Bug 15742

Summary: Fallocated extents handled incorrectly if beyond i_size
Product: File System Reporter: Dmitry Monakhov (dmonakhov)
Component: ext4Assignee: fs_ext4 (fs_ext4)
Status: RESOLVED CODE_FIX    
Severity: normal    
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: v2.6.25 Subsystem:
Regression: No Bisected commit-id:
Attachments: testcase

Description Dmitry Monakhov 2010-04-09 17:02:43 UTC 
bad commit: 3977c965ec35ce1a7eac988ad313f0fc9aee9660

Zerrout trick allow us to optimize cases where it is more reasonable
to explicitly zeroout extent and mark it as initialized instead of
splitting to several small ones.
But this optimization is not acceptable is extent is beyond i_size
Because it is not possible to have initialized blocks after i_size.
Fsck treat this as incorrect inode size.

#TESTCASE
mkfs.ext4 /dev/sdb1
mount /dev/sdb1 /mnt
./falloc_test /mnt/F1
umount /mnt
fsck.ext4 -f /dev/sdb1

fsck.ext4 -f /dev/sdb1
e2fsck 1.41.9 (22-Aug-2009)
Pass 1: Checking inodes, blocks, and sizes
Inode 12, i_size is 1, should be 40960.  Fix<y>? no
Comment 1 Dmitry Monakhov 2010-04-09 17:20:56 UTC 
Created attachment 25931 [details]
testcase
Comment 2 Dmitry Monakhov 2010-04-09 17:24:00 UTC 
Proposed patch:
http://patchwork.ozlabs.org/patch/49856/