In fsdax mode, WRITE and ZERO on a shared extent need CoW performed.
After that, new allocated extents needs to be remapped to the file.
So, add a CoW identification in ->iomap_begin(), and implement
->iomap_end() to do the remapping work.
Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
fs/xfs/xfs_file.c | 33 ++++++++++++++++++++++++++++-----
fs/xfs/xfs_iomap.c | 30 +++++++++++++++++++++++++++++-
fs/xfs/xfs_iomap.h | 1 +
3 files changed, 58 insertions(+), 6 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index af954a5b71f8..fe9f92586acf 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -25,6 +25,7 @@
#include "xfs_iomap.h"
#include "xfs_reflink.h"
+#include <linux/dax.h>
#include <linux/falloc.h>
#include <linux/backing-dev.h>
#include <linux/mman.h>
@@ -669,7 +670,7 @@ xfs_file_dax_write(
pos = iocb->ki_pos;
trace_xfs_file_dax_write(iocb, from);
- ret = dax_iomap_rw(iocb, from, &xfs_direct_write_iomap_ops);
+ ret = dax_iomap_rw(iocb, from, &xfs_dax_write_iomap_ops);
if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
i_size_write(inode, iocb->ki_pos);
error = xfs_setfilesize(ip, pos, ret);
@@ -1254,6 +1255,31 @@ xfs_file_llseek(
return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
}
+#ifdef CONFIG_FS_DAX
+int
+xfs_dax_fault(
+ struct vm_fault *vmf,
+ enum page_entry_size pe_size,
+ bool write_fault,
+ pfn_t *pfn)
+{
+ return dax_iomap_fault(vmf, pe_size, pfn, NULL,
+ (write_fault && !vmf->cow_page) ?
+ &xfs_dax_write_iomap_ops :
+ &xfs_read_iomap_ops);
+}
+#else
+int
+xfs_dax_fault(
+ struct vm_fault *vmf,
+ enum page_entry_size pe_size,
+ bool write_fault,
+ pfn_t *pfn)
+{
+ return 0;
+}
+#endif
+
/*
* Locking for serialisation of IO during page faults. This results in a lock
* ordering of:
@@ -1285,10 +1311,7 @@ __xfs_filemap_fault(
pfn_t pfn;
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
- ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL,
- (write_fault && !vmf->cow_page) ?
- &xfs_direct_write_iomap_ops :
- &xfs_read_iomap_ops);
+ ret = xfs_dax_fault(vmf, pe_size, write_fault, &pfn);
if (ret & VM_FAULT_NEEDDSYNC)
ret = dax_finish_sync_fault(vmf, pe_size, pfn);
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 5a393259a3a3..4c07f5e718fb 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -773,7 +773,8 @@ xfs_direct_write_iomap_begin(
/* may drop and re-acquire the ilock */
error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared,
- &lockmode, flags & IOMAP_DIRECT);
+ &lockmode,
+ (flags & IOMAP_DIRECT) || IS_DAX(inode));
if (error)
goto out_unlock;
if (shared)
@@ -867,6 +868,33 @@ const struct iomap_ops xfs_direct_write_iomap_ops = {
.iomap_begin = xfs_direct_write_iomap_begin,
};
+static int
+xfs_dax_write_iomap_end(
+ struct inode *inode,
+ loff_t pos,
+ loff_t length,
+ ssize_t written,
+ unsigned flags,
+ struct iomap *iomap)
+{
+ struct xfs_inode *ip = XFS_I(inode);
+
+ if (!xfs_is_cow_inode(ip))
+ return 0;
+
+ if (!written) {
+ xfs_reflink_cancel_cow_range(ip, pos, length, true);
+ return 0;
+ }
+
+ return xfs_reflink_end_cow(ip, pos, written);
+}
+
+const struct iomap_ops xfs_dax_write_iomap_ops = {
+ .iomap_begin = xfs_direct_write_iomap_begin,
+ .iomap_end = xfs_dax_write_iomap_end,
+};
+
static int
xfs_buffered_write_iomap_begin(
struct inode *inode,
diff --git a/fs/xfs/xfs_iomap.h b/fs/xfs/xfs_iomap.h
index e88dc162c785..c782e8c0479c 100644
--- a/fs/xfs/xfs_iomap.h
+++ b/fs/xfs/xfs_iomap.h
@@ -51,5 +51,6 @@ extern const struct iomap_ops xfs_direct_write_iomap_ops;
extern const struct iomap_ops xfs_read_iomap_ops;
extern const struct iomap_ops xfs_seek_iomap_ops;
extern const struct iomap_ops xfs_xattr_iomap_ops;
+extern const struct iomap_ops xfs_dax_write_iomap_ops;
#endif /* __XFS_IOMAP_H__*/
--
2.35.1
