Commit caeeeecf authored by Michael Halcrow's avatar Michael Halcrow Committed by Linus Torvalds

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: default avatarMichael 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c51b1a16
...@@ -120,22 +120,9 @@ ecryptfs_do_create(struct inode *directory_inode, ...@@ -120,22 +120,9 @@ ecryptfs_do_create(struct inode *directory_inode,
rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode, rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
ecryptfs_dentry, mode, nd); ecryptfs_dentry, mode, nd);
if (rc) { if (rc) {
struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
struct ecryptfs_inode_info *inode_info = "rc = [%d]\n", __FUNCTION__, rc);
ecryptfs_inode_to_private(ecryptfs_inode); goto out_lock;
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);
}
} }
rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry, rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
directory_inode->i_sb, 0); directory_inode->i_sb, 0);
...@@ -451,6 +438,7 @@ static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry) ...@@ -451,6 +438,7 @@ static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
dentry->d_inode->i_nlink = dentry->d_inode->i_nlink =
ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink; ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
dentry->d_inode->i_ctime = dir->i_ctime; dentry->d_inode->i_ctime = dir->i_ctime;
d_drop(dentry);
out_unlock: out_unlock:
unlock_parent(lower_dentry); unlock_parent(lower_dentry);
return rc; return rc;
......
...@@ -86,7 +86,6 @@ static void ecryptfs_destroy_inode(struct inode *inode) ...@@ -86,7 +86,6 @@ static void ecryptfs_destroy_inode(struct inode *inode)
fput(inode_info->lower_file); fput(inode_info->lower_file);
inode_info->lower_file = NULL; inode_info->lower_file = NULL;
d_drop(lower_dentry); d_drop(lower_dentry);
d_delete(lower_dentry);
} }
} }
mutex_unlock(&inode_info->lower_file_mutex); mutex_unlock(&inode_info->lower_file_mutex);
......
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