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authorYongqiang Yang <xiaoqiangnk@gmail.com>2012-01-04 17:09:44 -0500
committerTheodore Ts'o <tytso@mit.edu>2012-01-04 17:09:44 -0500
commit19c5246d251640ac76daa4d34165af78c64b1454 (patch)
treecdf4f2250ca6b61d4910a3279d4d991486631d30 /Documentation/filesystems
parent4bac1f8cef7bfd2c62793f75aba66a5b8357dede (diff)
downloadop-kernel-dev-19c5246d251640ac76daa4d34165af78c64b1454.zip
op-kernel-dev-19c5246d251640ac76daa4d34165af78c64b1454.tar.gz
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>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/ext4.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 4917cf2..10ec4639 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -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.
+
..............................................................................
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