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 <[email protected]> --- 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
