From: Mingming Cao <cmm@xxxxxxxxxx> Inverse locking ordering of page_lock and transaction start in delalloc Signed-off-by: Mingming Cao <cmm@xxxxxxxxxx> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> --- fs/ext4/inode.c | 96 +++++++++++++++++++++++++++++++++++++++---------------- 1 files changed, 68 insertions(+), 28 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 62b38b6..65e02a3 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1448,18 +1448,14 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, static int ext4_da_get_block_write(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { - int ret, needed_blocks = ext4_writepage_trans_blocks(inode); + int ret; unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; loff_t disksize = EXT4_I(inode)->i_disksize; handle_t *handle = NULL; - if (create) { - handle = ext4_journal_start(inode, needed_blocks); - if (IS_ERR(handle)) { - ret = PTR_ERR(handle); - goto out; - } - } + handle = ext4_journal_current_handle(); + BUG_ON(handle == 0); + BUG_ON(create == 0); ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks, bh_result, create, 0); @@ -1494,29 +1490,17 @@ static int ext4_da_get_block_write(struct inode *inode, sector_t iblock, ret = 0; } -out: - if (handle && !IS_ERR(handle)) - ext4_journal_stop(handle); - return ret; } /* FIXME!! only support data=writeback mode */ -static int ext4_da_writepage(struct page *page, +static int __ext4_da_writepage(struct page *page, struct writeback_control *wbc) { struct inode *inode = page->mapping->host; handle_t *handle = NULL; int ret = 0; - int err; - - if (ext4_journal_current_handle()) - goto out_fail; - handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode)); - if (IS_ERR(handle)) { - ret = PTR_ERR(handle); - goto out_fail; - } + handle = ext4_journal_current_handle(); if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode)) ret = nobh_writepage(page, ext4_get_block, wbc); @@ -1528,21 +1512,77 @@ static int ext4_da_writepage(struct page *page, ext4_mark_inode_dirty(handle, inode); } - err = ext4_journal_stop(handle); - if (!ret) - ret = err; return ret; +} +static int ext4_da_writepage(struct page *page, + struct writeback_control *wbc) +{ + if (!ext4_journal_current_handle()) + return __ext4_da_writepage(page, wbc); -out_fail: redirty_page_for_writepage(wbc, page); unlock_page(page); - return ret; + return 0; } +/* + * For now just follow the DIO way to estimate the max credits + * needed to write out EXT4_MAX_WRITEBACK_PAGES. + * todo: need to calculate the max credits need for + * extent based files, currently the DIO credits is based on + * indirect-blocks mapping way. + * + * Probably should have a generic way to calculate credits + * for DIO, writepages, and truncate + */ +#define EXT4_MAX_WRITEBACK_PAGES DIO_MAX_BLOCKS +#define EXT4_MAX_WRITEBACK_CREDITS DIO_CREDITS + static int ext4_da_writepages(struct address_space *mapping, struct writeback_control *wbc) { - return mpage_da_writepages(mapping, wbc, ext4_da_get_block_write); + struct inode *inode = mapping->host; + handle_t *handle = NULL; + int needed_blocks; + int ret = 0; + unsigned range_cyclic; + long to_write; + + /* + * Estimate the worse case needed credits to write out + * EXT4_MAX_BUF_BLOCKS pages + */ + needed_blocks = EXT4_MAX_WRITEBACK_CREDITS; + + to_write = wbc->nr_to_write; + range_cyclic = wbc->range_cyclic; + wbc->range_cyclic = 1; + + while (!ret && to_write) { + /* start a new transaction*/ + handle = ext4_journal_start(inode, needed_blocks); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + goto out_writepages; + } + /* + * set the max dirty pages could be write at a time + * to fit into the reserved transaction credits + */ + if (wbc->nr_to_write > EXT4_MAX_WRITEBACK_PAGES) + wbc->nr_to_write = EXT4_MAX_WRITEBACK_PAGES; + to_write -= wbc->nr_to_write; + + ret = mpage_da_writepages(mapping, wbc, + ext4_da_get_block_write); + ext4_journal_stop(handle); + to_write += wbc->nr_to_write; + } + +out_writepages: + wbc->nr_to_write = to_write; + wbc->range_cyclic = range_cyclic; + return ret; } static int ext4_da_write_begin(struct file *file, struct address_space *mapping, -- 1.5.5.1.357.g1af8b.dirty -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html