xfs: add dedupe range vfs function
Define a VFS function which allows userspace to request that the
kernel reflink a range of blocks between two files if the ranges'
contents match. The function fits the new VFS ioctl that standardizes
the checking for the btrfs EXTENT SAME ioctl.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index cf24b61..39fde9f 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1010,7 +1010,8 @@
loff_t pos_in,
struct file *file_out,
loff_t pos_out,
- u64 len)
+ u64 len,
+ bool is_dedupe)
{
struct inode *inode_in;
struct inode *inode_out;
@@ -1019,6 +1020,7 @@
loff_t isize;
int same_inode;
loff_t blen;
+ unsigned int flags = 0;
inode_in = file_inode(file_in);
inode_out = file_inode(file_out);
@@ -1056,6 +1058,15 @@
pos_in + len > isize)
return -EINVAL;
+ /* Don't allow dedupe past EOF in the dest file */
+ if (is_dedupe) {
+ loff_t disize;
+
+ disize = i_size_read(inode_out);
+ if (pos_out >= disize || pos_out + len > disize)
+ return -EINVAL;
+ }
+
/* If we're linking to EOF, continue to the block boundary. */
if (pos_in + len == isize)
blen = ALIGN(isize, bs) - pos_in;
@@ -1079,8 +1090,10 @@
if (ret)
goto out_unlock;
+ if (is_dedupe)
+ flags |= XFS_REFLINK_DEDUPE;
ret = xfs_reflink_remap_range(XFS_I(inode_in), pos_in, XFS_I(inode_out),
- pos_out, len);
+ pos_out, len, flags);
if (ret < 0)
goto out_unlock;
@@ -1100,7 +1113,7 @@
int error;
error = xfs_file_share_range(file_in, pos_in, file_out, pos_out,
- len);
+ len, false);
if (error)
return error;
return len;
@@ -1115,7 +1128,33 @@
u64 len)
{
return xfs_file_share_range(file_in, pos_in, file_out, pos_out,
- len);
+ len, false);
+}
+
+#define XFS_MAX_DEDUPE_LEN (16 * 1024 * 1024)
+STATIC ssize_t
+xfs_file_dedupe_range(
+ struct file *src_file,
+ u64 loff,
+ u64 len,
+ struct file *dst_file,
+ u64 dst_loff)
+{
+ int error;
+
+ /*
+ * Limit the total length we will dedupe for each operation.
+ * This is intended to bound the total time spent in this
+ * ioctl to something sane.
+ */
+ if (len > XFS_MAX_DEDUPE_LEN)
+ len = XFS_MAX_DEDUPE_LEN;
+
+ error = xfs_file_share_range(src_file, loff, dst_file, dst_loff,
+ len, true);
+ if (error)
+ return error;
+ return len;
}
STATIC int
@@ -1779,6 +1818,7 @@
.fallocate = xfs_file_fallocate,
.copy_file_range = xfs_file_copy_range,
.clone_file_range = xfs_file_clone_range,
+ .dedupe_file_range = xfs_file_dedupe_range,
};
const struct file_operations xfs_dir_file_operations = {