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authorAmir Goldstein <amir73il@gmail.com>2023-08-16 12:18:15 +0300
committerAmir Goldstein <amir73il@gmail.com>2023-10-31 00:12:57 +0200
commitd08d3b3c2caf6c482703bbc5efaa7b9ae95dea20 (patch)
treef2a2f3a802638ba7c3bb1f283cf6b0c8e764f521 /fs/overlayfs
parentc002728f608183449673818076380124935e6b9b (diff)
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ovl: split ovl_want_write() into two helpers
ovl_get_write_access() gets write access to upper mnt without taking freeze protection on upper sb and ovl_start_write() only takes freeze protection on upper sb. These helpers will be used to breakup the large ovl_want_write() scope during copy up into finer grained freeze protection scopes. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/overlayfs.h4
-rw-r--r--fs/overlayfs/util.c26
2 files changed, 30 insertions, 0 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 9817b2dcb132..a22de83e0a9b 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -398,6 +398,10 @@ static inline bool ovl_open_flags_need_copy_up(int flags)
}
/* util.c */
+int ovl_get_write_access(struct dentry *dentry);
+void ovl_put_write_access(struct dentry *dentry);
+void ovl_start_write(struct dentry *dentry);
+void ovl_end_write(struct dentry *dentry);
int ovl_want_write(struct dentry *dentry);
void ovl_drop_write(struct dentry *dentry);
struct dentry *ovl_workdir(struct dentry *dentry);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 4a9e7efc90aa..80f20ca85344 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -17,12 +17,38 @@
#include <linux/ratelimit.h>
#include "overlayfs.h"
+/* Get write access to upper mnt - may fail if upper sb was remounted ro */
+int ovl_get_write_access(struct dentry *dentry)
+{
+ struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
+ return mnt_get_write_access(ovl_upper_mnt(ofs));
+}
+
+/* Get write access to upper sb - may block if upper sb is frozen */
+void ovl_start_write(struct dentry *dentry)
+{
+ struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
+ sb_start_write(ovl_upper_mnt(ofs)->mnt_sb);
+}
+
int ovl_want_write(struct dentry *dentry)
{
struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
return mnt_want_write(ovl_upper_mnt(ofs));
}
+void ovl_put_write_access(struct dentry *dentry)
+{
+ struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
+ mnt_put_write_access(ovl_upper_mnt(ofs));
+}
+
+void ovl_end_write(struct dentry *dentry)
+{
+ struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
+ sb_end_write(ovl_upper_mnt(ofs)->mnt_sb);
+}
+
void ovl_drop_write(struct dentry *dentry)
{
struct ovl_fs *ofs = OVL_FS(dentry->d_sb);