fat (exportfs): rebuild directory-inode if fat_dget()

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / fat / nfs.c

diff --git a/fs/fat/nfs.c b/fs/fat/nfs.c
index 0748196889b2591faf50abd922a26fcc330303d1..93e14933dcb6fc2abc24462fe9965a070e6d234d 100644 (file)
--- a/fs/fat/nfs.c
+++ b/fs/fat/nfs.c
@@ -215,6 +215,53 @@ static struct dentry *fat_fh_to_parent_nostale(struct super_block *sb,
        return d_obtain_alias(inode);
 }
 
+/*
+ * Rebuild the parent for a directory that is not connected
+ *  to the filesystem root
+ */
+static
+struct inode *fat_rebuild_parent(struct super_block *sb, int parent_logstart)
+{
+       int search_clus, clus_to_match;
+       struct msdos_dir_entry *de;
+       struct inode *parent = NULL;
+       struct inode *dummy_grand_parent = NULL;
+       struct fat_slot_info sinfo;
+       struct msdos_sb_info *sbi = MSDOS_SB(sb);
+       sector_t blknr = fat_clus_to_blknr(sbi, parent_logstart);
+       struct buffer_head *parent_bh = sb_bread(sb, blknr);
+       if (!parent_bh) {
+               fat_msg(sb, KERN_ERR,
+                       "unable to read cluster of parent directory");
+               return NULL;
+       }
+
+       de = (struct msdos_dir_entry *) parent_bh->b_data;
+       clus_to_match = fat_get_start(sbi, &de[0]);
+       search_clus = fat_get_start(sbi, &de[1]);
+
+       dummy_grand_parent = fat_dget(sb, search_clus);
+       if (!dummy_grand_parent) {
+               dummy_grand_parent = new_inode(sb);
+               if (!dummy_grand_parent) {
+                       brelse(parent_bh);
+                       return parent;
+               }
+
+               dummy_grand_parent->i_ino = iunique(sb, MSDOS_ROOT_INO);
+               fat_fill_inode(dummy_grand_parent, &de[1]);
+               MSDOS_I(dummy_grand_parent)->i_pos = -1;
+       }
+
+       if (!fat_scan_logstart(dummy_grand_parent, clus_to_match, &sinfo))
+               parent = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
+
+       brelse(parent_bh);
+       iput(dummy_grand_parent);
+
+       return parent;
+}
+
 /*
  * Find the parent for a directory that is not currently connected to
  * the filesystem root.
@@ -227,10 +274,13 @@ static struct dentry *fat_get_parent(struct dentry *child_dir)
        struct buffer_head *bh = NULL;
        struct msdos_dir_entry *de;
        struct inode *parent_inode = NULL;
+       struct msdos_sb_info *sbi = MSDOS_SB(sb);
 
        if (!fat_get_dotdot_entry(child_dir->d_inode, &bh, &de)) {
-               int parent_logstart = fat_get_start(MSDOS_SB(sb), de);
+               int parent_logstart = fat_get_start(sbi, de);
                parent_inode = fat_dget(sb, parent_logstart);
+               if (!parent_inode && sbi->options.nfs == FAT_NFS_NOSTALE_RO)
+                       parent_inode = fat_rebuild_parent(sb, parent_logstart);
        }
        brelse(bh);