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authorJohannes Weiner <hannes@cmpxchg.org>2022-11-03 17:34:31 -0400
committerAndrew Morton <akpm@linux-foundation.org>2022-11-08 15:57:25 -0800
commit82e60d00b753bb5cfecce22b8e952436b14d02a3 (patch)
tree631fb24b9dcf69eb3010c2f05d2098f46f827abf /fs/erofs
parent8cccf05fe857a18ee26e20d11a8455a73ffd4efd (diff)
fs: fix leaked psi pressure state
When psi annotations were added to to btrfs compression reads, the psi state tracking over add_ra_bio_pages and btrfs_submit_compressed_read was faulty. A pressure state, once entered, is never left. This results in incorrectly elevated pressure, which triggers OOM kills. pflags record the *previous* memstall state when we enter a new one. The code tried to initialize pflags to 1, and then optimize the leave call when we either didn't enter a memstall, or were already inside a nested stall. However, there can be multiple PageWorkingset pages in the bio, at which point it's that path itself that enters repeatedly and overwrites pflags. This causes us to miss the exit. Enter the stall only once if needed, then unwind correctly. erofs has the same problem, fix that up too. And move the memstall exit past submit_bio() to restore submit accounting originally added by b8e24a9300b0 ("block: annotate refault stalls from IO submission"). Link: https://lkml.kernel.org/r/Y2UHRqthNUwuIQGS@cmpxchg.org Fixes: 4088a47e78f9 ("btrfs: add manual PSI accounting for compressed reads") Fixes: 99486c511f68 ("erofs: add manual PSI accounting for the compressed address space") Fixes: 118f3663fbc6 ("block: remove PSI accounting from the bio layer") Link: https://lore.kernel.org/r/d20a0a85-e415-cf78-27f9-77dd7a94bc8d@leemhuis.info/ Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Thorsten Leemhuis <linux@leemhuis.info> Tested-by: Thorsten Leemhuis <linux@leemhuis.info> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Sterba <dsterba@suse.com> Cc: Gao Xiang <xiang@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs/erofs')
-rw-r--r--fs/erofs/zdata.c18
1 files changed, 11 insertions, 7 deletions
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index c7f24fc7efd5..064a166324a7 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1412,8 +1412,8 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f,
struct block_device *last_bdev;
unsigned int nr_bios = 0;
struct bio *bio = NULL;
- /* initialize to 1 to make skip psi_memstall_leave unless needed */
- unsigned long pflags = 1;
+ unsigned long pflags;
+ int memstall = 0;
bi_private = jobqueueset_init(sb, q, fgq, force_fg);
qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head;
@@ -1463,14 +1463,18 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f,
if (bio && (cur != last_index + 1 ||
last_bdev != mdev.m_bdev)) {
submit_bio_retry:
- if (!pflags)
- psi_memstall_leave(&pflags);
submit_bio(bio);
+ if (memstall) {
+ psi_memstall_leave(&pflags);
+ memstall = 0;
+ }
bio = NULL;
}
- if (unlikely(PageWorkingset(page)))
+ if (unlikely(PageWorkingset(page)) && !memstall) {
psi_memstall_enter(&pflags);
+ memstall = 1;
+ }
if (!bio) {
bio = bio_alloc(mdev.m_bdev, BIO_MAX_VECS,
@@ -1500,9 +1504,9 @@ submit_bio_retry:
} while (owned_head != Z_EROFS_PCLUSTER_TAIL);
if (bio) {
- if (!pflags)
- psi_memstall_leave(&pflags);
submit_bio(bio);
+ if (memstall)
+ psi_memstall_leave(&pflags);
}
/*