[PATCH 7/7] fs/xfs: Add dedupe support for fsdax

Shiyang Ruan
2021-02-07T17:09:50Z

Add xfs_break_two_dax_layouts() to break layout for tow dax files. Then
call compare range function only when files are both DAX or not.

Signed-off-by: Shiyang Ruan <ruansy.fnst@cn.fujitsu.com>
---
fs/xfs/xfs_file.c | 20 ++++++++++++++++++++
fs/xfs/xfs_inode.c | 8 +++++++-
fs/xfs/xfs_inode.h | 1 +
fs/xfs/xfs_reflink.c | 21 ++++++++++++++++++---
4 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index ab738641a3f4..64ded96b43c8 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -791,6 +791,26 @@ xfs_break_dax_layouts(
0, 0, xfs_wait_dax_page(inode));
}

+int
+xfs_break_two_dax_layouts(
+ struct inode *src,
+ struct inode *dest)
+{
+ int error;
+ bool retry = false;
+
+retry:
+ error = xfs_break_dax_layouts(src, &retry);
+ if (error || retry)
+ goto retry;
+
+ error = xfs_break_dax_layouts(dest, &retry);
+ if (error || retry)
+ goto retry;
+
+ return error;
+}
+
int
xfs_break_layouts(
struct inode *inode,
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 2bfbcf28b1bd..6483dbaa4d57 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3786,8 +3786,10 @@ xfs_ilock2_io_mmap(
struct xfs_inode *ip2)
{
int ret;
+ struct inode *inode1 = VFS_I(ip1);
+ struct inode *inode2 = VFS_I(ip2);

- ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
+ ret = xfs_iolock_two_inodes_and_break_layout(inode1, inode2);
if (ret)
return ret;
if (ip1 == ip2)
@@ -3795,6 +3797,10 @@ xfs_ilock2_io_mmap(
else
xfs_lock_two_inodes(ip1, XFS_MMAPLOCK_EXCL,
ip2, XFS_MMAPLOCK_EXCL);
+
+ if (IS_DAX(inode1) && IS_DAX(inode2))
+ ret = xfs_break_two_dax_layouts(inode1, inode2);
+
return 0;
}

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 751a3d1d7d84..462b61bea691 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -431,6 +431,7 @@ enum xfs_prealloc_flags {

int xfs_update_prealloc_flags(struct xfs_inode *ip,
enum xfs_prealloc_flags flags);
+int xfs_break_two_dax_layouts(struct inode *inode1, struct inode *inode2);
int xfs_break_layouts(struct inode *inode, uint *iolock,
enum layout_break_reason reason);

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 38bde16cdb39..bdb9a07e703f 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -29,6 +29,7 @@
#include "xfs_iomap.h"
#include "xfs_sb.h"
#include "xfs_ag_resv.h"
+#include <linux/dax.h>

/*
* Copy on Write of Shared Blocks
@@ -1251,6 +1252,14 @@ xfs_reflink_zero_posteof(
&xfs_buffered_write_iomap_ops);
}

+int xfs_reflink_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
+ struct inode *dest, loff_t destoff,
+ loff_t len, bool *is_same)
+{
+ return dax_file_range_compare(src, srcoff, dest, destoff, len, is_same,
+ &xfs_read_iomap_ops);
+}
+
/*
* Prepare two files for range cloning. Upon a successful return both inodes
* will have the iolock and mmaplock held, the page cache of the out file will
@@ -1293,6 +1302,7 @@ xfs_reflink_remap_prep(
struct xfs_inode *src = XFS_I(inode_in);
struct inode *inode_out = file_inode(file_out);
struct xfs_inode *dest = XFS_I(inode_out);
+ compare_range_t compare_range_fn;
int ret;

/* Lock both files against IO */
@@ -1306,12 +1316,17 @@ xfs_reflink_remap_prep(
if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
goto out_unlock;

- /* Don't share DAX file data for now. */
- if (IS_DAX(inode_in) || IS_DAX(inode_out))
+ /* Don't share DAX file data with non-DAX file. */
+ if (IS_DAX(inode_in) != IS_DAX(inode_out))
goto out_unlock;

+ if (IS_DAX(inode_in))
+ compare_range_fn = xfs_reflink_dedupe_file_range_compare;
+ else
+ compare_range_fn = vfs_dedupe_file_range_compare;
+
ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
- len, remap_flags, vfs_dedupe_file_range_compare);
+ len, remap_flags, compare_range_fn);
if (ret || *len == 0)
goto out_unlock;

--
2.30.0