From 076171a67789ad0107de44c2964f2e46a7d0d7b8 Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Fri, 14 May 2021 17:27:30 -0700
Subject: [PATCH] mm/filemap: fix readahead return types
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.
Link: https://lkml.kernel.org/r/20210510201201.1558972-1-willy@infradead.org
Fixes: 32c0a6bcaa1f57 ("btrfs: add and use readahead_batch_length")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
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 f2cd2034a87bb..9023717c5188b 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 a4bd41128bf31..e89df447fae32 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;
}
--
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