1 files changed, 112 insertions, 40 deletions

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index f8f491677a4a..dfce656ddb33 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -18,8 +18,8 @@
 #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>
@@ -341,12 +341,11 @@ 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;
@@ -386,7 +385,7 @@ 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;
@@ -445,12 +444,25 @@ 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;
@@ -470,6 +482,7 @@ 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;
 }
 
@@ -488,10 +501,59 @@ static void fat_evict_inode(struct inode *inode)
 	fat_detach(inode);
 }
 
+static void fat_set_state(struct super_block *sb,
+			unsigned int set, unsigned int force)
+{
+	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;
+	}
+
+	bh = sb_bread(sb, 0);
+	if (bh == NULL) {
+		fat_msg(sb, KERN_ERR, "unable to read boot sector "
+			"to mark fs as dirty");
+		return;
+	}
+
+	b = (struct fat_boot_sector *) bh->b_data;
+
+	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;
+	}
+
+	mark_buffer_dirty(bh);
+	sync_dirty_buffer(bh);
+	brelse(bh);
+}
+
 static void fat_put_super(struct super_block *sb)
 {
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 
+	fat_set_state(sb, 0, 0);
+
 	iput(sbi->fsinfo_inode);
 	iput(sbi->fat_inode);
 
@@ -566,8 +628,18 @@ static void __exit fat_destroy_inodecache(void)
 
 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);
+
+	/* 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;
 }
 
@@ -597,20 +669,6 @@ 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;
@@ -618,7 +676,8 @@ 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;
@@ -628,7 +687,8 @@ 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) {
 		fat_msg(sb, KERN_ERR, "unable to read inode block "
 		       "for updating (i_pos %lld)", i_pos);
@@ -641,8 +701,7 @@ 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
@@ -703,12 +762,6 @@ static const struct super_operations fat_sops = {
 	.show_options	= fat_show_options,
 };
 
-static const struct export_operations fat_export_ops = {
-	.fh_to_dentry	= fat_fh_to_dentry,
-	.fh_to_parent	= fat_fh_to_parent,
-	.get_parent	= fat_get_parent,
-};
-
 static int fat_show_options(struct seq_file *m, struct dentry *root)
 {
 	struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
@@ -756,8 +809,6 @@ static int fat_show_options(struct seq_file *m, struct dentry *root)
 		seq_puts(m, ",usefree");
 	if (opts->quiet)
 		seq_puts(m, ",quiet");
-	if (opts->nfs)
-		seq_puts(m, ",nfs");
 	if (opts->showexec)
 		seq_puts(m, ",showexec");
 	if (opts->sys_immutable)
@@ -791,6 +842,10 @@ static int fat_show_options(struct seq_file *m, struct dentry *root)
 		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");
 
@@ -807,7 +862,7 @@ enum {
 	Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
 	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_err,
+	Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err,
 };
 
 static const match_table_t fat_tokens = {
@@ -837,7 +892,9 @@ static const match_table_t fat_tokens = {
 	{Opt_err_panic, "errors=panic"},
 	{Opt_err_ro, "errors=remount-ro"},
 	{Opt_discard, "discard"},
-	{Opt_nfs, "nfs"},
+	{Opt_nfs_stale_rw, "nfs"},
+	{Opt_nfs_stale_rw, "nfs=stale_rw"},
+	{Opt_nfs_nostale_ro, "nfs=nostale_ro"},
 	{Opt_obsolete, "conv=binary"},
 	{Opt_obsolete, "conv=text"},
 	{Opt_obsolete, "conv=auto"},
@@ -1034,6 +1091,12 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
 		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;
 
 		/* msdos specific */
 		case Opt_dots:
@@ -1092,9 +1155,6 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
 		case Opt_discard:
 			opts->discard = 1;
 			break;
-		case Opt_nfs:
-			opts->nfs = 1;
-			break;
 
 		/* obsolete mount options */
 		case Opt_obsolete:
@@ -1125,6 +1185,10 @@ 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;
 }
@@ -1135,7 +1199,7 @@ 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++;
@@ -1198,6 +1262,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
 	sb->s_magic = MSDOS_SUPER_MAGIC;
 	sb->s_op = &fat_sops;
 	sb->s_export_op = &fat_export_ops;
+	mutex_init(&sbi->nfs_build_inode_lock);
 	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
 			     DEFAULT_RATELIMIT_BURST);
 
@@ -1298,17 +1363,17 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
 	sbi->prev_free = FAT_START_ENT;
 	sb->s_maxbytes = 0xffffffff;
 
-	if (!sbi->fat_length && b->fat32_length) {
+	if (!sbi->fat_length && b->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);
+		sbi->fat_length = le32_to_cpu(b->fat32.length);
+		sbi->root_cluster = le32_to_cpu(b->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 = le16_to_cpu(b->fat32.info_sector);
 		if (sbi->fsinfo_sector == 0)
 			sbi->fsinfo_sector = 1;
 
@@ -1362,6 +1427,12 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
 	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 = b->fat32.state & FAT_STATE_DIRTY;
+	else /* fat 16 or 12 */
+		sbi->dirty = b->fat16.state & FAT_STATE_DIRTY;
+
 	/* check that FAT table does not overflow */
 	fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
 	total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
@@ -1456,6 +1527,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
 					"the device does not support discard");
 	}
 
+	fat_set_state(sb, 1, 0);
 	return 0;
 
 out_invalid: