1 files changed, 122 insertions, 138 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 72a838c97534..51070c0d4141 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -370,6 +370,8 @@ static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid,
 {
 	struct btrfs_fs_devices *fs_devs;
 
+	ASSERT(fsid || !metadata_fsid);
+
 	fs_devs = kzalloc(sizeof(*fs_devs), GFP_KERNEL);
 	if (!fs_devs)
 		return ERR_PTR(-ENOMEM);
@@ -380,18 +382,17 @@ static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid,
 	INIT_LIST_HEAD(&fs_devs->alloc_list);
 	INIT_LIST_HEAD(&fs_devs->fs_list);
 	INIT_LIST_HEAD(&fs_devs->seed_list);
-	if (fsid)
-		memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
 
-	if (metadata_fsid)
-		memcpy(fs_devs->metadata_uuid, metadata_fsid, BTRFS_FSID_SIZE);
-	else if (fsid)
-		memcpy(fs_devs->metadata_uuid, fsid, BTRFS_FSID_SIZE);
+	if (fsid) {
+		memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
+		memcpy(fs_devs->metadata_uuid,
+		       metadata_fsid ?: fsid, BTRFS_FSID_SIZE);
+	}
 
 	return fs_devs;
 }
 
-void btrfs_free_device(struct btrfs_device *device)
+static void btrfs_free_device(struct btrfs_device *device)
 {
 	WARN_ON(!list_empty(&device->post_commit_list));
 	rcu_string_free(device->name);
@@ -426,6 +427,21 @@ void __exit btrfs_cleanup_fs_uuids(void)
 	}
 }
 
+static bool match_fsid_fs_devices(const struct btrfs_fs_devices *fs_devices,
+				  const u8 *fsid, const u8 *metadata_fsid)
+{
+	if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) != 0)
+		return false;
+
+	if (!metadata_fsid)
+		return true;
+
+	if (memcmp(metadata_fsid, fs_devices->metadata_uuid, BTRFS_FSID_SIZE) != 0)
+		return false;
+
+	return true;
+}
+
 static noinline struct btrfs_fs_devices *find_fsid(
 		const u8 *fsid, const u8 *metadata_fsid)
 {
@@ -435,19 +451,25 @@ static noinline struct btrfs_fs_devices *find_fsid(
 
 	/* Handle non-split brain cases */
 	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
-		if (metadata_fsid) {
-			if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0
-			    && memcmp(metadata_fsid, fs_devices->metadata_uuid,
-				      BTRFS_FSID_SIZE) == 0)
-				return fs_devices;
-		} else {
-			if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
-				return fs_devices;
-		}
+		if (match_fsid_fs_devices(fs_devices, fsid, metadata_fsid))
+			return fs_devices;
 	}
 	return NULL;
 }
 
+/*
+ * First check if the metadata_uuid is different from the fsid in the given
+ * fs_devices. Then check if the given fsid is the same as the metadata_uuid
+ * in the fs_devices. If it is, return true; otherwise, return false.
+ */
+static inline bool check_fsid_changed(const struct btrfs_fs_devices *fs_devices,
+				      const u8 *fsid)
+{
+	return memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
+		      BTRFS_FSID_SIZE) != 0 &&
+	       memcmp(fs_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE) == 0;
+}
+
 static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(
 				struct btrfs_super_block *disk_super)
 {
@@ -461,14 +483,14 @@ static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(
 	 * at all and the CHANGING_FSID_V2 flag set.
 	 */
 	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
-		if (fs_devices->fsid_change &&
-		    memcmp(disk_super->metadata_uuid, fs_devices->fsid,
-			   BTRFS_FSID_SIZE) == 0 &&
-		    memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
-			   BTRFS_FSID_SIZE) == 0) {
+		if (!fs_devices->fsid_change)
+			continue;
+
+		if (match_fsid_fs_devices(fs_devices, disk_super->metadata_uuid,
+					  fs_devices->fsid))
 			return fs_devices;
-		}
 	}
+
 	/*
 	 * Handle scanned device having completed its fsid change but
 	 * belonging to a fs_devices that was created by a device that
@@ -476,13 +498,11 @@ static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(
 	 * CHANGING_FSID_V2 flag set.
 	 */
 	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
-		if (fs_devices->fsid_change &&
-		    memcmp(fs_devices->metadata_uuid,
-			   fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&
-		    memcmp(disk_super->metadata_uuid, fs_devices->metadata_uuid,
-			   BTRFS_FSID_SIZE) == 0) {
+		if (!fs_devices->fsid_change)
+			continue;
+
+		if (check_fsid_changed(fs_devices, disk_super->metadata_uuid))
 			return fs_devices;
-		}
 	}
 
 	return find_fsid(disk_super->fsid, disk_super->metadata_uuid);
@@ -490,13 +510,13 @@ static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(
 
 
 static int
-btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
+btrfs_get_bdev_and_sb(const char *device_path, blk_mode_t flags, void *holder,
 		      int flush, struct block_device **bdev,
 		      struct btrfs_super_block **disk_super)
 {
 	int ret;
 
-	*bdev = blkdev_get_by_path(device_path, flags, holder);
+	*bdev = blkdev_get_by_path(device_path, flags, holder, NULL);
 
 	if (IS_ERR(*bdev)) {
 		ret = PTR_ERR(*bdev);
@@ -507,14 +527,14 @@ btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
 		sync_blockdev(*bdev);
 	ret = set_blocksize(*bdev, BTRFS_BDEV_BLOCKSIZE);
 	if (ret) {
-		blkdev_put(*bdev, flags);
+		blkdev_put(*bdev, holder);
 		goto error;
 	}
 	invalidate_bdev(*bdev);
 	*disk_super = btrfs_read_dev_super(*bdev);
 	if (IS_ERR(*disk_super)) {
 		ret = PTR_ERR(*disk_super);
-		blkdev_put(*bdev, flags);
+		blkdev_put(*bdev, holder);
 		goto error;
 	}
 
@@ -590,7 +610,7 @@ static int btrfs_free_stale_devices(dev_t devt, struct btrfs_device *skip_device
  * fs_devices->device_list_mutex here.
  */
 static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
-			struct btrfs_device *device, fmode_t flags,
+			struct btrfs_device *device, blk_mode_t flags,
 			void *holder)
 {
 	struct block_device *bdev;
@@ -642,7 +662,7 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
 
 	device->bdev = bdev;
 	clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
-	device->mode = flags;
+	device->holder = holder;
 
 	fs_devices->open_devices++;
 	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
@@ -656,11 +676,19 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
 
 error_free_page:
 	btrfs_release_disk_super(disk_super);
-	blkdev_put(bdev, flags);
+	blkdev_put(bdev, holder);
 
 	return -EINVAL;
 }
 
+u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb)
+{
+	bool has_metadata_uuid = (btrfs_super_incompat_flags(sb) &
+				  BTRFS_FEATURE_INCOMPAT_METADATA_UUID);
+
+	return has_metadata_uuid ? sb->metadata_uuid : sb->fsid;
+}
+
 /*
  * Handle scanned device having its CHANGING_FSID_V2 flag set and the fs_devices
  * being created with a disk that has already completed its fsid change. Such
@@ -673,18 +701,16 @@ static struct btrfs_fs_devices *find_fsid_inprogress(
 	struct btrfs_fs_devices *fs_devices;
 
 	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
-		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
-			   BTRFS_FSID_SIZE) != 0 &&
-		    memcmp(fs_devices->metadata_uuid, disk_super->fsid,
-			   BTRFS_FSID_SIZE) == 0 && !fs_devices->fsid_change) {
+		if (fs_devices->fsid_change)
+			continue;
+
+		if (check_fsid_changed(fs_devices,  disk_super->fsid))
 			return fs_devices;
-		}
 	}
 
 	return find_fsid(disk_super->fsid, NULL);
 }
 
-
 static struct btrfs_fs_devices *find_fsid_changed(
 					struct btrfs_super_block *disk_super)
 {
@@ -701,10 +727,7 @@ static struct btrfs_fs_devices *find_fsid_changed(
 	 */
 	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
 		/* Changed UUIDs */
-		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
-			   BTRFS_FSID_SIZE) != 0 &&
-		    memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid,
-			   BTRFS_FSID_SIZE) == 0 &&
+		if (check_fsid_changed(fs_devices, disk_super->metadata_uuid) &&
 		    memcmp(fs_devices->fsid, disk_super->fsid,
 			   BTRFS_FSID_SIZE) != 0)
 			return fs_devices;
@@ -735,11 +758,10 @@ static struct btrfs_fs_devices *find_fsid_reverted_metadata(
 	 * fs_devices equal to the FSID of the disk.
 	 */
 	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
-		if (memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
-			   BTRFS_FSID_SIZE) != 0 &&
-		    memcmp(fs_devices->metadata_uuid, disk_super->fsid,
-			   BTRFS_FSID_SIZE) == 0 &&
-		    fs_devices->fsid_change)
+		if (!fs_devices->fsid_change)
+			continue;
+
+		if (check_fsid_changed(fs_devices, disk_super->fsid))
 			return fs_devices;
 	}
 
@@ -790,12 +812,8 @@ static noinline struct btrfs_device *device_list_add(const char *path,
 
 
 	if (!fs_devices) {
-		if (has_metadata_uuid)
-			fs_devices = alloc_fs_devices(disk_super->fsid,
-						      disk_super->metadata_uuid);
-		else
-			fs_devices = alloc_fs_devices(disk_super->fsid, NULL);
-
+		fs_devices = alloc_fs_devices(disk_super->fsid,
+				has_metadata_uuid ? disk_super->metadata_uuid : NULL);
 		if (IS_ERR(fs_devices))
 			return ERR_CAST(fs_devices);
 
@@ -1057,7 +1075,7 @@ static void __btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices,
 			continue;
 
 		if (device->bdev) {
-			blkdev_put(device->bdev, device->mode);
+			blkdev_put(device->bdev, device->holder);
 			device->bdev = NULL;
 			fs_devices->open_devices--;
 		}
@@ -1103,7 +1121,7 @@ static void btrfs_close_bdev(struct btrfs_device *device)
 		invalidate_bdev(device->bdev);
 	}
 
-	blkdev_put(device->bdev, device->mode);
+	blkdev_put(device->bdev, device->holder);
 }
 
 static void btrfs_close_one_device(struct btrfs_device *device)
@@ -1207,14 +1225,12 @@ void btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 }
 
 static int open_fs_devices(struct btrfs_fs_devices *fs_devices,
-				fmode_t flags, void *holder)
+				blk_mode_t flags, void *holder)
 {
 	struct btrfs_device *device;
 	struct btrfs_device *latest_dev = NULL;
 	struct btrfs_device *tmp_device;
 
-	flags |= FMODE_EXCL;
-
 	list_for_each_entry_safe(device, tmp_device, &fs_devices->devices,
 				 dev_list) {
 		int ret;
@@ -1257,7 +1273,7 @@ static int devid_cmp(void *priv, const struct list_head *a,
 }
 
 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
-		       fmode_t flags, void *holder)
+		       blk_mode_t flags, void *holder)
 {
 	int ret;
 
@@ -1348,8 +1364,7 @@ int btrfs_forget_devices(dev_t devt)
  * and we are not allowed to call set_blocksize during the scan. The superblock
  * is read via pagecache
  */
-struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
-					   void *holder)
+struct btrfs_device *btrfs_scan_one_device(const char *path, blk_mode_t flags)
 {
 	struct btrfs_super_block *disk_super;
 	bool new_device_added = false;
@@ -1368,16 +1383,16 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
 	 */
 
 	/*
-	 * Avoid using flag |= FMODE_EXCL here, as the systemd-udev may
-	 * initiate the device scan which may race with the user's mount
-	 * or mkfs command, resulting in failure.
-	 * Since the device scan is solely for reading purposes, there is
-	 * no need for FMODE_EXCL. Additionally, the devices are read again
+	 * Avoid an exclusive open here, as the systemd-udev may initiate the
+	 * device scan which may race with the user's mount or mkfs command,
+	 * resulting in failure.
+	 * Since the device scan is solely for reading purposes, there is no
+	 * need for an exclusive open. Additionally, the devices are read again
 	 * during the mount process. It is ok to get some inconsistent
 	 * values temporarily, as the device paths of the fsid are the only
 	 * required information for assembling the volume.
 	 */
-	bdev = blkdev_get_by_path(path, flags, holder);
+	bdev = blkdev_get_by_path(path, flags, NULL, NULL);
 	if (IS_ERR(bdev))
 		return ERR_CAST(bdev);
 
@@ -1401,7 +1416,7 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
 	btrfs_release_disk_super(disk_super);
 
 error_bdev_put:
-	blkdev_put(bdev, flags);
+	blkdev_put(bdev, NULL);
 
 	return device;
 }
@@ -1918,7 +1933,7 @@ static void update_dev_time(const char *device_path)
 		return;
 
 	now = current_time(d_inode(path.dentry));
-	inode_update_time(d_inode(path.dentry), &now, S_MTIME | S_CTIME);
+	inode_update_time(d_inode(path.dentry), &now, S_MTIME | S_CTIME | S_VERSION);
 	path_put(&path);
 }
 
@@ -2088,7 +2103,7 @@ void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
 
 int btrfs_rm_device(struct btrfs_fs_info *fs_info,
 		    struct btrfs_dev_lookup_args *args,
-		    struct block_device **bdev, fmode_t *mode)
+		    struct block_device **bdev, void **holder)
 {
 	struct btrfs_trans_handle *trans;
 	struct btrfs_device *device;
@@ -2227,7 +2242,7 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info,
 	}
 
 	*bdev = device->bdev;
-	*mode = device->mode;
+	*holder = device->holder;
 	synchronize_rcu();
 	btrfs_free_device(device);
 
@@ -2381,7 +2396,7 @@ int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
 		return -ENOMEM;
 	}
 
-	ret = btrfs_get_bdev_and_sb(path, FMODE_READ, fs_info->bdev_holder, 0,
+	ret = btrfs_get_bdev_and_sb(path, BLK_OPEN_READ, NULL, 0,
 				    &bdev, &disk_super);
 	if (ret) {
 		btrfs_put_dev_args_from_path(args);
@@ -2395,7 +2410,7 @@ int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
 	else
 		memcpy(args->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
 	btrfs_release_disk_super(disk_super);
-	blkdev_put(bdev, FMODE_READ);
+	blkdev_put(bdev, NULL);
 	return 0;
 }
 
@@ -2628,8 +2643,8 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 	if (sb_rdonly(sb) && !fs_devices->seeding)
 		return -EROFS;
 
-	bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
-				  fs_info->bdev_holder);
+	bdev = blkdev_get_by_path(device_path, BLK_OPEN_WRITE,
+				  fs_info->bdev_holder, NULL);
 	if (IS_ERR(bdev))
 		return PTR_ERR(bdev);
 
@@ -2691,7 +2706,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 	device->commit_total_bytes = device->total_bytes;
 	set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
 	clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
-	device->mode = FMODE_EXCL;
+	device->holder = fs_info->bdev_holder;
 	device->dev_stats_valid = 1;
 	set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
 
@@ -2849,7 +2864,7 @@ error_free_zone:
 error_free_device:
 	btrfs_free_device(device);
 error:
-	blkdev_put(bdev, FMODE_EXCL);
+	blkdev_put(bdev, fs_info->bdev_holder);
 	if (locked) {
 		mutex_unlock(&uuid_mutex);
 		up_write(&sb->s_umount);
@@ -4071,14 +4086,6 @@ static int alloc_profile_is_valid(u64 flags, int extended)
 	return has_single_bit_set(flags);
 }
 
-static inline int balance_need_close(struct btrfs_fs_info *fs_info)
-{
-	/* cancel requested || normal exit path */
-	return atomic_read(&fs_info->balance_cancel_req) ||
-		(atomic_read(&fs_info->balance_pause_req) == 0 &&
-		 atomic_read(&fs_info->balance_cancel_req) == 0);
-}
-
 /*
  * Validate target profile against allowed profiles and return true if it's OK.
  * Otherwise print the error message and return false.
@@ -4268,6 +4275,7 @@ int btrfs_balance(struct btrfs_fs_info *fs_info,
 	u64 num_devices;
 	unsigned seq;
 	bool reducing_redundancy;
+	bool paused = false;
 	int i;
 
 	if (btrfs_fs_closing(fs_info) ||
@@ -4398,6 +4406,7 @@ int btrfs_balance(struct btrfs_fs_info *fs_info,
 	if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req)) {
 		btrfs_info(fs_info, "balance: paused");
 		btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED);
+		paused = true;
 	}
 	/*
 	 * Balance can be canceled by:
@@ -4426,8 +4435,8 @@ int btrfs_balance(struct btrfs_fs_info *fs_info,
 		btrfs_update_ioctl_balance_args(fs_info, bargs);
 	}
 
-	if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
-	    balance_need_close(fs_info)) {
+	/* We didn't pause, we can clean everything up. */
+	if (!paused) {
 		reset_balance_state(fs_info);
 		btrfs_exclop_finish(fs_info);
 	}
@@ -4637,8 +4646,7 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
 		}
 	}
 
-	BUG_ON(fs_info->balance_ctl ||
-		test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
+	ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
 	atomic_dec(&fs_info->balance_cancel_req);
 	mutex_unlock(&fs_info->balance_mutex);
 	return 0;
@@ -6163,17 +6171,10 @@ static void handle_ops_on_dev_replace(enum btrfs_map_op op,
 	bioc->replace_nr_stripes = nr_extra_stripes;
 }
 
-static bool need_full_stripe(enum btrfs_map_op op)
-{
-	return (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS);
-}
-
 static u64 btrfs_max_io_len(struct map_lookup *map, enum btrfs_map_op op,
 			    u64 offset, u32 *stripe_nr, u64 *stripe_offset,
 			    u64 *full_stripe_start)
 {
-	ASSERT(op != BTRFS_MAP_DISCARD);
-
 	/*
 	 * Stripe_nr is the stripe where this block falls.  stripe_offset is
 	 * the offset of this block in its stripe.
@@ -6226,11 +6227,11 @@ static void set_io_stripe(struct btrfs_io_stripe *dst, const struct map_lookup *
 			stripe_offset + btrfs_stripe_nr_to_offset(stripe_nr);
 }
 
-int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
-		      u64 logical, u64 *length,
-		      struct btrfs_io_context **bioc_ret,
-		      struct btrfs_io_stripe *smap, int *mirror_num_ret,
-		      int need_raid_map)
+int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
+		    u64 logical, u64 *length,
+		    struct btrfs_io_context **bioc_ret,
+		    struct btrfs_io_stripe *smap, int *mirror_num_ret,
+		    int need_raid_map)
 {
 	struct extent_map *em;
 	struct map_lookup *map;
@@ -6253,7 +6254,6 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 	u64 max_len;
 
 	ASSERT(bioc_ret);
-	ASSERT(op != BTRFS_MAP_DISCARD);
 
 	num_copies = btrfs_num_copies(fs_info, logical, fs_info->sectorsize);
 	if (mirror_num > num_copies)
@@ -6285,21 +6285,21 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 	if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
 		stripe_index = stripe_nr % map->num_stripes;
 		stripe_nr /= map->num_stripes;
-		if (!need_full_stripe(op))
+		if (op == BTRFS_MAP_READ)
 			mirror_num = 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
-		if (need_full_stripe(op))
+		if (op != BTRFS_MAP_READ) {
 			num_stripes = map->num_stripes;
-		else if (mirror_num)
+		} else if (mirror_num) {
 			stripe_index = mirror_num - 1;
-		else {
+		} else {
 			stripe_index = find_live_mirror(fs_info, map, 0,
 					    dev_replace_is_ongoing);
 			mirror_num = stripe_index + 1;
 		}
 
 	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
-		if (need_full_stripe(op)) {
+		if (op != BTRFS_MAP_READ) {
 			num_stripes = map->num_stripes;
 		} else if (mirror_num) {
 			stripe_index = mirror_num - 1;
@@ -6313,7 +6313,7 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 		stripe_index = (stripe_nr % factor) * map->sub_stripes;
 		stripe_nr /= factor;
 
-		if (need_full_stripe(op))
+		if (op != BTRFS_MAP_READ)
 			num_stripes = map->sub_stripes;
 		else if (mirror_num)
 			stripe_index += mirror_num - 1;
@@ -6326,7 +6326,7 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 		}
 
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-		if (need_raid_map && (need_full_stripe(op) || mirror_num > 1)) {
+		if (need_raid_map && (op != BTRFS_MAP_READ || mirror_num > 1)) {
 			/*
 			 * Push stripe_nr back to the start of the full stripe
 			 * For those cases needing a full stripe, @stripe_nr
@@ -6362,7 +6362,7 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 
 			/* We distribute the parity blocks across stripes */
 			stripe_index = (stripe_nr + stripe_index) % map->num_stripes;
-			if (!need_full_stripe(op) && mirror_num <= 1)
+			if (op == BTRFS_MAP_READ && mirror_num <= 1)
 				mirror_num = 1;
 		}
 	} else {
@@ -6402,10 +6402,11 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 	 */
 	if (smap && num_alloc_stripes == 1 &&
 	    !((map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) && mirror_num > 1) &&
-	    (!need_full_stripe(op) || !dev_replace_is_ongoing ||
+	    (op == BTRFS_MAP_READ || !dev_replace_is_ongoing ||
 	     !dev_replace->tgtdev)) {
 		set_io_stripe(smap, map, stripe_index, stripe_offset, stripe_nr);
-		*mirror_num_ret = mirror_num;
+		if (mirror_num_ret)
+			*mirror_num_ret = mirror_num;
 		*bioc_ret = NULL;
 		ret = 0;
 		goto out;
@@ -6426,7 +6427,7 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 	 * It's still mostly the same as other profiles, just with extra rotation.
 	 */
 	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK && need_raid_map &&
-	    (need_full_stripe(op) || mirror_num > 1)) {
+	    (op != BTRFS_MAP_READ || mirror_num > 1)) {
 		/*
 		 * For RAID56 @stripe_nr is already the number of full stripes
 		 * before us, which is also the rotation value (needs to modulo
@@ -6453,11 +6454,11 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 		}
 	}
 
-	if (need_full_stripe(op))
+	if (op != BTRFS_MAP_READ)
 		max_errors = btrfs_chunk_max_errors(map);
 
 	if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&
-	    need_full_stripe(op)) {
+	    op != BTRFS_MAP_READ) {
 		handle_ops_on_dev_replace(op, bioc, dev_replace, logical,
 					  &num_stripes, &max_errors);
 	}
@@ -6477,23 +6478,6 @@ out:
 	return ret;
 }
 
-int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
-		      u64 logical, u64 *length,
-		      struct btrfs_io_context **bioc_ret, int mirror_num)
-{
-	return __btrfs_map_block(fs_info, op, logical, length, bioc_ret,
-				 NULL, &mirror_num, 0);
-}
-
-/* For Scrub/replace */
-int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
-		     u64 logical, u64 *length,
-		     struct btrfs_io_context **bioc_ret)
-{
-	return __btrfs_map_block(fs_info, op, logical, length, bioc_ret,
-				 NULL, NULL, 1);
-}
-
 static bool dev_args_match_fs_devices(const struct btrfs_dev_lookup_args *args,
 				      const struct btrfs_fs_devices *fs_devices)
 {
@@ -6913,7 +6897,7 @@ static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info,
 	if (IS_ERR(fs_devices))
 		return fs_devices;
 
-	ret = open_fs_devices(fs_devices, FMODE_READ, fs_info->bdev_holder);
+	ret = open_fs_devices(fs_devices, BLK_OPEN_READ, fs_info->bdev_holder);
 	if (ret) {
 		free_fs_devices(fs_devices);
 		return ERR_PTR(ret);
@@ -8070,8 +8054,8 @@ int btrfs_map_repair_block(struct btrfs_fs_info *fs_info,
 
 	ASSERT(mirror_num > 0);
 
-	ret = __btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical, &map_length,
-				&bioc, smap, &mirror_ret, true);
+	ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical, &map_length,
+			      &bioc, smap, &mirror_ret, true);
 	if (ret < 0)
 		return ret;