diff options
Diffstat (limited to 'fs/overlayfs/inode.c')
| -rw-r--r-- | fs/overlayfs/inode.c | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 5bc71642b226..321511ed8c42 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -498,6 +498,9 @@ static int ovl_set_nlink_common(struct dentry *dentry, len = snprintf(buf, sizeof(buf), format, (int) (inode->i_nlink - realinode->i_nlink)); + if (WARN_ON(len >= sizeof(buf))) + return -EIO; + return ovl_do_setxattr(ovl_dentry_upper(dentry), OVL_XATTR_NLINK, buf, len, 0); } @@ -576,10 +579,13 @@ static int ovl_inode_set(struct inode *inode, void *data) static bool ovl_verify_inode(struct inode *inode, struct dentry *lowerdentry, struct dentry *upperdentry) { - struct inode *lowerinode = lowerdentry ? d_inode(lowerdentry) : NULL; - - /* Lower (origin) inode must match, even if NULL */ - if (ovl_inode_lower(inode) != lowerinode) + /* + * Allow non-NULL lower inode in ovl_inode even if lowerdentry is NULL. + * This happens when finding a copied up overlay inode for a renamed + * or hardlinked overlay dentry and lower dentry cannot be followed + * by origin because lower fs does not support file handles. + */ + if (lowerdentry && ovl_inode_lower(inode) != d_inode(lowerdentry)) return false; /* @@ -592,18 +598,30 @@ static bool ovl_verify_inode(struct inode *inode, struct dentry *lowerdentry, return true; } -struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry) +struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry, + struct dentry *index) { struct dentry *lowerdentry = ovl_dentry_lower(dentry); struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL; struct inode *inode; + /* Already indexed or could be indexed on copy up? */ + bool indexed = (index || (ovl_indexdir(dentry->d_sb) && !upperdentry)); + + if (WARN_ON(upperdentry && indexed && !lowerdentry)) + return ERR_PTR(-EIO); if (!realinode) realinode = d_inode(lowerdentry); - if (!S_ISDIR(realinode->i_mode) && - (upperdentry || (lowerdentry && ovl_indexdir(dentry->d_sb)))) { - struct inode *key = d_inode(lowerdentry ?: upperdentry); + /* + * Copy up origin (lower) may exist for non-indexed upper, but we must + * not use lower as hash key in that case. + * Hash inodes that are or could be indexed by origin inode and + * non-indexed upper inodes that could be hard linked by upper inode. + */ + if (!S_ISDIR(realinode->i_mode) && (upperdentry || indexed)) { + struct inode *key = d_inode(indexed ? lowerdentry : + upperdentry); unsigned int nlink; inode = iget5_locked(dentry->d_sb, (unsigned long) key, |