diff options
| -rw-r--r-- | fs/ext4/ext4.h | 10 | ||||
| -rw-r--r-- | fs/ext4/extents.c | 35 | ||||
| -rw-r--r-- | fs/ext4/inode.c | 133 |
3 files changed, 74 insertions, 104 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index d60db18edb4a..9f3156c38b16 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1513,16 +1513,6 @@ static inline void ext4_set_io_unwritten_flag(struct inode *inode, } } -static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode) -{ - return inode->i_private; -} - -static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io) -{ - inode->i_private = io; -} - /* * Inode dynamic state flags */ diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 73a48c1657a1..f1b3c2586a1a 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -1736,6 +1736,12 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, */ if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN) return 0; + /* + * The check for IO to unwritten extent is somewhat racy as we + * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after + * dropping i_data_sem. But reserved blocks should save us in that + * case. + */ if (ext4_ext_is_unwritten(ex1) && (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) || atomic_read(&EXT4_I(inode)->i_unwritten) || @@ -4007,7 +4013,6 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, struct ext4_ext_path *path = *ppath; int ret = 0; int err = 0; - ext4_io_end_t *io = ext4_inode_aio(inode); ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical " "block %llu, max_blocks %u, flags %x, allocated %u\n", @@ -4030,15 +4035,6 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, flags | EXT4_GET_BLOCKS_CONVERT); if (ret <= 0) goto out; - /* - * Flag the inode(non aio case) or end_io struct (aio case) - * that this IO needs to conversion to written when IO is - * completed - */ - if (io) - ext4_set_io_unwritten_flag(inode, io); - else - ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); map->m_flags |= EXT4_MAP_UNWRITTEN; goto out; } @@ -4283,9 +4279,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, unsigned int allocated = 0, offset = 0; unsigned int allocated_clusters = 0; struct ext4_allocation_request ar; - ext4_io_end_t *io = ext4_inode_aio(inode); ext4_lblk_t cluster_offset; - int set_unwritten = 0; bool map_from_cluster = false; ext_debug("blocks %u/%u requested for inode %lu\n", @@ -4482,15 +4476,6 @@ got_allocated_blocks: if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){ ext4_ext_mark_unwritten(&newex); map->m_flags |= EXT4_MAP_UNWRITTEN; - /* - * io_end structure was created for every IO write to an - * unwritten extent. To avoid unnecessary conversion, - * here we flag the IO that really needs the conversion. - * For non asycn direct IO case, flag the inode state - * that we need to perform conversion when IO is done. - */ - if (flags & EXT4_GET_BLOCKS_PRE_IO) - set_unwritten = 1; } err = 0; @@ -4501,14 +4486,6 @@ got_allocated_blocks: err = ext4_ext_insert_extent(handle, inode, &path, &newex, flags); - if (!err && set_unwritten) { - if (io) - ext4_set_io_unwritten_flag(inode, io); - else - ext4_set_inode_state(inode, - EXT4_STATE_DIO_UNWRITTEN); - } - if (err && free_on_err) { int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ? EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index aea67d906cd8..c67c16e59a71 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -797,18 +797,16 @@ int ext4_dio_get_block(struct inode *inode, sector_t iblock, } /* - * Get block function for DIO writes when we create unwritten extent if + * Get block function for AIO DIO writes when we create unwritten extent if * blocks are not allocated yet. The extent will be converted to written * after IO is complete. */ -static int ext4_dio_get_block_unwritten(struct inode *inode, sector_t iblock, - struct buffer_head *bh_result, int create) +static int ext4_dio_get_block_unwritten_async(struct inode *inode, + sector_t iblock, struct buffer_head *bh_result, int create) { handle_t *handle; int ret; - ext4_debug("ext4_dio_get_block_unwritten: inode %lu, create flag %d\n", - inode->i_ino, create); /* We don't expect handle for direct IO */ WARN_ON_ONCE(ext4_journal_current_handle()); @@ -818,16 +816,62 @@ static int ext4_dio_get_block_unwritten(struct inode *inode, sector_t iblock, ret = _ext4_get_block(inode, iblock, bh_result, EXT4_GET_BLOCKS_IO_CREATE_EXT); ext4_journal_stop(handle); - if (!ret && buffer_unwritten(bh_result)) { - ext4_io_end_t *io_end = ext4_inode_aio(inode); + /* + * When doing DIO using unwritten extents, we need io_end to convert + * unwritten extents to written on IO completion. We allocate io_end + * once we spot unwritten extent and store it in b_private. Generic + * DIO code keeps b_private set and furthermore passes the value to + * our completion callback in 'private' argument. + */ + if (!ret && buffer_unwritten(bh_result)) { + if (!bh_result->b_private) { + ext4_io_end_t *io_end; + + io_end = ext4_init_io_end(inode, GFP_KERNEL); + if (!io_end) + return -ENOMEM; + bh_result->b_private = io_end; + ext4_set_io_unwritten_flag(inode, io_end); + } set_buffer_defer_completion(bh_result); - WARN_ON_ONCE(io_end && !(io_end->flag & EXT4_IO_END_UNWRITTEN)); } return ret; } +/* + * Get block function for non-AIO DIO writes when we create unwritten extent if + * blocks are not allocated yet. The extent will be converted to written + * after IO is complete from ext4_ext_direct_IO() function. + */ +static int ext4_dio_get_block_unwritten_sync(struct inode *inode, + sector_t iblock, struct buffer_head *bh_result, int create) +{ + handle_t *handle; + int ret; + + /* We don't expect handle for direct IO */ + WARN_ON_ONCE(ext4_journal_current_handle()); + + handle = start_dio_trans(inode, bh_result); + if (IS_ERR(handle)) + return PTR_ERR(handle); + ret = _ext4_get_block(inode, iblock, bh_result, + EXT4_GET_BLOCKS_IO_CREATE_EXT); + ext4_journal_stop(handle); + + /* + * Mark inode as having pending DIO writes to unwritten extents. + * ext4_ext_direct_IO() checks this flag and converts extents to + * written. + */ + if (!ret && buffer_unwritten(bh_result)) + ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); + + return ret; +} + static int ext4_dio_get_block_overwrite(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { @@ -3243,7 +3287,7 @@ out: static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, ssize_t size, void *private) { - ext4_io_end_t *io_end = iocb->private; + ext4_io_end_t *io_end = private; /* if not async direct IO just return */ if (!io_end) @@ -3251,10 +3295,8 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, ext_debug("ext4_end_io_dio(): io_end 0x%p " "for inode %lu, iocb 0x%p, offset %llu, size %zd\n", - iocb->private, io_end->inode->i_ino, iocb, offset, - size); + io_end, io_end->inode->i_ino, iocb, offset, size); - iocb->private = NULL; io_end->offset = offset; io_end->size = size; ext4_put_io_end(io_end); @@ -3290,7 +3332,6 @@ static ssize_t ext4_ext_direct_IO(struct kiocb *iocb, struct iov_iter *iter, get_block_t *get_block_func = NULL; int dio_flags = 0; loff_t final_size = offset + count; - ext4_io_end_t *io_end = NULL; /* Use the old path for reads and writes beyond i_size. */ if (iov_iter_rw(iter) != WRITE || final_size > inode->i_size) @@ -3315,16 +3356,17 @@ static ssize_t ext4_ext_direct_IO(struct kiocb *iocb, struct iov_iter *iter, /* * We could direct write to holes and fallocate. * - * Allocated blocks to fill the hole are marked as - * unwritten to prevent parallel buffered read to expose - * the stale data before DIO complete the data IO. + * Allocated blocks to fill the hole are marked as unwritten to prevent + * parallel buffered read to expose the stale data before DIO complete + * the data IO. * - * As to previously fallocated extents, ext4 get_block will - * just simply mark the buffer mapped but still keep the - * extents unwritten. + * As to previously fallocated extents, ext4 get_block will just simply + * mark the buffer mapped but still keep the extents unwritten. * - * For non AIO case, we will convert those unwritten extents - * to written after return back from blockdev_direct_IO. + * For non AIO case, we will convert those unwritten extents to written + * after return back from blockdev_direct_IO. That way we save us from + * allocating io_end structure and also the overhead of offloading + * the extent convertion to a workqueue. * * For async DIO, the conversion needs to be deferred when the * IO is completed. The ext4 end_io callback function will be @@ -3332,30 +3374,13 @@ static ssize_t ext4_ext_direct_IO(struct kiocb *iocb, struct iov_iter *iter, * case, we allocate an io_end structure to hook to the iocb. */ iocb->private = NULL; - if (overwrite) { + if (overwrite) get_block_func = ext4_dio_get_block_overwrite; + else if (is_sync_kiocb(iocb)) { + get_block_func = ext4_dio_get_block_unwritten_sync; + dio_flags = DIO_LOCKING; } else { - ext4_inode_aio_set(inode, NULL); - if (!is_sync_kiocb(iocb)) { - io_end = ext4_init_io_end(inode, GFP_NOFS); - if (!io_end) { - ret = -ENOMEM; - goto retake_lock; - } - /* - * Grab reference for DIO. Will be dropped in - * ext4_end_io_dio() - */ - iocb->private = ext4_get_io_end(io_end); - /* - * we save the io structure for current async direct - * IO, so that later ext4_map_blocks() could flag the - * io structure whether there is a unwritten extents - * needs to be converted when IO is completed. - */ - ext4_inode_aio_set(inode, io_end); - } - get_block_func = ext4_dio_get_block_unwritten; + get_block_func = ext4_dio_get_block_unwritten_async; dio_flags = DIO_LOCKING; } #ifdef CONFIG_EXT4_FS_ENCRYPTION @@ -3370,27 +3395,6 @@ static ssize_t ext4_ext_direct_IO(struct kiocb *iocb, struct iov_iter *iter, get_block_func, ext4_end_io_dio, NULL, dio_flags); - /* - * Put our reference to io_end. This can free the io_end structure e.g. - * in sync IO case or in case of error. It can even perform extent - * conversion if all bios we submitted finished before we got here. - * Note that in that case iocb->private can be already set to NULL - * here. - */ - if (io_end) { - ext4_inode_aio_set(inode, NULL); - ext4_put_io_end(io_end); - /* - * When no IO was submitted ext4_end_io_dio() was not - * called so we have to put iocb's reference. - */ - if (ret <= 0 && ret != -EIOCBQUEUED && iocb->private) { - WARN_ON(iocb->private != io_end); - WARN_ON(io_end->flag & EXT4_IO_END_UNWRITTEN); - ext4_put_io_end(io_end); - iocb->private = NULL; - } - } if (ret > 0 && !overwrite && ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN)) { int err; @@ -3405,7 +3409,6 @@ static ssize_t ext4_ext_direct_IO(struct kiocb *iocb, struct iov_iter *iter, ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); } -retake_lock: if (iov_iter_rw(iter) == WRITE) inode_dio_end(inode); /* take i_mutex locking again if we do a ovewrite dio */ |
