fuse: add renameat2 support

Support RENAME_EXCHANGE and RENAME_NOREPLACE flags on the userspace ABI.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

3 files changed, 58 insertions, 8 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 843dcf1222eb..42198359fa1b 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -752,23 +752,26 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry)
         return err;
 }
 
-static int fuse_rename(struct inode *olddir, struct dentry *oldent,
-                       struct inode *newdir, struct dentry *newent)
+static int fuse_rename_common(struct inode *olddir, struct dentry *oldent,
+                              struct inode *newdir, struct dentry *newent,
+                              unsigned int flags, int opcode, size_t argsize)
 {
         int err;
-        struct fuse_rename_in inarg;
+        struct fuse_rename2_in inarg;
         struct fuse_conn *fc = get_fuse_conn(olddir);
-        struct fuse_req *req = fuse_get_req_nopages(fc);
+        struct fuse_req *req;
 
+        req = fuse_get_req_nopages(fc);
         if (IS_ERR(req))
                 return PTR_ERR(req);
 
-        memset(&inarg, 0, sizeof(inarg));
+        memset(&inarg, 0, argsize);
         inarg.newdir = get_node_id(newdir);
-        req->in.h.opcode = FUSE_RENAME;
+        inarg.flags = flags;
+        req->in.h.opcode = opcode;
         req->in.h.nodeid = get_node_id(olddir);
         req->in.numargs = 3;
-        req->in.args[0].size = sizeof(inarg);
+        req->in.args[0].size = argsize;
         req->in.args[0].value = &inarg;
         req->in.args[1].size = oldent->d_name.len + 1;
         req->in.args[1].value = oldent->d_name.name;
@@ -782,12 +785,17 @@ static int fuse_rename(struct inode *olddir, struct dentry *oldent,
                 fuse_invalidate_attr(oldent->d_inode);
                 fuse_update_ctime(oldent->d_inode);
 
+                if (flags & RENAME_EXCHANGE) {
+                        fuse_invalidate_attr(newent->d_inode);
+                        fuse_update_ctime(newent->d_inode);
+                }
+
                 fuse_invalidate_attr(olddir);
                 if (olddir != newdir)
                         fuse_invalidate_attr(newdir);
 
                 /* newent will end up negative */
-                if (newent->d_inode) {
+                if (!(flags & RENAME_EXCHANGE) && newent->d_inode) {
                         fuse_invalidate_attr(newent->d_inode);
                         fuse_invalidate_entry_cache(newent);
                         fuse_update_ctime(newent->d_inode);
@@ -806,6 +814,36 @@ static int fuse_rename(struct inode *olddir, struct dentry *oldent,
         return err;
 }
 
+static int fuse_rename(struct inode *olddir, struct dentry *oldent,
+                       struct inode *newdir, struct dentry *newent)
+{
+        return fuse_rename_common(olddir, oldent, newdir, newent, 0,
+                                  FUSE_RENAME, sizeof(struct fuse_rename_in));
+}
+
+static int fuse_rename2(struct inode *olddir, struct dentry *oldent,
+                        struct inode *newdir, struct dentry *newent,
+                        unsigned int flags)
+{
+        struct fuse_conn *fc = get_fuse_conn(olddir);
+        int err;
+
+        if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+                return -EINVAL;
+
+        if (fc->no_rename2 || fc->minor < 23)
+                return -EINVAL;
+
+        err = fuse_rename_common(olddir, oldent, newdir, newent, flags,
+                                 FUSE_RENAME2, sizeof(struct fuse_rename2_in));
+        if (err == -ENOSYS) {
+                fc->no_rename2 = 1;
+                err = -EINVAL;
+        }
+        return err;
+
+}
+
 static int fuse_link(struct dentry *entry, struct inode *newdir,
                      struct dentry *newent)
 {
@@ -1980,6 +2018,7 @@ static const struct inode_operations fuse_dir_inode_operations = {
         .unlink         = fuse_unlink,
         .rmdir          = fuse_rmdir,
         .rename         = fuse_rename,
+        .rename2        = fuse_rename2,
         .link           = fuse_link,
         .setattr        = fuse_setattr,
         .create         = fuse_create,
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 40677e33504f..7aa5c75e0de1 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -542,6 +542,9 @@ struct fuse_conn {
         /** Is fallocate not implemented by fs? */
         unsigned no_fallocate:1;
 
+        /** Is rename with flags implemented by fs? */
+        unsigned no_rename2:1;
+
         /** Use enhanced/automatic page cache invalidation. */
         unsigned auto_inval_data:1;
 
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index e86a21acef75..40b5ca8a1b1f 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -100,6 +100,7 @@
  *  - add reserved space to fuse_init_out
  *  - add FATTR_CTIME
  *  - add ctime and ctimensec to fuse_setattr_in
+ *  - add FUSE_RENAME2 request
  */
 
 #ifndef _LINUX_FUSE_H
@@ -353,6 +354,7 @@ enum fuse_opcode {
         FUSE_BATCH_FORGET  = 42,
         FUSE_FALLOCATE     = 43,
         FUSE_READDIRPLUS   = 44,
+        FUSE_RENAME2       = 45,
 
         /* CUSE specific operations */
         CUSE_INIT          = 4096,
@@ -431,6 +433,12 @@ struct fuse_rename_in {
         uint64_t        newdir;
 };
 
+struct fuse_rename2_in {
+        uint64_t        newdir;
+        uint32_t        flags;
+        uint32_t        padding;
+};
+
 struct fuse_link_in {
         uint64_t        oldnodeid;
 };