From ffbd517d5a8c8e93ddd11046434fb029f3df73aa Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 20 Apr 2009 15:50:09 -0400 Subject: Btrfs: use WRITE_SYNC for synchronous writes Part of reducing fsync/O_SYNC/O_DIRECT latencies is using WRITE_SYNC for writes we plan on waiting on in the near future. This patch mirrors recent changes in other filesystems and the generic code to use WRITE_SYNC when WB_SYNC_ALL is passed and to use WRITE_SYNC for other latency critical writes. Btrfs uses async worker threads for checksumming before the write is done, and then again to actually submit the bios. The bio submission code just runs a per-device list of bios that need to be sent down the pipe. This list is split into low priority and high priority lists so the WRITE_SYNC IO happens first. Signed-off-by: Chris Mason --- fs/btrfs/volumes.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/volumes.h') diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 2185de72ff7d..5836327ba5dd 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -23,13 +23,22 @@ #include "async-thread.h" struct buffer_head; +struct btrfs_pending_bios { + struct bio *head; + struct bio *tail; +}; + struct btrfs_device { struct list_head dev_list; struct list_head dev_alloc_list; struct btrfs_fs_devices *fs_devices; struct btrfs_root *dev_root; - struct bio *pending_bios; - struct bio *pending_bio_tail; + + /* regular prio bios */ + struct btrfs_pending_bios pending_bios; + /* WRITE_SYNC bios */ + struct btrfs_pending_bios pending_sync_bios; + int running_pending; u64 generation; -- cgit v1.2.3 From d6397baee468809ef311e763dfc6e9f73418f8a6 Mon Sep 17 00:00:00 2001 From: Chris Ball Date: Mon, 27 Apr 2009 07:29:03 -0400 Subject: Btrfs: When shrinking, only update disk size on success Previously, we updated a device's size prior to attempting a shrink operation. This patch moves the device resizing logic to only happen if the shrink completes successfully. In the process, it introduces a new field to btrfs_device -- disk_total_bytes -- to track the on-disk size. Signed-off-by: Chris Ball Signed-off-by: Chris Mason --- fs/btrfs/volumes.c | 35 ++++++++++++++++++++++++----------- fs/btrfs/volumes.h | 3 +++ 2 files changed, 27 insertions(+), 11 deletions(-) (limited to 'fs/btrfs/volumes.h') diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index e53835b88594..5f01dad4b696 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1543,7 +1543,7 @@ static noinline int btrfs_update_device(struct btrfs_trans_handle *trans, btrfs_set_device_io_align(leaf, dev_item, device->io_align); btrfs_set_device_io_width(leaf, dev_item, device->io_width); btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); - btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes); + btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes); btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); btrfs_mark_buffer_dirty(leaf); @@ -1940,14 +1940,6 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) device->total_bytes = new_size; if (device->writeable) device->fs_devices->total_rw_bytes -= diff; - ret = btrfs_update_device(trans, device); - if (ret) { - unlock_chunks(root); - btrfs_end_transaction(trans, root); - goto done; - } - WARN_ON(diff > old_total); - btrfs_set_super_total_bytes(super_copy, old_total - diff); unlock_chunks(root); btrfs_end_transaction(trans, root); @@ -1979,7 +1971,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) length = btrfs_dev_extent_length(l, dev_extent); if (key.offset + length <= new_size) - goto done; + break; chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent); chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent); @@ -1992,6 +1984,26 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) goto done; } + /* Shrinking succeeded, else we would be at "done". */ + trans = btrfs_start_transaction(root, 1); + if (!trans) { + ret = -ENOMEM; + goto done; + } + lock_chunks(root); + + device->disk_total_bytes = new_size; + /* Now btrfs_update_device() will change the on-disk size. */ + ret = btrfs_update_device(trans, device); + if (ret) { + unlock_chunks(root); + btrfs_end_transaction(trans, root); + goto done; + } + WARN_ON(diff > old_total); + btrfs_set_super_total_bytes(super_copy, old_total - diff); + unlock_chunks(root); + btrfs_end_transaction(trans, root); done: btrfs_free_path(path); return ret; @@ -3076,7 +3088,8 @@ static int fill_device_from_item(struct extent_buffer *leaf, unsigned long ptr; device->devid = btrfs_device_id(leaf, dev_item); - device->total_bytes = btrfs_device_total_bytes(leaf, dev_item); + device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item); + device->total_bytes = device->disk_total_bytes; device->bytes_used = btrfs_device_bytes_used(leaf, dev_item); device->type = btrfs_device_type(leaf, dev_item); device->io_align = btrfs_device_io_align(leaf, dev_item); diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 5836327ba5dd..5c3ff6d02fd7 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -61,6 +61,9 @@ struct btrfs_device { /* size of the device */ u64 total_bytes; + /* size of the disk */ + u64 disk_total_bytes; + /* bytes used */ u64 bytes_used; -- cgit v1.2.3