From 69f4a26c1e0c7c5e5e77c5bd7b271743c124c545 Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Tue, 3 Aug 2021 09:38:22 -0700 Subject: iomap: support reading inline data from non-zero pos The existing inline data support only works for cases where the entire file is stored as inline data. For larger files, EROFS stores the initial blocks separately and the remainder of the file ("file tail") adjacent to the inode. Generalise inline data to allow reading the inline file tail. Tails may not cross a page boundary in memory. We currently have no filesystems that support tails and writing, so that case is currently disabled (see iomap_write_begin_inline). Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Reviewed-by: Matthew Wilcox (Oracle) Signed-off-by: Andreas Gruenbacher Signed-off-by: Gao Xiang Signed-off-by: Darrick J. Wong --- fs/iomap/direct-io.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'fs/iomap/direct-io.c') diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 9398b8c31323..41ccbfc9dc82 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -378,23 +378,25 @@ 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; + void *inline_data = iomap_inline_data(iomap, pos); size_t copied; - BUG_ON(pos + length > PAGE_SIZE - offset_in_page(iomap->inline_data)); + if (WARN_ON_ONCE(!iomap_inline_data_valid(iomap))) + return -EIO; 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); + memset(iomap_inline_data(iomap, size), 0, pos - size); + copied = copy_from_iter(inline_data, 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); + copied = copy_to_iter(inline_data, length, iter); } dio->size += copied; return copied; -- cgit v1.2.3