As the part of getting extra mirror in __btrfs_map_block is
self-independent, this puts it into a separate function.
Reviewed-by: Qu Wenruo <quwen...@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li....@oracle.com>
---
fs/btrfs/volumes.c | 161 +++++++++++++++++++++++++++++------------------------
1 file changed, 89 insertions(+), 72 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f94a45e..e3656e9 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -139,6 +139,11 @@ static int btrfs_relocate_sys_chunks(struct btrfs_fs_info
*fs_info);
static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
+static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
+ enum btrfs_map_op op,
+ u64 logical, u64 *length,
+ struct btrfs_bio **bbio_ret,
+ int mirror_num, int need_raid_map);
DEFINE_MUTEX(uuid_mutex);
static LIST_HEAD(fs_uuids);
@@ -5444,6 +5449,83 @@ static int __btrfs_map_block_for_discard(struct
btrfs_fs_info *fs_info,
return ret;
}
+/*
+ * In dev-replace case, for repair case (that's the only case where the mirror
+ * is selected explicitly when calling btrfs_map_block), blocks left of the
+ * left cursor can also be read from the target drive.
+ *
+ * For REQ_GET_READ_MIRRORS, the target drive is added as the last one to the
+ * array of stripes.
+ * For READ, it also needs to be supported using the same mirror number.
+ *
+ * If the requested block is not left of the left cursor, EIO is returned. This
+ * can happen because btrfs_num_copies() returns one more in the dev-replace
+ * case.
+ */
+static int get_extra_mirror_from_replace(struct btrfs_fs_info *fs_info,
+ u64 logical, u64 length,
+ u64 srcdev_devid, int *mirror_num,
+ u64 *physical)
+{
+ struct btrfs_bio *bbio = NULL;
+ int num_stripes;
+ int index_srcdev = 0;
+ int found = 0;
+ u64 physical_of_found = 0;
+ int i;
+ int ret = 0;
+
+ ret = __btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
+ logical, &length, &bbio, 0, 0);
+ if (ret) {
+ ASSERT(bbio == NULL);
+ return ret;
+ }
+
+ num_stripes = bbio->num_stripes;
+ if (*mirror_num > num_stripes) {
+ /*
+ * BTRFS_MAP_GET_READ_MIRRORS does not contain this mirror,
+ * that means that the requested area is not left of the left
+ * cursor
+ */
+ btrfs_put_bbio(bbio);
+ return -EIO;
+ }
+
+ /*
+ * process the rest of the function using the mirror_num of the source
+ * drive. Therefore look it up first. At the end, patch the device
+ * pointer to the one of the target drive.
+ */
+ for (i = 0; i < num_stripes; i++) {
+ if (bbio->stripes[i].dev->devid != srcdev_devid)
+ continue;
+
+ /*
+ * In case of DUP, in order to keep it simple, only add the
+ * mirror with the lowest physical address
+ */
+ if (found &&
+ physical_of_found <= bbio->stripes[i].physical)
+ continue;
+
+ index_srcdev = i;
+ found = 1;
+ physical_of_found = bbio->stripes[i].physical;
+ }
+
+ btrfs_put_bbio(bbio);
+
+ ASSERT(found);
+ if (!found)
+ return -EIO;
+
+ *mirror_num = index_srcdev + 1;
+ *physical = physical_of_found;
+ return ret;
+}
+
static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
enum btrfs_map_op op,
u64 logical, u64 *length,
@@ -5548,79 +5630,14 @@ static int __btrfs_map_block(struct btrfs_fs_info
*fs_info,
if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
op != BTRFS_MAP_WRITE && op != BTRFS_MAP_GET_READ_MIRRORS &&
dev_replace->tgtdev != NULL) {
- /*
- * in dev-replace case, for repair case (that's the only
- * case where the mirror is selected explicitly when
- * calling btrfs_map_block), blocks left of the left cursor
- * can also be read from the target drive.
- * For REQ_GET_READ_MIRRORS, the target drive is added as
- * the last one to the array of stripes. For READ, it also
- * needs to be supported using the same mirror number.
- * If the requested block is not left of the left cursor,
- * EIO is returned. This can happen because btrfs_num_copies()
- * returns one more in the dev-replace case.
- */
- u64 tmp_length = *length;
- struct btrfs_bio *tmp_bbio = NULL;
- int tmp_num_stripes;
- u64 srcdev_devid = dev_replace->srcdev->devid;
- int index_srcdev = 0;
- int found = 0;
- u64 physical_of_found = 0;
-
- ret = __btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
- logical, &tmp_length, &tmp_bbio, 0, 0);
- if (ret) {
- WARN_ON(tmp_bbio != NULL);
- goto out;
- }
-
- tmp_num_stripes = tmp_bbio->num_stripes;
- if (mirror_num > tmp_num_stripes) {
- /*
- * BTRFS_MAP_GET_READ_MIRRORS does not contain this
- * mirror, that means that the requested area
- * is not left of the left cursor
- */
- ret = -EIO;
- btrfs_put_bbio(tmp_bbio);
- goto out;
- }
-
- /*
- * process the rest of the function using the mirror_num
- * of the source drive. Therefore look it up first.
- * At the end, patch the device pointer to the one of the
- * target drive.
- */
- for (i = 0; i < tmp_num_stripes; i++) {
- if (tmp_bbio->stripes[i].dev->devid != srcdev_devid)
- continue;
-
- /*
- * In case of DUP, in order to keep it simple, only add
- * the mirror with the lowest physical address
- */
- if (found &&
- physical_of_found <= tmp_bbio->stripes[i].physical)
- continue;
-
- index_srcdev = i;
- found = 1;
- physical_of_found = tmp_bbio->stripes[i].physical;
- }
-
- btrfs_put_bbio(tmp_bbio);
-
- if (!found) {
- WARN_ON(1);
- ret = -EIO;
+ ret = get_extra_mirror_from_replace(fs_info, logical, *length,
+ dev_replace->srcdev->devid,
+ &mirror_num,
+ &physical_to_patch_in_first_stripe);
+ if (ret)
goto out;
- }
-
- mirror_num = index_srcdev + 1;
- patch_the_first_stripe_for_dev_replace = 1;
- physical_to_patch_in_first_stripe = physical_of_found;
+ else
+ patch_the_first_stripe_for_dev_replace = 1;
} else if (mirror_num > map->num_stripes) {
mirror_num = 0;
}
--
2.5.5
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