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| author | Kent Overstreet <kent.overstreet@linux.dev> | 2024-05-04 12:55:44 -0400 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-05-06 10:58:17 -0400 |
| commit | 18b4abcead744322feb90ba31450e7d770e928bd (patch) | |
| tree | a0f18630106602e3e030d5a693119572e7856449 /fs/bcachefs | |
| parent | 3a2d0259274202432e5119463dd4cf5f9fabed98 (diff) | |
| download | lwn-18b4abcead744322feb90ba31450e7d770e928bd.tar.gz lwn-18b4abcead744322feb90ba31450e7d770e928bd.zip | |
bcachefs: Fix lifetime issue in device iterator helpers
bch2_get_next_dev() and bch2_get_next_online_dev() iterate over devices,
dropping and taking refs as they go; we can't access the previous device
(for ca->dev_idx) after we've dropped our ref to it, unless we take
rcu_read_lock() first.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs')
| -rw-r--r-- | fs/bcachefs/sb-members.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/bcachefs/sb-members.h b/fs/bcachefs/sb-members.h index 5efa64eca5f8..5bf27d30ca29 100644 --- a/fs/bcachefs/sb-members.h +++ b/fs/bcachefs/sb-members.h @@ -107,10 +107,10 @@ static inline struct bch_dev *__bch2_next_dev(struct bch_fs *c, struct bch_dev * static inline struct bch_dev *bch2_get_next_dev(struct bch_fs *c, struct bch_dev *ca) { + rcu_read_lock(); if (ca) percpu_ref_put(&ca->ref); - rcu_read_lock(); if ((ca = __bch2_next_dev(c, ca, NULL))) percpu_ref_get(&ca->ref); rcu_read_unlock(); @@ -132,10 +132,10 @@ static inline struct bch_dev *bch2_get_next_online_dev(struct bch_fs *c, struct bch_dev *ca, unsigned state_mask) { + rcu_read_lock(); if (ca) percpu_ref_put(&ca->io_ref); - rcu_read_lock(); while ((ca = __bch2_next_dev(c, ca, NULL)) && (!((1 << ca->mi.state) & state_mask) || !percpu_ref_tryget(&ca->io_ref))) |