The helper determines which lower file needs to be indexed
on copy up and before nlink changes.
For index=on, the helper evaluates to true for lower hardlinks.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/overlayfs/copy_up.c | 6 +-----
fs/overlayfs/overlayfs.h | 1 +
fs/overlayfs/util.c | 25 +++++++++++++++++++++----
3 files changed, 23 insertions(+), 9 deletions(-)
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index c441f9387a1b..6729ea2a5a1c 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -532,11 +532,7 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c)
{
int err;
struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info;
- bool indexed = false;
-
- if (ovl_indexdir(c->dentry->d_sb) && !S_ISDIR(c->stat.mode) &&
- c->stat.nlink > 1)
- indexed = true;
+ bool indexed = ovl_need_index(c->dentry);
if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || indexed)
c->origin = true;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index df605368700d..17457483ccf6 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -235,6 +235,7 @@ void ovl_clear_flag(unsigned long flag, struct inode *inode);
bool ovl_test_flag(unsigned long flag, struct inode *inode);
bool ovl_inuse_trylock(struct dentry *dentry);
void ovl_inuse_unlock(struct dentry *dentry);
+bool ovl_need_index(struct dentry *dentry);
int ovl_nlink_start(struct dentry *dentry, bool *locked);
void ovl_nlink_end(struct dentry *dentry, bool locked);
int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 7355c51ae05f..6b3af32ab0e9 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -506,6 +506,24 @@ static void ovl_cleanup_index(struct dentry *dentry)
}
/*
+ * Does this overlay dentry need to be indexed on copy up?
+ */
+bool ovl_need_index(struct dentry *dentry)
+{
+ struct dentry *lower = ovl_dentry_lower(dentry);
+
+ if (!lower)
+ return false;
+
+ /* Index only lower hardlinks on copy up */
+ if (ovl_indexdir(dentry->d_sb) &&
+ !d_is_dir(lower) && d_inode(lower)->i_nlink > 1)
+ return true;
+
+ return false;
+}
+
+/*
* Operations that change overlay inode and upper inode nlink need to be
* synchronized with copy up for persistent nlink accounting.
*/
@@ -520,11 +538,11 @@ int ovl_nlink_start(struct dentry *dentry, bool *locked)
/*
* With inodes index is enabled, we store the union overlay nlink
- * in an xattr on the index inode. When whiting out lower hardlinks
+ * in an xattr on the index inode. When whiting out an indexed lower,
* we need to decrement the overlay persistent nlink, but before the
* first copy up, we have no upper index inode to store the xattr.
*
- * As a workaround, before whiteout/rename over of a lower hardlink,
+ * As a workaround, before whiteout/rename over an indexed lower,
* copy up to create the upper index. Creating the upper index will
* initialize the overlay nlink, so it could be dropped if unlink
* or rename succeeds.
@@ -532,8 +550,7 @@ int ovl_nlink_start(struct dentry *dentry, bool *locked)
* TODO: implement metadata only index copy up when called with
* ovl_copy_up_flags(dentry, O_PATH).
*/
- if (ovl_indexdir(dentry->d_sb) && !ovl_dentry_has_upper_alias(dentry) &&
- d_inode(ovl_dentry_lower(dentry))->i_nlink > 1) {
+ if (ovl_need_index(dentry) && !ovl_dentry_has_upper_alias(dentry)) {
err = ovl_copy_up(dentry);
if (err)
return err;
--
2.7.4
--
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