From: James Simmons <jsimmons@infradead.org>
To: lustre-devel@lists.lustre.org
Subject: [lustre-devel] [PATCH 18/37] lustre: llite: Fix lock ordering in pagevec_dirty
Date: Wed, 15 Jul 2020 16:44:59 -0400 [thread overview]
Message-ID: <1594845918-29027-19-git-send-email-jsimmons@infradead.org> (raw)
In-Reply-To: <1594845918-29027-1-git-send-email-jsimmons@infradead.org>
From: Shaun Tancheff <shaun.tancheff@hpe.com>
In vvp_set_pagevec_dirty lock order between i_pages and
lock_page_memcg was inverted with the expectation that
no other users would conflict.
However in vvp_page_completion_write the call to
test_clear_page_writeback does expect to be able
to lock_page_memcg then lock i_pages which appears
to conflict with the original analysis.
The reported case shows as RCU stalls with
vvp_set_pagevec_dirty blocked attempting to lock i_pages.
Fixes: f8a5fb036ae ("lustre: vvp: dirty pages with pagevec")
HPE-bug-id: LUS-8798
WC-bug-id: https://jira.whamcloud.com/browse/LU-13746
Lustre-commit: c4ed9b0fb1013 ("LU-13476 llite: Fix lock ordering in pagevec_dirty")
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-on: https://review.whamcloud.com/38317
Reviewed-by: Wang Shilong <wshilong@ddn.com>
Reviewed-by: Patrick Farrell <farr0186@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
---
fs/lustre/llite/vvp_io.c | 34 +++++++++++++++++++++-------------
1 file changed, 21 insertions(+), 13 deletions(-)
diff --git a/fs/lustre/llite/vvp_io.c b/fs/lustre/llite/vvp_io.c
index 8edd3c1..7627431 100644
--- a/fs/lustre/llite/vvp_io.c
+++ b/fs/lustre/llite/vvp_io.c
@@ -897,19 +897,31 @@ void vvp_set_pagevec_dirty(struct pagevec *pvec)
struct page *page = pvec->pages[0];
struct address_space *mapping = page->mapping;
unsigned long flags;
+ unsigned long skip_pages = 0;
int count = pagevec_count(pvec);
int dirtied = 0;
- int i = 0;
-
- /* From set_page_dirty */
- for (i = 0; i < count; i++)
- ClearPageReclaim(pvec->pages[i]);
+ int i;
+ BUILD_BUG_ON(PAGEVEC_SIZE > BITS_PER_LONG);
LASSERTF(page->mapping,
"mapping must be set. page %p, page->private (cl_page) %p\n",
page, (void *) page->private);
- /* Rest of code derived from __set_page_dirty_nobuffers */
+ for (i = 0; i < count; i++) {
+ page = pvec->pages[i];
+
+ ClearPageReclaim(page);
+
+ lock_page_memcg(page);
+ if (TestSetPageDirty(page)) {
+ /* page is already dirty .. no extra work needed
+ * set a flag for the i'th page to be skipped
+ */
+ unlock_page_memcg(page);
+ skip_pages |= (1 << i);
+ }
+ }
+
xa_lock_irqsave(&mapping->i_pages, flags);
/* Notes on differences with __set_page_dirty_nobuffers:
@@ -920,17 +932,13 @@ void vvp_set_pagevec_dirty(struct pagevec *pvec)
* 3. No mapping is impossible. (Race w/truncate mentioned in
* dirty_nobuffers should be impossible because we hold the page lock.)
* 4. All mappings are the same because i/o is only to one file.
- * 5. We invert the lock order on lock_page_memcg(page) and the mapping
- * xa_lock, but this is the only function that should use that pair of
- * locks and it can't race because Lustre locks pages throughout i/o.
*/
for (i = 0; i < count; i++) {
page = pvec->pages[i];
- lock_page_memcg(page);
- if (TestSetPageDirty(page)) {
- unlock_page_memcg(page);
+ /* if the i'th page was unlocked above, skip it here */
+ if ((skip_pages >> i) & 1)
continue;
- }
+
LASSERTF(page->mapping == mapping,
"all pages must have the same mapping. page %p, mapping %p, first mapping %p\n",
page, page->mapping, mapping);
--
1.8.3.1
next prev parent reply other threads:[~2020-07-15 20:44 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-15 20:44 [lustre-devel] [PATCH 00/37] lustre: latest patches landed to OpenSFS 07/14/2020 James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 01/37] lustre: osc: fix osc_extent_find() James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 02/37] lustre: ldlm: check slv and limit before updating James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 03/37] lustre: sec: better struct sepol_downcall_data James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 04/37] lustre: obdclass: remove init to 0 from lustre_init_lsi() James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 05/37] lustre: ptlrpc: handle conn_hash rhashtable resize James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 06/37] lustre: lu_object: convert lu_object cache to rhashtable James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 07/37] lustre: osc: disable ext merging for rdma only pages and non-rdma James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 08/37] lnet: socklnd: fix local interface binding James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 09/37] lnet: o2iblnd: allocate init_qp_attr on stack James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 10/37] lnet: Fix some out-of-date comments James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 11/37] lnet: socklnd: don't fall-back to tcp_sendpage James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 12/37] lustre: ptlrpc: re-enterable signal_completed_replay() James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 13/37] lustre: obdcalss: ensure LCT_QUIESCENT take sync James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 14/37] lustre: remove some "#ifdef CONFIG*" from .c files James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 15/37] lustre: obdclass: use offset instead of cp_linkage James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 16/37] lustre: obdclass: re-declare cl_page variables to reduce its size James Simmons
2020-07-15 20:44 ` [lustre-devel] [PATCH 17/37] lustre: osc: re-declare ops_from/to to shrink osc_page James Simmons
2020-07-15 20:44 ` James Simmons [this message]
2020-07-15 20:45 ` [lustre-devel] [PATCH 19/37] lustre: misc: quiet compiler warning on armv7l James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 20/37] lustre: llite: fix to free cl_dio_aio properly James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 21/37] lnet: o2iblnd: Use ib_mtu_int_to_enum() James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 22/37] lnet: o2iblnd: wait properly for fps->increasing James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 23/37] lnet: o2iblnd: use need_resched() James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 24/37] lnet: o2iblnd: Use list_for_each_entry_safe James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 25/37] lnet: socklnd: use need_resched() James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 26/37] lnet: socklnd: use list_for_each_entry_safe() James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 27/37] lnet: socklnd: convert various refcounts to refcount_t James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 28/37] lnet: libcfs: don't call unshare_fs_struct() James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 29/37] lnet: Allow router to forward to healthier NID James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 30/37] lustre: llite: annotate non-owner locking James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 31/37] lustre: osc: consume grants for direct I/O James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 32/37] lnet: remove LNetMEUnlink and clean up related code James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 33/37] lnet: Set remote NI status in lnet_notify James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 34/37] lustre: ptlrpc: fix endless loop issue James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 35/37] lustre: llite: fix short io for AIO James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 36/37] lnet: socklnd: change ksnd_nthreads to atomic_t James Simmons
2020-07-15 20:45 ` [lustre-devel] [PATCH 37/37] lnet: check rtr_nid is a gateway James Simmons
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