btrfs: raid56: extract the recovery bio list build code into a helper

This new helper will be also utilized in the incoming refactor of
recovery path.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 66dd4e9752a97411e24e6ad947548827ea995730..9234d3423b3174913b10d67ad03ae200059b3b6c 100644 (file)
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -2134,30 +2134,14 @@ static void raid_recover_end_io_work(struct work_struct *work)
                __raid_recover_end_io(rbio);
 }
 
-/*
- * reads everything we need off the disk to reconstruct
- * the parity. endio handlers trigger final reconstruction
- * when the IO is done.
- *
- * This is used both for reads from the higher layers and for
- * parity construction required to finish a rmw cycle.
- */
-static int __raid56_parity_recover(struct btrfs_raid_bio *rbio)
+static int recover_assemble_read_bios(struct btrfs_raid_bio *rbio,
+                                     struct bio_list *bio_list)
 {
-       int bios_to_read = 0;
-       struct bio_list bio_list;
-       int ret;
-       int total_sector_nr;
        struct bio *bio;
+       int total_sector_nr;
+       int ret = 0;
 
-       bio_list_init(&bio_list);
-
-       ret = alloc_rbio_pages(rbio);
-       if (ret)
-               goto cleanup;
-
-       atomic_set(&rbio->error, 0);
-
+       ASSERT(bio_list_size(bio_list) == 0);
        /*
         * Read everything that hasn't failed. However this time we will
         * not trust any cached sector.
@@ -2180,11 +2164,45 @@ static int __raid56_parity_recover(struct btrfs_raid_bio *rbio)
                        continue;
                }
                sector = rbio_stripe_sector(rbio, stripe, sectornr);
-               ret = rbio_add_io_sector(rbio, &bio_list, sector, stripe,
+               ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
                                         sectornr, REQ_OP_READ);
                if (ret < 0)
-                       goto cleanup;
+                       goto error;
        }
+       return 0;
+error:
+       while ((bio = bio_list_pop(bio_list)))
+               bio_put(bio);
+
+       return -EIO;
+}
+
+/*
+ * reads everything we need off the disk to reconstruct
+ * the parity. endio handlers trigger final reconstruction
+ * when the IO is done.
+ *
+ * This is used both for reads from the higher layers and for
+ * parity construction required to finish a rmw cycle.
+ */
+static int __raid56_parity_recover(struct btrfs_raid_bio *rbio)
+{
+       int bios_to_read = 0;
+       struct bio_list bio_list;
+       int ret;
+       struct bio *bio;
+
+       bio_list_init(&bio_list);
+
+       ret = alloc_rbio_pages(rbio);
+       if (ret)
+               goto cleanup;
+
+       atomic_set(&rbio->error, 0);
+
+       ret = recover_assemble_read_bios(rbio, &bio_list);
+       if (ret < 0)
+               goto cleanup;
 
        bios_to_read = bio_list_size(&bio_list);
        if (!bios_to_read) {