namei: introduce struct renamedata

In order to handle idmapped mounts we will extend the vfs rename helper
to take two new arguments in follow up patches. Since this operations
already takes a bunch of arguments add a simple struct renamedata and
make the current helper use it before we extend it.

Link: https://lore.kernel.org/r/20210121131959.646623-14-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index ecc8ecb..7b987de 100644 (file)
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -412,9 +412,14 @@ try_again:
        if (ret < 0) {
                cachefiles_io_error(cache, "Rename security error %d", ret);
        } else {
+               struct renamedata rd = {
+                       .old_dir        = d_inode(dir),
+                       .old_dentry     = rep,
+                       .new_dir        = d_inode(cache->graveyard),
+                       .new_dentry     = grave,
+               };
                trace_cachefiles_rename(object, rep, grave, why);
-               ret = vfs_rename(d_inode(dir), rep,
-                                d_inode(cache->graveyard), grave, NULL, 0);
+               ret = vfs_rename(&rd);
                if (ret != 0 && ret != -ENOMEM)
                        cachefiles_io_error(cache,
                                            "Rename failed with error %d", ret);

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 385b5e8..ff48abb 100644 (file)
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -590,6 +590,7 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
        struct dentry *lower_new_dir_dentry;
        struct dentry *trap;
        struct inode *target_inode;
+       struct renamedata rd = {};
 
        if (flags)
                return -EINVAL;
@@ -619,9 +620,12 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
                rc = -ENOTEMPTY;
                goto out_lock;
        }
-       rc = vfs_rename(d_inode(lower_old_dir_dentry), lower_old_dentry,
-                       d_inode(lower_new_dir_dentry), lower_new_dentry,
-                       NULL, 0);
+
+       rd.old_dir      = d_inode(lower_old_dir_dentry);
+       rd.old_dentry   = lower_old_dentry;
+       rd.new_dir      = d_inode(lower_new_dir_dentry);
+       rd.new_dentry   = lower_new_dentry;
+       rc = vfs_rename(&rd);
        if (rc)
                goto out_lock;
        if (target_inode)

diff --git a/fs/namei.c b/fs/namei.c
index 93fa7d8..38ab518 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4311,12 +4311,15 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
  *        ->i_mutex on parents, which works but leads to some truly excessive
  *        locking].
  */
-int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
-              struct inode *new_dir, struct dentry *new_dentry,
-              struct inode **delegated_inode, unsigned int flags)
+int vfs_rename(struct renamedata *rd)
 {
        int error;
        struct user_namespace *mnt_userns = &init_user_ns;
+       struct inode *old_dir = rd->old_dir, *new_dir = rd->new_dir;
+       struct dentry *old_dentry = rd->old_dentry;
+       struct dentry *new_dentry = rd->new_dentry;
+       struct inode **delegated_inode = rd->delegated_inode;
+       unsigned int flags = rd->flags;
        bool is_dir = d_is_dir(old_dentry);
        struct inode *source = old_dentry->d_inode;
        struct inode *target = new_dentry->d_inode;
@@ -4442,6 +4445,7 @@ EXPORT_SYMBOL(vfs_rename);
 int do_renameat2(int olddfd, struct filename *from, int newdfd,
                 struct filename *to, unsigned int flags)
 {
+       struct renamedata rd;
        struct dentry *old_dentry, *new_dentry;
        struct dentry *trap;
        struct path old_path, new_path;
@@ -4545,9 +4549,14 @@ retry_deleg:
                                     &new_path, new_dentry, flags);
        if (error)
                goto exit5;
-       error = vfs_rename(old_path.dentry->d_inode, old_dentry,
-                          new_path.dentry->d_inode, new_dentry,
-                          &delegated_inode, flags);
+
+       rd.old_dir         = old_path.dentry->d_inode;
+       rd.old_dentry      = old_dentry;
+       rd.new_dir         = new_path.dentry->d_inode;
+       rd.new_dentry      = new_dentry;
+       rd.delegated_inode = &delegated_inode;
+       rd.flags           = flags;
+       error = vfs_rename(&rd);
 exit5:
        dput(new_dentry);
 exit4:

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 37d8504..f7d83ff 100644 (file)
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1798,7 +1798,13 @@ retry:
                close_cached = true;
                goto out_dput_old;
        } else {
-               host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
+               struct renamedata rd = {
+                       .old_dir        = fdir,
+                       .old_dentry     = odentry,
+                       .new_dir        = tdir,
+                       .new_dentry     = ndentry,
+               };
+               host_err = vfs_rename(&rd);
                if (!host_err) {
                        host_err = commit_metadata(tfhp);
                        if (!host_err)

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 0002834..4268996 100644 (file)
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -214,9 +214,16 @@ static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
                                unsigned int flags)
 {
        int err;
+       struct renamedata rd = {
+               .old_dir        = olddir,
+               .old_dentry     = olddentry,
+               .new_dir        = newdir,
+               .new_dentry     = newdentry,
+               .flags          = flags,
+       };
 
        pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
-       err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
+       err = vfs_rename(&rd);
        if (err) {
                pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
                         olddentry, newdentry, err);

diff --git a/include/linux/fs.h b/include/linux/fs.h
index a27884a..430e457 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1775,7 +1775,17 @@ extern int vfs_symlink(struct inode *, struct dentry *, const char *);
 extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);
 extern int vfs_rmdir(struct inode *, struct dentry *);
 extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
-extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);
+
+struct renamedata {
+       struct inode *old_dir;
+       struct dentry *old_dentry;
+       struct inode *new_dir;
+       struct dentry *new_dentry;
+       struct inode **delegated_inode;
+       unsigned int flags;
+} __randomize_layout;
+
+int vfs_rename(struct renamedata *);
 
 static inline int vfs_whiteout(struct inode *dir, struct dentry *dentry)
 {