fs/xfs/libxfs/xfs_ag.c
Source file repositories/reference/linux-study-clean/fs/xfs/libxfs/xfs_ag.c
File Facts
- System
- Linux kernel
- Corpus path
fs/xfs/libxfs/xfs_ag.c- Extension
.c- Size
- 25583 bytes
- Lines
- 996
- 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
xfs_platform.hxfs_fs.hxfs_shared.hxfs_format.hxfs_trans_resv.hxfs_bit.hxfs_sb.hxfs_mount.hxfs_btree.hxfs_alloc_btree.hxfs_rmap_btree.hxfs_alloc.hxfs_ialloc.hxfs_rmap.hxfs_ag.hxfs_ag_resv.hxfs_health.hxfs_error.hxfs_bmap.hxfs_defer.hxfs_log_format.hxfs_trans.hxfs_trace.hxfs_inode.hxfs_icache.hxfs_group.h
Detected Declarations
struct xfs_aghdr_grow_datafunction Copyrightfunction xfs_perag_uninitfunction xfs_free_perag_rangefunction __xfs_ag_block_countfunction xfs_ag_block_countfunction __xfs_agino_rangefunction xfs_agino_rangefunction recoveryfunction xfs_perag_allocfunction xfs_initialize_peragfunction xfs_get_aghdr_buffunction xfs_btroot_initfunction xfs_freesp_init_recsfunction xfs_bnoroot_initfunction xfs_rmaproot_initfunction xfs_sbblock_initfunction xfs_agfblock_initfunction xfs_agflblock_initfunction xfs_agiblock_initfunction xfs_ag_init_hdrfunction xfs_ag_init_headersfunction xfs_ag_shrink_spacefunction xfs_growfs_compute_agcountfunction xfs_ag_extend_spacefunction xfs_ag_get_geometry
Annotated Snippet
struct xfs_aghdr_grow_data {
xfs_daddr_t daddr;
size_t numblks;
const struct xfs_buf_ops *ops;
aghdr_init_work_f work;
const struct xfs_btree_ops *bc_ops;
bool need_init;
};
/*
* Prepare new AG headers to be written to disk. We use uncached buffers here,
* as it is assumed these new AG headers are currently beyond the currently
* valid filesystem address space. Using cached buffers would trip over EOFS
* corruption detection alogrithms in the buffer cache lookup routines.
*
* This is a non-transactional function, but the prepared buffers are added to a
* delayed write buffer list supplied by the caller so they can submit them to
* disk and wait on them as required.
*/
int
xfs_ag_init_headers(
struct xfs_mount *mp,
struct aghdr_init_data *id)
{
struct xfs_aghdr_grow_data aghdr_data[] = {
{ /* SB */
.daddr = XFS_AG_DADDR(mp, id->agno, XFS_SB_DADDR),
.numblks = XFS_FSS_TO_BB(mp, 1),
.ops = &xfs_sb_buf_ops,
.work = &xfs_sbblock_init,
.need_init = true
},
{ /* AGF */
.daddr = XFS_AG_DADDR(mp, id->agno, XFS_AGF_DADDR(mp)),
.numblks = XFS_FSS_TO_BB(mp, 1),
.ops = &xfs_agf_buf_ops,
.work = &xfs_agfblock_init,
.need_init = true
},
{ /* AGFL */
.daddr = XFS_AG_DADDR(mp, id->agno, XFS_AGFL_DADDR(mp)),
.numblks = XFS_FSS_TO_BB(mp, 1),
.ops = &xfs_agfl_buf_ops,
.work = &xfs_agflblock_init,
.need_init = true
},
{ /* AGI */
.daddr = XFS_AG_DADDR(mp, id->agno, XFS_AGI_DADDR(mp)),
.numblks = XFS_FSS_TO_BB(mp, 1),
.ops = &xfs_agi_buf_ops,
.work = &xfs_agiblock_init,
.need_init = true
},
{ /* BNO root block */
.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_BNO_BLOCK(mp)),
.numblks = BTOBB(mp->m_sb.sb_blocksize),
.ops = &xfs_bnobt_buf_ops,
.work = &xfs_bnoroot_init,
.bc_ops = &xfs_bnobt_ops,
.need_init = true
},
{ /* CNT root block */
.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_CNT_BLOCK(mp)),
.numblks = BTOBB(mp->m_sb.sb_blocksize),
.ops = &xfs_cntbt_buf_ops,
.work = &xfs_bnoroot_init,
.bc_ops = &xfs_cntbt_ops,
.need_init = true
},
{ /* INO root block */
.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_IBT_BLOCK(mp)),
.numblks = BTOBB(mp->m_sb.sb_blocksize),
.ops = &xfs_inobt_buf_ops,
.work = &xfs_btroot_init,
.bc_ops = &xfs_inobt_ops,
.need_init = true
},
{ /* FINO root block */
.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_FIBT_BLOCK(mp)),
.numblks = BTOBB(mp->m_sb.sb_blocksize),
.ops = &xfs_finobt_buf_ops,
.work = &xfs_btroot_init,
.bc_ops = &xfs_finobt_ops,
.need_init = xfs_has_finobt(mp)
},
{ /* RMAP root block */
.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_RMAP_BLOCK(mp)),
.numblks = BTOBB(mp->m_sb.sb_blocksize),
.ops = &xfs_rmapbt_buf_ops,
Annotation
- Immediate include surface: `xfs_platform.h`, `xfs_fs.h`, `xfs_shared.h`, `xfs_format.h`, `xfs_trans_resv.h`, `xfs_bit.h`, `xfs_sb.h`, `xfs_mount.h`.
- Detected declarations: `struct xfs_aghdr_grow_data`, `function Copyright`, `function xfs_perag_uninit`, `function xfs_free_perag_range`, `function __xfs_ag_block_count`, `function xfs_ag_block_count`, `function __xfs_agino_range`, `function xfs_agino_range`, `function recovery`, `function xfs_perag_alloc`.
- 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.