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; > }
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