On 06/20, Jens Axboe wrote:
> a_ops->readpages() is only ever used for read-ahead, yet we don't
> flag the IO being submitted as such. Fix that up. Any file system
> that uses mpage_readpages() as its ->readpages() implementation
> will now get this right.
>
> Since we're passing in whether the IO is read-ahead or not, we
> don't need to pass in the 'gfp' separately, as it is dependent
> on the IO being read-ahead. Kill off that member.
>
> Add some documentation notes on ->readpages() being purely for
> read-ahead.
>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> ---
> fs/f2fs/data.c | 5 +++++
> fs/mpage.c | 29 +++++++++++++++++++----------
> include/linux/fs.h | 4 ++++
> 3 files changed, 28 insertions(+), 10 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 8f931d699287..b7c9b58acf3e 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -1421,6 +1421,11 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> /*
> * This function was originally taken from fs/mpage.c, and customized for f2fs.
> * Major change was from block_size == page_size in f2fs by default.
> + *
> + * Note that the aops->readpages() function is ONLY used for read-ahead. If
> + * this function ever deviates from doing just read-ahead, it should either
> + * use ->readpage() or do the necessary surgery to decouple ->readpages()
> + * readom read-ahead.
> */
> static int f2fs_mpage_readpages(struct address_space *mapping,
> struct list_head *pages, struct page *page,
Hi Jens,
Could you please consider the below change to address your concern?
---
fs/f2fs/data.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 8f931d699287..c1266b231f62 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -534,7 +534,7 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
}
static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
- unsigned nr_pages)
+ unsigned nr_pages, unsigned op_flag)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct bio *bio;
@@ -546,7 +546,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
return ERR_PTR(-ENOMEM);
f2fs_target_device(sbi, blkaddr, bio);
bio->bi_end_io = f2fs_read_end_io;
- bio_set_op_attrs(bio, REQ_OP_READ, 0);
+ bio_set_op_attrs(bio, REQ_OP_READ, op_flag);
if (f2fs_encrypted_file(inode))
post_read_steps |= 1 << STEP_DECRYPT;
@@ -571,7 +571,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
static int f2fs_submit_page_read(struct inode *inode, struct page *page,
block_t blkaddr)
{
- struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1);
+ struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1, 0);
if (IS_ERR(bio))
return PTR_ERR(bio);
@@ -1424,7 +1424,7 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
*/
static int f2fs_mpage_readpages(struct address_space *mapping,
struct list_head *pages, struct page *page,
- unsigned nr_pages)
+ unsigned nr_pages, bool is_readahead)
{
struct bio *bio = NULL;
sector_t last_block_in_bio = 0;
@@ -1514,7 +1514,8 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
bio = NULL;
}
if (bio == NULL) {
- bio = f2fs_grab_read_bio(inode, block_nr, nr_pages);
+ bio = f2fs_grab_read_bio(inode, block_nr, nr_pages,
+ is_readahead ? REQ_RAHEAD : 0);
if (IS_ERR(bio)) {
bio = NULL;
goto set_error_page;
@@ -1558,7 +1559,7 @@ static int f2fs_read_data_page(struct file *file, struct page *page)
if (f2fs_has_inline_data(inode))
ret = f2fs_read_inline_data(inode, page);
if (ret == -EAGAIN)
- ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
+ ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1, false);
return ret;
}
@@ -1575,7 +1576,7 @@ static int f2fs_read_data_pages(struct file *file,
if (f2fs_has_inline_data(inode))
return 0;
- return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
+ return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages, true);
}
static int encrypt_one_page(struct f2fs_io_info *fio)
--
2.17.0.441.gb46fe60e1d-goog
