diff options
Diffstat (limited to 'fs/ext4/inode.c')
-rw-r--r-- | fs/ext4/inode.c | 438 |
1 files changed, 301 insertions, 137 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 83bc8bf..dab84a2 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -216,7 +216,6 @@ void ext4_evict_inode(struct inode *inode) } truncate_inode_pages_final(&inode->i_data); - WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count)); goto no_delete; } @@ -228,8 +227,6 @@ void ext4_evict_inode(struct inode *inode) ext4_begin_ordered_truncate(inode, 0); truncate_inode_pages_final(&inode->i_data); - WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count)); - /* * Protect us against freezing - iput() caller didn't have to have any * protection against it @@ -458,13 +455,13 @@ static void ext4_map_blocks_es_recheck(handle_t *handle, * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping * based files * - * On success, it returns the number of blocks being mapped or allocated. - * if create==0 and the blocks are pre-allocated and unwritten block, - * the result buffer head is unmapped. If the create ==1, it will make sure - * the buffer head is mapped. + * On success, it returns the number of blocks being mapped or allocated. if + * create==0 and the blocks are pre-allocated and unwritten, the resulting @map + * is marked as unwritten. If the create == 1, it will mark @map as mapped. * * It returns 0 if plain look up failed (blocks have not been allocated), in - * that case, buffer head is unmapped + * that case, @map is returned as unmapped but we still do fill map->m_len to + * indicate the length of a hole starting at map->m_lblk. * * It returns the error in case of allocation failure. */ @@ -507,6 +504,11 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, retval = map->m_len; map->m_len = retval; } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) { + map->m_pblk = 0; + retval = es.es_len - (map->m_lblk - es.es_lblk); + if (retval > map->m_len) + retval = map->m_len; + map->m_len = retval; retval = 0; } else { BUG_ON(1); @@ -686,16 +688,39 @@ out_sem: return retval; } -/* Maximum number of blocks we map for direct IO at once. */ -#define DIO_MAX_BLOCKS 4096 +/* + * Update EXT4_MAP_FLAGS in bh->b_state. For buffer heads attached to pages + * we have to be careful as someone else may be manipulating b_state as well. + */ +static void ext4_update_bh_state(struct buffer_head *bh, unsigned long flags) +{ + unsigned long old_state; + unsigned long new_state; + + flags &= EXT4_MAP_FLAGS; + + /* Dummy buffer_head? Set non-atomically. */ + if (!bh->b_page) { + bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | flags; + return; + } + /* + * Someone else may be modifying b_state. Be careful! This is ugly but + * once we get rid of using bh as a container for mapping information + * to pass to / from get_block functions, this can go away. + */ + do { + old_state = READ_ONCE(bh->b_state); + new_state = (old_state & ~EXT4_MAP_FLAGS) | flags; + } while (unlikely( + cmpxchg(&bh->b_state, old_state, new_state) != old_state)); +} static int _ext4_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh, int flags) { - handle_t *handle = ext4_journal_current_handle(); struct ext4_map_blocks map; - int ret = 0, started = 0; - int dio_credits; + int ret = 0; if (ext4_has_inline_data(inode)) return -ERANGE; @@ -703,33 +728,14 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock, map.m_lblk = iblock; map.m_len = bh->b_size >> inode->i_blkbits; - if (flags && !handle) { - /* Direct IO write... */ - if (map.m_len > DIO_MAX_BLOCKS) - map.m_len = DIO_MAX_BLOCKS; - dio_credits = ext4_chunk_trans_blocks(inode, map.m_len); - handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, - dio_credits); - if (IS_ERR(handle)) { - ret = PTR_ERR(handle); - return ret; - } - started = 1; - } - - ret = ext4_map_blocks(handle, inode, &map, flags); + ret = ext4_map_blocks(ext4_journal_current_handle(), inode, &map, + flags); if (ret > 0) { - ext4_io_end_t *io_end = ext4_inode_aio(inode); - map_bh(bh, inode->i_sb, map.m_pblk); - bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags; - if (io_end && io_end->flag & EXT4_IO_END_UNWRITTEN) - set_buffer_defer_completion(bh); + ext4_update_bh_state(bh, map.m_flags); bh->b_size = inode->i_sb->s_blocksize * map.m_len; ret = 0; } - if (started) - ext4_journal_stop(handle); return ret; } @@ -741,6 +747,155 @@ int ext4_get_block(struct inode *inode, sector_t iblock, } /* + * Get block function used when preparing for buffered write if we require + * creating an unwritten extent if blocks haven't been allocated. The extent + * will be converted to written after the IO is complete. + */ +int ext4_get_block_unwritten(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create) +{ + ext4_debug("ext4_get_block_unwritten: inode %lu, create flag %d\n", + inode->i_ino, create); + return _ext4_get_block(inode, iblock, bh_result, + EXT4_GET_BLOCKS_IO_CREATE_EXT); +} + +/* Maximum number of blocks we map for direct IO at once. */ +#define DIO_MAX_BLOCKS 4096 + +static handle_t *start_dio_trans(struct inode *inode, + struct buffer_head *bh_result) +{ + int dio_credits; + + /* Trim mapping request to maximum we can map at once for DIO */ + if (bh_result->b_size >> inode->i_blkbits > DIO_MAX_BLOCKS) + bh_result->b_size = DIO_MAX_BLOCKS << inode->i_blkbits; + dio_credits = ext4_chunk_trans_blocks(inode, + bh_result->b_size >> inode->i_blkbits); + return ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits); +} + +/* Get block function for DIO reads and writes to inodes without extents */ +int ext4_dio_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh, int create) +{ + handle_t *handle; + int ret; + + /* We don't expect handle for direct IO */ + WARN_ON_ONCE(ext4_journal_current_handle()); + + if (create) { + handle = start_dio_trans(inode, bh); + if (IS_ERR(handle)) + return PTR_ERR(handle); + } + ret = _ext4_get_block(inode, iblock, bh, + create ? EXT4_GET_BLOCKS_CREATE : 0); + if (create) + ext4_journal_stop(handle); + return ret; +} + +/* + * 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_async(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); + + /* + * 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); + } + + 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) +{ + int ret; + + ext4_debug("ext4_dio_get_block_overwrite: 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()); + + ret = _ext4_get_block(inode, iblock, bh_result, 0); + /* + * Blocks should have been preallocated! ext4_file_write_iter() checks + * that. + */ + WARN_ON_ONCE(!buffer_mapped(bh_result) || buffer_unwritten(bh_result)); + + return ret; +} + + +/* * `handle' can be NULL if create is zero */ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode, @@ -1051,13 +1206,14 @@ retry_journal: #ifdef CONFIG_EXT4_FS_ENCRYPTION if (ext4_should_dioread_nolock(inode)) ret = ext4_block_write_begin(page, pos, len, - ext4_get_block_write); + ext4_get_block_unwritten); else ret = ext4_block_write_begin(page, pos, len, ext4_get_block); #else if (ext4_should_dioread_nolock(inode)) - ret = __block_write_begin(page, pos, len, ext4_get_block_write); + ret = __block_write_begin(page, pos, len, + ext4_get_block_unwritten); else ret = __block_write_begin(page, pos, len, ext4_get_block); #endif @@ -1685,7 +1841,7 @@ int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, return ret; map_bh(bh, inode->i_sb, map.m_pblk); - bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags; + ext4_update_bh_state(bh, map.m_flags); if (buffer_unwritten(bh)) { /* A delayed write to unwritten bh should be marked @@ -2450,6 +2606,10 @@ static int ext4_writepages(struct address_space *mapping, trace_ext4_writepages(inode, wbc); + if (dax_mapping(mapping)) + return dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, + wbc); + /* * No pages to write? This is mainly a kludge to avoid starting * a transaction for special inodes like journal inode on last iput() @@ -3056,37 +3216,6 @@ static int ext4_releasepage(struct page *page, gfp_t wait) return try_to_free_buffers(page); } -/* - * ext4_get_block used when preparing for a DIO write or buffer write. - * We allocate an uinitialized extent if blocks haven't been allocated. - * The extent will be converted to initialized after the IO is complete. - */ -int ext4_get_block_write(struct inode *inode, sector_t iblock, - struct buffer_head *bh_result, int create) -{ - ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n", - inode->i_ino, create); - return _ext4_get_block(inode, iblock, bh_result, - EXT4_GET_BLOCKS_IO_CREATE_EXT); -} - -static int ext4_get_block_overwrite(struct inode *inode, sector_t iblock, - struct buffer_head *bh_result, int create) -{ - int ret; - - ext4_debug("ext4_get_block_overwrite: inode %lu, create flag %d\n", - inode->i_ino, create); - ret = _ext4_get_block(inode, iblock, bh_result, 0); - /* - * Blocks should have been preallocated! ext4_file_write_iter() checks - * that. - */ - WARN_ON_ONCE(!buffer_mapped(bh_result)); - - return ret; -} - #ifdef CONFIG_FS_DAX int ext4_dax_mmap_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) @@ -3147,13 +3276,12 @@ out: WARN_ON_ONCE(ret == 0 && create); if (ret > 0) { map_bh(bh_result, inode->i_sb, map.m_pblk); - bh_result->b_state = (bh_result->b_state & ~EXT4_MAP_FLAGS) | - map.m_flags; /* * At least for now we have to clear BH_New so that DAX code * doesn't attempt to zero blocks again in a racy way. */ - bh_result->b_state &= ~(1 << BH_New); + map.m_flags &= ~EXT4_MAP_NEW; + ext4_update_bh_state(bh_result, map.m_flags); bh_result->b_size = map.m_len << inode->i_blkbits; ret = 0; } @@ -3161,24 +3289,32 @@ out: } #endif -static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, +static int 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) - return; + return 0; 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; + /* + * Error during AIO DIO. We cannot convert unwritten extents as the + * data was not written. Just clear the unwritten flag and drop io_end. + */ + if (size <= 0) { + ext4_clear_io_unwritten_flag(io_end); + size = 0; + } io_end->offset = offset; io_end->size = size; ext4_put_io_end(io_end); + + return 0; } /* @@ -3211,7 +3347,6 @@ 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) @@ -3236,16 +3371,17 @@ 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 @@ -3253,30 +3389,13 @@ 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; - 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); - } - - if (overwrite) { - get_block_func = ext4_get_block_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 { - get_block_func = ext4_get_block_write; + get_block_func = ext4_dio_get_block_unwritten_async; dio_flags = DIO_LOCKING; } #ifdef CONFIG_EXT4_FS_ENCRYPTION @@ -3291,27 +3410,6 @@ 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; @@ -3326,7 +3424,6 @@ 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 */ @@ -4127,7 +4224,7 @@ void ext4_set_inode_flags(struct inode *inode) new_fl |= S_NOATIME; if (flags & EXT4_DIRSYNC_FL) new_fl |= S_DIRSYNC; - if (test_opt(inode->i_sb, DAX)) + if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) new_fl |= S_DAX; inode_set_flags(inode, new_fl, S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX); @@ -5229,6 +5326,8 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) might_sleep(); trace_ext4_mark_inode_dirty(inode, _RET_IP_); err = ext4_reserve_inode_write(handle, inode, &iloc); + if (err) + return err; if (ext4_handle_valid(handle) && EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize && !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) { @@ -5259,9 +5358,7 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) } } } - if (!err) - err = ext4_mark_iloc_dirty(handle, inode, &iloc); - return err; + return ext4_mark_iloc_dirty(handle, inode, &iloc); } /* @@ -5470,7 +5567,7 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) unlock_page(page); /* OK, we need to fill the hole... */ if (ext4_should_dioread_nolock(inode)) - get_block = ext4_get_block_write; + get_block = ext4_get_block_unwritten; else get_block = ext4_get_block; retry_alloc: @@ -5513,3 +5610,70 @@ int ext4_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) return err; } + +/* + * Find the first extent at or after @lblk in an inode that is not a hole. + * Search for @map_len blocks at most. The extent is returned in @result. + * + * The function returns 1 if we found an extent. The function returns 0 in + * case there is no extent at or after @lblk and in that case also sets + * @result->es_len to 0. In case of error, the error code is returned. + */ +int ext4_get_next_extent(struct inode *inode, ext4_lblk_t lblk, + unsigned int map_len, struct extent_status *result) +{ + struct ext4_map_blocks map; + struct extent_status es = {}; + int ret; + + map.m_lblk = lblk; + map.m_len = map_len; + + /* + * For non-extent based files this loop may iterate several times since + * we do not determine full hole size. + */ + while (map.m_len > 0) { + ret = ext4_map_blocks(NULL, inode, &map, 0); + if (ret < 0) + return ret; + /* There's extent covering m_lblk? Just return it. */ + if (ret > 0) { + int status; + + ext4_es_store_pblock(result, map.m_pblk); + result->es_lblk = map.m_lblk; + result->es_len = map.m_len; + if (map.m_flags & EXT4_MAP_UNWRITTEN) + status = EXTENT_STATUS_UNWRITTEN; + else + status = EXTENT_STATUS_WRITTEN; + ext4_es_store_status(result, status); + return 1; + } + ext4_es_find_delayed_extent_range(inode, map.m_lblk, + map.m_lblk + map.m_len - 1, + &es); + /* Is delalloc data before next block in extent tree? */ + if (es.es_len && es.es_lblk < map.m_lblk + map.m_len) { + ext4_lblk_t offset = 0; + + if (es.es_lblk < lblk) + offset = lblk - es.es_lblk; + result->es_lblk = es.es_lblk + offset; + ext4_es_store_pblock(result, + ext4_es_pblock(&es) + offset); + result->es_len = es.es_len - offset; + ext4_es_store_status(result, ext4_es_status(&es)); + + return 1; + } + /* There's a hole at m_lblk, advance us after it */ + map.m_lblk += map.m_len; + map_len -= map.m_len; + map.m_len = map_len; + cond_resched(); + } + result->es_len = 0; + return 0; +} |