Release 4.10 fs/jfs/jfs_metapage.c

/*
 *   Copyright (C) International Business Machines Corp., 2000-2005
 *   Portions Copyright (C) Christoph Hellwig, 2001-2002
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#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 "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);
}

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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)) {
			unlock_page(mp->page);
			io_schedule();
			lock_page(mp->page);
		}
	} while (trylock_metapage(mp));
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&mp->wait, &wait);
}

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/*
 * Must have mp->page locked
 */


static inline void lock_metapage(struct metapage *mp)
{
	if (trylock_metapage(mp))
		__lock_metapage(mp);
}

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#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;
	
struct metapage *mp[MPS_PER_PAGE];
};

#define mp_anchor(page) ((struct meta_anchor *)page_private(page))



static inline struct metapage *page_to_mp(struct page *page, int offset)
{
	if (!PagePrivate(page))
		return NULL;
	return mp_anchor(page)->mp[offset >> L2PSIZE];
}

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static inline int insert_metapage(struct page *page, struct metapage *mp)
{
	struct meta_anchor *a;
	int index;
	int l2mp_blocks;	/* log2 blocks per metapage */

	if (PagePrivate(page))
		a = mp_anchor(page);
	else {
		a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS);
		if (!a)
			return -ENOMEM;
		set_page_private(page, (unsigned long)a);
		SetPagePrivate(page);
		kmap(page);
	}

	if (mp) {
		l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
		index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
		a->mp_count++;
		a->mp[index] = mp;
	}

	return 0;
}

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static inline void remove_metapage(struct page *page, struct metapage *mp)
{
	struct meta_anchor *a = mp_anchor(page);
	int l2mp_blocks = L2PSIZE - page->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);
		set_page_private(page, 0);
		ClearPagePrivate(page);
		kunmap(page);
	}
}

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static inline void inc_io(struct page *page)
{
	atomic_inc(&mp_anchor(page)->io_count);
}

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static inline void dec_io(struct page *page, void (*handler) (struct page *))
{
	if (atomic_dec_and_test(&mp_anchor(page)->io_count))
		handler(page);
}

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#else


static inline struct metapage *page_to_mp(struct page *page, int offset)
{
	return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL;
}

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dave kleikamp
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static inline int insert_metapage(struct page *page, struct metapage *mp)
{
	if (mp) {
		set_page_private(page, (unsigned long)mp);
		SetPagePrivate(page);
		kmap(page);
	}
	return 0;
}

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dave kleikamp
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static inline void remove_metapage(struct page *page, struct metapage *mp)
{
	set_page_private(page, 0);
	ClearPagePrivate(page);
	kunmap(page);
}

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dave kleikamp
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#define inc_io(page) do {} while(0)

#define dec_io(page, handler) handler(page)

#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;
}

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dave kleikamp
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david rientjes
david rientjes
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static inline void free_metapage(struct metapage *mp)
{
	mempool_free(mp, metapage_mempool);
}

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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;
}

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dave kleikamp
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void metapage_exit(void)
{
	mempool_destroy(metapage_mempool);
	kmem_cache_destroy(metapage_cache);
}

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static inline void drop_metapage(struct page *page, struct metapage *mp)
{
	if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
	    test_bit(META_io, &mp->flag))
		return;
	remove_metapage(page, mp);
	INCREMENT(mpStat.pagefree);
	free_metapage(mp);
}

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/*
 * 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;
}

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static void last_read_complete(struct page *page)
{
	if (!PageError(page))
		SetPageUptodate(page);
	unlock_page(page);
}

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static void metapage_read_end_io(struct bio *bio)
{
	struct page *page = bio->bi_private;

	if (bio->bi_error) {
		printk(KERN_ERR "metapage_read_end_io: I/O error\n");
		SetPageError(page);
	}

	dec_io(page, last_read_complete);
	bio_put(bio);
}

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christoph hellwig
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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);
}

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static void last_write_complete(struct page *page)
{
	struct metapage *mp;
	unsigned int offset;

	for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
		mp = page_to_mp(page, 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
                 */
	}
	end_page_writeback(page);
}

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kirill a. shutemov
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static void metapage_write_end_io(struct bio *bio)
{
	struct page *page = bio->bi_private;

	BUG_ON(!PagePrivate(page));

	if (bio->bi_error) {
		printk(KERN_ERR "metapage_write_end_io: I/O error\n");
		SetPageError(page);
	}
	dec_io(page, last_write_complete);
	bio_put(bio);
}

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dave kleikamp
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christoph hellwig
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neil brown
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static int metapage_writepage(struct page *page, struct writeback_control *wbc)
{
	struct bio *bio = NULL;
	int block_offset;	/* block offset of mp within page */
	struct inode *inode = page->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 = (sector_t)page->index <<
		     (PAGE_SHIFT - inode->i_blkbits);
	BUG_ON(!PageLocked(page));
	BUG_ON(PageWriteback(page));
	set_page_writeback(page);

	for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
		mp = page_to_mp(page, 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 */
			if (bio_add_page(bio, page, bio_bytes, bio_offset) <
			    bio_bytes)
				goto add_failed;
			/*
                         * Increment counter before submitting i/o to keep
                         * count from hitting zero before we're through
                         */
			inc_io(page);
			if (!bio->bi_iter.bi_size)
				goto dump_bio;
			submit_bio(bio);
			nr_underway++;
			bio = NULL;
		} else
			inc_io(page);
		xlen = (PAGE_SIZE - 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(GFP_NOFS, 1);
		bio->bi_bdev = inode->i_sb->s_bdev;
		bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9);
		bio->bi_end_io = metapage_write_end_io;
		bio->bi_private = page;
		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);

		/* 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) {
		if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
				goto add_failed;
		if (!bio->bi_iter.bi_size)
			goto dump_bio;

		submit_bio(bio);
		nr_underway++;
	}
	if (redirty)
		redirty_page_for_writepage(wbc, page);

	unlock_page(page);

	if (bad_blocks)
		goto err_out;

	if (nr_underway == 0)
		end_page_writeback(page);

	return 0;
add_failed:
	/* We should never reach here, since we're only adding one vec */
	printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
	goto skip;
dump_bio:
	print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16,
		       4, bio, sizeof(*bio), 0);
skip:
	bio_put(bio);
	unlock_page(page);
	dec_io(page, last_write_complete);
err_out:
	while (bad_blocks--)
		dec_io(page, last_write_complete);
	return -EIO;
}

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dave kleikamp
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7
63.64%
michael christie
michael christie
9
1.36%
2
18.18%
kent overstreet
kent overstreet
6
0.91%
1
9.09%
kirill a. shutemov
kirill a. shutemov
3
0.45%
1
9.09%
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660
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11
100.00%



static int metapage_readpage(struct file *fp, struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct bio *bio = NULL;
	int block_offset;
	int blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
	sector_t page_start;	/* address of page in fs blocks */
	sector_t pblock;
	int xlen;
	unsigned int len;
	int offset;

	BUG_ON(!PageLocked(page));
	page_start = (sector_t)page->index <<
		     (PAGE_SHIFT - 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 (!PagePrivate(page))
				insert_metapage(page, NULL);
			inc_io(page);
			if (bio)
				submit_bio(bio);

			bio = bio_alloc(GFP_NOFS, 1);
			bio->bi_bdev = inode->i_sb->s_bdev;
			bio->bi_iter.bi_sector =
				pblock << (inode->i_blkbits - 9);
			bio->bi_end_io = metapage_read_end_io;
			bio->bi_private = page;
			bio_set_op_attrs(bio, REQ_OP_READ, 0);
			len = xlen << inode->i_blkbits;
			offset = block_offset << inode->i_blkbits;
			if (bio_add_page(bio, page, len, offset) < len)
				goto add_failed;
			block_offset += xlen;
		} else
			block_offset++;
	}
	if (bio)
		submit_bio(bio);
	else
		unlock_page(page);

	return 0;

add_failed:
	printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
	bio_put(bio);
	dec_io(page, last_read_complete);
	return -EIO;
}

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dave kleikamp
282
95.27%
4
44.44%
michael christie
michael christie
9
3.04%
2
22.22%
kirill a. shutemov
kirill a. shutemov
2
0.68%
1
11.11%
kent overstreet
kent overstreet
2
0.68%
1
11.11%
christoph hellwig
christoph hellwig
1
0.34%
1
11.11%
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9
100.00%



static int metapage_releasepage(struct page *page, gfp_t gfp_mask)
{
	struct metapage *mp;
	int ret = 1;
	int offset;

	for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
		mp = page_to_mp(page, offset);

		if (!mp)
			continue;

		jfs_info("metapage_releasepage: 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 = 0;
			continue;
		}
		if (mp->lsn)
			remove_from_logsync(mp);
		remove_metapage(page, mp);
		INCREMENT(mpStat.pagefree);
		free_metapage(mp);
	}
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
dave kleikamp
dave kleikamp
136
98.55%
5
71.43%
kirill a. shutemov
kirill a. shutemov
1
0.72%
1
14.29%
al viro
al viro
1
0.72%
1
14.29%
Total
138
100.00%
7
100.00%



static void metapage_invalidatepage(struct page *page, unsigned int offset,
				    unsigned int length)
{
	BUG_ON(offset || length < PAGE_SIZE);

	BUG_ON(PageWriteback(page));

	metapage_releasepage(page, 0);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
dave kleikamp
dave kleikamp
28
65.12%
3
50.00%
lukas czerner
lukas czerner
8
18.60%
1
16.67%
neil brown
neil brown
6
13.95%
1
16.67%
kirill a. shutemov
kirill a. shutemov
1
2.33%
1
16.67%
Total
43
100.00%
6
100.00%


const struct address_space_operations jfs_metapage_aops = {
	.readpage	= metapage_readpage,
	.writepage	= metapage_writepage,
	.releasepage	= metapage_releasepage,
	.invalidatepage	= metapage_invalidatepage,
	.set_page_dirty	= __set_page_dirty_nobuffers,
};



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 page *page;
	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)) {
		page = grab_cache_page(mapping, page_index);
		if (!page) {
			jfs_err("grab_cache_page failed!");
			return NULL;
		}
		SetPageUptodate(page);
	} else {
		page = read_mapping_page(mapping, page_index, NULL);
		if (IS_ERR(page) || !PageUptodate(page)) {
			jfs_err("read_mapping_page failed!");
			return NULL;
		}
		lock_page(page);
	}

	mp = page_to_mp(page, page_offset);
	if (mp) {
		if (mp->logical_size != size) {
			jfs_error(inode->i_sb,
				  "get_mp->logical_size != size\n")