Commit e6da7c9f authored by Eric Sandeen's avatar Eric Sandeen Committed by Felix Blyakher

xfs: fix overflow in xfs_growfs_data_private

In the case where growing a filesystem would leave the last AG
too small, the fixup code has an overflow in the calculation
of the new size with one fewer ag, because "nagcount" is a 32
bit number.  If the new filesystem has > 2^32 blocks in it
this causes a problem resulting in an EINVAL return from growfs:

 # xfs_io -f -c "truncate 19998630180864" fsfile
 # mkfs.xfs -f -bsize=4096 -dagsize=76288719b,size=3905982455b fsfile
 # mount -o loop fsfile /mnt
 # xfs_growfs /mnt

meta-data=/dev/loop0             isize=256    agcount=52,
agsize=76288719 blks
         =                       sectsz=512   attr=2
data     =                       bsize=4096   blocks=3905982455, imaxpct=5
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0
log      =internal               bsize=4096   blocks=32768, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=0
realtime =none                   extsz=4096   blocks=0, rtextents=0
xfs_growfs: XFS_IOC_FSGROWFSDATA xfsctl failed: Invalid argument

Reported-by: richard.ems@cape-horn-eng.com
Signed-off-by: default avatarEric Sandeen <sandeen@sandeen.net>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarFelix Blyakher <felixb@sgi.com>
Signed-off-by: default avatarFelix Blyakher <felixb@sgi.com>
parent 1f23920d
...@@ -160,7 +160,7 @@ xfs_growfs_data_private( ...@@ -160,7 +160,7 @@ xfs_growfs_data_private(
nagcount = new + (nb_mod != 0); nagcount = new + (nb_mod != 0);
if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) { if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
nagcount--; nagcount--;
nb = nagcount * mp->m_sb.sb_agblocks; nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
if (nb < mp->m_sb.sb_dblocks) if (nb < mp->m_sb.sb_dblocks)
return XFS_ERROR(EINVAL); return XFS_ERROR(EINVAL);
} }
......
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