vfs: create a generic checking function for FS_IOC_FSSETXATTR

Create a generic checking function for the incoming FS_IOC_FSSETXATTR
fsxattr values so that we can standardize some of the implementation
behaviors.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Darrick J. Wong 2019-07-01 08:25:35 -07:00
parent 5aca284210
commit 7b0e492e6b
5 changed files with 98 additions and 51 deletions

View File

@ -375,9 +375,7 @@ static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
struct btrfs_inode *binode = BTRFS_I(file_inode(file));
struct fsxattr fa;
memset(&fa, 0, sizeof(fa));
fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
simple_fill_fsxattr(&fa, btrfs_inode_flags_to_xflags(binode->flags));
if (copy_to_user(arg, &fa, sizeof(fa)))
return -EFAULT;
@ -390,7 +388,7 @@ static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
struct btrfs_inode *binode = BTRFS_I(inode);
struct btrfs_root *root = binode->root;
struct btrfs_trans_handle *trans;
struct fsxattr fa;
struct fsxattr fa, old_fa;
unsigned old_flags;
unsigned old_i_flags;
int ret = 0;
@ -401,7 +399,6 @@ static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
if (btrfs_root_readonly(root))
return -EROFS;
memset(&fa, 0, sizeof(fa));
if (copy_from_user(&fa, arg, sizeof(fa)))
return -EFAULT;
@ -421,13 +418,11 @@ static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
old_flags = binode->flags;
old_i_flags = inode->i_flags;
/* We need the capabilities to change append-only or immutable inode */
if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
(fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
!capable(CAP_LINUX_IMMUTABLE)) {
ret = -EPERM;
simple_fill_fsxattr(&old_fa,
btrfs_inode_flags_to_xflags(binode->flags));
ret = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
if (ret)
goto out_unlock;
}
if (fa.fsx_xflags & FS_XFLAG_SYNC)
binode->flags |= BTRFS_INODE_SYNC;

View File

@ -721,6 +721,17 @@ static int ext4_ioctl_check_project(struct inode *inode, struct fsxattr *fa)
return 0;
}
static void ext4_fill_fsxattr(struct inode *inode, struct fsxattr *fa)
{
struct ext4_inode_info *ei = EXT4_I(inode);
simple_fill_fsxattr(fa, ext4_iflags_to_xflags(ei->i_flags &
EXT4_FL_USER_VISIBLE));
if (ext4_has_feature_project(inode->i_sb))
fa->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid);
}
long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
@ -1089,13 +1100,7 @@ resizefs_out:
{
struct fsxattr fa;
memset(&fa, 0, sizeof(struct fsxattr));
fa.fsx_xflags = ext4_iflags_to_xflags(ei->i_flags & EXT4_FL_USER_VISIBLE);
if (ext4_has_feature_project(inode->i_sb)) {
fa.fsx_projid = (__u32)from_kprojid(&init_user_ns,
EXT4_I(inode)->i_projid);
}
ext4_fill_fsxattr(inode, &fa);
if (copy_to_user((struct fsxattr __user *)arg,
&fa, sizeof(fa)))
@ -1104,7 +1109,7 @@ resizefs_out:
}
case EXT4_IOC_FSSETXATTR:
{
struct fsxattr fa;
struct fsxattr fa, old_fa;
int err;
if (copy_from_user(&fa, (struct fsxattr __user *)arg,
@ -1127,7 +1132,11 @@ resizefs_out:
return err;
inode_lock(inode);
ext4_fill_fsxattr(inode, &old_fa);
err = ext4_ioctl_check_project(inode, &fa);
if (err)
goto out;
err = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
if (err)
goto out;
flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) |

View File

@ -2194,3 +2194,26 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags,
return 0;
}
EXPORT_SYMBOL(vfs_ioc_setflags_prepare);
/*
* Generic function to check FS_IOC_FSSETXATTR values and reject any invalid
* configurations.
*
* Note: the caller should be holding i_mutex, or else be sure that they have
* exclusive access to the inode structure.
*/
int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa,
struct fsxattr *fa)
{
/*
* Can't modify an immutable/append-only file unless we have
* appropriate permission.
*/
if ((old_fa->fsx_xflags ^ fa->fsx_xflags) &
(FS_XFLAG_IMMUTABLE | FS_XFLAG_APPEND) &&
!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
return 0;
}
EXPORT_SYMBOL(vfs_ioc_fssetxattr_check);

View File

@ -879,6 +879,34 @@ xfs_di2lxflags(
return flags;
}
static void
xfs_fill_fsxattr(
struct xfs_inode *ip,
bool attr,
struct fsxattr *fa)
{
simple_fill_fsxattr(fa, xfs_ip2xflags(ip));
fa->fsx_extsize = ip->i_d.di_extsize << ip->i_mount->m_sb.sb_blocklog;
fa->fsx_cowextsize = ip->i_d.di_cowextsize <<
ip->i_mount->m_sb.sb_blocklog;
fa->fsx_projid = xfs_get_projid(ip);
if (attr) {
if (ip->i_afp) {
if (ip->i_afp->if_flags & XFS_IFEXTENTS)
fa->fsx_nextents = xfs_iext_count(ip->i_afp);
else
fa->fsx_nextents = ip->i_d.di_anextents;
} else
fa->fsx_nextents = 0;
} else {
if (ip->i_df.if_flags & XFS_IFEXTENTS)
fa->fsx_nextents = xfs_iext_count(&ip->i_df);
else
fa->fsx_nextents = ip->i_d.di_nextents;
}
}
STATIC int
xfs_ioc_fsgetxattr(
xfs_inode_t *ip,
@ -887,29 +915,8 @@ xfs_ioc_fsgetxattr(
{
struct fsxattr fa;
memset(&fa, 0, sizeof(struct fsxattr));
xfs_ilock(ip, XFS_ILOCK_SHARED);
fa.fsx_xflags = xfs_ip2xflags(ip);
fa.fsx_extsize = ip->i_d.di_extsize << ip->i_mount->m_sb.sb_blocklog;
fa.fsx_cowextsize = ip->i_d.di_cowextsize <<
ip->i_mount->m_sb.sb_blocklog;
fa.fsx_projid = xfs_get_projid(ip);
if (attr) {
if (ip->i_afp) {
if (ip->i_afp->if_flags & XFS_IFEXTENTS)
fa.fsx_nextents = xfs_iext_count(ip->i_afp);
else
fa.fsx_nextents = ip->i_d.di_anextents;
} else
fa.fsx_nextents = 0;
} else {
if (ip->i_df.if_flags & XFS_IFEXTENTS)
fa.fsx_nextents = xfs_iext_count(&ip->i_df);
else
fa.fsx_nextents = ip->i_d.di_nextents;
}
xfs_fill_fsxattr(ip, attr, &fa);
xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (copy_to_user(arg, &fa, sizeof(fa)))
@ -1035,15 +1042,6 @@ xfs_ioctl_setattr_xflags(
if ((fa->fsx_xflags & FS_XFLAG_DAX) && xfs_is_reflink_inode(ip))
return -EINVAL;
/*
* Can't modify an immutable/append-only file unless
* we have appropriate permission.
*/
if (((ip->i_d.di_flags & (XFS_DIFLAG_IMMUTABLE | XFS_DIFLAG_APPEND)) ||
(fa->fsx_xflags & (FS_XFLAG_IMMUTABLE | FS_XFLAG_APPEND))) &&
!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
/* diflags2 only valid for v3 inodes. */
di_flags2 = xfs_flags2diflags2(ip, fa->fsx_xflags);
if (di_flags2 && ip->i_d.di_version < 3)
@ -1323,6 +1321,7 @@ xfs_ioctl_setattr(
xfs_inode_t *ip,
struct fsxattr *fa)
{
struct fsxattr old_fa;
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
struct xfs_dquot *udqp = NULL;
@ -1370,7 +1369,6 @@ xfs_ioctl_setattr(
goto error_free_dquots;
}
if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_PQUOTA_ON(mp) &&
xfs_get_projid(ip) != fa->fsx_projid) {
code = xfs_qm_vop_chown_reserve(tp, ip, udqp, NULL, pdqp,
@ -1379,6 +1377,11 @@ xfs_ioctl_setattr(
goto error_trans_cancel;
}
xfs_fill_fsxattr(ip, false, &old_fa);
code = vfs_ioc_fssetxattr_check(VFS_I(ip), &old_fa, fa);
if (code)
goto error_trans_cancel;
code = xfs_ioctl_setattr_check_extsize(ip, fa);
if (code)
goto error_trans_cancel;
@ -1489,6 +1492,7 @@ xfs_ioc_setxflags(
{
struct xfs_trans *tp;
struct fsxattr fa;
struct fsxattr old_fa;
unsigned int flags;
int join_flags = 0;
int error;
@ -1524,6 +1528,13 @@ xfs_ioc_setxflags(
goto out_drop_write;
}
xfs_fill_fsxattr(ip, false, &old_fa);
error = vfs_ioc_fssetxattr_check(VFS_I(ip), &old_fa, &fa);
if (error) {
xfs_trans_cancel(tp);
goto out_drop_write;
}
error = xfs_ioctl_setattr_xflags(tp, ip, &fa);
if (error) {
xfs_trans_cancel(tp);

View File

@ -3549,4 +3549,13 @@ static inline struct sock *io_uring_get_socket(struct file *file)
int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags,
unsigned int flags);
int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa,
struct fsxattr *fa);
static inline void simple_fill_fsxattr(struct fsxattr *fa, __u32 xflags)
{
memset(fa, 0, sizeof(*fa));
fa->fsx_xflags = xflags;
}
#endif /* _LINUX_FS_H */