Beispiel #1
0
static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc)
{
	int err;
	struct buffer_head *bh, *head;
	int nr_underway = 0;
	int write_op = (1 << BIO_RW_META) | ((wbc->sync_mode == WB_SYNC_ALL ?
			WRITE_SYNC_PLUG : WRITE));

	BUG_ON(!PageLocked(page));
	BUG_ON(!page_has_buffers(page));

	head = page_buffers(page);
	bh = head;

	do {
		if (!buffer_mapped(bh))
			continue;
		/*
		 * If it's a fully non-blocking write attempt and we cannot
		 * lock the buffer then redirty the page.  Note that this can
		 * potentially cause a busy-wait loop from pdflush and kswapd
		 * activity, but those code paths have their own higher-level
		 * throttling.
		 */
		if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
			lock_buffer(bh);
		} else if (!trylock_buffer(bh)) {
			redirty_page_for_writepage(wbc, page);
			continue;
		}
		if (test_clear_buffer_dirty(bh)) {
			mark_buffer_async_write(bh);
		} else {
			unlock_buffer(bh);
		}
	} while ((bh = bh->b_this_page) != head);

	/*
	 * The page and its buffers are protected by PageWriteback(), so we can
	 * drop the bh refcounts early.
	 */
	BUG_ON(PageWriteback(page));
	set_page_writeback(page);

	do {
		struct buffer_head *next = bh->b_this_page;
		if (buffer_async_write(bh)) {
			submit_bh(write_op, bh);
			nr_underway++;
		}
		bh = next;
	} while (bh != head);
	unlock_page(page);

	err = 0;
	if (nr_underway == 0)
		end_page_writeback(page);

	return err;
}
Beispiel #2
0
static void gfs2_metapath_ra(struct gfs2_glock *gl,
			     const struct buffer_head *bh, const __be64 *pos)
{
	struct buffer_head *rabh;
	const __be64 *endp = (const __be64 *)(bh->b_data + bh->b_size);
	const __be64 *t;

	for (t = pos; t < endp; t++) {
		if (!*t)
			continue;

		rabh = gfs2_getbuf(gl, be64_to_cpu(*t), CREATE);
		if (trylock_buffer(rabh)) {
			if (!buffer_uptodate(rabh)) {
				rabh->b_end_io = end_buffer_read_sync;
				submit_bh(REQ_OP_READ,
					  REQ_RAHEAD | REQ_META | REQ_PRIO,
					  rabh);
				continue;
			}
			unlock_buffer(rabh);
		}
		brelse(rabh);
	}
}
Beispiel #3
0
static int
nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff,
		       int mode, struct buffer_head **out_bh)
{
	struct buffer_head *bh;
	unsigned long blknum = 0;
	int ret = -ENOMEM;

	bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
	if (unlikely(!bh))
		goto failed;

	ret = -EEXIST; /* internal code */
	if (buffer_uptodate(bh))
		goto out;

	if (mode == READA) {
		if (!trylock_buffer(bh)) {
			ret = -EBUSY;
			goto failed_bh;
		}
	} else /* mode == READ */
		lock_buffer(bh);

	if (buffer_uptodate(bh)) {
		unlock_buffer(bh);
		goto out;
	}
	if (!buffer_mapped(bh)) { /* unused buffer */
		ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff,
					&blknum);
		if (unlikely(ret)) {
			unlock_buffer(bh);
			goto failed_bh;
		}
		bh->b_bdev = NILFS_MDT(inode)->mi_nilfs->ns_bdev;
		bh->b_blocknr = blknum;
		set_buffer_mapped(bh);
	}

	bh->b_end_io = end_buffer_read_sync;
	get_bh(bh);
	submit_bh(mode, bh);
	ret = 0;
 out:
	get_bh(bh);
	*out_bh = bh;

 failed_bh:
	unlock_page(bh->b_page);
	page_cache_release(bh->b_page);
	brelse(bh);
 failed:
	return ret;
}
Beispiel #4
0
static int
nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff,
		       int mode, int mode_flags, struct buffer_head **out_bh)
{
	struct buffer_head *bh;
	__u64 blknum = 0;
	int ret = -ENOMEM;

	bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
	if (unlikely(!bh))
		goto failed;

	ret = -EEXIST; /* internal code */
	if (buffer_uptodate(bh))
		goto out;

	if (mode_flags & REQ_RAHEAD) {
		if (!trylock_buffer(bh)) {
			ret = -EBUSY;
			goto failed_bh;
		}
	} else /* mode == READ */
		lock_buffer(bh);

	if (buffer_uptodate(bh)) {
		unlock_buffer(bh);
		goto out;
	}

	ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum);
	if (unlikely(ret)) {
		unlock_buffer(bh);
		goto failed_bh;
	}
	map_bh(bh, inode->i_sb, (sector_t)blknum);

	bh->b_end_io = end_buffer_read_sync;
	get_bh(bh);
	submit_bh(mode, mode_flags, bh);
	ret = 0;

	trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff, mode);
 out:
	get_bh(bh);
	*out_bh = bh;

 failed_bh:
	unlock_page(bh->b_page);
	put_page(bh->b_page);
	brelse(bh);
 failed:
	return ret;
}
static int jread(struct buffer_head **bhp, journal_t *journal,
		 unsigned int offset)
{
	int err;
	unsigned long long blocknr;
	struct buffer_head *bh;

	*bhp = NULL;

	if (offset >= journal->j_maxlen) {
		printk(KERN_ERR "JBD: corrupted journal superblock\n");
		return -EIO;
	}

	err = jbd2_journal_bmap(journal, offset, &blocknr);

	if (err) {
		printk (KERN_ERR "JBD: bad block at offset %u\n",
			offset);
		return err;
	}

	bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
	if (!bh)
		return -ENOMEM;

	if(buffer_uptodate(bh)){
		if (!trylock_buffer(bh)){
			lock_buffer(bh);
			printk("debug:concurrent exist \n");
		}
		unlock_buffer(bh);
	}
	if (!buffer_uptodate(bh)) {
		/* If this is a brand new buffer, start readahead.
                   Otherwise, we assume we are already reading it.  */
		if (!buffer_req(bh))
			do_readahead(journal, offset);
		wait_on_buffer(bh);
	}

	if (!buffer_uptodate(bh)) {
		printk (KERN_ERR "JBD: Failed to read block at offset %u\n",
			offset);
		brelse(bh);
		return -EIO;
	}

	*bhp = bh;
	return 0;
}
int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr,
			      sector_t pblocknr, int mode,
			      struct buffer_head **pbh, sector_t *submit_ptr)
{
	struct buffer_head *bh;
	struct inode *inode = NILFS_BTNC_I(btnc);
	struct page *page;
	int err;

	bh = nilfs_grab_buffer(inode, btnc, blocknr, 1 << BH_NILFS_Node);
	if (unlikely(!bh))
		return -ENOMEM;

	err = -EEXIST; 
	page = bh->b_page;

	if (buffer_uptodate(bh) || buffer_dirty(bh))
		goto found;

	if (pblocknr == 0) {
		pblocknr = blocknr;
		if (inode->i_ino != NILFS_DAT_INO) {
			struct the_nilfs *nilfs = inode->i_sb->s_fs_info;

			
			err = nilfs_dat_translate(nilfs->ns_dat, blocknr,
						  &pblocknr);
			if (unlikely(err)) {
				brelse(bh);
				goto out_locked;
			}
		}
	}

	if (mode == READA) {
		if (pblocknr != *submit_ptr + 1 || !trylock_buffer(bh)) {
			err = -EBUSY; 
			brelse(bh);
			goto out_locked;
		}
	} else { 
		lock_buffer(bh);
	}
	if (buffer_uptodate(bh)) {
		unlock_buffer(bh);
		err = -EEXIST; 
		goto found;
	}
	set_buffer_mapped(bh);
	bh->b_bdev = inode->i_sb->s_bdev;
	bh->b_blocknr = pblocknr; 
	bh->b_end_io = end_buffer_read_sync;
	get_bh(bh);
	submit_bh(mode, bh);
	bh->b_blocknr = blocknr; 
	*submit_ptr = pblocknr;
	err = 0;
found:
	*pbh = bh;

out_locked:
	unlock_page(page);
	page_cache_release(page);
	return err;
}
Beispiel #7
0
/*
 *  Submit all the data buffers to disk
 */
static int journal_submit_data_buffers(journal_t *journal,
				       transaction_t *commit_transaction,
				       int write_op)
{
	struct journal_head *jh;
	struct buffer_head *bh;
	int locked;
	int bufs = 0;
	struct buffer_head **wbuf = journal->j_wbuf;
	int err = 0;

	/*
	 * Whenever we unlock the journal and sleep, things can get added
	 * onto ->t_sync_datalist, so we have to keep looping back to
	 * write_out_data until we *know* that the list is empty.
	 *
	 * Cleanup any flushed data buffers from the data list.  Even in
	 * abort mode, we want to flush this out as soon as possible.
	 */
write_out_data:
	cond_resched();
	spin_lock(&journal->j_list_lock);

	while (commit_transaction->t_sync_datalist) {
		jh = commit_transaction->t_sync_datalist;
		bh = jh2bh(jh);
		locked = 0;

		/* Get reference just to make sure buffer does not disappear
		 * when we are forced to drop various locks */
		get_bh(bh);
		/* If the buffer is dirty, we need to submit IO and hence
		 * we need the buffer lock. We try to lock the buffer without
		 * blocking. If we fail, we need to drop j_list_lock and do
		 * blocking lock_buffer().
		 */
		if (buffer_dirty(bh)) {
			if (!trylock_buffer(bh)) {
				BUFFER_TRACE(bh, "needs blocking lock");
				spin_unlock(&journal->j_list_lock);
				trace_jbd_do_submit_data(journal,
						     commit_transaction);
				/* Write out all data to prevent deadlocks */
				journal_do_submit_data(wbuf, bufs, write_op);
				bufs = 0;
				lock_buffer(bh);
				spin_lock(&journal->j_list_lock);
			}
			locked = 1;
		}
		/* We have to get bh_state lock. Again out of order, sigh. */
		if (!inverted_lock(journal, bh)) {
			jbd_lock_bh_state(bh);
			spin_lock(&journal->j_list_lock);
		}
		/* Someone already cleaned up the buffer? */
		if (!buffer_jbd(bh) || bh2jh(bh) != jh
			|| jh->b_transaction != commit_transaction
			|| jh->b_jlist != BJ_SyncData) {
			jbd_unlock_bh_state(bh);
			if (locked)
				unlock_buffer(bh);
			BUFFER_TRACE(bh, "already cleaned up");
			release_data_buffer(bh);
			continue;
		}
		if (locked && test_clear_buffer_dirty(bh)) {
			BUFFER_TRACE(bh, "needs writeout, adding to array");
			wbuf[bufs++] = bh;
			__journal_file_buffer(jh, commit_transaction,
						BJ_Locked);
			jbd_unlock_bh_state(bh);
			if (bufs == journal->j_wbufsize) {
				spin_unlock(&journal->j_list_lock);
				trace_jbd_do_submit_data(journal,
						     commit_transaction);
				journal_do_submit_data(wbuf, bufs, write_op);
				bufs = 0;
				goto write_out_data;
			}
		} else if (!locked && buffer_locked(bh)) {
			__journal_file_buffer(jh, commit_transaction,
						BJ_Locked);
			jbd_unlock_bh_state(bh);
			put_bh(bh);
		} else {
			BUFFER_TRACE(bh, "writeout complete: unfile");
			if (unlikely(!buffer_uptodate(bh)))
				err = -EIO;
			__journal_unfile_buffer(jh);
			jbd_unlock_bh_state(bh);
			if (locked)
				unlock_buffer(bh);
			release_data_buffer(bh);
		}

		if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
			spin_unlock(&journal->j_list_lock);
			goto write_out_data;
		}
	}
	spin_unlock(&journal->j_list_lock);
	trace_jbd_do_submit_data(journal, commit_transaction);
	journal_do_submit_data(wbuf, bufs, write_op);

	return err;
}
Beispiel #8
0
int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr,
			      sector_t pblocknr, int mode, int mode_flags,
			      struct buffer_head **pbh, sector_t *submit_ptr)
{
	struct buffer_head *bh;
	struct inode *inode = NILFS_BTNC_I(btnc);
	struct page *page;
	int err;

	bh = nilfs_grab_buffer(inode, btnc, blocknr, BIT(BH_NILFS_Node));
	if (unlikely(!bh))
		return -ENOMEM;

	err = -EEXIST; /* internal code */
	page = bh->b_page;

	if (buffer_uptodate(bh) || buffer_dirty(bh))
		goto found;

	if (pblocknr == 0) {
		pblocknr = blocknr;
		if (inode->i_ino != NILFS_DAT_INO) {
			struct the_nilfs *nilfs = inode->i_sb->s_fs_info;

			/* blocknr is a virtual block number */
			err = nilfs_dat_translate(nilfs->ns_dat, blocknr,
						  &pblocknr);
			if (unlikely(err)) {
				brelse(bh);
				goto out_locked;
			}
		}
	}

	if (mode_flags & REQ_RAHEAD) {
		if (pblocknr != *submit_ptr + 1 || !trylock_buffer(bh)) {
			err = -EBUSY; /* internal code */
			brelse(bh);
			goto out_locked;
		}
	} else { /* mode == READ */
		lock_buffer(bh);
	}
	if (buffer_uptodate(bh)) {
		unlock_buffer(bh);
		err = -EEXIST; /* internal code */
		goto found;
	}
	set_buffer_mapped(bh);
	bh->b_bdev = inode->i_sb->s_bdev;
	bh->b_blocknr = pblocknr; /* set block address for read */
	bh->b_end_io = end_buffer_read_sync;
	get_bh(bh);
	submit_bh(mode, mode_flags, bh);
	bh->b_blocknr = blocknr; /* set back to the given block address */
	*submit_ptr = pblocknr;
	err = 0;
found:
	*pbh = bh;

out_locked:
	unlock_page(page);
	put_page(page);
	return err;
}