Merge patch series "include/linux/fs.h: add inode_lock_killable()"

Try and make a few filesystem operations killable on the VFS
inode->i_mutex level.

* patches from https://lore.kernel.org/[email protected]:
  fs/read_write: make default_llseek() killable
  fs/open: make do_truncate() killable
  fs/open: make chmod_common() and chown_common() killable
  include/linux/fs.h: add inode_lock_killable()

Link: https://lore.kernel.org/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

Author: brauner

fs/open.c

@@ -60,7 +60,10 @@ int do_truncate(struct mnt_idmap *idmap, struct dentry *dentry,
 	if (ret)
 		newattrs.ia_valid |= ret | ATTR_FORCE;
 
-	inode_lock(dentry->d_inode);
+	ret = inode_lock_killable(dentry->d_inode);
+	if (ret)
+		return ret;
+
 	/* Note any delegations or leases have already been broken: */
 	ret = notify_change(idmap, dentry, &newattrs, NULL);
 	inode_unlock(dentry->d_inode);
@@ -635,7 +638,9 @@ int chmod_common(const struct path *path, umode_t mode)
 	if (error)
 		return error;
 retry_deleg:
-	inode_lock(inode);
+	error = inode_lock_killable(inode);
+	if (error)
+		goto out_mnt_unlock;
 	error = security_path_chmod(path, mode);
 	if (error)
 		goto out_unlock;
@@ -650,6 +655,7 @@ int chmod_common(const struct path *path, umode_t mode)
 		if (!error)
 			goto retry_deleg;
 	}
+out_mnt_unlock:
 	mnt_drop_write(path->mnt);
 	return error;
 }
@@ -769,7 +775,9 @@ int chown_common(const struct path *path, uid_t user, gid_t group)
 		return -EINVAL;
 	if ((group != (gid_t)-1) && !setattr_vfsgid(&newattrs, gid))
 		return -EINVAL;
-	inode_lock(inode);
+	error = inode_lock_killable(inode);
+	if (error)
+		return error;
 	if (!S_ISDIR(inode->i_mode))
 		newattrs.ia_valid |= ATTR_KILL_SUID | ATTR_KILL_PRIV |
 				     setattr_should_drop_sgid(idmap, inode);

fs/read_write.c

@@ -332,7 +332,9 @@ loff_t default_llseek(struct file *file, loff_t offset, int whence)
 	struct inode *inode = file_inode(file);
 	loff_t retval;
 
-	inode_lock(inode);
+	retval = inode_lock_killable(inode);
+	if (retval)
+		return retval;
 	switch (whence) {
 		case SEEK_END:
 			offset += i_size_read(inode);

include/linux/fs.h

@@ -867,6 +867,11 @@ static inline void inode_lock(struct inode *inode)
 	down_write(&inode->i_rwsem);
 }
 
+static inline __must_check int inode_lock_killable(struct inode *inode)
+{
+	return down_write_killable(&inode->i_rwsem);
+}
+
 static inline void inode_unlock(struct inode *inode)
 {
 	up_write(&inode->i_rwsem);
@@ -877,6 +882,11 @@ static inline void inode_lock_shared(struct inode *inode)
 	down_read(&inode->i_rwsem);
 }
 
+static inline __must_check int inode_lock_shared_killable(struct inode *inode)
+{
+	return down_read_killable(&inode->i_rwsem);
+}
+
 static inline void inode_unlock_shared(struct inode *inode)
 {
 	up_read(&inode->i_rwsem);