On Tue, 07 Feb 2012 15:03:59 +0100 Adam Kwolek <adam.kwolek@xxxxxxxxx> wrote:
> When reshape is broken, it can occur that metadata is not saved properly.
> This can cause that reshape process is farther in md than metadata states.
>
> On reshape restart use md position as start position, if it is farther than
> position specified in metadata. Opposite situation treat as error.
>
> Signed-off-by: Adam Kwolek <adam.kwolek@xxxxxxxxx>
> ---
>
> Grow.c | 86 +++++++++++++++++++++++++++++++++++++++++++++-------------------
> 1 files changed, 60 insertions(+), 26 deletions(-)
>
> diff --git a/Grow.c b/Grow.c
> index 70bdee1..0668a16 100644
> --- a/Grow.c
> +++ b/Grow.c
> @@ -1862,6 +1862,55 @@ release:
> return rv;
> }
>
> +/* verify_reshape_position()
> + * Function checks if reshape position in metadata is not farther
> + * than position in md.
> + * Return value:
> + * 0 : not valid sysfs entry
> + * it can be caused by not started reshape, it should be started
> + * by reshape array or raid0 array is before takeover
> + * -1 : error, reshape position is obviously wrong
> + * 1 : success, reshape progress correct or updated
> +*/
> +static int verify_reshape_position(struct mdinfo *info, int level)
> +{
> + int ret_val = 0;
> + char buf[40];
> +
> + /* read sync_max, failure can mean raid0 array */
> + if (sysfs_get_str(info, NULL, "sync_max", buf, 40) > 0) {
> + char *ep;
> + unsigned long long position = strtoull(buf, &ep, 0);
> +
> + dprintf(Name": Read sync_max sysfs entry is: %s\n", buf);
> + if (!(ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))) {
> + position *= get_data_disks(level,
> + info->new_layout,
> + info->array.raid_disks);
> + if (info->reshape_progress < position) {
> + dprintf("Corrected reshape progress (%llu) to "
> + "md position (%llu)\n",
> + info->reshape_progress, position);
> + info->reshape_progress = position;
> + ret_val = 1;
> + } else if (info->reshape_progress > position) {
> + fprintf(stderr, Name ": Fatal error: array "
> + "reshape was not properly frozen "
> + "(expected reshape position is %llu, "
> + "but reshape progress is %llu.\n",
> + position, info->reshape_progress);
> + ret_val = -1;
> + } else {
> + dprintf("Reshape position in md and metadata "
> + "are the same;");
> + ret_val = 1;
> + }
> + }
> + }
> +
> + return ret_val;
> +}
> +
> static int reshape_array(char *container, int fd, char *devname,
> struct supertype *st, struct mdinfo *info,
> int force, struct mddev_dev *devlist,
> @@ -2251,9 +2300,16 @@ started:
>
> sra->new_chunk = info->new_chunk;
>
> - if (restart)
> + if (restart) {
> + /* for external metadata checkpoint saved by mdmon can be lost
> + * or missed /due to e.g. crash/. Check if md is not during
> + * restart farther than metadata points to.
> + * If so, this means metadata information is obsolete.
> + */
> + if (st->ss->external)
> + verify_reshape_position(info, reshape.level);
> sra->reshape_progress = info->reshape_progress;
> - else {
> + } else {
> sra->reshape_progress = 0;
> if (reshape.after.data_disks < reshape.before.data_disks)
> /* start from the end of the new array */
> @@ -3765,8 +3821,6 @@ int Grow_continue_command(char *devname, int fd,
> char buf[40];
> int cfd = -1;
> int fd2 = -1;
> - char *ep;
> - unsigned long long position;
>
> dprintf("Grow continue from command line called for %s\n",
> devname);
> @@ -3894,28 +3948,8 @@ int Grow_continue_command(char *devname, int fd,
> /* verify that array under reshape is started from
> * correct position
> */
> - ret_val = sysfs_get_str(content, NULL, "sync_max", buf, 40);
> - if (ret_val <= 0) {
^^^
This test is '<=' however ...
> - fprintf(stderr, Name
> - ": cannot open verify reshape progress for %s (%i)\n",
> - content->sys_name, ret_val);
> - ret_val = 1;
> - goto Grow_continue_command_exit;
> - }
> - dprintf(Name ": Read sync_max sysfs entry is: %s\n", buf);
> - position = strtoull(buf, &ep, 0);
> - if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' ')) {
> - fprintf(stderr, Name ": Fatal error: array reshape was"
> - " not properly frozen\n");
> - ret_val = 1;
> - goto Grow_continue_command_exit;
> - }
> - position *= get_data_disks(map_name(pers, mdstat->level),
> - content->new_layout,
> - content->array.raid_disks);
> - if (position != content->reshape_progress) {
> - fprintf(stderr, Name ": Fatal error: array reshape was"
> - " not properly frozen.\n");
> + if (verify_reshape_position(content,
> + map_name(pers, mdstat->level)) < 0) {
^^
this one is just '<'. However it looks like it should be the same.
Was there a reason for the change, or was it an oversight?
Thanks,
NeilBrown
> ret_val = 1;
> goto Grow_continue_command_exit;
> }
Attachment:
signature.asc
Description: PGP signature
