ovl: protect copying of realinode attributes to ovl inode

ovl_copyattr() may be called concurrently from aio completion context
without any lock and that could lead to overlay inode attributes getting
permanently out of sync with real inode attributes.

Use ovl inode spinlock to protect ovl_copyattr().

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
This commit is contained in:
Amir Goldstein 2023-08-24 14:51:17 +03:00
parent 389a4a4a19
commit f7621b11e8

View File

@ -1403,6 +1403,7 @@ void ovl_copyattr(struct inode *inode)
realinode = ovl_i_path_real(inode, &realpath);
real_idmap = mnt_idmap(realpath.mnt);
spin_lock(&inode->i_lock);
vfsuid = i_uid_into_vfsuid(real_idmap, realinode);
vfsgid = i_gid_into_vfsgid(real_idmap, realinode);
@ -1413,4 +1414,5 @@ void ovl_copyattr(struct inode *inode)
inode_set_mtime_to_ts(inode, inode_get_mtime(realinode));
inode_set_ctime_to_ts(inode, inode_get_ctime(realinode));
i_size_write(inode, i_size_read(realinode));
spin_unlock(&inode->i_lock);
}