linux/fs/jfs/jfs_metapage.c
Dave Kleikamp b964638ffd JFS: Fix multiple errors in metapage_releasepage
It looks like metapage_releasepage was making in invalid assumption that
the releasepage method would not be called on a dirty page.  Instead of
issuing a warning and releasing the metapage, it should return 0, indicating
that the private data for the page cannot be released.

I also realized that metapage_releasepage had the return code all wrong.  If
it is successful in releasing the private data, it should return 1, otherwise
it needs to return 0.

Lastly, there is no need to call wait_on_page_writeback, since
try_to_release_page will not call us with a page in writback state.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
2006-05-24 07:43:38 -05:00

859 lines
20 KiB
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/bio.h>
#include <linux/init.h>
#include <linux/buffer_head.h>
#include <linux/mempool.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(META_locked, &(mp)->flag)
static inline void unlock_metapage(struct metapage *mp)
{
clear_bit(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)) {
unlock_page(mp->page);
schedule();
lock_page(mp->page);
}
} while (trylock_metapage(mp));
__set_current_state(TASK_RUNNING);
remove_wait_queue(&mp->wait, &wait);
}
/*
* Must have mp->page locked
*/
static inline void lock_metapage(struct metapage *mp)
{
if (trylock_metapage(mp))
__lock_metapage(mp);
}
#define METAPOOL_MIN_PAGES 32
static kmem_cache_t *metapage_cache;
static mempool_t *metapage_mempool;
#define MPS_PER_PAGE (PAGE_CACHE_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, uint offset)
{
if (!PagePrivate(page))
return NULL;
return mp_anchor(page)->mp[offset >> L2PSIZE];
}
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;
}
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);
}
}
static inline void inc_io(struct page *page)
{
atomic_inc(&mp_anchor(page)->io_count);
}
static inline void dec_io(struct page *page, void (*handler) (struct page *))
{
if (atomic_dec_and_test(&mp_anchor(page)->io_count))
handler(page);
}
#else
static inline struct metapage *page_to_mp(struct page *page, uint offset)
{
return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL;
}
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;
}
static inline void remove_metapage(struct page *page, struct metapage *mp)
{
set_page_private(page, 0);
ClearPagePrivate(page);
kunmap(page);
}
#define inc_io(page) do {} while(0)
#define dec_io(page, handler) handler(page)
#endif
static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
{
struct metapage *mp = (struct metapage *)foo;
if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
SLAB_CTOR_CONSTRUCTOR) {
mp->lid = 0;
mp->lsn = 0;
mp->flag = 0;
mp->data = NULL;
mp->clsn = 0;
mp->log = NULL;
set_bit(META_free, &mp->flag);
init_waitqueue_head(&mp->wait);
}
}
static inline struct metapage *alloc_metapage(gfp_t gfp_mask)
{
return mempool_alloc(metapage_mempool, gfp_mask);
}
static inline void free_metapage(struct metapage *mp)
{
mp->flag = 0;
set_bit(META_free, &mp->flag);
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, init_once, 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 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);
}
/*
* Metapage address space operations
*/
static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
unsigned int *len)
{
int rc = 0;
int xflag;
s64 xaddr;
sector_t file_blocks = (inode->i_size + inode->i_blksize - 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 page *page)
{
if (!PageError(page))
SetPageUptodate(page);
unlock_page(page);
}
static int metapage_read_end_io(struct bio *bio, unsigned int bytes_done,
int err)
{
struct page *page = bio->bi_private;
if (bio->bi_size)
return 1;
if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
printk(KERN_ERR "metapage_read_end_io: I/O error\n");
SetPageError(page);
}
dec_io(page, last_read_complete);
bio_put(bio);
return 0;
}
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 page *page)
{
struct metapage *mp;
unsigned int offset;
for (offset = 0; offset < PAGE_CACHE_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);
}
static int metapage_write_end_io(struct bio *bio, unsigned int bytes_done,
int err)
{
struct page *page = bio->bi_private;
BUG_ON(!PagePrivate(page));
if (bio->bi_size)
return 1;
if (! test_bit(BIO_UPTODATE, &bio->bi_flags)) {
printk(KERN_ERR "metapage_write_end_io: I/O error\n");
SetPageError(page);
}
dec_io(page, last_write_complete);
bio_put(bio);
return 0;
}
static int metapage_writepage(struct page *page, struct writeback_control *wbc)
{
struct bio *bio = NULL;
unsigned int block_offset; /* block offset of mp within page */
struct inode *inode = page->mapping->host;
unsigned int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
unsigned int len;
unsigned int xlen;
struct metapage *mp;
int redirty = 0;
sector_t lblock;
sector_t pblock;
sector_t next_block = 0;
sector_t page_start;
unsigned long bio_bytes = 0;
unsigned long bio_offset = 0;
unsigned int offset;
page_start = (sector_t)page->index <<
(PAGE_CACHE_SHIFT - inode->i_blkbits);
BUG_ON(!PageLocked(page));
BUG_ON(PageWriteback(page));
for (offset = 0; offset < PAGE_CACHE_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);
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;
set_bit(META_io, &mp->flag);
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_size)
goto dump_bio;
submit_bio(WRITE, bio);
bio = NULL;
} else {
set_page_writeback(page);
inc_io(page);
}
xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits;
pblock = metapage_get_blocks(inode, lblock, &xlen);
if (!pblock) {
/* Need better error handling */
printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
dec_io(page, last_write_complete);
continue;
}
set_bit(META_io, &mp->flag);
len = min(xlen, (uint) JFS_SBI(inode->i_sb)->nbperpage);
bio = bio_alloc(GFP_NOFS, 1);
bio->bi_bdev = inode->i_sb->s_bdev;
bio->bi_sector = pblock << (inode->i_blkbits - 9);
bio->bi_end_io = metapage_write_end_io;
bio->bi_private = page;
/* 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_size)
goto dump_bio;
submit_bio(WRITE, bio);
}
if (redirty)
redirty_page_for_writepage(wbc, page);
unlock_page(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:
dump_mem("bio", bio, sizeof(*bio));
skip:
bio_put(bio);
unlock_page(page);
dec_io(page, last_write_complete);
return -EIO;
}
static int metapage_readpage(struct file *fp, struct page *page)
{
struct inode *inode = page->mapping->host;
struct bio *bio = NULL;
unsigned int block_offset;
unsigned int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits;
sector_t page_start; /* address of page in fs blocks */
sector_t pblock;
unsigned int xlen;
unsigned int len;
unsigned int offset;
BUG_ON(!PageLocked(page));
page_start = (sector_t)page->index <<
(PAGE_CACHE_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(READ, bio);
bio = bio_alloc(GFP_NOFS, 1);
bio->bi_bdev = inode->i_sb->s_bdev;
bio->bi_sector = pblock << (inode->i_blkbits - 9);
bio->bi_end_io = metapage_read_end_io;
bio->bi_private = page;
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(READ, 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;
}
static int metapage_releasepage(struct page *page, gfp_t gfp_mask)
{
struct metapage *mp;
int ret = 1;
unsigned int offset;
for (offset = 0; offset < PAGE_CACHE_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;
}
static void metapage_invalidatepage(struct page *page, unsigned long offset)
{
BUG_ON(offset);
BUG_ON(PageWriteback(page));
metapage_releasepage(page, 0);
}
struct address_space_operations jfs_metapage_aops = {
.readpage = metapage_readpage,
.writepage = metapage_writepage,
.sync_page = block_sync_page,
.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_CACHE_SHIFT - l2bsize;
page_index = lblock >> l2BlocksPerPage;
page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
if ((page_offset + size) > PAGE_CACHE_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_CACHE_SIZE)) {
page = grab_cache_page(mapping, page_index);
if (!page) {
jfs_err("grab_cache_page failed!");
return NULL;
}
SetPageUptodate(page);
} else {
page = read_cache_page(mapping, page_index,
(filler_t *)mapping->a_ops->readpage, NULL);
if (IS_ERR(page) || !PageUptodate(page)) {
jfs_err("read_cache_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_metapage: mp->logical_size != size");
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,
"__get_metapage: using a "
"discarded metapage");
discard_metapage(mp);
goto unlock;
}
clear_bit(META_discard, &mp->flag);
}
} else {
INCREMENT(mpStat.pagealloc);
mp = alloc_metapage(GFP_NOFS);
mp->page = page;
mp->flag = 0;
mp->xflag = COMMIT_PAGE;
mp->count = 1;
mp->nohomeok = 0;
mp->logical_size = size;
mp->data = page_address(page) + page_offset;
mp->index = lblock;
if (unlikely(insert_metapage(page, mp))) {
free_metapage(mp);
goto unlock;
}
lock_metapage(mp);
}
if (new) {
jfs_info("zeroing mp = 0x%p", mp);
memset(mp->data, 0, PSIZE);
}
unlock_page(page);
jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
return mp;
unlock:
unlock_page(page);
return NULL;
}
void grab_metapage(struct metapage * mp)
{
jfs_info("grab_metapage: mp = 0x%p", mp);
page_cache_get(mp->page);
lock_page(mp->page);
mp->count++;
lock_metapage(mp);
unlock_page(mp->page);
}
void force_metapage(struct metapage *mp)
{
struct page *page = mp->page;
jfs_info("force_metapage: mp = 0x%p", mp);
set_bit(META_forcewrite, &mp->flag);
clear_bit(META_sync, &mp->flag);
page_cache_get(page);
lock_page(page);
set_page_dirty(page);
write_one_page(page, 1);
clear_bit(META_forcewrite, &mp->flag);
page_cache_release(page);
}
void hold_metapage(struct metapage *mp)
{
lock_page(mp->page);
}
void put_metapage(struct metapage *mp)
{
if (mp->count || mp->nohomeok) {
/* Someone else will release this */
unlock_page(mp->page);
return;
}
page_cache_get(mp->page);
mp->count++;
lock_metapage(mp);
unlock_page(mp->page);
release_metapage(mp);
}
void release_metapage(struct metapage * mp)
{
struct page *page = mp->page;
jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
BUG_ON(!page);
lock_page(page);
unlock_metapage(mp);
assert(mp->count);
if (--mp->count || mp->nohomeok) {
unlock_page(page);
page_cache_release(page);
return;
}
if (test_bit(META_dirty, &mp->flag)) {
set_page_dirty(page);
if (test_bit(META_sync, &mp->flag)) {
clear_bit(META_sync, &mp->flag);
write_one_page(page, 1);
lock_page(page); /* write_one_page unlocks the page */
}
} else if (mp->lsn) /* discard_metapage doesn't remove it */
remove_from_logsync(mp);
#if MPS_PER_PAGE == 1
/*
* If we know this is the only thing in the page, we can throw
* the page out of the page cache. If pages are larger, we
* don't want to do this.
*/
/* Retest mp->count since we may have released page lock */
if (test_bit(META_discard, &mp->flag) && !mp->count) {
clear_page_dirty(page);
ClearPageUptodate(page);
}
#else
/* Try to keep metapages from using up too much memory */
drop_metapage(page, mp);
#endif
unlock_page(page);
page_cache_release(page);
}
void __invalidate_metapages(struct inode *ip, s64 addr, int len)
{
sector_t lblock;
int l2BlocksPerPage = PAGE_CACHE_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;
struct page *page;
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) {
page = find_lock_page(mapping, lblock >> l2BlocksPerPage);
if (!page)
continue;
for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
mp = page_to_mp(page, 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);
}
unlock_page(page);
page_cache_release(page);
}
}
#ifdef CONFIG_JFS_STATISTICS
int jfs_mpstat_read(char *buffer, char **start, off_t offset, int length,
int *eof, void *data)
{
int len = 0;
off_t begin;
len += sprintf(buffer,
"JFS Metapage statistics\n"
"=======================\n"
"page allocations = %d\n"
"page frees = %d\n"
"lock waits = %d\n",
mpStat.pagealloc,
mpStat.pagefree,
mpStat.lockwait);
begin = offset;
*start = buffer + begin;
len -= begin;
if (len > length)
len = length;
else
*eof = 1;
if (len < 0)
len = 0;
return len;
}
#endif