ext4: Take page lock before looking at attached buffer_heads flags
ext4: Take page lock before looking at attached buffer_heads flags

In order to check whether the buffer_heads are mapped we need to hold
page lock. Otherwise a reclaim can cleanup the attached buffer_heads.

Signed-off-by: Aneesh Kumar K.V <f511f818e8a0748edef6b9ee378967da9ed0c78f@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <4ed386e0495d3e109932df055831d9ec2f824927@mit.edu>

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