linux/drivers/block
Sergey SENOZHATSKY 1237275580 zram: keep the exact overcommited value in mem_used_max
`mem_used_max' is designed to store the max amount of memory zram consumed
to store the data.  However, it does not represent the actual
'overcommited' (max) value.  The existing code goes to -ENOMEM
overcommited case before it updates `->stats.max_used_pages', which hides
the reason we went to -ENOMEM in the first place -- we actually used more
memory than `->limit_pages':

        alloced_pages = zs_get_total_pages(meta->mem_pool);
        if (zram->limit_pages && alloced_pages > zram->limit_pages) {
                zs_free(meta->mem_pool, handle);
                ret = -ENOMEM;
                goto out;
        }

        update_used_max(zram, alloced_pages);

Which is misleading.  User will see -ENOMEM, check `->limit_pages', check
`->stats.max_used_pages', which will keep the value BEFORE zram passed
`->limit_pages', and see:
	`->stats.max_used_pages' < `->limit_pages'

Move update_used_max() before we do `->limit_pages' check, so that
user will see:
	`->stats.max_used_pages' > `->limit_pages'
should the overcommit and -ENOMEM happen.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
..
aoe Revert "block: remove artifical max_hw_sectors cap" 2015-08-18 13:21:13 -07:00
drbd mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM 2015-11-06 17:50:42 -08:00
mtip32xx mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM 2015-11-06 17:50:42 -08:00
paride mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM 2015-11-06 17:50:42 -08:00
rsxx block: make generic_make_request handle arbitrarily sized bios 2015-08-13 12:31:33 -06:00
xen-blkback xen/xenbus: Rename *RING_PAGE* to *RING_GRANT* 2015-10-23 14:20:46 +01:00
zram zram: keep the exact overcommited value in mem_used_max 2015-11-06 17:50:42 -08:00
amiflop.c block: drop owner assignment from platform_drivers 2014-10-20 16:20:18 +02:00
ataflop.c Merge branch 'for-3.16/core' of git://git.kernel.dk/linux-block into next 2014-06-02 09:29:34 -07:00
brd.c libnvdimm for 4.3: 2015-09-08 14:35:59 -07:00
cciss_cmd.h
cciss_scsi.c scsi: Do not set cmd_per_lun to 1 in the host template 2015-05-31 18:06:28 -07:00
cciss_scsi.h
cciss.c cciss: correct the non-resettable board list 2015-05-31 11:14:34 -07:00
cciss.h
cpqarray.c genirq: Remove the deprecated 'IRQF_DISABLED' request_irq() flag entirely 2015-03-05 20:53:06 +01:00
cpqarray.h
cryptoloop.c move linux/loop.h to drivers/block 2013-06-29 12:46:45 +04:00
DAC960.c block: use pci_zalloc_consistent 2014-08-08 15:57:28 -07:00
DAC960.h
floppy.c block: add a bi_error field to struct bio 2015-07-29 08:55:15 -06:00
hd.c block: hd: remove deprecated IRQF_DISABLED 2014-10-01 08:16:07 -06:00
ida_cmd.h
ida_ioctl.h
Kconfig nvme: move to a new drivers/nvme/host directory 2015-10-09 10:40:37 -06:00
loop.c Merge branch 'for-4.4/core' into for-4.4/drivers 2015-10-09 10:40:29 -06:00
loop.h block: loop: support DIO & AIO 2015-09-23 11:01:16 -06:00
Makefile nvme: move to a new drivers/nvme/host directory 2015-10-09 10:40:37 -06:00
mg_disk.c block: drop owner assignment from platform_drivers 2014-10-20 16:20:18 +02:00
nbd.c nbd: Add locking for tasks 2015-10-08 14:21:24 -06:00
null_blk.c blk-mq: fix racy updates of rq->errors 2015-10-01 10:10:55 +02:00
osdblk.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
pktcdvd.c mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM 2015-11-06 17:50:42 -08:00
ps3disk.c block: Kill bio_segments()/bi_vcnt usage 2013-11-23 22:33:51 -08:00
ps3vram.c block: make generic_make_request handle arbitrarily sized bios 2015-08-13 12:31:33 -06:00
rbd_types.h
rbd.c rbd: require stable pages if message data CRCs are enabled 2015-10-30 19:25:02 +01:00
skd_main.c block: have drivers use blk_queue_max_discard_sectors() 2015-07-17 08:41:53 -06:00
skd_s1120.h skd: fix formatting in skd_s1120.h 2013-11-08 09:10:30 -07:00
smart1,2.h
sunvdc.c sunvdc: reconnect ldc after vds service domain restarts 2014-12-11 18:52:45 -08:00
swim3.c powerpc: Move Power Macintosh drivers to generic byteswappers 2015-03-23 14:29:40 +11:00
swim_asm.S
swim.c block: drop owner assignment from platform_drivers 2014-10-20 16:20:18 +02:00
sx8.c block: rename REQ_TYPE_SPECIAL to REQ_TYPE_DRV_PRIV 2015-05-05 13:40:03 -06:00
umem.c block: make generic_make_request handle arbitrarily sized bios 2015-08-13 12:31:33 -06:00
umem.h
virtio_blk.c blk-mq: fix racy updates of rq->errors 2015-10-01 10:10:55 +02:00
xen-blkfront.c xen: features for 4.4-rc0 2015-11-04 17:32:42 -08:00
xsysace.c block: systemace: Remove .owner field for driver 2014-08-21 20:37:54 -05:00
z2ram.c block: remove struct request buffer member 2014-04-15 14:03:02 -06:00