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 <[email protected]>
This commit is contained in:
Al Viro 2012-02-06 12:45:27 -05:00
commit 8de5277879
26 changed files with 46 additions and 149 deletions

View file

@ -193,9 +193,6 @@ static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
struct nilfs_transaction_info ti;
int err;
if (inode->i_nlink >= NILFS_LINK_MAX)
return -EMLINK;
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
@ -219,9 +216,6 @@ static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
struct nilfs_transaction_info ti;
int err;
if (dir->i_nlink >= NILFS_LINK_MAX)
return -EMLINK;
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
@ -400,11 +394,6 @@ static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
drop_nlink(new_inode);
nilfs_mark_inode_dirty(new_inode);
} else {
if (dir_de) {
err = -EMLINK;
if (new_dir->i_nlink >= NILFS_LINK_MAX)
goto out_dir;
}
err = nilfs_add_link(new_dentry, old_inode);
if (err)
goto out_dir;

View file

@ -1059,6 +1059,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_export_op = &nilfs_export_ops;
sb->s_root = NULL;
sb->s_time_gran = 1;
sb->s_max_links = NILFS_LINK_MAX;
bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
sb->s_bdi = bdi ? : &default_backing_dev_info;