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>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 05058e2..4bc0e82 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -583,6 +583,7 @@
/* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
#define EXT4_IOC_ALLOC_DA_BLKS _IO('f', 12)
#define EXT4_IOC_MOVE_EXT _IOWR('f', 15, struct move_extent)
+#define EXT4_IOC_RESIZE_FS _IOW('f', 16, __u64)
#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/*
@@ -1929,6 +1930,7 @@
extern int ext4_group_extend(struct super_block *sb,
struct ext4_super_block *es,
ext4_fsblk_t n_blocks_count);
+extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
/* super.c */
extern void *ext4_kvmalloc(size_t size, gfp_t flags);