| /* |
| * 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_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); |
| |
| #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 |