From 39fb26c398ddf8d7794a85e896cfe1a42e55524b Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Wed, 14 Dec 2011 20:12:02 -0500 Subject: Btrfs: fix inaccurate available space on raid0 profile When we use raid0 as the data profile, df command may show us a very inaccurate value of the available space, which may be much less than the real one. It may make the users puzzled. Fix it by changing the calculation of the available space, and making it be more similar to a fake chunk allocation. Signed-off-by: Miao Xie Signed-off-by: Chris Mason --- fs/btrfs/super.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 1a3ce9e0b495..41495dce4db0 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1079,7 +1079,7 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) u64 avail_space; u64 used_space; u64 min_stripe_size; - int min_stripes = 1; + int min_stripes = 1, num_stripes = 1; int i = 0, nr_devices; int ret; @@ -1093,12 +1093,16 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) /* calc min stripe number for data space alloction */ type = btrfs_get_alloc_profile(root, 1); - if (type & BTRFS_BLOCK_GROUP_RAID0) + if (type & BTRFS_BLOCK_GROUP_RAID0) { min_stripes = 2; - else if (type & BTRFS_BLOCK_GROUP_RAID1) + num_stripes = nr_devices; + } else if (type & BTRFS_BLOCK_GROUP_RAID1) { min_stripes = 2; - else if (type & BTRFS_BLOCK_GROUP_RAID10) + num_stripes = 2; + } else if (type & BTRFS_BLOCK_GROUP_RAID10) { min_stripes = 4; + num_stripes = 4; + } if (type & BTRFS_BLOCK_GROUP_DUP) min_stripe_size = 2 * BTRFS_STRIPE_LEN; @@ -1167,13 +1171,16 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) i = nr_devices - 1; avail_space = 0; while (nr_devices >= min_stripes) { + if (num_stripes > nr_devices) + num_stripes = nr_devices; + if (devices_info[i].max_avail >= min_stripe_size) { int j; u64 alloc_size; - avail_space += devices_info[i].max_avail * min_stripes; + avail_space += devices_info[i].max_avail * num_stripes; alloc_size = devices_info[i].max_avail; - for (j = i + 1 - min_stripes; j <= i; j++) + for (j = i + 1 - num_stripes; j <= i; j++) devices_info[j].max_avail -= alloc_size; } i--; -- cgit v1.2.3-58-ga151