X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fbuffer.c;h=7f6d65925dea9ba1851e605f9e3b96dff1cc8109;hb=4e76c8a9fa413ccc09d3f7f664183dcce3555d57;hp=3c40d6382925b12a01f88c60a4ecafda4d2146dc;hpb=6a77f38946aaee1cd85eeec6cf4229b204c15071;p=linux-2.6.git diff --git a/fs/buffer.c b/fs/buffer.c index 3c40d6382..7f6d65925 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -39,6 +40,8 @@ #include #include #include +#include +#include static int fsync_buffers_list(spinlock_t *lock, struct list_head *list); static void invalidate_bh_lrus(void); @@ -94,7 +97,7 @@ static void __clear_page_buffers(struct page *page) { ClearPagePrivate(page); - page->private = 0; + set_page_private(page, 0); page_cache_release(page); } @@ -151,24 +154,13 @@ int sync_blockdev(struct block_device *bdev) { int ret = 0; - if (bdev) { - int err; - - ret = filemap_fdatawrite(bdev->bd_inode->i_mapping); - err = filemap_fdatawait(bdev->bd_inode->i_mapping); - if (!ret) - ret = err; - } + if (bdev) + ret = filemap_write_and_wait(bdev->bd_inode->i_mapping); return ret; } EXPORT_SYMBOL(sync_blockdev); -/* - * Write out and wait upon all dirty data associated with this - * superblock. Filesystem data as well as the underlying block - * device. Takes the superblock lock. - */ -int fsync_super(struct super_block *sb) +static void __fsync_super(struct super_block *sb) { sync_inodes_sb(sb, 0); DQUOT_SYNC(sb); @@ -180,7 +172,16 @@ int fsync_super(struct super_block *sb) sb->s_op->sync_fs(sb, 1); sync_blockdev(sb->s_bdev); sync_inodes_sb(sb, 1); +} +/* + * Write out and wait upon all dirty data associated with this + * superblock. Filesystem data as well as the underlying block + * device. Takes the superblock lock. + */ +int fsync_super(struct super_block *sb) +{ + __fsync_super(sb); return sync_blockdev(sb->s_bdev); } @@ -204,7 +205,7 @@ int fsync_bdev(struct block_device *bdev) * freeze_bdev -- lock a filesystem and force it into a consistent state * @bdev: blockdevice to lock * - * This takes the block device bd_mount_sem to make sure no new mounts + * This takes the block device bd_mount_mutex to make sure no new mounts * happen on bdev until thaw_bdev() is called. * If a superblock is found on this device, we take the s_umount semaphore * on it to make sure nobody unmounts until the snapshot creation is done. @@ -213,28 +214,16 @@ struct super_block *freeze_bdev(struct block_device *bdev) { struct super_block *sb; - down(&bdev->bd_mount_sem); + mutex_lock(&bdev->bd_mount_mutex); sb = get_super(bdev); if (sb && !(sb->s_flags & MS_RDONLY)) { sb->s_frozen = SB_FREEZE_WRITE; - wmb(); - - sync_inodes_sb(sb, 0); - DQUOT_SYNC(sb); - - lock_super(sb); - if (sb->s_dirt && sb->s_op->write_super) - sb->s_op->write_super(sb); - unlock_super(sb); + smp_wmb(); - if (sb->s_op->sync_fs) - sb->s_op->sync_fs(sb, 1); - - sync_blockdev(sb->s_bdev); - sync_inodes_sb(sb, 1); + __fsync_super(sb); sb->s_frozen = SB_FREEZE_TRANS; - wmb(); + smp_wmb(); sync_blockdev(sb->s_bdev); @@ -262,12 +251,12 @@ void thaw_bdev(struct block_device *bdev, struct super_block *sb) if (sb->s_op->unlockfs) sb->s_op->unlockfs(sb); sb->s_frozen = SB_UNFROZEN; - wmb(); + smp_wmb(); wake_up(&sb->s_wait_unfrozen); drop_super(sb); } - up(&bdev->bd_mount_sem); + mutex_unlock(&bdev->bd_mount_mutex); } EXPORT_SYMBOL(thaw_bdev); @@ -277,7 +266,7 @@ EXPORT_SYMBOL(thaw_bdev); */ static void do_sync(unsigned long wait) { - wakeup_bdflush(0); + wakeup_pdflush(0); sync_inodes(0); /* All mappings, inodes and their blockdevs */ DQUOT_SYNC(NULL); sync_supers(); /* Write the superblocks */ @@ -330,81 +319,59 @@ int file_fsync(struct file *filp, struct dentry *dentry, int datasync) return ret; } -asmlinkage long sys_fsync(unsigned int fd) +long do_fsync(struct file *file, int datasync) { - struct file * file; - struct address_space *mapping; - int ret, err; - - ret = -EBADF; - file = fget(fd); - if (!file) - goto out; - - mapping = file->f_mapping; + int ret; + int err; + struct address_space *mapping = file->f_mapping; - ret = -EINVAL; if (!file->f_op || !file->f_op->fsync) { /* Why? We can still call filemap_fdatawrite */ - goto out_putf; + ret = -EINVAL; + goto out; } current->flags |= PF_SYNCWRITE; ret = filemap_fdatawrite(mapping); /* - * We need to protect against concurrent writers, - * which could cause livelocks in fsync_buffers_list + * We need to protect against concurrent writers, which could cause + * livelocks in fsync_buffers_list(). */ - down(&mapping->host->i_sem); - err = file->f_op->fsync(file, file->f_dentry, 0); + mutex_lock(&mapping->host->i_mutex); + err = file->f_op->fsync(file, file->f_dentry, datasync); if (!ret) ret = err; - up(&mapping->host->i_sem); + mutex_unlock(&mapping->host->i_mutex); err = filemap_fdatawait(mapping); if (!ret) ret = err; current->flags &= ~PF_SYNCWRITE; - -out_putf: - fput(file); out: return ret; } -asmlinkage long sys_fdatasync(unsigned int fd) +static long __do_fsync(unsigned int fd, int datasync) { - struct file * file; - struct address_space *mapping; - int ret, err; + struct file *file; + int ret = -EBADF; - ret = -EBADF; file = fget(fd); - if (!file) - goto out; - - ret = -EINVAL; - if (!file->f_op || !file->f_op->fsync) - goto out_putf; - - mapping = file->f_mapping; + if (file) { + ret = do_fsync(file, datasync); + fput(file); + } + return ret; +} - current->flags |= PF_SYNCWRITE; - ret = filemap_fdatawrite(mapping); - down(&mapping->host->i_sem); - err = file->f_op->fsync(file, file->f_dentry, 1); - if (!ret) - ret = err; - up(&mapping->host->i_sem); - err = filemap_fdatawait(mapping); - if (!ret) - ret = err; - current->flags &= ~PF_SYNCWRITE; +asmlinkage long sys_fsync(unsigned int fd) +{ + return __do_fsync(fd, 0); +} -out_putf: - fput(file); -out: - return ret; +asmlinkage long sys_fdatasync(unsigned int fd) +{ + return __do_fsync(fd, 1); } /* @@ -419,7 +386,7 @@ out: * private_lock is contended then so is mapping->tree_lock). */ static struct buffer_head * -__find_get_block_slow(struct block_device *bdev, sector_t block, int unused) +__find_get_block_slow(struct block_device *bdev, sector_t block) { struct inode *bd_inode = bdev->bd_inode; struct address_space *bd_mapping = bd_inode->i_mapping; @@ -459,8 +426,10 @@ __find_get_block_slow(struct block_device *bdev, sector_t block, int unused) if (all_mapped) { printk("__find_get_block_slow() failed. " "block=%llu, b_blocknr=%llu\n", - (unsigned long long)block, (unsigned long long)bh->b_blocknr); - printk("b_state=0x%08lx, b_size=%u\n", bh->b_state, bh->b_size); + (unsigned long long)block, + (unsigned long long)bh->b_blocknr); + printk("b_state=0x%08lx, b_size=%zu\n", + bh->b_state, bh->b_size); printk("device blocksize: %d\n", 1 << bd_inode->i_blkbits); } out_unlock: @@ -504,13 +473,18 @@ out: pass does the actual I/O. */ void invalidate_bdev(struct block_device *bdev, int destroy_dirty_buffers) { + struct address_space *mapping = bdev->bd_inode->i_mapping; + + if (mapping->nrpages == 0) + return; + invalidate_bh_lrus(); /* * FIXME: what about destroy_dirty_buffers? * We really want to use invalidate_inode_pages2() for * that, but not until that's cleaned up. */ - invalidate_inode_pages(bdev->bd_inode->i_mapping); + invalidate_inode_pages(mapping); } /* @@ -521,13 +495,13 @@ static void free_more_memory(void) struct zone **zones; pg_data_t *pgdat; - wakeup_bdflush(1024); + wakeup_pdflush(1024); yield(); - for_each_pgdat(pgdat) { - zones = pgdat->node_zonelists[GFP_NOFS&GFP_ZONEMASK].zones; + for_each_online_pgdat(pgdat) { + zones = pgdat->node_zonelists[gfp_zone(GFP_NOFS)].zones; if (*zones) - try_to_free_pages(zones, GFP_NOFS, 0); + try_to_free_pages(zones, GFP_NOFS); } } @@ -537,8 +511,8 @@ static void free_more_memory(void) */ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) { - static DEFINE_SPINLOCK(page_uptodate_lock); unsigned long flags; + struct buffer_head *first; struct buffer_head *tmp; struct page *page; int page_uptodate = 1; @@ -560,7 +534,9 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) * two buffer heads end IO at almost the same time and both * decide that the page is now completely done. */ - spin_lock_irqsave(&page_uptodate_lock, flags); + first = page_buffers(page); + local_irq_save(flags); + bit_spin_lock(BH_Uptodate_Lock, &first->b_state); clear_buffer_async_read(bh); unlock_buffer(bh); tmp = bh; @@ -573,7 +549,8 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) } tmp = tmp->b_this_page; } while (tmp != bh); - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); /* * If none of the buffers had errors and they are all @@ -585,7 +562,8 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) return; still_busy: - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); return; } @@ -596,8 +574,8 @@ still_busy: void end_buffer_async_write(struct buffer_head *bh, int uptodate) { char b[BDEVNAME_SIZE]; - static DEFINE_SPINLOCK(page_uptodate_lock); unsigned long flags; + struct buffer_head *first; struct buffer_head *tmp; struct page *page; @@ -618,7 +596,10 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate) SetPageError(page); } - spin_lock_irqsave(&page_uptodate_lock, flags); + first = page_buffers(page); + local_irq_save(flags); + bit_spin_lock(BH_Uptodate_Lock, &first->b_state); + clear_buffer_async_write(bh); unlock_buffer(bh); tmp = bh->b_this_page; @@ -629,12 +610,14 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate) } tmp = tmp->b_this_page; } - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); end_page_writeback(page); return; still_busy: - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); return; } @@ -773,15 +756,14 @@ repeat: /** * sync_mapping_buffers - write out and wait upon a mapping's "associated" * buffers - * @buffer_mapping - the mapping which backs the buffers' data - * @mapping - the mapping which wants those buffers written + * @mapping: the mapping which wants those buffers written * * Starts I/O against the buffers at mapping->private_list, and waits upon * that I/O. * - * Basically, this is a convenience function for fsync(). @buffer_mapping is - * the blockdev which "owns" the buffers and @mapping is a file or directory - * which needs those buffers to be written for a successful fsync(). + * Basically, this is a convenience function for fsync(). + * @mapping is a file or directory which needs those buffers to be written for + * a successful fsync(). */ int sync_mapping_buffers(struct address_space *mapping) { @@ -821,8 +803,7 @@ void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode) if (!mapping->assoc_mapping) { mapping->assoc_mapping = buffer_mapping; } else { - if (mapping->assoc_mapping != buffer_mapping) - BUG(); + BUG_ON(mapping->assoc_mapping != buffer_mapping); } if (list_empty(&bh->b_assoc_buffers)) { spin_lock(&buffer_mapping->private_lock); @@ -875,18 +856,18 @@ int __set_page_dirty_buffers(struct page *page) spin_unlock(&mapping->private_lock); if (!TestSetPageDirty(page)) { - spin_lock_irq(&mapping->tree_lock); + write_lock_irq(&mapping->tree_lock); if (page->mapping) { /* Race with truncate? */ - if (!mapping->backing_dev_info->memory_backed) + if (mapping_cap_account_dirty(mapping)) inc_page_state(nr_dirty); radix_tree_tag_set(&mapping->page_tree, page_index(page), PAGECACHE_TAG_DIRTY); } - spin_unlock_irq(&mapping->tree_lock); + write_unlock_irq(&mapping->tree_lock); __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); + return 1; } - return 0; } EXPORT_SYMBOL(__set_page_dirty_buffers); @@ -933,8 +914,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list) * contents - it is a noop if I/O is still in * flight on potentially older contents. */ - wait_on_buffer(bh); - ll_rw_block(WRITE, 1, &bh); + ll_rw_block(SWRITE, 1, &bh); brelse(bh); spin_lock(lock); } @@ -1043,12 +1023,13 @@ try_again: bh->b_state = 0; atomic_set(&bh->b_count, 0); + bh->b_private = NULL; bh->b_size = size; /* Link the buffer to its page */ set_bh_page(bh, page, offset); - bh->b_end_io = NULL; + init_buffer(bh, NULL, NULL); } return head; /* @@ -1139,8 +1120,7 @@ grow_dev_page(struct block_device *bdev, sector_t block, if (!page) return NULL; - if (!PageLocked(page)) - BUG(); + BUG_ON(!PageLocked(page)); if (page_has_buffers(page)) { bh = page_buffers(page); @@ -1186,7 +1166,7 @@ failed: * some of those buffers may be aliases of filesystem data. * grow_dev_page() will go BUG() if this happens. */ -static inline int +static int grow_buffers(struct block_device *bdev, sector_t block, int size) { struct page *page; @@ -1210,7 +1190,7 @@ grow_buffers(struct block_device *bdev, sector_t block, int size) return 1; } -struct buffer_head * +static struct buffer_head * __getblk_slow(struct block_device *bdev, sector_t block, int size) { /* Size must be multiple of hard sectorsize */ @@ -1262,6 +1242,7 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size) /** * mark_buffer_dirty - mark a buffer_head as needing writeout + * @bh: the buffer_head to mark dirty * * mark_buffer_dirty() will set the dirty bit against the buffer, then set its * backing page dirty, then tag the page as dirty in its address_space's radix @@ -1411,7 +1392,7 @@ static void bh_lru_install(struct buffer_head *bh) /* * Look up the bh in this cpu's LRU. If it's there, move it to the head. */ -static inline struct buffer_head * +static struct buffer_head * lookup_bh_lru(struct block_device *bdev, sector_t block, int size) { struct buffer_head *ret = NULL; @@ -1453,7 +1434,7 @@ __find_get_block(struct block_device *bdev, sector_t block, int size) struct buffer_head *bh = lookup_bh_lru(bdev, block, size); if (bh == NULL) { - bh = __find_get_block_slow(bdev, block, size); + bh = __find_get_block_slow(bdev, block); if (bh) bh_lru_install(bh); } @@ -1493,13 +1474,16 @@ EXPORT_SYMBOL(__getblk); void __breadahead(struct block_device *bdev, sector_t block, int size) { struct buffer_head *bh = __getblk(bdev, block, size); - ll_rw_block(READA, 1, &bh); - brelse(bh); + if (likely(bh)) { + ll_rw_block(READA, 1, &bh); + brelse(bh); + } } EXPORT_SYMBOL(__breadahead); /** * __bread() - reads a specified block and returns the bh + * @bdev: the block_device to read from * @block: number of block * @size: size (in bytes) to read * @@ -1511,7 +1495,7 @@ __bread(struct block_device *bdev, sector_t block, int size) { struct buffer_head *bh = __getblk(bdev, block, size); - if (!buffer_uptodate(bh)) + if (likely(bh) && !buffer_uptodate(bh)) bh = __bread_slow(bh); return bh; } @@ -1543,8 +1527,7 @@ void set_bh_page(struct buffer_head *bh, struct page *page, unsigned long offset) { bh->b_page = page; - if (offset >= PAGE_SIZE) - BUG(); + BUG_ON(offset >= PAGE_SIZE); if (PageHighMem(page)) /* * This catches illegal uses and preserves the offset: @@ -1558,7 +1541,7 @@ EXPORT_SYMBOL(set_bh_page); /* * Called when truncating a buffer on a page completely. */ -static inline void discard_buffer(struct buffer_head * bh) +static void discard_buffer(struct buffer_head * bh) { lock_buffer(bh); clear_buffer_dirty(bh); @@ -1585,7 +1568,7 @@ static inline void discard_buffer(struct buffer_head * bh) * * NOTE: @gfp_mask may go away, and this function may become non-blocking. */ -int try_to_release_page(struct page *page, int gfp_mask) +int try_to_release_page(struct page *page, gfp_t gfp_mask) { struct address_space * const mapping = page->mapping; @@ -1614,11 +1597,10 @@ EXPORT_SYMBOL(try_to_release_page); * point. Because the caller is about to free (and possibly reuse) those * blocks on-disk. */ -int block_invalidatepage(struct page *page, unsigned long offset) +void block_invalidatepage(struct page *page, unsigned long offset) { struct buffer_head *head, *bh, *next; unsigned int curr_off = 0; - int ret = 1; BUG_ON(!PageLocked(page)); if (!page_has_buffers(page)) @@ -1645,12 +1627,20 @@ int block_invalidatepage(struct page *page, unsigned long offset) * so real IO is not possible anymore. */ if (offset == 0) - ret = try_to_release_page(page, 0); + try_to_release_page(page, 0); out: - return ret; + return; } EXPORT_SYMBOL(block_invalidatepage); +void do_invalidatepage(struct page *page, unsigned long offset) +{ + void (*invalidatepage)(struct page *, unsigned long); + invalidatepage = page->mapping->a_ops->invalidatepage ? : + block_invalidatepage; + (*invalidatepage)(page, offset); +} + /* * We attach and possibly dirty the buffers atomically wrt * __set_page_dirty_buffers() via private_lock. try_to_free_buffers @@ -1708,7 +1698,7 @@ void unmap_underlying_metadata(struct block_device *bdev, sector_t block) might_sleep(); - old_bh = __find_get_block_slow(bdev, block, 0); + old_bh = __find_get_block_slow(bdev, block); if (old_bh) { clear_buffer_dirty(old_bh); wait_on_buffer(old_bh); @@ -1750,6 +1740,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page, sector_t block; sector_t last_block; struct buffer_head *bh, *head; + const unsigned blocksize = 1 << inode->i_blkbits; int nr_underway = 0; BUG_ON(!PageLocked(page)); @@ -1757,7 +1748,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page, last_block = (i_size_read(inode) - 1) >> inode->i_blkbits; if (!page_has_buffers(page)) { - create_empty_buffers(page, 1 << inode->i_blkbits, + create_empty_buffers(page, blocksize, (1 << BH_Dirty)|(1 << BH_Uptodate)); } @@ -1771,7 +1762,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page, * handle that here by just cleaning them. */ - block = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); + block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); head = page_buffers(page); bh = head; @@ -1792,6 +1783,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page, clear_buffer_dirty(bh); set_buffer_uptodate(bh); } else if (!buffer_mapped(bh) && buffer_dirty(bh)) { + WARN_ON(bh->b_size != blocksize); err = get_block(inode, block, bh, 1); if (err) goto recover; @@ -1807,7 +1799,6 @@ static int __block_write_full_page(struct inode *inode, struct page *page, } while (bh != head); do { - get_bh(bh); if (!buffer_mapped(bh)) continue; /* @@ -1836,7 +1827,6 @@ static int __block_write_full_page(struct inode *inode, struct page *page, */ BUG_ON(PageWriteback(page)); set_page_writeback(page); - unlock_page(page); do { struct buffer_head *next = bh->b_this_page; @@ -1844,9 +1834,9 @@ static int __block_write_full_page(struct inode *inode, struct page *page, submit_bh(WRITE, bh); nr_underway++; } - put_bh(bh); bh = next; } while (bh != head); + unlock_page(page); err = 0; done: @@ -1885,7 +1875,6 @@ recover: bh = head; /* Recovery: lock and submit the mapped buffers */ do { - get_bh(bh); if (buffer_mapped(bh) && buffer_dirty(bh)) { lock_buffer(bh); mark_buffer_async_write(bh); @@ -1908,7 +1897,6 @@ recover: submit_bh(WRITE, bh); nr_underway++; } - put_bh(bh); bh = next; } while (bh != head); goto done; @@ -1949,11 +1937,11 @@ static int __block_prepare_write(struct inode *inode, struct page *page, if (buffer_new(bh)) clear_buffer_new(bh); if (!buffer_mapped(bh)) { + WARN_ON(bh->b_size != blocksize); err = get_block(inode, block, bh, 1); if (err) - goto out; + break; if (buffer_new(bh)) { - clear_buffer_new(bh); unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); if (PageUptodate(page)) { @@ -1993,10 +1981,17 @@ static int __block_prepare_write(struct inode *inode, struct page *page, while(wait_bh > wait) { wait_on_buffer(*--wait_bh); if (!buffer_uptodate(*wait_bh)) - return -EIO; + err = -EIO; } - return 0; -out: + if (!err) { + bh = head; + do { + if (buffer_new(bh)) + clear_buffer_new(bh); + } while ((bh = bh->b_this_page) != head); + return 0; + } + /* Error case: */ /* * Zero out any newly allocated blocks to avoid exposing stale * data. If BH_New is set, we know that the block was newly @@ -2077,8 +2072,7 @@ int block_read_full_page(struct page *page, get_block_t *get_block) int nr, i; int fully_mapped = 1; - if (!PageLocked(page)) - PAGE_BUG(page); + BUG_ON(!PageLocked(page)); blocksize = 1 << inode->i_blkbits; if (!page_has_buffers(page)) create_empty_buffers(page, blocksize, 0); @@ -2095,9 +2089,13 @@ int block_read_full_page(struct page *page, get_block_t *get_block) continue; if (!buffer_mapped(bh)) { + int err = 0; + fully_mapped = 0; if (iblock < lblock) { - if (get_block(inode, iblock, bh, 0)) + WARN_ON(bh->b_size != blocksize); + err = get_block(inode, iblock, bh, 0); + if (err) SetPageError(page); } if (!buffer_mapped(bh)) { @@ -2105,7 +2103,8 @@ int block_read_full_page(struct page *page, get_block_t *get_block) memset(kaddr + i * blocksize, 0, blocksize); flush_dcache_page(page); kunmap_atomic(kaddr, KM_USER0); - set_buffer_uptodate(bh); + if (!err) + set_buffer_uptodate(bh); continue; } /* @@ -2158,11 +2157,12 @@ int block_read_full_page(struct page *page, get_block_t *get_block) * truncates. Uses prepare/commit_write to allow the filesystem to * deal with the hole. */ -int generic_cont_expand(struct inode *inode, loff_t size) +static int __generic_cont_expand(struct inode *inode, loff_t size, + pgoff_t index, unsigned int offset) { struct address_space *mapping = inode->i_mapping; struct page *page; - unsigned long index, offset, limit; + unsigned long limit; int err; err = -EFBIG; @@ -2174,24 +2174,24 @@ int generic_cont_expand(struct inode *inode, loff_t size) if (size > inode->i_sb->s_maxbytes) goto out; - offset = (size & (PAGE_CACHE_SIZE-1)); /* Within page */ - - /* ugh. in prepare/commit_write, if from==to==start of block, we - ** skip the prepare. make sure we never send an offset for the start - ** of a block - */ - if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) { - offset++; - } - index = size >> PAGE_CACHE_SHIFT; err = -ENOMEM; page = grab_cache_page(mapping, index); if (!page) goto out; err = mapping->a_ops->prepare_write(NULL, page, offset, offset); - if (!err) { - err = mapping->a_ops->commit_write(NULL, page, offset, offset); + if (err) { + /* + * ->prepare_write() may have instantiated a few blocks + * outside i_size. Trim these off again. + */ + unlock_page(page); + page_cache_release(page); + vmtruncate(inode, inode->i_size); + goto out; } + + err = mapping->a_ops->commit_write(NULL, page, offset, offset); + unlock_page(page); page_cache_release(page); if (err > 0) @@ -2200,6 +2200,36 @@ out: return err; } +int generic_cont_expand(struct inode *inode, loff_t size) +{ + pgoff_t index; + unsigned int offset; + + offset = (size & (PAGE_CACHE_SIZE - 1)); /* Within page */ + + /* ugh. in prepare/commit_write, if from==to==start of block, we + ** skip the prepare. make sure we never send an offset for the start + ** of a block + */ + if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) { + /* caller must handle this extra byte. */ + offset++; + } + index = size >> PAGE_CACHE_SHIFT; + + return __generic_cont_expand(inode, size, index, offset); +} + +int generic_cont_expand_simple(struct inode *inode, loff_t size) +{ + loff_t pos = size - 1; + pgoff_t index = pos >> PAGE_CACHE_SHIFT; + unsigned int offset = (pos & (PAGE_CACHE_SIZE - 1)) + 1; + + /* prepare/commit_write can handle even if from==to==start of block. */ + return __generic_cont_expand(inode, size, index, offset); +} + /* * For moronic filesystems that do not allow holes in file. * We may have to extend the file. @@ -2311,7 +2341,7 @@ int generic_commit_write(struct file *file, struct page *page, __block_commit_write(inode,page,from,to); /* * No need to use i_size_read() here, the i_size - * cannot change under us because we hold i_sem. + * cannot change under us because we hold i_mutex. */ if (pos > inode->i_size) { i_size_write(inode, pos); @@ -2385,6 +2415,7 @@ int nobh_prepare_write(struct page *page, unsigned from, unsigned to, create = 1; if (block_start >= to) create = 0; + map_bh.b_size = blocksize; ret = get_block(inode, block_in_file + block_in_page, &map_bh, create); if (ret) @@ -2508,6 +2539,61 @@ int nobh_commit_write(struct file *file, struct page *page, } EXPORT_SYMBOL(nobh_commit_write); +/* + * nobh_writepage() - based on block_full_write_page() except + * that it tries to operate without attaching bufferheads to + * the page. + */ +int nobh_writepage(struct page *page, get_block_t *get_block, + struct writeback_control *wbc) +{ + struct inode * const inode = page->mapping->host; + loff_t i_size = i_size_read(inode); + const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; + unsigned offset; + void *kaddr; + int ret; + + /* Is the page fully inside i_size? */ + if (page->index < end_index) + goto out; + + /* Is the page fully outside i_size? (truncate in progress) */ + offset = i_size & (PAGE_CACHE_SIZE-1); + if (page->index >= end_index+1 || !offset) { + /* + * The page may have dirty, unmapped buffers. For example, + * they may have been added in ext3_writepage(). Make them + * freeable here, so the page does not leak. + */ +#if 0 + /* Not really sure about this - do we need this ? */ + if (page->mapping->a_ops->invalidatepage) + page->mapping->a_ops->invalidatepage(page, offset); +#endif + unlock_page(page); + return 0; /* don't care */ + } + + /* + * The page straddles i_size. It must be zeroed out on each and every + * writepage invocation because it may be mmapped. "A file is mapped + * in multiples of the page size. For a file that is not a multiple of + * the page size, the remaining memory is zeroed when mapped, and + * writes to that region are not written out to the file." + */ + kaddr = kmap_atomic(page, KM_USER0); + memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset); + flush_dcache_page(page); + kunmap_atomic(kaddr, KM_USER0); +out: + ret = mpage_writepage(page, get_block, wbc); + if (ret == -EAGAIN) + ret = __block_write_full_page(inode, page, get_block, wbc); + return ret; +} +EXPORT_SYMBOL(nobh_writepage); + /* * This function assumes that ->prepare_write() uses nobh_prepare_write(). */ @@ -2553,7 +2639,7 @@ int block_truncate_page(struct address_space *mapping, pgoff_t index = from >> PAGE_CACHE_SHIFT; unsigned offset = from & (PAGE_CACHE_SIZE-1); unsigned blocksize; - pgoff_t iblock; + sector_t iblock; unsigned length, pos; struct inode *inode = mapping->host; struct page *page; @@ -2569,7 +2655,7 @@ int block_truncate_page(struct address_space *mapping, return 0; length = blocksize - length; - iblock = index << (PAGE_CACHE_SHIFT - inode->i_blkbits); + iblock = (sector_t)index << (PAGE_CACHE_SHIFT - inode->i_blkbits); page = grab_cache_page(mapping, index); err = -ENOMEM; @@ -2590,6 +2676,7 @@ int block_truncate_page(struct address_space *mapping, err = 0; if (!buffer_mapped(bh)) { + WARN_ON(bh->b_size != blocksize); err = get_block(inode, iblock, bh, 0); if (err) goto unlock; @@ -2650,7 +2737,7 @@ int block_write_full_page(struct page *page, get_block_t *get_block, * they may have been added in ext3_writepage(). Make them * freeable here, so the page does not leak. */ - block_invalidatepage(page, 0); + do_invalidatepage(page, 0); unlock_page(page); return 0; /* don't care */ } @@ -2676,6 +2763,7 @@ sector_t generic_block_bmap(struct address_space *mapping, sector_t block, struct inode *inode = mapping->host; tmp.b_state = 0; tmp.b_blocknr = 0; + tmp.b_size = 1 << inode->i_blkbits; get_block(inode, block, &tmp, 0); return tmp.b_blocknr; } @@ -2747,21 +2835,22 @@ int submit_bh(int rw, struct buffer_head * bh) /** * ll_rw_block: low-level access to block devices (DEPRECATED) - * @rw: whether to %READ or %WRITE or maybe %READA (readahead) + * @rw: whether to %READ or %WRITE or %SWRITE or maybe %READA (readahead) * @nr: number of &struct buffer_heads in the array * @bhs: array of pointers to &struct buffer_head * - * ll_rw_block() takes an array of pointers to &struct buffer_heads, - * and requests an I/O operation on them, either a %READ or a %WRITE. - * The third %READA option is described in the documentation for - * generic_make_request() which ll_rw_block() calls. + * ll_rw_block() takes an array of pointers to &struct buffer_heads, and + * requests an I/O operation on them, either a %READ or a %WRITE. The third + * %SWRITE is like %WRITE only we make sure that the *current* data in buffers + * are sent to disk. The fourth %READA option is described in the documentation + * for generic_make_request() which ll_rw_block() calls. * * This function drops any buffer that it cannot get a lock on (with the - * BH_Lock state bit), any buffer that appears to be clean when doing a - * write request, and any buffer that appears to be up-to-date when doing - * read request. Further it marks as clean buffers that are processed for - * writing (the buffer cache won't assume that they are actually clean until - * the buffer gets unlocked). + * BH_Lock state bit) unless SWRITE is required, any buffer that appears to be + * clean when doing a write request, and any buffer that appears to be + * up-to-date when doing read request. Further it marks as clean buffers that + * are processed for writing (the buffer cache won't assume that they are + * actually clean until the buffer gets unlocked). * * ll_rw_block sets b_end_io to simple completion handler that marks * the buffer up-to-date (if approriate), unlocks the buffer and wakes @@ -2777,25 +2866,27 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[]) for (i = 0; i < nr; i++) { struct buffer_head *bh = bhs[i]; - if (test_set_buffer_locked(bh)) + if (rw == SWRITE) + lock_buffer(bh); + else if (test_set_buffer_locked(bh)) continue; - get_bh(bh); - if (rw == WRITE) { - bh->b_end_io = end_buffer_write_sync; + if (rw == WRITE || rw == SWRITE) { if (test_clear_buffer_dirty(bh)) { + bh->b_end_io = end_buffer_write_sync; + get_bh(bh); submit_bh(WRITE, bh); continue; } } else { - bh->b_end_io = end_buffer_read_sync; if (!buffer_uptodate(bh)) { + bh->b_end_io = end_buffer_read_sync; + get_bh(bh); submit_bh(rw, bh); continue; } } unlock_buffer(bh); - put_bh(bh); } } @@ -2861,7 +2952,7 @@ drop_buffers(struct page *page, struct buffer_head **buffers_to_free) bh = head; do { - if (buffer_write_io_error(bh)) + if (buffer_write_io_error(bh) && page->mapping) set_bit(AS_EIO, &page->mapping->flags); if (buffer_busy(bh)) goto failed; @@ -2925,7 +3016,7 @@ out: } EXPORT_SYMBOL(try_to_free_buffers); -int block_sync_page(struct page *page) +void block_sync_page(struct page *page) { struct address_space *mapping; @@ -2933,7 +3024,6 @@ int block_sync_page(struct page *page) mapping = page_mapping(page); if (mapping) blk_run_backing_dev(mapping->backing_dev_info, page); - return 0; } /* @@ -2991,19 +3081,18 @@ static void recalc_bh_state(void) if (__get_cpu_var(bh_accounting).ratelimit++ < 4096) return; __get_cpu_var(bh_accounting).ratelimit = 0; - for_each_cpu(i) + for_each_online_cpu(i) tot += per_cpu(bh_accounting, i).nr; buffer_heads_over_limit = (tot > max_buffer_heads); } -struct buffer_head *alloc_buffer_head(int gfp_flags) +struct buffer_head *alloc_buffer_head(gfp_t gfp_flags) { struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags); if (ret) { - preempt_disable(); - __get_cpu_var(bh_accounting).nr++; + get_cpu_var(bh_accounting).nr++; recalc_bh_state(); - preempt_enable(); + put_cpu_var(bh_accounting); } return ret; } @@ -3013,10 +3102,9 @@ void free_buffer_head(struct buffer_head *bh) { BUG_ON(!list_empty(&bh->b_assoc_buffers)); kmem_cache_free(bh_cachep, bh); - preempt_disable(); - __get_cpu_var(bh_accounting).nr--; + get_cpu_var(bh_accounting).nr--; recalc_bh_state(); - preempt_enable(); + put_cpu_var(bh_accounting); } EXPORT_SYMBOL(free_buffer_head); @@ -3042,6 +3130,9 @@ static void buffer_exit_cpu(int cpu) brelse(b->bhs[i]); b->bhs[i] = NULL; } + get_cpu_var(bh_accounting).nr += per_cpu(bh_accounting, cpu).nr; + per_cpu(bh_accounting, cpu).nr = 0; + put_cpu_var(bh_accounting); } static int buffer_cpu_notify(struct notifier_block *self, @@ -3058,8 +3149,11 @@ void __init buffer_init(void) int nrpages; bh_cachep = kmem_cache_create("buffer_head", - sizeof(struct buffer_head), 0, - SLAB_PANIC, init_buffer_head, NULL); + sizeof(struct buffer_head), 0, + (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| + SLAB_MEM_SPREAD), + init_buffer_head, + NULL); /* * Limit the bh occupancy to 10% of ZONE_NORMAL @@ -3087,6 +3181,7 @@ EXPORT_SYMBOL(fsync_bdev); EXPORT_SYMBOL(generic_block_bmap); EXPORT_SYMBOL(generic_commit_write); EXPORT_SYMBOL(generic_cont_expand); +EXPORT_SYMBOL(generic_cont_expand_simple); EXPORT_SYMBOL(init_buffer); EXPORT_SYMBOL(invalidate_bdev); EXPORT_SYMBOL(ll_rw_block);