Btrfs: in scrub repair code, simplify alloc error handling

In the scrub repair code, the code is changed to handle memory
allocation errors a little bit smarter. The change is to handle
it just like a read error. This simplifies the code and removes
a couple of lines of code, since the code to handle read errors
is there anyway.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 26 insertions, 35 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 7d38f4073243..fcd5bccaa4ed 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -151,10 +151,10 @@ static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
                                      struct btrfs_mapping_tree *map_tree,
                                      u64 length, u64 logical,
                                      struct scrub_block *sblock);
-static int scrub_recheck_block(struct btrfs_fs_info *fs_info,
-                               struct scrub_block *sblock, int is_metadata,
-                               int have_csum, u8 *csum, u64 generation,
-                               u16 csum_size);
+static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
+                                struct scrub_block *sblock, int is_metadata,
+                                int have_csum, u8 *csum, u64 generation,
+                                u16 csum_size);
 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
                                          struct scrub_block *sblock,
                                          int is_metadata, int have_csum,
@@ -718,16 +718,8 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
         sblock_bad = sblocks_for_recheck + failed_mirror_index;
 
         /* build and submit the bios for the failed mirror, check checksums */
-        ret = scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
-                                  csum, generation, sctx->csum_size);
-        if (ret) {
-                spin_lock(&sctx->stat_lock);
-                sctx->stat.read_errors++;
-                sctx->stat.uncorrectable_errors++;
-                spin_unlock(&sctx->stat_lock);
-                btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
-                goto out;
-        }
+        scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
+                            csum, generation, sctx->csum_size);
 
         if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
             sblock_bad->no_io_error_seen) {
@@ -843,10 +835,11 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
                 sblock_other = sblocks_for_recheck + mirror_index;
 
                 /* build and submit the bios, check checksums */
-                ret = scrub_recheck_block(fs_info, sblock_other, is_metadata,
-                                          have_csum, csum, generation,
-                                          sctx->csum_size);
-                if (!ret && !sblock_other->header_error &&
+                scrub_recheck_block(fs_info, sblock_other, is_metadata,
+                                    have_csum, csum, generation,
+                                    sctx->csum_size);
+
+                if (!sblock_other->header_error &&
                     !sblock_other->checksum_error &&
                     sblock_other->no_io_error_seen) {
                         int force_write = is_metadata || have_csum;
@@ -931,10 +924,10 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
                          * is verified, but most likely the data comes out
                          * of the page cache.
                          */
-                        ret = scrub_recheck_block(fs_info, sblock_bad,
-                                                  is_metadata, have_csum, csum,
-                                                  generation, sctx->csum_size);
-                        if (!ret && !sblock_bad->header_error &&
+                        scrub_recheck_block(fs_info, sblock_bad,
+                                            is_metadata, have_csum, csum,
+                                            generation, sctx->csum_size);
+                        if (!sblock_bad->header_error &&
                             !sblock_bad->checksum_error &&
                             sblock_bad->no_io_error_seen)
                                 goto corrected_error;
@@ -1061,10 +1054,10 @@ leave_nomem:
  * to take those pages that are not errored from all the mirrors so that
  * the pages that are errored in the just handled mirror can be repaired.
  */
-static int scrub_recheck_block(struct btrfs_fs_info *fs_info,
-                               struct scrub_block *sblock, int is_metadata,
-                               int have_csum, u8 *csum, u64 generation,
-                               u16 csum_size)
+static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
+                                struct scrub_block *sblock, int is_metadata,
+                                int have_csum, u8 *csum, u64 generation,
+                                u16 csum_size)
 {
         int page_num;
 
@@ -1074,7 +1067,6 @@ static int scrub_recheck_block(struct btrfs_fs_info *fs_info,
 
         for (page_num = 0; page_num < sblock->page_count; page_num++) {
                 struct bio *bio;
-                int ret;
                 struct scrub_page *page = sblock->pagev[page_num];
                 DECLARE_COMPLETION_ONSTACK(complete);
 
@@ -1086,18 +1078,17 @@ static int scrub_recheck_block(struct btrfs_fs_info *fs_info,
 
                 WARN_ON(!page->page);
                 bio = bio_alloc(GFP_NOFS, 1);
-                if (!bio)
-                        return -EIO;
+                if (!bio) {
+                        page->io_error = 1;
+                        sblock->no_io_error_seen = 0;
+                        continue;
+                }
                 bio->bi_bdev = page->dev->bdev;
                 bio->bi_sector = page->physical >> 9;
                 bio->bi_end_io = scrub_complete_bio_end_io;
                 bio->bi_private = &complete;
 
-                ret = bio_add_page(bio, page->page, PAGE_SIZE, 0);
-                if (PAGE_SIZE != ret) {
-                        bio_put(bio);
-                        return -EIO;
-                }
+                bio_add_page(bio, page->page, PAGE_SIZE, 0);
                 btrfsic_submit_bio(READ, bio);
 
                 /* this will also unplug the queue */
@@ -1114,7 +1105,7 @@ static int scrub_recheck_block(struct btrfs_fs_info *fs_info,
                                              have_csum, csum, generation,
                                              csum_size);
 
-        return 0;
+        return;
 }
 
 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,