Re: [PATCH] Use xattr (Linux) in qcopy-acl.c

[Paul Eggert]

On 2023-01-04 06:46, Bruno Haible wrote:
> To me, it looks good. Paul's opinion?
I see a problem in linking. With this change, programs using the 
qcopy-acl module will link to both $(LIB_ACL) and $(LIB_XATTR), even 
though they do not need to link with $(LIB_ACL). Perhaps you can fix 
this by fixing the Link sections of the relevant modules to use 
$(LIB_HAS_ACL) instead of $(LIB_ACL). That is, for each module where you 
added $(LIB_XATTR), replace its $(LIB_ACL) with $(LIB_HAS_ACL) if the 
only reason it needed $(LIB_ACL) was to copy attributes.

Also, come to think of it, is there a security issue between the 
chmod_or_fchmod call, and the attr_copy_fd call? That is, could the file 
temporarily be set to too-generous permissions, between the two calls? A 
comment explaining this issue would help.