On 2/17/21 11:24 PM, Gao Xiang wrote:

On Thu, Feb 18, 2021 at 10:41:59AM +0800, Gao Xiang wrote:

quoted

Hi Eric,

On Mon, Feb 15, 2021 at 07:04:25PM -0600, Eric Sandeen wrote:

quoted

On 10/12/20 11:06 PM, Gao Xiang wrote:

quoted

Check stripe numbers in calc_stripe_factors() by using
xfs_validate_stripe_geometry().

Signed-off-by: Gao Xiang <redacted>

Hm, unless I have made a mistake, this seems to allow an invalid
stripe specification.

Without this patch, this fails:

# mkfs/mkfs.xfs -f -d su=4097,sw=1 /dev/loop0
data su must be a multiple of the sector size (512)

With the patch:

# mkfs/mkfs.xfs -f -d su=4097,sw=1 /dev/loop0
meta-data=/dev/loop0             isize=512    agcount=8, agsize=32768 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=262144, imaxpct=25
         =                       sunit=1      swidth=1 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=1 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
Discarding blocks...Done.

When you are back from holiday, can you check? No big rush.

I'm back from holiday today. I think the problem is in
"if (dsu || dsw) {" it turns into "dsunit  = (int)BTOBBT(dsu);" anyway,
and then if (!libxfs_validate_stripe_geometry(NULL, BBTOB(dsunit),
					     BBTOB(dswidth), cfg->sectorsize, false))

so dsu isn't checked with sectorsize in advance before it turns into BB.

the fix seems simple though,
1) turn dsunit and dswidth into bytes rather than BB, but I have no idea the range of
   these 2 varibles, since I saw "if (big_dswidth > INT_MAX) {" but the big_dswidth
   was also in BB as well, if we turn these into bytes, and such range cannot be
   guarunteed...
2) recover the previous code snippet and check dsu in advance:
		if (dsu % cfg->sectorsize) {
			fprintf(stderr,
_("data su must be a multiple of the sector size (%d)\n"), cfg->sectorsize);
			usage();
		}

since we have this check already in xfs_validate_stripe_geometry, it seems best to
keep using it there, and not copy it ... which I think you accomplish below.

Just thinking through this... I think this is the right idea.

-		dsunit  = (int)BTOBBT(dsu);
-		big_dswidth = (long long int)dsunit * dsw;
+		big_dswidth = (long long int)dsu * dsw;

dsu is in bytes; this would mean big_dswidth is now also in bytes...
the original goal here, I think, is to not overflow the 32-bit superblock value
for dswidth.

 		if (big_dswidth > INT_MAX) {
 			fprintf(stderr,
 _("data stripe width (%lld) is too large of a multiple of the data stripe unit (%d)\n"),
 				big_dswidth, dsunit);

so this used to test big_dswidth in BB (sectors); but now it tests in bytes.

Perhaps this should change to check and report sectors again:

  		if (BTOBBT(big_dswidth) > INT_MAX) {
  			fprintf(stderr,
  _("data stripe width (%lld) is too large of a multiple of the data stripe unit (%d)\n"),
  				BTOBBT(big_dswidth), dsunit);

I think the goal is to not overflow the 32-bit on-disk values, which would be
easy to do with "dsw" specified as a /multiplier/ of "dsu"

So I think that if we keep range checking the value in BB units, it will be
OK.

 			usage();
 		}
-		dswidth = big_dswidth;
-	}
 
-	if (!libxfs_validate_stripe_geometry(NULL, BBTOB(dsunit), BBTOB(dswidth),
-					     cfg->sectorsize, false))
+		if (!libxfs_validate_stripe_geometry(NULL, dsu, big_dswidth,
+						     cfg->sectorsize, false))
+			usage();
+
+		dsunit = BTOBBT(dsu);
+		dswidth = BTOBBT(big_dswidth);
+	} else if (!libxfs_validate_stripe_geometry(NULL, BBTOB(dsunit),
+			BBTOB(dswidth), cfg->sectorsize, false)) {
 		usage();
+	}

Otherwise this looks reasonable to me; now it's basically:

1) If we got geometry in bytes, validate them directly
2) If we got geometry in BB, convert to bytes, and validate
3) If we got no geometry, validate the device-reported defaults

Thanks,
-Eric

 	/* If sunit & swidth were manually specified as 0, same as noalign */
 	if ((cli_opt_set(&dopts, D_SUNIT) || cli_opt_set(&dopts, D_SU)) &&