btrfs: count super block write errors in device instead of tracking folio error state
Currently the error status of super block write is tracked in page/folio
status bit Error. For that we need to keep the reference for the whole
duration of write and wait.
Count the number of superblock writeback errors in the btrfs_device.
That means we don't need the folio to stay around until it's waited for,
and can avoid the extra call to folio_get/put.
Also remove a mention of PageError in a comment as it's the last mention
of the page Error state.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 90c5446..a91a805 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3634,11 +3634,15 @@ static void btrfs_end_super_write(struct bio *bio)
"lost super block write due to IO error on %s (%d)",
btrfs_dev_name(device),
blk_status_to_errno(bio->bi_status));
- folio_set_error(fi.folio);
btrfs_dev_stat_inc_and_print(device,
BTRFS_DEV_STAT_WRITE_ERRS);
+ /* Ensure failure if the primary sb fails. */
+ if (bio->bi_opf & REQ_FUA)
+ atomic_add(BTRFS_SUPER_PRIMARY_WRITE_ERROR,
+ &device->sb_write_errors);
+ else
+ atomic_inc(&device->sb_write_errors);
}
-
folio_unlock(fi.folio);
folio_put(fi.folio);
}
@@ -3742,10 +3746,11 @@ static int write_dev_supers(struct btrfs_device *device,
struct address_space *mapping = device->bdev->bd_inode->i_mapping;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
int i;
- int errors = 0;
int ret;
u64 bytenr, bytenr_orig;
+ atomic_set(&device->sb_write_errors, 0);
+
if (max_mirrors == 0)
max_mirrors = BTRFS_SUPER_MIRROR_MAX;
@@ -3765,7 +3770,7 @@ static int write_dev_supers(struct btrfs_device *device,
btrfs_err(device->fs_info,
"couldn't get super block location for mirror %d",
i);
- errors++;
+ atomic_inc(&device->sb_write_errors);
continue;
}
if (bytenr + BTRFS_SUPER_INFO_SIZE >=
@@ -3785,14 +3790,11 @@ static int write_dev_supers(struct btrfs_device *device,
btrfs_err(device->fs_info,
"couldn't get super block page for bytenr %llu",
bytenr);
- errors++;
+ atomic_inc(&device->sb_write_errors);
continue;
}
ASSERT(folio_order(folio) == 0);
- /* Bump the refcount for wait_dev_supers() */
- folio_get(folio);
-
offset = offset_in_folio(folio, bytenr);
disk_super = folio_address(folio) + offset;
memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);
@@ -3820,16 +3822,17 @@ static int write_dev_supers(struct btrfs_device *device,
submit_bio(bio);
if (btrfs_advance_sb_log(device, i))
- errors++;
+ atomic_inc(&device->sb_write_errors);
}
- return errors < i ? 0 : -1;
+ return atomic_read(&device->sb_write_errors) < i ? 0 : -1;
}
/*
* Wait for write completion of superblocks done by write_dev_supers,
* @max_mirrors same for write and wait phases.
*
- * Return number of errors when folio is not found or not marked up to date.
+ * Return -1 if primary super block write failed or when there were no super block
+ * copies written. Otherwise 0.
*/
static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
{
@@ -3860,30 +3863,19 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
folio = filemap_get_folio(device->bdev->bd_inode->i_mapping,
bytenr >> PAGE_SHIFT);
- if (IS_ERR(folio)) {
- errors++;
- if (i == 0)
- primary_failed = true;
+ /* If the folio has been removed, then we know it completed. */
+ if (IS_ERR(folio))
continue;
- }
ASSERT(folio_order(folio) == 0);
/* Folio will be unlocked once the write completes. */
folio_wait_locked(folio);
- if (folio_test_error(folio)) {
- errors++;
- if (i == 0)
- primary_failed = true;
- }
-
- /* Drop our reference */
- folio_put(folio);
-
- /* Drop the reference from the writing run */
folio_put(folio);
}
- /* log error, force error return */
+ errors += atomic_read(&device->sb_write_errors);
+ if (errors >= BTRFS_SUPER_PRIMARY_WRITE_ERROR)
+ primary_failed = true;
if (primary_failed) {
btrfs_err(device->fs_info, "error writing primary super block to device %llu",
device->devid);
