Donet Tom 3a103b5315 selftest: mm: Test if hugepage does not get leaked during __bio_release_pages() ... Commit 1b151e2435 ("block: Remove special-casing of compound pages") caused a change in behaviour when releasing the pages if the buffer does not start at the beginning of the page. This was because the calculation of the number of pages to release was incorrect. This was fixed by commit 38b43539d6 ("block: Fix page refcounts for unaligned buffers in __bio_release_pages()"). We pin the user buffer during direct I/O writes. If this buffer is a hugepage, bio_release_page() will unpin it and decrement all references and pin counts at ->bi_end_io. However, if any references to the hugepage remain post-I/O, the hugepage will not be freed upon unmap, leading to a memory leak. This patch verifies that a hugepage, used as a user buffer for DIO operations, is correctly freed upon unmapping, regardless of whether the offsets are aligned or unaligned w.r.t page boundary. Test Result Fail Scenario (Without the fix) -------------------------------------------------------- []# ./hugetlb_dio TAP version 13 1..4 No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 1 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 2 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 3 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 6 not ok 4 : Huge pages not freed! Totals: pass:3 fail:1 xfail:0 xpass:0 skip:0 error:0 Test Result PASS Scenario (With the fix) --------------------------------------------------------- []#./hugetlb_dio TAP version 13 1..4 No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 1 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 2 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 3 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 4 : Huge pages freed successfully ! Totals: pass:4 fail:0 xfail:0 xpass:0 skip:0 error:0 [donettom@linux.ibm.com: address review comments from Muhammad] Link: https://lkml.kernel.org/r/20240604132801.23377-1-donettom@linux.ibm.com [donettom@linux.ibm.com: add this test to run_vmtests.sh] Link: https://lkml.kernel.org/r/20240607182000.6494-1-donettom@linux.ibm.com Link: https://lkml.kernel.org/r/20240523063905.3173-1-donettom@linux.ibm.com Fixes: 38b43539d6 ("block: Fix page refcounts for unaligned buffers in __bio_release_pages()") Signed-off-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Co-developed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tony Battersby <tonyb@cybernetics.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>		2024-07-03 19:29:59 -07:00
..
accounting
arch	tools headers arm64: Sync arm64's cputype.h with the kernel sources	2024-06-04 16:46:40 -03:00
bootconfig
bpf	bpf: Fix potential integer overflow in resolve_btfids	2024-05-24 17:12:12 +02:00
build
certs
cgroup	proc: rewrite stable_page_flags()	2024-04-25 20:56:15 -07:00
counter
crypto
debugging
firewire
firmware
gpio
hv	tools: hv: suppress the invalid warning for packed member alignment	2024-05-28 05:27:35 +00:00
iio
include	perf tools fixes for v6.10: 2nd batch	2024-06-09 09:04:51 -07:00
kvm/kvm_stat
laptop
leds
lib	libbpf: don't close(-1) in multi-uprobe feature detector	2024-05-31 14:56:51 -07:00
memory-model
mm
net/ynl	ynl: ensure exact-len value is resolved	2024-05-13 14:59:24 -07:00
objtool
pci
pcmcia
perf	perf bpf: Fix handling of minimal vmlinux.h file when interrupting the build	2024-06-05 11:33:00 -03:00
power	tools/power turbostat: Add local build_bug.h header for snapshot target	2024-06-27 23:53:27 -04:00
rcu
scripts
sound	ASoC: dapm-graph: new tool to visualize DAPM state	2024-04-21 09:58:17 +09:00
spi
testing	selftest: mm: Test if hugepage does not get leaked during __bio_release_pages()	2024-07-03 19:29:59 -07:00
thermal
time
tracing	tools/latency-collector: Fix -Wformat-security compile warns	2024-05-23 10:46:01 -04:00
usb
verification
virtio
wmi
workqueue
writeback	writeback: add wb_monitor.py script to monitor writeback info on bdi	2024-05-05 17:53:51 -07:00
Makefile