From a549984b8c95acbecefd1fdd4bfdbea4d29b0588 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 11 May 2013 19:07:42 -0400 Subject: ext4: revert "ext4: use io_end for multiple bios" This reverts commit 4eec708d263f0ee10861d69251708a225b64cac7. Multiple users have reported crashes which is apparently caused by this commit. Thanks to Dmitry Monakhov for bisecting it. Signed-off-by: "Theodore Ts'o" Cc: Dmitry Monakhov Cc: Jan Kara --- fs/ext4/page-io.c | 121 ++++++++++++++++++++---------------------------------- 1 file changed, 45 insertions(+), 76 deletions(-) (limited to 'fs/ext4/page-io.c') diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 5929cd0baa20..6626aba57ebb 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -61,28 +61,15 @@ void ext4_ioend_shutdown(struct inode *inode) cancel_work_sync(&EXT4_I(inode)->i_unwritten_work); } -static void ext4_release_io_end(ext4_io_end_t *io_end) +void ext4_free_io_end(ext4_io_end_t *io) { - BUG_ON(!list_empty(&io_end->list)); - BUG_ON(io_end->flag & EXT4_IO_END_UNWRITTEN); - - if (atomic_dec_and_test(&EXT4_I(io_end->inode)->i_ioend_count)) - wake_up_all(ext4_ioend_wq(io_end->inode)); - if (io_end->flag & EXT4_IO_END_DIRECT) - inode_dio_done(io_end->inode); - if (io_end->iocb) - aio_complete(io_end->iocb, io_end->result, 0); - kmem_cache_free(io_end_cachep, io_end); -} - -static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end) -{ - struct inode *inode = io_end->inode; + BUG_ON(!io); + BUG_ON(!list_empty(&io->list)); + BUG_ON(io->flag & EXT4_IO_END_UNWRITTEN); - io_end->flag &= ~EXT4_IO_END_UNWRITTEN; - /* Wake up anyone waiting on unwritten extent conversion */ - if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) - wake_up_all(ext4_ioend_wq(inode)); + if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count)) + wake_up_all(ext4_ioend_wq(io->inode)); + kmem_cache_free(io_end_cachep, io); } /* check a range of space and convert unwritten extents to written. */ @@ -105,8 +92,13 @@ static int ext4_end_io(ext4_io_end_t *io) "(inode %lu, offset %llu, size %zd, error %d)", inode->i_ino, offset, size, ret); } - ext4_clear_io_unwritten_flag(io); - ext4_release_io_end(io); + /* Wake up anyone waiting on unwritten extent conversion */ + if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) + wake_up_all(ext4_ioend_wq(inode)); + if (io->flag & EXT4_IO_END_DIRECT) + inode_dio_done(inode); + if (io->iocb) + aio_complete(io->iocb, io->result, 0); return ret; } @@ -137,7 +129,7 @@ static void dump_completed_IO(struct inode *inode) } /* Add the io_end to per-inode completed end_io list. */ -static void ext4_add_complete_io(ext4_io_end_t *io_end) +void ext4_add_complete_io(ext4_io_end_t *io_end) { struct ext4_inode_info *ei = EXT4_I(io_end->inode); struct workqueue_struct *wq; @@ -174,6 +166,8 @@ static int ext4_do_flush_completed_IO(struct inode *inode) err = ext4_end_io(io); if (unlikely(!ret && err)) ret = err; + io->flag &= ~EXT4_IO_END_UNWRITTEN; + ext4_free_io_end(io); } return ret; } @@ -205,43 +199,10 @@ ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) atomic_inc(&EXT4_I(inode)->i_ioend_count); io->inode = inode; INIT_LIST_HEAD(&io->list); - atomic_set(&io->count, 1); } return io; } -void ext4_put_io_end_defer(ext4_io_end_t *io_end) -{ - if (atomic_dec_and_test(&io_end->count)) { - if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) { - ext4_release_io_end(io_end); - return; - } - ext4_add_complete_io(io_end); - } -} - -int ext4_put_io_end(ext4_io_end_t *io_end) -{ - int err = 0; - - if (atomic_dec_and_test(&io_end->count)) { - if (io_end->flag & EXT4_IO_END_UNWRITTEN) { - err = ext4_convert_unwritten_extents(io_end->inode, - io_end->offset, io_end->size); - ext4_clear_io_unwritten_flag(io_end); - } - ext4_release_io_end(io_end); - } - return err; -} - -ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end) -{ - atomic_inc(&io_end->count); - return io_end; -} - /* * Print an buffer I/O error compatible with the fs/buffer.c. This * provides compatibility with dmesg scrapers that look for a specific @@ -324,7 +285,12 @@ static void ext4_end_bio(struct bio *bio, int error) bi_sector >> (inode->i_blkbits - 9)); } - ext4_put_io_end_defer(io_end); + if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { + ext4_free_io_end(io_end); + return; + } + + ext4_add_complete_io(io_end); } void ext4_io_submit(struct ext4_io_submit *io) @@ -338,37 +304,40 @@ void ext4_io_submit(struct ext4_io_submit *io) bio_put(io->io_bio); } io->io_bio = NULL; -} - -void ext4_io_submit_init(struct ext4_io_submit *io, - struct writeback_control *wbc) -{ - io->io_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); - io->io_bio = NULL; + io->io_op = 0; io->io_end = NULL; } -static int io_submit_init_bio(struct ext4_io_submit *io, - struct buffer_head *bh) +static int io_submit_init(struct ext4_io_submit *io, + struct inode *inode, + struct writeback_control *wbc, + struct buffer_head *bh) { + ext4_io_end_t *io_end; + struct page *page = bh->b_page; int nvecs = bio_get_nr_vecs(bh->b_bdev); struct bio *bio; + io_end = ext4_init_io_end(inode, GFP_NOFS); + if (!io_end) + return -ENOMEM; bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9); bio->bi_bdev = bh->b_bdev; + bio->bi_private = io->io_end = io_end; bio->bi_end_io = ext4_end_bio; - bio->bi_private = ext4_get_io_end(io->io_end); - if (!io->io_end->size) - io->io_end->offset = (bh->b_page->index << PAGE_CACHE_SHIFT) - + bh_offset(bh); + + io_end->offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(bh); + io->io_bio = bio; + io->io_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); io->io_next_block = bh->b_blocknr; return 0; } static int io_submit_add_bh(struct ext4_io_submit *io, struct inode *inode, + struct writeback_control *wbc, struct buffer_head *bh) { ext4_io_end_t *io_end; @@ -379,18 +348,18 @@ submit_and_retry: ext4_io_submit(io); } if (io->io_bio == NULL) { - ret = io_submit_init_bio(io, bh); + ret = io_submit_init(io, inode, wbc, bh); if (ret) return ret; } - ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh)); - if (ret != bh->b_size) - goto submit_and_retry; io_end = io->io_end; if (test_clear_buffer_uninit(bh)) ext4_set_io_unwritten_flag(inode, io_end); - io_end->size += bh->b_size; + io->io_end->size += bh->b_size; io->io_next_block++; + ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh)); + if (ret != bh->b_size) + goto submit_and_retry; return 0; } @@ -462,7 +431,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io, do { if (!buffer_async_write(bh)) continue; - ret = io_submit_add_bh(io, inode, bh); + ret = io_submit_add_bh(io, inode, wbc, bh); if (ret) { /* * We only get here on ENOMEM. Not much else -- cgit v1.2.3-59-g8ed1b