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| author | Mateusz Guzik <mjguzik@gmail.com> | 2025-10-01 03:00:10 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-10-20 20:22:25 +0200 |
| commit | be97a4b63ca8c3ed8f5c3f5606a15a8379c78afb (patch) | |
| tree | 100d145c595885eac56d969ad9555faa2473e81f /fs/inode.c | |
| parent | dc816f8d925cac34922ea73abd94ae23a96cacac (diff) | |
| download | random-be97a4b63ca8c3ed8f5c3f5606a15a8379c78afb.tar.gz | |
fs: assert on ->i_count in iput_final()
Notably make sure the count is 0 after the return from ->drop_inode(),
provided we are going to drop.
Inspired by suspicious games played by f2fs.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/inode.c')
| -rw-r--r-- | fs/inode.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/inode.c b/fs/inode.c index ec9339024ac36e..fa82cb810af440 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1879,6 +1879,7 @@ static void iput_final(struct inode *inode) int drop; WARN_ON(inode->i_state & I_NEW); + VFS_BUG_ON_INODE(atomic_read(&inode->i_count) != 0, inode); if (op->drop_inode) drop = op->drop_inode(inode); @@ -1893,6 +1894,12 @@ static void iput_final(struct inode *inode) return; } + /* + * Re-check ->i_count in case the ->drop_inode() hooks played games. + * Note we only execute this if the verdict was to drop the inode. + */ + VFS_BUG_ON_INODE(atomic_read(&inode->i_count) != 0, inode); + state = inode->i_state; if (!drop) { WRITE_ONCE(inode->i_state, state | I_WILL_FREE); |