From 7eaebe7d503c3ef240ac7b3efc5433fe647c0298 Mon Sep 17 00:00:00 2001 From: Huang Weiyi Date: Wed, 21 Jan 2009 10:49:16 -0500 Subject: Btrfs: removed unused #include 's Removed unused #include 's in btrfs Signed-off-by: Huang Weiyi Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 81a313874ae..37e12f62039 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -16,7 +16,6 @@ * Boston, MA 021110-1307, USA. */ -#include #include #include #include -- cgit v1.2.3-70-g09d2 From 57506d50ed6db7b0e7ddc9845e86e81f140983d5 Mon Sep 17 00:00:00 2001 From: Qinghuang Feng Date: Wed, 21 Jan 2009 10:49:16 -0500 Subject: Btrfs: check return value for kthread_run() correctly kthread_run() returns the kthread or ERR_PTR(-ENOMEM), not NULL. Signed-off-by: Qinghuang Feng Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 37e12f62039..0d8ccd625ba 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1739,13 +1739,13 @@ struct btrfs_root *open_ctree(struct super_block *sb, fs_info->system_alloc_profile = fs_info->metadata_alloc_profile; fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root, "btrfs-cleaner"); - if (!fs_info->cleaner_kthread) + if (IS_ERR(fs_info->cleaner_kthread)) goto fail_csum_root; fs_info->transaction_kthread = kthread_run(transaction_kthread, tree_root, "btrfs-transaction"); - if (!fs_info->transaction_kthread) + if (IS_ERR(fs_info->transaction_kthread)) goto fail_cleaner; if (btrfs_super_log_root(disk_super) != 0) { -- cgit v1.2.3-70-g09d2 From c6e308713a47527f88a277ee95b7c5d1db80f77b Mon Sep 17 00:00:00 2001 From: Qinghuang Feng Date: Wed, 21 Jan 2009 10:59:08 -0500 Subject: Btrfs: simplify iteration codes Merge list_for_each* and list_entry to list_for_each_entry* Signed-off-by: Qinghuang Feng Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 15 ++++----------- fs/btrfs/extent-tree.c | 8 ++------ fs/btrfs/inode.c | 5 ++--- fs/btrfs/ordered-data.c | 4 +--- fs/btrfs/transaction.c | 4 +--- fs/btrfs/volumes.c | 35 +++++++++-------------------------- 6 files changed, 19 insertions(+), 52 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 0d8ccd625ba..26a18779e84 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1135,7 +1135,6 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits) { struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data; int ret = 0; - struct list_head *cur; struct btrfs_device *device; struct backing_dev_info *bdi; #if 0 @@ -1143,8 +1142,7 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits) btrfs_congested_async(info, 0)) return 1; #endif - list_for_each(cur, &info->fs_devices->devices) { - device = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(device, &info->fs_devices->devices, dev_list) { if (!device->bdev) continue; bdi = blk_get_backing_dev_info(device->bdev); @@ -1162,13 +1160,11 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits) */ static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page) { - struct list_head *cur; struct btrfs_device *device; struct btrfs_fs_info *info; info = (struct btrfs_fs_info *)bdi->unplug_io_data; - list_for_each(cur, &info->fs_devices->devices) { - device = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(device, &info->fs_devices->devices, dev_list) { if (!device->bdev) continue; @@ -1994,7 +1990,6 @@ static int write_dev_supers(struct btrfs_device *device, int write_all_supers(struct btrfs_root *root, int max_mirrors) { - struct list_head *cur; struct list_head *head = &root->fs_info->fs_devices->devices; struct btrfs_device *dev; struct btrfs_super_block *sb; @@ -2010,8 +2005,7 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors) sb = &root->fs_info->super_for_commit; dev_item = &sb->dev_item; - list_for_each(cur, head) { - dev = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(dev, head, dev_list) { if (!dev->bdev) { total_errors++; continue; @@ -2044,8 +2038,7 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors) } total_errors = 0; - list_for_each(cur, head) { - dev = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(dev, head, dev_list) { if (!dev->bdev) continue; if (!dev->in_fs_metadata || !dev->writeable) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index cdc961e7556..a4e36c38b81 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -325,10 +325,8 @@ static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info, u64 flags) { struct list_head *head = &info->space_info; - struct list_head *cur; struct btrfs_space_info *found; - list_for_each(cur, head) { - found = list_entry(cur, struct btrfs_space_info, list); + list_for_each_entry(found, head, list) { if (found->flags == flags) return found; } @@ -3013,7 +3011,6 @@ loop_check: static void dump_space_info(struct btrfs_space_info *info, u64 bytes) { struct btrfs_block_group_cache *cache; - struct list_head *l; printk(KERN_INFO "space_info has %llu free, is %sfull\n", (unsigned long long)(info->total_bytes - info->bytes_used - @@ -3021,8 +3018,7 @@ static void dump_space_info(struct btrfs_space_info *info, u64 bytes) (info->full) ? "" : "not "); down_read(&info->groups_sem); - list_for_each(l, &info->block_groups) { - cache = list_entry(l, struct btrfs_block_group_cache, list); + list_for_each_entry(cache, &info->block_groups, list) { spin_lock(&cache->lock); printk(KERN_INFO "block group %llu has %llu bytes, %llu used " "%llu pinned %llu reserved\n", diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 44dbd550c4b..45cf03ee1bc 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1323,12 +1323,11 @@ static noinline int add_pending_csums(struct btrfs_trans_handle *trans, struct inode *inode, u64 file_offset, struct list_head *list) { - struct list_head *cur; struct btrfs_ordered_sum *sum; btrfs_set_trans_block_group(trans, inode); - list_for_each(cur, list) { - sum = list_entry(cur, struct btrfs_ordered_sum, list); + + list_for_each_entry(sum, list, list) { btrfs_csum_file_blocks(trans, BTRFS_I(inode)->root->fs_info->csum_root, sum); } diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c index a2094017027..77c2411a5f0 100644 --- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -613,7 +613,6 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, struct btrfs_sector_sum *sector_sums; struct btrfs_ordered_extent *ordered; struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; - struct list_head *cur; unsigned long num_sectors; unsigned long i; u32 sectorsize = BTRFS_I(inode)->root->sectorsize; @@ -624,8 +623,7 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, return 1; mutex_lock(&tree->mutex); - list_for_each_prev(cur, &ordered->list) { - ordered_sum = list_entry(cur, struct btrfs_ordered_sum, list); + list_for_each_entry_reverse(ordered_sum, &ordered->list, list) { if (disk_bytenr >= ordered_sum->bytenr) { num_sectors = ordered_sum->len / sectorsize; sector_sums = ordered_sum->sums; diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 8a08f944334..919172de5c9 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -852,11 +852,9 @@ static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans, { struct btrfs_pending_snapshot *pending; struct list_head *head = &trans->transaction->pending_snapshots; - struct list_head *cur; int ret; - list_for_each(cur, head) { - pending = list_entry(cur, struct btrfs_pending_snapshot, list); + list_for_each_entry(pending, head, list) { ret = create_pending_snapshot(trans, fs_info, pending); BUG_ON(ret); } diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 397c8db1bc2..fd0bedb07a6 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -103,10 +103,8 @@ static noinline struct btrfs_device *__find_device(struct list_head *head, u64 devid, u8 *uuid) { struct btrfs_device *dev; - struct list_head *cur; - list_for_each(cur, head) { - dev = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(dev, head, dev_list) { if (dev->devid == devid && (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) { return dev; @@ -117,11 +115,9 @@ static noinline struct btrfs_device *__find_device(struct list_head *head, static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid) { - struct list_head *cur; struct btrfs_fs_devices *fs_devices; - list_for_each(cur, &fs_uuids) { - fs_devices = list_entry(cur, struct btrfs_fs_devices, list); + list_for_each_entry(fs_devices, &fs_uuids, list) { if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0) return fs_devices; } @@ -344,14 +340,11 @@ error: int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices) { - struct list_head *tmp; - struct list_head *cur; - struct btrfs_device *device; + struct btrfs_device *device, *next; mutex_lock(&uuid_mutex); again: - list_for_each_safe(cur, tmp, &fs_devices->devices) { - device = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { if (device->in_fs_metadata) continue; @@ -382,14 +375,12 @@ again: static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices) { - struct list_head *cur; struct btrfs_device *device; if (--fs_devices->opened > 0) return 0; - list_for_each(cur, &fs_devices->devices) { - device = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(device, &fs_devices->devices, dev_list) { if (device->bdev) { close_bdev_exclusive(device->bdev, device->mode); fs_devices->open_devices--; @@ -438,7 +429,6 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, { struct block_device *bdev; struct list_head *head = &fs_devices->devices; - struct list_head *cur; struct btrfs_device *device; struct block_device *latest_bdev = NULL; struct buffer_head *bh; @@ -449,8 +439,7 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int seeding = 1; int ret = 0; - list_for_each(cur, head) { - device = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(device, head, dev_list) { if (device->bdev) continue; if (!device->name) @@ -1016,14 +1005,12 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) } if (strcmp(device_path, "missing") == 0) { - struct list_head *cur; struct list_head *devices; struct btrfs_device *tmp; device = NULL; devices = &root->fs_info->fs_devices->devices; - list_for_each(cur, devices) { - tmp = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(tmp, devices, dev_list) { if (tmp->in_fs_metadata && !tmp->bdev) { device = tmp; break; @@ -1279,7 +1266,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) struct btrfs_trans_handle *trans; struct btrfs_device *device; struct block_device *bdev; - struct list_head *cur; struct list_head *devices; struct super_block *sb = root->fs_info->sb; u64 total_bytes; @@ -1303,8 +1289,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) mutex_lock(&root->fs_info->volume_mutex); devices = &root->fs_info->fs_devices->devices; - list_for_each(cur, devices) { - device = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(device, devices, dev_list) { if (device->bdev == bdev) { ret = -EEXIST; goto error; @@ -1703,7 +1688,6 @@ static u64 div_factor(u64 num, int factor) int btrfs_balance(struct btrfs_root *dev_root) { int ret; - struct list_head *cur; struct list_head *devices = &dev_root->fs_info->fs_devices->devices; struct btrfs_device *device; u64 old_size; @@ -1722,8 +1706,7 @@ int btrfs_balance(struct btrfs_root *dev_root) dev_root = dev_root->fs_info->dev_root; /* step one make some room on all the devices */ - list_for_each(cur, devices) { - device = list_entry(cur, struct btrfs_device, dev_list); + list_for_each_entry(device, devices, dev_list) { old_size = device->total_bytes; size_to_free = div_factor(old_size, 1); size_to_free = min(size_to_free, (u64)1 * 1024 * 1024); -- cgit v1.2.3-70-g09d2 From 7e6628544abad773222d8b177f738ac2db1859de Mon Sep 17 00:00:00 2001 From: Qinghuang Feng Date: Wed, 21 Jan 2009 10:49:16 -0500 Subject: Btrfs: open_ctree() error handling can oops on fs_info a bug in open_ctree: struct btrfs_root *open_ctree(..) { .... if (!extent_root || !tree_root || !fs_info || !chunk_root || !dev_root || !csum_root) { err = -ENOMEM; goto fail; //When code flow goes to "fail", fs_info may be NULL or uninitialized. } .... fail: btrfs_close_devices(fs_info->fs_devices);// ! btrfs_mapping_tree_free(&fs_info->mapping_tree);// ! kfree(extent_root); kfree(tree_root); bdi_destroy(&fs_info->bdi);// ! ... ) Signed-off-by: Qinghuang Feng Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 26a18779e84..3cf17257f89 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1823,13 +1823,14 @@ fail_sb_buffer: fail_iput: invalidate_inode_pages2(fs_info->btree_inode->i_mapping); iput(fs_info->btree_inode); -fail: + btrfs_close_devices(fs_info->fs_devices); btrfs_mapping_tree_free(&fs_info->mapping_tree); + bdi_destroy(&fs_info->bdi); +fail: kfree(extent_root); kfree(tree_root); - bdi_destroy(&fs_info->bdi); kfree(fs_info); kfree(chunk_root); kfree(dev_root); -- cgit v1.2.3-70-g09d2 From 7237f1833601dcc435a64176c2c347ec4bd959f9 Mon Sep 17 00:00:00 2001 From: Yan Zheng Date: Wed, 21 Jan 2009 12:54:03 -0500 Subject: Btrfs: fix tree logs parallel sync To improve performance, btrfs_sync_log merges tree log sync requests. But it wrongly merges sync requests for different tree logs. If multiple tree logs are synced at the same time, only one of them actually gets synced. This patch has following changes to fix the bug: Move most tree log related fields in btrfs_fs_info to btrfs_root. This allows merging sync requests separately for each tree log. Don't insert root item into the log root tree immediately after log tree is allocated. Root item for log tree is inserted when log tree get synced for the first time. This allows syncing the log root tree without first syncing all log trees. At tree-log sync, btrfs_sync_log first sync the log tree; then updates corresponding root item in the log root tree; sync the log root tree; then update the super block. Signed-off-by: Yan Zheng --- fs/btrfs/ctree.h | 13 +- fs/btrfs/disk-io.c | 79 +++++++++-- fs/btrfs/disk-io.h | 2 + fs/btrfs/extent-tree.c | 10 +- fs/btrfs/file.c | 4 +- fs/btrfs/tree-log.c | 350 +++++++++++++++++++++++-------------------------- 6 files changed, 248 insertions(+), 210 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index e1fec636f37..de103a8a815 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -695,9 +695,7 @@ struct btrfs_fs_info { struct btrfs_transaction *running_transaction; wait_queue_head_t transaction_throttle; wait_queue_head_t transaction_wait; - wait_queue_head_t async_submit_wait; - wait_queue_head_t tree_log_wait; struct btrfs_super_block super_copy; struct btrfs_super_block super_for_commit; @@ -724,10 +722,6 @@ struct btrfs_fs_info { atomic_t async_submit_draining; atomic_t nr_async_bios; atomic_t async_delalloc_pages; - atomic_t tree_log_writers; - atomic_t tree_log_commit; - unsigned long tree_log_batch; - u64 tree_log_transid; /* * this is used by the balancing code to wait for all the pending @@ -827,7 +821,14 @@ struct btrfs_root { struct kobject root_kobj; struct completion kobj_unregister; struct mutex objectid_mutex; + struct mutex log_mutex; + wait_queue_head_t log_writer_wait; + wait_queue_head_t log_commit_wait[2]; + atomic_t log_writers; + atomic_t log_commit[2]; + unsigned long log_transid; + unsigned long log_batch; u64 objectid; u64 last_trans; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 3cf17257f89..7feac5a475e 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -849,6 +849,14 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize, spin_lock_init(&root->list_lock); mutex_init(&root->objectid_mutex); mutex_init(&root->log_mutex); + init_waitqueue_head(&root->log_writer_wait); + init_waitqueue_head(&root->log_commit_wait[0]); + init_waitqueue_head(&root->log_commit_wait[1]); + atomic_set(&root->log_commit[0], 0); + atomic_set(&root->log_commit[1], 0); + atomic_set(&root->log_writers, 0); + root->log_batch = 0; + root->log_transid = 0; extent_io_tree_init(&root->dirty_log_pages, fs_info->btree_inode->i_mapping, GFP_NOFS); @@ -933,15 +941,16 @@ int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, return 0; } -int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, - struct btrfs_fs_info *fs_info) +static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info) { struct btrfs_root *root; struct btrfs_root *tree_root = fs_info->tree_root; + struct extent_buffer *leaf; root = kzalloc(sizeof(*root), GFP_NOFS); if (!root) - return -ENOMEM; + return ERR_PTR(-ENOMEM); __setup_root(tree_root->nodesize, tree_root->leafsize, tree_root->sectorsize, tree_root->stripesize, @@ -950,12 +959,23 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID; root->root_key.type = BTRFS_ROOT_ITEM_KEY; root->root_key.offset = BTRFS_TREE_LOG_OBJECTID; + /* + * log trees do not get reference counted because they go away + * before a real commit is actually done. They do store pointers + * to file data extents, and those reference counts still get + * updated (along with back refs to the log tree). + */ root->ref_cows = 0; - root->node = btrfs_alloc_free_block(trans, root, root->leafsize, - 0, BTRFS_TREE_LOG_OBJECTID, - trans->transid, 0, 0, 0); + leaf = btrfs_alloc_free_block(trans, root, root->leafsize, + 0, BTRFS_TREE_LOG_OBJECTID, + trans->transid, 0, 0, 0); + if (IS_ERR(leaf)) { + kfree(root); + return ERR_CAST(leaf); + } + root->node = leaf; btrfs_set_header_nritems(root->node, 0); btrfs_set_header_level(root->node, 0); btrfs_set_header_bytenr(root->node, root->node->start); @@ -967,7 +987,48 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, BTRFS_FSID_SIZE); btrfs_mark_buffer_dirty(root->node); btrfs_tree_unlock(root->node); - fs_info->log_root_tree = root; + return root; +} + +int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *log_root; + + log_root = alloc_log_tree(trans, fs_info); + if (IS_ERR(log_root)) + return PTR_ERR(log_root); + WARN_ON(fs_info->log_root_tree); + fs_info->log_root_tree = log_root; + return 0; +} + +int btrfs_add_log_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_root *log_root; + struct btrfs_inode_item *inode_item; + + log_root = alloc_log_tree(trans, root->fs_info); + if (IS_ERR(log_root)) + return PTR_ERR(log_root); + + log_root->last_trans = trans->transid; + log_root->root_key.offset = root->root_key.objectid; + + inode_item = &log_root->root_item.inode; + inode_item->generation = cpu_to_le64(1); + inode_item->size = cpu_to_le64(3); + inode_item->nlink = cpu_to_le32(1); + inode_item->nbytes = cpu_to_le64(root->leafsize); + inode_item->mode = cpu_to_le32(S_IFDIR | 0755); + + btrfs_set_root_bytenr(&log_root->root_item, log_root->node->start); + btrfs_set_root_generation(&log_root->root_item, trans->transid); + + WARN_ON(root->log_root); + root->log_root = log_root; + root->log_transid = 0; return 0; } @@ -1530,10 +1591,6 @@ struct btrfs_root *open_ctree(struct super_block *sb, init_waitqueue_head(&fs_info->transaction_throttle); init_waitqueue_head(&fs_info->transaction_wait); init_waitqueue_head(&fs_info->async_submit_wait); - init_waitqueue_head(&fs_info->tree_log_wait); - atomic_set(&fs_info->tree_log_commit, 0); - atomic_set(&fs_info->tree_log_writers, 0); - fs_info->tree_log_transid = 0; __setup_root(4096, 4096, 4096, 4096, tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID); diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index c0ff404c31b..494a56eb298 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -98,5 +98,7 @@ int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info); int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info); +int btrfs_add_log_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root); int btree_lock_page_hook(struct page *page); #endif diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 1d7f043152b..3b26f098094 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2698,13 +2698,9 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans, /* if metadata always pin */ if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) { if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { - struct btrfs_block_group_cache *cache; - - /* btrfs_free_reserved_extent */ - cache = btrfs_lookup_block_group(root->fs_info, bytenr); - BUG_ON(!cache); - btrfs_add_free_space(cache, bytenr, num_bytes); - put_block_group(cache); + mutex_lock(&root->fs_info->pinned_mutex); + btrfs_update_pinned_extents(root, bytenr, num_bytes, 1); + mutex_unlock(&root->fs_info->pinned_mutex); update_reserved_extents(root, bytenr, num_bytes, 0); return 0; } diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index fbcbf43f511..3e8023efaff 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1214,10 +1214,10 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync) } mutex_unlock(&root->fs_info->trans_mutex); - root->fs_info->tree_log_batch++; + root->log_batch++; filemap_fdatawrite(inode->i_mapping); btrfs_wait_ordered_range(inode, 0, (u64)-1); - root->fs_info->tree_log_batch++; + root->log_batch++; /* * ok we haven't committed the transaction yet, lets do a commit diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index d81cda2e077..4f26f3ed0c8 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -77,104 +77,6 @@ static int link_to_fixup_dir(struct btrfs_trans_handle *trans, * and once to do all the other items. */ -/* - * btrfs_add_log_tree adds a new per-subvolume log tree into the - * tree of log tree roots. This must be called with a tree log transaction - * running (see start_log_trans). - */ -static int btrfs_add_log_tree(struct btrfs_trans_handle *trans, - struct btrfs_root *root) -{ - struct btrfs_key key; - struct btrfs_root_item root_item; - struct btrfs_inode_item *inode_item; - struct extent_buffer *leaf; - struct btrfs_root *new_root = root; - int ret; - u64 objectid = root->root_key.objectid; - - leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, - BTRFS_TREE_LOG_OBJECTID, - trans->transid, 0, 0, 0); - if (IS_ERR(leaf)) { - ret = PTR_ERR(leaf); - return ret; - } - - btrfs_set_header_nritems(leaf, 0); - btrfs_set_header_level(leaf, 0); - btrfs_set_header_bytenr(leaf, leaf->start); - btrfs_set_header_generation(leaf, trans->transid); - btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID); - - write_extent_buffer(leaf, root->fs_info->fsid, - (unsigned long)btrfs_header_fsid(leaf), - BTRFS_FSID_SIZE); - btrfs_mark_buffer_dirty(leaf); - - inode_item = &root_item.inode; - memset(inode_item, 0, sizeof(*inode_item)); - inode_item->generation = cpu_to_le64(1); - inode_item->size = cpu_to_le64(3); - inode_item->nlink = cpu_to_le32(1); - inode_item->nbytes = cpu_to_le64(root->leafsize); - inode_item->mode = cpu_to_le32(S_IFDIR | 0755); - - btrfs_set_root_bytenr(&root_item, leaf->start); - btrfs_set_root_generation(&root_item, trans->transid); - btrfs_set_root_level(&root_item, 0); - btrfs_set_root_refs(&root_item, 0); - btrfs_set_root_used(&root_item, 0); - - memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); - root_item.drop_level = 0; - - btrfs_tree_unlock(leaf); - free_extent_buffer(leaf); - leaf = NULL; - - btrfs_set_root_dirid(&root_item, 0); - - key.objectid = BTRFS_TREE_LOG_OBJECTID; - key.offset = objectid; - btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); - ret = btrfs_insert_root(trans, root->fs_info->log_root_tree, &key, - &root_item); - if (ret) - goto fail; - - new_root = btrfs_read_fs_root_no_radix(root->fs_info->log_root_tree, - &key); - BUG_ON(!new_root); - - WARN_ON(root->log_root); - root->log_root = new_root; - - /* - * log trees do not get reference counted because they go away - * before a real commit is actually done. They do store pointers - * to file data extents, and those reference counts still get - * updated (along with back refs to the log tree). - */ - new_root->ref_cows = 0; - new_root->last_trans = trans->transid; - - /* - * we need to make sure the root block for this new tree - * is marked as dirty in the dirty_log_pages tree. This - * is how it gets flushed down to disk at tree log commit time. - * - * the tree logging mutex keeps others from coming in and changing - * the new_root->node, so we can safely access it here - */ - set_extent_dirty(&new_root->dirty_log_pages, new_root->node->start, - new_root->node->start + new_root->node->len - 1, - GFP_NOFS); - -fail: - return ret; -} - /* * start a sub transaction and setup the log tree * this increments the log tree writer count to make the people @@ -184,6 +86,14 @@ static int start_log_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root) { int ret; + + mutex_lock(&root->log_mutex); + if (root->log_root) { + root->log_batch++; + atomic_inc(&root->log_writers); + mutex_unlock(&root->log_mutex); + return 0; + } mutex_lock(&root->fs_info->tree_log_mutex); if (!root->fs_info->log_root_tree) { ret = btrfs_init_log_root_tree(trans, root->fs_info); @@ -193,9 +103,10 @@ static int start_log_trans(struct btrfs_trans_handle *trans, ret = btrfs_add_log_tree(trans, root); BUG_ON(ret); } - atomic_inc(&root->fs_info->tree_log_writers); - root->fs_info->tree_log_batch++; mutex_unlock(&root->fs_info->tree_log_mutex); + root->log_batch++; + atomic_inc(&root->log_writers); + mutex_unlock(&root->log_mutex); return 0; } @@ -212,13 +123,12 @@ static int join_running_log_trans(struct btrfs_root *root) if (!root->log_root) return -ENOENT; - mutex_lock(&root->fs_info->tree_log_mutex); + mutex_lock(&root->log_mutex); if (root->log_root) { ret = 0; - atomic_inc(&root->fs_info->tree_log_writers); - root->fs_info->tree_log_batch++; + atomic_inc(&root->log_writers); } - mutex_unlock(&root->fs_info->tree_log_mutex); + mutex_unlock(&root->log_mutex); return ret; } @@ -228,10 +138,11 @@ static int join_running_log_trans(struct btrfs_root *root) */ static int end_log_trans(struct btrfs_root *root) { - atomic_dec(&root->fs_info->tree_log_writers); - smp_mb(); - if (waitqueue_active(&root->fs_info->tree_log_wait)) - wake_up(&root->fs_info->tree_log_wait); + if (atomic_dec_and_test(&root->log_writers)) { + smp_mb(); + if (waitqueue_active(&root->log_writer_wait)) + wake_up(&root->log_writer_wait); + } return 0; } @@ -1902,26 +1813,65 @@ static int walk_log_tree(struct btrfs_trans_handle *trans, } } btrfs_free_path(path); - if (wc->free) - free_extent_buffer(log->node); return ret; } -static int wait_log_commit(struct btrfs_root *log) +/* + * helper function to update the item for a given subvolumes log root + * in the tree of log roots + */ +static int update_log_root(struct btrfs_trans_handle *trans, + struct btrfs_root *log) +{ + int ret; + + if (log->log_transid == 1) { + /* insert root item on the first sync */ + ret = btrfs_insert_root(trans, log->fs_info->log_root_tree, + &log->root_key, &log->root_item); + } else { + ret = btrfs_update_root(trans, log->fs_info->log_root_tree, + &log->root_key, &log->root_item); + } + return ret; +} + +static int wait_log_commit(struct btrfs_root *root, unsigned long transid) { DEFINE_WAIT(wait); - u64 transid = log->fs_info->tree_log_transid; + int index = transid % 2; + /* + * we only allow two pending log transactions at a time, + * so we know that if ours is more than 2 older than the + * current transaction, we're done + */ do { - prepare_to_wait(&log->fs_info->tree_log_wait, &wait, - TASK_UNINTERRUPTIBLE); - mutex_unlock(&log->fs_info->tree_log_mutex); - if (atomic_read(&log->fs_info->tree_log_commit)) + prepare_to_wait(&root->log_commit_wait[index], + &wait, TASK_UNINTERRUPTIBLE); + mutex_unlock(&root->log_mutex); + if (root->log_transid < transid + 2 && + atomic_read(&root->log_commit[index])) schedule(); - finish_wait(&log->fs_info->tree_log_wait, &wait); - mutex_lock(&log->fs_info->tree_log_mutex); - } while (transid == log->fs_info->tree_log_transid && - atomic_read(&log->fs_info->tree_log_commit)); + finish_wait(&root->log_commit_wait[index], &wait); + mutex_lock(&root->log_mutex); + } while (root->log_transid < transid + 2 && + atomic_read(&root->log_commit[index])); + return 0; +} + +static int wait_for_writer(struct btrfs_root *root) +{ + DEFINE_WAIT(wait); + while (atomic_read(&root->log_writers)) { + prepare_to_wait(&root->log_writer_wait, + &wait, TASK_UNINTERRUPTIBLE); + mutex_unlock(&root->log_mutex); + if (atomic_read(&root->log_writers)) + schedule(); + mutex_lock(&root->log_mutex); + finish_wait(&root->log_writer_wait, &wait); + } return 0; } @@ -1933,57 +1883,114 @@ static int wait_log_commit(struct btrfs_root *log) int btrfs_sync_log(struct btrfs_trans_handle *trans, struct btrfs_root *root) { + int index1; + int index2; int ret; - unsigned long batch; struct btrfs_root *log = root->log_root; + struct btrfs_root *log_root_tree = root->fs_info->log_root_tree; - mutex_lock(&log->fs_info->tree_log_mutex); - if (atomic_read(&log->fs_info->tree_log_commit)) { - wait_log_commit(log); - goto out; + mutex_lock(&root->log_mutex); + index1 = root->log_transid % 2; + if (atomic_read(&root->log_commit[index1])) { + wait_log_commit(root, root->log_transid); + mutex_unlock(&root->log_mutex); + return 0; } - atomic_set(&log->fs_info->tree_log_commit, 1); + atomic_set(&root->log_commit[index1], 1); + + /* wait for previous tree log sync to complete */ + if (atomic_read(&root->log_commit[(index1 + 1) % 2])) + wait_log_commit(root, root->log_transid - 1); while (1) { - batch = log->fs_info->tree_log_batch; - mutex_unlock(&log->fs_info->tree_log_mutex); + unsigned long batch = root->log_batch; + mutex_unlock(&root->log_mutex); schedule_timeout_uninterruptible(1); - mutex_lock(&log->fs_info->tree_log_mutex); - - while (atomic_read(&log->fs_info->tree_log_writers)) { - DEFINE_WAIT(wait); - prepare_to_wait(&log->fs_info->tree_log_wait, &wait, - TASK_UNINTERRUPTIBLE); - mutex_unlock(&log->fs_info->tree_log_mutex); - if (atomic_read(&log->fs_info->tree_log_writers)) - schedule(); - mutex_lock(&log->fs_info->tree_log_mutex); - finish_wait(&log->fs_info->tree_log_wait, &wait); - } - if (batch == log->fs_info->tree_log_batch) + mutex_lock(&root->log_mutex); + wait_for_writer(root); + if (batch == root->log_batch) break; } ret = btrfs_write_and_wait_marked_extents(log, &log->dirty_log_pages); BUG_ON(ret); - ret = btrfs_write_and_wait_marked_extents(root->fs_info->log_root_tree, - &root->fs_info->log_root_tree->dirty_log_pages); + + btrfs_set_root_bytenr(&log->root_item, log->node->start); + btrfs_set_root_generation(&log->root_item, trans->transid); + btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node)); + + root->log_batch = 0; + root->log_transid++; + log->log_transid = root->log_transid; + smp_mb(); + /* + * log tree has been flushed to disk, new modifications of + * the log will be written to new positions. so it's safe to + * allow log writers to go in. + */ + mutex_unlock(&root->log_mutex); + + mutex_lock(&log_root_tree->log_mutex); + log_root_tree->log_batch++; + atomic_inc(&log_root_tree->log_writers); + mutex_unlock(&log_root_tree->log_mutex); + + ret = update_log_root(trans, log); + BUG_ON(ret); + + mutex_lock(&log_root_tree->log_mutex); + if (atomic_dec_and_test(&log_root_tree->log_writers)) { + smp_mb(); + if (waitqueue_active(&log_root_tree->log_writer_wait)) + wake_up(&log_root_tree->log_writer_wait); + } + + index2 = log_root_tree->log_transid % 2; + if (atomic_read(&log_root_tree->log_commit[index2])) { + wait_log_commit(log_root_tree, log_root_tree->log_transid); + mutex_unlock(&log_root_tree->log_mutex); + goto out; + } + atomic_set(&log_root_tree->log_commit[index2], 1); + + if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) + wait_log_commit(log_root_tree, log_root_tree->log_transid - 1); + + wait_for_writer(log_root_tree); + + ret = btrfs_write_and_wait_marked_extents(log_root_tree, + &log_root_tree->dirty_log_pages); BUG_ON(ret); btrfs_set_super_log_root(&root->fs_info->super_for_commit, - log->fs_info->log_root_tree->node->start); + log_root_tree->node->start); btrfs_set_super_log_root_level(&root->fs_info->super_for_commit, - btrfs_header_level(log->fs_info->log_root_tree->node)); + btrfs_header_level(log_root_tree->node)); + + log_root_tree->log_batch = 0; + log_root_tree->log_transid++; + smp_mb(); + + mutex_unlock(&log_root_tree->log_mutex); + + /* + * nobody else is going to jump in and write the the ctree + * super here because the log_commit atomic below is protecting + * us. We must be called with a transaction handle pinning + * the running transaction open, so a full commit can't hop + * in and cause problems either. + */ + write_ctree_super(trans, root->fs_info->tree_root, 2); - write_ctree_super(trans, log->fs_info->tree_root, 2); - log->fs_info->tree_log_transid++; - log->fs_info->tree_log_batch = 0; - atomic_set(&log->fs_info->tree_log_commit, 0); + atomic_set(&log_root_tree->log_commit[index2], 0); smp_mb(); - if (waitqueue_active(&log->fs_info->tree_log_wait)) - wake_up(&log->fs_info->tree_log_wait); + if (waitqueue_active(&log_root_tree->log_commit_wait[index2])) + wake_up(&log_root_tree->log_commit_wait[index2]); out: - mutex_unlock(&log->fs_info->tree_log_mutex); + atomic_set(&root->log_commit[index1], 0); + smp_mb(); + if (waitqueue_active(&root->log_commit_wait[index1])) + wake_up(&root->log_commit_wait[index1]); return 0; } @@ -2019,37 +2026,17 @@ int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root) start, end, GFP_NOFS); } - log = root->log_root; - ret = btrfs_del_root(trans, root->fs_info->log_root_tree, - &log->root_key); - BUG_ON(ret); + if (log->log_transid > 0) { + ret = btrfs_del_root(trans, root->fs_info->log_root_tree, + &log->root_key); + BUG_ON(ret); + } root->log_root = NULL; - kfree(root->log_root); + free_extent_buffer(log->node); + kfree(log); return 0; } -/* - * helper function to update the item for a given subvolumes log root - * in the tree of log roots - */ -static int update_log_root(struct btrfs_trans_handle *trans, - struct btrfs_root *log) -{ - u64 bytenr = btrfs_root_bytenr(&log->root_item); - int ret; - - if (log->node->start == bytenr) - return 0; - - btrfs_set_root_bytenr(&log->root_item, log->node->start); - btrfs_set_root_generation(&log->root_item, trans->transid); - btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node)); - ret = btrfs_update_root(trans, log->fs_info->log_root_tree, - &log->root_key, &log->root_item); - BUG_ON(ret); - return ret; -} - /* * If both a file and directory are logged, and unlinks or renames are * mixed in, we have a few interesting corners: @@ -2711,11 +2698,6 @@ next_slot: btrfs_free_path(path); btrfs_free_path(dst_path); - - mutex_lock(&root->fs_info->tree_log_mutex); - ret = update_log_root(trans, log); - BUG_ON(ret); - mutex_unlock(&root->fs_info->tree_log_mutex); out: return 0; } -- cgit v1.2.3-70-g09d2 From b51912c91fcf7581cc7b4550f1bb96422809d9ed Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 4 Feb 2009 09:23:24 -0500 Subject: Btrfs: async threads should try harder to find work Tracing shows the delay between when an async thread goes to sleep and when more work is added is often very short. This commit adds a little bit of delay and extra checking to the code right before we schedule out. It allows more work to be added to the worker without requiring notifications from other procs. Signed-off-by: Chris Mason --- fs/btrfs/async-thread.c | 50 +++++++++++++++++++++++++++++++++++++++++++------ fs/btrfs/disk-io.c | 2 ++ 2 files changed, 46 insertions(+), 6 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c index f2e80f3768e..c84ca1f5259 100644 --- a/fs/btrfs/async-thread.c +++ b/fs/btrfs/async-thread.c @@ -19,7 +19,8 @@ #include #include #include -# include +#include +#include #include "async-thread.h" #define WORK_QUEUED_BIT 0 @@ -142,6 +143,7 @@ static int worker_loop(void *arg) struct btrfs_work *work; do { spin_lock_irq(&worker->lock); +again_locked: while (!list_empty(&worker->pending)) { cur = worker->pending.next; work = list_entry(cur, struct btrfs_work, list); @@ -164,14 +166,50 @@ static int worker_loop(void *arg) check_idle_worker(worker); } - worker->working = 0; if (freezing(current)) { + worker->working = 0; + spin_unlock_irq(&worker->lock); refrigerator(); } else { - set_current_state(TASK_INTERRUPTIBLE); spin_unlock_irq(&worker->lock); - if (!kthread_should_stop()) + if (!kthread_should_stop()) { + cpu_relax(); + /* + * we've dropped the lock, did someone else + * jump_in? + */ + smp_mb(); + if (!list_empty(&worker->pending)) + continue; + + /* + * this short schedule allows more work to + * come in without the queue functions + * needing to go through wake_up_process() + * + * worker->working is still 1, so nobody + * is going to try and wake us up + */ + schedule_timeout(1); + smp_mb(); + if (!list_empty(&worker->pending)) + continue; + + /* still no more work?, sleep for real */ + spin_lock_irq(&worker->lock); + set_current_state(TASK_INTERRUPTIBLE); + if (!list_empty(&worker->pending)) + goto again_locked; + + /* + * this makes sure we get a wakeup when someone + * adds something new to the queue + */ + worker->working = 0; + spin_unlock_irq(&worker->lock); + schedule(); + } __set_current_state(TASK_RUNNING); } } while (!kthread_should_stop()); @@ -355,8 +393,8 @@ int btrfs_requeue_work(struct btrfs_work *work) goto out; spin_lock_irqsave(&worker->lock, flags); - atomic_inc(&worker->num_pending); list_add_tail(&work->list, &worker->pending); + atomic_inc(&worker->num_pending); /* by definition we're busy, take ourselves off the idle * list @@ -405,9 +443,9 @@ int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work) spin_lock_irqsave(&worker->lock, flags); + list_add_tail(&work->list, &worker->pending); atomic_inc(&worker->num_pending); check_busy_worker(worker); - list_add_tail(&work->list, &worker->pending); /* * avoid calling into wake_up_process if this thread has already diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 7feac5a475e..9c381004797 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1679,6 +1679,8 @@ struct btrfs_root *open_ctree(struct super_block *sb, * low idle thresh */ fs_info->endio_workers.idle_thresh = 4; + fs_info->endio_meta_workers.idle_thresh = 4; + fs_info->endio_write_workers.idle_thresh = 64; fs_info->endio_meta_write_workers.idle_thresh = 64; -- cgit v1.2.3-70-g09d2 From c487685d7c18a8481900755aa5c56a7a74193101 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 4 Feb 2009 09:24:25 -0500 Subject: Btrfs: hash_lock is no longer needed Before metadata is written to disk, it is updated to reflect that writeout has begun. Once this update is done, the block must be cow'd before it can be modified again. This update was originally synchronized by using a per-fs spinlock. Today the buffers for the metadata blocks are locked before writeout begins, and everyone that tests the flag has the buffer locked as well. So, the per-fs spinlock (called hash_lock for no good reason) is no longer required. Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 7 +------ fs/btrfs/ctree.h | 1 - fs/btrfs/disk-io.c | 4 ---- 3 files changed, 1 insertion(+), 11 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 2603ee539b7..3b6e35aafc9 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -388,16 +388,14 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, WARN_ON(1); } - spin_lock(&root->fs_info->hash_lock); if (btrfs_header_generation(buf) == trans->transid && btrfs_header_owner(buf) == root->root_key.objectid && !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { *cow_ret = buf; - spin_unlock(&root->fs_info->hash_lock); WARN_ON(prealloc_dest); return 0; } - spin_unlock(&root->fs_info->hash_lock); + search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); ret = __btrfs_cow_block(trans, root, buf, parent, parent_slot, cow_ret, search_start, 0, @@ -1376,14 +1374,11 @@ again: int wret; /* is a cow on this block not required */ - spin_lock(&root->fs_info->hash_lock); if (btrfs_header_generation(b) == trans->transid && btrfs_header_owner(b) == root->root_key.objectid && !btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) { - spin_unlock(&root->fs_info->hash_lock); goto cow_done; } - spin_unlock(&root->fs_info->hash_lock); /* ok, we have to cow, is our old prealloc the right * size? diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index de103a8a815..f2b8d26b047 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -703,7 +703,6 @@ struct btrfs_fs_info { struct super_block *sb; struct inode *btree_inode; struct backing_dev_info bdi; - spinlock_t hash_lock; struct mutex trans_mutex; struct mutex tree_log_mutex; struct mutex transaction_kthread_mutex; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 9c381004797..549271607c1 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1503,7 +1503,6 @@ struct btrfs_root *open_ctree(struct super_block *sb, INIT_LIST_HEAD(&fs_info->dead_roots); INIT_LIST_HEAD(&fs_info->hashers); INIT_LIST_HEAD(&fs_info->delalloc_inodes); - spin_lock_init(&fs_info->hash_lock); spin_lock_init(&fs_info->delalloc_lock); spin_lock_init(&fs_info->new_trans_lock); spin_lock_init(&fs_info->ref_cache_lock); @@ -2361,7 +2360,6 @@ int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid) int btree_lock_page_hook(struct page *page) { struct inode *inode = page->mapping->host; - struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct extent_buffer *eb; unsigned long len; @@ -2376,9 +2374,7 @@ int btree_lock_page_hook(struct page *page) goto out; btrfs_tree_lock(eb); - spin_lock(&root->fs_info->hash_lock); btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); - spin_unlock(&root->fs_info->hash_lock); btrfs_tree_unlock(eb); free_extent_buffer(eb); out: -- cgit v1.2.3-70-g09d2 From b4ce94de9b4d64e8ab3cf155d13653c666e22b9b Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 4 Feb 2009 09:25:08 -0500 Subject: Btrfs: Change btree locking to use explicit blocking points Most of the btrfs metadata operations can be protected by a spinlock, but some operations still need to schedule. So far, btrfs has been using a mutex along with a trylock loop, most of the time it is able to avoid going for the full mutex, so the trylock loop is a big performance gain. This commit is step one for getting rid of the blocking locks entirely. btrfs_tree_lock takes a spinlock, and the code explicitly switches to a blocking lock when it starts an operation that can schedule. We'll be able get rid of the blocking locks in smaller pieces over time. Tracing allows us to find the most common cause of blocking, so we can start with the hot spots first. The basic idea is: btrfs_tree_lock() returns with the spin lock held btrfs_set_lock_blocking() sets the EXTENT_BUFFER_BLOCKING bit in the extent buffer flags, and then drops the spin lock. The buffer is still considered locked by all of the btrfs code. If btrfs_tree_lock gets the spinlock but finds the blocking bit set, it drops the spin lock and waits on a wait queue for the blocking bit to go away. Much of the code that needs to set the blocking bit finishes without actually blocking a good percentage of the time. So, an adaptive spin is still used against the blocking bit to avoid very high context switch rates. btrfs_clear_lock_blocking() clears the blocking bit and returns with the spinlock held again. btrfs_tree_unlock() can be called on either blocking or spinning locks, it does the right thing based on the blocking bit. ctree.c has a helper function to set/clear all the locked buffers in a path as blocking. Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 234 +++++++++++++++++++++++++++++++++++++++++++++++-- fs/btrfs/ctree.h | 4 + fs/btrfs/disk-io.c | 10 ++- fs/btrfs/extent-tree.c | 5 ++ fs/btrfs/extent_io.c | 18 ++-- fs/btrfs/extent_io.h | 16 +++- fs/btrfs/inode.c | 3 + fs/btrfs/locking.c | 208 +++++++++++++++++++++++++++++++++++++++---- fs/btrfs/locking.h | 6 ++ fs/btrfs/tree-defrag.c | 1 + fs/btrfs/tree-log.c | 4 + 11 files changed, 470 insertions(+), 39 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 3b6e35aafc9..3af777357ac 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -54,6 +54,31 @@ struct btrfs_path *btrfs_alloc_path(void) return path; } +/* + * set all locked nodes in the path to blocking locks. This should + * be done before scheduling + */ +noinline void btrfs_set_path_blocking(struct btrfs_path *p) +{ + int i; + for (i = 0; i < BTRFS_MAX_LEVEL; i++) { + if (p->nodes[i] && p->locks[i]) + btrfs_set_lock_blocking(p->nodes[i]); + } +} + +/* + * reset all the locked nodes in the patch to spinning locks. + */ +noinline void btrfs_clear_path_blocking(struct btrfs_path *p) +{ + int i; + for (i = 0; i < BTRFS_MAX_LEVEL; i++) { + if (p->nodes[i] && p->locks[i]) + btrfs_clear_lock_blocking(p->nodes[i]); + } +} + /* this also releases the path */ void btrfs_free_path(struct btrfs_path *p) { @@ -272,6 +297,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, if (IS_ERR(cow)) return PTR_ERR(cow); + /* cow is set to blocking by btrfs_init_new_buffer */ + copy_extent_buffer(cow, buf, 0, 0, cow->len); btrfs_set_header_bytenr(cow, cow->start); btrfs_set_header_generation(cow, trans->transid); @@ -397,6 +424,11 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, } search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); + + if (parent) + btrfs_set_lock_blocking(parent); + btrfs_set_lock_blocking(buf); + ret = __btrfs_cow_block(trans, root, buf, parent, parent_slot, cow_ret, search_start, 0, prealloc_dest); @@ -502,6 +534,8 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, if (parent_nritems == 1) return 0; + btrfs_set_lock_blocking(parent); + for (i = start_slot; i < end_slot; i++) { int close = 1; @@ -562,6 +596,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, search_start = last_block; btrfs_tree_lock(cur); + btrfs_set_lock_blocking(cur); err = __btrfs_cow_block(trans, root, cur, parent, i, &cur, search_start, min(16 * blocksize, @@ -860,6 +895,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, return 0; mid = path->nodes[level]; + WARN_ON(!path->locks[level]); WARN_ON(btrfs_header_generation(mid) != trans->transid); @@ -882,6 +918,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, /* promote the child to a root */ child = read_node_slot(root, mid, 0); btrfs_tree_lock(child); + btrfs_set_lock_blocking(child); BUG_ON(!child); ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0); BUG_ON(ret); @@ -898,6 +935,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, add_root_to_dirty_list(root); btrfs_tree_unlock(child); + path->locks[level] = 0; path->nodes[level] = NULL; clean_tree_block(trans, root, mid); @@ -922,6 +960,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, left = read_node_slot(root, parent, pslot - 1); if (left) { btrfs_tree_lock(left); + btrfs_set_lock_blocking(left); wret = btrfs_cow_block(trans, root, left, parent, pslot - 1, &left, 0); if (wret) { @@ -932,6 +971,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, right = read_node_slot(root, parent, pslot + 1); if (right) { btrfs_tree_lock(right); + btrfs_set_lock_blocking(right); wret = btrfs_cow_block(trans, root, right, parent, pslot + 1, &right, 0); if (wret) { @@ -1107,6 +1147,8 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, u32 left_nr; btrfs_tree_lock(left); + btrfs_set_lock_blocking(left); + left_nr = btrfs_header_nritems(left); if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { wret = 1; @@ -1153,7 +1195,10 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, */ if (right) { u32 right_nr; + btrfs_tree_lock(right); + btrfs_set_lock_blocking(right); + right_nr = btrfs_header_nritems(right); if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { wret = 1; @@ -1264,6 +1309,68 @@ static noinline void reada_for_search(struct btrfs_root *root, } } +/* + * returns -EAGAIN if it had to drop the path, or zero if everything was in + * cache + */ +static noinline int reada_for_balance(struct btrfs_root *root, + struct btrfs_path *path, int level) +{ + int slot; + int nritems; + struct extent_buffer *parent; + struct extent_buffer *eb; + u64 gen; + u64 block1 = 0; + u64 block2 = 0; + int ret = 0; + int blocksize; + + parent = path->nodes[level - 1]; + if (!parent) + return 0; + + nritems = btrfs_header_nritems(parent); + slot = path->slots[level]; + blocksize = btrfs_level_size(root, level); + + if (slot > 0) { + block1 = btrfs_node_blockptr(parent, slot - 1); + gen = btrfs_node_ptr_generation(parent, slot - 1); + eb = btrfs_find_tree_block(root, block1, blocksize); + if (eb && btrfs_buffer_uptodate(eb, gen)) + block1 = 0; + free_extent_buffer(eb); + } + if (slot < nritems) { + block2 = btrfs_node_blockptr(parent, slot + 1); + gen = btrfs_node_ptr_generation(parent, slot + 1); + eb = btrfs_find_tree_block(root, block2, blocksize); + if (eb && btrfs_buffer_uptodate(eb, gen)) + block2 = 0; + free_extent_buffer(eb); + } + if (block1 || block2) { + ret = -EAGAIN; + btrfs_release_path(root, path); + if (block1) + readahead_tree_block(root, block1, blocksize, 0); + if (block2) + readahead_tree_block(root, block2, blocksize, 0); + + if (block1) { + eb = read_tree_block(root, block1, blocksize, 0); + free_extent_buffer(eb); + } + if (block1) { + eb = read_tree_block(root, block2, blocksize, 0); + free_extent_buffer(eb); + } + } + return ret; +} + + /* * when we walk down the tree, it is usually safe to unlock the higher layers * in the tree. The exceptions are when our path goes through slot 0, because @@ -1314,6 +1421,32 @@ static noinline void unlock_up(struct btrfs_path *path, int level, } } +/* + * This releases any locks held in the path starting at level and + * going all the way up to the root. + * + * btrfs_search_slot will keep the lock held on higher nodes in a few + * corner cases, such as COW of the block at slot zero in the node. This + * ignores those rules, and it should only be called when there are no + * more updates to be done higher up in the tree. + */ +noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) +{ + int i; + + if (path->keep_locks || path->lowest_level) + return; + + for (i = level; i < BTRFS_MAX_LEVEL; i++) { + if (!path->nodes[i]) + break; + if (!path->locks[i]) + break; + btrfs_tree_unlock(path->nodes[i]); + path->locks[i] = 0; + } +} + /* * look for key in the tree. path is filled in with nodes along the way * if key is found, we return zero and you can find the item in the leaf @@ -1385,6 +1518,7 @@ again: */ if (prealloc_block.objectid && prealloc_block.offset != b->len) { + btrfs_set_path_blocking(p); btrfs_free_reserved_extent(root, prealloc_block.objectid, prealloc_block.offset); @@ -1409,6 +1543,8 @@ again: goto again; } + btrfs_set_path_blocking(p); + wret = btrfs_cow_block(trans, root, b, p->nodes[level + 1], p->slots[level + 1], @@ -1430,6 +1566,22 @@ cow_done: if (!p->skip_locking) p->locks[level] = 1; + btrfs_clear_path_blocking(p); + + /* + * we have a lock on b and as long as we aren't changing + * the tree, there is no way to for the items in b to change. + * It is safe to drop the lock on our parent before we + * go through the expensive btree search on b. + * + * If cow is true, then we might be changing slot zero, + * which may require changing the parent. So, we can't + * drop the lock until after we know which slot we're + * operating on. + */ + if (!cow) + btrfs_unlock_up_safe(p, level + 1); + ret = check_block(root, p, level); if (ret) { ret = -1; @@ -1437,6 +1589,7 @@ cow_done: } ret = bin_search(b, key, level, &slot); + if (level != 0) { if (ret && slot > 0) slot -= 1; @@ -1444,7 +1597,16 @@ cow_done: if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { - int sret = split_node(trans, root, p, level); + int sret; + + sret = reada_for_balance(root, p, level); + if (sret) + goto again; + + btrfs_set_path_blocking(p); + sret = split_node(trans, root, p, level); + btrfs_clear_path_blocking(p); + BUG_ON(sret > 0); if (sret) { ret = sret; @@ -1453,8 +1615,16 @@ cow_done: b = p->nodes[level]; slot = p->slots[level]; } else if (ins_len < 0) { - int sret = balance_level(trans, root, p, - level); + int sret; + + sret = reada_for_balance(root, p, level); + if (sret) + goto again; + + btrfs_set_path_blocking(p); + sret = balance_level(trans, root, p, level); + btrfs_clear_path_blocking(p); + if (sret) { ret = sret; goto done; @@ -1488,7 +1658,7 @@ cow_done: * of the btree by dropping locks before * we read. */ - if (level > 1) { + if (level > 0) { btrfs_release_path(NULL, p); if (tmp) free_extent_buffer(tmp); @@ -1503,6 +1673,7 @@ cow_done: free_extent_buffer(tmp); goto again; } else { + btrfs_set_path_blocking(p); if (tmp) free_extent_buffer(tmp); if (should_reada) @@ -1512,14 +1683,29 @@ cow_done: b = read_node_slot(root, b, slot); } } - if (!p->skip_locking) - btrfs_tree_lock(b); + if (!p->skip_locking) { + int lret; + + btrfs_clear_path_blocking(p); + lret = btrfs_try_spin_lock(b); + + if (!lret) { + btrfs_set_path_blocking(p); + btrfs_tree_lock(b); + btrfs_clear_path_blocking(p); + } + } } else { p->slots[level] = slot; if (ins_len > 0 && btrfs_leaf_free_space(root, b) < ins_len) { - int sret = split_leaf(trans, root, key, + int sret; + + btrfs_set_path_blocking(p); + sret = split_leaf(trans, root, key, p, ins_len, ret == 0); + btrfs_clear_path_blocking(p); + BUG_ON(sret > 0); if (sret) { ret = sret; @@ -1533,12 +1719,16 @@ cow_done: } ret = 1; done: + /* + * we don't really know what they plan on doing with the path + * from here on, so for now just mark it as blocking + */ + btrfs_set_path_blocking(p); if (prealloc_block.objectid) { btrfs_free_reserved_extent(root, prealloc_block.objectid, prealloc_block.offset); } - return ret; } @@ -1562,6 +1752,8 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans, ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb, 0); BUG_ON(ret); + btrfs_set_lock_blocking(eb); + parent = eb; while (1) { level = btrfs_header_level(parent); @@ -1586,6 +1778,7 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans, eb = read_tree_block(root, bytenr, blocksize, generation); btrfs_tree_lock(eb); + btrfs_set_lock_blocking(eb); } /* @@ -1610,6 +1803,7 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans, eb = read_tree_block(root, bytenr, blocksize, generation); btrfs_tree_lock(eb); + btrfs_set_lock_blocking(eb); } ret = btrfs_cow_block(trans, root, eb, parent, slot, @@ -2156,6 +2350,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root right = read_node_slot(root, upper, slot + 1); btrfs_tree_lock(right); + btrfs_set_lock_blocking(right); + free_space = btrfs_leaf_free_space(root, right); if (free_space < data_size) goto out_unlock; @@ -2351,6 +2547,8 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root left = read_node_slot(root, path->nodes[1], slot - 1); btrfs_tree_lock(left); + btrfs_set_lock_blocking(left); + free_space = btrfs_leaf_free_space(root, left); if (free_space < data_size) { ret = 1; @@ -2809,6 +3007,12 @@ int btrfs_split_item(struct btrfs_trans_handle *trans, path->keep_locks = 0; BUG_ON(ret); + /* + * make sure any changes to the path from split_leaf leave it + * in a blocking state + */ + btrfs_set_path_blocking(path); + leaf = path->nodes[0]; BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); @@ -3338,6 +3542,7 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, BUG(); } out: + btrfs_unlock_up_safe(path, 1); return ret; } @@ -3705,12 +3910,14 @@ find_next_key: */ if (slot >= nritems) { path->slots[level] = slot; + btrfs_set_path_blocking(path); sret = btrfs_find_next_key(root, path, min_key, level, cache_only, min_trans); if (sret == 0) { btrfs_release_path(root, path); goto again; } else { + btrfs_clear_path_blocking(path); goto out; } } @@ -3722,16 +3929,20 @@ find_next_key: unlock_up(path, level, 1); goto out; } + btrfs_set_path_blocking(path); cur = read_node_slot(root, cur, slot); btrfs_tree_lock(cur); + path->locks[level - 1] = 1; path->nodes[level - 1] = cur; unlock_up(path, level, 1); + btrfs_clear_path_blocking(path); } out: if (ret == 0) memcpy(min_key, &found_key, sizeof(found_key)); + btrfs_set_path_blocking(path); return ret; } @@ -3827,6 +4038,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) if (ret < 0) return ret; + btrfs_set_path_blocking(path); nritems = btrfs_header_nritems(path->nodes[0]); /* * by releasing the path above we dropped all our locks. A balance @@ -3857,6 +4069,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) free_extent_buffer(next); } + /* the path was set to blocking above */ if (level == 1 && (path->locks[1] || path->skip_locking) && path->reada) reada_for_search(root, path, level, slot, 0); @@ -3865,6 +4078,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) if (!path->skip_locking) { WARN_ON(!btrfs_tree_locked(c)); btrfs_tree_lock(next); + btrfs_set_lock_blocking(next); } break; } @@ -3881,12 +4095,15 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) path->locks[level] = 1; if (!level) break; + + btrfs_set_path_blocking(path); if (level == 1 && path->locks[1] && path->reada) reada_for_search(root, path, level, slot, 0); next = read_node_slot(root, next, 0); if (!path->skip_locking) { WARN_ON(!btrfs_tree_locked(path->nodes[level])); btrfs_tree_lock(next); + btrfs_set_lock_blocking(next); } } done: @@ -3911,6 +4128,7 @@ int btrfs_previous_item(struct btrfs_root *root, while (1) { if (path->slots[0] == 0) { + btrfs_set_path_blocking(path); ret = btrfs_prev_leaf(root, path); if (ret != 0) return ret; diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index f2b8d26b047..531db112c8b 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1835,6 +1835,10 @@ void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p); struct btrfs_path *btrfs_alloc_path(void); void btrfs_free_path(struct btrfs_path *p); void btrfs_init_path(struct btrfs_path *p); +void btrfs_set_path_blocking(struct btrfs_path *p); +void btrfs_clear_path_blocking(struct btrfs_path *p); +void btrfs_unlock_up_safe(struct btrfs_path *p, int level); + int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int slot, int nr); int btrfs_del_leaf(struct btrfs_trans_handle *trans, diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 549271607c1..5aebddd7119 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -799,7 +799,7 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr, ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid); if (ret == 0) - buf->flags |= EXTENT_UPTODATE; + set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags); else WARN_ON(1); return buf; @@ -813,6 +813,10 @@ int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, if (btrfs_header_generation(buf) == root->fs_info->running_transaction->transid) { WARN_ON(!btrfs_tree_locked(buf)); + + /* ugh, clear_extent_buffer_dirty can be expensive */ + btrfs_set_lock_blocking(buf); + clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf); } @@ -2311,6 +2315,8 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf) u64 transid = btrfs_header_generation(buf); struct inode *btree_inode = root->fs_info->btree_inode; + btrfs_set_lock_blocking(buf); + WARN_ON(!btrfs_tree_locked(buf)); if (transid != root->fs_info->generation) { printk(KERN_CRIT "btrfs transid mismatch buffer %llu, " @@ -2353,7 +2359,7 @@ int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid) int ret; ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid); if (ret == 0) - buf->flags |= EXTENT_UPTODATE; + set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags); return ret; } diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 7a22f2e6ec4..ed1e25d7248 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3407,7 +3407,10 @@ struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, btrfs_set_header_generation(buf, trans->transid); btrfs_tree_lock(buf); clean_tree_block(trans, root, buf); + + btrfs_set_lock_blocking(buf); btrfs_set_buffer_uptodate(buf); + if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { set_extent_dirty(&root->dirty_log_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); @@ -3416,6 +3419,7 @@ struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, buf->start + buf->len - 1, GFP_NOFS); } trans->blocks_used++; + /* this returns a buffer locked for blocking */ return buf; } @@ -3752,6 +3756,7 @@ static noinline int walk_down_subtree(struct btrfs_trans_handle *trans, next = read_tree_block(root, bytenr, blocksize, ptr_gen); btrfs_tree_lock(next); + btrfs_set_lock_blocking(next); ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize, &refs); diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 2ea7f052722..dd5df53e045 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2990,7 +2990,9 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree, eb = kmem_cache_zalloc(extent_buffer_cache, mask); eb->start = start; eb->len = len; - mutex_init(&eb->mutex); + spin_lock_init(&eb->lock); + init_waitqueue_head(&eb->lock_wq); + #if LEAK_DEBUG spin_lock_irqsave(&leak_lock, flags); list_add(&eb->leak_list, &buffers); @@ -3071,8 +3073,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, unlock_page(p); } if (uptodate) - eb->flags |= EXTENT_UPTODATE; - eb->flags |= EXTENT_BUFFER_FILLED; + set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); spin_lock(&tree->buffer_lock); exists = buffer_tree_insert(tree, start, &eb->rb_node); @@ -3226,7 +3227,7 @@ int clear_extent_buffer_uptodate(struct extent_io_tree *tree, unsigned long num_pages; num_pages = num_extent_pages(eb->start, eb->len); - eb->flags &= ~EXTENT_UPTODATE; + clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, GFP_NOFS); @@ -3297,7 +3298,7 @@ int extent_buffer_uptodate(struct extent_io_tree *tree, struct page *page; int pg_uptodate = 1; - if (eb->flags & EXTENT_UPTODATE) + if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) return 1; ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1, @@ -3333,7 +3334,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, struct bio *bio = NULL; unsigned long bio_flags = 0; - if (eb->flags & EXTENT_UPTODATE) + if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) return 0; if (test_range_bit(tree, eb->start, eb->start + eb->len - 1, @@ -3364,7 +3365,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, } if (all_uptodate) { if (start_i == 0) - eb->flags |= EXTENT_UPTODATE; + set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); goto unlock_exit; } @@ -3400,7 +3401,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, } if (!ret) - eb->flags |= EXTENT_UPTODATE; + set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); return ret; unlock_exit: @@ -3497,7 +3498,6 @@ int map_extent_buffer(struct extent_buffer *eb, unsigned long start, unmap_extent_buffer(eb, eb->map_token, km); eb->map_token = NULL; save = 1; - WARN_ON(!mutex_is_locked(&eb->mutex)); } err = map_private_extent_buffer(eb, start, min_len, token, map, map_start, map_len, km); diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index e80c6d96b31..1f9df88afbf 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -22,6 +22,10 @@ /* flags for bio submission */ #define EXTENT_BIO_COMPRESSED 1 +/* these are bit numbers for test/set bit */ +#define EXTENT_BUFFER_UPTODATE 0 +#define EXTENT_BUFFER_BLOCKING 1 + /* * page->private values. Every page that is controlled by the extent * map has page->private set to one. @@ -95,11 +99,19 @@ struct extent_buffer { unsigned long map_start; unsigned long map_len; struct page *first_page; + unsigned long bflags; atomic_t refs; - int flags; struct list_head leak_list; struct rb_node rb_node; - struct mutex mutex; + + /* the spinlock is used to protect most operations */ + spinlock_t lock; + + /* + * when we keep the lock held while blocking, waiters go onto + * the wq + */ + wait_queue_head_t lock_wq; }; struct extent_map_tree; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 4a79e1c5ebd..ebd7d6c37df 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -50,6 +50,7 @@ #include "tree-log.h" #include "ref-cache.h" #include "compression.h" +#include "locking.h" struct btrfs_iget_args { u64 ino; @@ -2021,6 +2022,7 @@ void btrfs_read_locked_inode(struct inode *inode) BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); alloc_group_block = btrfs_inode_block_group(leaf, inode_item); + BTRFS_I(inode)->block_group = btrfs_find_block_group(root, 0, alloc_group_block, 0); btrfs_free_path(path); @@ -2117,6 +2119,7 @@ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, goto failed; } + btrfs_unlock_up_safe(path, 1); leaf = path->nodes[0]; inode_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 39bae7761db..68fd9ccf180 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -26,45 +26,215 @@ #include "locking.h" /* - * locks the per buffer mutex in an extent buffer. This uses adaptive locks - * and the spin is not tuned very extensively. The spinning does make a big - * difference in almost every workload, but spinning for the right amount of - * time needs some help. - * - * In general, we want to spin as long as the lock holder is doing btree - * searches, and we should give up if they are in more expensive code. + * btrfs_header_level() isn't free, so don't call it when lockdep isn't + * on */ +#ifdef CONFIG_DEBUG_LOCK_ALLOC +static inline void spin_nested(struct extent_buffer *eb) +{ + spin_lock_nested(&eb->lock, BTRFS_MAX_LEVEL - btrfs_header_level(eb)); +} +#else +static inline void spin_nested(struct extent_buffer *eb) +{ + spin_lock(&eb->lock); +} +#endif -int btrfs_tree_lock(struct extent_buffer *eb) +/* + * Setting a lock to blocking will drop the spinlock and set the + * flag that forces other procs who want the lock to wait. After + * this you can safely schedule with the lock held. + */ +void btrfs_set_lock_blocking(struct extent_buffer *eb) { - int i; + if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) { + set_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags); + spin_unlock(&eb->lock); + } + /* exit with the spin lock released and the bit set */ +} - if (mutex_trylock(&eb->mutex)) - return 0; +/* + * clearing the blocking flag will take the spinlock again. + * After this you can't safely schedule + */ +void btrfs_clear_lock_blocking(struct extent_buffer *eb) +{ + if (test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) { + spin_nested(eb); + clear_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags); + smp_mb__after_clear_bit(); + } + /* exit with the spin lock held */ +} + +/* + * unfortunately, many of the places that currently set a lock to blocking + * don't end up blocking for every long, and often they don't block + * at all. For a dbench 50 run, if we don't spin one the blocking bit + * at all, the context switch rate can jump up to 400,000/sec or more. + * + * So, we're still stuck with this crummy spin on the blocking bit, + * at least until the most common causes of the short blocks + * can be dealt with. + */ +static int btrfs_spin_on_block(struct extent_buffer *eb) +{ + int i; for (i = 0; i < 512; i++) { cpu_relax(); - if (mutex_trylock(&eb->mutex)) + if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) + return 1; + if (need_resched()) + break; + } + return 0; +} + +/* + * This is somewhat different from trylock. It will take the + * spinlock but if it finds the lock is set to blocking, it will + * return without the lock held. + * + * returns 1 if it was able to take the lock and zero otherwise + * + * After this call, scheduling is not safe without first calling + * btrfs_set_lock_blocking() + */ +int btrfs_try_spin_lock(struct extent_buffer *eb) +{ + int i; + + spin_nested(eb); + if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) + return 1; + spin_unlock(&eb->lock); + + /* spin for a bit on the BLOCKING flag */ + for (i = 0; i < 2; i++) { + if (!btrfs_spin_on_block(eb)) + break; + + spin_nested(eb); + if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) + return 1; + spin_unlock(&eb->lock); + } + return 0; +} + +/* + * the autoremove wake function will return 0 if it tried to wake up + * a process that was already awake, which means that process won't + * count as an exclusive wakeup. The waitq code will continue waking + * procs until it finds one that was actually sleeping. + * + * For btrfs, this isn't quite what we want. We want a single proc + * to be notified that the lock is ready for taking. If that proc + * already happen to be awake, great, it will loop around and try for + * the lock. + * + * So, btrfs_wake_function always returns 1, even when the proc that we + * tried to wake up was already awake. + */ +static int btrfs_wake_function(wait_queue_t *wait, unsigned mode, + int sync, void *key) +{ + autoremove_wake_function(wait, mode, sync, key); + return 1; +} + +/* + * returns with the extent buffer spinlocked. + * + * This will spin and/or wait as required to take the lock, and then + * return with the spinlock held. + * + * After this call, scheduling is not safe without first calling + * btrfs_set_lock_blocking() + */ +int btrfs_tree_lock(struct extent_buffer *eb) +{ + DEFINE_WAIT(wait); + wait.func = btrfs_wake_function; + + while(1) { + spin_nested(eb); + + /* nobody is blocking, exit with the spinlock held */ + if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) return 0; + + /* + * we have the spinlock, but the real owner is blocking. + * wait for them + */ + spin_unlock(&eb->lock); + + /* + * spin for a bit, and if the blocking flag goes away, + * loop around + */ + if (btrfs_spin_on_block(eb)) + continue; + + prepare_to_wait_exclusive(&eb->lock_wq, &wait, + TASK_UNINTERRUPTIBLE); + + if (test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) + schedule(); + + finish_wait(&eb->lock_wq, &wait); } - cpu_relax(); - mutex_lock_nested(&eb->mutex, BTRFS_MAX_LEVEL - btrfs_header_level(eb)); return 0; } +/* + * Very quick trylock, this does not spin or schedule. It returns + * 1 with the spinlock held if it was able to take the lock, or it + * returns zero if it was unable to take the lock. + * + * After this call, scheduling is not safe without first calling + * btrfs_set_lock_blocking() + */ int btrfs_try_tree_lock(struct extent_buffer *eb) { - return mutex_trylock(&eb->mutex); + if (spin_trylock(&eb->lock)) { + if (test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) { + /* + * we've got the spinlock, but the real owner is + * blocking. Drop the spinlock and return failure + */ + spin_unlock(&eb->lock); + return 0; + } + return 1; + } + /* someone else has the spinlock giveup */ + return 0; } int btrfs_tree_unlock(struct extent_buffer *eb) { - mutex_unlock(&eb->mutex); + /* + * if we were a blocking owner, we don't have the spinlock held + * just clear the bit and look for waiters + */ + if (test_and_clear_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) + smp_mb__after_clear_bit(); + else + spin_unlock(&eb->lock); + + if (waitqueue_active(&eb->lock_wq)) + wake_up(&eb->lock_wq); return 0; } int btrfs_tree_locked(struct extent_buffer *eb) { - return mutex_is_locked(&eb->mutex); + return test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags) || + spin_is_locked(&eb->lock); } /* @@ -75,12 +245,14 @@ int btrfs_path_lock_waiting(struct btrfs_path *path, int level) { int i; struct extent_buffer *eb; + for (i = level; i <= level + 1 && i < BTRFS_MAX_LEVEL; i++) { eb = path->nodes[i]; if (!eb) break; smp_mb(); - if (!list_empty(&eb->mutex.wait_list)) + if (spin_is_contended(&eb->lock) || + waitqueue_active(&eb->lock_wq)) return 1; } return 0; diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h index bc1faef1251..d92e707f587 100644 --- a/fs/btrfs/locking.h +++ b/fs/btrfs/locking.h @@ -22,6 +22,12 @@ int btrfs_tree_lock(struct extent_buffer *eb); int btrfs_tree_unlock(struct extent_buffer *eb); int btrfs_tree_locked(struct extent_buffer *eb); + int btrfs_try_tree_lock(struct extent_buffer *eb); +int btrfs_try_spin_lock(struct extent_buffer *eb); + int btrfs_path_lock_waiting(struct btrfs_path *path, int level); + +void btrfs_set_lock_blocking(struct extent_buffer *eb); +void btrfs_clear_lock_blocking(struct extent_buffer *eb); #endif diff --git a/fs/btrfs/tree-defrag.c b/fs/btrfs/tree-defrag.c index 3e8358c3616..98d25fa4570 100644 --- a/fs/btrfs/tree-defrag.c +++ b/fs/btrfs/tree-defrag.c @@ -74,6 +74,7 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans, u32 nritems; root_node = btrfs_lock_root_node(root); + btrfs_set_lock_blocking(root_node); nritems = btrfs_header_nritems(root_node); root->defrag_max.objectid = 0; /* from above we know this is not a leaf */ diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 4f26f3ed0c8..20794290256 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -1615,6 +1615,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans, btrfs_tree_lock(next); clean_tree_block(trans, root, next); + btrfs_set_lock_blocking(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); @@ -1661,6 +1662,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans, next = path->nodes[*level]; btrfs_tree_lock(next); clean_tree_block(trans, root, next); + btrfs_set_lock_blocking(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); @@ -1718,6 +1720,7 @@ static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans, btrfs_tree_lock(next); clean_tree_block(trans, root, next); + btrfs_set_lock_blocking(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); @@ -1790,6 +1793,7 @@ static int walk_log_tree(struct btrfs_trans_handle *trans, btrfs_tree_lock(next); clean_tree_block(trans, log, next); + btrfs_set_lock_blocking(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); -- cgit v1.2.3-70-g09d2 From 4008c04a07c73ec3cb1be4c1391d2159a8f75d6d Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Thu, 12 Feb 2009 14:09:45 -0500 Subject: Btrfs: make a lockdep class for the extent buffer locks Btrfs is currently using spin_lock_nested with a nested value based on the tree depth of the block. But, this doesn't quite work because the max tree depth is bigger than what spin_lock_nested can deal with, and because locks are sometimes taken before the level field is filled in. The solution here is to use lockdep_set_class_and_name instead, and to set the class before unlocking the pages when the block is read from the disk and just after init of a freshly allocated tree block. btrfs_clear_path_blocking is also changed to take the locks in the proper order, and it also makes sure all the locks currently held are properly set to blocking before it tries to retake the spinlocks. Otherwise, lockdep gets upset about bad lock orderin. The lockdep magic cam from Peter Zijlstra Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 45 ++++++++++++++++++++++++++++++++++----------- fs/btrfs/ctree.h | 10 +++------- fs/btrfs/disk-io.c | 46 +++++++++++++++++++++++++++++++++++++++++++++- fs/btrfs/disk-io.h | 10 ++++++++++ fs/btrfs/extent-tree.c | 7 +++++-- fs/btrfs/locking.c | 11 ----------- fs/btrfs/volumes.c | 2 ++ 7 files changed, 99 insertions(+), 32 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index c8f4c540cc2..42491d728e9 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -62,14 +62,38 @@ noinline void btrfs_set_path_blocking(struct btrfs_path *p) /* * reset all the locked nodes in the patch to spinning locks. + * + * held is used to keep lockdep happy, when lockdep is enabled + * we set held to a blocking lock before we go around and + * retake all the spinlocks in the path. You can safely use NULL + * for held */ -noinline void btrfs_clear_path_blocking(struct btrfs_path *p) +noinline void btrfs_clear_path_blocking(struct btrfs_path *p, + struct extent_buffer *held) { int i; - for (i = 0; i < BTRFS_MAX_LEVEL; i++) { + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + /* lockdep really cares that we take all of these spinlocks + * in the right order. If any of the locks in the path are not + * currently blocking, it is going to complain. So, make really + * really sure by forcing the path to blocking before we clear + * the path blocking. + */ + if (held) + btrfs_set_lock_blocking(held); + btrfs_set_path_blocking(p); +#endif + + for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { if (p->nodes[i] && p->locks[i]) btrfs_clear_lock_blocking(p->nodes[i]); } + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + if (held) + btrfs_clear_lock_blocking(held); +#endif } /* this also releases the path */ @@ -279,7 +303,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, trans->transid, level, &ins); BUG_ON(ret); cow = btrfs_init_new_buffer(trans, root, prealloc_dest, - buf->len); + buf->len, level); } else { cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start, @@ -1559,7 +1583,7 @@ cow_done: if (!p->skip_locking) p->locks[level] = 1; - btrfs_clear_path_blocking(p); + btrfs_clear_path_blocking(p, NULL); /* * we have a lock on b and as long as we aren't changing @@ -1598,7 +1622,7 @@ cow_done: btrfs_set_path_blocking(p); sret = split_node(trans, root, p, level); - btrfs_clear_path_blocking(p); + btrfs_clear_path_blocking(p, NULL); BUG_ON(sret > 0); if (sret) { @@ -1618,7 +1642,7 @@ cow_done: btrfs_set_path_blocking(p); sret = balance_level(trans, root, p, level); - btrfs_clear_path_blocking(p); + btrfs_clear_path_blocking(p, NULL); if (sret) { ret = sret; @@ -1681,13 +1705,13 @@ cow_done: if (!p->skip_locking) { int lret; - btrfs_clear_path_blocking(p); + btrfs_clear_path_blocking(p, NULL); lret = btrfs_try_spin_lock(b); if (!lret) { btrfs_set_path_blocking(p); btrfs_tree_lock(b); - btrfs_clear_path_blocking(p); + btrfs_clear_path_blocking(p, b); } } } else { @@ -1699,7 +1723,7 @@ cow_done: btrfs_set_path_blocking(p); sret = split_leaf(trans, root, key, p, ins_len, ret == 0); - btrfs_clear_path_blocking(p); + btrfs_clear_path_blocking(p, NULL); BUG_ON(sret > 0); if (sret) { @@ -3919,7 +3943,6 @@ find_next_key: btrfs_release_path(root, path); goto again; } else { - btrfs_clear_path_blocking(path); goto out; } } @@ -3939,7 +3962,7 @@ find_next_key: path->locks[level - 1] = 1; path->nodes[level - 1] = cur; unlock_up(path, level, 1); - btrfs_clear_path_blocking(path); + btrfs_clear_path_blocking(path, NULL); } out: if (ret == 0) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 3f7a8058df2..766b31ae318 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -43,11 +43,7 @@ struct btrfs_ordered_sum; #define BTRFS_ACL_NOT_CACHED ((void *)-1) -#ifdef CONFIG_LOCKDEP -# define BTRFS_MAX_LEVEL 7 -#else -# define BTRFS_MAX_LEVEL 8 -#endif +#define BTRFS_MAX_LEVEL 8 /* holds pointers to all of the tree roots */ #define BTRFS_ROOT_TREE_OBJECTID 1ULL @@ -1715,7 +1711,8 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, u64 empty_size); struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, - u64 bytenr, u32 blocksize); + u64 bytenr, u32 blocksize, + int level); int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 num_bytes, u64 parent, u64 min_bytes, @@ -1835,7 +1832,6 @@ void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p); struct btrfs_path *btrfs_alloc_path(void); void btrfs_free_path(struct btrfs_path *p); void btrfs_set_path_blocking(struct btrfs_path *p); -void btrfs_clear_path_blocking(struct btrfs_path *p); void btrfs_unlock_up_safe(struct btrfs_path *p, int level); int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 5aebddd7119..adda739a021 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -75,6 +75,40 @@ struct async_submit_bio { struct btrfs_work work; }; +/* These are used to set the lockdep class on the extent buffer locks. + * The class is set by the readpage_end_io_hook after the buffer has + * passed csum validation but before the pages are unlocked. + * + * The lockdep class is also set by btrfs_init_new_buffer on freshly + * allocated blocks. + * + * The class is based on the level in the tree block, which allows lockdep + * to know that lower nodes nest inside the locks of higher nodes. + * + * We also add a check to make sure the highest level of the tree is + * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this + * code needs update as well. + */ +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# if BTRFS_MAX_LEVEL != 8 +# error +# endif +static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1]; +static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = { + /* leaf */ + "btrfs-extent-00", + "btrfs-extent-01", + "btrfs-extent-02", + "btrfs-extent-03", + "btrfs-extent-04", + "btrfs-extent-05", + "btrfs-extent-06", + "btrfs-extent-07", + /* highest possible level */ + "btrfs-extent-08", +}; +#endif + /* * extents on the btree inode are pretty simple, there's one extent * that covers the entire device @@ -347,6 +381,15 @@ static int check_tree_block_fsid(struct btrfs_root *root, return ret; } +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level) +{ + lockdep_set_class_and_name(&eb->lock, + &btrfs_eb_class[level], + btrfs_eb_name[level]); +} +#endif + static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, struct extent_state *state) { @@ -392,6 +435,8 @@ static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, } found_level = btrfs_header_level(eb); + btrfs_set_buffer_lockdep_class(eb, found_level); + ret = csum_tree_block(root, eb, 1); if (ret) ret = -EIO; @@ -1777,7 +1822,6 @@ struct btrfs_root *open_ctree(struct super_block *sb, ret = find_and_setup_root(tree_root, fs_info, BTRFS_DEV_TREE_OBJECTID, dev_root); dev_root->track_dirty = 1; - if (ret) goto fail_extent_root; diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index 494a56eb298..95029db227b 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -101,4 +101,14 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, int btrfs_add_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root); int btree_lock_page_hook(struct page *page); + + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level); +#else +static inline void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, + int level) +{ +} +#endif #endif diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index c59e12036e2..cd86bffbdc9 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3416,7 +3416,8 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, - u64 bytenr, u32 blocksize) + u64 bytenr, u32 blocksize, + int level) { struct extent_buffer *buf; @@ -3424,6 +3425,7 @@ struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, if (!buf) return ERR_PTR(-ENOMEM); btrfs_set_header_generation(buf, trans->transid); + btrfs_set_buffer_lockdep_class(buf, level); btrfs_tree_lock(buf); clean_tree_block(trans, root, buf); @@ -3467,7 +3469,8 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, return ERR_PTR(ret); } - buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize); + buf = btrfs_init_new_buffer(trans, root, ins.objectid, + blocksize, level); return buf; } diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 9ebe9385129..85506c4a3af 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -25,21 +25,10 @@ #include "extent_io.h" #include "locking.h" -/* - * btrfs_header_level() isn't free, so don't call it when lockdep isn't - * on - */ -#ifdef CONFIG_DEBUG_LOCK_ALLOC -static inline void spin_nested(struct extent_buffer *eb) -{ - spin_lock_nested(&eb->lock, BTRFS_MAX_LEVEL - btrfs_header_level(eb)); -} -#else static inline void spin_nested(struct extent_buffer *eb) { spin_lock(&eb->lock); } -#endif /* * Setting a lock to blocking will drop the spinlock and set the diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index c793b6f50d8..1316139bf9e 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3102,6 +3102,8 @@ int btrfs_read_sys_array(struct btrfs_root *root) if (!sb) return -ENOMEM; btrfs_set_buffer_uptodate(sb); + btrfs_set_buffer_lockdep_class(sb, 0); + write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE); array_size = btrfs_super_sys_array_size(super_copy); -- cgit v1.2.3-70-g09d2 From b9447ef80bd301b932ac4d85c9622e929de5fd62 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 9 Mar 2009 11:45:38 -0400 Subject: Btrfs: fix spinlock assertions on UP systems btrfs_tree_locked was being used to make sure a given extent_buffer was properly locked in a few places. But, it wasn't correct for UP compiled kernels. This switches it to using assert_spin_locked instead, and renames it to btrfs_assert_tree_locked to better reflect how it was really being used. Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 10 +++++----- fs/btrfs/disk-io.c | 4 ++-- fs/btrfs/extent-tree.c | 4 ++-- fs/btrfs/locking.c | 6 +++--- fs/btrfs/locking.h | 2 +- 5 files changed, 13 insertions(+), 13 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 42491d728e9..37f31b5529a 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -277,7 +277,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, if (*cow_ret == buf) unlock_orig = 1; - WARN_ON(!btrfs_tree_locked(buf)); + btrfs_assert_tree_locked(buf); if (parent) parent_start = parent->start; @@ -2365,7 +2365,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root if (slot >= btrfs_header_nritems(upper) - 1) return 1; - WARN_ON(!btrfs_tree_locked(path->nodes[1])); + btrfs_assert_tree_locked(path->nodes[1]); right = read_node_slot(root, upper, slot + 1); btrfs_tree_lock(right); @@ -2562,7 +2562,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root if (right_nritems == 0) return 1; - WARN_ON(!btrfs_tree_locked(path->nodes[1])); + btrfs_assert_tree_locked(path->nodes[1]); left = read_node_slot(root, path->nodes[1], slot - 1); btrfs_tree_lock(left); @@ -4101,7 +4101,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) next = read_node_slot(root, c, slot); if (!path->skip_locking) { - WARN_ON(!btrfs_tree_locked(c)); + btrfs_assert_tree_locked(c); btrfs_tree_lock(next); btrfs_set_lock_blocking(next); } @@ -4126,7 +4126,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) reada_for_search(root, path, level, slot, 0); next = read_node_slot(root, next, 0); if (!path->skip_locking) { - WARN_ON(!btrfs_tree_locked(path->nodes[level])); + btrfs_assert_tree_locked(path->nodes[level]); btrfs_tree_lock(next); btrfs_set_lock_blocking(next); } diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index adda739a021..3e18175248e 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -857,7 +857,7 @@ int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *btree_inode = root->fs_info->btree_inode; if (btrfs_header_generation(buf) == root->fs_info->running_transaction->transid) { - WARN_ON(!btrfs_tree_locked(buf)); + btrfs_assert_tree_locked(buf); /* ugh, clear_extent_buffer_dirty can be expensive */ btrfs_set_lock_blocking(buf); @@ -2361,7 +2361,7 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf) btrfs_set_lock_blocking(buf); - WARN_ON(!btrfs_tree_locked(buf)); + btrfs_assert_tree_locked(buf); if (transid != root->fs_info->generation) { printk(KERN_CRIT "btrfs transid mismatch buffer %llu, " "found %llu running %llu\n", diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 6b5966aacf4..9abf81f71c4 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4418,13 +4418,13 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans, path = btrfs_alloc_path(); BUG_ON(!path); - BUG_ON(!btrfs_tree_locked(parent)); + btrfs_assert_tree_locked(parent); parent_level = btrfs_header_level(parent); extent_buffer_get(parent); path->nodes[parent_level] = parent; path->slots[parent_level] = btrfs_header_nritems(parent); - BUG_ON(!btrfs_tree_locked(node)); + btrfs_assert_tree_locked(node); level = btrfs_header_level(node); extent_buffer_get(node); path->nodes[level] = node; diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 85506c4a3af..47b0a88c12a 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -220,8 +220,8 @@ int btrfs_tree_unlock(struct extent_buffer *eb) return 0; } -int btrfs_tree_locked(struct extent_buffer *eb) +void btrfs_assert_tree_locked(struct extent_buffer *eb) { - return test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags) || - spin_is_locked(&eb->lock); + if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) + assert_spin_locked(&eb->lock); } diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h index 6bb0afbff92..6c4ce457168 100644 --- a/fs/btrfs/locking.h +++ b/fs/btrfs/locking.h @@ -21,11 +21,11 @@ int btrfs_tree_lock(struct extent_buffer *eb); int btrfs_tree_unlock(struct extent_buffer *eb); -int btrfs_tree_locked(struct extent_buffer *eb); int btrfs_try_tree_lock(struct extent_buffer *eb); int btrfs_try_spin_lock(struct extent_buffer *eb); void btrfs_set_lock_blocking(struct extent_buffer *eb); void btrfs_clear_lock_blocking(struct extent_buffer *eb); +void btrfs_assert_tree_locked(struct extent_buffer *eb); #endif -- cgit v1.2.3-70-g09d2