When fewer pages are read, nr_pages may be smaller than nr_cpages. Due
to the nr_vecs limit, the compressed pages will be split into multiple
bios and then merged at the block level. In this case, nr_cpages should
be used to pre-allocate bvecs.
To handle this case, align max_nr_pages to cluster_size, which should be
enough for all compressed pages.

Signed-off-by: Jianan Huang <huangjia...@xiaomi.com>
Signed-off-by: Sheng Yong <shengyo...@xiaomi.com>
---
Changes since v2:
- Initialize index only for compressed files.
Changes since v1:
- Use aligned nr_pages instead of nr_cpages to pre-allocate bvecs.

 fs/f2fs/data.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 31e892842625..d071d9f6a811 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2303,7 +2303,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct 
bio **bio_ret,
                }
 
                if (!bio) {
-                       bio = f2fs_grab_read_bio(inode, blkaddr, nr_pages,
+                       bio = f2fs_grab_read_bio(inode, blkaddr, nr_pages - i,
                                        f2fs_ra_op_flags(rac),
                                        folio->index, for_write);
                        if (IS_ERR(bio)) {
@@ -2376,6 +2376,14 @@ static int f2fs_mpage_readpages(struct inode *inode,
        unsigned max_nr_pages = nr_pages;
        int ret = 0;
 
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+       if (f2fs_compressed_file(inode)) {
+               index = rac ? readahead_index(rac) : folio->index;
+               max_nr_pages = round_up(index + nr_pages, cc.cluster_size) -
+                               round_down(index, cc.cluster_size);
+       }
+#endif
+
        map.m_pblk = 0;
        map.m_lblk = 0;
        map.m_len = 0;
@@ -2385,7 +2393,7 @@ static int f2fs_mpage_readpages(struct inode *inode,
        map.m_seg_type = NO_CHECK_TYPE;
        map.m_may_create = false;
 
-       for (; nr_pages; nr_pages--) {
+       for (; nr_pages; nr_pages--, max_nr_pages--) {
                if (rac) {
                        folio = readahead_folio(rac);
                        prefetchw(&folio->flags);
-- 
2.43.0



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Reply via email to