From d52a5b5f1fa40804f681cf9868d4a8f90661bdf3 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Wed, 5 Jan 2011 10:07:18 +0000 Subject: [PATCH] btrfs: try to reclaim some space when chunk allocation fails We cannot write data into files when when there is tiny space in the filesystem. Reproduce steps: # mkfs.btrfs /dev/sda1 # mount /dev/sda1 /mnt # dd if=/dev/zero of=/mnt/tmpfile0 bs=4K count=1 # dd if=/dev/zero of=/mnt/tmpfile1 bs=4K count=99999999999999 (fill the filesystem) # umount /mnt # mount /dev/sda1 /mnt # rm -f /mnt/tmpfile0 # dd if=/dev/zero of=/mnt/tmpfile0 bs=4K count=1 (failed with nospec) But if we do the last step again, we can write data successfully. The reason of the problem is that btrfs didn't try to commit the current transaction and reclaim some space when chunk allocation failed. This patch fixes it by committing the current transaction to reclaim some space when chunk allocation fails. Signed-off-by: Miao Xie Reviewed-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index b180efd..3c71d95 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3162,8 +3162,12 @@ alloc: bytes + 2 * 1024 * 1024, alloc_target, 0); btrfs_end_transaction(trans, root); - if (ret < 0) - return ret; + if (ret < 0) { + if (ret != -ENOSPC) + return ret; + else + goto commit_trans; + } if (!data_sinfo) { btrfs_set_inode_space_info(root, inode); @@ -3174,6 +3178,7 @@ alloc: spin_unlock(&data_sinfo->lock); /* commit the current transaction and try again */ +commit_trans: if (!committed && !root->fs_info->open_ioctl_trans) { committed = 1; trans = btrfs_join_transaction(root, 1); -- 2.7.4