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authorMatthew Wilcox (Oracle) <willy@infradead.org>2023-05-20 12:13:20 -0400
committerMatthew Wilcox (Oracle) <willy@infradead.org>2023-07-24 18:04:30 -0400
commit5d8edfb900d55db7dbf2dbf325bfb9fdb863ec72 (patch)
tree97191965a56afcb9f875fcc8dfd44a1bec80136f
parentd6bb59a9444d218dc60dee3b45fd93c0d4f5e123 (diff)
iomap: Copy larger chunks from userspace
If we have a large folio, we can copy in larger chunks than PAGE_SIZE. Start at the maximum page cache size and shrink by half every time we hit the "we are short on memory" problem. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
-rw-r--r--fs/iomap/buffered-io.c32
1 files changed, 17 insertions, 15 deletions
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 00e0e94c953e..608cd2e5a7c9 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -769,6 +769,7 @@ static size_t iomap_write_end(struct iomap_iter *iter, loff_t pos, size_t len,
static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i)
{
loff_t length = iomap_length(iter);
+ size_t chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER;
loff_t pos = iter->pos;
ssize_t written = 0;
long status = 0;
@@ -777,15 +778,12 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i)
do {
struct folio *folio;
- struct page *page;
- unsigned long offset; /* Offset into pagecache page */
- unsigned long bytes; /* Bytes to write to page */
+ size_t offset; /* Offset into folio */
+ size_t bytes; /* Bytes to write to folio */
size_t copied; /* Bytes copied from user */
- offset = offset_in_page(pos);
- bytes = min_t(unsigned long, PAGE_SIZE - offset,
- iov_iter_count(i));
-again:
+ offset = pos & (chunk - 1);
+ bytes = min(chunk - offset, iov_iter_count(i));
status = balance_dirty_pages_ratelimited_flags(mapping,
bdp_flags);
if (unlikely(status))
@@ -815,12 +813,14 @@ again:
if (iter->iomap.flags & IOMAP_F_STALE)
break;
- page = folio_file_page(folio, pos >> PAGE_SHIFT);
- if (mapping_writably_mapped(mapping))
- flush_dcache_page(page);
+ offset = offset_in_folio(folio, pos);
+ if (bytes > folio_size(folio) - offset)
+ bytes = folio_size(folio) - offset;
- copied = copy_page_from_iter_atomic(page, offset, bytes, i);
+ if (mapping_writably_mapped(mapping))
+ flush_dcache_folio(folio);
+ copied = copy_folio_from_iter_atomic(folio, offset, bytes, i);
status = iomap_write_end(iter, pos, bytes, copied, folio);
if (unlikely(copied != status))
@@ -836,11 +836,13 @@ again:
*/
if (copied)
bytes = copied;
- goto again;
+ if (chunk > PAGE_SIZE)
+ chunk /= 2;
+ } else {
+ pos += status;
+ written += status;
+ length -= status;
}
- pos += status;
- written += status;
- length -= status;
} while (iov_iter_count(i) && length);
if (status == -EAGAIN) {