fs/btrfs/volumes.c

File Facts

System

Linux kernel

Corpus path

fs/btrfs/volumes.c

Extension

.c

Size

252468 bytes

Lines

8977

Domain

Core OS

Bucket

VFS And Filesystem Core

Inferred role

Core OS: implementation source

Status

source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/sched.h
• linux/sched/mm.h
• linux/slab.h
• linux/ratelimit.h
• linux/kthread.h
• linux/semaphore.h
• linux/uuid.h
• linux/list_sort.h
• linux/namei.h
• misc.h
• disk-io.h
• extent-tree.h
• transaction.h
• volumes.h
• raid56.h
• dev-replace.h
• sysfs.h
• tree-checker.h
• space-info.h
• block-group.h
• discard.h
• zoned.h
• fs.h
• accessors.h
• uuid-tree.h
• ioctl.h
• relocation.h
• scrub.h
• super.h
• raid-stripe-tree.h

Detected Declarations

• struct btrfs_io_geometry
• struct remap_chunk_info
• struct alloc_chunk_ctl
• struct stripe_mirror
• function flags
• function btrfs_nr_parity_stripes
• function btrfs_describe_block_groups
• function btrfs_get_fs_uuids
• function kfree
• function btrfs_free_device
• function free_fs_devices
• function btrfs_cleanup_fs_uuids
• function match_fsid_fs_devices
• function btrfs_get_bdev_and_sb
• function devices
• function list_for_each_entry_safe
• function list_for_each_entry
• function btrfs_open_one_device
• function is_same_device
• function list_for_each_entry
• function __btrfs_free_extra_devids
• function btrfs_free_extra_devids
• function btrfs_close_bdev
• function btrfs_close_one_device
• function close_fs_devices
• function btrfs_close_devices
• function list_for_each_entry_safe
• function open_fs_devices
• function list_for_each_entry_safe
• function devid_cmp
• function btrfs_open_devices
• function btrfs_release_disk_super
• function btrfs_super_bytenr
• function btrfs_forget_devices
• function btrfs_skip_registration
• function list_for_each_entry
• function btrfs_first_pending_extent
• function btrfs_find_hole_in_pending_extents
• function dev_extent_search_start
• function dev_extent_hole_check_zoned
• function regular
• function find_free_dev_extent
• function btrfs_free_dev_extent
• function find_next_chunk
• function find_next_devid
• function btrfs_add_dev_item
• function update_dev_time
• function btrfs_rm_dev_item

Annotated Snippet

struct btrfs_io_geometry {
	u32 stripe_index;
	u32 stripe_nr;
	int mirror_num;
	int num_stripes;
	u64 stripe_offset;
	u64 raid56_full_stripe_start;
	int max_errors;
	enum btrfs_map_op op;
	bool use_rst;
};

const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
	[BTRFS_RAID_RAID10] = {
		.sub_stripes	= 2,
		.dev_stripes	= 1,
		.devs_max	= 0,	/* 0 == as many as possible */
		.devs_min	= 2,
		.tolerated_failures = 1,
		.devs_increment	= 2,
		.ncopies	= 2,
		.nparity        = 0,
		.raid_name	= "raid10",
		.bg_flag	= BTRFS_BLOCK_GROUP_RAID10,
		.mindev_error	= BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
	},
	[BTRFS_RAID_RAID1] = {
		.sub_stripes	= 1,
		.dev_stripes	= 1,
		.devs_max	= 2,
		.devs_min	= 2,
		.tolerated_failures = 1,
		.devs_increment	= 2,
		.ncopies	= 2,
		.nparity        = 0,
		.raid_name	= "raid1",
		.bg_flag	= BTRFS_BLOCK_GROUP_RAID1,
		.mindev_error	= BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
	},
	[BTRFS_RAID_RAID1C3] = {
		.sub_stripes	= 1,
		.dev_stripes	= 1,
		.devs_max	= 3,
		.devs_min	= 3,
		.tolerated_failures = 2,
		.devs_increment	= 3,
		.ncopies	= 3,
		.nparity        = 0,
		.raid_name	= "raid1c3",
		.bg_flag	= BTRFS_BLOCK_GROUP_RAID1C3,
		.mindev_error	= BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET,
	},
	[BTRFS_RAID_RAID1C4] = {
		.sub_stripes	= 1,
		.dev_stripes	= 1,
		.devs_max	= 4,
		.devs_min	= 4,
		.tolerated_failures = 3,
		.devs_increment	= 4,
		.ncopies	= 4,
		.nparity        = 0,
		.raid_name	= "raid1c4",
		.bg_flag	= BTRFS_BLOCK_GROUP_RAID1C4,
		.mindev_error	= BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET,
	},
	[BTRFS_RAID_DUP] = {
		.sub_stripes	= 1,
		.dev_stripes	= 2,
		.devs_max	= 1,
		.devs_min	= 1,
		.tolerated_failures = 0,
		.devs_increment	= 1,
		.ncopies	= 2,
		.nparity        = 0,
		.raid_name	= "dup",
		.bg_flag	= BTRFS_BLOCK_GROUP_DUP,
		.mindev_error	= 0,
	},
	[BTRFS_RAID_RAID0] = {
		.sub_stripes	= 1,
		.dev_stripes	= 1,
		.devs_max	= 0,
		.devs_min	= 1,
		.tolerated_failures = 0,
		.devs_increment	= 1,
		.ncopies	= 1,
		.nparity        = 0,
		.raid_name	= "raid0",
		.bg_flag	= BTRFS_BLOCK_GROUP_RAID0,
		.mindev_error	= 0,

Annotation

• Immediate include surface: `linux/sched.h`, `linux/sched/mm.h`, `linux/slab.h`, `linux/ratelimit.h`, `linux/kthread.h`, `linux/semaphore.h`, `linux/uuid.h`, `linux/list_sort.h`.
• Detected declarations: `struct btrfs_io_geometry`, `struct remap_chunk_info`, `struct alloc_chunk_ctl`, `struct stripe_mirror`, `function flags`, `function btrfs_nr_parity_stripes`, `function btrfs_describe_block_groups`, `function btrfs_get_fs_uuids`, `function kfree`, `function btrfs_free_device`.
• Atlas domain: Core OS / VFS And Filesystem Core.
• Implementation status: source implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.