How to increase space allocated to inode in XFS filesystem

We are facing a problem with a ceph osd node which uses an XFS file system.
The mount has become non-writeable. It gives the following error:

root@fab-prod-ceph-h3:/var/lib/ceph/osd/ceph-6# touch hrushi  

touch: cannot touch `hrushi': No space left on device

Both, df -i and df -h, indicate a consumption of about ~40%.

Here is the output:

Filesystem                          Inodes    IUsed     IFree IUse% Mounted on
/dev/sda2                        178921472    60895 178860577    1% /
udev                               8240393      597   8239796    1% /dev
tmpfs                              8242709      582   8242127    1% /run
none                               8242709        3   8242706    1% /run/lock
none                               8242709        1   8242708    1% /run/shm
/dev/sdd1                         73111872 25981652  47130220   36% /var/lib/ceph/osd/ceph-8
/dev/sdc1                         73111872 30445183  42666689   42% /var/lib/ceph/osd/ceph-7
/dev/sde1                         97530624  1913758  95616866    2% /var/lib/ceph/osd/ceph-15
/dev/sdf1                         97530624  2680246  94850378    3% /var/lib/ceph/osd/ceph-16
/dev/sdg1                        195206272  2206318 192999954    2% /var/lib/ceph/osd/ceph-17
/dev/sdb1                        146223870 33812416 112411454   24% /var/lib/ceph/osd/ceph-6
10.100.112.53:/srv/data/Alcatraz  98304000 15954028  82349972   17% /exporter

root@fab-prod-ceph-h3:/var/lib/ceph/osd/ceph-6# df -h
Filesystem                        Size  Used Avail Use% Mounted on
/dev/sda2                         2.7T  313G  2.2T  13% /
udev                               32G   12K   32G   1% /dev
tmpfs                              13G  364K   13G   1% /run
none                              5.0M     0  5.0M   0% /run/lock
none                               32G     0   32G   0% /run/shm
/dev/sdd1                         2.8T  1.8T 1010G  64% /var/lib/ceph/osd/ceph-8
/dev/sdc1                         2.8T  1.7T  1.2T  60% /var/lib/ceph/osd/ceph-7
/dev/sde1                         3.7T  158G  3.5T   5% /var/lib/ceph/osd/ceph-15
/dev/sdf1                         3.7T  185G  3.5T   5% /var/lib/ceph/osd/ceph-16
/dev/sdg1                         7.3T  155G  7.2T   3% /var/lib/ceph/osd/ceph-17
/dev/sdb1                         2.8T  1.9T  937G  67% /var/lib/ceph/osd/ceph-6
10.100.112.53:/srv/data/Alcatraz  1.5T  901G  502G  65% /exporter

A few community forum postings suggested increasing the space allocated to save inodes.

Initial:

root@fab-prod-ceph-h3:/var/lib/ceph/osd/ceph-6# xfs_info /dev/sdb1
meta-data=/dev/sdb1              isize=2048   agcount=32, agsize=22847480 blks
         =                       sectsz=512   attr=2
data     =                       bsize=4096   blocks=731119355, imaxpct=5
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0
log      =internal               bsize=4096   blocks=356991, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Extended

root@fab-prod-ceph-h3:/var/lib/ceph/osd/ceph-6# xfs_growfs -m 10 /var/lib/ceph/osd/ceph-6
meta-data=/dev/sdb1              isize=2048   agcount=32, agsize=22847480 blks
         =                       sectsz=512   attr=2
data     =                       bsize=4096   blocks=731119355, imaxpct=5
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0
log      =internal               bsize=4096   blocks=356991, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
inode max percent changed from 5 to 10

root@fab-prod-ceph-h3:/var/lib/ceph/osd/ceph-6# xfs_db -f -c "sb 0" -c "p" /dev/sdb1 | grep imax_pct
imax_pct = 5

Note:
This value did not change.

How do I resolve this problem?

I have tried upgrading the kernel version from 3.5 to 3.15 as well, but without success.