diff options
| author | Filipe Manana <fdmanana@suse.com> | 2018-12-13 21:16:45 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-23 20:11:22 +0100 |
| commit | 80dcd07c27dfe24f79a40897d8ecac4c38b1875d (patch) | |
| tree | b4fa815e032d6295ab6a478b5e00bb23cabd1dc1 | |
| parent | 98bb142aaff299c44486d4e763c6da58fb913daf (diff) | |
| download | talos-obmc-linux-80dcd07c27dfe24f79a40897d8ecac4c38b1875d.tar.gz talos-obmc-linux-80dcd07c27dfe24f79a40897d8ecac4c38b1875d.zip | |
Btrfs: setup a nofs context for memory allocation at btrfs_create_tree()
commit b89f6d1fcb30a8cbdc18ce00c7d93792076af453 upstream.
We are holding a transaction handle when creating a tree, therefore we can
not allocate the root using GFP_KERNEL, as we could deadlock if reclaim is
triggered by the allocation, therefore setup a nofs context.
Fixes: 74e4d82757f74 ("btrfs: let callers of btrfs_alloc_root pass gfp flags")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/btrfs/disk-io.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 6a2a2a951705..888d72dda794 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -17,6 +17,7 @@ #include <linux/semaphore.h> #include <linux/error-injection.h> #include <linux/crc32c.h> +#include <linux/sched/mm.h> #include <asm/unaligned.h> #include "ctree.h" #include "disk-io.h" @@ -1258,10 +1259,17 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans, struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_root *root; struct btrfs_key key; + unsigned int nofs_flag; int ret = 0; uuid_le uuid = NULL_UUID_LE; + /* + * We're holding a transaction handle, so use a NOFS memory allocation + * context to avoid deadlock if reclaim happens. + */ + nofs_flag = memalloc_nofs_save(); root = btrfs_alloc_root(fs_info, GFP_KERNEL); + memalloc_nofs_restore(nofs_flag); if (!root) return ERR_PTR(-ENOMEM); |
