1 files changed, 602 insertions, 360 deletions

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index ad6998a92c3..756aead10d9 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -18,14 +18,15 @@
 #include <linux/pagemap.h>
 #include <linux/mpage.h>
 #include <linux/buffer_head.h>
-#include <linux/exportfs.h>
 #include <linux/mount.h>
+#include <linux/aio.h>
 #include <linux/vfs.h>
 #include <linux/parser.h>
 #include <linux/uio.h>
 #include <linux/writeback.h>
 #include <linux/log2.h>
 #include <linux/hash.h>
+#include <linux/blkdev.h>
 #include <asm/unaligned.h>
 #include "fat.h"
 
@@ -34,9 +35,71 @@
 #define CONFIG_FAT_DEFAULT_IOCHARSET	""
 #endif
 
+#define KB_IN_SECTORS 2
+
+/*
+ * A deserialized copy of the on-disk structure laid out in struct
+ * fat_boot_sector.
+ */
+struct fat_bios_param_block {
+	u16	fat_sector_size;
+	u8	fat_sec_per_clus;
+	u16	fat_reserved;
+	u8	fat_fats;
+	u16	fat_dir_entries;
+	u16	fat_sectors;
+	u16	fat_fat_length;
+	u32	fat_total_sect;
+
+	u8	fat16_state;
+	u32	fat16_vol_id;
+
+	u32	fat32_length;
+	u32	fat32_root_cluster;
+	u16	fat32_info_sector;
+	u8	fat32_state;
+	u32	fat32_vol_id;
+};
+
 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
 
+static struct fat_floppy_defaults {
+	unsigned nr_sectors;
+	unsigned sec_per_clus;
+	unsigned dir_entries;
+	unsigned media;
+	unsigned fat_length;
+} floppy_defaults[] = {
+{
+	.nr_sectors = 160 * KB_IN_SECTORS,
+	.sec_per_clus = 1,
+	.dir_entries = 64,
+	.media = 0xFE,
+	.fat_length = 1,
+},
+{
+	.nr_sectors = 180 * KB_IN_SECTORS,
+	.sec_per_clus = 1,
+	.dir_entries = 64,
+	.media = 0xFC,
+	.fat_length = 2,
+},
+{
+	.nr_sectors = 320 * KB_IN_SECTORS,
+	.sec_per_clus = 2,
+	.dir_entries = 112,
+	.media = 0xFF,
+	.fat_length = 1,
+},
+{
+	.nr_sectors = 360 * KB_IN_SECTORS,
+	.sec_per_clus = 2,
+	.dir_entries = 112,
+	.media = 0xFD,
+	.fat_length = 2,
+},
+};
 
 static int fat_add_cluster(struct inode *inode)
 {
@@ -146,7 +209,7 @@ static void fat_write_failed(struct address_space *mapping, loff_t to)
 	struct inode *inode = mapping->host;
 
 	if (to > inode->i_size) {
-		truncate_pagecache(inode, to, inode->i_size);
+		truncate_pagecache(inode, inode->i_size);
 		fat_truncate_blocks(inode, inode->i_size);
 	}
 }
@@ -184,12 +247,13 @@ static int fat_write_end(struct file *file, struct address_space *mapping,
 }
 
 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
-			     const struct iovec *iov,
-			     loff_t offset, unsigned long nr_segs)
+			     struct iov_iter *iter,
+			     loff_t offset)
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
 	struct inode *inode = mapping->host;
+	size_t count = iov_iter_count(iter);
 	ssize_t ret;
 
 	if (rw == WRITE) {
@@ -202,7 +266,7 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
 		 *
 		 * Return 0, and fallback to normal buffered write.
 		 */
-		loff_t size = offset + iov_length(iov, nr_segs);
+		loff_t size = offset + count;
 		if (MSDOS_I(inode)->mmu_private < size)
 			return 0;
 	}
@@ -211,10 +275,9 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
 	 * FAT need to use the DIO_LOCKING for avoiding the race
 	 * condition of fat_get_block() and ->truncate().
 	 */
-	ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
-				 iov, offset, nr_segs, fat_get_block, NULL);
+	ret = blockdev_direct_IO(rw, iocb, inode, iter, offset, fat_get_block);
 	if (ret < 0 && (rw & WRITE))
-		fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
+		fat_write_failed(mapping, offset + count);
 
 	return ret;
 }
@@ -224,9 +287,9 @@ static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
 	sector_t blocknr;
 
 	/* fat_get_cluster() assumes the requested blocknr isn't truncated. */
-	down_read(&mapping->host->i_alloc_sem);
+	down_read(&MSDOS_I(mapping->host)->truncate_lock);
 	blocknr = generic_block_bmap(mapping, block, fat_get_block);
-	up_read(&mapping->host->i_alloc_sem);
+	up_read(&MSDOS_I(mapping->host)->truncate_lock);
 
 	return blocknr;
 }
@@ -236,7 +299,6 @@ static const struct address_space_operations fat_aops = {
 	.readpages	= fat_readpages,
 	.writepage	= fat_writepage,
 	.writepages	= fat_writepages,
-	.sync_page	= block_sync_page,
 	.write_begin	= fat_write_begin,
 	.write_end	= fat_write_end,
 	.direct_IO	= fat_direct_IO,
@@ -282,15 +344,42 @@ static inline unsigned long fat_hash(loff_t i_pos)
 	return hash_32(i_pos, FAT_HASH_BITS);
 }
 
+static void dir_hash_init(struct super_block *sb)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	int i;
+
+	spin_lock_init(&sbi->dir_hash_lock);
+	for (i = 0; i < FAT_HASH_SIZE; i++)
+		INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
+}
+
 void fat_attach(struct inode *inode, loff_t i_pos)
 {
 	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, head);
-	spin_unlock(&sbi->inode_hash_lock);
+	if (inode->i_ino != MSDOS_ROOT_INO) {
+		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, head);
+		spin_unlock(&sbi->inode_hash_lock);
+	}
+
+	/* If NFS support is enabled, cache the mapping of start cluster
+	 * to directory inode. This is used during reconnection of
+	 * dentries to the filesystem root.
+	 */
+	if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
+		struct hlist_head *d_head = sbi->dir_hashtable;
+		d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
+
+		spin_lock(&sbi->dir_hash_lock);
+		hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
+		spin_unlock(&sbi->dir_hash_lock);
+	}
 }
 EXPORT_SYMBOL_GPL(fat_attach);
 
@@ -301,6 +390,12 @@ void fat_detach(struct inode *inode)
 	MSDOS_I(inode)->i_pos = 0;
 	hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
 	spin_unlock(&sbi->inode_hash_lock);
+
+	if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
+		spin_lock(&sbi->dir_hash_lock);
+		hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
+		spin_unlock(&sbi->dir_hash_lock);
+	}
 }
 EXPORT_SYMBOL_GPL(fat_detach);
 
@@ -308,12 +403,11 @@ 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(i_pos);
-	struct hlist_node *_p;
 	struct msdos_inode_info *i;
 	struct inode *inode = NULL;
 
 	spin_lock(&sbi->inode_hash_lock);
-	hlist_for_each_entry(i, _p, head, i_fat_hash) {
+	hlist_for_each_entry(i, head, i_fat_hash) {
 		BUG_ON(i->vfs_inode.i_sb != sb);
 		if (i->i_pos != i_pos)
 			continue;
@@ -327,7 +421,7 @@ struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
 
 static int is_exec(unsigned char *extension)
 {
-	unsigned char *exe_extensions = "EXECOMBAT", *walk;
+	unsigned char exe_extensions[] = "EXECOMBAT", *walk;
 
 	for (walk = exe_extensions; *walk; walk += 3)
 		if (!strncmp(extension, walk, 3))
@@ -353,7 +447,7 @@ static int fat_calc_dir_size(struct inode *inode)
 }
 
 /* doesn't deal with root inode */
-static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
+int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
 {
 	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 	int error;
@@ -370,25 +464,20 @@ static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
 		inode->i_op = sbi->dir_ops;
 		inode->i_fop = &fat_dir_operations;
 
-		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);
-
+		MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
 		MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
 		error = fat_calc_dir_size(inode);
 		if (error < 0)
 			return error;
 		MSDOS_I(inode)->mmu_private = inode->i_size;
 
-		inode->i_nlink = fat_subdirs(inode);
+		set_nlink(inode, fat_subdirs(inode));
 	} else { /* not a directory */
 		inode->i_generation |= 1;
 		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);
+		MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
 
 		MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
 		inode->i_size = le32_to_cpu(de->size);
@@ -417,12 +506,25 @@ static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
 	return 0;
 }
 
+static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
+{
+	if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
+		mutex_lock(&sbi->nfs_build_inode_lock);
+}
+
+static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
+{
+	if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
+		mutex_unlock(&sbi->nfs_build_inode_lock);
+}
+
 struct inode *fat_build_inode(struct super_block *sb,
 			struct msdos_dir_entry *de, loff_t i_pos)
 {
 	struct inode *inode;
 	int err;
 
+	fat_lock_build_inode(MSDOS_SB(sb));
 	inode = fat_iget(sb, i_pos);
 	if (inode)
 		goto out;
@@ -442,6 +544,7 @@ struct inode *fat_build_inode(struct super_block *sb,
 	fat_attach(inode, i_pos);
 	insert_inode_hash(inode);
 out:
+	fat_unlock_build_inode(MSDOS_SB(sb));
 	return inode;
 }
 
@@ -449,58 +552,84 @@ EXPORT_SYMBOL_GPL(fat_build_inode);
 
 static void fat_evict_inode(struct inode *inode)
 {
-	truncate_inode_pages(&inode->i_data, 0);
+	truncate_inode_pages_final(&inode->i_data);
 	if (!inode->i_nlink) {
 		inode->i_size = 0;
 		fat_truncate_blocks(inode, 0);
 	}
 	invalidate_inode_buffers(inode);
-	end_writeback(inode);
+	clear_inode(inode);
 	fat_cache_inval_inode(inode);
 	fat_detach(inode);
 }
 
-static void fat_write_super(struct super_block *sb)
+static void fat_set_state(struct super_block *sb,
+			unsigned int set, unsigned int force)
 {
-	lock_super(sb);
-	sb->s_dirt = 0;
+	struct buffer_head *bh;
+	struct fat_boot_sector *b;
+	struct msdos_sb_info *sbi = sb->s_fs_info;
+
+	/* do not change any thing if mounted read only */
+	if ((sb->s_flags & MS_RDONLY) && !force)
+		return;
+
+	/* do not change state if fs was dirty */
+	if (sbi->dirty) {
+		/* warn only on set (mount). */
+		if (set)
+			fat_msg(sb, KERN_WARNING, "Volume was not properly "
+				"unmounted. Some data may be corrupt. "
+				"Please run fsck.");
+		return;
+	}
 
-	if (!(sb->s_flags & MS_RDONLY))
-		fat_clusters_flush(sb);
-	unlock_super(sb);
-}
+	bh = sb_bread(sb, 0);
+	if (bh == NULL) {
+		fat_msg(sb, KERN_ERR, "unable to read boot sector "
+			"to mark fs as dirty");
+		return;
+	}
 
-static int fat_sync_fs(struct super_block *sb, int wait)
-{
-	int err = 0;
+	b = (struct fat_boot_sector *) bh->b_data;
 
-	if (sb->s_dirt) {
-		lock_super(sb);
-		sb->s_dirt = 0;
-		err = fat_clusters_flush(sb);
-		unlock_super(sb);
+	if (sbi->fat_bits == 32) {
+		if (set)
+			b->fat32.state |= FAT_STATE_DIRTY;
+		else
+			b->fat32.state &= ~FAT_STATE_DIRTY;
+	} else /* fat 16 and 12 */ {
+		if (set)
+			b->fat16.state |= FAT_STATE_DIRTY;
+		else
+			b->fat16.state &= ~FAT_STATE_DIRTY;
 	}
 
-	return err;
+	mark_buffer_dirty(bh);
+	sync_dirty_buffer(bh);
+	brelse(bh);
+}
+
+static void delayed_free(struct rcu_head *p)
+{
+	struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
+	unload_nls(sbi->nls_disk);
+	unload_nls(sbi->nls_io);
+	if (sbi->options.iocharset != fat_default_iocharset)
+		kfree(sbi->options.iocharset);
+	kfree(sbi);
 }
 
 static void fat_put_super(struct super_block *sb)
 {
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 
-	if (sb->s_dirt)
-		fat_write_super(sb);
+	fat_set_state(sb, 0, 0);
 
+	iput(sbi->fsinfo_inode);
 	iput(sbi->fat_inode);
 
-	unload_nls(sbi->nls_disk);
-	unload_nls(sbi->nls_io);
-
-	if (sbi->options.iocharset != fat_default_iocharset)
-		kfree(sbi->options.iocharset);
-
-	sb->s_fs_info = NULL;
-	kfree(sbi);
+	call_rcu(&sbi->rcu, delayed_free);
 }
 
 static struct kmem_cache *fat_inode_cachep;
@@ -511,14 +640,22 @@ static struct inode *fat_alloc_inode(struct super_block *sb)
 	ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
 	if (!ei)
 		return NULL;
+
+	init_rwsem(&ei->truncate_lock);
 	return &ei->vfs_inode;
 }
 
-static void fat_destroy_inode(struct inode *inode)
+static void fat_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
 	kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
 }
 
+static void fat_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, fat_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
@@ -528,6 +665,7 @@ static void init_once(void *foo)
 	ei->cache_valid_id = FAT_CACHE_VALID + 1;
 	INIT_LIST_HEAD(&ei->cache_lru);
 	INIT_HLIST_NODE(&ei->i_fat_hash);
+	INIT_HLIST_NODE(&ei->i_dir_hash);
 	inode_init_once(&ei->vfs_inode);
 }
 
@@ -545,13 +683,30 @@ static int __init fat_init_inodecache(void)
 
 static void __exit fat_destroy_inodecache(void)
 {
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
 	kmem_cache_destroy(fat_inode_cachep);
 }
 
 static int fat_remount(struct super_block *sb, int *flags, char *data)
 {
+	int new_rdonly;
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 	*flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
+
+	sync_filesystem(sb);
+
+	/* make sure we update state on remount. */
+	new_rdonly = *flags & MS_RDONLY;
+	if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
+		if (new_rdonly)
+			fat_set_state(sb, 0, 0);
+		else
+			fat_set_state(sb, 1, 1);
+	}
 	return 0;
 }
 
@@ -575,25 +730,12 @@ static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_bavail = sbi->free_clusters;
 	buf->f_fsid.val[0] = (u32)id;
 	buf->f_fsid.val[1] = (u32)(id >> 32);
-	buf->f_namelen = sbi->options.isvfat ? FAT_LFN_LEN : 12;
+	buf->f_namelen =
+		(sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
 
 	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;
@@ -601,7 +743,8 @@ static int __fat_write_inode(struct inode *inode, int wait)
 	struct buffer_head *bh;
 	struct msdos_dir_entry *raw_entry;
 	loff_t i_pos;
-	int err;
+	sector_t blocknr;
+	int err, offset;
 
 	if (inode->i_ino == MSDOS_ROOT_INO)
 		return 0;
@@ -611,10 +754,11 @@ retry:
 	if (!i_pos)
 		return 0;
 
-	bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
+	fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
+	bh = sb_bread(sb, blocknr);
 	if (!bh) {
-		printk(KERN_ERR "FAT: unable to read inode block "
-		       "for updating (i_pos %lld)\n", i_pos);
+		fat_msg(sb, KERN_ERR, "unable to read inode block "
+		       "for updating (i_pos %lld)", i_pos);
 		return -EIO;
 	}
 	spin_lock(&sbi->inode_hash_lock);
@@ -624,15 +768,13 @@ retry:
 		goto retry;
 	}
 
-	raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
-	    [i_pos & (sbi->dir_per_block - 1)];
+	raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
 	if (S_ISDIR(inode->i_mode))
 		raw_entry->size = 0;
 	else
 		raw_entry->size = cpu_to_le32(inode->i_size);
 	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_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
 	fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
 			  &raw_entry->date, NULL);
 	if (sbi->options.isvfat) {
@@ -653,7 +795,18 @@ retry:
 
 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
 {
-	return __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
+	int err;
+
+	if (inode->i_ino == MSDOS_FSINFO_INO) {
+		struct super_block *sb = inode->i_sb;
+
+		mutex_lock(&MSDOS_SB(sb)->s_lock);
+		err = fat_clusters_flush(sb);
+		mutex_unlock(&MSDOS_SB(sb)->s_lock);
+	} else
+		err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
+
+	return err;
 }
 
 int fat_sync_inode(struct inode *inode)
@@ -663,165 +816,38 @@ int fat_sync_inode(struct inode *inode)
 
 EXPORT_SYMBOL_GPL(fat_sync_inode);
 
-static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
+static int fat_show_options(struct seq_file *m, struct dentry *root);
 static const struct super_operations fat_sops = {
 	.alloc_inode	= fat_alloc_inode,
 	.destroy_inode	= fat_destroy_inode,
 	.write_inode	= fat_write_inode,
 	.evict_inode	= fat_evict_inode,
 	.put_super	= fat_put_super,
-	.write_super	= fat_write_super,
-	.sync_fs	= fat_sync_fs,
 	.statfs		= fat_statfs,
 	.remount_fs	= fat_remount,
 
 	.show_options	= fat_show_options,
 };
 
-/*
- * a FAT file handle with fhtype 3 is
- *  0/  i_ino - for fast, reliable lookup if still in the cache
- *  1/  i_generation - to see if i_ino is still valid
- *          bit 0 == 0 iff directory
- *  2/  i_pos(8-39) - if ino has changed, but still in cache
- *  3/  i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
- *  4/  i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
- *
- * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
- * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
- * of i_logstart is used to store the directory entry offset.
- */
-
-static struct dentry *fat_fh_to_dentry(struct super_block *sb,
-		struct fid *fid, int fh_len, int fh_type)
-{
-	struct inode *inode = NULL;
-	struct dentry *result;
-	u32 *fh = fid->raw;
-
-	if (fh_len < 5 || fh_type != 3)
-		return NULL;
-
-	inode = ilookup(sb, fh[0]);
-	if (!inode || inode->i_generation != fh[1]) {
-		if (inode)
-			iput(inode);
-		inode = NULL;
-	}
-	if (!inode) {
-		loff_t i_pos;
-		int i_logstart = fh[3] & 0x0fffffff;
-
-		i_pos = (loff_t)fh[2] << 8;
-		i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
-
-		/* try 2 - see if i_pos is in F-d-c
-		 * require i_logstart to be the same
-		 * Will fail if you truncate and then re-write
-		 */
-
-		inode = fat_iget(sb, i_pos);
-		if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
-			iput(inode);
-			inode = NULL;
-		}
-	}
-
-	/*
-	 * For now, do nothing if the inode is not found.
-	 *
-	 * What we could do is:
-	 *
-	 *	- follow the file starting at fh[4], and record the ".." entry,
-	 *	  and the name of the fh[2] entry.
-	 *	- then follow the ".." file finding the next step up.
-	 *
-	 * This way we build a path to the root of the tree. If this works, we
-	 * lookup the path and so get this inode into the cache.  Finally try
-	 * the fat_iget lookup again.  If that fails, then we are totally out
-	 * of luck.  But all that is for another day
-	 */
-	result = d_obtain_alias(inode);
-	if (!IS_ERR(result))
-		result->d_op = sb->s_root->d_op;
-	return result;
-}
-
-static int
-fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
-{
-	int len = *lenp;
-	struct inode *inode =  de->d_inode;
-	u32 ipos_h, ipos_m, ipos_l;
-
-	if (len < 5)
-		return 255; /* no room */
-
-	ipos_h = MSDOS_I(inode)->i_pos >> 8;
-	ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
-	ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
-	*lenp = 5;
-	fh[0] = inode->i_ino;
-	fh[1] = inode->i_generation;
-	fh[2] = ipos_h;
-	fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
-	spin_lock(&de->d_lock);
-	fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
-	spin_unlock(&de->d_lock);
-	return 3;
-}
-
-static struct dentry *fat_get_parent(struct dentry *child)
-{
-	struct super_block *sb = child->d_sb;
-	struct buffer_head *bh;
-	struct msdos_dir_entry *de;
-	loff_t i_pos;
-	struct dentry *parent;
-	struct inode *inode;
-	int err;
-
-	lock_super(sb);
-
-	err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
-	if (err) {
-		parent = ERR_PTR(err);
-		goto out;
-	}
-	inode = fat_build_inode(sb, de, i_pos);
-	brelse(bh);
-
-	parent = d_obtain_alias(inode);
-	if (!IS_ERR(parent))
-		parent->d_op = sb->s_root->d_op;
-out:
-	unlock_super(sb);
-
-	return parent;
-}
-
-static const struct export_operations fat_export_ops = {
-	.encode_fh	= fat_encode_fh,
-	.fh_to_dentry	= fat_fh_to_dentry,
-	.get_parent	= fat_get_parent,
-};
-
-static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
+static int fat_show_options(struct seq_file *m, struct dentry *root)
 {
-	struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
+	struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
 	struct fat_mount_options *opts = &sbi->options;
 	int isvfat = opts->isvfat;
 
-	if (opts->fs_uid != 0)
-		seq_printf(m, ",uid=%u", opts->fs_uid);
-	if (opts->fs_gid != 0)
-		seq_printf(m, ",gid=%u", opts->fs_gid);
+	if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
+		seq_printf(m, ",uid=%u",
+				from_kuid_munged(&init_user_ns, opts->fs_uid));
+	if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
+		seq_printf(m, ",gid=%u",
+				from_kgid_munged(&init_user_ns, opts->fs_gid));
 	seq_printf(m, ",fmask=%04o", opts->fs_fmask);
 	seq_printf(m, ",dmask=%04o", opts->fs_dmask);
 	if (opts->allow_utime)
 		seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
 	if (sbi->nls_disk)
-		seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
+		/* strip "cp" prefix from displayed option */
+		seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
 	if (isvfat) {
 		if (sbi->nls_io)
 			seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
@@ -871,16 +897,26 @@ static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
 	}
 	if (opts->flush)
 		seq_puts(m, ",flush");
-	if (opts->tz_utc)
-		seq_puts(m, ",tz=UTC");
+	if (opts->tz_set) {
+		if (opts->time_offset)
+			seq_printf(m, ",time_offset=%d", opts->time_offset);
+		else
+			seq_puts(m, ",tz=UTC");
+	}
 	if (opts->errors == FAT_ERRORS_CONT)
 		seq_puts(m, ",errors=continue");
 	else if (opts->errors == FAT_ERRORS_PANIC)
 		seq_puts(m, ",errors=panic");
 	else
 		seq_puts(m, ",errors=remount-ro");
+	if (opts->nfs == FAT_NFS_NOSTALE_RO)
+		seq_puts(m, ",nfs=nostale_ro");
+	else if (opts->nfs)
+		seq_puts(m, ",nfs=stale_rw");
 	if (opts->discard)
 		seq_puts(m, ",discard");
+	if (opts->dos1xfloppy)
+		seq_puts(m, ",dos1xfloppy");
 
 	return 0;
 }
@@ -893,8 +929,9 @@ 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_rodir, Opt_err_cont,
-	Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err,
+	Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
+	Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
+	Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
 };
 
 static const match_table_t fat_tokens = {
@@ -919,21 +956,26 @@ static const match_table_t fat_tokens = {
 	{Opt_immutable, "sys_immutable"},
 	{Opt_flush, "flush"},
 	{Opt_tz_utc, "tz=UTC"},
+	{Opt_time_offset, "time_offset=%d"},
 	{Opt_err_cont, "errors=continue"},
 	{Opt_err_panic, "errors=panic"},
 	{Opt_err_ro, "errors=remount-ro"},
 	{Opt_discard, "discard"},
-	{Opt_obsolate, "conv=binary"},
-	{Opt_obsolate, "conv=text"},
-	{Opt_obsolate, "conv=auto"},
-	{Opt_obsolate, "conv=b"},
-	{Opt_obsolate, "conv=t"},
-	{Opt_obsolate, "conv=a"},
-	{Opt_obsolate, "fat=%u"},
-	{Opt_obsolate, "blocksize=%u"},
-	{Opt_obsolate, "cvf_format=%20s"},
-	{Opt_obsolate, "cvf_options=%100s"},
-	{Opt_obsolate, "posix"},
+	{Opt_nfs_stale_rw, "nfs"},
+	{Opt_nfs_stale_rw, "nfs=stale_rw"},
+	{Opt_nfs_nostale_ro, "nfs=nostale_ro"},
+	{Opt_dos1xfloppy, "dos1xfloppy"},
+	{Opt_obsolete, "conv=binary"},
+	{Opt_obsolete, "conv=text"},
+	{Opt_obsolete, "conv=auto"},
+	{Opt_obsolete, "conv=b"},
+	{Opt_obsolete, "conv=t"},
+	{Opt_obsolete, "conv=a"},
+	{Opt_obsolete, "fat=%u"},
+	{Opt_obsolete, "blocksize=%u"},
+	{Opt_obsolete, "cvf_format=%20s"},
+	{Opt_obsolete, "cvf_options=%100s"},
+	{Opt_obsolete, "posix"},
 	{Opt_err, NULL},
 };
 static const match_table_t msdos_tokens = {
@@ -974,8 +1016,8 @@ static const match_table_t vfat_tokens = {
 	{Opt_err, NULL}
 };
 
-static int parse_options(char *options, int is_vfat, int silent, int *debug,
-			 struct fat_mount_options *opts)
+static int parse_options(struct super_block *sb, char *options, int is_vfat,
+			 int silent, int *debug, struct fat_mount_options *opts)
 {
 	char *p;
 	substring_t args[MAX_OPT_ARGS];
@@ -1002,7 +1044,8 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
 	opts->utf8 = opts->unicode_xlate = 0;
 	opts->numtail = 1;
 	opts->usefree = opts->nocase = 0;
-	opts->tz_utc = 0;
+	opts->tz_set = 0;
+	opts->nfs = 0;
 	opts->errors = FAT_ERRORS_RO;
 	*debug = 0;
 
@@ -1057,44 +1100,57 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
 			break;
 		case Opt_uid:
 			if (match_int(&args[0], &option))
-				return 0;
-			opts->fs_uid = option;
+				return -EINVAL;
+			opts->fs_uid = make_kuid(current_user_ns(), option);
+			if (!uid_valid(opts->fs_uid))
+				return -EINVAL;
 			break;
 		case Opt_gid:
 			if (match_int(&args[0], &option))
-				return 0;
-			opts->fs_gid = option;
+				return -EINVAL;
+			opts->fs_gid = make_kgid(current_user_ns(), option);
+			if (!gid_valid(opts->fs_gid))
+				return -EINVAL;
 			break;
 		case Opt_umask:
 			if (match_octal(&args[0], &option))
-				return 0;
+				return -EINVAL;
 			opts->fs_fmask = opts->fs_dmask = option;
 			break;
 		case Opt_dmask:
 			if (match_octal(&args[0], &option))
-				return 0;
+				return -EINVAL;
 			opts->fs_dmask = option;
 			break;
 		case Opt_fmask:
 			if (match_octal(&args[0], &option))
-				return 0;
+				return -EINVAL;
 			opts->fs_fmask = option;
 			break;
 		case Opt_allow_utime:
 			if (match_octal(&args[0], &option))
-				return 0;
+				return -EINVAL;
 			opts->allow_utime = option & (S_IWGRP | S_IWOTH);
 			break;
 		case Opt_codepage:
 			if (match_int(&args[0], &option))
-				return 0;
+				return -EINVAL;
 			opts->codepage = option;
 			break;
 		case Opt_flush:
 			opts->flush = 1;
 			break;
+		case Opt_time_offset:
+			if (match_int(&args[0], &option))
+				return -EINVAL;
+			if (option < -12 * 60 || option > 12 * 60)
+				return -EINVAL;
+			opts->tz_set = 1;
+			opts->time_offset = option;
+			break;
 		case Opt_tz_utc:
-			opts->tz_utc = 1;
+			opts->tz_set = 1;
+			opts->time_offset = 0;
 			break;
 		case Opt_err_cont:
 			opts->errors = FAT_ERRORS_CONT;
@@ -1105,6 +1161,15 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
 		case Opt_err_ro:
 			opts->errors = FAT_ERRORS_RO;
 			break;
+		case Opt_nfs_stale_rw:
+			opts->nfs = FAT_NFS_STALE_RW;
+			break;
+		case Opt_nfs_nostale_ro:
+			opts->nfs = FAT_NFS_NOSTALE_RO;
+			break;
+		case Opt_dos1xfloppy:
+			opts->dos1xfloppy = 1;
+			break;
 
 		/* msdos specific */
 		case Opt_dots:
@@ -1165,16 +1230,16 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
 			break;
 
 		/* obsolete mount options */
-		case Opt_obsolate:
-			printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
-			       "not supported now\n", p);
+		case Opt_obsolete:
+			fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
+			       "not supported now", p);
 			break;
 		/* unknown option */
 		default:
 			if (!silent) {
-				printk(KERN_ERR
-				       "FAT: Unrecognized mount option \"%s\" "
-				       "or missing value\n", p);
+				fat_msg(sb, KERN_ERR,
+				       "Unrecognized mount option \"%s\" "
+				       "or missing value", p);
 			}
 			return -EINVAL;
 		}
@@ -1183,9 +1248,9 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
 out:
 	/* UTF-8 doesn't provide FAT semantics */
 	if (!strcmp(opts->iocharset, "utf8")) {
-		printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
+		fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
 		       " for FAT filesystems, filesystem will be "
-		       "case sensitive!\n");
+		       "case sensitive!");
 	}
 
 	/* If user doesn't specify allow_utime, it's initialized from dmask. */
@@ -1193,6 +1258,10 @@ out:
 		opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
 	if (opts->unicode_xlate)
 		opts->utf8 = 0;
+	if (opts->nfs == FAT_NFS_NOSTALE_RO) {
+		sb->s_flags |= MS_RDONLY;
+		sb->s_export_op = &fat_export_ops_nostale;
+	}
 
 	return 0;
 }
@@ -1203,7 +1272,7 @@ static int fat_read_root(struct inode *inode)
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 	int error;
 
-	MSDOS_I(inode)->i_pos = 0;
+	MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
 	inode->i_uid = sbi->options.fs_uid;
 	inode->i_gid = sbi->options.fs_gid;
 	inode->i_version++;
@@ -1228,25 +1297,201 @@ static int fat_read_root(struct inode *inode)
 	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;
+	set_nlink(inode, fat_subdirs(inode)+2);
 
 	return 0;
 }
 
+static unsigned long calc_fat_clusters(struct super_block *sb)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+	/* Divide first to avoid overflow */
+	if (sbi->fat_bits != 12) {
+		unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
+		return ent_per_sec * sbi->fat_length;
+	}
+
+	return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
+}
+
+static bool fat_bpb_is_zero(struct fat_boot_sector *b)
+{
+	if (get_unaligned_le16(&b->sector_size))
+		return false;
+	if (b->sec_per_clus)
+		return false;
+	if (b->reserved)
+		return false;
+	if (b->fats)
+		return false;
+	if (get_unaligned_le16(&b->dir_entries))
+		return false;
+	if (get_unaligned_le16(&b->sectors))
+		return false;
+	if (b->media)
+		return false;
+	if (b->fat_length)
+		return false;
+	if (b->secs_track)
+		return false;
+	if (b->heads)
+		return false;
+	return true;
+}
+
+static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
+	int silent, struct fat_bios_param_block *bpb)
+{
+	int error = -EINVAL;
+
+	/* Read in BPB ... */
+	memset(bpb, 0, sizeof(*bpb));
+	bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
+	bpb->fat_sec_per_clus = b->sec_per_clus;
+	bpb->fat_reserved = le16_to_cpu(b->reserved);
+	bpb->fat_fats = b->fats;
+	bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
+	bpb->fat_sectors = get_unaligned_le16(&b->sectors);
+	bpb->fat_fat_length = le16_to_cpu(b->fat_length);
+	bpb->fat_total_sect = le32_to_cpu(b->total_sect);
+
+	bpb->fat16_state = b->fat16.state;
+	bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
+
+	bpb->fat32_length = le32_to_cpu(b->fat32.length);
+	bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
+	bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
+	bpb->fat32_state = b->fat32.state;
+	bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
+
+	/* Validate this looks like a FAT filesystem BPB */
+	if (!bpb->fat_reserved) {
+		if (!silent)
+			fat_msg(sb, KERN_ERR,
+				"bogus number of reserved sectors");
+		goto out;
+	}
+	if (!bpb->fat_fats) {
+		if (!silent)
+			fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
+		goto out;
+	}
+
+	/*
+	 * Earlier we checked here that b->secs_track and b->head are nonzero,
+	 * but it turns out valid FAT filesystems can have zero there.
+	 */
+
+	if (!fat_valid_media(b->media)) {
+		if (!silent)
+			fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
+				(unsigned)b->media);
+		goto out;
+	}
+
+	if (!is_power_of_2(bpb->fat_sector_size)
+	    || (bpb->fat_sector_size < 512)
+	    || (bpb->fat_sector_size > 4096)) {
+		if (!silent)
+			fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
+			       (unsigned)bpb->fat_sector_size);
+		goto out;
+	}
+
+	if (!is_power_of_2(bpb->fat_sec_per_clus)) {
+		if (!silent)
+			fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
+				(unsigned)bpb->fat_sec_per_clus);
+		goto out;
+	}
+
+	error = 0;
+
+out:
+	return error;
+}
+
+static int fat_read_static_bpb(struct super_block *sb,
+	struct fat_boot_sector *b, int silent,
+	struct fat_bios_param_block *bpb)
+{
+	static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
+
+	struct fat_floppy_defaults *fdefaults = NULL;
+	int error = -EINVAL;
+	sector_t bd_sects;
+	unsigned i;
+
+	bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
+
+	/* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
+	if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
+		if (!silent)
+			fat_msg(sb, KERN_ERR,
+				"%s; no bootstrapping code", notdos1x);
+		goto out;
+	}
+
+	/*
+	 * If any value in this region is non-zero, it isn't archaic
+	 * DOS.
+	 */
+	if (!fat_bpb_is_zero(b)) {
+		if (!silent)
+			fat_msg(sb, KERN_ERR,
+				"%s; DOS 2.x BPB is non-zero", notdos1x);
+		goto out;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
+		if (floppy_defaults[i].nr_sectors == bd_sects) {
+			fdefaults = &floppy_defaults[i];
+			break;
+		}
+	}
+
+	if (fdefaults == NULL) {
+		if (!silent)
+			fat_msg(sb, KERN_WARNING,
+				"This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
+				(u64)bd_sects);
+		goto out;
+	}
+
+	if (!silent)
+		fat_msg(sb, KERN_INFO,
+			"This looks like a DOS 1.x volume; assuming default BPB values");
+
+	memset(bpb, 0, sizeof(*bpb));
+	bpb->fat_sector_size = SECTOR_SIZE;
+	bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
+	bpb->fat_reserved = 1;
+	bpb->fat_fats = 2;
+	bpb->fat_dir_entries = fdefaults->dir_entries;
+	bpb->fat_sectors = fdefaults->nr_sectors;
+	bpb->fat_fat_length = fdefaults->fat_length;
+
+	error = 0;
+
+out:
+	return error;
+}
+
 /*
  * Read the super block of an MS-DOS FS.
  */
-int fat_fill_super(struct super_block *sb, void *data, int silent,
-		   const struct inode_operations *fs_dir_inode_ops, int isvfat)
+int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
+		   void (*setup)(struct super_block *))
 {
 	struct inode *root_inode = NULL, *fat_inode = NULL;
+	struct inode *fsinfo_inode = NULL;
 	struct buffer_head *bh;
-	struct fat_boot_sector *b;
+	struct fat_bios_param_block bpb;
 	struct msdos_sb_info *sbi;
 	u16 logical_sector_size;
 	u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
 	int debug;
-	unsigned int media;
 	long error;
 	char buf[50];
 
@@ -1265,131 +1510,104 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 	sb->s_magic = MSDOS_SUPER_MAGIC;
 	sb->s_op = &fat_sops;
 	sb->s_export_op = &fat_export_ops;
-	sbi->dir_ops = fs_dir_inode_ops;
+	mutex_init(&sbi->nfs_build_inode_lock);
 	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
 			     DEFAULT_RATELIMIT_BURST);
 
-	error = parse_options(data, isvfat, silent, &debug, &sbi->options);
+	error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
 	if (error)
 		goto out_fail;
 
+	setup(sb); /* flavour-specific stuff that needs options */
+
 	error = -EIO;
 	sb_min_blocksize(sb, 512);
 	bh = sb_bread(sb, 0);
 	if (bh == NULL) {
-		printk(KERN_ERR "FAT: unable to read boot sector\n");
+		fat_msg(sb, KERN_ERR, "unable to read boot sector");
 		goto out_fail;
 	}
 
-	b = (struct fat_boot_sector *) bh->b_data;
-	if (!b->reserved) {
-		if (!silent)
-			printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
-		brelse(bh);
-		goto out_invalid;
-	}
-	if (!b->fats) {
-		if (!silent)
-			printk(KERN_ERR "FAT: bogus number of FAT structure\n");
-		brelse(bh);
-		goto out_invalid;
-	}
-
-	/*
-	 * Earlier we checked here that b->secs_track and b->head are nonzero,
-	 * but it turns out valid FAT filesystems can have zero there.
-	 */
+	error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
+		&bpb);
+	if (error == -EINVAL && sbi->options.dos1xfloppy)
+		error = fat_read_static_bpb(sb,
+			(struct fat_boot_sector *)bh->b_data, silent, &bpb);
+	brelse(bh);
 
-	media = b->media;
-	if (!fat_valid_media(media)) {
-		if (!silent)
-			printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
-			       media);
-		brelse(bh);
+	if (error == -EINVAL)
 		goto out_invalid;
-	}
-	logical_sector_size = get_unaligned_le16(&b->sector_size);
-	if (!is_power_of_2(logical_sector_size)
-	    || (logical_sector_size < 512)
-	    || (logical_sector_size > 4096)) {
-		if (!silent)
-			printk(KERN_ERR "FAT: bogus logical sector size %u\n",
-			       logical_sector_size);
-		brelse(bh);
-		goto out_invalid;
-	}
-	sbi->sec_per_clus = b->sec_per_clus;
-	if (!is_power_of_2(sbi->sec_per_clus)) {
-		if (!silent)
-			printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
-			       sbi->sec_per_clus);
-		brelse(bh);
-		goto out_invalid;
-	}
+	else if (error)
+		goto out_fail;
+
+	logical_sector_size = bpb.fat_sector_size;
+	sbi->sec_per_clus = bpb.fat_sec_per_clus;
 
+	error = -EIO;
 	if (logical_sector_size < sb->s_blocksize) {
-		printk(KERN_ERR "FAT: logical sector size too small for device"
-		       " (logical sector size = %u)\n", logical_sector_size);
-		brelse(bh);
+		fat_msg(sb, KERN_ERR, "logical sector size too small for device"
+		       " (logical sector size = %u)", logical_sector_size);
 		goto out_fail;
 	}
+
 	if (logical_sector_size > sb->s_blocksize) {
-		brelse(bh);
+		struct buffer_head *bh_resize;
 
 		if (!sb_set_blocksize(sb, logical_sector_size)) {
-			printk(KERN_ERR "FAT: unable to set blocksize %u\n",
+			fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
 			       logical_sector_size);
 			goto out_fail;
 		}
-		bh = sb_bread(sb, 0);
-		if (bh == NULL) {
-			printk(KERN_ERR "FAT: unable to read boot sector"
-			       " (logical sector size = %lu)\n",
+
+		/* Verify that the larger boot sector is fully readable */
+		bh_resize = sb_bread(sb, 0);
+		if (bh_resize == NULL) {
+			fat_msg(sb, KERN_ERR, "unable to read boot sector"
+			       " (logical sector size = %lu)",
 			       sb->s_blocksize);
 			goto out_fail;
 		}
-		b = (struct fat_boot_sector *) bh->b_data;
+		brelse(bh_resize);
 	}
 
+	mutex_init(&sbi->s_lock);
 	sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
 	sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
-	sbi->fats = b->fats;
+	sbi->fats = bpb.fat_fats;
 	sbi->fat_bits = 0;		/* Don't know yet */
-	sbi->fat_start = le16_to_cpu(b->reserved);
-	sbi->fat_length = le16_to_cpu(b->fat_length);
+	sbi->fat_start = bpb.fat_reserved;
+	sbi->fat_length = bpb.fat_fat_length;
 	sbi->root_cluster = 0;
 	sbi->free_clusters = -1;	/* Don't know yet */
 	sbi->free_clus_valid = 0;
 	sbi->prev_free = FAT_START_ENT;
+	sb->s_maxbytes = 0xffffffff;
 
-	if (!sbi->fat_length && b->fat32_length) {
+	if (!sbi->fat_length && bpb.fat32_length) {
 		struct fat_boot_fsinfo *fsinfo;
 		struct buffer_head *fsinfo_bh;
 
 		/* Must be FAT32 */
 		sbi->fat_bits = 32;
-		sbi->fat_length = le32_to_cpu(b->fat32_length);
-		sbi->root_cluster = le32_to_cpu(b->root_cluster);
-
-		sb->s_maxbytes = 0xffffffff;
+		sbi->fat_length = bpb.fat32_length;
+		sbi->root_cluster = bpb.fat32_root_cluster;
 
 		/* MC - if info_sector is 0, don't multiply by 0 */
-		sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
+		sbi->fsinfo_sector = bpb.fat32_info_sector;
 		if (sbi->fsinfo_sector == 0)
 			sbi->fsinfo_sector = 1;
 
 		fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
 		if (fsinfo_bh == NULL) {
-			printk(KERN_ERR "FAT: bread failed, FSINFO block"
-			       " (sector = %lu)\n", sbi->fsinfo_sector);
-			brelse(bh);
+			fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
+			       " (sector = %lu)", sbi->fsinfo_sector);
 			goto out_fail;
 		}
 
 		fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
 		if (!IS_FSINFO(fsinfo)) {
-			printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
-			       "0x%08x, 0x%08x (sector = %lu)\n",
+			fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
+			       "0x%08x, 0x%08x (sector = %lu)",
 			       le32_to_cpu(fsinfo->signature1),
 			       le32_to_cpu(fsinfo->signature2),
 			       sbi->fsinfo_sector);
@@ -1403,39 +1621,49 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 		brelse(fsinfo_bh);
 	}
 
+	/* interpret volume ID as a little endian 32 bit integer */
+	if (sbi->fat_bits == 32)
+		sbi->vol_id = bpb.fat32_vol_id;
+	else /* fat 16 or 12 */
+		sbi->vol_id = bpb.fat16_vol_id;
+
 	sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
 	sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
 
 	sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
-	sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
+	sbi->dir_entries = bpb.fat_dir_entries;
 	if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
 		if (!silent)
-			printk(KERN_ERR "FAT: bogus directroy-entries per block"
-			       " (%u)\n", sbi->dir_entries);
-		brelse(bh);
+			fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
+			       " (%u)", sbi->dir_entries);
 		goto out_invalid;
 	}
 
 	rootdir_sectors = sbi->dir_entries
 		* sizeof(struct msdos_dir_entry) / sb->s_blocksize;
 	sbi->data_start = sbi->dir_start + rootdir_sectors;
-	total_sectors = get_unaligned_le16(&b->sectors);
+	total_sectors = bpb.fat_sectors;
 	if (total_sectors == 0)
-		total_sectors = le32_to_cpu(b->total_sect);
+		total_sectors = bpb.fat_total_sect;
 
 	total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
 
 	if (sbi->fat_bits != 32)
 		sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
 
+	/* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
+	if (sbi->fat_bits == 32)
+		sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
+	else /* fat 16 or 12 */
+		sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
+
 	/* check that FAT table does not overflow */
-	fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
+	fat_clusters = calc_fat_clusters(sb);
 	total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
 	if (total_clusters > MAX_FAT(sb)) {
 		if (!silent)
-			printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
+			fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
 			       total_clusters);
-		brelse(bh);
 		goto out_invalid;
 	}
 
@@ -1448,10 +1676,9 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 	if (sbi->prev_free < FAT_START_ENT)
 		sbi->prev_free = FAT_START_ENT;
 
-	brelse(bh);
-
 	/* set up enough so that it can read an inode */
 	fat_hash_init(sb);
+	dir_hash_init(sb);
 	fat_ent_access_init(sb);
 
 	/*
@@ -1466,7 +1693,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 	sprintf(buf, "cp%d", sbi->options.codepage);
 	sbi->nls_disk = load_nls(buf);
 	if (!sbi->nls_disk) {
-		printk(KERN_ERR "FAT: codepage %s not found\n", buf);
+		fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
 		goto out_fail;
 	}
 
@@ -1474,7 +1701,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 	if (sbi->options.isvfat) {
 		sbi->nls_io = load_nls(sbi->options.iocharset);
 		if (!sbi->nls_io) {
-			printk(KERN_ERR "FAT: IO charset %s not found\n",
+			fat_msg(sb, KERN_ERR, "IO charset %s not found",
 			       sbi->options.iocharset);
 			goto out_fail;
 		}
@@ -1486,35 +1713,54 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 		goto out_fail;
 	MSDOS_I(fat_inode)->i_pos = 0;
 	sbi->fat_inode = fat_inode;
+
+	fsinfo_inode = new_inode(sb);
+	if (!fsinfo_inode)
+		goto out_fail;
+	fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
+	sbi->fsinfo_inode = fsinfo_inode;
+	insert_inode_hash(fsinfo_inode);
+
 	root_inode = new_inode(sb);
 	if (!root_inode)
 		goto out_fail;
 	root_inode->i_ino = MSDOS_ROOT_INO;
 	root_inode->i_version = 1;
 	error = fat_read_root(root_inode);
-	if (error < 0)
+	if (error < 0) {
+		iput(root_inode);
 		goto out_fail;
+	}
 	error = -ENOMEM;
 	insert_inode_hash(root_inode);
-	sb->s_root = d_alloc_root(root_inode);
+	fat_attach(root_inode, 0);
+	sb->s_root = d_make_root(root_inode);
 	if (!sb->s_root) {
-		printk(KERN_ERR "FAT: get root inode failed\n");
+		fat_msg(sb, KERN_ERR, "get root inode failed");
 		goto out_fail;
 	}
 
+	if (sbi->options.discard) {
+		struct request_queue *q = bdev_get_queue(sb->s_bdev);
+		if (!blk_queue_discard(q))
+			fat_msg(sb, KERN_WARNING,
+					"mounting with \"discard\" option, but "
+					"the device does not support discard");
+	}
+
+	fat_set_state(sb, 1, 0);
 	return 0;
 
 out_invalid:
 	error = -EINVAL;
 	if (!silent)
-		printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
-		       " on dev %s.\n", sb->s_id);
+		fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
 
 out_fail:
+	if (fsinfo_inode)
+		iput(fsinfo_inode);
 	if (fat_inode)
 		iput(fat_inode);
-	if (root_inode)
-		iput(root_inode);
 	unload_nls(sbi->nls_io);
 	unload_nls(sbi->nls_disk);
 	if (sbi->options.iocharset != fat_default_iocharset)
@@ -1536,18 +1782,14 @@ static int writeback_inode(struct inode *inode)
 {
 
 	int ret;
-	struct address_space *mapping = inode->i_mapping;
-	struct writeback_control wbc = {
-	       .sync_mode = WB_SYNC_NONE,
-	      .nr_to_write = 0,
-	};
-	/* if we used WB_SYNC_ALL, sync_inode waits for the io for the
-	* inode to finish.  So WB_SYNC_NONE is sent down to sync_inode
+
+	/* if we used wait=1, sync_inode_metadata waits for the io for the
+	* inode to finish.  So wait=0 is sent down to sync_inode_metadata
 	* and filemap_fdatawrite is used for the data blocks
 	*/
-	ret = sync_inode(inode, &wbc);
+	ret = sync_inode_metadata(inode, 0);
 	if (!ret)
-	       ret = filemap_fdatawrite(mapping);
+		ret = filemap_fdatawrite(inode->i_mapping);
 	return ret;
 }