btrfs: do reverse path readahead in btrfs_shrink_device

[sfrench/cifs-2.6.git] / fs / btrfs / volumes.c

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 4fc22a6962064b85d25ce1bbf09b6d7334938d87..78f6cd1de33aca95a555ca19961f3da39fb6f3d7 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -42,6 +42,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
                .ncopies        = 2,
                .raid_name      = "raid10",
                .bg_flag        = BTRFS_BLOCK_GROUP_RAID10,
+               .mindev_error   = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
        },
        [BTRFS_RAID_RAID1] = {
                .sub_stripes    = 1,
@@ -53,6 +54,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
                .ncopies        = 2,
                .raid_name      = "raid1",
                .bg_flag        = BTRFS_BLOCK_GROUP_RAID1,
+               .mindev_error   = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
        },
        [BTRFS_RAID_DUP] = {
                .sub_stripes    = 1,
@@ -64,6 +66,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
                .ncopies        = 2,
                .raid_name      = "dup",
                .bg_flag        = BTRFS_BLOCK_GROUP_DUP,
+               .mindev_error   = 0,
        },
        [BTRFS_RAID_RAID0] = {
                .sub_stripes    = 1,
@@ -75,6 +78,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
                .ncopies        = 1,
                .raid_name      = "raid0",
                .bg_flag        = BTRFS_BLOCK_GROUP_RAID0,
+               .mindev_error   = 0,
        },
        [BTRFS_RAID_SINGLE] = {
                .sub_stripes    = 1,
@@ -86,6 +90,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
                .ncopies        = 1,
                .raid_name      = "single",
                .bg_flag        = 0,
+               .mindev_error   = 0,
        },
        [BTRFS_RAID_RAID5] = {
                .sub_stripes    = 1,
@@ -97,6 +102,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
                .ncopies        = 2,
                .raid_name      = "raid5",
                .bg_flag        = BTRFS_BLOCK_GROUP_RAID5,
+               .mindev_error   = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
        },
        [BTRFS_RAID_RAID6] = {
                .sub_stripes    = 1,
@@ -108,6 +114,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
                .ncopies        = 3,
                .raid_name      = "raid6",
                .bg_flag        = BTRFS_BLOCK_GROUP_RAID6,
+               .mindev_error   = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
        },
 };
 
@@ -119,21 +126,6 @@ const char *get_raid_name(enum btrfs_raid_types type)
        return btrfs_raid_array[type].raid_name;
 }
 
-/*
- * Table to convert BTRFS_RAID_* to the error code if minimum number of devices
- * condition is not met. Zero means there's no corresponding
- * BTRFS_ERROR_DEV_*_NOT_MET value.
- */
-const int btrfs_raid_mindev_error[BTRFS_NR_RAID_TYPES] = {
-       [BTRFS_RAID_RAID10] = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
-       [BTRFS_RAID_RAID1]  = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
-       [BTRFS_RAID_DUP]    = 0,
-       [BTRFS_RAID_RAID0]  = 0,
-       [BTRFS_RAID_SINGLE] = 0,
-       [BTRFS_RAID_RAID5]  = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
-       [BTRFS_RAID_RAID6]  = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
-};
-
 static int init_first_rw_device(struct btrfs_trans_handle *trans,
                                struct btrfs_fs_info *fs_info);
 static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info);
@@ -1900,7 +1892,7 @@ static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
                        continue;
 
                if (num_devices < btrfs_raid_array[i].devs_min) {
-                       int ret = btrfs_raid_mindev_error[i];
+                       int ret = btrfs_raid_array[i].mindev_error;
 
                        if (ret)
                                return ret;
@@ -4422,7 +4414,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
        if (!path)
                return -ENOMEM;
 
-       path->reada = READA_FORWARD;
+       path->reada = READA_BACK;
 
        mutex_lock(&fs_info->chunk_mutex);