eCryptfs: fix dentry handling on create error, unlink, and inode destroy
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>
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 0b1ab01..5a71918 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -120,22 +120,9 @@
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);
- goto out_lock;
- }
- mutex_unlock(&inode_info->lower_file_mutex);
- }
+ printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
+ "rc = [%d]\n", __FUNCTION__, rc);
+ goto out_lock;
}
rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
directory_inode->i_sb, 0);
@@ -451,6 +438,7 @@
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;