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| author | Kent Overstreet <kent.overstreet@linux.dev> | 2024-08-22 06:21:52 +0300 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-08-22 09:07:23 +0300 |
| commit | 0b50b7313ef2494926df30ce8e2ce284f1b847fc (patch) | |
| tree | e31051c61b62529648baeabfb05d543268dc5fba /fs | |
| parent | 8ed823b19214e403ca485532f48c0e02035021ae (diff) | |
| download | linux-0b50b7313ef2494926df30ce8e2ce284f1b847fc.tar.xz | |
bcachefs: Fix refcounting in discard path
bch_dev->io_ref does not protect against the filesystem going away;
bch_fs->writes does.
Thus the filesystem write ref needs to be the last ref we release.
Reported-by: syzbot+9e0404b505e604f67e41@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/bcachefs/alloc_background.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c index dc97b1f8bc08..ba46f1c1d78a 100644 --- a/fs/bcachefs/alloc_background.c +++ b/fs/bcachefs/alloc_background.c @@ -1874,26 +1874,26 @@ static void bch2_do_discards_work(struct work_struct *work) trace_discard_buckets(c, s.seen, s.open, s.need_journal_commit, s.discarded, bch2_err_str(ret)); - bch2_write_ref_put(c, BCH_WRITE_REF_discard); percpu_ref_put(&ca->io_ref); + bch2_write_ref_put(c, BCH_WRITE_REF_discard); } void bch2_dev_do_discards(struct bch_dev *ca) { struct bch_fs *c = ca->fs; - if (!bch2_dev_get_ioref(c, ca->dev_idx, WRITE)) + if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_discard)) return; - if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_discard)) - goto put_ioref; + if (!bch2_dev_get_ioref(c, ca->dev_idx, WRITE)) + goto put_write_ref; if (queue_work(c->write_ref_wq, &ca->discard_work)) return; - bch2_write_ref_put(c, BCH_WRITE_REF_discard); -put_ioref: percpu_ref_put(&ca->io_ref); +put_write_ref: + bch2_write_ref_put(c, BCH_WRITE_REF_discard); } void bch2_do_discards(struct bch_fs *c) |