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>
This commit is contained in:
Mateusz Guzik 2023-08-11 21:48:14 +02:00 committed by Christian Brauner
parent 89cbd4c036
commit 45e0d4b95b

View file

@ -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)
{