/* * 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 void init_once(void *foo) { struct metapage *mp = (struct metapage *)foo; 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); 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, int err) { struct page *page = bio->bi_private; 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); } 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, int err) { struct page *page = bio->bi_private; BUG_ON(!PagePrivate(page)); 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); } 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_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_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); 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_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 long offset) { BUG_ON(offset); BUG_ON(PageWriteback(page)); metapage_releasepage(page, 0); } const 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_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_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); /* 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