1 files changed, 40 insertions, 34 deletions

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index acf6e479b443..4ff901632b26 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -18,7 +18,6 @@
 #include <linux/pagemap.h>
 #include <linux/mpage.h>
 #include <linux/buffer_head.h>
-#include <linux/exportfs.h>
 #include <linux/mount.h>
 #include <linux/vfs.h>
 #include <linux/parser.h>
@@ -385,7 +384,7 @@ 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;
@@ -444,12 +443,25 @@ 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;
@@ -469,6 +481,7 @@ 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;
 }
 
@@ -655,20 +668,6 @@ 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;
@@ -676,7 +675,8 @@ 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;
@@ -686,7 +686,8 @@ 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);
@@ -699,8 +700,7 @@ 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
@@ -761,12 +761,6 @@ 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);
@@ -814,8 +808,6 @@ 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)
@@ -849,6 +841,10 @@ 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");
 
@@ -865,7 +861,7 @@ 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 = {
@@ -895,7 +891,9 @@ 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"},
@@ -1092,6 +1090,12 @@ 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:
@@ -1150,9 +1154,6 @@ 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:
@@ -1183,6 +1184,10 @@ 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;
 }
@@ -1193,7 +1198,7 @@ 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++;
@@ -1256,6 +1261,7 @@ 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);