ia_mode = fat_make_mode(sbi, attr,
+				S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO));
 		}
 
 		/* The root directory has no attributes */
@@ -115,7 +110,7 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
 				inode->i_flags &= S_IMMUTABLE;
 		}
 
-		MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED;
+		fat_save_attrs(inode, attr);
 		mark_inode_dirty(inode);
 up:
 		mnt_drop_write(filp->f_path.mnt);
@@ -274,7 +269,7 @@ static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
 
 	/*
 	 * Note, the basic check is already done by a caller of
-	 * (attr->ia_mode & ~MSDOS_VALID_MODE)
+	 * (attr->ia_mode & ~FAT_VALID_MODE)
 	 */
 
 	if (S_ISREG(inode->i_mode))
@@ -287,11 +282,18 @@ static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
 	/*
 	 * Of the r and x bits, all (subject to umask) must be present. Of the
 	 * w bits, either all (subject to umask) or none must be present.
+	 *
+	 * If fat_mode_can_hold_ro(inode) is false, can't change w bits.
 	 */
 	if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
 		return -EPERM;
-	if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
-		return -EPERM;
+	if (fat_mode_can_hold_ro(inode)) {
+		if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
+			return -EPERM;
+	} else {
+		if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
+			return -EPERM;
+	}
 
 	*mode_ptr &= S_IFMT | perm;
 
@@ -314,13 +316,15 @@ static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
 }
 
 #define TIMES_SET_FLAGS	(ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
+/* valid file mode bits */
+#define FAT_VALID_MODE	(S_IFREG | S_IFDIR | S_IRWXUGO)
 
 int fat_setattr(struct dentry *dentry, struct iattr *attr)
 {
 	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
 	struct inode *inode = dentry->d_inode;
-	int error = 0;
 	unsigned int ia_valid;
+	int error;
 
 	/*
 	 * Expand the file. Since inode_setattr() updates ->i_size
@@ -356,7 +360,7 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr)
 	    ((attr->ia_valid & ATTR_GID) &&
 	     (attr->ia_gid != sbi->options.fs_gid)) ||
 	    ((attr->ia_valid & ATTR_MODE) &&
-	     (attr->ia_mode & ~MSDOS_VALID_MODE)))
+	     (attr->ia_mode & ~FAT_VALID_MODE)))
 		error = -EPERM;
 
 	if (error) {
@@ -374,7 +378,8 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr)
 			attr->ia_valid &= ~ATTR_MODE;
 	}
 
-	error = inode_setattr(inode, attr);
+	if (attr->ia_valid)
+		error = inode_setattr(inode, attr);
 out:
 	return error;
 }
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 19eafbe3c37..bdd8fb7be2c 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -16,7 +16,6 @@
 #include <linux/slab.h>
 #include <linux/smp_lock.h>
 #include <linux/seq_file.h>
-#include <linux/msdos_fs.h>
 #include <linux/pagemap.h>
 #include <linux/mpage.h>
 #include <linux/buffer_head.h>
@@ -27,7 +26,9 @@
 #include <linux/uio.h>
 #include <linux/writeback.h>
 #include <linux/log2.h>
+#include <linux/hash.h>
 #include <asm/unaligned.h>
+#include "fat.h"
 
 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
 /* if user don't select VFAT, this is undefined. */
@@ -63,7 +64,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,
 	sector_t phys;
 	int err, offset;
 
-	err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
+	err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
 	if (err)
 		return err;
 	if (phys) {
@@ -93,7 +94,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,
 	*max_blocks = min(mapped_blocks, *max_blocks);
 	MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
 
-	err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
+	err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
 	if (err)
 		return err;
 
@@ -175,7 +176,7 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
 
 	if (rw == WRITE) {
 		/*
-		 * FIXME: blockdev_direct_IO() doesn't use ->prepare_write(),
+		 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
 		 * so we need to update the ->mmu_private to block boundary.
 		 *
 		 * But we must fill the remaining area or hole by nul for
@@ -198,7 +199,14 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
 
 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
 {
-	return generic_block_bmap(mapping, block, fat_get_block);
+	sector_t blocknr;
+
+	/* fat_get_cluster() assumes the requested blocknr isn't truncated. */
+	mutex_lock(&mapping->host->i_mutex);
+	blocknr = generic_block_bmap(mapping, block, fat_get_block);
+	mutex_unlock(&mapping->host->i_mutex);
+
+	return blocknr;
 }
 
 static const struct address_space_operations fat_aops = {
@@ -247,25 +255,21 @@ static void fat_hash_init(struct super_block *sb)
 		INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
 }
 
-static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
+static inline unsigned long fat_hash(loff_t i_pos)
 {
-	unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
-	tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
-	return tmp & FAT_HASH_MASK;
+	return hash_32(i_pos, FAT_HASH_BITS);
 }
 
 void fat_attach(struct inode *inode, loff_t i_pos)
 {
-	struct super_block *sb = inode->i_sb;
-	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+	struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
 
 	spin_lock(&sbi->inode_hash_lock);
 	MSDOS_I(inode)->i_pos = i_pos;
-	hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
-			sbi->inode_hashtable + fat_hash(sb, i_pos));
+	hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
 	spin_unlock(&sbi->inode_hash_lock);
 }
-
 EXPORT_SYMBOL_GPL(fat_attach);
 
 void fat_detach(struct inode *inode)
@@ -276,13 +280,12 @@ void fat_detach(struct inode *inode)
 	hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
 	spin_unlock(&sbi->inode_hash_lock);
 }
-
 EXPORT_SYMBOL_GPL(fat_detach);
 
 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
 {
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
-	struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
+	struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
 	struct hlist_node *_p;
 	struct msdos_inode_info *i;
 	struct inode *inode = NULL;
@@ -341,8 +344,7 @@ static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
 
 	if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
 		inode->i_generation &= ~1;
-		inode->i_mode = MSDOS_MKMODE(de->attr,
-			S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
+		inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
 		inode->i_op = sbi->dir_ops;
 		inode->i_fop = &fat_dir_operations;
 
@@ -359,10 +361,9 @@ static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
 		inode->i_nlink = fat_subdirs(inode);
 	} else { /* not a directory */
 		inode->i_generation |= 1;
-		inode->i_mode = MSDOS_MKMODE(de->attr,
-		    ((sbi->options.showexec && !is_exec(de->name + 8))
-			? S_IRUGO|S_IWUGO : S_IRWXUGO)
-		    & ~sbi->options.fs_fmask) | S_IFREG;
+		inode->i_mode = fat_make_mode(sbi, de->attr,
+			((sbi->options.showexec && !is_exec(de->name + 8))
+			 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
 		MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
 		if (sbi->fat_bits == 32)
 			MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
@@ -378,25 +379,16 @@ static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
 		if (sbi->options.sys_immutable)
 			inode->i_flags |= S_IMMUTABLE;
 	}
-	MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
+	fat_save_attrs(inode, de->attr);
+
 	inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
 			   & ~((loff_t)sbi->cluster_size - 1)) >> 9;
-	inode->i_mtime.tv_sec =
-		date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date),
-			      sbi->options.tz_utc);
-	inode->i_mtime.tv_nsec = 0;
+
+	fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
 	if (sbi->options.isvfat) {
-		int secs = de->ctime_cs / 100;
-		int csecs = de->ctime_cs % 100;
-		inode->i_ctime.tv_sec  =
-			date_dos2unix(le16_to_cpu(de->ctime),
-				      le16_to_cpu(de->cdate),
-				      sbi->options.tz_utc) + secs;
-		inode->i_ctime.tv_nsec = csecs * 10000000;
-		inode->i_atime.tv_sec =
-			date_dos2unix(0, le16_to_cpu(de->adate),
-				      sbi->options.tz_utc);
-		inode->i_atime.tv_nsec = 0;
+		fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
+				  de->cdate, de->ctime_cs);
+		fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
 	} else
 		inode->i_ctime = inode->i_atime = inode->i_mtime;
 
@@ -443,13 +435,8 @@ static void fat_delete_inode(struct inode *inode)
 
 static void fat_clear_inode(struct inode *inode)
 {
-	struct super_block *sb = inode->i_sb;
-	struct msdos_sb_info *sbi = MSDOS_SB(sb);
-
-	spin_lock(&sbi->inode_hash_lock);
 	fat_cache_inval_inode(inode);
-	hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
-	spin_unlock(&sbi->inode_hash_lock);
+	fat_detach(inode);
 }
 
 static void fat_write_super(struct super_block *sb)
@@ -555,6 +542,20 @@ static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
 	return 0;
 }
 
+static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
+				    struct inode *inode)
+{
+	loff_t i_pos;
+#if BITS_PER_LONG == 32
+	spin_lock(&sbi->inode_hash_lock);
+#endif
+	i_pos = MSDOS_I(inode)->i_pos;
+#if BITS_PER_LONG == 32
+	spin_unlock(&sbi->inode_hash_lock);
+#endif
+	return i_pos;
+}
+
 static int fat_write_inode(struct inode *inode, int wait)
 {
 	struct super_block *sb = inode->i_sb;
@@ -564,9 +565,12 @@ static int fat_write_inode(struct inode *inode, int wait)
 	loff_t i_pos;
 	int err;
 
+	if (inode->i_ino == MSDOS_ROOT_INO)
+		return 0;
+
 retry:
-	i_pos = MSDOS_I(inode)->i_pos;
-	if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
+	i_pos = fat_i_pos_read(sbi, inode);
+	if (!i_pos)
 		return 0;
 
 	bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
@@ -588,19 +592,17 @@ retry:
 		raw_entry->size = 0;
 	else
 		raw_entry->size = cpu_to_le32(inode->i_size);
-	raw_entry->attr = fat_attr(inode);
+	raw_entry->attr = fat_make_attrs(inode);
 	raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
 	raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
-	fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time,
-			  &raw_entry->date, sbi->options.tz_utc);
+	fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
+			  &raw_entry->date, NULL);
 	if (sbi->options.isvfat) {
 		__le16 atime;
-		fat_date_unix2dos(inode->i_ctime.tv_sec, &raw_entry->ctime,
-				  &raw_entry->cdate, sbi->options.tz_utc);
-		fat_date_unix2dos(inode->i_atime.tv_sec, &atime,
-				  &raw_entry->adate, sbi->options.tz_utc);
-		raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
-			inode->i_ctime.tv_nsec / 10000000;
+		fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
+				  &raw_entry->cdate, &raw_entry->ctime_cs);
+		fat_time_unix2fat(sbi, &inode->i_atime, &atime,
+				  &raw_entry->adate, NULL);
 	}
 	spin_unlock(&sbi->inode_hash_lock);
 	mark_buffer_dirty(bh);
@@ -819,8 +821,10 @@ static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
 			seq_puts(m, ",uni_xlate");
 		if (!opts->numtail)
 			seq_puts(m, ",nonumtail");
+		if (opts->rodir)
+			seq_puts(m, ",rodir");
 	}
-	if (sbi->options.flush)
+	if (opts->flush)
 		seq_puts(m, ",flush");
 	if (opts->tz_utc)
 		seq_puts(m, ",tz=UTC");
@@ -836,7 +840,7 @@ enum {
 	Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
 	Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
 	Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
-	Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_err,
+	Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err,
 };
 
 static const match_table_t fat_tokens = {
@@ -908,6 +912,7 @@ static const match_table_t vfat_tokens = {
 	{Opt_nonumtail_yes, "nonumtail=yes"},
 	{Opt_nonumtail_yes, "nonumtail=true"},
 	{Opt_nonumtail_yes, "nonumtail"},
+	{Opt_rodir, "rodir"},
 	{Opt_err, NULL}
 };
 
@@ -927,10 +932,13 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
 	opts->allow_utime = -1;
 	opts->codepage = fat_default_codepage;
 	opts->iocharset = fat_default_iocharset;
-	if (is_vfat)
+	if (is_vfat) {
 		opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
-	else
+		opts->rodir = 0;
+	} else {
 		opts->shortname = 0;
+		opts->rodir = 1;
+	}
 	opts->name_check = 'n';
 	opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK =  0;
 	opts->utf8 = opts->unicode_xlate = 0;
@@ -1081,6 +1089,9 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
 		case Opt_nonumtail_yes:		/* empty or 1 or yes or true */
 			opts->numtail = 0;	/* negated option */
 			break;
+		case Opt_rodir:
+			opts->rodir = 1;
+			break;
 
 		/* obsolete mount options */
 		case Opt_obsolate:
@@ -1126,7 +1137,7 @@ static int fat_read_root(struct inode *inode)
 	inode->i_gid = sbi->options.fs_gid;
 	inode->i_version++;
 	inode->i_generation = 0;
-	inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
+	inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
 	inode->i_op = sbi->dir_ops;
 	inode->i_fop = &fat_dir_operations;
 	if (sbi->fat_bits == 32) {
@@ -1143,7 +1154,7 @@ static int fat_read_root(struct inode *inode)
 	MSDOS_I(inode)->i_logstart = 0;
 	MSDOS_I(inode)->mmu_private = inode->i_size;
 
-	MSDOS_I(inode)->i_attrs = ATTR_NONE;
+	fat_save_attrs(inode, ATTR_DIR);
 	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
 	inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
 	inode->i_nlink = fat_subdirs(inode)+2;
diff --git a/fs/fat/misc.c b/fs/fat/misc.c
index 79fb98ad36d..ac39ebcc149 100644
--- a/fs/fat/misc.c
+++ b/fs/fat/misc.c
@@ -8,8 +8,8 @@
 
 #include <linux/module.h>
 #include <linux/fs.h>
-#include <linux/msdos_fs.h>
 #include <linux/buffer_head.h>
+#include "fat.h"
 
 /*
  * fat_fs_panic reports a severe file system problem and sets the file system
@@ -124,8 +124,9 @@ int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
 			mark_inode_dirty(inode);
 	}
 	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
-		fat_fs_panic(sb, "clusters badly computed (%d != %lu)",
-			new_fclus, inode->i_blocks >> (sbi->cluster_bits - 9));
+		fat_fs_panic(sb, "clusters badly computed (%d != %llu)",
+			     new_fclus,
+			     (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
 		fat_cache_inval_inode(inode);
 	}
 	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
@@ -135,65 +136,131 @@ int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
 
 extern struct timezone sys_tz;
 
+/*
+ * The epoch of FAT timestamp is 1980.
+ *     :  bits :     value
+ * date:  0 -  4: day	(1 -  31)
+ * date:  5 -  8: month	(1 -  12)
+ * date:  9 - 15: year	(0 - 127) from 1980
+ * time:  0 -  4: sec	(0 -  29) 2sec counts
+ * time:  5 - 10: min	(0 -  59)
+ * time: 11 - 15: hour	(0 -  23)
+ */
+#define SECS_PER_MIN	60
+#define SECS_PER_HOUR	(60 * 60)
+#define SECS_PER_DAY	(SECS_PER_HOUR * 24)
+#define UNIX_SECS_1980	315532800L
+#if BITS_PER_LONG == 64
+#define UNIX_SECS_2108	4354819200L
+#endif
+/* days between 1.1.70 and 1.1.80 (2 leap days) */
+#define DAYS_DELTA	(365 * 10 + 2)
+/* 120 (2100 - 1980) isn't leap year */
+#define YEAR_2100	120
+#define IS_LEAP_YEAR(y)	(!((y) & 3) && (y) != YEAR_2100)
+
 /* Linear day numbers of the respective 1sts in non-leap years. */
-static int day_n[] = {
-   /* Jan  Feb  Mar  Apr   May  Jun  Jul  Aug  Sep  Oct  Nov  Dec */
-	0,  31,  59,  90,  120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, 0
+static time_t days_in_year[] = {
+	/* Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec */
+	0,   0,  31,  59,  90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
 };
 
-/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */
-int date_dos2unix(unsigned short time, unsigned short date, int tz_utc)
+/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
+void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
+		       __le16 __time, __le16 __date, u8 time_cs)
 {
-	int month, year, secs;
+	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
+	time_t second, day, leap_day, month, year;
 
-	/*
-	 * first subtract and mask after that... Otherwise, if
-	 * date == 0, bad things happen
-	 */
-	month = ((date >> 5) - 1) & 15;
-	year = date >> 9;
-	secs = (time & 31)*2+60*((time >> 5) & 63)+(time >> 11)*3600+86400*
-	    ((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 &&
-	    month < 2 ? 1 : 0)+3653);
-			/* days since 1.1.70 plus 80's leap day */
-	if (!tz_utc)
-		secs += sys_tz.tz_minuteswest*60;
-	return secs;
+	year  = date >> 9;
+	month = max(1, (date >> 5) & 0xf);
+	day   = max(1, date & 0x1f) - 1;
+
+	leap_day = (year + 3) / 4;
+	if (year > YEAR_2100)		/* 2100 isn't leap year */
+		leap_day--;
+	if (IS_LEAP_YEAR(year) && month > 2)
+		leap_day++;
+
+	second =  (time & 0x1f) << 1;
+	second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
+	second += (time >> 11) * SECS_PER_HOUR;
+	second += (year * 365 + leap_day
+		   + days_in_year[month] + day
+		   + DAYS_DELTA) * SECS_PER_DAY;
+
+	if (!sbi->options.tz_utc)
+		second += sys_tz.tz_minuteswest * SECS_PER_MIN;
+
+	if (time_cs) {
+		ts->tv_sec = second + (time_cs / 100);
+		ts->tv_nsec = (time_cs % 100) * 10000000;
+	} else {
+		ts->tv_sec = second;
+		ts->tv_nsec = 0;
+	}
 }
 
-/* Convert linear UNIX date to a MS-DOS time/date pair. */
-void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date, int tz_utc)
+/* Convert linear UNIX date to a FAT time/date pair. */
+void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
+		       __le16 *time, __le16 *date, u8 *time_cs)
 {
-	int day, year, nl_day, month;
+	time_t second = ts->tv_sec;
+	time_t day, leap_day, month, year;
 
-	if (!tz_utc)
-		unix_date -= sys_tz.tz_minuteswest*60;
+	if (!sbi->options.tz_utc)
+		second -= sys_tz.tz_minuteswest * SECS_PER_MIN;
 
 	/* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
-	if (unix_date < 315532800)
-		unix_date = 315532800;
-
-	*time = cpu_to_le16((unix_date % 60)/2+(((unix_date/60) % 60) << 5)+
-	    (((unix_date/3600) % 24) << 11));
-	day = unix_date/86400-3652;
-	year = day/365;
-	if ((year+3)/4+365*year > day)
+	if (second < UNIX_SECS_1980) {
+		*time = 0;
+		*date = cpu_to_le16((0 << 9) | (1 << 5) | 1);
+		if (time_cs)
+			*time_cs = 0;
+		return;
+	}
+#if BITS_PER_LONG == 64
+	if (second >= UNIX_SECS_2108) {
+		*time = cpu_to_le16((23 << 11) | (59 << 5) | 29);
+		*date = cpu_to_le16((127 << 9) | (12 << 5) | 31);
+		if (time_cs)
+			*time_cs = 199;
+		return;
+	}
+#endif
+
+	day = second / SECS_PER_DAY - DAYS_DELTA;
+	year = day / 365;
+	leap_day = (year + 3) / 4;
+	if (year > YEAR_2100)		/* 2100 isn't leap year */
+		leap_day--;
+	if (year * 365 + leap_day > day)
 		year--;
-	day -= (year+3)/4+365*year;
-	if (day == 59 && !(year & 3)) {
-		nl_day = day;
+	leap_day = (year + 3) / 4;
+	if (year > YEAR_2100)		/* 2100 isn't leap year */
+		leap_day--;
+	day -= year * 365 + leap_day;
+
+	if (IS_LEAP_YEAR(year) && day == days_in_year[3]) {
 		month = 2;
 	} else {
-		nl_day = (year & 3) || day <= 59 ? day : day-1;
-		for (month = 0; month < 12; month++) {
-			if (day_n[month] > nl_day)
+		if (IS_LEAP_YEAR(year) && day > days_in_year[3])
+			day--;
+		for (month = 1; month < 12; month++) {
+			if (days_in_year[month + 1] > day)
 				break;
 		}
 	}
-	*date = cpu_to_le16(nl_day-day_n[month-1]+1+(month << 5)+(year << 9));
-}
+	day -= days_in_year[month];
 
-EXPORT_SYMBOL_GPL(fat_date_unix2dos);
+	*time = cpu_to_le16(((second / SECS_PER_HOUR) % 24) << 11
+			    | ((second / SECS_PER_MIN) % 60) << 5
+			    | (second % SECS_PER_MIN) >> 1);
+	*date = cpu_to_le16((year << 9) | (month << 5) | (day + 1));
+	if (time_cs)
+		*time_cs = (ts->tv_sec & 1) * 100 + ts->tv_nsec / 10000000;
+}
+EXPORT_SYMBOL_GPL(fat_time_unix2fat);
 
 int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
 {
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
new file mode 100644
index 00000000000..7ba03a4acbe
--- /dev/null
+++ b/fs/fat/namei_msdos.c
@@ -0,0 +1,706 @@
+/*
+ *  linux/fs/msdos/namei.c
+ *
+ *  Written 1992,1993 by Werner Almesberger
+ *  Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
+ *  Rewritten for constant inumbers 1999 by Al Viro
+ */
+
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/buffer_head.h>
+#include <linux/smp_lock.h>
+#include "fat.h"
+
+/* Characters that are undesirable in an MS-DOS file name */
+static unsigned char bad_chars[] = "*?<>|\"";
+static unsigned char bad_if_strict[] = "+=,; ";
+
+/***** Formats an MS-DOS file name. Rejects invalid names. */
+static int msdos_format_name(const unsigned char *name, int len,
+			     unsigned char *res, struct fat_mount_options *opts)
+	/*
+	 * name is the proposed name, len is its length, res is
+	 * the resulting name, opts->name_check is either (r)elaxed,
+	 * (n)ormal or (s)trict, opts->dotsOK allows dots at the
+	 * beginning of name (for hidden files)
+	 */
+{
+	unsigned char *walk;
+	unsigned char c;
+	int space;
+
+	if (name[0] == '.') {	/* dotfile because . and .. already done */
+		if (opts->dotsOK) {
+			/* Get rid of dot - test for it elsewhere */
+			name++;
+			len--;
+		} else
+			return -EINVAL;
+	}
+	/*
+	 * disallow names that _really_ start with a dot
+	 */
+	space = 1;
+	c = 0;
+	for (walk = res; len && walk - res < 8; walk++) {
+		c = *name++;
+		len--;
+		if (opts->name_check != 'r' && strchr(bad_chars, c))
+			return -EINVAL;
+		if (opts->name_check == 's' && strchr(bad_if_strict, c))
+			return -EINVAL;
+		if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
+			return -EINVAL;
+		if (c < ' ' || c == ':' || c == '\\')
+			return -EINVAL;
+	/*
+	 * 0xE5 is legal as a first character, but we must substitute
+	 * 0x05 because 0xE5 marks deleted files.  Yes, DOS really
+	 * does this.
+	 * It seems that Microsoft hacked DOS to support non-US
+	 * characters after the 0xE5 character was already in use to
+	 * mark deleted files.
+	 */
+		if ((res == walk) && (c == 0xE5))
+			c = 0x05;
+		if (c == '.')
+			break;
+		space = (c == ' ');
+		*walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
+	}
+	if (space)
+		return -EINVAL;
+	if (opts->name_check == 's' && len && c != '.') {
+		c = *name++;
+		len--;
+		if (c != '.')
+			return -EINVAL;
+	}
+	while (c != '.' && len--)
+		c = *name++;
+	if (c == '.') {
+		while (walk - res < 8)
+			*walk++ = ' ';
+		while (len > 0 && walk - res < MSDOS_NAME) {
+			c = *name++;
+			len--;
+			if (opts->name_check != 'r' && strchr(bad_chars, c))
+				return -EINVAL;
+			if (opts->name_check == 's' &&
+			    strchr(bad_if_strict, c))
+				return -EINVAL;
+			if (c < ' ' || c == ':' || c == '\\')
+				return -EINVAL;
+			if (c == '.') {
+				if (opts->name_check == 's')
+					return -EINVAL;
+				break;
+			}
+			if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
+				return -EINVAL;
+			space = c == ' ';
+			if (!opts->nocase && c >= 'a' && c <= 'z')
+				*walk++ = c - 32;
+			else
+				*walk++ = c;
+		}
+		if (space)
+			return -EINVAL;
+		if (opts->name_check == 's' && len)
+			return -EINVAL;
+	}
+	while (walk - res < MSDOS_NAME)
+		*walk++ = ' ';
+
+	return 0;
+}
+
+/***** Locates a directory entry.  Uses unformatted name. */
+static int msdos_find(struct inode *dir, const unsigned char *name, int len,
+		      struct fat_slot_info *sinfo)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
+	unsigned char msdos_name[MSDOS_NAME];
+	int err;
+
+	err = msdos_format_name(name, len, msdos_name, &sbi->options);
+	if (err)
+		return -ENOENT;
+
+	err = fat_scan(dir, msdos_name, sinfo);
+	if (!err && sbi->options.dotsOK) {
+		if (name[0] == '.') {
+			if (!(sinfo->de->attr & ATTR_HIDDEN))
+				err = -ENOENT;
+		} else {
+			if (sinfo->de->attr & ATTR_HIDDEN)
+				err = -ENOENT;
+		}
+		if (err)
+			brelse(sinfo->bh);
+	}
+	return err;
+}
+
+/*
+ * Compute the hash for the msdos 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 msdos fs routines will
+ * return ENOENT or EINVAL as appropriate.
+ */
+static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
+{
+	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
+	unsigned char msdos_name[MSDOS_NAME];
+	int error;
+
+	error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
+	if (!error)
+		qstr->hash = full_name_hash(msdos_name, MSDOS_NAME);
+	return 0;
+}
+
+/*
+ * Compare two msdos names. If either of the names are invalid,
+ * we fall back to doing the standard name comparison.
+ */
+static int msdos_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
+{
+	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
+	unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
+	int error;
+
+	error = msdos_format_name(a->name, a->len, a_msdos_name, options);
+	if (error)
+		goto old_compare;
+	error = msdos_format_name(b->name, b->len, b_msdos_name, options);
+	if (error)
+		goto old_compare;
+	error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
+out:
+	return error;
+
+old_compare:
+	error = 1;
+	if (a->len == b->len)
+		error = memcmp(a->name, b->name, a->len);
+	goto out;
+}
+
+static struct dentry_operations msdos_dentry_operations = {
+	.d_hash		= msdos_hash,
+	.d_compare	= msdos_cmp,
+};
+
+/*
+ * AV. Wrappers for FAT sb operations. Is it wise?
+ */
+
+/***** Get inode using directory and name */
+static struct dentry *msdos_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;
+	int err;
+
+	lock_super(sb);
+
+	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &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;
+	}
+out:
+	unlock_super(sb);
+	dentry->d_op = &msdos_dentry_operations;
+	dentry = d_splice_alias(inode, dentry);
+	if (dentry)
+		dentry->d_op = &msdos_dentry_operations;
+	return dentry;
+
+error:
+	unlock_super(sb);
+	return ERR_PTR(err);
+}
+
+/***** Creates a directory entry (name is already formatted). */
+static int msdos_add_entry(struct inode *dir, const unsigned char *name,
+			   int is_dir, int is_hid, int cluster,
+			   struct timespec *ts, struct fat_slot_info *sinfo)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
+	struct msdos_dir_entry de;
+	__le16 time, date;
+	int err;
+
+	memcpy(de.name, name, MSDOS_NAME);
+	de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
+	if (is_hid)
+		de.attr |= ATTR_HIDDEN;
+	de.lcase = 0;
+	fat_time_unix2fat(sbi, ts, &time, &date, NULL);
+	de.cdate = de.adate = 0;
+	de.ctime = 0;
+	de.ctime_cs = 0;
+	de.time = time;
+	de.date = date;
+	de.start = cpu_to_le16(cluster);
+	de.starthi = cpu_to_le16(cluster >> 16);
+	de.size = 0;
+
+	err = fat_add_entries(dir, &de, 1, sinfo);
+	if (err)
+		return err;
+
+	dir->i_ctime = dir->i_mtime = *ts;
+	if (IS_DIRSYNC(dir))
+		(void)fat_sync_inode(dir);
+	else
+		mark_inode_dirty(dir);
+
+	return 0;
+}
+
+/***** Create a file */
+static int msdos_create(struct inode *dir, struct dentry *dentry, int mode,
+			struct nameidata *nd)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = NULL;
+	struct fat_slot_info sinfo;
+	struct timespec ts;
+	unsigned char msdos_name[MSDOS_NAME];
+	int err, is_hid;
+
+	lock_super(sb);
+
+	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
+				msdos_name, &MSDOS_SB(sb)->options);
+	if (err)
+		goto out;
+	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
+	/* Have to do it due to foo vs. .foo conflicts */
+	if (!fat_scan(dir, msdos_name, &sinfo)) {
+		brelse(sinfo.bh);
+		err = -EINVAL;
+		goto out;
+	}
+
+	ts = CURRENT_TIME_SEC;
+	err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
+	if (err)
+		goto out;
+	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_mtime = inode->i_atime = inode->i_ctime = ts;
+	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
+
+	d_instantiate(dentry, inode);
+out:
+	unlock_super(sb);
+	if (!err)
+		err = fat_flush_inodes(sb, dir, inode);
+	return err;
+}
+
+/***** Remove a directory */
+static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = dentry->d_inode;
+	struct fat_slot_info sinfo;
+	int err;
+
+	lock_super(sb);
+	/*
+	 * Check whether the directory is not in use, then check
+	 * whether it is empty.
+	 */
+	err = fat_dir_empty(inode);
+	if (err)
+		goto out;
+	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &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_ctime = CURRENT_TIME_SEC;
+	fat_detach(inode);
+out:
+	unlock_super(sb);
+	if (!err)
+		err = fat_flush_inodes(sb, dir, inode);
+
+	return err;
+}
+
+/***** Make a directory */
+static int msdos_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct fat_slot_info sinfo;
+	struct inode *inode;
+	unsigned char msdos_name[MSDOS_NAME];
+	struct timespec ts;
+	int err, is_hid, cluster;
+
+	lock_super(sb);
+
+	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
+				msdos_name, &MSDOS_SB(sb)->options);
+	if (err)
+		goto out;
+	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
+	/* foo vs .foo situation */
+	if (!fat_scan(dir, msdos_name, &sinfo)) {
+		brelse(sinfo.bh);
+		err = -EINVAL;
+		goto out;
+	}
+
+	ts = CURRENT_TIME_SEC;
+	cluster = fat_alloc_new_dir(dir, &ts);
+	if (cluster < 0) {
+		err = cluster;
+		goto out;
+	}
+	err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
+	if (err)
+		goto out_free;
+	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_nlink = 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);
+
+	unlock_super(sb);
+	fat_flush_inodes(sb, dir, inode);
+	return 0;
+
+out_free:
+	fat_free_clusters(dir, cluster);
+out:
+	unlock_super(sb);
+	return err;
+}
+
+/***** Unlink a file */
+static int msdos_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct super_block *sb= inode->i_sb;
+	struct fat_slot_info sinfo;
+	int err;
+
+	lock_super(sb);
+	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
+	if (err)
+		goto out;
+
+	err = fat_remove_entries(dir, &sinfo);	/* and releases bh */
+	if (err)
+		goto out;
+	clear_nlink(inode);
+	inode->i_ctime = CURRENT_TIME_SEC;
+	fat_detach(inode);
+out:
+	unlock_super(sb);
+	if (!err)
+		err = fat_flush_inodes(sb, dir, inode);
+
+	return err;
+}
+
+static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
+			   struct dentry *old_dentry,
+			   struct inode *new_dir, unsigned char *new_name,
+			   struct dentry *new_dentry, int is_hid)
+{
+	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 dotdot_i_pos, new_i_pos;
+	int err, old_attrs, 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;
+
+	err = fat_scan(old_dir, old_name, &old_sinfo);
+	if (err) {
+		err = -EIO;
+		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;
+		}
+	}
+
+	old_attrs = MSDOS_I(old_inode)->i_attrs;
+	err = fat_scan(new_dir, new_name, &sinfo);
+	if (!err) {
+		if (!new_inode) {
+			/* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
+			if (sinfo.de != old_sinfo.de) {
+				err = -EINVAL;
+				goto out;
+			}
+			if (is_hid)
+				MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
+			else
+				MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
+			if (IS_DIRSYNC(old_dir)) {
+				err = fat_sync_inode(old_inode);
+				if (err) {
+					MSDOS_I(old_inode)->i_attrs = old_attrs;
+					goto out;
+				}
+			} else
+				mark_inode_dirty(old_inode);
+
+			old_dir->i_version++;
+			old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
+			if (IS_DIRSYNC(old_dir))
+				(void)fat_sync_inode(old_dir);
+			else
+				mark_inode_dirty(old_dir);
+			goto out;
+		}
+	}
+
+	ts = CURRENT_TIME_SEC;
+	if (new_inode) {
+		if (err)
+			goto out;
+		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 = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 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_hid)
+		MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
+	else
+		MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
+	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;
+		}
+		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);
+	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);
+	MSDOS_I(old_inode)->i_attrs = old_attrs;
+	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_panic(new_dir->i_sb,
+			     "%s: Filesystem corrupted (i_pos %lld)",
+			     __func__, sinfo.i_pos);
+	}
+	goto out;
+}
+
+/***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
+static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct super_block *sb = old_dir->i_sb;
+	unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
+	int err, is_hid;
+
+	lock_super(sb);
+
+	err = msdos_format_name(old_dentry->d_name.name,
+				old_dentry->d_name.len, old_msdos_name,
+				&MSDOS_SB(old_dir->i_sb)->options);
+	if (err)
+		goto out;
+	err = msdos_format_name(new_dentry->d_name.name,
+				new_dentry->d_name.len, new_msdos_name,
+				&MSDOS_SB(new_dir->i_sb)->options);
+	if (err)
+		goto out;
+
+	is_hid =
+	     (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
+
+	err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
+			      new_dir, new_msdos_name, new_dentry, is_hid);
+out:
+	unlock_super(sb);
+	if (!err)
+		err = fat_flush_inodes(sb, old_dir, new_dir);
+	return err;
+}
+
+static const struct inode_operations msdos_dir_inode_operations = {
+	.create		= msdos_create,
+	.lookup		= msdos_lookup,
+	.unlink		= msdos_unlink,
+	.mkdir		= msdos_mkdir,
+	.rmdir		= msdos_rmdir,
+	.rename		= msdos_rename,
+	.setattr	= fat_setattr,
+	.getattr	= fat_getattr,
+};
+
+static int msdos_fill_super(struct super_block *sb, void *data, int silent)
+{
+	int res;
+
+	res = fat_fill_super(sb, data, silent, &msdos_dir_inode_operations, 0);
+	if (res)
+		return res;
+
+	sb->s_flags |= MS_NOATIME;
+	sb->s_root->d_op = &msdos_dentry_operations;
+	return 0;
+}
+
+static int msdos_get_sb(struct file_system_type *fs_type,
+			int flags, const char *dev_name,
+			void *data, struct vfsmount *mnt)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, data, msdos_fill_super,
+			   mnt);
+}
+
+static struct file_system_type msdos_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "msdos",
+	.get_sb		= msdos_get_sb,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+
+static int __init init_msdos_fs(void)
+{
+	return register_filesystem(&msdos_fs_type);
+}
+
+static void __exit exit_msdos_fs(void)
+{
+	unregister_filesystem(&msdos_fs_type);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Werner Almesberger");
+MODULE_DESCRIPTION("MS-DOS filesystem support");
+
+module_init(init_msdos_fs)
+module_exit(exit_msdos_fs)
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
new file mode 100644
index 00000000000..bf326d4356a
--- /dev/null
+++ b/fs/fat/namei_vfat.c
@@ -0,0 +1,1098 @@
+/*
+ *  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/ctype.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+#include <linux/namei.h>
+#include "fat.h"
+
+/*
+ * 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 (dentry->d_time != dentry->d_parent->d_inode->i_version)
+		ret = 0;
+	spin_unlock(&dentry->d_lock);
+	return ret;
+}
+
+static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	/* This is not negative dentry. Always valid. */
+	if (dentry->d_inode)
+		return 1;
+	return vfat_revalidate_shortname(dentry);
+}
+
+static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
+{
+	/*
+	 * 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 (dentry->d_inode)
+		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 (!nd)
+		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 (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) {
+		if (nd->flags & LOOKUP_CREATE)
+			return 0;
+	}
+
+	return vfat_revalidate_shortname(dentry);
+}
+
+/* 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_ci_dentry_ops = {
+	.d_revalidate	= vfat_revalidate_ci,
+	.d_hash		= vfat_hashi,
+	.d_compare	= vfat_cmpi,
+};
+
+static 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[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, PATH_MAX);
+
+		/*
+		 * We stripped '.'s before and set len appropriately,
+		 * but utf8_mbstowcs doesn't care about len
+		 */
+		*outlen -= (name_len - len);
+
+		if (*outlen > 255)
+			return -ENAMETOOLONG;
+
+		op = &outname[*outlen * sizeof(wchar_t)];
+	} else {
+		if (nls) {
+			for (i = 0, ip = name, op = outname, *outlen = 0;
+			     i < len && *outlen <= 255;
+			     *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;
+				}
+			}
+			if (i < len)
+				return -ENAMETOOLONG;
+		} else {
+			for (i = 0, ip = name, op = outname, *outlen = 0;
+			     i < len && *outlen <= 255;
+			     i++, *outlen += 1)
+			{
+				*op++ = *ip++;
+				*op++ = 0;
+			}
+			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;
+	de->start = cpu_to_le16(cluster);
+	de->starthi = cpu_to_le16(cluster >> 16);
+	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);
+}
+
+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;
+	struct dentry *alias;
+	int err;
+
+	lock_super(sb);
+
+	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 && !(alias->d_flags & DCACHE_DISCONNECTED)) {
+		/*
+		 * This inode has non 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);
+		unlock_super(sb);
+		return alias;
+	}
+out:
+	unlock_super(sb);
+	dentry->d_op = sb->s_root->d_op;
+	dentry->d_time = dentry->d_parent->d_inode->i_version;
+	dentry = d_splice_alias(inode, dentry);
+	if (dentry) {
+		dentry->d_op = sb->s_root->d_op;
+		dentry->d_time = dentry->d_parent->d_inode->i_version;
+	}
+	return dentry;
+
+error:
+	unlock_super(sb);
+	return ERR_PTR(err);
+}
+
+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_super(sb);
+
+	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_super(sb);
+	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;
+
+	lock_super(sb);
+
+	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:
+	unlock_super(sb);
+
+	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;
+
+	lock_super(sb);
+
+	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:
+	unlock_super(sb);
+
+	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_super(sb);
+
+	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++;
+	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_super(sb);
+	return 0;
+
+out_free:
+	fat_free_clusters(dir, cluster);
+out:
+	unlock_super(sb);
+	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 dotdot_i_pos, 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;
+	lock_super(sb);
+	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) {
+		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) {
+		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;
+		}
+		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);
+	unlock_super(sb);
+
+	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, 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_panic(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 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_ci_dentry_ops;
+	else
+		sb->s_root->d_op = &vfat_dentry_ops;
+
+	return 0;
+}
+
+static int vfat_get_sb(struct file_system_type *fs_type,
+		       int flags, const char *dev_name,
+		       void *data, struct vfsmount *mnt)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super,
+			   mnt);
+}
+
+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)