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| author | Mateusz Guzik <mjguzik@gmail.com> | 2023-08-11 21:48:14 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2023-08-15 08:32:45 +0200 |
| commit | 45e0d4b95b65fedd18aa3e1b6571e16a2e6e0aa9 (patch) | |
| tree | 2b6aad56f217e7416cc8d37f7545b219340ea055 | |
| parent | 89cbd4c036ba44eadc495820e72c5c36273abb76 (diff) | |
| download | lwn-45e0d4b95b65fedd18aa3e1b6571e16a2e6e0aa9.tar.gz lwn-45e0d4b95b65fedd18aa3e1b6571e16a2e6e0aa9.zip | |
vfs: fix up the assert in i_readcount_dec
Drops a race where 2 threads could spot a positive value and both
proceed to dec to -1, without reporting anything.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Message-Id: <20230811194814.1612336-1-mjguzik@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | include/linux/fs.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 11055d00fab8..57e2a0a9eea1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2607,8 +2607,7 @@ static inline bool inode_is_open_for_write(const struct inode *inode) #if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING) static inline void i_readcount_dec(struct inode *inode) { - BUG_ON(!atomic_read(&inode->i_readcount)); - atomic_dec(&inode->i_readcount); + BUG_ON(atomic_dec_return(&inode->i_readcount) < 0); } static inline void i_readcount_inc(struct inode *inode) { |