fs/btrfs/fs.c

File Facts

System

Linux kernel

Corpus path

fs/btrfs/fs.c

Extension

.c

Size

9539 bytes

Lines

348

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.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/crc32.h
• messages.h
• fs.h
• accessors.h
• volumes.h

Detected Declarations

• function btrfs_csum_type_size
• function btrfs_super_csum_size
• function btrfs_get_num_csums
• function btrfs_csum
• function btrfs_csum_init
• function btrfs_csum_update
• function btrfs_csum_final
• function btrfs_supported_blocksize
• function btrfs_exclop_start
• function btrfs_exclop_finish
• function btrfs_exclop_start_unlock
• function btrfs_exclop_finish
• function btrfs_exclop_balance
• function __btrfs_set_fs_incompat
• function __btrfs_clear_fs_incompat
• function __btrfs_set_fs_compat_ro
• function __btrfs_clear_fs_compat_ro

Annotated Snippet

if (!(features & flag)) {
			features |= flag;
			btrfs_set_super_incompat_flags(disk_super, features);
			btrfs_info(fs_info,
				"setting incompat feature flag for %s (0x%llx)",
				name, flag);
		}
		spin_unlock(&fs_info->super_lock);
		set_bit(BTRFS_FS_FEATURE_CHANGED, &fs_info->flags);
	}
}

void __btrfs_clear_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag,
			       const char *name)
{
	struct btrfs_super_block *disk_super;
	u64 features;

	disk_super = fs_info->super_copy;
	features = btrfs_super_incompat_flags(disk_super);
	if (features & flag) {
		spin_lock(&fs_info->super_lock);
		features = btrfs_super_incompat_flags(disk_super);
		if (features & flag) {
			features &= ~flag;
			btrfs_set_super_incompat_flags(disk_super, features);
			btrfs_info(fs_info,
				"clearing incompat feature flag for %s (0x%llx)",
				name, flag);
		}
		spin_unlock(&fs_info->super_lock);
		set_bit(BTRFS_FS_FEATURE_CHANGED, &fs_info->flags);
	}
}

void __btrfs_set_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
			      const char *name)
{
	struct btrfs_super_block *disk_super;
	u64 features;

	disk_super = fs_info->super_copy;
	features = btrfs_super_compat_ro_flags(disk_super);
	if (!(features & flag)) {
		spin_lock(&fs_info->super_lock);
		features = btrfs_super_compat_ro_flags(disk_super);
		if (!(features & flag)) {
			features |= flag;
			btrfs_set_super_compat_ro_flags(disk_super, features);
			btrfs_info(fs_info,
				"setting compat-ro feature flag for %s (0x%llx)",
				name, flag);
		}
		spin_unlock(&fs_info->super_lock);
		set_bit(BTRFS_FS_FEATURE_CHANGED, &fs_info->flags);
	}
}

void __btrfs_clear_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
				const char *name)
{
	struct btrfs_super_block *disk_super;
	u64 features;

	disk_super = fs_info->super_copy;
	features = btrfs_super_compat_ro_flags(disk_super);
	if (features & flag) {
		spin_lock(&fs_info->super_lock);
		features = btrfs_super_compat_ro_flags(disk_super);
		if (features & flag) {
			features &= ~flag;
			btrfs_set_super_compat_ro_flags(disk_super, features);
			btrfs_info(fs_info,
				"clearing compat-ro feature flag for %s (0x%llx)",
				name, flag);
		}
		spin_unlock(&fs_info->super_lock);
		set_bit(BTRFS_FS_FEATURE_CHANGED, &fs_info->flags);
	}
}

Annotation

• Immediate include surface: `linux/crc32.h`, `messages.h`, `fs.h`, `accessors.h`, `volumes.h`.
• Detected declarations: `function btrfs_csum_type_size`, `function btrfs_super_csum_size`, `function btrfs_get_num_csums`, `function btrfs_csum`, `function btrfs_csum_init`, `function btrfs_csum_update`, `function btrfs_csum_final`, `function btrfs_supported_blocksize`, `function btrfs_exclop_start`, `function btrfs_exclop_finish`.
• 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.