From abccd00f8af27c585be48904515bad5658130e48 Mon Sep 17 00:00:00 2001 From: Hugo Mills Date: Thu, 30 Jan 2014 20:17:00 +0000 Subject: [PATCH] btrfs: Fix 32/64-bit problem with BTRFS_SET_RECEIVED_SUBVOL ioctl The structure for BTRFS_SET_RECEIVED_IOCTL packs differently on 32-bit and 64-bit systems. This means that it is impossible to use btrfs receive on a system with a 64-bit kernel and 32-bit userspace, because the structure size (and hence the ioctl number) is different. This patch adds a compatibility structure and ioctl to deal with the above case. Signed-off-by: Hugo Mills Signed-off-by: Josef Bacik --- fs/btrfs/ioctl.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 111 insertions(+), 12 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index a692aad..d4c1795 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -59,6 +59,32 @@ #include "props.h" #include "sysfs.h" +#ifdef CONFIG_64BIT +/* If we have a 32-bit userspace and 64-bit kernel, then the UAPI + * structures are incorrect, as the timespec structure from userspace + * is 4 bytes too small. We define these alternatives here to teach + * the kernel about the 32-bit struct packing. + */ +struct btrfs_ioctl_timespec_32 { + __u64 sec; + __u32 nsec; +} __attribute__ ((__packed__)); + +struct btrfs_ioctl_received_subvol_args_32 { + char uuid[BTRFS_UUID_SIZE]; /* in */ + __u64 stransid; /* in */ + __u64 rtransid; /* out */ + struct btrfs_ioctl_timespec_32 stime; /* in */ + struct btrfs_ioctl_timespec_32 rtime; /* out */ + __u64 flags; /* in */ + __u64 reserved[16]; /* in */ +} __attribute__ ((__packed__)); + +#define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \ + struct btrfs_ioctl_received_subvol_args_32) +#endif + + static int btrfs_clone(struct inode *src, struct inode *inode, u64 off, u64 olen, u64 olen_aligned, u64 destoff); @@ -4375,10 +4401,9 @@ static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg) return btrfs_qgroup_wait_for_completion(root->fs_info); } -static long btrfs_ioctl_set_received_subvol(struct file *file, - void __user *arg) +static long _btrfs_ioctl_set_received_subvol(struct file *file, + struct btrfs_ioctl_received_subvol_args *sa) { - struct btrfs_ioctl_received_subvol_args *sa = NULL; struct inode *inode = file_inode(file); struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_root_item *root_item = &root->root_item; @@ -4406,13 +4431,6 @@ static long btrfs_ioctl_set_received_subvol(struct file *file, goto out; } - sa = memdup_user(arg, sizeof(*sa)); - if (IS_ERR(sa)) { - ret = PTR_ERR(sa); - sa = NULL; - goto out; - } - /* * 1 - root item * 2 - uuid items (received uuid + subvol uuid) @@ -4466,14 +4484,91 @@ static long btrfs_ioctl_set_received_subvol(struct file *file, goto out; } +out: + up_write(&root->fs_info->subvol_sem); + mnt_drop_write_file(file); + return ret; +} + +#ifdef CONFIG_64BIT +static long btrfs_ioctl_set_received_subvol_32(struct file *file, + void __user *arg) +{ + struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL; + struct btrfs_ioctl_received_subvol_args *args64 = NULL; + int ret = 0; + + args32 = memdup_user(arg, sizeof(*args32)); + if (IS_ERR(args32)) { + ret = PTR_ERR(args32); + args32 = NULL; + goto out; + } + + args64 = kmalloc(sizeof(*args64), GFP_NOFS); + if (IS_ERR(args64)) { + ret = PTR_ERR(args64); + args64 = NULL; + goto out; + } + + memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE); + args64->stransid = args32->stransid; + args64->rtransid = args32->rtransid; + args64->stime.sec = args32->stime.sec; + args64->stime.nsec = args32->stime.nsec; + args64->rtime.sec = args32->rtime.sec; + args64->rtime.nsec = args32->rtime.nsec; + args64->flags = args32->flags; + + ret = _btrfs_ioctl_set_received_subvol(file, args64); + if (ret) + goto out; + + memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE); + args32->stransid = args64->stransid; + args32->rtransid = args64->rtransid; + args32->stime.sec = args64->stime.sec; + args32->stime.nsec = args64->stime.nsec; + args32->rtime.sec = args64->rtime.sec; + args32->rtime.nsec = args64->rtime.nsec; + args32->flags = args64->flags; + + ret = copy_to_user(arg, args32, sizeof(*args32)); + if (ret) + ret = -EFAULT; + +out: + kfree(args32); + kfree(args64); + return ret; +} +#endif + +static long btrfs_ioctl_set_received_subvol(struct file *file, + void __user *arg) +{ + struct btrfs_ioctl_received_subvol_args *sa = NULL; + int ret = 0; + + sa = memdup_user(arg, sizeof(*sa)); + if (IS_ERR(sa)) { + ret = PTR_ERR(sa); + sa = NULL; + goto out; + } + + ret = _btrfs_ioctl_set_received_subvol(file, sa); + + if (ret) + goto out; + ret = copy_to_user(arg, sa, sizeof(*sa)); if (ret) ret = -EFAULT; out: kfree(sa); - up_write(&root->fs_info->subvol_sem); - mnt_drop_write_file(file); return ret; } @@ -4792,6 +4887,10 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_balance_progress(root, argp); case BTRFS_IOC_SET_RECEIVED_SUBVOL: return btrfs_ioctl_set_received_subvol(file, argp); +#ifdef CONFIG_64BIT + case BTRFS_IOC_SET_RECEIVED_SUBVOL_32: + return btrfs_ioctl_set_received_subvol_32(file, argp); +#endif case BTRFS_IOC_SEND: return btrfs_ioctl_send(file, argp); case BTRFS_IOC_GET_DEV_STATS: -- 2.7.4