Factor out a helper that does filemap_write_and_wait_range for the range
covered by a read kiocb, or returns -EAGAIN if the kiocb is marked as
nowait and there would be pages to write.
Signed-off-by: Christoph Hellwig
Reviewed-by: Damien Le Moal
Acked-by: Darrick J. Wong
---
block/fops.c| 18 +++---
include/linux/pagemap.h | 2 ++
mm/filemap.c| 30 ++
3 files changed, 23 insertions(+), 27 deletions(-)
diff --git a/block/fops.c b/block/fops.c
index 58d0aebc7313a8..575171049c5d83 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -576,21 +576,9 @@ static ssize_t blkdev_read_iter(struct kiocb *iocb, struct
iov_iter *to)
goto reexpand; /* skip atime */
if (iocb->ki_flags & IOCB_DIRECT) {
- struct address_space *mapping = iocb->ki_filp->f_mapping;
-
- if (iocb->ki_flags & IOCB_NOWAIT) {
- if (filemap_range_needs_writeback(mapping, pos,
- pos + count - 1)) {
- ret = -EAGAIN;
- goto reexpand;
- }
- } else {
- ret = filemap_write_and_wait_range(mapping, pos,
- pos + count - 1);
- if (ret < 0)
- goto reexpand;
- }
-
+ ret = kiocb_write_and_wait(iocb, count);
+ if (ret < 0)
+ goto reexpand;
file_accessed(iocb->ki_filp);
ret = blkdev_direct_IO(iocb, to);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index a56308a9d1a450..36fc2cea13ce20 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 write_inode_now(struct inode *, int sync);
int filemap_fdatawrite(struct address_space *);
int filemap_flush(struct address_space *);
@@ -54,6 +55,7 @@ int filemap_check_errors(struct address_space *mapping);
void __filemap_set_wb_err(struct address_space *mapping, int err);
int filemap_fdatawrite_wbc(struct address_space *mapping,
struct writeback_control *wbc);
+int kiocb_write_and_wait(struct kiocb *iocb, size_t count);
static inline int filemap_write_and_wait(struct address_space *mapping)
{
diff --git a/mm/filemap.c b/mm/filemap.c
index 15907af4a57ff5..5fcd5227f9cae2 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2762,6 +2762,21 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter
*iter,
}
EXPORT_SYMBOL_GPL(filemap_read);
+int kiocb_write_and_wait(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;
+
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (filemap_range_needs_writeback(mapping, pos, end))
+ return -EAGAIN;
+ return 0;
+ }
+
+ return filemap_write_and_wait_range(mapping, pos, end);
+}
+
/**
* generic_file_read_iter - generic filesystem read routine
* @iocb: kernel I/O control block
@@ -2797,18 +2812,9 @@ generic_file_read_iter(struct kiocb *iocb, struct
iov_iter *iter)
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
- if (iocb->ki_flags & IOCB_NOWAIT) {
- if (filemap_range_needs_writeback(mapping, iocb->ki_pos,
- iocb->ki_pos + count - 1))
- return -EAGAIN;
- } else {
- retval = filemap_write_and_wait_range(mapping,
- iocb->ki_pos,
- iocb->ki_pos + count - 1);
- if (retval < 0)
- return retval;
- }
-
+ retval = kiocb_write_and_wait(iocb, count);
+ if (retval < 0)
+ return retval;
file_accessed(file);
retval = mapping->a_ops->direct_IO(iocb, iter);
--
2.39.2
