1 files changed, 45 insertions, 91 deletions

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index fdb2eb0ad09e..9f1bb747d77d 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -96,7 +96,7 @@ void __ecryptfs_printk(const char *fmt, ...)
 }
 
 /**
- * ecryptfs_init_persistent_file
+ * ecryptfs_init_lower_file
  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
  *                   the lower dentry and the lower mount set
  *
@@ -104,109 +104,68 @@ void __ecryptfs_printk(const char *fmt, ...)
  * inode. All I/O operations to the lower inode occur through that
  * file. When the first eCryptfs dentry that interposes with the first
  * lower dentry for that inode is created, this function creates the
- * persistent file struct and associates it with the eCryptfs
- * inode. When the eCryptfs inode is destroyed, the file is closed.
+ * lower file struct and associates it with the eCryptfs
+ * inode. When all eCryptfs files associated with the inode are released, the
+ * file is closed.
  *
- * The persistent file will be opened with read/write permissions, if
+ * The lower file will be opened with read/write permissions, if
  * possible. Otherwise, it is opened read-only.
  *
- * This function does nothing if a lower persistent file is already
+ * This function does nothing if a lower file is already
  * associated with the eCryptfs inode.
  *
  * Returns zero on success; non-zero otherwise
  */
-int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
+static int ecryptfs_init_lower_file(struct dentry *dentry,
+				    struct file **lower_file)
 {
 	const struct cred *cred = current_cred();
-	struct ecryptfs_inode_info *inode_info =
-		ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
-	int rc = 0;
-
-	if (!inode_info->lower_file) {
-		struct dentry *lower_dentry;
-		struct vfsmount *lower_mnt =
-			ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
+	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
+	int rc;
 
-		lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
-		rc = ecryptfs_privileged_open(&inode_info->lower_file,
-					      lower_dentry, lower_mnt, cred);
-		if (rc) {
-			printk(KERN_ERR "Error opening lower persistent file "
-			       "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
-			       "rc = [%d]\n", lower_dentry, lower_mnt, rc);
-			inode_info->lower_file = NULL;
-		}
+	rc = ecryptfs_privileged_open(lower_file, lower_dentry, lower_mnt,
+				      cred);
+	if (rc) {
+		printk(KERN_ERR "Error opening lower file "
+		       "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
+		       "rc = [%d]\n", lower_dentry, lower_mnt, rc);
+		(*lower_file) = NULL;
 	}
 	return rc;
 }
 
-static struct inode *ecryptfs_get_inode(struct inode *lower_inode,
-		       struct super_block *sb)
+int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode)
 {
-	struct inode *inode;
-	int rc = 0;
+	struct ecryptfs_inode_info *inode_info;
+	int count, rc = 0;
 
-	if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
-		rc = -EXDEV;
-		goto out;
-	}
-	if (!igrab(lower_inode)) {
-		rc = -ESTALE;
-		goto out;
-	}
-	inode = iget5_locked(sb, (unsigned long)lower_inode,
-			     ecryptfs_inode_test, ecryptfs_inode_set,
-			     lower_inode);
-	if (!inode) {
-		rc = -EACCES;
-		iput(lower_inode);
-		goto out;
+	inode_info = ecryptfs_inode_to_private(inode);
+	mutex_lock(&inode_info->lower_file_mutex);
+	count = atomic_inc_return(&inode_info->lower_file_count);
+	if (WARN_ON_ONCE(count < 1))
+		rc = -EINVAL;
+	else if (count == 1) {
+		rc = ecryptfs_init_lower_file(dentry,
+					      &inode_info->lower_file);
+		if (rc)
+			atomic_set(&inode_info->lower_file_count, 0);
 	}
-	if (inode->i_state & I_NEW)
-		unlock_new_inode(inode);
-	else
-		iput(lower_inode);
-	if (S_ISLNK(lower_inode->i_mode))
-		inode->i_op = &ecryptfs_symlink_iops;
-	else if (S_ISDIR(lower_inode->i_mode))
-		inode->i_op = &ecryptfs_dir_iops;
-	if (S_ISDIR(lower_inode->i_mode))
-		inode->i_fop = &ecryptfs_dir_fops;
-	if (special_file(lower_inode->i_mode))
-		init_special_inode(inode, lower_inode->i_mode,
-				   lower_inode->i_rdev);
-	fsstack_copy_attr_all(inode, lower_inode);
-	/* This size will be overwritten for real files w/ headers and
-	 * other metadata */
-	fsstack_copy_inode_size(inode, lower_inode);
-	return inode;
-out:
-	return ERR_PTR(rc);
+	mutex_unlock(&inode_info->lower_file_mutex);
+	return rc;
 }
 
-/**
- * ecryptfs_interpose
- * @lower_dentry: Existing dentry in the lower filesystem
- * @dentry: ecryptfs' dentry
- * @sb: ecryptfs's super_block
- * @flags: flags to govern behavior of interpose procedure
- *
- * Interposes upper and lower dentries.
- *
- * Returns zero on success; non-zero otherwise
- */
-int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
-		       struct super_block *sb, u32 flags)
+void ecryptfs_put_lower_file(struct inode *inode)
 {
-	struct inode *lower_inode = lower_dentry->d_inode;
-	struct inode *inode = ecryptfs_get_inode(lower_inode, sb);
-	if (IS_ERR(inode))
-		return PTR_ERR(inode);
-	if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
-		d_add(dentry, inode);
-	else
-		d_instantiate(dentry, inode);
-	return 0;
+	struct ecryptfs_inode_info *inode_info;
+
+	inode_info = ecryptfs_inode_to_private(inode);
+	if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count,
+				      &inode_info->lower_file_mutex)) {
+		fput(inode_info->lower_file);
+		inode_info->lower_file = NULL;
+		mutex_unlock(&inode_info->lower_file_mutex);
+	}
 }
 
 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
@@ -676,13 +635,8 @@ static struct ecryptfs_cache_info {
 		.size = sizeof(struct ecryptfs_sb_info),
 	},
 	{
-		.cache = &ecryptfs_header_cache_1,
-		.name = "ecryptfs_headers_1",
-		.size = PAGE_CACHE_SIZE,
-	},
-	{
-		.cache = &ecryptfs_header_cache_2,
-		.name = "ecryptfs_headers_2",
+		.cache = &ecryptfs_header_cache,
+		.name = "ecryptfs_headers",
 		.size = PAGE_CACHE_SIZE,
 	},
 	{