On 6/21/18 12:47 PM, Jaegeuk Kim wrote: > 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? Looks good to me. -- Jens Axboe