Re: [PATCH] mm/filemap: Fix readahead return types
From: "Darrick J. Wong" <djwong@kernel.org>
Date: 2021-05-10 22:27:58
Also in:
linux-btrfs, linux-fsdevel, linux-xfs
On Mon, May 10, 2021 at 09:12:01PM +0100, Matthew Wilcox (Oracle) wrote:
A readahead request will not allocate more memory than can be represented by a size_t, even on systems that have HIGHMEM available. Change the length functions from returning an loff_t to a size_t. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Looks reasonable to me; is this a 5.13 bugfix or just something that doesn't look right (i.e. save it for 5.14)? Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D
quoted hunk ↗ jump to hunk
--- fs/iomap/buffered-io.c | 4 ++-- include/linux/pagemap.h | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-)diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index f2cd2034a87b..9023717c5188 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c@@ -394,7 +394,7 @@ void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops) { struct inode *inode = rac->mapping->host; loff_t pos = readahead_pos(rac); - loff_t length = readahead_length(rac); + size_t length = readahead_length(rac); struct iomap_readpage_ctx ctx = { .rac = rac, };@@ -402,7 +402,7 @@ void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops) trace_iomap_readahead(inode, readahead_count(rac)); while (length > 0) { - loff_t ret = iomap_apply(inode, pos, length, 0, ops, + ssize_t ret = iomap_apply(inode, pos, length, 0, ops, &ctx, iomap_readahead_actor); if (ret <= 0) { WARN_ON_ONCE(ret == 0);diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index a4bd41128bf3..e89df447fae3 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h@@ -997,9 +997,9 @@ static inline loff_t readahead_pos(struct readahead_control *rac) * readahead_length - The number of bytes in this readahead request. * @rac: The readahead request. */ -static inline loff_t readahead_length(struct readahead_control *rac) +static inline size_t readahead_length(struct readahead_control *rac) { - return (loff_t)rac->_nr_pages * PAGE_SIZE; + return rac->_nr_pages * PAGE_SIZE; } /**@@ -1024,7 +1024,7 @@ static inline unsigned int readahead_count(struct readahead_control *rac) * readahead_batch_length - The number of bytes in the current batch. * @rac: The readahead request. */ -static inline loff_t readahead_batch_length(struct readahead_control *rac) +static inline size_t readahead_batch_length(struct readahead_control *rac) { return rac->_batch_count * PAGE_SIZE; }-- 2.30.2