diff options
| -rw-r--r-- | fs/btrfs/volumes.c | 14 | ||||
| -rw-r--r-- | fs/btrfs/volumes.h | 13 |
2 files changed, 26 insertions, 1 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 07c6b0c85339..ed4163b54f75 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1217,6 +1217,7 @@ static int open_fs_devices(struct btrfs_fs_devices *fs_devices, fs_devices->latest_bdev = latest_dev->bdev; fs_devices->total_rw_bytes = 0; fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_REGULAR; + fs_devices->read_policy = BTRFS_READ_POLICY_PID; return 0; } @@ -5479,7 +5480,18 @@ static int find_live_mirror(struct btrfs_fs_info *fs_info, else num_stripes = map->num_stripes; - preferred_mirror = first + current->pid % num_stripes; + switch (fs_info->fs_devices->read_policy) { + default: + /* Shouldn't happen, just warn and use pid instead of failing */ + btrfs_warn_rl(fs_info, + "unknown read_policy type %u, reset to pid", + fs_info->fs_devices->read_policy); + fs_info->fs_devices->read_policy = BTRFS_READ_POLICY_PID; + fallthrough; + case BTRFS_READ_POLICY_PID: + preferred_mirror = first + (current->pid % num_stripes); + break; + } if (dev_replace_is_ongoing && fs_info->dev_replace.cont_reading_from_srcdev_mode == diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 232f02bd214f..34fd440fd30b 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -211,6 +211,16 @@ enum btrfs_chunk_allocation_policy { BTRFS_CHUNK_ALLOC_REGULAR, }; +/* + * Read policies for mirrored block group profiles, read picks the stripe based + * on these policies. + */ +enum btrfs_read_policy { + /* Use process PID to choose the stripe */ + BTRFS_READ_POLICY_PID, + BTRFS_NR_READ_POLICY, +}; + struct btrfs_fs_devices { u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */ u8 metadata_uuid[BTRFS_FSID_SIZE]; @@ -264,6 +274,9 @@ struct btrfs_fs_devices { struct completion kobj_unregister; enum btrfs_chunk_allocation_policy chunk_alloc_policy; + + /* Policy used to read the mirrored stripes */ + enum btrfs_read_policy read_policy; }; #define BTRFS_BIO_INLINE_CSUM_SIZE 64 |