Commit f4bb2981 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: add ext4_iget_normal() which is to be used for dir tree lookups 



If there is a corrupted file system which has directory entries that
point at reserved, metadata inodes, prohibit them from being used by
treating them the same way we treat Boot Loader inodes --- that is,
mark them to be bad inodes.  This prohibits them from being opened,
deleted, or modified via chmod, chown, utimes, etc.

In particular, this prevents a corrupted file system which has a
directory entry which points at the journal inode from being deleted
and its blocks released, after which point Much Hilarity Ensues.

Reported-by: default avatarSami Liedes <sami.liedes@iki.fi>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
parent e2bfb088

fs/ext4/ext4.h

+1 −0
Original line number Diff line number Diff line
@@ -2109,6 +2109,7 @@ int do_journal_get_write_access(handle_t *handle, 
#define CONVERT_INLINE_DATA	 2



extern struct inode *ext4_iget(struct super_block *, unsigned long);

extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);

extern int  ext4_write_inode(struct inode *, struct writeback_control *);

extern int  ext4_setattr(struct dentry *, struct iattr *);

extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,

fs/ext4/inode.c

+7 −0
Original line number Diff line number Diff line
@@ -4104,6 +4104,13 @@ bad_inode: 
	return ERR_PTR(ret);

}



struct inode *ext4_iget_normal(struct super_block *sb, unsigned long ino)

{

	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)

		return ERR_PTR(-EIO);

	return ext4_iget(sb, ino);

}



static int ext4_inode_blocks_set(handle_t *handle,

				struct ext4_inode *raw_inode,

				struct ext4_inode_info *ei)

fs/ext4/namei.c

+2 −2
Original line number Diff line number Diff line
@@ -1417,7 +1417,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi 
					 dentry);

			return ERR_PTR(-EIO);

		}

		inode = ext4_iget(dir->i_sb, ino);

		inode = ext4_iget_normal(dir->i_sb, ino);

		if (inode == ERR_PTR(-ESTALE)) {

			EXT4_ERROR_INODE(dir,

					 "deleted inode referenced: %u",
@@ -1450,7 +1450,7 @@ struct dentry *ext4_get_parent(struct dentry *child) 
		return ERR_PTR(-EIO);

	}



	return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));

	return d_obtain_alias(ext4_iget_normal(child->d_inode->i_sb, ino));

}



/*

fs/ext4/super.c

+1 −1
Original line number Diff line number Diff line
@@ -1001,7 +1001,7 @@ static struct inode *ext4_nfs_get_inode(struct super_block *sb, 
	 * Currently we don't know the generation for parent directory, so

	 * a generation of 0 means "accept any"

	 */

	inode = ext4_iget(sb, ino);

	inode = ext4_iget_normal(sb, ino);

	if (IS_ERR(inode))

		return ERR_CAST(inode);

	if (generation && inode->i_generation != generation) {

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