mm/swap: get the swap device offset directly

folio_file_pos and page_file_offset are for mixed usage of swap cache and
page cache, it can't be page cache here, so introduce a new helper to get
the swap offset in swap device directly.

Need to include swapops.h in mm/swap.h to ensure swp_offset is always
defined before use.

Link: https://lkml.kernel.org/r/20240521175854.96038-9-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Marc Dionne <marc.dionne@auristor.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/page_io.c b/mm/page_io.c
index 0a150c240bf4fd919b65ab38b4626edf1efd5fe8..41e8d738c6d28549568afe251a15bbc113ab5007 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -280,7 +280,7 @@ static void sio_write_complete(struct kiocb *iocb, long ret)
                 * be temporary.
                 */
                pr_err_ratelimited("Write error %ld on dio swapfile (%llu)\n",
-                                  ret, page_file_offset(page));
+                                  ret, swap_dev_pos(page_swap_entry(page)));
                for (p = 0; p < sio->pages; p++) {
                        page = sio->bvec[p].bv_page;
                        set_page_dirty(page);
@@ -299,7 +299,7 @@ static void swap_writepage_fs(struct folio *folio, struct writeback_control *wbc
        struct swap_iocb *sio = NULL;
        struct swap_info_struct *sis = swp_swap_info(folio->swap);
        struct file *swap_file = sis->swap_file;
-       loff_t pos = folio_file_pos(folio);
+       loff_t pos = swap_dev_pos(folio->swap);
 
        count_swpout_vm_event(folio);
        folio_start_writeback(folio);
@@ -430,7 +430,7 @@ static void swap_read_folio_fs(struct folio *folio, struct swap_iocb **plug)
 {
        struct swap_info_struct *sis = swp_swap_info(folio->swap);
        struct swap_iocb *sio = NULL;
-       loff_t pos = folio_file_pos(folio);
+       loff_t pos = swap_dev_pos(folio->swap);
 
        if (plug)
                sio = *plug;

diff --git a/mm/swap.h b/mm/swap.h
index fc2f6ade7f80b399707bcc67c44f813aea0b846d..82023ab93205f4a676ac0a41ee2a8c16bc239ab5 100644 (file)
--- a/mm/swap.h
+++ b/mm/swap.h
@@ -5,6 +5,7 @@
 struct mempolicy;
 
 #ifdef CONFIG_SWAP
+#include <linux/swapops.h> /* for swp_offset */
 #include <linux/blk_types.h> /* for bio_end_io_t */
 
 /* linux/mm/page_io.c */
@@ -31,6 +32,14 @@ extern struct address_space *swapper_spaces[];
        (&swapper_spaces[swp_type(entry)][swp_offset(entry) \
                >> SWAP_ADDRESS_SPACE_SHIFT])
 
+/*
+ * Return the swap device position of the swap entry.
+ */
+static inline loff_t swap_dev_pos(swp_entry_t entry)
+{
+       return ((loff_t)swp_offset(entry)) << PAGE_SHIFT;
+}
+
 void show_swap_cache_info(void);
 bool add_to_swap(struct folio *folio);
 void *get_shadow_from_swap_cache(swp_entry_t entry);