ext4: add new online resize interface

This patch adds new online resize interface, whose input argument is a
64-bit integer indicating how many blocks there are in the resized fs.

In new resize impelmentation, all work like allocating group tables
are done by kernel side, so the new resize interface can support
flex_bg feature and prepares ground for suppoting resize with features
like bigalloc and exclude bitmap. Besides these, user-space tools just
passes in the new number of blocks.

We delay initializing the bitmaps and inode tables of added groups if
possible and add multi groups (a flex groups) each time, so new resize
is very fast like mkfs.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Yongqiang Yang
2012-01-04 17:09:44 -05:00
committed by Theodore Ts'o
parent 4bac1f8cef
commit 19c5246d25
4 changed files with 243 additions and 0 deletions

View File

@@ -581,6 +581,13 @@ Table of Ext4 specific ioctls
behaviour may change in the future as it is
not necessary and has been done this way only
for sake of simplicity.
EXT4_IOC_RESIZE_FS Resize the filesystem to a new size. The number
of blocks of resized filesystem is passed in via
64 bit integer argument. The kernel allocates
bitmaps and inode table, the userspace tool thus
just passes the new number of blocks.
..............................................................................
References