From mboxrd@z Thu Jan 1 00:00:00 1970 From: Giuseppe Scrivano Subject: [PATCH] Btrfs: don't allocate more than max_available bytes when looped Date: Mon, 03 Aug 2009 00:24:47 +0200 Message-ID: <87fxc9yhu8.fsf@master.homenet> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: linux-btrfs@vger.kernel.org Return-path: List-ID: Hello, I had a problem running this simple test case that I was writing to test the GNU coreutils cp tool: truncate --size=256M btrfs.img mkfs.btrfs btrfs.img mkdir btrfs mount -t btrfs -o loop btrfs.img btrfs dd bs=1M count=200 if=/dev/zero of=btrfs/alloc.test with the current git version I get an ENOSPC error on dd, even if the available space is 256M. The simple patch that I have attached seems to fix it. Am I missing someting? If there is something wrong please let me know and I'll try to fix it. Regards, Giuseppe >>From d6345f720f9fa5e60edd904d90d56bf9e96fb118 Mon Sep 17 00:00:00 2001 From: Giuseppe Scrivano Date: Sun, 2 Aug 2009 23:29:21 +0200 Subject: [PATCH] Btrfs: don't allocate more than max_available bytes when looped avoid that __btrfs_alloc_chunk can try to allocate more than max_available bytes if it wasn't possible on the first attempt. --- fs/btrfs/volumes.c | 13 ++++++++----- 1 files changed, 8 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 5dbefd1..38d93f6 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2180,8 +2180,8 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1), max_chunk_size); -again: max_avail = 0; +again: if (!map || map->num_stripes != num_stripes) { kfree(map); map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS); @@ -2196,11 +2196,12 @@ again: do_div(calc_size, stripe_len); calc_size *= stripe_len; } - /* we don't want tiny stripes */ - calc_size = max_t(u64, min_stripe_size, calc_size); - do_div(calc_size, stripe_len); - calc_size *= stripe_len; + /* we don't want tiny stripes */ + calc_size = max_t(u64, min_stripe_size, calc_size); + + do_div(calc_size, stripe_len); + calc_size *= stripe_len; cur = fs_devices->alloc_list.next; index = 0; @@ -2217,6 +2218,8 @@ again: */ if (!looped) min_free += 1024 * 1024; + else + min_free = min_t(u64, max_avail, min_free); INIT_LIST_HEAD(&private_devs); while (index < num_stripes) { -- 1.6.3.3