From 5b21f2ed3f2947b5195b65c9fdbdd9e52904cc03 Mon Sep 17 00:00:00 2001 From: Zheng Yan Date: Fri, 26 Sep 2008 10:05:38 -0400 Subject: Btrfs: extent_map and data=ordered fixes for space balancing * Add an EXTENT_BOUNDARY state bit to keep the writepage code from merging data extents that are in the process of being relocated. This allows us to do accounting for them properly. * The balancing code relocates data extents indepdent of the underlying inode. The extent_map code was modified to properly account for things moving around (invalidating extent_map caches in the inode). * Don't take the drop_mutex in the create_subvol ioctl. It isn't required. * Fix walking of the ordered extent list to avoid races with sys_unlink * Change the lock ordering rules. Transaction start goes outside the drop_mutex. This allows btrfs_commit_transaction to directly drop the relocation trees. Signed-off-by: Chris Mason --- fs/btrfs/ordered-data.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'fs/btrfs/ordered-data.c') diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c index da6d43eb41db..951eacff2420 100644 --- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -309,7 +309,6 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only) { struct list_head splice; struct list_head *cur; - struct list_head *tmp; struct btrfs_ordered_extent *ordered; struct inode *inode; @@ -317,37 +316,38 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only) spin_lock(&root->fs_info->ordered_extent_lock); list_splice_init(&root->fs_info->ordered_extents, &splice); - list_for_each_safe(cur, tmp, &splice) { + while (!list_empty(&splice)) { cur = splice.next; ordered = list_entry(cur, struct btrfs_ordered_extent, root_extent_list); if (nocow_only && !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) { + list_move(&ordered->root_extent_list, + &root->fs_info->ordered_extents); cond_resched_lock(&root->fs_info->ordered_extent_lock); continue; } list_del_init(&ordered->root_extent_list); atomic_inc(&ordered->refs); - inode = ordered->inode; /* - * the inode can't go away until all the pages are gone - * and the pages won't go away while there is still - * an ordered extent and the ordered extent won't go - * away until it is off this list. So, we can safely - * increment i_count here and call iput later + * the inode may be getting freed (in sys_unlink path). */ - atomic_inc(&inode->i_count); + inode = igrab(ordered->inode); + spin_unlock(&root->fs_info->ordered_extent_lock); - btrfs_start_ordered_extent(inode, ordered, 1); - btrfs_put_ordered_extent(ordered); - iput(inode); + if (inode) { + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + iput(inode); + } else { + btrfs_put_ordered_extent(ordered); + } spin_lock(&root->fs_info->ordered_extent_lock); } - list_splice_init(&splice, &root->fs_info->ordered_extents); spin_unlock(&root->fs_info->ordered_extent_lock); return 0; } -- cgit v1.2.1