On 04/17/2017 07:48 PM, NeilBrown wrote:
On Fri, Apr 14 2017, Jes Sorensen wrote:Looking some more at this, it may be simpler than I thought. How about this approach (only compile tested): int md_array_active(int fd) { struct mdinfo *sra; struct mdu_array_info_s array; int ret; sra = sysfs_read(fd, NULL, GET_VERSION | GET_DISKS); if (sra) { if (!sra->array.raid_disks && !(sra->array.major_version == -1 && sra->array.minor_version == -2)) ret = -ENODEV; else ret = 0; free(sra); } else { ret = ioctl(fd, GET_ARRAY_INFO, &array); } return !ret; } Note 'major = -1 && minor = -2' is sysfs_read's way of saying 'external'. This pretty much mimics what the kernel does in the ioctl handler for GET_ARRAY_INFO: case GET_ARRAY_INFO: if (!mddev->raid_disks && !mddev->external) err = -ENODEV; else err = get_array_info(mddev, argp); goto out; What do you think?I think that it accurately mimics what the current code does. I'm not sure that is what we really want. For testing in Incremental.c if an array is "active" we really should be testing more than "raid_disks != 0". We should be testing, as Shaohua suggested, if array_state != 'clear' or 'inactive'. You cannot get that info through the ioctl interface, so I suppose I decided the current test was 'close enough'. If we are going to stop supported kernels that don't have (e.g.) array_state, then we should really fo the right thing and test array_state.
I think I got it right this time and pushed it into git. It made things a lot prettier too IMHO :)
In the process I also changed the behavior of sysfs_read(GET_ARRAY_STATE) as I really didn't like how it was copying in the string rather than parsing it.
I am traveling at the moment and don't yet have my new raid test box setup back at the office, so my testing is limited. If I broke something badly, feel free to throw rotten tomatoes at me.
Cheers, Jes -- 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
