Btrfs: use rcu to protect device->name

[platform/adaptation/renesas_rcar/renesas_kernel.git] / fs / btrfs / ioctl.c

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 24b776c..c5254dd 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -52,6 +52,7 @@
 #include "locking.h"
 #include "inode-map.h"
 #include "backref.h"
+#include "rcu-string.h"
 
 /* Mask out flags that are inappropriate for the given type of inode. */
 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
@@ -1345,8 +1346,9 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
        do_div(new_size, root->sectorsize);
        new_size *= root->sectorsize;
 
-       printk(KERN_INFO "btrfs: new size for %s is %llu\n",
-               device->name, (unsigned long long)new_size);
+       printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
+                     rcu_str_deref(device->name),
+                     (unsigned long long)new_size);
 
        if (new_size > old_size) {
                trans = btrfs_start_transaction(root, 0);
@@ -2264,7 +2266,12 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
        di_args->total_bytes = dev->total_bytes;
        memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
        if (dev->name) {
-               strncpy(di_args->path, dev->name, sizeof(di_args->path));
+               struct rcu_string *name;
+
+               rcu_read_lock();
+               name = rcu_dereference(dev->name);
+               strncpy(di_args->path, name->str, sizeof(di_args->path));
+               rcu_read_unlock();
                di_args->path[sizeof(di_args->path) - 1] = 0;
        } else {
                di_args->path[0] = '\0';