erofs: add REQ_RAHEAD flag to readahead requests

Let's add REQ_RAHEAD flag so it'd be easier to identify
readahead I/O requests in blktrace.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200919072730.24989-3-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 459ecb4..347be14 100644 (file)
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -224,7 +224,7 @@ submit_bio_retry:
                bio_set_dev(bio, sb->s_bdev);
                bio->bi_iter.bi_sector = (sector_t)blknr <<
                        LOG_SECTORS_PER_BLOCK;
-               bio->bi_opf = REQ_OP_READ;
+               bio->bi_opf = REQ_OP_READ | (ra ? REQ_RAHEAD : 0);
        }
 
        err = bio_add_page(bio, page, PAGE_SIZE, 0);

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index bee6ce7..50912a5 100644 (file)
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -135,6 +135,7 @@ struct z_erofs_decompress_frontend {
        struct z_erofs_collector clt;
        struct erofs_map_blocks map;
 
+       bool readahead;
        /* used for applying cache strategy on the fly */
        bool backmost;
        erofs_off_t headoffset;
@@ -1148,7 +1149,7 @@ static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl,
 }
 
 static void z_erofs_submit_queue(struct super_block *sb,
-                                z_erofs_next_pcluster_t owned_head,
+                                struct z_erofs_decompress_frontend *f,
                                 struct list_head *pagepool,
                                 struct z_erofs_decompressqueue *fgq,
                                 bool *force_fg)
@@ -1157,6 +1158,7 @@ static void z_erofs_submit_queue(struct super_block *sb,
        z_erofs_next_pcluster_t qtail[NR_JOBQUEUES];
        struct z_erofs_decompressqueue *q[NR_JOBQUEUES];
        void *bi_private;
+       z_erofs_next_pcluster_t owned_head = f->clt.owned_head;
        /* since bio will be NULL, no need to initialize last_index */
        pgoff_t last_index;
        unsigned int nr_bios = 0;
@@ -1212,6 +1214,8 @@ submit_bio_retry:
                                        LOG_SECTORS_PER_BLOCK;
                                bio->bi_private = bi_private;
                                bio->bi_opf = REQ_OP_READ;
+                               if (f->readahead)
+                                       bio->bi_opf |= REQ_RAHEAD;
                                ++nr_bios;
                        }
 
@@ -1243,14 +1247,14 @@ submit_bio_retry:
 }
 
 static void z_erofs_runqueue(struct super_block *sb,
-                            struct z_erofs_collector *clt,
+                            struct z_erofs_decompress_frontend *f,
                             struct list_head *pagepool, bool force_fg)
 {
        struct z_erofs_decompressqueue io[NR_JOBQUEUES];
 
-       if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
+       if (f->clt.owned_head == Z_EROFS_PCLUSTER_TAIL)
                return;
-       z_erofs_submit_queue(sb, clt->owned_head, pagepool, io, &force_fg);
+       z_erofs_submit_queue(sb, f, pagepool, io, &force_fg);
 
        /* handle bypass queue (no i/o pclusters) immediately */
        z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool);
@@ -1281,7 +1285,7 @@ static int z_erofs_readpage(struct file *file, struct page *page)
        (void)z_erofs_collector_end(&f.clt);
 
        /* if some compressed cluster ready, need submit them anyway */
-       z_erofs_runqueue(inode->i_sb, &f.clt, &pagepool, true);
+       z_erofs_runqueue(inode->i_sb, &f, &pagepool, true);
 
        if (err)
                erofs_err(inode->i_sb, "failed to read, err [%d]", err);
@@ -1307,6 +1311,7 @@ static void z_erofs_readahead(struct readahead_control *rac)
 
        trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false);
 
+       f.readahead = true;
        f.headoffset = readahead_pos(rac);
 
        while ((page = readahead_page(rac))) {
@@ -1340,7 +1345,7 @@ static void z_erofs_readahead(struct readahead_control *rac)
 
        (void)z_erofs_collector_end(&f.clt);
 
-       z_erofs_runqueue(inode->i_sb, &f.clt, &pagepool, sync);
+       z_erofs_runqueue(inode->i_sb, &f, &pagepool, sync);
 
        if (f.map.mpage)
                put_page(f.map.mpage);