From d864546231e051e33e200025e4a6988b996f2654 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Wed, 30 Mar 2022 12:14:07 +0300 Subject: [PATCH] btrfs: simplify code flow in btrfs_ioctl_balance Move code in btrfs_ioctl_balance to simplify its flow. This is possible thanks to the removal of balance v1 ioctl and ensuring 'arg' argument is always present. First move the code duplicating the userspace arg to the kernel 'barg'. This makes the out_unlock label redundant. Secondly, check the validity of bargs::flags before copying to the dynamically allocated 'bctl'. This removes the need for the out_bctl label. Reviewed-by: Sweet Tea Dorminy Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/ioctl.c | 35 ++++++++++++++++------------------- 1 file changed, 16 insertions(+), 19 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 95e47e6..d1e1edd 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4353,6 +4353,13 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) if (ret) return ret; + bargs = memdup_user(arg, sizeof(*bargs)); + if (IS_ERR(bargs)) { + ret = PTR_ERR(bargs); + bargs = NULL; + goto out; + } + again: if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) { mutex_lock(&fs_info->balance_mutex); @@ -4400,17 +4407,10 @@ again: } locked: - - bargs = memdup_user(arg, sizeof(*bargs)); - if (IS_ERR(bargs)) { - ret = PTR_ERR(bargs); - goto out_unlock; - } - if (bargs->flags & BTRFS_BALANCE_RESUME) { if (!fs_info->balance_ctl) { ret = -ENOTCONN; - goto out_bargs; + goto out_unlock; } bctl = fs_info->balance_ctl; @@ -4422,15 +4422,20 @@ locked: goto do_balance; } + if (bargs->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) { + ret = -EINVAL; + goto out_unlock; + } + if (fs_info->balance_ctl) { ret = -EINPROGRESS; - goto out_bargs; + goto out_unlock; } bctl = kzalloc(sizeof(*bctl), GFP_KERNEL); if (!bctl) { ret = -ENOMEM; - goto out_bargs; + goto out_unlock; } memcpy(&bctl->data, &bargs->data, sizeof(bctl->data)); @@ -4438,12 +4443,6 @@ locked: memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys)); bctl->flags = bargs->flags; - - if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) { - ret = -EINVAL; - goto out_bctl; - } - do_balance: /* * Ownership of bctl and exclusive operation goes to btrfs_balance. @@ -4461,16 +4460,14 @@ do_balance: ret = -EFAULT; } -out_bctl: kfree(bctl); -out_bargs: - kfree(bargs); out_unlock: mutex_unlock(&fs_info->balance_mutex); if (need_unlock) btrfs_exclop_finish(fs_info); out: mnt_drop_write_file(file); + kfree(bargs); return ret; } -- 2.7.4