vfs: check i_nlink limits in vfs_{mkdir,rename_dir,link}

New field of struct super_block - ->s_max_links.  Maximal allowed
value of ->i_nlink or 0; in the latter case all checks still need
to be done in ->link/->mkdir/->rename instances.  Note that this
limit applies both to directoris and to non-directories.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 1 insertions, 13 deletions

diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 5f7c160ea64..07c91ca6017 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -220,12 +220,6 @@ static int jfs_mkdir(struct inode *dip, struct dentry *dentry, umode_t mode)
 
         dquot_initialize(dip);
 
-        /* link count overflow on parent directory ? */
-        if (dip->i_nlink == JFS_LINK_MAX) {
-                rc = -EMLINK;
-                goto out1;
-        }
-
         /*
          * search parent directory for entry/freespace
          * (dtSearch() returns parent directory page pinned)
@@ -806,9 +800,6 @@ static int jfs_link(struct dentry *old_dentry,
         jfs_info("jfs_link: %s %s", old_dentry->d_name.name,
                  dentry->d_name.name);
 
-        if (ip->i_nlink == JFS_LINK_MAX)
-                return -EMLINK;
-
         dquot_initialize(dir);
 
         tid = txBegin(ip->i_sb, 0);
@@ -1138,10 +1129,6 @@ static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
                                 rc = -ENOTEMPTY;
                                 goto out3;
                         }
-                } else if ((new_dir != old_dir) &&
-                           (new_dir->i_nlink == JFS_LINK_MAX)) {
-                        rc = -EMLINK;
-                        goto out3;
                 }
         } else if (new_ip) {
                 IWRITE_LOCK(new_ip, RDWRLOCK_NORMAL);
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 682bca642f3..4661ad70513 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -441,6 +441,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
                 return -ENOMEM;
 
         sb->s_fs_info = sbi;
+        sb->s_max_links = JFS_LINK_MAX;
         sbi->sb = sb;
         sbi->uid = sbi->gid = sbi->umask = -1;