erofs: introduce z_erofs_do_decompressed_bvec()

Both out_bvecs and in_bvecs share the common logic for decompressed
buffers. So let's make a helper for this.

Acked-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220715154203.48093-15-hsiangkao@linux.alibaba.com

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index d93ba0adcf9ec09f0eeb424dcbc658fafcc6d1e4..d4db2c1d53a6d7f33b316f10e2d7da6c0b84c73b 100644 (file)
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -861,6 +861,26 @@ struct z_erofs_decompress_backend {
        unsigned int onstack_used;
 };
 
+static int z_erofs_do_decompressed_bvec(struct z_erofs_decompress_backend *be,
+                                       struct z_erofs_bvec *bvec)
+{
+       unsigned int pgnr = (bvec->offset + be->pcl->pageofs_out) >> PAGE_SHIFT;
+       struct page *oldpage;
+
+       DBG_BUGON(pgnr >= be->pcl->nr_pages);
+       oldpage = be->decompressed_pages[pgnr];
+       be->decompressed_pages[pgnr] = bvec->page;
+
+       /* error out if one pcluster is refenenced multiple times. */
+       if (oldpage) {
+               DBG_BUGON(1);
+               z_erofs_page_mark_eio(oldpage);
+               z_erofs_onlinepage_endio(oldpage);
+               return -EFSCORRUPTED;
+       }
+       return 0;
+}
+
 static int z_erofs_parse_out_bvecs(struct z_erofs_decompress_backend *be)
 {
        struct z_erofs_pcluster *pcl = be->pcl;
@@ -871,27 +891,14 @@ static int z_erofs_parse_out_bvecs(struct z_erofs_decompress_backend *be)
        z_erofs_bvec_iter_begin(&biter, &pcl->bvset, Z_EROFS_INLINE_BVECS, 0);
        for (i = 0; i < pcl->vcnt; ++i) {
                struct z_erofs_bvec bvec;
-               unsigned int pgnr;
 
                z_erofs_bvec_dequeue(&biter, &bvec, &old_bvpage);
 
                if (old_bvpage)
                        z_erofs_put_shortlivedpage(be->pagepool, old_bvpage);
 
-               pgnr = (bvec.offset + pcl->pageofs_out) >> PAGE_SHIFT;
-               DBG_BUGON(pgnr >= pcl->nr_pages);
                DBG_BUGON(z_erofs_page_is_invalidated(bvec.page));
-               /*
-                * currently EROFS doesn't support multiref(dedup),
-                * so here erroring out one multiref page.
-                */
-               if (be->decompressed_pages[pgnr]) {
-                       DBG_BUGON(1);
-                       z_erofs_page_mark_eio(be->decompressed_pages[pgnr]);
-                       z_erofs_onlinepage_endio(be->decompressed_pages[pgnr]);
-                       err = -EFSCORRUPTED;
-               }
-               be->decompressed_pages[pgnr] = bvec.page;
+               err = z_erofs_do_decompressed_bvec(be, &bvec);
        }
 
        old_bvpage = z_erofs_bvec_iter_end(&biter);
@@ -911,7 +918,6 @@ static int z_erofs_parse_in_bvecs(struct z_erofs_decompress_backend *be,
        for (i = 0; i < pclusterpages; ++i) {
                struct z_erofs_bvec *bvec = &pcl->compressed_bvecs[i];
                struct page *page = bvec->page;
-               unsigned int pgnr;
 
                /* compressed pages ought to be present before decompressing */
                if (!page) {
@@ -933,18 +939,7 @@ static int z_erofs_parse_in_bvecs(struct z_erofs_decompress_backend *be,
                                        err = -EIO;
                                continue;
                        }
-
-                       pgnr = (bvec->offset + pcl->pageofs_out) >> PAGE_SHIFT;
-                       DBG_BUGON(pgnr >= pcl->nr_pages);
-                       if (be->decompressed_pages[pgnr]) {
-                               DBG_BUGON(1);
-                               z_erofs_page_mark_eio(
-                                               be->decompressed_pages[pgnr]);
-                               z_erofs_onlinepage_endio(
-                                               be->decompressed_pages[pgnr]);
-                               err = -EFSCORRUPTED;
-                       }
-                       be->decompressed_pages[pgnr] = page;
+                       err = z_erofs_do_decompressed_bvec(be, bvec);
                        *overlapped = true;
                }
        }