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spaceman.c
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spaceman.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2019 Ernesto A. Fernández <[email protected]>
*/
#include <linux/buffer_head.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include "apfs.h"
/**
* apfs_spaceman_read_cib_addr - Get the address of a cib from the spaceman
* @sb: superblock structure
* @index: index of the chunk-info block
*
* Returns the block number for the chunk-info block.
*
* This is not described in the official documentation; credit for figuring it
* out should go to Joachim Metz: <https://github.com/libyal/libfsapfs>.
*/
static u64 apfs_spaceman_read_cib_addr(struct super_block *sb, int index)
{
struct apfs_spaceman *sm = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = sm->sm_raw;
u32 offset;
__le64 *addr_p;
offset = sm->sm_addr_offset + index * sizeof(*addr_p);
addr_p = (void *)sm_raw + offset;
return le64_to_cpup(addr_p);
}
/**
* apfs_spaceman_write_cib_addr - Store the address of a cib in the spaceman
* @sb: superblock structure
* @index: index of the chunk-info block
* @addr: address of the chunk-info block
*/
static void apfs_spaceman_write_cib_addr(struct super_block *sb,
int index, u64 addr)
{
struct apfs_spaceman *sm = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = sm->sm_raw;
u32 offset;
__le64 *addr_p;
apfs_assert_in_transaction(sb, &sm_raw->sm_o);
offset = sm->sm_addr_offset + index * sizeof(*addr_p);
addr_p = (void *)sm_raw + offset;
*addr_p = cpu_to_le64(addr);
}
/**
* apfs_max_chunks_per_cib - Find the maximum chunk count for a chunk-info block
* @sb: superblock structure
*/
static inline int apfs_max_chunks_per_cib(struct super_block *sb)
{
return (sb->s_blocksize - sizeof(struct apfs_chunk_info_block)) /
sizeof(struct apfs_chunk_info);
}
/**
* apfs_read_spaceman_dev - Read a space manager device structure
* @sb: superblock structure
* @dev: on-disk device structure
*
* Initializes the in-memory spaceman fields related to the main device; fusion
* drives are not yet supported. Returns 0 on success, or a negative error code
* in case of failure.
*/
static int apfs_read_spaceman_dev(struct super_block *sb,
struct apfs_spaceman_device *dev)
{
struct apfs_spaceman *spaceman = APFS_SM(sb);
if (dev->sm_cab_count) {
apfs_err(sb, "large devices are not supported");
return -EINVAL;
}
spaceman->sm_block_count = le64_to_cpu(dev->sm_block_count);
spaceman->sm_chunk_count = le64_to_cpu(dev->sm_chunk_count);
spaceman->sm_cib_count = le32_to_cpu(dev->sm_cib_count);
spaceman->sm_free_count = le64_to_cpu(dev->sm_free_count);
spaceman->sm_addr_offset = le32_to_cpu(dev->sm_addr_offset);
/* Check that all the cib addresses fit in the spaceman object */
if ((long long)spaceman->sm_addr_offset +
(long long)spaceman->sm_cib_count * sizeof(u64) > spaceman->sm_size) {
apfs_err(sb, "too many cibs (%u)", spaceman->sm_cib_count);
return -EFSCORRUPTED;
}
return 0;
}
/**
* apfs_spaceman_get_16 - Get a 16-bit value from an offset in the spaceman
* @sb: superblock structure
* @off: offset for the value
*
* Returns a pointer to the value, or NULL if it doesn't fit.
*/
static __le16 *apfs_spaceman_get_16(struct super_block *sb, size_t off)
{
struct apfs_spaceman *spaceman = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = spaceman->sm_raw;
if (off > spaceman->sm_size)
return NULL;
if (off + sizeof(__le16) > spaceman->sm_size)
return NULL;
return (void *)sm_raw + off;
}
/**
* apfs_spaceman_get_64 - Get a 64-bit value from an offset in the spaceman
* @sb: superblock structure
* @off: offset for the value
*
* Returns a pointer to the value, or NULL if it doesn't fit.
*/
static __le64 *apfs_spaceman_get_64(struct super_block *sb, size_t off)
{
struct apfs_spaceman *spaceman = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = spaceman->sm_raw;
if (off > spaceman->sm_size)
return NULL;
if (off + sizeof(__le64) > spaceman->sm_size)
return NULL;
return (void *)sm_raw + off;
}
/**
* apfs_ip_bm_is_free - Check if a given ip bitmap is in the free range
* @sm: on-disk spaceman structure
* @index: offset in the ring buffer of the bitmap block to check
*/
static bool apfs_ip_bm_is_free(struct apfs_spaceman_phys *sm, u16 index)
{
u16 free_head = le16_to_cpu(sm->sm_ip_bm_free_head);
u16 free_tail = le16_to_cpu(sm->sm_ip_bm_free_tail);
u16 free_len, index_in_free;
u16 bmap_count = le32_to_cpu(sm->sm_ip_bm_block_count);
free_len = (bmap_count + free_tail - free_head) % bmap_count;
index_in_free = (bmap_count + index - free_head) % bmap_count;
return index_in_free < free_len;
}
/**
* apfs_update_ip_bm_free_next - Update free_next for the internal pool
* @sb: superblock structure
*
* Uses the head and tail reported by the on-disk spaceman structure. Returns 0
* on success, or -EFSCORRUPTED if corruption is detected.
*/
static int apfs_update_ip_bm_free_next(struct super_block *sb)
{
struct apfs_spaceman *spaceman = APFS_SM(sb);
struct apfs_spaceman_phys *raw = spaceman->sm_raw;
u32 free_next_off = le32_to_cpu(raw->sm_ip_bm_free_next_offset);
int bmap_count = le32_to_cpu(raw->sm_ip_bm_block_count); /* TODO: this can overflow! */
__le16 *free_next;
int i;
if (free_next_off > spaceman->sm_size) {
apfs_err(sb, "offset out of bounds (%u)", free_next_off);
return -EFSCORRUPTED;
}
if (free_next_off + bmap_count * sizeof(*free_next) > spaceman->sm_size) {
apfs_err(sb, "free next out of bounds (%u-%u)", free_next_off, bmap_count * (u32)sizeof(*free_next));
return -EFSCORRUPTED;
}
free_next = (void *)raw + free_next_off;
for (i = 0; i < bmap_count; ++i) {
if (apfs_ip_bm_is_free(raw, i))
free_next[i] = cpu_to_le16((1 + i) % bmap_count);
else
free_next[i] = cpu_to_le16(0xFFFF);
}
return 0;
}
/**
* apfs_rotate_single_ip_bitmap - Reallocate an ip bmap in the circular buffer
* @sb: filesystem superblock
* @idx: index of the ip bitmap to reallocate
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_rotate_single_ip_bitmap(struct super_block *sb, u32 idx)
{
struct apfs_nxsb_info *nxi = APFS_NXI(sb);
struct apfs_spaceman *spaceman = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = spaceman->sm_raw;
struct buffer_head *old_bh = NULL, *new_bh = NULL;
u64 ring_base;
u32 ring_length;
u32 xid_off, ip_bitmap_off;
u64 ip_bitmap_bno;
u16 free_head;
__le64 *xid_p = NULL;
__le16 *ip_bitmap_p = NULL;
int err;
ring_base = le64_to_cpu(sm_raw->sm_ip_bm_base);
ring_length = le32_to_cpu(sm_raw->sm_ip_bm_block_count);
free_head = le16_to_cpu(sm_raw->sm_ip_bm_free_head);
xid_off = le32_to_cpu(sm_raw->sm_ip_bm_xid_offset) + idx * sizeof(*xid_p);
xid_p = apfs_spaceman_get_64(sb, xid_off);
if (!xid_p) {
apfs_err(sb, "xid out of bounds (%u)", xid_off);
return -EFSCORRUPTED;
}
*xid_p = cpu_to_le64(nxi->nx_xid);
ip_bitmap_off = le32_to_cpu(sm_raw->sm_ip_bitmap_offset) + idx * sizeof(*ip_bitmap_p);
ip_bitmap_p = apfs_spaceman_get_16(sb, ip_bitmap_off);
if (!ip_bitmap_p) {
apfs_err(sb, "bmap offset out of bounds (%u)", ip_bitmap_off);
return -EFSCORRUPTED;
}
ip_bitmap_bno = ring_base + le16_to_cpup(ip_bitmap_p);
old_bh = apfs_sb_bread(sb, ip_bitmap_bno);
if (!old_bh) {
apfs_err(sb, "failed to read current ip bitmap (0x%llx)", ip_bitmap_bno);
return -EIO;
}
*ip_bitmap_p = cpu_to_le16(free_head);
free_head = (free_head + 1) % ring_length;
sm_raw->sm_ip_bm_free_head = cpu_to_le16(free_head);
ip_bitmap_bno = ring_base + le16_to_cpup(ip_bitmap_p);
new_bh = apfs_getblk(sb, ip_bitmap_bno);
if (!new_bh) {
apfs_err(sb, "failed to map block for CoW (0x%llx)", ip_bitmap_bno);
err = -EIO;
goto out;
}
memcpy(new_bh->b_data, old_bh->b_data, sb->s_blocksize);
err = apfs_transaction_join(sb, new_bh);
if (err)
goto out;
spaceman->sm_ip_bmaps[idx] = new_bh;
out:
brelse(old_bh);
if (err)
brelse(new_bh);
return err;
}
/**
* apfs_rotate_ip_bitmaps - Allocate new ip bitmaps from the circular buffer
* @sb: superblock structure
*
* Allocates bitmaps for the whole internal pool at once, meaning that each
* transaction is forced to allocate one bitmap for every ~1.32 TiB of container
* size, even if they won't be needed. This seems very reasonable to me, but the
* official implementation avoids it and they may have a good reason.
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_rotate_ip_bitmaps(struct super_block *sb)
{
struct apfs_spaceman *spaceman = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = spaceman->sm_raw;
u32 ring_length = le32_to_cpu(sm_raw->sm_ip_bm_block_count);
u32 bmaps_count = spaceman->sm_ip_bmaps_count;
u16 free_head, free_tail, free_len;
int err;
u32 i;
apfs_assert_in_transaction(sb, &sm_raw->sm_o);
free_head = le16_to_cpu(sm_raw->sm_ip_bm_free_head);
free_tail = le16_to_cpu(sm_raw->sm_ip_bm_free_tail);
/*
* Check that we have enough room before doing anything. If we run out
* I may need to compact the ring using the blocks marked as 0xFFFF in
* ip_bm_free_next (TODO).
*/
free_len = (ring_length + free_tail - free_head) % ring_length;
if (free_len < bmaps_count) {
apfs_alert(sb, "full ip bitmap ring (%u < %u)", free_len, bmaps_count);
return -ENOSPC;
}
for (i = 0; i < bmaps_count; ++i) {
err = apfs_rotate_single_ip_bitmap(sb, i);
if (err) {
apfs_err(sb, "failed to rotate ip bitmap %u", i);
return err;
}
}
/* All bitmaps have been reallocated, so just free the same number */
free_tail = (free_tail + bmaps_count) % ring_length;
sm_raw->sm_ip_bm_free_tail = cpu_to_le16(free_tail);
err = apfs_update_ip_bm_free_next(sb);
if (err) {
apfs_err(sb, "failed to update bitmap ring");
return err;
}
return 0;
}
/*
* Free queue record data
*/
struct apfs_fq_rec {
u64 xid;
u64 bno;
u64 len;
};
/**
* apfs_fq_rec_from_query - Read the free queue record found by a query
* @query: the query that found the record
* @fqrec: on return, the free queue record
*
* Reads the free queue record into @fqrec and performs some basic sanity
* checks as a protection against crafted filesystems. Returns 0 on success
* or -EFSCORRUPTED otherwise.
*/
static int apfs_fq_rec_from_query(struct apfs_query *query, struct apfs_fq_rec *fqrec)
{
char *raw = query->node->object.data;
struct apfs_spaceman_free_queue_key *key;
if (query->key_len != sizeof(*key)) {
apfs_err(query->node->object.sb, "bad key length (%d)", query->key_len);
return -EFSCORRUPTED;
}
key = (struct apfs_spaceman_free_queue_key *)(raw + query->key_off);
fqrec->xid = le64_to_cpu(key->sfqk_xid);
fqrec->bno = le64_to_cpu(key->sfqk_paddr);
if (query->len == 0) {
fqrec->len = 1; /* Ghost record */
return 0;
} else if (query->len == sizeof(__le64)) {
fqrec->len = le64_to_cpup((__le64 *)(raw + query->off));
return 0;
}
apfs_err(query->node->object.sb, "bad value length (%d)", query->len);
return -EFSCORRUPTED;
}
/**
* apfs_block_in_ip - Does this block belong to the internal pool?
* @sm: in-memory spaceman structure
* @bno: block number to check
*/
static inline bool apfs_block_in_ip(struct apfs_spaceman *sm, u64 bno)
{
struct apfs_spaceman_phys *sm_raw = sm->sm_raw;
u64 start = le64_to_cpu(sm_raw->sm_ip_base);
u64 end = start + le64_to_cpu(sm_raw->sm_ip_block_count);
return bno >= start && bno < end;
}
/**
* apfs_ip_mark_free - Mark a block in the internal pool as free
* @sb: superblock structure
* @bno: block number (must belong to the ip)
*/
static int apfs_ip_mark_free(struct super_block *sb, u64 bno)
{
struct apfs_spaceman *sm = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = sm->sm_raw;
struct buffer_head *bmap_bh = NULL;
bno -= le64_to_cpu(sm_raw->sm_ip_base);
bmap_bh = sm->sm_ip_bmaps[bno >> sm->sm_ip_bmaps_shift];
__clear_bit_le(bno & sm->sm_ip_bmaps_mask, bmap_bh->b_data);
return 0;
}
/*
* apfs_main_free - Mark a regular block as free
*/
static int apfs_main_free(struct super_block *sb, u64 bno);
/**
* apfs_flush_fq_rec - Delete a single fq record and mark its blocks as free
* @root: free queue root node
* @xid: transaction to target
* @len: on return, the number of freed blocks
*
* Returns 0 on success, or a negative error code in case of failure. -ENODATA
* in particular means that there are no matching records left.
*/
static int apfs_flush_fq_rec(struct apfs_node *root, u64 xid, u64 *len)
{
struct super_block *sb = root->object.sb;
struct apfs_spaceman *sm = APFS_SM(sb);
struct apfs_query *query = NULL;
struct apfs_fq_rec fqrec = {0};
u64 bno;
int err;
query = apfs_alloc_query(root, NULL /* parent */);
if (!query)
return -ENOMEM;
apfs_init_free_queue_key(xid, 0 /* paddr */, &query->key);
query->flags |= APFS_QUERY_FREE_QUEUE | APFS_QUERY_ANY_NUMBER | APFS_QUERY_EXACT;
err = apfs_btree_query(sb, &query);
if (err) {
if (err != -ENODATA)
apfs_err(sb, "query failed for xid 0x%llx, paddr 0x%llx", xid, 0ULL);
goto fail;
}
err = apfs_fq_rec_from_query(query, &fqrec);
if (err) {
apfs_err(sb, "bad free queue rec for xid 0x%llx", xid);
goto fail;
}
for (bno = fqrec.bno; bno < fqrec.bno + fqrec.len; ++bno) {
if (apfs_block_in_ip(sm, bno))
err = apfs_ip_mark_free(sb, bno);
else
err = apfs_main_free(sb, bno);
if (err) {
apfs_err(sb, "freeing block 0x%llx failed (%d)", (unsigned long long)bno, err);
goto fail;
}
}
err = apfs_btree_remove(query);
if (err) {
apfs_err(sb, "removal failed for xid 0x%llx", xid);
goto fail;
}
*len = fqrec.len;
fail:
apfs_free_query(query);
return err;
}
/**
* apfs_free_queue_oldest_xid - Find the oldest xid among the free queue records
* @root: free queue root node
*/
static u64 apfs_free_queue_oldest_xid(struct apfs_node *root)
{
struct apfs_spaceman_free_queue_key *key;
char *raw = root->object.data;
int len, off;
if (root->records == 0)
return 0;
len = apfs_node_locate_key(root, 0, &off);
if (len != sizeof(*key)) {
/* TODO: abort transaction */
apfs_err(root->object.sb, "bad key length (%d)", len);
return 0;
}
key = (struct apfs_spaceman_free_queue_key *)(raw + off);
return le64_to_cpu(key->sfqk_xid);
}
/**
* apfs_flush_free_queue - Free ip blocks queued by old transactions
* @sb: superblock structure
* @qid: queue to be freed
* @force: flush as much as possible
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_flush_free_queue(struct super_block *sb, unsigned int qid, bool force)
{
struct apfs_nxsb_info *nxi = APFS_NXI(sb);
struct apfs_spaceman *sm = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = sm->sm_raw;
struct apfs_spaceman_free_queue *fq = &sm_raw->sm_fq[qid];
struct apfs_node *fq_root;
u64 oldest = le64_to_cpu(fq->sfq_oldest_xid);
int err;
fq_root = apfs_read_node(sb, le64_to_cpu(fq->sfq_tree_oid),
APFS_OBJ_EPHEMERAL, true /* write */);
if (IS_ERR(fq_root)) {
apfs_err(sb, "failed to read fq root 0x%llx", le64_to_cpu(fq->sfq_tree_oid));
return PTR_ERR(fq_root);
}
while (oldest) {
u64 sfq_count;
/*
* Try to preserve one transaction here. I don't really know
* what free queues are for so this is probably silly.
*/
if (force) {
if (oldest == nxi->nx_xid)
break;
} else {
if (oldest + 1 >= nxi->nx_xid)
break;
}
while (true) {
u64 count = 0;
/* Probably not very efficient... */
err = apfs_flush_fq_rec(fq_root, oldest, &count);
if (err == -ENODATA) {
err = 0;
break;
} else if (err) {
apfs_err(sb, "failed to flush fq");
goto fail;
} else {
le64_add_cpu(&fq->sfq_count, -count);
}
}
oldest = apfs_free_queue_oldest_xid(fq_root);
fq->sfq_oldest_xid = cpu_to_le64(oldest);
if (force)
continue;
/*
* Flushing a single transaction may not be enough to avoid
* running out of space in the ip, but it's probably best not
* to flush all the old transactions at once either. We use a
* harsher version of the apfs_transaction_need_commit() check,
* to make sure we won't be forced to commit again right away.
*/
sfq_count = le64_to_cpu(fq->sfq_count);
if (qid == APFS_SFQ_IP && sfq_count * 6 <= le64_to_cpu(sm_raw->sm_ip_block_count))
break;
if (qid == APFS_SFQ_MAIN && sfq_count <= APFS_TRANS_MAIN_QUEUE_MAX - 200)
break;
}
fail:
apfs_node_free(fq_root);
return err;
}
/**
* apfs_allocate_spaceman - Allocate an in-memory spaceman struct, if needed
* @sb: superblock structure
* @bmap_cnt: internal pool bitmap count
*
* Returns the spaceman and sets it in the superblock info. Also sets the fixed
* information about the ip bitmap count. On failure, returns an error pointer.
*/
static struct apfs_spaceman *apfs_allocate_spaceman(struct super_block *sb, u32 bmap_cnt)
{
struct apfs_nxsb_info *nxi = APFS_NXI(sb);
struct apfs_spaceman *spaceman = NULL;
int blk_bitcnt = sb->s_blocksize * 8;
size_t sm_size;
if (nxi->nx_spaceman)
return nxi->nx_spaceman;
/* We don't expect filesystems this big, it would be like 260 TiB */
if (bmap_cnt > 200) {
apfs_err(sb, "too many ip bitmap blocks (%u)", bmap_cnt);
return ERR_PTR(-EFSCORRUPTED);
}
sm_size = sizeof(*spaceman) + bmap_cnt * sizeof(spaceman->sm_ip_bmaps[0]);
spaceman = nxi->nx_spaceman = kzalloc(sm_size, GFP_KERNEL);
if (!spaceman)
return ERR_PTR(-ENOMEM);
spaceman->sm_nxi = nxi;
spaceman->sm_ip_bmaps_count = bmap_cnt;
spaceman->sm_ip_bmaps_mask = blk_bitcnt - 1;
spaceman->sm_ip_bmaps_shift = order_base_2(blk_bitcnt);
return spaceman;
}
/**
* apfs_read_spaceman - Find and read the space manager
* @sb: superblock structure
*
* Reads the space manager structure from disk and initializes its in-memory
* counterpart; returns 0 on success, or a negative error code in case of
* failure.
*/
int apfs_read_spaceman(struct super_block *sb)
{
struct apfs_nxsb_info *nxi = APFS_NXI(sb);
struct apfs_nx_superblock *raw_sb = nxi->nx_raw;
struct apfs_spaceman *spaceman = NULL;
struct apfs_ephemeral_object_info *sm_eph_info = NULL;
struct apfs_spaceman_phys *sm_raw;
u32 sm_flags;
u64 oid = le64_to_cpu(raw_sb->nx_spaceman_oid);
int err;
if (sb->s_flags & SB_RDONLY) /* The space manager won't be needed */
return 0;
sm_eph_info = apfs_ephemeral_object_lookup(sb, oid);
if (IS_ERR(sm_eph_info)) {
apfs_err(sb, "no spaceman object for oid 0x%llx", oid);
return PTR_ERR(sm_eph_info);
}
sm_raw = (struct apfs_spaceman_phys *)sm_eph_info->object;
sm_raw->sm_o.o_xid = cpu_to_le64(nxi->nx_xid);
spaceman = apfs_allocate_spaceman(sb, le32_to_cpu(sm_raw->sm_ip_bm_size_in_blocks));
if (IS_ERR(spaceman)) {
apfs_err(sb, "failed to allocate spaceman");
err = PTR_ERR(spaceman);
goto fail;
}
spaceman->sm_raw = sm_raw;
spaceman->sm_size = sm_eph_info->size;
spaceman->sm_free_cache_base = spaceman->sm_free_cache_blkcnt = 0;
sm_flags = le32_to_cpu(sm_raw->sm_flags);
/* Undocumented feature, but it's too common to refuse to mount */
if (sm_flags & APFS_SM_FLAG_VERSIONED)
pr_warn_once("APFS: space manager is versioned\n");
/* Only read the main device; fusion drives are not yet supported */
err = apfs_read_spaceman_dev(sb, &sm_raw->sm_dev[APFS_SD_MAIN]);
if (err) {
apfs_err(sb, "failed to read main device");
goto fail;
}
spaceman->sm_blocks_per_chunk =
le32_to_cpu(sm_raw->sm_blocks_per_chunk);
spaceman->sm_chunks_per_cib = le32_to_cpu(sm_raw->sm_chunks_per_cib);
if (spaceman->sm_chunks_per_cib > apfs_max_chunks_per_cib(sb)) {
apfs_err(sb, "too many chunks per cib (%u)", spaceman->sm_chunks_per_cib);
err = -EFSCORRUPTED;
goto fail;
}
err = apfs_rotate_ip_bitmaps(sb);
if (err) {
apfs_err(sb, "failed to rotate ip bitmaps");
goto fail;
}
err = apfs_flush_free_queue(sb, APFS_SFQ_IP, false /* force */);
if (err) {
apfs_err(sb, "failed to flush ip fq");
goto fail;
}
err = apfs_flush_free_queue(sb, APFS_SFQ_MAIN, false /* force */);
if (err) {
apfs_err(sb, "failed to flush main fq");
goto fail;
}
return 0;
fail:
spaceman->sm_raw = NULL;
return err;
}
/**
* apfs_write_spaceman - Write the in-memory spaceman fields to the disk buffer
* @sm: in-memory spaceman structure
*
* Copies the updated in-memory fields of the space manager into the on-disk
* structure; the buffer is not dirtied.
*/
static void apfs_write_spaceman(struct apfs_spaceman *sm)
{
struct apfs_spaceman_phys *sm_raw = sm->sm_raw;
struct apfs_spaceman_device *dev_raw = &sm_raw->sm_dev[APFS_SD_MAIN];
struct apfs_nxsb_info *nxi;
nxi = sm->sm_nxi;
ASSERT(le64_to_cpu(sm_raw->sm_o.o_xid) == nxi->nx_xid);
dev_raw->sm_free_count = cpu_to_le64(sm->sm_free_count);
}
/**
* apfs_ip_find_free - Find a free block inside the internal pool
* @sb: superblock structure
*
* Returns the block number for a free block, or 0 in case of corruption.
*/
static u64 apfs_ip_find_free(struct super_block *sb)
{
struct apfs_spaceman *sm = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = sm->sm_raw;
int blk_bitcnt = sb->s_blocksize * 8;
u64 full_bitcnt = le64_to_cpu(sm_raw->sm_ip_block_count);
u32 i;
for (i = 0; i < sm->sm_ip_bmaps_count; ++i) {
char *bitmap = sm->sm_ip_bmaps[i]->b_data;
u64 off_in_bmap_blk, off_in_ip;
off_in_bmap_blk = find_next_zero_bit_le(bitmap, blk_bitcnt, 0 /* offset */);
if (off_in_bmap_blk >= blk_bitcnt) /* No space in this chunk */
continue;
/* We found something, confirm that it's not outside the ip */
off_in_ip = (i << sm->sm_ip_bmaps_shift) + off_in_bmap_blk;
if (off_in_ip >= full_bitcnt)
break;
return le64_to_cpu(sm_raw->sm_ip_base) + off_in_ip;
}
apfs_err(sb, "internal pool seems full");
return 0;
}
/**
* apfs_chunk_find_free - Find a free block inside a chunk
* @sb: superblock structure
* @bitmap: allocation bitmap for the chunk, which should have free blocks
* @addr: number of the first block in the chunk
*
* Returns the block number for a free block, or 0 in case of corruption.
*/
static u64 apfs_chunk_find_free(struct super_block *sb, char *bitmap, u64 addr)
{
int bitcount = sb->s_blocksize * 8;
u64 bno;
bno = find_next_zero_bit_le(bitmap, bitcount, 0 /* offset */);
if (bno >= bitcount)
return 0;
return addr + bno;
}
/**
* apfs_ip_mark_used - Mark a block in the internal pool as used
* @sb: superblock strucuture
* @bno: block number (must belong to the ip)
*/
static void apfs_ip_mark_used(struct super_block *sb, u64 bno)
{
struct apfs_spaceman *sm = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = sm->sm_raw;
struct buffer_head *bmap_bh = NULL;
bno -= le64_to_cpu(sm_raw->sm_ip_base);
bmap_bh = sm->sm_ip_bmaps[bno >> sm->sm_ip_bmaps_shift];
__set_bit_le(bno & sm->sm_ip_bmaps_mask, bmap_bh->b_data);
}
/**
* apfs_chunk_mark_used - Mark a block inside a chunk as used
* @sb: superblock structure
* @bitmap: allocation bitmap for the chunk
* @bno: block number (must belong to the chunk)
*/
static inline void apfs_chunk_mark_used(struct super_block *sb, char *bitmap,
u64 bno)
{
int bitcount = sb->s_blocksize * 8;
__set_bit_le(bno & (bitcount - 1), bitmap);
}
/**
* apfs_chunk_mark_free - Mark a block inside a chunk as free
* @sb: superblock structure
* @bitmap: allocation bitmap for the chunk
* @bno: block number (must belong to the chunk)
*/
static inline int apfs_chunk_mark_free(struct super_block *sb, char *bitmap,
u64 bno)
{
int bitcount = sb->s_blocksize * 8;
return __test_and_clear_bit_le(bno & (bitcount - 1), bitmap);
}
/**
* apfs_free_queue_try_insert - Try to add a block range to its free queue
* @sb: superblock structure
* @bno: first block number to free
* @count: number of consecutive blocks to free
*
* Same as apfs_free_queue_insert_nocache(), except that this one can also fail
* with -EAGAIN if there is no room for the new record, so that the caller can
* flush the queue and retry.
*/
static int apfs_free_queue_try_insert(struct super_block *sb, u64 bno, u64 count)
{
struct apfs_nxsb_info *nxi = APFS_NXI(sb);
struct apfs_spaceman *sm = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = sm->sm_raw;
struct apfs_spaceman_free_queue *fq;
struct apfs_node *fq_root = NULL;
struct apfs_btree_info *fq_info = NULL;
struct apfs_query *query = NULL;
struct apfs_spaceman_free_queue_key raw_key;
bool ghost = count == 1;
int needed_room;
__le64 raw_val;
u64 node_count;
u16 node_limit;
int err;
if (apfs_block_in_ip(sm, bno))
fq = &sm_raw->sm_fq[APFS_SFQ_IP];
else
fq = &sm_raw->sm_fq[APFS_SFQ_MAIN];
fq_root = apfs_read_node(sb, le64_to_cpu(fq->sfq_tree_oid),
APFS_OBJ_EPHEMERAL, true /* write */);
if (IS_ERR(fq_root)) {
apfs_err(sb, "failed to read fq root 0x%llx", le64_to_cpu(fq->sfq_tree_oid));
return PTR_ERR(fq_root);
}
query = apfs_alloc_query(fq_root, NULL /* parent */);
if (!query) {
err = -ENOMEM;
goto fail;
}
apfs_init_free_queue_key(nxi->nx_xid, bno, &query->key);
query->flags |= APFS_QUERY_FREE_QUEUE;
err = apfs_btree_query(sb, &query);
if (err && err != -ENODATA) {
apfs_err(sb, "query failed for xid 0x%llx, paddr 0x%llx", nxi->nx_xid, bno);
goto fail;
}
fq_info = (void *)fq_root->object.data + sb->s_blocksize - sizeof(*fq_info);
node_count = le64_to_cpu(fq_info->bt_node_count);
node_limit = le16_to_cpu(fq->sfq_tree_node_limit);
if (node_count == node_limit) {
needed_room = sizeof(raw_key) + (ghost ? 0 : sizeof(raw_val));
if (!apfs_node_has_room(query->node, needed_room, false /* replace */)) {
err = -EAGAIN;
goto fail;
}
}
raw_key.sfqk_xid = cpu_to_le64(nxi->nx_xid);
raw_key.sfqk_paddr = cpu_to_le64(bno);
if (ghost) {
/* A lack of value (ghost record) means single-block extent */
err = apfs_btree_insert(query, &raw_key, sizeof(raw_key), NULL /* val */, 0 /* val_len */);
} else {
raw_val = cpu_to_le64(count);
err = apfs_btree_insert(query, &raw_key, sizeof(raw_key), &raw_val, sizeof(raw_val));
}
if (err) {
apfs_err(sb, "insertion failed for xid 0x%llx, paddr 0x%llx", nxi->nx_xid, bno);
goto fail;
}
if (!fq->sfq_oldest_xid)
fq->sfq_oldest_xid = cpu_to_le64(nxi->nx_xid);
le64_add_cpu(&fq->sfq_count, count);
fail:
apfs_free_query(query);
apfs_node_free(fq_root);
return err;
}
/**
* apfs_free_queue_insert_nocache - Add a block range to its free queue
* @sb: superblock structure
* @bno: first block number to free
* @count: number of consecutive blocks to free
*
* Same as apfs_free_queue_insert(), but writes to the free queue directly,
* bypassing the cache of the latest freed block range.
*
* Returns 0 on success or a negative error code in case of failure.
*/
int apfs_free_queue_insert_nocache(struct super_block *sb, u64 bno, u64 count)
{
struct apfs_spaceman *sm = APFS_SM(sb);
unsigned int qid;
int err;
err = apfs_free_queue_try_insert(sb, bno, count);
if (err == -EAGAIN) {
qid = apfs_block_in_ip(sm, bno) ? APFS_SFQ_IP : APFS_SFQ_MAIN;
err = apfs_flush_free_queue(sb, qid, true /* force */);
if (err) {
apfs_err(sb, "failed to flush fq to make room");
return err;
}
err = apfs_free_queue_try_insert(sb, bno, count);
}
if (err) {
if (err == -EAGAIN) {
apfs_alert(sb, "failed to make room in fq - bug!");
err = -EFSCORRUPTED;
}
apfs_err(sb, "fq insert failed (0x%llx-0x%llx)", bno, count);
return err;
}
return 0;
}
/**
* apfs_free_queue_insert - Add a block range to its free queue
* @sb: superblock structure
* @bno: first block number to free
* @count: number of consecutive blocks to free
*
* Uses a cache to delay the actual tree operations as much as possible.
*
* Returns 0 on success or a negative error code in case of failure.
*/
int apfs_free_queue_insert(struct super_block *sb, u64 bno, u64 count)
{
struct apfs_spaceman *sm = APFS_SM(sb);
int err;
if (sm->sm_free_cache_base == 0) {
/* Nothing yet cached */
sm->sm_free_cache_base = bno;
sm->sm_free_cache_blkcnt = count;
return 0;
}
/*
* First attempt to extend the cache of freed blocks, but never cache
* a range that doesn't belong to a single free queue.
*/
if (apfs_block_in_ip(sm, bno) == apfs_block_in_ip(sm, sm->sm_free_cache_base)) {
if (bno == sm->sm_free_cache_base + sm->sm_free_cache_blkcnt) {
sm->sm_free_cache_blkcnt += count;
return 0;
}
if (bno + count == sm->sm_free_cache_base) {
sm->sm_free_cache_base -= count;
sm->sm_free_cache_blkcnt += count;
return 0;
}
}
/* Failed to extend the cache, so flush it and replace it */
err = apfs_free_queue_insert_nocache(sb, sm->sm_free_cache_base, sm->sm_free_cache_blkcnt);
if (err) {
apfs_err(sb, "fq cache flush failed (0x%llx-0x%llx)", sm->sm_free_cache_base, sm->sm_free_cache_blkcnt);
return err;
}
sm->sm_free_cache_base = bno;
sm->sm_free_cache_blkcnt = count;
return 0;
}
/**
* apfs_chunk_alloc_free - Allocate or free block in given CIB and chunk
* @sb: superblock structure
* @cib_bh: buffer head for the chunk-info block
* @index: index of this chunk's info structure inside @cib
* @bno: block number
* @is_alloc: true to allocate, false to free
*/
static int apfs_chunk_alloc_free(struct super_block *sb,
struct buffer_head **cib_bh,
int index, u64 *bno, bool is_alloc)
{
struct apfs_nxsb_info *nxi = APFS_NXI(sb);
struct apfs_spaceman *sm = APFS_SM(sb);
struct apfs_chunk_info_block *cib;
struct apfs_chunk_info *ci;
struct buffer_head *bmap_bh = NULL;
char *bmap = NULL;
bool old_cib = false;
bool old_bmap = false;
int err = 0;
cib = (struct apfs_chunk_info_block *)(*cib_bh)->b_data;
ci = &cib->cib_chunk_info[index];
/* Cibs and bitmaps from old transactions can't be modified in place */
if (le64_to_cpu(cib->cib_o.o_xid) < nxi->nx_xid)
old_cib = true;
if (le64_to_cpu(ci->ci_xid) < nxi->nx_xid)
old_bmap = true;
if (is_alloc && le32_to_cpu(ci->ci_free_count) < 1)
return -ENOSPC;