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-rw-r--r--fs/ecryptfs/main.c72
1 files changed, 50 insertions, 22 deletions
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index fdb2eb0..89b9338 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
*
@@ -104,42 +104,70 @@ 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;
+ struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
+ int rc;
- if (!inode_info->lower_file) {
- struct dentry *lower_dentry;
- struct vfsmount *lower_mnt =
- ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
+ 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;
+}
- 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;
- }
+int ecryptfs_get_lower_file(struct dentry *dentry)
+{
+ struct ecryptfs_inode_info *inode_info =
+ ecryptfs_inode_to_private(dentry->d_inode);
+ int count, rc = 0;
+
+ 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);
}
+ mutex_unlock(&inode_info->lower_file_mutex);
return rc;
}
+void ecryptfs_put_lower_file(struct inode *inode)
+{
+ 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);
+ }
+}
+
static struct inode *ecryptfs_get_inode(struct inode *lower_inode,
struct super_block *sb)
{
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