From ec181f6782d8e8c22aa2c3462a20195cfa214ec6 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Tue, 3 Jul 2018 09:07:47 -0700 Subject: iomap: support direct I/O to inline data 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. Signed-off-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/iomap.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'fs/iomap.c') diff --git a/fs/iomap.c b/fs/iomap.c index 4d8ff0f5ecc9..98a1fdd5c091 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -1450,6 +1450,33 @@ iomap_dio_hole_actor(loff_t length, struct iomap_dio *dio) return length; } +static loff_t +iomap_dio_inline_actor(struct inode *inode, loff_t pos, loff_t length, + struct iomap_dio *dio, struct iomap *iomap) +{ + 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) @@ -1467,6 +1494,8 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length, return iomap_dio_bio_actor(inode, pos, length, dio, iomap); case IOMAP_MAPPED: return iomap_dio_bio_actor(inode, pos, length, dio, iomap); + case IOMAP_INLINE: + return iomap_dio_inline_actor(inode, pos, length, dio, iomap); default: WARN_ON_ONCE(1); return -EIO; -- cgit