On Thu, Feb 02, 2023 at 12:27:06PM +0100, Mateusz Grzonka wrote:
> Add kernel style comments and better error handling.
>
> Signed-off-by: Mateusz Grzonka <mateusz.grzonka@xxxxxxxxx>
Acked-by: Coly Li <colyli@xxxxxxx>
> ---
> Create.c | 1 +
> lib.c | 29 -----------------------------
> mdadm.h | 2 --
> mdopen.c | 12 ++++++------
> udev.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> udev.h | 2 ++
> 6 files changed, 53 insertions(+), 37 deletions(-)
>
> diff --git a/Create.c b/Create.c
> index 953e7372..666a8c92 100644
> --- a/Create.c
> +++ b/Create.c
> @@ -23,6 +23,7 @@
> */
>
> #include "mdadm.h"
> +#include "udev.h"
> #include "md_u.h"
> #include "md_p.h"
> #include <ctype.h>
> diff --git a/lib.c b/lib.c
> index 96ba6e8d..24cd10e3 100644
> --- a/lib.c
> +++ b/lib.c
> @@ -186,35 +186,6 @@ char *fd2devnm(int fd)
> return NULL;
> }
>
> -/* When we create a new array, we don't want the content to
> - * be immediately examined by udev - it is probably meaningless.
> - * So create /run/mdadm/creating-mdXXX and expect that a udev
> - * rule will noticed this and act accordingly.
> - */
> -static char block_path[] = "/run/mdadm/creating-%s";
> -static char *unblock_path = NULL;
> -void udev_block(char *devnm)
> -{
> - int fd;
> - char *path = NULL;
> -
> - xasprintf(&path, block_path, devnm);
> - fd = open(path, O_CREAT|O_RDWR, 0600);
> - if (fd >= 0) {
> - close(fd);
> - unblock_path = path;
> - } else
> - free(path);
> -}
> -
> -void udev_unblock(void)
> -{
> - if (unblock_path)
> - unlink(unblock_path);
> - free(unblock_path);
> - unblock_path = NULL;
> -}
> -
> /*
> * convert a major/minor pair for a block device into a name in /dev, if possible.
> * On the first call, walk /dev collecting name.
> diff --git a/mdadm.h b/mdadm.h
> index 23c10a52..5607c599 100644
> --- a/mdadm.h
> +++ b/mdadm.h
> @@ -1729,8 +1729,6 @@ extern char *fd2kname(int fd);
> extern char *stat2devnm(struct stat *st);
> bool stat_is_md_dev(struct stat *st);
> extern char *fd2devnm(int fd);
> -extern void udev_block(char *devnm);
> -extern void udev_unblock(void);
>
> extern int in_initrd(void);
>
> diff --git a/mdopen.c b/mdopen.c
> index afec34a4..ef34613a 100644
> --- a/mdopen.c
> +++ b/mdopen.c
> @@ -336,8 +336,8 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
> devnm[0] = 0;
> if (num < 0 && cname && ci->names) {
> sprintf(devnm, "md_%s", cname);
> - if (block_udev)
> - udev_block(devnm);
> + if (block_udev && udev_block(devnm) != UDEV_STATUS_SUCCESS)
> + return -1;
> if (!create_named_array(devnm)) {
> devnm[0] = 0;
> udev_unblock();
> @@ -345,8 +345,8 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
> }
> if (num >= 0) {
> sprintf(devnm, "md%d", num);
> - if (block_udev)
> - udev_block(devnm);
> + if (block_udev && udev_block(devnm) != UDEV_STATUS_SUCCESS)
> + return -1;
> if (!create_named_array(devnm)) {
> devnm[0] = 0;
> udev_unblock();
> @@ -369,8 +369,8 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
> return -1;
> }
> }
> - if (block_udev)
> - udev_block(devnm);
> + if (block_udev && udev_block(devnm) != UDEV_STATUS_SUCCESS)
> + return -1;
> }
>
> sprintf(devname, "/dev/%s", devnm);
> diff --git a/udev.c b/udev.c
> index 72a38f47..5389e5df 100644
> --- a/udev.c
> +++ b/udev.c
> @@ -30,6 +30,7 @@
>
> static struct udev *udev;
> static struct udev_monitor *udev_monitor;
> +static char *unblock_path;
>
> /*
> * udev_is_available() - Checks for udev in the system.
> @@ -145,3 +146,46 @@ void udev_release(void)
> udev_monitor_unref(udev_monitor);
> udev_unref(udev);
> }
> +
> +/*
> + * udev_block() - Block udev from examining newly created arrays.
> + *
> + * When array is created, we don't want udev to examine it immediately.
> + * Function creates /run/mdadm/creating-mdXXX and expects that udev rule
> + * will notice it and act accordingly.
> + *
> + * Return:
> + * UDEV_STATUS_SUCCESS when successfully blocked udev
> + * UDEV_STATUS_ERROR on error
> + */
> +enum udev_status udev_block(char *devnm)
> +{
> + int fd;
> + char *path = xcalloc(1, BUFSIZ);
> +
> + snprintf(path, BUFSIZ, "/run/mdadm/creating-%s", devnm);
> +
> + fd = open(path, O_CREAT | O_RDWR, 0600);
> + if (!is_fd_valid(fd)) {
> + pr_err("Cannot block udev, error creating blocking file.\n");
> + pr_err("%s: %s\n", strerror(errno), path);
> + free(path);
> + return UDEV_STATUS_ERROR;
> + }
> +
> + close(fd);
> + unblock_path = path;
> + return UDEV_STATUS_SUCCESS;
> +}
> +
> +/*
> + * udev_unblock() - Unblock udev.
> + */
> +void udev_unblock(void)
> +{
> + if (unblock_path)
> + unlink(unblock_path);
> + free(unblock_path);
> + unblock_path = NULL;
> +}
> +
> diff --git a/udev.h b/udev.h
> index 515366e7..e4da29cc 100644
> --- a/udev.h
> +++ b/udev.h
> @@ -32,5 +32,7 @@ bool udev_is_available(void);
> enum udev_status udev_initialize(void);
> enum udev_status udev_wait_for_events(int seconds);
> void udev_release(void);
> +enum udev_status udev_block(char *devnm);
> +void udev_unblock(void);
>
> #endif
> --
> 2.26.2
>
--
Coly Li
