Add support for reading from and writing to inline data to iomap_dio_rw.
This saves filesystems from having to implement fallback code for this
case.
The inline data is actually cached in the inode, so the I/O is only
direct in the sense that it doesn't go through the page cache. The same
alignment restrictions as to non-inline data apply.
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/iomap.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/fs/iomap.c b/fs/iomap.c
index d393bb0c7384..74668b3ca2ed 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1231,6 +1231,32 @@ iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos,
return submit_bio(bio);
}
+static loff_t iomap_dio_actor_inline(struct inode *inode, struct iomap_dio *dio,
+ struct iomap *iomap, loff_t pos, loff_t length)
+{
+ struct iov_iter *iter = dio->submit.iter;
+ size_t copied;
+
+ BUG_ON(pos + length > PAGE_SIZE - offset_in_page(iomap->inline_data));
+
+ if (dio->flags & IOMAP_DIO_WRITE) {
+ loff_t size = inode->i_size;
+
+ if (pos > size)
+ memset(iomap->inline_data + size, 0, pos - size);
+ copied = copy_from_iter(iomap->inline_data + pos, length, iter);
+ if (copied) {
+ if (pos + copied > size)
+ i_size_write(inode, pos + copied);
+ mark_inode_dirty(inode);
+ }
+ } else {
+ copied = copy_to_iter(iomap->inline_data + pos, length, iter);
+ }
+ dio->size += copied;
+ return copied;
+}
+
static loff_t
iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
void *data, struct iomap *iomap)
@@ -1281,6 +1307,8 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
use_fua = true;
}
break;
+ case IOMAP_INLINE:
+ return iomap_dio_actor_inline(inode, dio, iomap, pos, length);
default:
WARN_ON_ONCE(1);
return -EIO;
--
2.17.1
