eCryptfs: fix dentry handling on create error, unlink, and inode destroy (caeeeecf) · Commits · 戴 / test

This patch corrects some erroneous dentry handling in eCryptfs. If there is a problem creating the lower file, then there is nothing that the persistent lower file can do to really help us. This patch makes a vfs_create() failure in the lower filesystem always lead to an unconditional do_create failure in eCryptfs. Under certain sequences of operations, the eCryptfs dentry can remain in the dcache after an unlink. This patch calls d_drop() on the eCryptfs dentry to correct this. eCryptfs has no business calling d_delete() directly on a lower filesystem's dentry. This patch removes the call to d_delete() on the lower persistent file's dentry in ecryptfs_destroy_inode(). (Thanks to David Kleikamp, Eric Sandeen, and Jeff Moyer for helping identify and resolve this issue) Signed-off-by:

Michael Halcrow <mhalcrow@us.ibm.com> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Eric Sandeen <sandeen@redhat.com> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/ecryptfs/inode.c

+4 −16

Original line number	Diff line number	Diff line
		@@ -120,23 +120,10 @@ ecryptfs_do_create(struct inode *directory_inode,
		rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
		ecryptfs_dentry, mode, nd);
		if (rc) {
		struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
		struct ecryptfs_inode_info *inode_info =
		ecryptfs_inode_to_private(ecryptfs_inode);

		printk(KERN_WARNING "%s: Error creating underlying file; "
		"rc = [%d]; checking for existing\n", __FUNCTION__, rc);
		if (inode_info) {
		mutex_lock(&inode_info->lower_file_mutex);
		if (!inode_info->lower_file) {
		mutex_unlock(&inode_info->lower_file_mutex);
		printk(KERN_ERR "%s: Failure to set underlying "
		"file; rc = [%d]\n", __FUNCTION__, rc);
		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
		"rc = [%d]\n", __FUNCTION__, rc);
		goto out_lock;
		}
		mutex_unlock(&inode_info->lower_file_mutex);
		}
		}
		rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
		directory_inode->i_sb, 0);
		if (rc) {
		@@ -451,6 +438,7 @@ static int ecryptfs_unlink(struct inode dir, struct dentry dentry)
		dentry->d_inode->i_nlink =
		ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
		dentry->d_inode->i_ctime = dir->i_ctime;
		d_drop(dentry);
		out_unlock:
		unlock_parent(lower_dentry);
		return rc;

fs/ecryptfs/super.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -86,7 +86,6 @@ static void ecryptfs_destroy_inode(struct inode *inode)
		fput(inode_info->lower_file);
		inode_info->lower_file = NULL;
		d_drop(lower_dentry);
		d_delete(lower_dentry);
		}
		}
		mutex_unlock(&inode_info->lower_file_mutex);

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