Messages in this thread Patch in this message | | | Date | Wed, 6 May 2015 17:10:29 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCHv4 00/10] add on-demand device creation |
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On (05/06/15 16:28), Minchan Kim wrote: > > > > from your logs: > > ... > > [ 98.756017] zram: Removed device: zram2 > > [ 98.757087] ------------[ cut here ]------------ > > ... > > > > locked zram_index_mutex, removed zram2, unlocked zram_index_mutex, > > locked zram_index_mutex, attempted to create zram2: zram2 sysfs already exist. > > > > > > hm... need to think. zram hot/remove is serialized. > > I never look at the code but I doubt others(ex, some admin process on my machine) > holds a ref so kobj doesn't disapper yet but zram_add try to create it? >
well, something like this is certainly happening. hm, if this is the case, then a very quick thing I can think of is to stop re-using previously used zram ids. add_disk() doesn't give us a chance to handle any errors and testing for sysfs leftovers in zram_add() looks weird.
btw, do you also want me to rename zram-control sysfs handlers? zram_add -> zram_hot_add() ? i think zram_add()/zram_remove() is just ok.
can you please test this patch?
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drivers/block/zram/zram_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index e6c4316..b31f0c20 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1184,7 +1184,7 @@ static int zram_add(void) if (!zram) return -ENOMEM; - ret = idr_alloc(&zram_index_idr, zram, 0, 0, GFP_KERNEL); + ret = idr_alloc_cyclic(&zram_index_idr, zram, 0, 0, GFP_KERNEL); if (ret < 0) goto out_free_dev; device_id = ret;
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