[PATCH] fs: System memory leak when running HTX with T10 DIF enabled

[wenxiong]

From: Wen Xiong <wenxiong@xxxxxxxxxxxxxxxxxx>

With nvme devive + T10 enabled, On a system it has 256GB and started
logging /proc/meminfo & /proc/slabinfo for every minute and in an hour
it increased by 15968128 kB or ~15+GB.. Approximately 256 MB / minute
leaking.

/proc/meminfo | grep SUnreclaim...

SUnreclaim:      6752128 kB
SUnreclaim:      6874880 kB
SUnreclaim:      7238080 kB
....
SUnreclaim:     22307264 kB
SUnreclaim:     22485888 kB
SUnreclaim:     22720256 kB

When testcases with T10 enabled call into __blkdev_direct_IO_simple,
code doesn't free memory allocated by bio_integrity_alloc. The patch
fixes the issue. HTX has been run with +60 hours without failure.

failing stack:

[36587.216329] [c000002ff60874a0] [c000000000bcac68]
dump_stack+0xb0/0xf0 (unreliable)
[36587.216349] [c000002ff60874e0] [c000000000bc8c94] panic+0x140/0x308
[36587.216407] [c000002ff6087570] [c000000000282530]
out_of_memory+0x4e0/0x650
[36587.216465] [c000002ff6087610] [c00000000028a154]
__alloc_pages_nodemask+0xf34/0x10b0
[36587.216534] [c000002ff6087810] [c00000000030b800]
alloc_pages_current+0xc0/0x1d0
[36587.216603] [c000002ff6087870] [c00000000031907c]
new_slab+0x46c/0x7d0
[36587.216661] [c000002ff6087950] [c00000000031bf00]
___slab_alloc+0x570/0x670
[36587.216718] [c000002ff6087a70] [c00000000031c05c]
__slab_alloc+0x5c/0x90
[36587.216776] [c000002ff6087ad0] [c00000000031c1f4]
kmem_cache_alloc+0x164/0x300
[36587.216845] [c000002ff6087b20] [c0000000002de120]
mmap_region+0x3e0/0x6e0
[36587.216903] [c000002ff6087c00] [c0000000002de7cc] do_mmap+0x3ac/0x480
[36587.216960] [c000002ff6087c80] [c0000000002af244]
vm_mmap_pgoff+0x114/0x160
[36587.217018] [c000002ff6087d60] [c0000000002db6b0]
SyS_mmap_pgoff+0x230/0x300
[36587.217087] [c000002ff6087de0] [c000000000014eac] sys_mmap+0x8c/0xd0
[36587.217145] [c000002ff6087e30] [c00000000000b184]
system_call+0x38/0xe0
[36587.217481] ---[ end Kernel panic - not syncing: Out of memory and no
killable processes...
[36587.217481]

Signed-off-by: Wen Xiong <wenxiong@xxxxxxxxxxxxxxxxxx>
Reviewed by:  Brian King <brking@xxxxxxxxxxxxxxxxxx>
Tested by: Murali Iyer <mniyer@xxxxxxxxxx>
---
 fs/block_dev.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 519599d..e871444 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -264,6 +264,10 @@ static void blkdev_bio_end_io_simple(struct bio *bio)
 
 	if (unlikely(bio.bi_error))
 		return bio.bi_error;
+
+	if (bio_integrity(&bio))
+		bio_integrity_free(&bio);
+
 	return ret;
 }
 
-- 
1.7.1