Hi all,
V2->V3:
initialize block bitmap of last group.
remove code initalizing inode bitmap and inode tables.
This patch series adds new resize implementation to ext4.
-- What's new resize implementation?
It is a new online resize interface for ext4. It can be used via
ioctl with EXT4_IOC_RESIZE_FS and a 64 bit integer indicating size
of the resized fs in block.
-- Difference between current resize and new resize.
New resize lets kernel do all work, like allocating bitmaps and
inode tables and can support flex_bg and BLOCK_UNINIT features.
Besides these, new resize is much faster than current resize.
Below are benchmarks I made on my personal computer, fses with
flex_bg size = 16 were resized to 230GB evry time. The first
row shows the size of a fs from which the fs was resized to 230GB.
The datas were collected by 'time resize2fs'.
new resize
20GB 50GB 100GB
real 0m3.558s 0m2.891s 0m0.394s
user 0m0.004s 0m0.000s 0m0.394s
sys 0m0.048s 0m0.048s 0m0.028s
current resize
20GB 50GB 100GB
real 5m2.770s 4m43.757s 3m14.840s
user 0m0.040s 0m0.032s 0m0.024s
sys 0m0.464s 0m0.432s 0m0.324s
According to data above, new resize is faster than current resize in both
user and sys time. New resize performs well in sys time, because it
supports BLOCK_UNINIT and adds multi-groups each time.
-- About supporting new features.
YES! New resize can support new feature like bigalloc and exclude bitmap
easily. Because it lets kernel do all work.
Yongqiang.
git diff --stat
Documentation/filesystems/ext4.txt | 7 +
fs/ext4/ext4.h | 10 +
fs/ext4/ioctl.c | 39 ++
fs/ext4/resize.c | 1167 +++++++++++++++++++++++++++---------
4 files changed, 942 insertions(+), 281 deletions(-)
[PATCH V3 01/15] ext4: add a function which extends a group without
[PATCH V3 02/15] ext4: add a function which adds a new desc to a fs
[PATCH V3 03/15] ext4: add a function which sets up a new group desc
[PATCH V3 04/15] ext4: add a function which updates super block
[PATCH V3 05/15] ext4: add a structure which will be used by
[PATCH V3 06/15] ext4: add a function which sets up group blocks of
[PATCH V3 07/15] ext4: add a function which adds several group
[PATCH V3 08/15] ext4: add a function which sets up a flex groups
[PATCH V3 09/15] ext4: enable ext4_update_super() to handle a flex
[PATCH V3 10/15] ext4: pass verify_reserved_gdb() the number of
[PATCH V3 11/15] ext4: add a new function which allocates bitmaps
[PATCH V3 12/15] ext4: add a new function which adds a flex group to
[PATCH V3 13/15] ext4: add new online resize interface
[PATCH V3 14/15] ext4: let ext4_group_extend() use common code
[PATCH V3 15/15] ext4: let ext4_group_add() use common code
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