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>

1 files changed, 1 insertions, 13 deletions

diff --git a/fs/minix/namei.c b/fs/minix/namei.c
index 2f76e38c2065..2d0ee1786305 100644
--- a/fs/minix/namei.c
+++ b/fs/minix/namei.c
@@ -94,9 +94,6 @@ static int minix_link(struct dentry * old_dentry, struct inode * dir,
 {
         struct inode *inode = old_dentry->d_inode;
 
-        if (inode->i_nlink >= minix_sb(inode->i_sb)->s_link_max)
-                return -EMLINK;
-
         inode->i_ctime = CURRENT_TIME_SEC;
         inode_inc_link_count(inode);
         ihold(inode);
@@ -106,10 +103,7 @@ static int minix_link(struct dentry * old_dentry, struct inode * dir,
 static int minix_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
 {
         struct inode * inode;
-        int err = -EMLINK;
-
-        if (dir->i_nlink >= minix_sb(dir->i_sb)->s_link_max)
-                goto out;
+        int err;
 
         inode_inc_link_count(dir);
 
@@ -181,7 +175,6 @@ static int minix_rmdir(struct inode * dir, struct dentry *dentry)
 static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
                            struct inode * new_dir, struct dentry *new_dentry)
 {
-        struct minix_sb_info * info = minix_sb(old_dir->i_sb);
         struct inode * old_inode = old_dentry->d_inode;
         struct inode * new_inode = new_dentry->d_inode;
         struct page * dir_page = NULL;
@@ -219,11 +212,6 @@ static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
                         drop_nlink(new_inode);
                 inode_dec_link_count(new_inode);
         } else {
-                if (dir_de) {
-                        err = -EMLINK;
-                        if (new_dir->i_nlink >= info->s_link_max)
-                                goto out_dir;
-                }
                 err = minix_add_link(new_dentry, old_inode);
                 if (err)
                         goto out_dir;