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authorVivek Goyal <vgoyal@redhat.com>2018-05-11 18:49:30 +0300
committerMiklos Szeredi <mszeredi@redhat.com>2018-07-20 10:56:10 +0300
commit647d253fcd53fae185408b33ec5587a57cb3cc88 (patch)
tree103c994ef5fb20efc45241e5437f435138f73986 /fs/overlayfs
parent4f93b426ab3930952eca6c5c456c2223a3adcbf5 (diff)
downloadlinux-647d253fcd53fae185408b33ec5587a57cb3cc88.tar.xz
ovl: Add helper ovl_dentry_lowerdata() to get lower data dentry
Now we have the notion of data dentry and metacopy dentry. ovl_dentry_lower() will return uppermost lower dentry, but it could be either data or metacopy dentry. Now we support metacopy dentries in lower layers so it is possible that lowerstack[0] is metacopy dentry while lowerstack[1] is actual data dentry. So add an helper which returns lowest most dentry which is supposed to be data dentry. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/overlayfs.h1
-rw-r--r--fs/overlayfs/util.c13
2 files changed, 14 insertions, 0 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index a59c546c10cf..deda94381aac 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -221,6 +221,7 @@ void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
struct dentry *ovl_dentry_upper(struct dentry *dentry);
struct dentry *ovl_dentry_lower(struct dentry *dentry);
+struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
struct dentry *ovl_dentry_real(struct dentry *dentry);
struct dentry *ovl_i_dentry_upper(struct inode *inode);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 32ff67fa0bfb..7c7b95d5da1f 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -207,6 +207,19 @@ struct ovl_layer *ovl_layer_lower(struct dentry *dentry)
return oe->numlower ? oe->lowerstack[0].layer : NULL;
}
+/*
+ * ovl_dentry_lower() could return either a data dentry or metacopy dentry
+ * dependig on what is stored in lowerstack[0]. At times we need to find
+ * lower dentry which has data (and not metacopy dentry). This helper
+ * returns the lower data dentry.
+ */
+struct dentry *ovl_dentry_lowerdata(struct dentry *dentry)
+{
+ struct ovl_entry *oe = dentry->d_fsdata;
+
+ return oe->numlower ? oe->lowerstack[oe->numlower - 1].dentry : NULL;
+}
+
struct dentry *ovl_dentry_real(struct dentry *dentry)
{
return ovl_dentry_upper(dentry) ?: ovl_dentry_lower(dentry);