eCryptfs: make open, truncate, and setattr use persistent file

Rather than open a new lower file for every eCryptfs file that is opened,
truncated, or setattr'd, instead use the existing lower persistent file for
the eCryptfs inode.  Change truncate to use read_write.c functions.  Change
ecryptfs_getxattr() to use the common ecryptfs_getxattr_lower() function.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 41 deletions

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index df70bfa176d9..95be9a90c504 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -187,11 +187,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
         /* Private value of ecryptfs_dentry allocated in
          * ecryptfs_lookup() */
         struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
-        struct inode *lower_inode = NULL;
-        struct file *lower_file = NULL;
-        struct vfsmount *lower_mnt;
         struct ecryptfs_file_info *file_info;
-        int lower_flags;
 
         mount_crypt_stat = &ecryptfs_superblock_to_private(
                 ecryptfs_dentry->d_sb)->mount_crypt_stat;
@@ -219,26 +215,12 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
         if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) {
                 ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
                 /* Policy code enabled in future release */
-                crypt_stat->flags |= ECRYPTFS_POLICY_APPLIED;
-                crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
+                crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED
+                                      | ECRYPTFS_ENCRYPTED);
         }
         mutex_unlock(&crypt_stat->cs_mutex);
-        lower_flags = file->f_flags;
-        if ((lower_flags & O_ACCMODE) == O_WRONLY)
-                lower_flags = (lower_flags & O_ACCMODE) | O_RDWR;
-        if (file->f_flags & O_APPEND)
-                lower_flags &= ~O_APPEND;
-        lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
-        /* Corresponding fput() in ecryptfs_release() */
-        rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
-                                      lower_flags);
-        if (rc) {
-                ecryptfs_printk(KERN_ERR, "Error opening lower file\n");
-                goto out_puts;
-        }
-        ecryptfs_set_file_lower(file, lower_file);
-        /* Isn't this check the same as the one in lookup? */
-        lower_inode = lower_dentry->d_inode;
+        ecryptfs_set_file_lower(
+                file, ecryptfs_inode_to_private(inode)->lower_file);
         if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
                 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
                 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
@@ -260,7 +242,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
                                        "and plaintext passthrough mode is not "
                                        "enabled; returning -EIO\n");
                                 mutex_unlock(&crypt_stat->cs_mutex);
-                                goto out_puts;
+                                goto out_free;
                         }
                         rc = 0;
                         crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
@@ -272,11 +254,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
         ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] "
                         "size: [0x%.16x]\n", inode, inode->i_ino,
                         i_size_read(inode));
-        ecryptfs_set_file_lower(file, lower_file);
         goto out;
-out_puts:
-        mntput(lower_mnt);
-        dput(lower_dentry);
+out_free:
         kmem_cache_free(ecryptfs_file_info_cache,
                         ecryptfs_file_to_private(file));
 out:
@@ -296,20 +275,9 @@ static int ecryptfs_flush(struct file *file, fl_owner_t td)
 
 static int ecryptfs_release(struct inode *inode, struct file *file)
 {
-        struct file *lower_file = ecryptfs_file_to_lower(file);
-        struct ecryptfs_file_info *file_info = ecryptfs_file_to_private(file);
-        struct inode *lower_inode = ecryptfs_inode_to_lower(inode);
-        int rc;
-
-        rc = ecryptfs_close_lower_file(lower_file);
-        if (rc) {
-                printk(KERN_ERR "Error closing lower_file\n");
-                goto out;
-        }
-        inode->i_blocks = lower_inode->i_blocks;
-        kmem_cache_free(ecryptfs_file_info_cache, file_info);
-out:
-        return rc;
+        kmem_cache_free(ecryptfs_file_info_cache,
+                        ecryptfs_file_to_private(file));
+        return 0;
 }
 
 static int