On 8/3/11 2:02 PM, Christoph Hellwig wrote:
> On Wed, Aug 03, 2011 at 01:41:59PM -0500, Eric Sandeen wrote:
>> This is for RH bug 727938, xfs_fsr regression for root file system
>>
>> Fedora has made /etc/mtab a symlink to /proc/mounts, but when
>> we issue "xfs_fsr /" and fsr's getmntany() goes looking for
>> the "/" entry, the first one it finds is
>>
>> rootfs / rootfs rw 0 0
>>
>> it says no way, that's a rootfs filesystem type, not xfs!
>> And it never finds this later:
>>
>> /dev/sda2 / xfs rw,relatime,attr2,noquota 0 0
>>
>> This patch to skip over the rootfs entry seems to fix it.
>
> I don't like this. rootfs is the symptom, but the underlying problem
> is that in Linux we're perfectly fine to have multiple filesystems
> mounted on a single mountpoint, and the getmntany can't deal with it.
>
> I think the right fix is to simply remove the break from the loop,
It's not quite that simple.
when we do
*mp = *t;
/* break; */
we are pointing the mp string pointers at the strings in the getmntent entry,
which will keep moving as we iterate. We'll need a strdup or something
to copy it out on each good find, with appropriate frees etc, I guess.
Is there a better way to do it? This seems pretty ugly.
memset(mp, 0, sizeof(struct mntent));
while ((t = getmntent(fp))) {
if (mpref->mnt_fsname) { /* device */
if (stat64(t->mnt_fsname, &ms) < 0)
continue;
if (s->st_rdev != ms.st_rdev)
continue;
}
if (mpref->mnt_dir) { /* mount point */
if (stat64(t->mnt_dir, &ms) < 0)
continue;
if (s->st_ino != ms.st_ino || s->st_dev != ms.st_dev)
continue;
}
/* This one matches */
found = 1;
free(mp->mnt_fsname);
free(mp->mnt_dir);
free(mp->mnt_type);
mp->mnt_fsname = strdup(t->mnt_fsname);
mp->mnt_dir = strdup(t->mnt_dir);
mp->mnt_type = strdup(t->mnt_type);
}
return (found);
(and then free the strings in the caller when we're done ...)
-Eric
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