On Mon, Jun 30, 2014 at 07:59:03PM +0100, Burton, Ross wrote:
> On 30 June 2014 19:43, Darrick J. Wong <darrick.wong@xxxxxxxxxx> wrote:
> >> + retval = ext2fs_xattrs_open(fs, ino, &handle);
> >
> > If the FS does not have at least one of the inline_data or ext_attr features
> > turned on, the ext2fs_xattrs_open call returns EXT2_ET_MISSING_EA_FEATURE,
> > which aborts the whole operation. Is that ok?
>
> Good point.
>
> I'm currently dithering over whether this should silently do nothing,
> or warn per file, or have an already-warned boolean to avoid spamming
> the user.
>
> >> + if (retval) {
> >> + com_err(__func__, errno, "while opening inode %u", ino);
> >
> > retval, not errno.
>
> Literally just squashing some commits for these error paths which went wrong.
>
> >> + return errno;
> >> + }
> >> +
> >> + list = malloc(size);
> >
> > What happens if malloc fails?
>
> You're doomed?
>
> What's e2fsprog's policy on OOM - I see some instances of checked
> malloc() that exit() promptly, others that simply return 0 and hope
> for the best, and some that use fputs() and gettext() - but if we're
> OOM then that's even more likely to fail.
>
> I'll follow the official line, but what that line is isn't clear from
> a sample of malloc() calls in the source.
if (!list) com_err(__func__, ENOMEM, "while _______");
as a starting point. Better to print a nice error and exit than to simply
crash on the null pointer dereference.
I suppose you could also do the retval = ext2fs_get_mem(size, &list);
construction as well.
--D
>
> >> + size = llistxattr(filename, list, size);
> >
> > What if this second call should fail for some reason? Shouldn't we stop?
>
> Yes, also fixed locally.
>
> >> +
> >> + for (i = 0; i < size; i += strlen(&list[i]) + 1) {
> >> + const char *name = &list[i];
> >> + char *value;
> >> +
> >> + value_size = getxattr(filename, name, NULL, 0);
> >
> > What if getxattr returns -1?
>
> Should bail, will fix.
>
> >> + value = malloc(value_size);
> >> + value_size = getxattr(filename, name, value, value_size);
> >
> > Same complaints about not checking malloc/getxattr return values.
>
> Agreed.
>
> >> + retval = ext2fs_xattrs_close(&handle);
> >> + if (retval)
> >> + com_err(__func__, errno, "while closing inode %u", ino);
> >
> > retval, not errno.
>
> [sags head in shame]
>
> Next time I'm patching at 10pm I'll remember to review the patch the
> next morning before sending...
>
> Ross
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