xfs: fix overflow in xfs_growfs_data_private
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: ba7b249596404c7ffc875aa58cb7abe32487f8ae@cape-horn-eng.com
Signed-off-by: Eric Sandeen <d55521028c14e0f378be5444e4ea388161c0d7e7@sandeen.net>
Reviewed-by: Christoph Hellwig <923f7720577207a44b32e59bbfbea59d27f1ae8e@lst.de>
Reviewed-by: Felix Blyakher <489795e92d328beb2187b977cd7059f2eaf90933@sgi.com>
Signed-off-by: Felix Blyakher <489795e92d328beb2187b977cd7059f2eaf90933@sgi.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas