btrfs: try harder to allocate raid56 stripe cache
The stripe hash table is large, starting with allocation order 4 and can go as
high as order 7 in case lock debugging is turned on and structure padding
happens.
Observed mount failure:
mount: page allocation failure: order:7, mode:0x200050
Pid: 8234, comm: mount Tainted: G W 3.8.0-default+ #267
Call Trace:
[<ffffffff81114353>] warn_alloc_failed+0xf3/0x140
[<ffffffff811171d2>] ? __alloc_pages_direct_compact+0x92/0x250
[<ffffffff81117ac3>] __alloc_pages_nodemask+0x733/0x9d0
[<ffffffff81152878>] ? cache_alloc_refill+0x3f8/0x840
[<ffffffff811528bc>] cache_alloc_refill+0x43c/0x840
[<ffffffff811302eb>] ? is_kernel_percpu_address+0x4b/0x90
[<ffffffffa00a00ac>] ? btrfs_alloc_stripe_hash_table+0x5c/0x130 [btrfs]
[<ffffffff811531d7>] kmem_cache_alloc_trace+0x247/0x270
[<ffffffffa00a00ac>] btrfs_alloc_stripe_hash_table+0x5c/0x130 [btrfs]
[<ffffffffa003133f>] open_ctree+0xb2f/0x1f90 [btrfs]
[<ffffffff81397289>] ? string+0x49/0xe0
[<ffffffff813987b3>] ? vsnprintf+0x443/0x5d0
[<ffffffffa0007cb6>] btrfs_mount+0x526/0x600 [btrfs]
[<ffffffff8115127c>] ? cache_alloc_debugcheck_after+0x4c/0x200
[<ffffffff81162b90>] mount_fs+0x20/0xe0
[<ffffffff8117db26>] vfs_kern_mount+0x76/0x120
[<ffffffff811801b6>] do_mount+0x386/0x980
[<ffffffff8112a5cb>] ? strndup_user+0x5b/0x80
[<ffffffff81180840>] sys_mount+0x90/0xe0
[<ffffffff81962e99>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 5031e6d..02369a3 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2197,7 +2197,7 @@
ret = btrfs_alloc_stripe_hash_table(fs_info);
if (ret) {
- err = -ENOMEM;
+ err = ret;
goto fail_alloc;
}
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index e34e568..0722205 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -188,13 +188,25 @@
struct btrfs_stripe_hash *h;
int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS;
int i;
+ int table_size;
if (info->stripe_hash_table)
return 0;
- table = kzalloc(sizeof(*table) + sizeof(*h) * num_entries, GFP_NOFS);
- if (!table)
- return -ENOMEM;
+ /*
+ * The table is large, starting with order 4 and can go as high as
+ * order 7 in case lock debugging is turned on.
+ *
+ * Try harder to allocate and fallback to vmalloc to lower the chance
+ * of a failing mount.
+ */
+ table_size = sizeof(*table) + sizeof(*h) * num_entries;
+ table = kzalloc(table_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
+ if (!table) {
+ table = vzalloc(table_size);
+ if (!table)
+ return -ENOMEM;
+ }
spin_lock_init(&table->cache_lock);
INIT_LIST_HEAD(&table->stripe_cache);
@@ -209,8 +221,12 @@
}
x = cmpxchg(&info->stripe_hash_table, NULL, table);
- if (x)
- kfree(x);
+ if (x) {
+ if (is_vmalloc_addr(x))
+ vfree(x);
+ else
+ kfree(x);
+ }
return 0;
}
@@ -420,7 +436,10 @@
if (!info->stripe_hash_table)
return;
btrfs_clear_rbio_cache(info);
- kfree(info->stripe_hash_table);
+ if (is_vmalloc_addr(info->stripe_hash_table))
+ vfree(info->stripe_hash_table);
+ else
+ kfree(info->stripe_hash_table);
info->stripe_hash_table = NULL;
}