On 10/11/2017 04:16 AM, NeilBrown wrote:
On Tue, Oct 10 2017, Zhilong Liu wrote:
On 09/25/2017 01:52 PM, NeilBrown wrote:
Creating an array by opening a block-device with major number of 9
will transparently load the md module if needed.
Creating an array by opening
/sys/module/md_mod/parameters/new_array
and writing to it won't, it will just fail if md_mod isn't loaded.
So when opening that file fails with ENOENT, run "modprobe md_mod" and
try again.
This fixes a bug whereby if you have "CREATE names=yes" in mdadm.conf,
and the md modules isn't loaded, then creating or assembling an
array will not honor the "names=yes" configuration.
Signed-off-by: NeilBrown <neilb@xxxxxxxx>
---
mdopen.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/mdopen.c b/mdopen.c
index 3c0052f2db23..dcdc6f23e6c1 100644
--- a/mdopen.c
+++ b/mdopen.c
@@ -312,6 +312,10 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
if (block_udev)
udev_block(devnm);
fd = open("/sys/module/md_mod/parameters/new_array", O_WRONLY);
+ if (fd < 0 && errno == ENOENT) {
+ system("modprobe md_mod");
[nip]
Hmmm.. that's annoying. I wonder why "system" is marked
"warn_unused_result".
in /usr/include/stdlib.h:
...
712 /* Execute the given line as a shell command.
713
714 This function is a cancellation point and therefore not marked with
715 __THROW. */
716 extern int system (const char *__command) __wur;
...
the "warn_unused_result" is from the __wur parameter, re-compile mdadm
after delete the '__wur',
it works.
In this case I really don't care - I'm not convinced an extra error
message will really help.
Maybe
if (system("modprobe md_mod") == 0)
fd = open("/sys/......", O_WRONLY);
Agree.
We do what a better error message, then it should be based on 'fd < 0'.
e.g.
if (fd < 0 || n != strlen(devnm))
pr_err("Fail create array using /sys/module/md_mod/parameters/new_array\n");
you mean something like this?
diff --git a/mdopen.c b/mdopen.c
index dcdc6f2..9de347e 100644
--- a/mdopen.c
+++ b/mdopen.c
@@ -313,14 +313,17 @@ int create_mddev(char *dev, char *name, int autof,
int trustworthy,
udev_block(devnm);
fd = open("/sys/module/md_mod/parameters/new_array",
O_WRONLY);
if (fd < 0 && errno == ENOENT) {
- system("modprobe md_mod");
- fd =
open("/sys/module/md_mod/parameters/new_array", O_WRONLY);
+ if (system("modprobe md_mod") == 0)
+ fd =
open("/sys/module/md_mod/parameters/new_array",
+ O_WRONLY);
}
if (fd >= 0) {
n = write(fd, devnm, strlen(devnm));
close(fd);
}
- if (n < 0) {
+ if (fd < 0 || n != strlen(devnm)) {
+ pr_err("Fail create array using "
+ "/sys/module/md_mod/parameters/new_array\n");
devnm[0] = 0;
udev_unblock();
}
Thanks,
-Zhilong
Thanks,
NeilBrown
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
