Add a callback to iomap_file_buffered_write that's called whenever
writing to a page has completed. This is needed for implementing data
journaling: in the data journaling case, pages are written into the
journal before being written back to their proper on-disk locations.
(So far, the only user of iomap_file_buffered_write is xfs, which
doesn't do data journaling.)
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/iomap.c | 21 +++++++++++++++++++--
include/linux/iomap.h | 9 +++++++++
2 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/fs/iomap.c b/fs/iomap.c
index 47d29ccffaef..98903be66c35 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -149,11 +149,21 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
return ret;
}
+struct iomap_write_data {
+ struct iov_iter *iter;
+ const struct iomap_ops *ops;
+};
+
static loff_t
iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct iomap *iomap)
{
- struct iov_iter *i = data;
+ struct iomap_write_data *d = data;
+ struct iov_iter *i = d->iter;
+ void (*iomap_written)(struct inode *inode, struct page *page,
+ unsigned int offset, unsigned int length,
+ unsigned int written) =
+ d->ops->iomap_written;
long status = 0;
ssize_t written = 0;
unsigned int flags = AOP_FLAG_NOFS;
@@ -198,6 +208,9 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
flush_dcache_page(page);
+ if (iomap_written)
+ iomap_written(inode, page, offset, bytes, copied);
+
status = iomap_write_end(inode, pos, bytes, copied, page);
if (unlikely(status < 0))
break;
@@ -235,10 +248,14 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *iter,
{
struct inode *inode = iocb->ki_filp->f_mapping->host;
loff_t pos = iocb->ki_pos, ret = 0, written = 0;
+ struct iomap_write_data data = {
+ .iter = iter,
+ .ops = ops,
+ };
while (iov_iter_count(iter)) {
ret = iomap_apply(inode, pos, iov_iter_count(iter),
- IOMAP_WRITE, ops, iter, iomap_write_actor);
+ IOMAP_WRITE, ops, &data, iomap_write_actor);
if (ret <= 0)
break;
pos += ret;
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 19a07de28212..042b8c8df44b 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -61,6 +61,8 @@ struct iomap {
#define IOMAP_DIRECT (1 << 4) /* direct I/O */
#define IOMAP_NOWAIT (1 << 5) /* Don't wait for writeback */
+struct page;
+
struct iomap_ops {
/*
* Return the existing mapping at pos, or reserve space starting at
@@ -70,6 +72,13 @@ struct iomap_ops {
int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, struct iomap *iomap);
+ /*
+ * Called after writing to a page has completed.
+ */
+ void (*iomap_written)(struct inode *inode, struct page *page,
+ unsigned int offset, unsigned int length,
+ unsigned int written);
+
/*
* Commit and/or unreserve space previous allocated using iomap_begin.
* Written indicates the length of the successful write operation which
--
2.14.3
