From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
With dax we cannot deal with readpage() etc. So, we create a
funciton callback to perform the file data comparison and pass
it to generic_remap_file_range_prep() so it can use iomap-based
functions.
This may not be the best way to solve this. Suggestions welcome.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
---
fs/btrfs/ctree.h | 3 +++
fs/btrfs/dax.c | 7 +++++++
fs/btrfs/ioctl.c | 13 +++++++++++-
fs/dax.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/ocfs2/file.c | 2 +-
fs/read_write.c | 9 +++++---
fs/xfs/xfs_reflink.c | 2 +-
include/linux/dax.h | 2 ++
include/linux/fs.h | 4 +++-
9 files changed, 93 insertions(+), 7 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0e5060933bde..750f9c70fabe 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3803,6 +3803,9 @@ int btree_readahead_hook(struct extent_buffer *eb, int err);
ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to);
ssize_t btrfs_file_dax_write(struct kiocb *iocb, struct iov_iter *from);
vm_fault_t btrfs_dax_fault(struct vm_fault *vmf);
+int btrfs_dax_file_range_compare(struct inode *src, loff_t srcoff,
+ struct inode *dest, loff_t destoff, loff_t len,
+ bool *is_same);
#else
static inline ssize_t btrfs_file_dax_write(struct kiocb *iocb, struct iov_iter *from)
{
diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c
index 927f962d1e88..9488cae0f8b4 100644
--- a/fs/btrfs/dax.c
+++ b/fs/btrfs/dax.c
@@ -168,4 +168,11 @@ vm_fault_t btrfs_dax_fault(struct vm_fault *vmf)
return ret;
}
+
+int btrfs_dax_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, &btrfs_iomap_ops);
+}
#endif /* CONFIG_FS_DAX */
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index e66426e7692d..2e5137b01561 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3990,8 +3990,19 @@ static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
if (ret < 0)
goto out_unlock;
+#ifdef CONFIG_FS_DAX
+ if (IS_DAX(file_inode(file_in)) && IS_DAX(file_inode(file_out)))
+ ret = generic_remap_file_range_prep(file_in, pos_in, file_out,
+ pos_out, len, remap_flags,
+ btrfs_dax_file_range_compare);
+ else
+ ret = generic_remap_file_range_prep(file_in, pos_in, file_out,
+ pos_out, len, remap_flags, NULL);
+#else
ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
- len, remap_flags);
+ len, remap_flags, NULL);
+#endif
+
if (ret < 0 || *len == 0)
goto out_unlock;
diff --git a/fs/dax.c b/fs/dax.c
index 41061da42771..18998c5ee27a 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1775,3 +1775,61 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
return dax_insert_pfn_mkwrite(vmf, pfn, order);
}
EXPORT_SYMBOL_GPL(dax_finish_sync_fault);
+
+
+int dax_file_range_compare(struct inode *src, loff_t srcoff, struct inode *dest,
+ loff_t destoff, loff_t len, bool *is_same, const struct iomap_ops *ops)
+{
+ void *saddr, *daddr;
+ struct iomap s_iomap = {0};
+ struct iomap d_iomap = {0};
+ loff_t dstart, sstart;
+ bool same = true;
+ loff_t cmp_len, l;
+ int id, ret = 0;
+
+ id = dax_read_lock();
+ while (len) {
+ ret = ops->iomap_begin(src, srcoff, len, 0, &s_iomap);
+ if (ret < 0) {
+ if (ops->iomap_end)
+ ops->iomap_end(src, srcoff, len, ret, 0, &s_iomap);
+ return ret;
+ }
+ cmp_len = len;
+ if (cmp_len > s_iomap.offset + s_iomap.length - srcoff)
+ cmp_len = s_iomap.offset + s_iomap.length - srcoff;
+
+ ret = ops->iomap_begin(dest, destoff, cmp_len, 0, &d_iomap);
+ if (ret < 0) {
+ if (ops->iomap_end) {
+ ops->iomap_end(src, srcoff, len, ret, 0, &s_iomap);
+ ops->iomap_end(dest, destoff, len, ret, 0, &d_iomap);
+ }
+ return ret;
+ }
+ if (cmp_len > d_iomap.offset + d_iomap.length - destoff)
+ cmp_len = d_iomap.offset + d_iomap.length - destoff;
+
+
+ sstart = (get_start_sect(s_iomap.bdev) << 9) + s_iomap.addr + (srcoff - s_iomap.offset);
+ l = dax_direct_access(s_iomap.dax_dev, PHYS_PFN(sstart), PHYS_PFN(cmp_len), &saddr, NULL);
+ dstart = (get_start_sect(d_iomap.bdev) << 9) + d_iomap.addr + (destoff - d_iomap.offset);
+ l = dax_direct_access(d_iomap.dax_dev, PHYS_PFN(dstart), PHYS_PFN(cmp_len), &daddr, NULL);
+ same = !memcmp(saddr, daddr, cmp_len);
+ if (!same)
+ break;
+ len -= cmp_len;
+ srcoff += cmp_len;
+ destoff += cmp_len;
+
+ if (ops->iomap_end) {
+ ret = ops->iomap_end(src, srcoff, len, 0, 0, &s_iomap);
+ ret = ops->iomap_end(dest, destoff, len, 0, 0, &d_iomap);
+ }
+ }
+ dax_read_unlock(id);
+ *is_same = same;
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dax_file_range_compare);
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index d640c5f8a85d..6bf3e8fbb016 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2558,7 +2558,7 @@ static loff_t ocfs2_remap_file_range(struct file *file_in, loff_t pos_in,
goto out_unlock;
ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
- &len, remap_flags);
+ &len, remap_flags, NULL);
if (ret < 0 || len == 0)
goto out_unlock;
diff --git a/fs/read_write.c b/fs/read_write.c
index 177ccc3d405a..da521a221213 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1855,7 +1855,7 @@ static int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
*/
int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
- loff_t *len, unsigned int remap_flags)
+ loff_t *len, unsigned int remap_flags, compare_range_t compare)
{
struct inode *inode_in = file_inode(file_in);
struct inode *inode_out = file_inode(file_out);
@@ -1914,8 +1914,11 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
*/
if (remap_flags & REMAP_FILE_DEDUP) {
bool is_same = false;
-
- ret = vfs_dedupe_file_range_compare(inode_in, pos_in,
+ if (compare)
+ ret = compare(inode_in, pos_in,
+ inode_out, pos_out, *len, &is_same);
+ else
+ ret = vfs_dedupe_file_range_compare(inode_in, pos_in,
inode_out, pos_out, *len, &is_same);
if (ret)
return ret;
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 680ae7662a78..8907c7aa3f19 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1350,7 +1350,7 @@ xfs_reflink_remap_prep(
goto out_unlock;
ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
- len, remap_flags);
+ len, remap_flags, NULL);
if (ret < 0 || *len == 0)
goto out_unlock;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 0dd316a74a29..a11bc7b1f526 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -157,6 +157,8 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
+int dax_file_range_compare(struct inode *src, loff_t srcoff, struct inode *dest,
+ loff_t destoff, loff_t len, bool *is_same, const struct iomap_ops *ops);
#ifdef CONFIG_FS_DAX
int __dax_zero_page_range(struct block_device *bdev,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8b42df09b04c..22fe4324b22e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1880,10 +1880,12 @@ extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
unsigned long, loff_t *, rwf_t);
extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
loff_t, size_t, unsigned int);
+typedef int (compare_range_t)(struct inode *src, loff_t srcpos, struct inode *dest,
+ loff_t destpos, loff_t len, bool *is_same);
extern int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
loff_t *count,
- unsigned int remap_flags);
+ unsigned int remap_flags, compare_range_t cmp);
extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
loff_t len, unsigned int remap_flags);
--
2.16.4
