From 66d7ac6bdb07fbe69ca6971558a996ac04bbb643 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 25 Sep 2024 23:57:57 -0400 Subject: [PATCH] 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 --- fs/internal.h | 6 ++--- fs/xattr.c | 69 ++++++++++++++++++++++++++++++------------------ io_uring/xattr.c | 41 +++++----------------------- 3 files changed, 54 insertions(+), 62 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index b9f5ac4d39fc..be7c0da3bcec 100644 --- 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 d8f7c766f28a..38bf8cfbd464 100644 --- 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)) @@ -637,6 +637,45 @@ int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, ctx->kvalue, ctx->size, ctx->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 path path; + int error; + +retry: + 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); + mnt_drop_write(path.mnt); + } + path_put(&path); + if (retry_estale(error, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto 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) @@ -649,29 +688,14 @@ static int path_setxattr(const char __user *pathname, .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); - if (error) - goto out; - error = mnt_want_write(path.mnt); - if (!error) { - error = do_setxattr(mnt_idmap(path.mnt), path.dentry, &ctx); - mnt_drop_write(path.mnt); - } - path_put(&path); - if (retry_estale(error, lookup_flags)) { - lookup_flags |= LOOKUP_REVAL; - goto retry; - } - -out: + 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 0b3b871eaa65..2671ad05d63b 100644 --- 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) +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; - 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) -{ - 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; }