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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_allocate_ip_bitmap - Allocate a free ip bitmap block
* @sb: filesystem superblock
* @offset_p: on return, the offset from sm_ip_bm_base of the allocated block
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_allocate_ip_bitmap(struct super_block *sb, u16 *offset_p)
{
struct apfs_spaceman *spaceman = NULL;
struct apfs_spaceman_phys *sm_raw = NULL;
u32 free_next_offset, old_head_off;
u16 free_head, blkcnt;
__le16 *old_head_p = NULL;
spaceman = APFS_SM(sb);
sm_raw = spaceman->sm_raw;
free_next_offset = le32_to_cpu(sm_raw->sm_ip_bm_free_next_offset);
free_head = le16_to_cpu(sm_raw->sm_ip_bm_free_head);
blkcnt = (u16)le32_to_cpu(sm_raw->sm_ip_bm_block_count);
/*
* The "free_next" array is a linked list of free blocks that starts
* with the "free_head". Allocate this head then, and make the next
* block into the new head.
*/
old_head_off = free_next_offset + free_head * sizeof(*old_head_p);
old_head_p = apfs_spaceman_get_16(sb, old_head_off);
if (!old_head_p) {
apfs_err(sb, "free_next head offset out of bounds (%u)", old_head_off);
return -EFSCORRUPTED;
}
*offset_p = free_head;
free_head = le16_to_cpup(old_head_p);
sm_raw->sm_ip_bm_free_head = *old_head_p;
/* No longer free, no longer part of the linked list */
*old_head_p = cpu_to_le16(APFS_SPACEMAN_IP_BM_INDEX_INVALID);
/* Just a little sanity check because I've messed this up before */
if (free_head >= blkcnt || *offset_p >= blkcnt) {
apfs_err(sb, "free next list seems empty or corrupt");
return -EFSCORRUPTED;
}
return 0;
}
/**
* apfs_free_ip_bitmap - Free a used ip bitmap block
* @sb: filesystem superblock
* @offset: the offset from sm_ip_bm_base of the block to free
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_free_ip_bitmap(struct super_block *sb, u16 offset)
{
struct apfs_spaceman *spaceman = NULL;
struct apfs_spaceman_phys *sm_raw = NULL;
u32 free_next_offset, old_tail_off;
u16 free_tail;
__le16 *old_tail_p = NULL;
spaceman = APFS_SM(sb);
sm_raw = spaceman->sm_raw;
free_next_offset = le32_to_cpu(sm_raw->sm_ip_bm_free_next_offset);
free_tail = le16_to_cpu(sm_raw->sm_ip_bm_free_tail);
/*
* The "free_next" array is a linked list of free blocks that ends
* with the "free_tail". The block getting freed will become the new
* tail of the list.
*/
old_tail_off = free_next_offset + free_tail * sizeof(*old_tail_p);
old_tail_p = apfs_spaceman_get_16(sb, old_tail_off);
if (!old_tail_p) {
apfs_err(sb, "free_next tail offset out of bounds (%u)", old_tail_off);
return -EFSCORRUPTED;
}
*old_tail_p = cpu_to_le16(offset);
sm_raw->sm_ip_bm_free_tail = cpu_to_le16(offset);
free_tail = offset;
return 0;
}
/**
* apfs_reallocate_ip_bitmap - Find a new block for an ip bitmap
* @sb: filesystem superblock
* @offset_p: the offset from sm_ip_bm_base of the block to free
*
* On success returns 0 and updates @offset_p to the new offset allocated for
* the ip bitmap. Since blocks are allocated at the head of the list and freed
* at the tail, there is no risk of reuse by future reallocations within the
* same transaction (under there is some serious corruption, of course).
*
* Returns a negative error code in case of failure.
*/
static int apfs_reallocate_ip_bitmap(struct super_block *sb, __le16 *offset_p)
{
int err;
u16 offset;
offset = le16_to_cpup(offset_p);
err = apfs_free_ip_bitmap(sb, offset);
if (err) {
apfs_err(sb, "failed to free ip bitmap %u", offset);
return err;
}
err = apfs_allocate_ip_bitmap(sb, &offset);
if (err) {
apfs_err(sb, "failed to allocate a new ip bitmap block");
return err;
}
*offset_p = cpu_to_le16(offset);
return 0;
}
/**
* apfs_write_single_ip_bitmap - Write a single ip bitmap to disk
* @sb: filesystem superblock
* @bitmap: bitmap to write
* @idx: index of the ip bitmap to write
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_write_single_ip_bitmap(struct super_block *sb, char *bitmap, 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 *bh = NULL;
u64 ip_bm_base, ip_bitmap_bno;
u32 xid_off, ip_bitmap_off;
__le64 *xid_p = NULL;
__le16 *ip_bitmap_p = NULL;
int err;
ip_bm_base = le64_to_cpu(sm_raw->sm_ip_bm_base);
/* First update the xid, which is kept in a separate array */
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);
/* Now get find new location for the ip bitmap (and free the old one) */
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;
}
err = apfs_reallocate_ip_bitmap(sb, ip_bitmap_p);
if (err) {
apfs_err(sb, "failed to reallocate ip bitmap %u", le16_to_cpup(ip_bitmap_p));
return err;
}
/* Finally, write the dirty bitmap to the new location */
ip_bitmap_bno = ip_bm_base + le16_to_cpup(ip_bitmap_p);
bh = apfs_getblk(sb, ip_bitmap_bno);
if (!bh) {
apfs_err(sb, "failed to map block for CoW (0x%llx)", ip_bitmap_bno);
return -EIO;
}
memcpy(bh->b_data, bitmap, sb->s_blocksize);
err = apfs_transaction_join(sb, bh);
if (err)
goto fail;
bh = NULL;
spaceman->sm_ip_bmaps[idx].dirty = false;
return 0;
fail:
brelse(bh);
bh = NULL;
return err;
}
/**
* apfs_write_ip_bitmaps - Write all dirty ip bitmaps to disk
* @sb: superblock structure
*
* Returns 0 on success or a negative error code in case of failure.
*/
int apfs_write_ip_bitmaps(struct super_block *sb)
{
struct apfs_spaceman *spaceman = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = spaceman->sm_raw;
struct apfs_ip_bitmap_block_info *info = NULL;
u32 bmaps_count = spaceman->sm_ip_bmaps_count;
int err;
u32 i;
apfs_assert_in_transaction(sb, &sm_raw->sm_o);
for (i = 0; i < bmaps_count; ++i) {
info = &spaceman->sm_ip_bmaps[i];
if (!info->dirty)
continue;
err = apfs_write_single_ip_bitmap(sb, info->block, i);
if (err) {
apfs_err(sb, "failed to rotate ip bitmap %u", i);
return err;
}
}
return 0;
}
/**
* apfs_read_single_ip_bitmap - Read a single ip bitmap to memory
* @sb: filesystem superblock
* @idx: index of the ip bitmap to read
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_read_single_ip_bitmap(struct super_block *sb, u32 idx)
{
struct apfs_spaceman *spaceman = APFS_SM(sb);
struct apfs_spaceman_phys *sm_raw = spaceman->sm_raw;
struct buffer_head *bh = NULL;
char *bitmap = NULL;
u64 ip_bm_base, ip_bitmap_bno;
u32 ip_bitmap_off;
__le16 *ip_bitmap_p = NULL;
int err;
ip_bm_base = le64_to_cpu(sm_raw->sm_ip_bm_base);
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;
}
bitmap = kmalloc(sb->s_blocksize, GFP_KERNEL);
if (!bitmap)
return -ENOMEM;
ip_bitmap_bno = ip_bm_base + le16_to_cpup(ip_bitmap_p);
bh = apfs_sb_bread(sb, ip_bitmap_bno);
if (!bh) {
apfs_err(sb, "failed to read ip bitmap (0x%llx)", ip_bitmap_bno);
err = -EIO;
goto fail;
}
memcpy(bitmap, bh->b_data, sb->s_blocksize);
brelse(bh);
bh = NULL;
spaceman->sm_ip_bmaps[idx].dirty = false;
spaceman->sm_ip_bmaps[idx].block = bitmap;
bitmap = NULL;
return 0;
fail:
kfree(bitmap);
bitmap = NULL;
return err;
}
/**
* apfs_read_ip_bitmaps - Read all the ip bitmaps to memory
* @sb: superblock structure
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_read_ip_bitmaps(struct super_block *sb)
{
struct apfs_spaceman *spaceman = APFS_SM(sb);
u32 bmaps_count = spaceman->sm_ip_bmaps_count;
int err;
u32 i;
for (i = 0; i < bmaps_count; ++i) {
err = apfs_read_single_ip_bitmap(sb, i);
if (err) {
apfs_err(sb, "failed to read ip bitmap %u", i);
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 apfs_ip_bitmap_block_info *info = NULL;
bno -= le64_to_cpu(sm_raw->sm_ip_base);
info = &sm->sm_ip_bmaps[bno >> sm->sm_ip_bmaps_shift];
__clear_bit_le(bno & sm->sm_ip_bmaps_mask, info->block);
info->dirty = true;
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
*
* 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)
{
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;
struct apfs_btree_info *fq_info = NULL;
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) {
/*
* Blocks freed in the current transaction can't be reused
* safely until after the commit, but I don't think there is
* any point in preserving old transacions. I'm guessing the
* official driver keeps multiple transactions going at the
* same time, that must be why they need a free queue.
*/
if (oldest == 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 (qid == APFS_SFQ_MAIN) {
fq_info = (void *)fq_root->object.data + sb->s_blocksize - sizeof(*fq_info);
sm->sm_main_fq_nodes = le64_to_cpu(fq_info->bt_node_count);
if (sm->sm_main_fq_nodes != 1) {
apfs_alert(sb, "main queue wasn't flushed in full - bug!");
err = -EFSCORRUPTED;
goto fail;
}
}
fail:
apfs_node_free(fq_root);
return err;
}
/**
* apfs_allocate_spaceman - Allocate an in-memory spaceman struct, if needed
* @sb: superblock structure
* @raw: on-disk spaceman struct
* @size: size of the on-disk spaceman
*
* Returns the spaceman and sets it in the superblock info. Also performs all
* initializations for the internal pool, including reading all the ip bitmaps.
* This is a bit out of place here, but it's convenient because it has to
* happen only once.
*
* On failure, returns an error pointer.
*/
static struct apfs_spaceman *apfs_allocate_spaceman(struct super_block *sb, struct apfs_spaceman_phys *raw, u32 size)
{
struct apfs_nxsb_info *nxi = APFS_NXI(sb);
struct apfs_spaceman *spaceman = NULL;
int blk_bitcnt = sb->s_blocksize * 8;
size_t sm_size;
u32 bmap_cnt;
int err;
if (nxi->nx_spaceman)
return nxi->nx_spaceman;
/* We don't expect filesystems this big, it would be like 260 TiB */
bmap_cnt = le32_to_cpu(raw->sm_ip_bm_size_in_blocks);
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;
/*
* These two fields must be set before reading the ip bitmaps, since
* that stuff involves several variable-length arrays inside the
* spaceman object itself.
*/
spaceman->sm_raw = raw;
spaceman->sm_size = size;
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);
/* This must happen only once, so it's easier to just leave it here */
err = apfs_read_ip_bitmaps(sb);
if (err) {
apfs_err(sb, "failed to read the ip bitmaps");
kfree(spaceman);
nxi->nx_spaceman = spaceman = NULL;
return ERR_PTR(err);
}
return nxi->nx_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, sm_raw, sm_eph_info->size);
if (IS_ERR(spaceman)) {
apfs_err(sb, "failed to allocate spaceman");
err = PTR_ERR(spaceman);
goto fail;
}
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;
}
/*
* We flush free queues whole when each transaction begins, to make it
* harder for the btrees to become too unbalanced.
*/
err = apfs_flush_free_queue(sb, APFS_SFQ_IP);
if (err) {
apfs_err(sb, "failed to flush ip fq");
goto fail;
}
err = apfs_flush_free_queue(sb, APFS_SFQ_MAIN);
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].block;
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 apfs_ip_bitmap_block_info *info = NULL;
bno -= le64_to_cpu(sm_raw->sm_ip_base);
info = &sm->sm_ip_bmaps[bno >> sm->sm_ip_bmaps_shift];
__set_bit_le(bno & sm->sm_ip_bmaps_mask, info->block);
info->dirty = true;
}
/**
* 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 -ENOSPC if there is no room for the new record.
*/
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;
unsigned int qid;
int err;
qid = apfs_block_in_ip(sm, bno) ? APFS_SFQ_IP : APFS_SFQ_MAIN;
fq = &sm_raw->sm_fq[qid];
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 = -ENOSPC;
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);
if (qid == APFS_SFQ_MAIN)
sm->sm_main_fq_nodes = le64_to_cpu(fq_info->bt_node_count);
fail:
apfs_free_query(query);