On Fri, 2025-02-21 at 10:36 +1100, NeilBrown wrote:
> fuse already uses d_splice_alias() to ensure an appropriate dentry is
> found for a newly created dentry. Now that ->mkdir can return that
> dentry we do so.
>
> This requires changing create_new_entry() to return a dentry and
> handling that change in all callers.
>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
> ---
> fs/fuse/dir.c | 55 +++++++++++++++++++++++++++++++--------------------
> 1 file changed, 34 insertions(+), 21 deletions(-)
>
> diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
> index 5bb65f38bfb8..8c44c9c73c38 100644
> --- a/fs/fuse/dir.c
> +++ b/fs/fuse/dir.c
> @@ -781,9 +781,9 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
> /*
> * Code shared between mknod, mkdir, symlink and link
> */
> -static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,
> - struct fuse_args *args, struct inode *dir,
> - struct dentry *entry, umode_t mode)
> +static struct dentry *create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,
> + struct fuse_args *args, struct inode *dir,
> + struct dentry *entry, umode_t mode)
> {
> struct fuse_entry_out outarg;
> struct inode *inode;
> @@ -792,11 +792,11 @@ static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,
> struct fuse_forget_link *forget;
>
> if (fuse_is_bad(dir))
> - return -EIO;
> + return ERR_PTR(-EIO);
>
> forget = fuse_alloc_forget();
> if (!forget)
> - return -ENOMEM;
> + return ERR_PTR(-ENOMEM);
>
> memset(&outarg, 0, sizeof(outarg));
> args->nodeid = get_node_id(dir);
> @@ -826,29 +826,27 @@ static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,
> &outarg.attr, ATTR_TIMEOUT(&outarg), 0, 0);
> if (!inode) {
> fuse_queue_forget(fm->fc, forget, outarg.nodeid, 1);
> - return -ENOMEM;
> + return ERR_PTR(-ENOMEM);
> }
> kfree(forget);
>
> d_drop(entry);
> d = d_splice_alias(inode, entry);
> if (IS_ERR(d))
> - return PTR_ERR(d);
> + return d;
>
> - if (d) {
> + if (d)
> fuse_change_entry_timeout(d, &outarg);
> - dput(d);
> - } else {
> + else
> fuse_change_entry_timeout(entry, &outarg);
> - }
> fuse_dir_changed(dir);
> - return 0;
> + return d;
>
> out_put_forget_req:
> if (err == -EEXIST)
> fuse_invalidate_entry(entry);
> kfree(forget);
> - return err;
> + return ERR_PTR(err);
> }
>
> static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
> @@ -856,6 +854,7 @@ static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
> {
> struct fuse_mknod_in inarg;
> struct fuse_mount *fm = get_fuse_mount(dir);
> + struct dentry *de;
> FUSE_ARGS(args);
>
> if (!fm->fc->dont_mask)
> @@ -871,7 +870,12 @@ static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
> args.in_args[0].value = &inarg;
> args.in_args[1].size = entry->d_name.len + 1;
> args.in_args[1].value = entry->d_name.name;
> - return create_new_entry(idmap, fm, &args, dir, entry, mode);
> + de = create_new_entry(idmap, fm, &args, dir, entry, mode);
> + if (IS_ERR(de))
> + return PTR_ERR(de);
> + if (de)
> + dput(de);
> + return 0;
> }
>
> static int fuse_create(struct mnt_idmap *idmap, struct inode *dir,
> @@ -917,7 +921,7 @@ static struct dentry *fuse_mkdir(struct mnt_idmap *idmap, struct inode *dir,
> args.in_args[0].value = &inarg;
> args.in_args[1].size = entry->d_name.len + 1;
> args.in_args[1].value = entry->d_name.name;
> - return ERR_PTR(create_new_entry(idmap, fm, &args, dir, entry, S_IFDIR));
> + return create_new_entry(idmap, fm, &args, dir, entry, S_IFDIR);
> }
>
> static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
> @@ -925,6 +929,7 @@ static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
> {
> struct fuse_mount *fm = get_fuse_mount(dir);
> unsigned len = strlen(link) + 1;
> + struct dentry *de;
> FUSE_ARGS(args);
>
> args.opcode = FUSE_SYMLINK;
> @@ -934,7 +939,12 @@ static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
> args.in_args[1].value = entry->d_name.name;
> args.in_args[2].size = len;
> args.in_args[2].value = link;
> - return create_new_entry(idmap, fm, &args, dir, entry, S_IFLNK);
> + de = create_new_entry(idmap, fm, &args, dir, entry, S_IFLNK);
> + if (IS_ERR(de))
> + return PTR_ERR(de);
> + if (de)
> + dput(de);
> + return 0;
> }
>
> void fuse_flush_time_update(struct inode *inode)
> @@ -1117,7 +1127,7 @@ static int fuse_rename2(struct mnt_idmap *idmap, struct inode *olddir,
> static int fuse_link(struct dentry *entry, struct inode *newdir,
> struct dentry *newent)
> {
> - int err;
> + struct dentry *de;
> struct fuse_link_in inarg;
> struct inode *inode = d_inode(entry);
> struct fuse_mount *fm = get_fuse_mount(inode);
> @@ -1131,13 +1141,16 @@ static int fuse_link(struct dentry *entry, struct inode *newdir,
> args.in_args[0].value = &inarg;
> args.in_args[1].size = newent->d_name.len + 1;
> args.in_args[1].value = newent->d_name.name;
> - err = create_new_entry(&invalid_mnt_idmap, fm, &args, newdir, newent, inode->i_mode);
> - if (!err)
> + de = create_new_entry(&invalid_mnt_idmap, fm, &args, newdir, newent, inode->i_mode);
> + if (!IS_ERR(de)) {
> + if (de)
> + dput(de);
> + de = NULL;
> fuse_update_ctime_in_cache(inode);
> - else if (err == -EINTR)
> + } else if (PTR_ERR(de) == -EINTR)
> fuse_invalidate_attr(inode);
>
> - return err;
> + return PTR_ERR(de);
> }
>
> static void fuse_fillattr(struct mnt_idmap *idmap, struct inode *inode,
Pretty straightforward.
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
