linux-kernel - [PATCH 08/32] Unionfs: cache-coherency

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Date:	Sun,  2 Sep 2007 22:20:31 -0400
From:	"Josef 'Jeff' Sipek" <jsipek@...sunysb.edu>
To:	akpm@...ux-foundation.org
Cc:	linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
	hch@...radead.org, viro@....linux.org.uk,
	bharata@...ux.vnet.ibm.com, j.blunck@...harburg.de,
	Erez Zadok <ezk@...sunysb.edu>,
	"Josef 'Jeff' Sipek" <jsipek@...sunysb.edu>
Subject: [PATCH 08/32] Unionfs: cache-coherency - update inode times

From: Erez Zadok <ezk@...sunysb.edu>

Part of cache-coherency support (as per OLS'07 talk and
Documentation/filesystems/unionfs/concepts.txt): update our inode time if
lower had changed.

Signed-off-by: Erez Zadok <ezk@...sunysb.edu>
Signed-off-by: Josef 'Jeff' Sipek <jsipek@...sunysb.edu>
---
 fs/unionfs/file.c   |    7 +++++--
 fs/unionfs/inode.c  |   11 +++++++++++
 fs/unionfs/unlink.c |    3 +++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/fs/unionfs/file.c b/fs/unionfs/file.c
index ad6821c..47b63f3 100644
--- a/fs/unionfs/file.c
+++ b/fs/unionfs/file.c
@@ -67,17 +67,20 @@ out:
 	unionfs_read_unlock(file->f_path.dentry->d_sb);
 	return err;
 }
-static ssize_t unionfs_write(struct file * file, const char __user * buf,
+
+static ssize_t unionfs_write(struct file *file, const char __user *buf,
 			     size_t count, loff_t *ppos)
 {
 	int err = 0;
 
 	unionfs_read_lock(file->f_path.dentry->d_sb);
-
 	if ((err = unionfs_file_revalidate(file, 1)))
 		goto out;
 
 	err = do_sync_write(file, buf, count, ppos);
+	/* update our inode times upon a successful lower write */
+	if (err >= 0)
+		unionfs_copy_attr_times(file->f_path.dentry->d_inode);
 
 out:
 	unionfs_read_unlock(file->f_path.dentry->d_sb);
diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index 9261bed..66614e3 100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -245,6 +245,12 @@ static struct dentry *unionfs_lookup(struct inode *parent,
 		nd->dentry = path_save.dentry;
 		nd->mnt = path_save.mnt;
 	}
+	if (!IS_ERR(ret)) {
+		if (ret)
+			dentry = ret;
+		/* parent times may have changed */
+		unionfs_copy_attr_times(dentry->d_parent->d_inode);
+	}
 
 	unionfs_read_unlock(dentry->d_sb);
 
@@ -675,8 +681,11 @@ out:
 
 	kfree(name);
 
+	if (!err)
+		unionfs_copy_attr_times(dentry->d_inode);
 	unionfs_unlock_dentry(dentry);
 	unionfs_read_unlock(dentry->d_sb);
+
 	return err;
 }
 
@@ -1006,6 +1015,8 @@ static int unionfs_permission(struct inode *inode, int mask,
 			break;
 		}
 	}
+	/* sync times which may have changed (asynchronously) below */
+	unionfs_copy_attr_times(inode);
 
 out:
 	return err;
diff --git a/fs/unionfs/unlink.c b/fs/unionfs/unlink.c
index 822bffe..7ad19ec 100644
--- a/fs/unionfs/unlink.c
+++ b/fs/unionfs/unlink.c
@@ -41,6 +41,9 @@ static int unionfs_unlink_whiteout(struct inode *dir, struct dentry *dentry)
 	dget(lower_dentry);
 	if (!(err = is_robranch_super(dentry->d_sb, bindex)))
 		err = vfs_unlink(lower_dir_dentry->d_inode, lower_dentry);
+	/* if vfs_unlink succeeded, update our inode's times */
+	if (!err)
+		unionfs_copy_attr_times(dentry->d_inode);
 	dput(lower_dentry);
 	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
 	unlock_dir(lower_dir_dentry);
-- 
1.5.2.2.238.g7cbf2f2

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