ext4: online defrag -- Add EXT4_IOC_MOVE_EXT ioctl
The EXT4_IOC_MOVE_EXT exchanges the blocks between orig_fd and donor_fd,
and then write the file data of orig_fd to donor_fd.
ext4_mext_move_extent() is the main fucntion of ext4 online defrag,
and this patch includes all functions related to ext4 online defrag.
Signed-off-by: Akira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index cc7d5ed..276a26f 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -352,6 +352,7 @@
/* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
/* 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)
/*
* ioctl commands in 32 bit emulation
@@ -447,6 +448,15 @@
__le32 i_version_hi; /* high 32 bits for 64-bit version */
};
+struct move_extent {
+ __u32 reserved; /* should be zero */
+ __u32 donor_fd; /* donor file descriptor */
+ __u64 orig_start; /* logical start offset in block for orig */
+ __u64 donor_start; /* logical start offset in block for donor */
+ __u64 len; /* block length to be moved */
+ __u64 moved_len; /* moved block length */
+};
+#define MAX_DEFRAG_SIZE ((1UL<<31) - 1)
#define EXT4_EPOCH_BITS 2
#define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
@@ -1647,6 +1657,11 @@
struct buffer_head *bh, int flags);
extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len);
+/* move_extent.c */
+extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
+ __u64 start_orig, __u64 start_donor,
+ __u64 len, __u64 *moved_len);
+
/*
* Add new method to test wether block and inode bitmaps are properly