suballoc.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * suballoc.c
 *
 * metadata alloc and free
 * Inspired by ext3 block groups.
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 */

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "blockcheck.h"
#include "dlmglue.h"
#include "inode.h"
#include "journal.h"
#include "localalloc.h"
#include "suballoc.h"
#include "super.h"
#include "sysfile.h"
#include "uptodate.h"
#include "ocfs2_trace.h"

#include "buffer_head_io.h"

#define NOT_ALLOC_NEW_GROUP …
#define ALLOC_NEW_GROUP …
#define ALLOC_GROUPS_FROM_GLOBAL …

#define OCFS2_MAX_TO_STEAL …

struct ocfs2_suballoc_result { … };

static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
{ … }

static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
static int ocfs2_block_group_fill(handle_t *handle,
				  struct inode *alloc_inode,
				  struct buffer_head *bg_bh,
				  u64 group_blkno,
				  unsigned int group_clusters,
				  u16 my_chain,
				  struct ocfs2_chain_list *cl);
static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
				   struct inode *alloc_inode,
				   struct buffer_head *bh,
				   u64 max_block,
				   u64 *last_alloc_group,
				   int flags);

static int ocfs2_cluster_group_search(struct inode *inode,
				      struct buffer_head *group_bh,
				      u32 bits_wanted, u32 min_bits,
				      u64 max_block,
				      struct ocfs2_suballoc_result *res);
static int ocfs2_block_group_search(struct inode *inode,
				    struct buffer_head *group_bh,
				    u32 bits_wanted, u32 min_bits,
				    u64 max_block,
				    struct ocfs2_suballoc_result *res);
static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
				     handle_t *handle,
				     u32 bits_wanted,
				     u32 min_bits,
				     struct ocfs2_suballoc_result *res);
static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
					 int nr);
static int ocfs2_relink_block_group(handle_t *handle,
				    struct inode *alloc_inode,
				    struct buffer_head *fe_bh,
				    struct buffer_head *bg_bh,
				    struct buffer_head *prev_bg_bh,
				    u16 chain);
static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
						     u32 wanted);
static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
						   u64 bg_blkno,
						   u16 bg_bit_off);
static inline void ocfs2_block_to_cluster_group(struct inode *inode,
						u64 data_blkno,
						u64 *bg_blkno,
						u16 *bg_bit_off);
static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
					     u32 bits_wanted, u64 max_block,
					     int flags,
					     struct ocfs2_alloc_context **ac);

void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
{ … }

void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
{ … }

static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
{ … }

#define do_error …

static int ocfs2_validate_gd_self(struct super_block *sb,
				  struct buffer_head *bh,
				  int resize)
{ … }

static int ocfs2_validate_gd_parent(struct super_block *sb,
				    struct ocfs2_dinode *di,
				    struct buffer_head *bh,
				    int resize)
{ … }

#undef do_error

/*
 * This version only prints errors.  It does not fail the filesystem, and
 * exists only for resize.
 */
int ocfs2_check_group_descriptor(struct super_block *sb,
				 struct ocfs2_dinode *di,
				 struct buffer_head *bh)
{ … }

static int ocfs2_validate_group_descriptor(struct super_block *sb,
					   struct buffer_head *bh)
{ … }

int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
				u64 gd_blkno, struct buffer_head **bh)
{ … }

static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
					  struct ocfs2_group_desc *bg,
					  struct ocfs2_chain_list *cl,
					  u64 p_blkno, unsigned int clusters)
{ … }

static int ocfs2_block_group_fill(handle_t *handle,
				  struct inode *alloc_inode,
				  struct buffer_head *bg_bh,
				  u64 group_blkno,
				  unsigned int group_clusters,
				  u16 my_chain,
				  struct ocfs2_chain_list *cl)
{ … }

static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
{ … }

static struct buffer_head *
ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
			       struct inode *alloc_inode,
			       struct ocfs2_alloc_context *ac,
			       struct ocfs2_chain_list *cl)
{ … }

static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
					handle_t *handle,
					struct ocfs2_alloc_context *ac,
					unsigned int min_bits,
					u32 *bit_off, u32 *num_bits)
{ … }

static int ocfs2_block_group_grow_discontig(handle_t *handle,
					    struct inode *alloc_inode,
					    struct buffer_head *bg_bh,
					    struct ocfs2_alloc_context *ac,
					    struct ocfs2_chain_list *cl,
					    unsigned int min_bits)
{ … }

static void ocfs2_bg_alloc_cleanup(handle_t *handle,
				   struct ocfs2_alloc_context *cluster_ac,
				   struct inode *alloc_inode,
				   struct buffer_head *bg_bh)
{ … }

static struct buffer_head *
ocfs2_block_group_alloc_discontig(handle_t *handle,
				  struct inode *alloc_inode,
				  struct ocfs2_alloc_context *ac,
				  struct ocfs2_chain_list *cl)
{ … }

/*
 * We expect the block group allocator to already be locked.
 */
static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
				   struct inode *alloc_inode,
				   struct buffer_head *bh,
				   u64 max_block,
				   u64 *last_alloc_group,
				   int flags)
{ … }

static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
				       struct ocfs2_alloc_context *ac,
				       int type,
				       u32 slot,
				       u64 *last_alloc_group,
				       int flags)
{ … }

static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
{ … }

static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
{ … }

void ocfs2_init_steal_slots(struct ocfs2_super *osb)
{ … }

static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
{ … }

static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
{ … }

static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
{ … }

static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
{ … }

static int ocfs2_steal_resource(struct ocfs2_super *osb,
				struct ocfs2_alloc_context *ac,
				int type)
{ … }

static int ocfs2_steal_inode(struct ocfs2_super *osb,
			     struct ocfs2_alloc_context *ac)
{ … }

static int ocfs2_steal_meta(struct ocfs2_super *osb,
			    struct ocfs2_alloc_context *ac)
{ … }

int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
				      int blocks,
				      struct ocfs2_alloc_context **ac)
{ … }

int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
			       struct ocfs2_extent_list *root_el,
			       struct ocfs2_alloc_context **ac)
{ … }

int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
			    struct ocfs2_alloc_context **ac)
{ … }

/* local alloc code has to do the same thing, so rather than do this
 * twice.. */
int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
				      struct ocfs2_alloc_context *ac)
{ … }

/* Callers don't need to care which bitmap (local alloc or main) to
 * use so we figure it out for them, but unfortunately this clutters
 * things a bit. */
static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
					     u32 bits_wanted, u64 max_block,
					     int flags,
					     struct ocfs2_alloc_context **ac)
{ … }

int ocfs2_reserve_clusters(struct ocfs2_super *osb,
			   u32 bits_wanted,
			   struct ocfs2_alloc_context **ac)
{ … }

/*
 * More or less lifted from ext3. I'll leave their description below:
 *
 * "For ext3 allocations, we must not reuse any blocks which are
 * allocated in the bitmap buffer's "last committed data" copy.  This
 * prevents deletes from freeing up the page for reuse until we have
 * committed the delete transaction.
 *
 * If we didn't do this, then deleting something and reallocating it as
 * data would allow the old block to be overwritten before the
 * transaction committed (because we force data to disk before commit).
 * This would lead to corruption if we crashed between overwriting the
 * data and committing the delete.
 *
 * @@@ We may want to make this allocation behaviour conditional on
 * data-writes at some point, and disable it for metadata allocations or
 * sync-data inodes."
 *
 * Note: OCFS2 already does this differently for metadata vs data
 * allocations, as those bitmaps are separate and undo access is never
 * called on a metadata group descriptor.
 */
static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
					 int nr)
{ … }

u16 ocfs2_find_max_contig_free_bits(void *bitmap,
			 u16 total_bits, u16 start)
{ … }

static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
					     struct buffer_head *bg_bh,
					     unsigned int bits_wanted,
					     unsigned int total_bits,
					     struct ocfs2_suballoc_result *res)
{ … }

int ocfs2_block_group_set_bits(handle_t *handle,
					     struct inode *alloc_inode,
					     struct ocfs2_group_desc *bg,
					     struct buffer_head *group_bh,
					     unsigned int bit_off,
					     unsigned int num_bits,
					     unsigned int max_contig_bits,
					     int fastpath)
{ … }

/* find the one with the most empty bits */
static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
{ … }

static int ocfs2_relink_block_group(handle_t *handle,
				    struct inode *alloc_inode,
				    struct buffer_head *fe_bh,
				    struct buffer_head *bg_bh,
				    struct buffer_head *prev_bg_bh,
				    u16 chain)
{ … }

static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
						     u32 wanted)
{ … }

/* return 0 on success, -ENOSPC to keep searching and any other < 0
 * value on error. */
static int ocfs2_cluster_group_search(struct inode *inode,
				      struct buffer_head *group_bh,
				      u32 bits_wanted, u32 min_bits,
				      u64 max_block,
				      struct ocfs2_suballoc_result *res)
{ … }

static int ocfs2_block_group_search(struct inode *inode,
				    struct buffer_head *group_bh,
				    u32 bits_wanted, u32 min_bits,
				    u64 max_block,
				    struct ocfs2_suballoc_result *res)
{ … }

int ocfs2_alloc_dinode_update_counts(struct inode *inode,
				       handle_t *handle,
				       struct buffer_head *di_bh,
				       u32 num_bits,
				       u16 chain)
{ … }

void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
				       struct buffer_head *di_bh,
				       u32 num_bits,
				       u16 chain)
{ … }

static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
					 struct ocfs2_extent_rec *rec,
					 struct ocfs2_chain_list *cl)
{ … }

static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
					  struct ocfs2_group_desc *bg,
					  struct ocfs2_suballoc_result *res)
{ … }

static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
				  handle_t *handle,
				  u32 bits_wanted,
				  u32 min_bits,
				  struct ocfs2_suballoc_result *res,
				  u16 *bits_left)
{ … }

static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
			      handle_t *handle,
			      u32 bits_wanted,
			      u32 min_bits,
			      struct ocfs2_suballoc_result *res,
			      u16 *bits_left)
{ … }

/* will give out up to bits_wanted contiguous bits. */
static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
				     handle_t *handle,
				     u32 bits_wanted,
				     u32 min_bits,
				     struct ocfs2_suballoc_result *res)
{ … }

int ocfs2_claim_metadata(handle_t *handle,
			 struct ocfs2_alloc_context *ac,
			 u32 bits_wanted,
			 u64 *suballoc_loc,
			 u16 *suballoc_bit_start,
			 unsigned int *num_bits,
			 u64 *blkno_start)
{ … }

static void ocfs2_init_inode_ac_group(struct inode *dir,
				      struct buffer_head *parent_di_bh,
				      struct ocfs2_alloc_context *ac)
{ … }

static inline void ocfs2_save_inode_ac_group(struct inode *dir,
					     struct ocfs2_alloc_context *ac)
{ … }

int ocfs2_find_new_inode_loc(struct inode *dir,
			     struct buffer_head *parent_fe_bh,
			     struct ocfs2_alloc_context *ac,
			     u64 *fe_blkno)
{ … }

int ocfs2_claim_new_inode_at_loc(handle_t *handle,
				 struct inode *dir,
				 struct ocfs2_alloc_context *ac,
				 u64 *suballoc_loc,
				 u16 *suballoc_bit,
				 u64 di_blkno)
{ … }

int ocfs2_claim_new_inode(handle_t *handle,
			  struct inode *dir,
			  struct buffer_head *parent_fe_bh,
			  struct ocfs2_alloc_context *ac,
			  u64 *suballoc_loc,
			  u16 *suballoc_bit,
			  u64 *fe_blkno)
{ … }

/* translate a group desc. blkno and it's bitmap offset into
 * disk cluster offset. */
static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
						   u64 bg_blkno,
						   u16 bg_bit_off)
{ … }

/* given a cluster offset, calculate which block group it belongs to
 * and return that block offset. */
u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
{ … }

/* given the block number of a cluster start, calculate which cluster
 * group and descriptor bitmap offset that corresponds to. */
static inline void ocfs2_block_to_cluster_group(struct inode *inode,
						u64 data_blkno,
						u64 *bg_blkno,
						u16 *bg_bit_off)
{ … }

/*
 * min_bits - minimum contiguous chunk from this total allocation we
 * can handle. set to what we asked for originally for a full
 * contig. allocation, set to '1' to indicate we can deal with extents
 * of any size.
 */
int __ocfs2_claim_clusters(handle_t *handle,
			   struct ocfs2_alloc_context *ac,
			   u32 min_clusters,
			   u32 max_clusters,
			   u32 *cluster_start,
			   u32 *num_clusters)
{ … }

int ocfs2_claim_clusters(handle_t *handle,
			 struct ocfs2_alloc_context *ac,
			 u32 min_clusters,
			 u32 *cluster_start,
			 u32 *num_clusters)
{ … }

static int ocfs2_block_group_clear_bits(handle_t *handle,
					struct inode *alloc_inode,
					struct ocfs2_group_desc *bg,
					struct buffer_head *group_bh,
					unsigned int bit_off,
					unsigned int num_bits,
					unsigned int max_contig_bits,
					void (*undo_fn)(unsigned int bit,
							unsigned long *bmap))
{ … }

/*
 * expects the suballoc inode to already be locked.
 */
static int _ocfs2_free_suballoc_bits(handle_t *handle,
				     struct inode *alloc_inode,
				     struct buffer_head *alloc_bh,
				     unsigned int start_bit,
				     u64 bg_blkno,
				     unsigned int count,
				     void (*undo_fn)(unsigned int bit,
						     unsigned long *bitmap))
{ … }

int ocfs2_free_suballoc_bits(handle_t *handle,
			     struct inode *alloc_inode,
			     struct buffer_head *alloc_bh,
			     unsigned int start_bit,
			     u64 bg_blkno,
			     unsigned int count)
{ … }

int ocfs2_free_dinode(handle_t *handle,
		      struct inode *inode_alloc_inode,
		      struct buffer_head *inode_alloc_bh,
		      struct ocfs2_dinode *di)
{ … }

static int _ocfs2_free_clusters(handle_t *handle,
				struct inode *bitmap_inode,
				struct buffer_head *bitmap_bh,
				u64 start_blk,
				unsigned int num_clusters,
				void (*undo_fn)(unsigned int bit,
						unsigned long *bitmap))
{ … }

int ocfs2_free_clusters(handle_t *handle,
			struct inode *bitmap_inode,
			struct buffer_head *bitmap_bh,
			u64 start_blk,
			unsigned int num_clusters)
{ … }

/*
 * Give never-used clusters back to the global bitmap.  We don't need
 * to protect these bits in the undo buffer.
 */
int ocfs2_release_clusters(handle_t *handle,
			   struct inode *bitmap_inode,
			   struct buffer_head *bitmap_bh,
			   u64 start_blk,
			   unsigned int num_clusters)
{ … }

/*
 * For a given allocation, determine which allocators will need to be
 * accessed, and lock them, reserving the appropriate number of bits.
 *
 * Sparse file systems call this from ocfs2_write_begin_nolock()
 * and ocfs2_allocate_unwritten_extents().
 *
 * File systems which don't support holes call this from
 * ocfs2_extend_allocation().
 */
int ocfs2_lock_allocators(struct inode *inode,
			  struct ocfs2_extent_tree *et,
			  u32 clusters_to_add, u32 extents_to_split,
			  struct ocfs2_alloc_context **data_ac,
			  struct ocfs2_alloc_context **meta_ac)
{ … }

/*
 * Read the inode specified by blkno to get suballoc_slot and
 * suballoc_bit.
 */
static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
				       u16 *suballoc_slot, u64 *group_blkno,
				       u16 *suballoc_bit)
{ … }

/*
 * test whether bit is SET in allocator bitmap or not.  on success, 0
 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
 * is returned and *res is meaningless.  Call this after you have
 * cluster locked against suballoc, or you may get a result based on
 * non-up2date contents
 */
static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
				   struct inode *suballoc,
				   struct buffer_head *alloc_bh,
				   u64 group_blkno, u64 blkno,
				   u16 bit, int *res)
{ … }

/*
 * Test if the bit representing this inode (blkno) is set in the
 * suballocator.
 *
 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
 *
 * In the event of failure, a negative value is returned and *res is
 * meaningless.
 *
 * Callers must make sure to hold nfs_sync_lock to prevent
 * ocfs2_delete_inode() on another node from accessing the same
 * suballocator concurrently.
 */
int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
{ … }
linux/fs/ocfs2/suballoc.c
