[PATCH v2 5/5] fs: Add inode_assert_locked() and inode_assert_locked_excl()

Matthew Wilcox (Oracle)
2023-10-07T20:36:14Z

Use the new rwsem_assert_held functions to implement these new
assertions. Convert the inode_is_locked() callers in the VFS to
use them.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/attr.c | 2 +-
fs/namei.c | 6 +++---
include/linux/fs.h | 10 ++++++++++
3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/fs/attr.c b/fs/attr.c
index a8ae5f6d9b16..5e32b0a4f8c2 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -387,7 +387,7 @@ int notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
struct timespec64 now;
unsigned int ia_valid = attr->ia_valid;

- WARN_ON_ONCE(!inode_is_locked(inode));
+ inode_assert_locked_excl(inode);

error = may_setattr(idmap, inode, ia_valid);
if (error)
diff --git a/fs/namei.c b/fs/namei.c
index 567ee547492b..6b595ad4318d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2708,7 +2708,7 @@ struct dentry *try_lookup_one_len(const char *name, struct dentry *base, int len
struct qstr this;
int err;

- WARN_ON_ONCE(!inode_is_locked(base->d_inode));
+ inode_assert_locked(base->d_inode);

err = lookup_one_common(&nop_mnt_idmap, name, base, len, &this);
if (err)
@@ -2735,7 +2735,7 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
struct qstr this;
int err;

- WARN_ON_ONCE(!inode_is_locked(base->d_inode));
+ inode_assert_locked(base->d_inode);

err = lookup_one_common(&nop_mnt_idmap, name, base, len, &this);
if (err)
@@ -2765,7 +2765,7 @@ struct dentry *lookup_one(struct mnt_idmap *idmap, const char *name,
struct qstr this;
int err;

- WARN_ON_ONCE(!inode_is_locked(base->d_inode));
+ inode_assert_locked(base->d_inode);

err = lookup_one_common(idmap, name, base, len, &this);
if (err)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b528f063e8ff..e01e041c102b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -832,6 +832,16 @@ static inline int inode_is_locked(struct inode *inode)
return rwsem_is_locked(&inode->i_rwsem);
}

+static inline void inode_assert_locked(const struct inode *inode)
+{
+ rwsem_assert_held(&inode->i_rwsem);
+}
+
+static inline void inode_assert_locked_excl(const struct inode *inode)
+{
+ rwsem_assert_held_write(&inode->i_rwsem);
+}
+
static inline void inode_lock_nested(struct inode *inode, unsigned subclass)
{
down_write_nested(&inode->i_rwsem, subclass);
--
2.40.1