Ingo Molnar wrote: > * Srinivasa Ds <srinivasa@xxxxxxxxxx> wrote: > >> On debugging I found out that,"dmsetup suspend <device name>" calls >> "freeze_bdev()",which locks "bd_mount_mutex" to make sure that no new >> mounts happen on bdev until thaw_bdev() is called. >> This "thaw_bdev()" is getting called when we resume the device >> through "dmsetup resume <device-name>". >> Hence we have 2 processes,one of which locks >> "bd_mount_mutex"(dmsetup suspend) and Another(dmsetup resume) unlocks >> it. > > hm, to me this seems quite a fragile construct - even if the > mutex-debugging warning is worked around by reverting to a semaphore. > > Ingo Ingo, what do you feel is fragile about this? It seems like this is a reasonable way to go, except that maybe a down_trylock would be good if a 2nd process tries to freeze while it's already frozen... Thanks, -Eric -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
