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| author | David Sterba <dsterba@suse.cz> | 2016-05-04 11:32:00 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2016-05-06 15:22:49 +0200 |
| commit | 7ab19625a911f7568ec85302e3aa7a64186006c8 (patch) | |
| tree | 2745e636072f4e01263034a77bb434ee93afbb4d /fs | |
| parent | 48b3b9d401ec86899a52003b37331190a35a81a6 (diff) | |
| download | linux-7ab19625a911f7568ec85302e3aa7a64186006c8.tar.gz linux-7ab19625a911f7568ec85302e3aa7a64186006c8.tar.bz2 linux-7ab19625a911f7568ec85302e3aa7a64186006c8.zip | |
btrfs: add write protection to SET_FEATURES ioctl
Perform the want_write check if we get far enough to do any writes.
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/ioctl.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 798f58e7338e..1e8ce5247a81 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -5406,9 +5406,15 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg) if (ret) return ret; + ret = mnt_want_write_file(file); + if (ret) + return ret; + trans = btrfs_start_transaction(root, 0); - if (IS_ERR(trans)) - return PTR_ERR(trans); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_drop_write; + } spin_lock(&root->fs_info->super_lock); newflags = btrfs_super_compat_flags(super_block); @@ -5427,7 +5433,11 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg) btrfs_set_super_incompat_flags(super_block, newflags); spin_unlock(&root->fs_info->super_lock); - return btrfs_commit_transaction(trans, root); + ret = btrfs_commit_transaction(trans, root); +out_drop_write: + mnt_drop_write_file(file); + + return ret; } long btrfs_ioctl(struct file *file, unsigned int |