replace do_setxattr() with saner helpers.

io_uring setxattr logics duplicates stuff from fs/xattr.c; provide
saner helpers (filename_setxattr() and file_setxattr() resp.) and
use them.

NB: putname(ERR_PTR()) is a no-op

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/internal.h b/fs/internal.h
index b9f5ac4d39fc70fcda67291438cf44993cd5a54f..be7c0da3bcecc1a8ba2cc9fda5061967c57979ab 100644 (file)
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -285,10 +285,10 @@ ssize_t do_getxattr(struct mnt_idmap *idmap,
                    struct dentry *d,
                    struct kernel_xattr_ctx *ctx);
 
+int file_setxattr(struct file *file, struct kernel_xattr_ctx *ctx);
+int filename_setxattr(int dfd, struct filename *filename,
+                     unsigned int lookup_flags, struct kernel_xattr_ctx *ctx);
 int setxattr_copy(const char __user *name, struct kernel_xattr_ctx *ctx);
-int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
-               struct kernel_xattr_ctx *ctx);
-
 int import_xattr_name(struct xattr_name *kname, const char __user *name);
 
 int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode);

diff --git a/fs/xattr.c b/fs/xattr.c
index d8f7c766f28a4b1ac1b2264ce0ae932282383525..38bf8cfbd46499d38976ac1fc75ab3ae104ca2bc 100644 (file)
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -626,7 +626,7 @@ int setxattr_copy(const char __user *name, struct kernel_xattr_ctx *ctx)
        return error;
 }
 
-int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
+static int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
                struct kernel_xattr_ctx *ctx)
 {
        if (is_posix_acl_xattr(ctx->kname->name))
@@ -637,32 +637,32 @@ int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
                        ctx->kvalue, ctx->size, ctx->flags);
 }
 
-static int path_setxattr(const char __user *pathname,
-                        const char __user *name, const void __user *value,
-                        size_t size, int flags, unsigned int lookup_flags)
+int file_setxattr(struct file *f, struct kernel_xattr_ctx *ctx)
+{
+       int error = mnt_want_write_file(f);
+
+       if (!error) {
+               audit_file(f);
+               error = do_setxattr(file_mnt_idmap(f), f->f_path.dentry, ctx);
+               mnt_drop_write_file(f);
+       }
+       return error;
+}
+
+/* unconditionally consumes filename */
+int filename_setxattr(int dfd, struct filename *filename,
+                     unsigned int lookup_flags, struct kernel_xattr_ctx *ctx)
 {
-       struct xattr_name kname;
-       struct kernel_xattr_ctx ctx = {
-               .cvalue   = value,
-               .kvalue   = NULL,
-               .size     = size,
-               .kname    = &kname,
-               .flags    = flags,
-       };
        struct path path;
        int error;
 
-       error = setxattr_copy(name, &ctx);
-       if (error)
-               return error;
-
 retry:
-       error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
+       error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
        if (error)
                goto out;
        error = mnt_want_write(path.mnt);
        if (!error) {
-               error = do_setxattr(mnt_idmap(path.mnt), path.dentry, &ctx);
+               error = do_setxattr(mnt_idmap(path.mnt), path.dentry, ctx);
                mnt_drop_write(path.mnt);
        }
        path_put(&path);
@@ -672,6 +672,30 @@ retry:
        }
 
 out:
+       putname(filename);
+       return error;
+}
+
+static int path_setxattr(const char __user *pathname,
+                        const char __user *name, const void __user *value,
+                        size_t size, int flags, unsigned int lookup_flags)
+{
+       struct xattr_name kname;
+       struct kernel_xattr_ctx ctx = {
+               .cvalue   = value,
+               .kvalue   = NULL,
+               .size     = size,
+               .kname    = &kname,
+               .flags    = flags,
+       };
+       int error;
+
+       error = setxattr_copy(name, &ctx);
+       if (error)
+               return error;
+
+       error = filename_setxattr(AT_FDCWD, getname(pathname), lookup_flags,
+                                 &ctx);
        kvfree(ctx.kvalue);
        return error;
 }
@@ -707,17 +731,12 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
 
        if (fd_empty(f))
                return -EBADF;
-       audit_file(fd_file(f));
+
        error = setxattr_copy(name, &ctx);
        if (error)
                return error;
 
-       error = mnt_want_write_file(fd_file(f));
-       if (!error) {
-               error = do_setxattr(file_mnt_idmap(fd_file(f)),
-                                   fd_file(f)->f_path.dentry, &ctx);
-               mnt_drop_write_file(fd_file(f));
-       }
+       error = file_setxattr(fd_file(f), &ctx);
        kvfree(ctx.kvalue);
        return error;
 }

diff --git a/io_uring/xattr.c b/io_uring/xattr.c
index 0b3b871eaa65b3c6f5864d0914841be4ad95400f..2671ad05d63b20023a2eb0609f0fb528568fc856 100644 (file)
--- a/io_uring/xattr.c
+++ b/io_uring/xattr.c
@@ -187,12 +187,10 @@ int io_setxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        path = u64_to_user_ptr(READ_ONCE(sqe->addr3));
 
        ix->filename = getname(path);
-       if (IS_ERR(ix->filename)) {
-               ret = PTR_ERR(ix->filename);
-               ix->filename = NULL;
-       }
+       if (IS_ERR(ix->filename))
+               return PTR_ERR(ix->filename);
 
-       return ret;
+       return 0;
 }
 
 int io_fsetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
@@ -200,28 +198,14 @@ int io_fsetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        return __io_setxattr_prep(req, sqe);
 }
 
-static int __io_setxattr(struct io_kiocb *req, unsigned int issue_flags,
-                       const struct path *path)
-{
-       struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
-       int ret;
-
-       ret = mnt_want_write(path->mnt);
-       if (!ret) {
-               ret = do_setxattr(mnt_idmap(path->mnt), path->dentry, &ix->ctx);
-               mnt_drop_write(path->mnt);
-       }
-
-       return ret;
-}
-
 int io_fsetxattr(struct io_kiocb *req, unsigned int issue_flags)
 {
+       struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
        int ret;
 
        WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
 
-       ret = __io_setxattr(req, issue_flags, &req->file->f_path);
+       ret = file_setxattr(req->file, &ix->ctx);
        io_xattr_finish(req, ret);
        return IOU_OK;
 }
@@ -229,23 +213,12 @@ int io_fsetxattr(struct io_kiocb *req, unsigned int issue_flags)
 int io_setxattr(struct io_kiocb *req, unsigned int issue_flags)
 {
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
-       unsigned int lookup_flags = LOOKUP_FOLLOW;
-       struct path path;
        int ret;
 
        WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
 
-retry:
-       ret = filename_lookup(AT_FDCWD, ix->filename, lookup_flags, &path, NULL);
-       if (!ret) {
-               ret = __io_setxattr(req, issue_flags, &path);
-               path_put(&path);
-               if (retry_estale(ret, lookup_flags)) {
-                       lookup_flags |= LOOKUP_REVAL;
-                       goto retry;
-               }
-       }
-
+       ret = filename_setxattr(AT_FDCWD, ix->filename, LOOKUP_FOLLOW, &ix->ctx);
+       ix->filename = NULL;
        io_xattr_finish(req, ret);
        return IOU_OK;
 }