ext4: Return unwritten buffer head when trying to read from prealloc space.
authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tue, 29 Apr 2008 12:11:12 +0000 (08:11 -0400)
committerTheodore Ts'o <tytso@mit.edu>
Tue, 29 Apr 2008 12:11:12 +0000 (08:11 -0400)
commit1a89734d4057066344356e9c7e13b6379497aebe
tree7e0466cb367e3eb7aec72bdfd0c03aaa3e22449e
parente067ba0078cd6f00eb6c4052fec630b78ebe59de
ext4: Return unwritten buffer head when trying to read from prealloc space.

ext4_ext_get_blocks() returns the number of blocks allocated with buffer
head unmapped for a read from prealloc space.  This is needed so that
delayed allocation doesn't do block reservation for prealloc space
since the blocks are already reserved on disk.  Mark the buffer head
unwritten.  Some code paths try to read the block if the buffer_head is
not new and no uptodate.  Marking the buffer head unwritten avoids this
reading.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
fs/ext4/extents.c