linux-stable/fs/jfs/jfs_metapage.c
Christoph Hellwig 4246a0b63b block: add a bi_error field to struct bio
Currently we have two different ways to signal an I/O error on a BIO:

 (1) by clearing the BIO_UPTODATE flag
 (2) by returning a Linux errno value to the bi_end_io callback

The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario.  Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.

So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-29 08:55:15 -06:00

837 lines
19 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/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);
}
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);
}
/*
* 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 struct kmem_cache *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, int 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, int 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 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 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,
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 page *page)
{
if (!PageError(page))
SetPageUptodate(page);
unlock_page(page);
}
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);
}
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 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);
}
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_CACHE_SHIFT - inode->i_blkbits);
BUG_ON(!PageLocked(page));
BUG_ON(PageWriteback(page));
set_page_writeback(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);
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(WRITE, bio);
nr_underway++;
bio = NULL;
} else
inc_io(page);
xlen = (PAGE_CACHE_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;
/* 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(WRITE, 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;
}
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_CACHE_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_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_iter.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;
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 int offset,
unsigned int length)
{
BUG_ON(offset || length < PAGE_CACHE_SIZE);
BUG_ON(PageWriteback(page));
metapage_releasepage(page, 0);
}
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_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_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");
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);
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);
/* Try to keep metapages from using up too much memory */
drop_metapage(page, mp);
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
static 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;
}
static int jfs_mpstat_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, jfs_mpstat_proc_show, NULL);
}
const struct file_operations jfs_mpstat_proc_fops = {
.owner = THIS_MODULE,
.open = jfs_mpstat_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#endif