Patchwork [2/2] eCryptfs: Call lower ->flush() from ecryptfs_flush()

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Submitter Colin King
Date Sept. 15, 2012, 7:09 p.m.
Message ID <1347736154-5577-3-git-send-email-colin.king@canonical.com>
Download mbox | patch
Permalink /patch/184093/
State New
Headers show

Comments

Colin King - Sept. 15, 2012, 7:09 p.m.
From: Tyler Hicks <tyhicks@canonical.com>

Since eCryptfs only calls fput() on the lower file in
ecryptfs_release(), eCryptfs should call the lower filesystem's
->flush() from ecryptfs_flush().

If the lower filesystem implements ->flush(), then eCryptfs should try
to flush out any dirty pages prior to calling the lower ->flush(). If
the lower filesystem does not implement ->flush(), then eCryptfs has no
need to do anything in ecryptfs_flush() since dirty pages are now
written out to the lower filesystem in ecryptfs_release().

BugLink: https://launchpad.net/bugs/1047261

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
(upstream cherry pick 64e6651dcc10e9d2cc6230208a8e6c2cfd19ae18)
Colin Ian King <colin.king@canonical.com>
---
 fs/ecryptfs/file.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
Brad Figg - Sept. 16, 2012, 6:08 a.m.
On 09/15/2012 12:09 PM, Colin King wrote:
> From: Tyler Hicks <tyhicks@canonical.com>
> 
> Since eCryptfs only calls fput() on the lower file in
> ecryptfs_release(), eCryptfs should call the lower filesystem's
> ->flush() from ecryptfs_flush().
> 
> If the lower filesystem implements ->flush(), then eCryptfs should try
> to flush out any dirty pages prior to calling the lower ->flush(). If
> the lower filesystem does not implement ->flush(), then eCryptfs has no
> need to do anything in ecryptfs_flush() since dirty pages are now
> written out to the lower filesystem in ecryptfs_release().
> 
> BugLink: https://launchpad.net/bugs/1047261
> 
> Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
> (upstream cherry pick 64e6651dcc10e9d2cc6230208a8e6c2cfd19ae18)
> Colin Ian King <colin.king@canonical.com>
> ---
>  fs/ecryptfs/file.c |   10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
> index 44ce5c6..d45ba45 100644
> --- a/fs/ecryptfs/file.c
> +++ b/fs/ecryptfs/file.c
> @@ -275,8 +275,14 @@ out:
>  
>  static int ecryptfs_flush(struct file *file, fl_owner_t td)
>  {
> -	return file->f_mode & FMODE_WRITE
> -	       ? filemap_write_and_wait(file->f_mapping) : 0;
> +	struct file *lower_file = ecryptfs_file_to_lower(file);
> +
> +	if (lower_file->f_op && lower_file->f_op->flush) {
> +		filemap_write_and_wait(file->f_mapping);
> +		return lower_file->f_op->flush(lower_file, td);
> +	}
> +
> +	return 0;
>  }
>  
>  static int ecryptfs_release(struct inode *inode, struct file *file)
>

Patch

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 44ce5c6..d45ba45 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -275,8 +275,14 @@  out:
 
 static int ecryptfs_flush(struct file *file, fl_owner_t td)
 {
-	return file->f_mode & FMODE_WRITE
-	       ? filemap_write_and_wait(file->f_mapping) : 0;
+	struct file *lower_file = ecryptfs_file_to_lower(file);
+
+	if (lower_file->f_op && lower_file->f_op->flush) {
+		filemap_write_and_wait(file->f_mapping);
+		return lower_file->f_op->flush(lower_file, td);
+	}
+
+	return 0;
 }
 
 static int ecryptfs_release(struct inode *inode, struct file *file)