Before, we used to copyup on an open(2) call which used flags implying
writing (O_RDWR, O_WRONLY, O_APPEND). This meant that a file being opened
for writing, then immediately closed (without actually writing to the file),
will still have been copied up. Now, we don't copyup such files in ->open,
but defer the copyup till later. [Bug #591].
Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx>
---
fs/unionfs/commonfops.c | 4 ++--
fs/unionfs/file.c | 1 +
fs/unionfs/union.h | 1 +
3 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/unionfs/commonfops.c b/fs/unionfs/commonfops.c
index 83034c2..b7d3e38 100644
--- a/fs/unionfs/commonfops.c
+++ b/fs/unionfs/commonfops.c
@@ -635,7 +635,7 @@ int unionfs_file_release(struct inode *inode, struct file *file)
* This is important for open-but-unlinked files, as well as mmap
* support.
*/
- err = unionfs_file_revalidate(file, true);
+ err = unionfs_file_revalidate(file, UNIONFS_F(file)->wrote_to_file);
if (unlikely(err))
goto out;
unionfs_check_file(file);
@@ -819,7 +819,7 @@ int unionfs_flush(struct file *file, fl_owner_t id)
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
- err = unionfs_file_revalidate(file, true);
+ err = unionfs_file_revalidate(file, UNIONFS_F(file)->wrote_to_file);
if (unlikely(err))
goto out;
unionfs_check_file(file);
diff --git a/fs/unionfs/file.c b/fs/unionfs/file.c
index f14b38b..09f594d 100644
--- a/fs/unionfs/file.c
+++ b/fs/unionfs/file.c
@@ -67,6 +67,7 @@ static ssize_t unionfs_write(struct file *file, const char __user *buf,
lower_file->f_path.dentry->d_inode);
fsstack_copy_attr_times(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
+ UNIONFS_F(file)->wrote_to_file = true; /* for delayed copyup */
unionfs_check_file(file);
}
diff --git a/fs/unionfs/union.h b/fs/unionfs/union.h
index 4ca4e76..ab877ee 100644
--- a/fs/unionfs/union.h
+++ b/fs/unionfs/union.h
@@ -91,6 +91,7 @@ struct unionfs_file_info {
struct file **lower_files;
int *saved_branch_ids; /* IDs of branches when file was opened */
struct vm_operations_struct *lower_vm_ops;
+ bool wrote_to_file; /* for delayed copyup */
};
/* unionfs inode data in memory */
--
1.5.2.2
--
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