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- /*
- * 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
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