ecryptfs: modify write path to encrypt page in writepage

Change the write path to encrypt the data only when the page is written to
disk in ecryptfs_writepage. Previously, ecryptfs encrypts the page in
ecryptfs_write_end which means that if there are multiple write requests to
the same page, ecryptfs ends up re-encrypting that page over and over again.
This patch minimizes the number of encryptions needed.

Signed-off-by: Thieu Le <thieule@chromium.org>
[tyhicks: Changed NULL .drop_inode sop pointer to generic_drop_inode]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 7d1050e254f9..cedc913d11ba 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -273,7 +273,14 @@ static int ecryptfs_release(struct inode *inode, struct file *file)
 static int
 ecryptfs_fsync(struct file *file, int datasync)
 {
-        return vfs_fsync(ecryptfs_file_to_lower(file), datasync);
+        int rc = 0;
+
+        rc = generic_file_fsync(file, datasync);
+        if (rc)
+                goto out;
+        rc = vfs_fsync(ecryptfs_file_to_lower(file), datasync);
+out:
+        return rc;
 }
 
 static int ecryptfs_fasync(int fd, struct file *file, int flag)