// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) International Business Machines Corp., 2000-2005
* Portions Copyright (C) Christoph Hellwig, 2001-2002
*/
#include <linux/blkdev.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/buffer_head.h>
#include <linux/mempool.h>
#include <linux/seq_file.h>
#include <linux/writeback.h>
#include "jfs_incore.h"
#include "jfs_superblock.h"
#include "jfs_filsys.h"
#include "jfs_metapage.h"
#include "jfs_txnmgr.h"
#include "jfs_debug.h"
#ifdef CONFIG_JFS_STATISTICS
static struct {
uint pagealloc; /* # of page allocations */
uint pagefree; /* # of page frees */
uint lockwait; /* # of sleeping lock_metapage() calls */
} mpStat;
#endif
#define metapage_locked(mp) test_bit(META_locked, &(mp)->flag)
#define trylock_metapage(mp) test_and_set_bit_lock(META_locked, &(mp)->flag)
static inline void unlock_metapage(struct metapage *mp)
{
clear_bit_unlock(META_locked, &mp->flag);
wake_up(&mp->wait);
}
static inline void __lock_metapage(struct metapage *mp)
{
DECLARE_WAITQUEUE(wait, current);
INCREMENT(mpStat.lockwait);
add_wait_queue_exclusive(&mp->wait, &wait);
do {
set_current_state(TASK_UNINTERRUPTIBLE);
if (metapage_locked(mp)) {
folio_unlock(mp->folio);
io_schedule();
folio_lock(mp->folio);
}
} while (trylock_metapage(mp));
__set_current_state(TASK_RUNNING);
remove_wait_queue(&mp->wait, &wait);
}
/*
* Must have mp->folio locked
*/
static inline void lock_metapage(struct metapage *mp)
{
if (trylock_metapage(mp))
__lock_metapage(mp);
}
#define METAPOOL_MIN_PAGES 32
static struct kmem_cache *metapage_cache;
static mempool_t *metapage_mempool;
#define MPS_PER_PAGE (PAGE_SIZE >> L2PSIZE)
#if MPS_PER_PAGE > 1
struct meta_anchor {
int mp_count;
atomic_t io_count;
blk_status_t status;
struct metapage *mp[MPS_PER_PAGE];
};
static inline struct metapage *folio_to_mp(struct folio *folio, int offset)
{
struct meta_anchor *anchor = folio->private;
if (!anchor)
return NULL;
return anchor->mp[offset >> L2PSIZE];
}
static inline int insert_metapage(struct folio *folio, struct metapage *mp)
{
struct meta_anchor *a;
int index;
int l2mp_blocks; /* log2 blocks per metapage */
a = folio->private;
if (!a) {
a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS);
if (!a)
return -ENOMEM;
folio_attach_private(folio, a);
kmap(&folio->page);
}
if (mp) {
l2mp_blocks = L2PSIZE - folio->mapping->host->i_blkbits;
index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
a->mp_count++;
a->mp[index] = mp;
}
return 0;
}
static inline void remove_metapage(struct folio *folio, struct metapage *mp)
{
struct meta_anchor *a = folio->private;
int l2mp_blocks = L2PSIZE - folio->mapping->host->i_blkbits;
int index;
index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
BUG_ON(a->mp[index] != mp);
a->mp[index] = NULL;
if (--a->mp_count == 0) {
kfree(a);
folio_detach_private(folio);
kunmap(&folio->page);
}
}
static inline void inc_io(struct folio *folio)
{
struct meta_anchor *anchor = folio->private;
atomic_inc(&anchor->io_count);
}
static inline void dec_io(struct folio *folio, blk_status_t status,
void (*handler)(struct folio *, blk_status_t))
{
struct meta_anchor *anchor = folio->private;
if (anchor->status == BLK_STS_OK)
anchor->status = status;
if (atomic_dec_and_test(&anchor->io_count))
handler(folio, anchor->status);
}
#else
static inline struct metapage *folio_to_mp(struct folio *folio, int offset)
{
return folio->private;
}
static inline int insert_metapage(struct folio *folio, struct metapage *mp)
{
if (mp) {
folio_attach_private(folio, mp);
kmap(&folio->page);
}
return 0;
}
static inline void remove_metapage(struct folio *folio, struct metapage *mp)
{
folio_detach_private(folio);
kunmap(&folio->page);
}
#define inc_io(folio) do {} while(0)
#define dec_io(folio, status, handler) handler(folio, status)
#endif
static inline struct metapage *alloc_metapage(gfp_t gfp_mask)
{
struct metapage *mp = mempool_alloc(metapage_mempool, gfp_mask);
if (mp) {
mp->lid = 0;
mp->lsn = 0;
mp->data = NULL;
mp->clsn = 0;
mp->log = NULL;
init_waitqueue_head(&mp->wait);
}
return mp;
}
static inline void free_metapage(struct metapage *mp)
{
mempool_free(mp, metapage_mempool);
}
int __init metapage_init(void)
{
/*
* Allocate the metapage structures
*/
metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage),
0, 0, NULL);
if (metapage_cache == NULL)
return -ENOMEM;
metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES,
metapage_cache);
if (metapage_mempool == NULL) {
kmem_cache_destroy(metapage_cache);
return -ENOMEM;
}
return 0;
}
void metapage_exit(void)
{
mempool_destroy(metapage_mempool);
kmem_cache_destroy(metapage_cache);
}
static inline void drop_metapage(struct folio *folio, struct metapage *mp)
{
if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
test_bit(META_io, &mp->flag))
return;
remove_metapage(folio, mp);
INCREMENT(mpStat.pagefree);
free_metapage(mp);
}
/*
* Metapage address space operations
*/
static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
int *len)
{
int rc = 0;
int xflag;
s64 xaddr;
sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
inode->i_blkbits;
if (lblock >= file_blocks)
return 0;
if (lblock + *len > file_blocks)
*len = file_blocks - lblock;
if (inode->i_ino) {
rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0);
if ((rc == 0) && *len)
lblock = (sector_t)xaddr;
else
lblock = 0;
} /* else no mapping */
return lblock;
}
static void last_read_complete(struct folio *folio, blk_status_t status)
{
if (status)
printk(KERN_ERR "Read error %d at %#llx\n", status,
folio_pos(folio));
folio_end_read(folio, status == 0);
}
static void metapage_read_end_io(struct bio *bio)
{
struct folio *folio = bio->bi_private;
dec_io(folio, bio->bi_status, last_read_complete);
bio_put(bio);
}
static void remove_from_logsync(struct metapage *mp)
{
struct jfs_log *log = mp->log;
unsigned long flags;
/*
* This can race. Recheck that log hasn't been set to null, and after
* acquiring logsync lock, recheck lsn
*/
if (!log)
return;
LOGSYNC_LOCK(log, flags);
if (mp->lsn) {
mp->log = NULL;
mp->lsn = 0;
mp->clsn = 0;
log->count--;
list_del(&mp->synclist);
}
LOGSYNC_UNLOCK(log, flags);
}
static void last_write_complete(struct folio *folio, blk_status_t status)
{
struct metapage *mp;
unsigned int offset;
if (status) {
int err = blk_status_to_errno(status);
printk(KERN_ERR "metapage_write_end_io: I/O error\n");
mapping_set_error(folio->mapping, err);
}
for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
mp = folio_to_mp(folio, offset);
if (mp && test_bit(META_io, &mp->flag)) {
if (mp->lsn)
remove_from_logsync(mp);
clear_bit(META_io, &mp->flag);
}
/*
* I'd like to call drop_metapage here, but I don't think it's
* safe unless I have the page locked
*/
}
folio_end_writeback(folio);
}
static void metapage_write_end_io(struct bio *bio)
{
struct folio *folio = bio->bi_private;
BUG_ON(!folio->private);
dec_io(folio, bio->bi_status, last_write_complete);
bio_put(bio);
}
static int metapage_write_folio(struct folio *folio,
struct writeback_control *wbc, void *unused)
{
struct bio *bio = NULL;
int block_offset; /* block offset of mp within page */
struct inode *inode = folio->mapping->host;
int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
int len;
int xlen;
struct metapage *mp;
int redirty = 0;
sector_t lblock;
int nr_underway = 0;
sector_t pblock;
sector_t next_block = 0;
sector_t page_start;
unsigned long bio_bytes = 0;
unsigned long bio_offset = 0;
int offset;
int bad_blocks = 0;
page_start = folio_pos(folio) >> inode->i_blkbits;
BUG_ON(!folio_test_locked(folio));
BUG_ON(folio_test_writeback(folio));
folio_start_writeback(folio);
for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
mp = folio_to_mp(folio, offset);
if (!mp || !test_bit(META_dirty, &mp->flag))
continue;
if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) {
redirty = 1;
/*
* Make sure this page isn't blocked indefinitely.
* If the journal isn't undergoing I/O, push it
*/
if (mp->log && !(mp->log->cflag & logGC_PAGEOUT))
jfs_flush_journal(mp->log, 0);
continue;
}
clear_bit(META_dirty, &mp->flag);
set_bit(META_io, &mp->flag);
block_offset = offset >> inode->i_blkbits;
lblock = page_start + block_offset;
if (bio) {
if (xlen && lblock == next_block) {
/* Contiguous, in memory & on disk */
len = min(xlen, blocks_per_mp);
xlen -= len;
bio_bytes += len << inode->i_blkbits;
continue;
}
/* Not contiguous */
bio_add_folio_nofail(bio, folio, bio_bytes, bio_offset);
/*
* Increment counter before submitting i/o to keep
* count from hitting zero before we're through
*/
inc_io(folio);
if (!bio->bi_iter.bi_size)
goto dump_bio;
submit_bio(bio);
nr_underway++;
bio = NULL;
} else
inc_io(folio);
xlen = (folio_size(folio) - offset) >> inode->i_blkbits;
pblock = metapage_get_blocks(inode, lblock, &xlen);
if (!pblock) {
printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
/*
* We already called inc_io(), but can't cancel it
* with dec_io() until we're done with the page
*/
bad_blocks++;
continue;
}
len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage);
bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_WRITE, GFP_NOFS);
bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9);
bio->bi_end_io = metapage_write_end_io;
bio->bi_private = folio;
/* Don't call bio_add_page yet, we may add to this vec */
bio_offset = offset;
bio_bytes = len << inode->i_blkbits;
xlen -= len;
next_block = lblock + len;
}
if (bio) {
bio_add_folio_nofail(bio, folio, bio_bytes, bio_offset);
if (!bio->bi_iter.bi_size)
goto dump_bio;
submit_bio(bio);
nr_underway++;
}
if (redirty)
folio_redirty_for_writepage(wbc, folio);
folio_unlock(folio);
if (bad_blocks)
goto err_out;
if (nr_underway == 0)
folio_end_writeback(folio);
return 0;
dump_bio:
print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16,
4, bio, sizeof(*bio), 0);
bio_put(bio);
folio_unlock(folio);
dec_io(folio, BLK_STS_OK, last_write_complete);
err_out:
while (bad_blocks--)
dec_io(folio, BLK_STS_OK, last_write_complete);
return -EIO;
}
static int metapage_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct blk_plug plug;
int err;
blk_start_plug(&plug);
err = write_cache_pages(mapping, wbc, metapage_write_folio, NULL);
blk_finish_plug(&plug);
return err;
}
static int metapage_read_folio(struct file *fp, struct folio *folio)
{
struct inode *inode = folio->mapping->host;
struct bio *bio = NULL;
int block_offset;
int blocks_per_page = i_blocks_per_folio(inode, folio);
sector_t page_start; /* address of page in fs blocks */
sector_t pblock;
int xlen;
unsigned int len;
int offset;
BUG_ON(!folio_test_locked(folio));
page_start = folio_pos(folio) >> inode->i_blkbits;
block_offset = 0;
while (block_offset < blocks_per_page) {
xlen = blocks_per_page - block_offset;
pblock = metapage_get_blocks(inode, page_start + block_offset,
&xlen);
if (pblock) {
if (!folio->private)
insert_metapage(folio, NULL);
inc_io(folio);
if (bio)
submit_bio(bio);
bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_READ,
GFP_NOFS);
bio->bi_iter.bi_sector =
pblock << (inode->i_blkbits - 9);
bio->bi_end_io = metapage_read_end_io;
bio->bi_private = folio;
len = xlen << inode->i_blkbits;
offset = block_offset << inode->i_blkbits;
bio_add_folio_nofail(bio, folio, len, offset);
block_offset += xlen;
} else
block_offset++;
}
if (bio)
submit_bio(bio);
else
folio_unlock(folio);
return 0;
}
static bool metapage_release_folio(struct folio *folio, gfp_t gfp_mask)
{
struct metapage *mp;
bool ret = true;
int offset;
for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
mp = folio_to_mp(folio, offset);
if (!mp)
continue;
jfs_info("metapage_release_folio: mp = 0x%p", mp);
if (mp->count || mp->nohomeok ||
test_bit(META_dirty, &mp->flag)) {
jfs_info("count = %ld, nohomeok = %d", mp->count,
mp->nohomeok);
ret = false;
continue;
}
if (mp->lsn)
remove_from_logsync(mp);
remove_metapage(folio, mp);
INCREMENT(mpStat.pagefree);
free_metapage(mp);
}
return ret;
}
static void metapage_invalidate_folio(struct folio *folio, size_t offset,
size_t length)
{
BUG_ON(offset || length < folio_size(folio));
BUG_ON(folio_test_writeback(folio));
metapage_release_folio(folio, 0);
}
const struct address_space_operations jfs_metapage_aops = {
.read_folio = metapage_read_folio,
.writepages = metapage_writepages,
.release_folio = metapage_release_folio,
.invalidate_folio = metapage_invalidate_folio,
.dirty_folio = filemap_dirty_folio,
};
struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
unsigned int size, int absolute,
unsigned long new)
{
int l2BlocksPerPage;
int l2bsize;
struct address_space *mapping;
struct metapage *mp = NULL;
struct folio *folio;
unsigned long page_index;
unsigned long page_offset;
jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
inode->i_ino, lblock, absolute);
l2bsize = inode->i_blkbits;
l2BlocksPerPage = PAGE_SHIFT - l2bsize;
page_index = lblock >> l2BlocksPerPage;
page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
if ((page_offset + size) > PAGE_SIZE) {
jfs_err("MetaData crosses page boundary!!");
jfs_err("lblock = %lx, size = %d", lblock, size);
dump_stack();
return NULL;
}
if (absolute)
mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
else {
/*
* If an nfs client tries to read an inode that is larger
* than any existing inodes, we may try to read past the
* end of the inode map
*/
if ((lblock << inode->i_blkbits) >= inode->i_size)
return NULL;
mapping = inode->i_mapping;
}
if (new && (PSIZE == PAGE_SIZE)) {
folio = filemap_grab_folio(mapping, page_index);
if (IS_ERR(folio)) {
jfs_err("filemap_grab_folio failed!");
return NULL;
}
folio_mark_uptodate(folio);
} else {
folio = read_mapping_folio(mapping, page_index, NULL);
if (IS_ERR(folio)) {
jfs_err("read_mapping_page failed!");
return NULL;
}
folio_lock(folio);
}
mp = folio_to_mp(folio, page_offset);
if (mp) {
if (mp->logical_size != size) {
jfs_error(inode->i_sb,
"get_mp->logical_size != size\n");
jfs_err("logical_size = %d, size = %d",
mp->logical_size, size);
dump_stack();
goto unlock;
}
mp->count++;
lock_metapage(mp);
if (test_bit(META_discard, &mp->flag)) {
if (!new) {
jfs_error(inode->i_sb,
"using a discarded metapage\n");
discard_metapage(mp);
goto unlock;
}
clear_bit(META_discard, &mp->flag);
}
} else {
INCREMENT(mpStat.pagealloc);
mp = alloc_metapage(GFP_NOFS);
if (!mp)
goto unlock;
mp->folio = folio;
mp->sb = inode->i_sb;
mp->flag = 0;
mp->xflag = COMMIT_PAGE;
mp->count = 1;
mp->nohomeok = 0;
mp->logical_size = size;
mp->data = folio_address(folio) + page_offset;
mp->index = lblock;
if (unlikely(insert_metapage(folio, mp))) {
free_metapage(mp);
goto unlock;
}
lock_metapage(mp);
}
if (new) {
jfs_info("zeroing mp = 0x%p", mp);
memset(mp->data, 0, PSIZE);
}
folio_unlock(folio);
jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
return mp;
unlock:
folio_unlock(folio);
return NULL;
}
void grab_metapage(struct metapage * mp)
{
jfs_info("grab_metapage: mp = 0x%p", mp);
folio_get(mp->folio);
folio_lock(mp->folio);
mp->count++;
lock_metapage(mp);
folio_unlock(mp->folio);
}
static int metapage_write_one(struct folio *folio)
{
struct address_space *mapping = folio->mapping;
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
.nr_to_write = folio_nr_pages(folio),
};
int ret = 0;
BUG_ON(!folio_test_locked(folio));
folio_wait_writeback(folio);
if (folio_clear_dirty_for_io(folio)) {
folio_get(folio);
ret = metapage_write_folio(folio, &wbc, NULL);
if (ret == 0)
folio_wait_writeback(folio);
folio_put(folio);
} else {
folio_unlock(folio);
}
if (!ret)
ret = filemap_check_errors(mapping);
return ret;
}
void force_metapage(struct metapage *mp)
{
struct folio *folio = mp->folio;
jfs_info("force_metapage: mp = 0x%p", mp);
set_bit(META_forcewrite, &mp->flag);
clear_bit(META_sync, &mp->flag);
folio_get(folio);
folio_lock(folio);
folio_mark_dirty(folio);
if (metapage_write_one(folio))
jfs_error(mp->sb, "metapage_write_one() failed\n");
clear_bit(META_forcewrite, &mp->flag);
folio_put(folio);
}
void hold_metapage(struct metapage *mp)
{
folio_lock(mp->folio);
}
void put_metapage(struct metapage *mp)
{
if (mp->count || mp->nohomeok) {
/* Someone else will release this */
folio_unlock(mp->folio);
return;
}
folio_get(mp->folio);
mp->count++;
lock_metapage(mp);
folio_unlock(mp->folio);
release_metapage(mp);
}
void release_metapage(struct metapage * mp)
{
struct folio *folio = mp->folio;
jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
folio_lock(folio);
unlock_metapage(mp);
assert(mp->count);
if (--mp->count || mp->nohomeok) {
folio_unlock(folio);
folio_put(folio);
return;
}
if (test_bit(META_dirty, &mp->flag)) {
folio_mark_dirty(folio);
if (test_bit(META_sync, &mp->flag)) {
clear_bit(META_sync, &mp->flag);
if (metapage_write_one(folio))
jfs_error(mp->sb, "metapage_write_one() failed\n");
folio_lock(folio);
}
} else if (mp->lsn) /* discard_metapage doesn't remove it */
remove_from_logsync(mp);
/* Try to keep metapages from using up too much memory */
drop_metapage(folio, mp);
folio_unlock(folio);
folio_put(folio);
}
void __invalidate_metapages(struct inode *ip, s64 addr, int len)
{
sector_t lblock;
int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits;
int BlocksPerPage = 1 << l2BlocksPerPage;
/* All callers are interested in block device's mapping */
struct address_space *mapping =
JFS_SBI(ip->i_sb)->direct_inode->i_mapping;
struct metapage *mp;
unsigned int offset;
/*
* Mark metapages to discard. They will eventually be
* released, but should not be written.
*/
for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len;
lblock += BlocksPerPage) {
struct folio *folio = filemap_lock_folio(mapping,
lblock >> l2BlocksPerPage);
if (IS_ERR(folio))
continue;
for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
mp = folio_to_mp(folio, offset);
if (!mp)
continue;
if (mp->index < addr)
continue;
if (mp->index >= addr + len)
break;
clear_bit(META_dirty, &mp->flag);
set_bit(META_discard, &mp->flag);
if (mp->lsn)
remove_from_logsync(mp);
}
folio_unlock(folio);
folio_put(folio);
}
}
#ifdef CONFIG_JFS_STATISTICS
int jfs_mpstat_proc_show(struct seq_file *m, void *v)
{
seq_printf(m,
"JFS Metapage statistics\n"
"=======================\n"
"page allocations = %d\n"
"page frees = %d\n"
"lock waits = %d\n",
mpStat.pagealloc,
mpStat.pagefree,
mpStat.lockwait);
return 0;
}
#endif
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