ovl: mark upper merge dir with type origin entries "impure"

An upper dir is marked "impure" to let ovl_iterate() know that this
directory may contain non pure upper entries whose d_ino may need to be
read from the origin inode.

We already mark a non-merge dir "impure" when moving a non-pure child
entry inside it, to let ovl_iterate() know not to iterate the non-merge
dir directly.

Mark also a merge dir "impure" when moving a non-pure child entry inside
it and when copying up a child entry inside it.

This can be used to optimize ovl_iterate() to perform a "pure merge" of
upper and lower directories, merging the content of the directories,
without having to read d_ino from origin inodes.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 843ed2a2d7dbc3ba6bebbc526597696b3652b7d5..7a44533f4bbf24134a95bdc030bde5779f28457a 100644 (file)
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -459,6 +459,11 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
        ovl_path_upper(parent, &parentpath);
        upperdir = parentpath.dentry;
 
+       /* Mark parent "impure" because it may now contain non-pure upper */
+       err = ovl_set_impure(parent, upperdir);
+       if (err)
+               return err;
+
        err = vfs_getattr(&parentpath, &pstat,
                          STATX_ATIME | STATX_MTIME, AT_STATX_SYNC_AS_STAT);
        if (err)

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index f2a118ba00e4b890e83ac36b5bb7c0aebba042ef..a63a71656e9bdaef6ed5cadf8acdb6d8002fe1b6 100644 (file)
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -149,22 +149,6 @@ static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)
        return ovl_set_opaque_xerr(dentry, upperdentry, -EIO);
 }
 
-static int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry)
-{
-       int err;
-
-       /*
-        * Do not fail when upper doesn't support xattrs.
-        * Upper inodes won't have origin nor redirect xattr anyway.
-        */
-       err = ovl_check_setxattr(dentry, upperdentry, OVL_XATTR_IMPURE,
-                                "y", 1, 0);
-       if (!err)
-               ovl_dentry_set_impure(dentry);
-
-       return err;
-}
-
 /* Common operations required to be done after creation of file on upper */
 static void ovl_instantiate(struct dentry *dentry, struct inode *inode,
                            struct dentry *newdentry, bool hardlink)
@@ -976,21 +960,16 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
        if (!samedir) {
                /*
                 * When moving a merge dir or non-dir with copy up origin into
-                * a non-merge upper dir (a.k.a pure upper dir), we are making
-                * the target parent dir "impure". ovl_iterate() iterates pure
-                * upper dirs directly, because there is no need to filter out
-                * whiteouts and merge dir content with lower dir. But for the
-                * case of an "impure" upper dir, ovl_iterate() cannot iterate
-                * the real directory directly, because it looks for the inode
-                * numbers to fill d_ino in the entries origin inode.
+                * a new parent, we are marking the new parent dir "impure".
+                * When ovl_iterate() iterates an "impure" upper dir, it will
+                * lookup the origin inodes of the entries to fill d_ino.
                 */
-               if (ovl_type_origin(old) && !ovl_type_merge(new->d_parent)) {
+               if (ovl_type_origin(old)) {
                        err = ovl_set_impure(new->d_parent, new_upperdir);
                        if (err)
                                goto out_revert_creds;
                }
-               if (!overwrite && ovl_type_origin(new) &&
-                   !ovl_type_merge(old->d_parent)) {
+               if (!overwrite && ovl_type_origin(new)) {
                        err = ovl_set_impure(old->d_parent, old_upperdir);
                        if (err)
                                goto out_revert_creds;

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 0c72a5909db28025b70d973eff1bcb14ba3ff24f..f3136c31e72af24cbb9949449a12d292fc3bf11b 100644 (file)
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -167,31 +167,11 @@ invalid:
        goto out;
 }
 
-static bool ovl_check_dir_xattr(struct dentry *dentry, const char *name)
-{
-       int res;
-       char val;
-
-       if (!d_is_dir(dentry))
-               return false;
-
-       res = vfs_getxattr(dentry, name, &val, 1);
-       if (res == 1 && val == 'y')
-               return true;
-
-       return false;
-}
-
 static bool ovl_is_opaquedir(struct dentry *dentry)
 {
        return ovl_check_dir_xattr(dentry, OVL_XATTR_OPAQUE);
 }
 
-static bool ovl_is_impuredir(struct dentry *dentry)
-{
-       return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
-}
-
 static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
                             const char *name, unsigned int namelen,
                             size_t prelen, const char *post,

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index a9fb958fd5d44f0c68b7bc8187fe5290e7bb40eb..0623cebeefff8661d49d65a228ceec6290cee877 100644 (file)
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -207,7 +207,6 @@ bool ovl_dentry_is_opaque(struct dentry *dentry);
 bool ovl_dentry_is_impure(struct dentry *dentry);
 bool ovl_dentry_is_whiteout(struct dentry *dentry);
 void ovl_dentry_set_opaque(struct dentry *dentry);
-void ovl_dentry_set_impure(struct dentry *dentry);
 bool ovl_redirect_dir(struct super_block *sb);
 const char *ovl_dentry_get_redirect(struct dentry *dentry);
 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
@@ -221,6 +220,17 @@ bool ovl_is_whiteout(struct dentry *dentry);
 struct file *ovl_path_open(struct path *path, int flags);
 int ovl_copy_up_start(struct dentry *dentry);
 void ovl_copy_up_end(struct dentry *dentry);
+bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
+int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
+                      const char *name, const void *value, size_t size,
+                      int xerr);
+int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
+
+static inline bool ovl_is_impuredir(struct dentry *dentry)
+{
+       return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
+}
+
 
 /* namei.c */
 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
@@ -281,6 +291,3 @@ int ovl_copy_up(struct dentry *dentry);
 int ovl_copy_up_flags(struct dentry *dentry, int flags);
 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
 int ovl_set_attr(struct dentry *upper, struct kstat *stat);
-int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
-                      const char *name, const void *value, size_t size,
-                      int xerr);

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index f1647626a882f51079207985b1695f2ee898bf4e..4882ffb37baead1c4da41684158d22cbe58e5353 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -974,7 +974,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
        path_put(&workpath);
        kfree(lowertmp);
 
-       oe->__upperdentry = upperpath.dentry;
+       if (upperpath.dentry) {
+               oe->__upperdentry = upperpath.dentry;
+               oe->impure = ovl_is_impuredir(upperpath.dentry);
+       }
        for (i = 0; i < numlower; i++) {
                oe->lowerstack[i].dentry = stack[i].dentry;
                oe->lowerstack[i].mnt = ufs->lower_mnt[i];

diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index e0dfb07d5457f7203165436452c586520f1d6982..809048913889189d083339d1d015ef4cad2af035 100644 (file)
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -194,13 +194,6 @@ void ovl_dentry_set_opaque(struct dentry *dentry)
        oe->opaque = true;
 }
 
-void ovl_dentry_set_impure(struct dentry *dentry)
-{
-       struct ovl_entry *oe = dentry->d_fsdata;
-
-       oe->impure = true;
-}
-
 bool ovl_redirect_dir(struct super_block *sb)
 {
        struct ovl_fs *ofs = sb->s_fs_info;
@@ -311,6 +304,21 @@ void ovl_copy_up_end(struct dentry *dentry)
        spin_unlock(&ofs->copyup_wq.lock);
 }
 
+bool ovl_check_dir_xattr(struct dentry *dentry, const char *name)
+{
+       int res;
+       char val;
+
+       if (!d_is_dir(dentry))
+               return false;
+
+       res = vfs_getxattr(dentry, name, &val, 1);
+       if (res == 1 && val == 'y')
+               return true;
+
+       return false;
+}
+
 int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
                       const char *name, const void *value, size_t size,
                       int xerr)
@@ -331,3 +339,23 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
 
        return err;
 }
+
+int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry)
+{
+       int err;
+       struct ovl_entry *oe = dentry->d_fsdata;
+
+       if (oe->impure)
+               return 0;
+
+       /*
+        * Do not fail when upper doesn't support xattrs.
+        * Upper inodes won't have origin nor redirect xattr anyway.
+        */
+       err = ovl_check_setxattr(dentry, upperdentry, OVL_XATTR_IMPURE,
+                                "y", 1, 0);
+       if (!err)
+               oe->impure = true;
+
+       return err;
+}