Factor out a helper that calls filemap_write_and_wait_range and
invalidate_inode_pages2_range for the range covered by a write kiocb or
returns -EAGAIN if the kiocb is marked as nowait and there would be pages
to write or invalidate.
Signed-off-by: Christoph Hellwig <h...@lst.de>
Reviewed-by: Damien Le Moal <dlem...@kernel.org>
Acked-by: Darrick J. Wong <djw...@kernel.org>
---
include/linux/pagemap.h | 1 +
mm/filemap.c | 48 ++++++++++++++++++++++++-----------------
2 files changed, 29 insertions(+), 20 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 36fc2cea13ce20..6e4c9ee40baa99 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -30,6 +30,7 @@ static inline void invalidate_remote_inode(struct inode
*inode)
int invalidate_inode_pages2(struct address_space *mapping);
int invalidate_inode_pages2_range(struct address_space *mapping,
pgoff_t start, pgoff_t end);
+int kiocb_invalidate_pages(struct kiocb *iocb, size_t count);
int write_inode_now(struct inode *, int sync);
int filemap_fdatawrite(struct address_space *);
diff --git a/mm/filemap.c b/mm/filemap.c
index 5fcd5227f9cae2..a1cb01a4b8046a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2777,6 +2777,33 @@ int kiocb_write_and_wait(struct kiocb *iocb, size_t
count)
return filemap_write_and_wait_range(mapping, pos, end);
}
+int kiocb_invalidate_pages(struct kiocb *iocb, size_t count)
+{
+ struct address_space *mapping = iocb->ki_filp->f_mapping;
+ loff_t pos = iocb->ki_pos;
+ loff_t end = pos + count - 1;
+ int ret;
+
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ /* we could block if there are any pages in the range */
+ if (filemap_range_has_page(mapping, pos, end))
+ return -EAGAIN;
+ } else {
+ ret = filemap_write_and_wait_range(mapping, pos, end);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * After a write we want buffered reads to be sure to go to disk to get
+ * the new data. We invalidate clean cached page from the region we're
+ * about to write. We do this *before* the write so that we can return
+ * without clobbering -EIOCBQUEUED from ->direct_IO().
+ */
+ return invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT,
+ end >> PAGE_SHIFT);
+}
+
/**
* generic_file_read_iter - generic filesystem read routine
* @iocb: kernel I/O control block
@@ -3820,30 +3847,11 @@ generic_file_direct_write(struct kiocb *iocb, struct
iov_iter *from)
write_len = iov_iter_count(from);
end = (pos + write_len - 1) >> PAGE_SHIFT;
- if (iocb->ki_flags & IOCB_NOWAIT) {
- /* If there are pages to writeback, return */
- if (filemap_range_has_page(file->f_mapping, pos,
- pos + write_len - 1))
- return -EAGAIN;
- } else {
- written = filemap_write_and_wait_range(mapping, pos,
- pos + write_len - 1);
- if (written)
- goto out;
- }
-
- /*
- * After a write we want buffered reads to be sure to go to disk to get
- * the new data. We invalidate clean cached page from the region we're
- * about to write. We do this *before* the write so that we can return
- * without clobbering -EIOCBQUEUED from ->direct_IO().
- */
- written = invalidate_inode_pages2_range(mapping,
- pos >> PAGE_SHIFT, end);
/*
* If a page can not be invalidated, return 0 to fall back
* to buffered write.
*/
+ written = kiocb_invalidate_pages(iocb, write_len);
if (written) {
if (written == -EBUSY)
return 0;
--
2.39.2
