From 8a86e7b6a67f21294ada5bf67f3484ae3e134848 Mon Sep 17 00:00:00 2001 From: Sergey Bugaev Date: Sun, 12 Feb 2023 14:10:32 +0300 Subject: hurd: Refactor readlinkat() Make the code flow more linear using early returns where possible. This makes it so much easier to reason about what runs on error / successful code paths. Signed-off-by: Sergey Bugaev Message-Id: <20230212111044.610942-2-bugaevc@gmail.com> --- sysdeps/mach/hurd/readlinkat.c | 55 ++++++++++++++++++++++++------------------ 1 file changed, 32 insertions(+), 23 deletions(-) (limited to 'sysdeps') diff --git a/sysdeps/mach/hurd/readlinkat.c b/sysdeps/mach/hurd/readlinkat.c index 1efb09cae2..dabdbb3713 100644 --- a/sysdeps/mach/hurd/readlinkat.c +++ b/sysdeps/mach/hurd/readlinkat.c @@ -31,38 +31,47 @@ __readlinkat (int fd, const char *file_name, char *buf, size_t len) error_t err; file_t file_stat; struct stat64 st; + enum retry_type doretry; + char retryname[1024]; + file_t file; + char *rbuf = buf; file_stat = __file_name_lookup_at (fd, 0, file_name, O_NOLINK, 0); if (file_stat == MACH_PORT_NULL) return -1; err = __io_stat (file_stat, &st); - if (! err) - if (S_ISLNK (st.st_mode)) - { - enum retry_type doretry; - char retryname[1024]; - file_t file; - char *rbuf = buf; + if (err) + goto out; + if (!S_ISLNK (st.st_mode)) + { + err = EINVAL; + goto out; + } - err = __dir_lookup (file_stat, "", O_READ | O_NOLINK, 0, &doretry, retryname, &file); - if (! err && (doretry != FS_RETRY_NORMAL || retryname[0] != '\0')) - err = EGRATUITOUS; - if (! err) - { - err = __io_read (file, &rbuf, &len, 0, len); - if (!err && rbuf != buf) - { - memcpy (buf, rbuf, len); - __vm_deallocate (__mach_task_self (), (vm_address_t)rbuf, len); - } + err = __dir_lookup (file_stat, "", O_READ | O_NOLINK, + 0, &doretry, retryname, &file); + if (err) + goto out; + if (doretry != FS_RETRY_NORMAL || retryname[0] != '\0') + { + err = EGRATUITOUS; + goto out; + } + + err = __io_read (file, &rbuf, &len, 0, len); + __mach_port_deallocate (__mach_task_self (), file); + if (err) + goto out; + + if (rbuf != buf) + { + memcpy (buf, rbuf, len); + __vm_deallocate (__mach_task_self (), (vm_address_t) rbuf, len); + } - __mach_port_deallocate (__mach_task_self (), file); - } - } - else - err = EINVAL; + out: __mach_port_deallocate (__mach_task_self (), file_stat); return err ? __hurd_fail (err) : len; -- cgit 1.4.1