vfs: create a generic checking and prep function for FS_IOC_SETFLAGS

Create a generic function to check incoming FS_IOC_SETFLAGS flag values
and later prepare the inode for updates so that we can standardize the
implementations that follow ext4's flag values.

Note that the efivarfs implementation no longer fails a no-op SETFLAGS
without CAP_LINUX_IMMUTABLE since that's the behavior in ext*.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
This commit is contained in:
Darrick J. Wong 2019-07-01 08:25:34 -07:00
parent d1fdb6d8f6
commit 5aca284210
14 changed files with 144 additions and 118 deletions

View File

@ -187,7 +187,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
struct btrfs_inode *binode = BTRFS_I(inode);
struct btrfs_root *root = binode->root;
struct btrfs_trans_handle *trans;
unsigned int fsflags;
unsigned int fsflags, old_fsflags;
int ret;
const char *comp = NULL;
u32 binode_flags = binode->flags;
@ -212,13 +212,10 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
inode_lock(inode);
fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
if ((fsflags ^ btrfs_inode_flags_to_fsflags(binode->flags)) &
(FS_APPEND_FL | FS_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
ret = -EPERM;
goto out_unlock;
}
}
old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
ret = vfs_ioc_setflags_prepare(inode, old_fsflags, fsflags);
if (ret)
goto out_unlock;
if (fsflags & FS_SYNC_FL)
binode_flags |= BTRFS_INODE_SYNC;

View File

@ -110,16 +110,22 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
return size;
}
static int
efivarfs_ioc_getxflags(struct file *file, void __user *arg)
static inline unsigned int efivarfs_getflags(struct inode *inode)
{
struct inode *inode = file->f_mapping->host;
unsigned int i_flags;
unsigned int flags = 0;
i_flags = inode->i_flags;
if (i_flags & S_IMMUTABLE)
flags |= FS_IMMUTABLE_FL;
return flags;
}
static int
efivarfs_ioc_getxflags(struct file *file, void __user *arg)
{
struct inode *inode = file->f_mapping->host;
unsigned int flags = efivarfs_getflags(inode);
if (copy_to_user(arg, &flags, sizeof(flags)))
return -EFAULT;
@ -132,6 +138,7 @@ efivarfs_ioc_setxflags(struct file *file, void __user *arg)
struct inode *inode = file->f_mapping->host;
unsigned int flags;
unsigned int i_flags = 0;
unsigned int oldflags = efivarfs_getflags(inode);
int error;
if (!inode_owner_or_capable(inode))
@ -143,9 +150,6 @@ efivarfs_ioc_setxflags(struct file *file, void __user *arg)
if (flags & ~FS_IMMUTABLE_FL)
return -EOPNOTSUPP;
if (!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
if (flags & FS_IMMUTABLE_FL)
i_flags |= S_IMMUTABLE;
@ -155,12 +159,16 @@ efivarfs_ioc_setxflags(struct file *file, void __user *arg)
return error;
inode_lock(inode);
error = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (error)
goto out;
inode_set_flags(inode, i_flags, S_IMMUTABLE);
out:
inode_unlock(inode);
mnt_drop_write_file(file);
return 0;
return error;
}
static long

View File

@ -60,18 +60,10 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
}
oldflags = ei->i_flags;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*
* This test looks nicer. Thanks to Pauline Middelink
*/
if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
inode_unlock(inode);
ret = -EPERM;
goto setflags_out;
}
ret = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (ret) {
inode_unlock(inode);
goto setflags_out;
}
flags = flags & EXT2_FL_USER_MODIFIABLE;

View File

@ -289,16 +289,9 @@ static int ext4_ioctl_setflags(struct inode *inode,
/* The JOURNAL_DATA flag is modifiable only by root */
jflag = flags & EXT4_JOURNAL_DATA_FL;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*
* This test looks nicer. Thanks to Pauline Middelink
*/
if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE))
goto flags_out;
}
err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (err)
goto flags_out;
/*
* The JOURNAL_DATA flag can only be changed by

View File

@ -136,27 +136,36 @@ static struct {
{FS_JOURNAL_DATA_FL, GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA},
};
static inline u32 gfs2_gfsflags_to_fsflags(struct inode *inode, u32 gfsflags)
{
int i;
u32 fsflags = 0;
if (S_ISDIR(inode->i_mode))
gfsflags &= ~GFS2_DIF_JDATA;
else
gfsflags &= ~GFS2_DIF_INHERIT_JDATA;
for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++)
if (gfsflags & fsflag_gfs2flag[i].gfsflag)
fsflags |= fsflag_gfs2flag[i].fsflag;
return fsflags;
}
static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
{
struct inode *inode = file_inode(filp);
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
int i, error;
u32 gfsflags, fsflags = 0;
int error;
u32 fsflags;
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
error = gfs2_glock_nq(&gh);
if (error)
goto out_uninit;
gfsflags = ip->i_diskflags;
if (S_ISDIR(inode->i_mode))
gfsflags &= ~GFS2_DIF_JDATA;
else
gfsflags &= ~GFS2_DIF_INHERIT_JDATA;
for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++)
if (gfsflags & fsflag_gfs2flag[i].gfsflag)
fsflags |= fsflag_gfs2flag[i].fsflag;
fsflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags);
if (put_user(fsflags, ptr))
error = -EFAULT;
@ -200,9 +209,11 @@ void gfs2_set_inode_flags(struct inode *inode)
* @filp: file pointer
* @reqflags: The flags to set
* @mask: Indicates which flags are valid
* @fsflags: The FS_* inode flags passed in
*
*/
static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask,
const u32 fsflags)
{
struct inode *inode = file_inode(filp);
struct gfs2_inode *ip = GFS2_I(inode);
@ -210,7 +221,7 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
struct buffer_head *bh;
struct gfs2_holder gh;
int error;
u32 new_flags, flags;
u32 new_flags, flags, oldflags;
error = mnt_want_write_file(filp);
if (error)
@ -220,6 +231,11 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
if (error)
goto out_drop_write;
oldflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags);
error = vfs_ioc_setflags_prepare(inode, oldflags, fsflags);
if (error)
goto out;
error = -EACCES;
if (!inode_owner_or_capable(inode))
goto out;
@ -308,7 +324,7 @@ static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
mask &= ~(GFS2_DIF_TOPDIR | GFS2_DIF_INHERIT_JDATA);
}
return do_gfs2_set_flags(filp, gfsflags, mask);
return do_gfs2_set_flags(filp, gfsflags, mask, fsflags);
}
static int gfs2_getlabel(struct file *filp, char __user *label)

View File

@ -57,9 +57,8 @@ static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
return 0;
}
static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
static inline unsigned int hfsplus_getflags(struct inode *inode)
{
struct inode *inode = file_inode(file);
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
unsigned int flags = 0;
@ -69,6 +68,13 @@ static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
flags |= FS_APPEND_FL;
if (hip->userflags & HFSPLUS_FLG_NODUMP)
flags |= FS_NODUMP_FL;
return flags;
}
static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
{
struct inode *inode = file_inode(file);
unsigned int flags = hfsplus_getflags(inode);
return put_user(flags, user_flags);
}
@ -78,6 +84,7 @@ static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
struct inode *inode = file_inode(file);
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
unsigned int flags, new_fl = 0;
unsigned int oldflags = hfsplus_getflags(inode);
int err = 0;
err = mnt_want_write_file(file);
@ -96,13 +103,9 @@ static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
inode_lock(inode);
if ((flags & (FS_IMMUTABLE_FL|FS_APPEND_FL)) ||
inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
err = -EPERM;
goto out_unlock_inode;
}
}
err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (err)
goto out_unlock_inode;
/* don't silently ignore unsupported ext2 flags */
if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {

View File

@ -2170,3 +2170,27 @@ struct timespec64 current_time(struct inode *inode)
return timespec64_trunc(now, inode->i_sb->s_time_gran);
}
EXPORT_SYMBOL(current_time);
/*
* Generic function to check FS_IOC_SETFLAGS 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_setflags_prepare(struct inode *inode, unsigned int oldflags,
unsigned int flags)
{
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*
* This test looks nicer. Thanks to Pauline Middelink
*/
if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL) &&
!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
return 0;
}
EXPORT_SYMBOL(vfs_ioc_setflags_prepare);

View File

@ -98,24 +98,16 @@ long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
/* Lock against other parallel changes of flags */
inode_lock(inode);
oldflags = jfs_inode->mode2;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*/
if ((oldflags & JFS_IMMUTABLE_FL) ||
((flags ^ oldflags) &
(JFS_APPEND_FL | JFS_IMMUTABLE_FL))) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
inode_unlock(inode);
err = -EPERM;
goto setflags_out;
}
oldflags = jfs_map_ext2(jfs_inode->mode2 & JFS_FL_USER_VISIBLE,
0);
err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (err) {
inode_unlock(inode);
goto setflags_out;
}
flags = flags & JFS_FL_USER_MODIFIABLE;
flags |= oldflags & ~JFS_FL_USER_MODIFIABLE;
flags |= jfs_inode->mode2 & ~JFS_FL_USER_MODIFIABLE;
jfs_inode->mode2 = flags;
jfs_set_inode_flags(inode);

View File

@ -148,13 +148,8 @@ static int nilfs_ioctl_setflags(struct inode *inode, struct file *filp,
oldflags = NILFS_I(inode)->i_flags;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by the
* relevant capability.
*/
ret = -EPERM;
if (((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) &&
!capable(CAP_LINUX_IMMUTABLE))
ret = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (ret)
goto out;
ret = nilfs_transaction_begin(inode->i_sb, &ti, 0);

View File

@ -106,16 +106,9 @@ static int ocfs2_set_inode_attr(struct inode *inode, unsigned flags,
flags = flags & mask;
flags |= oldflags & ~mask;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*/
status = -EPERM;
if ((oldflags & OCFS2_IMMUTABLE_FL) || ((flags ^ oldflags) &
(OCFS2_APPEND_FL | OCFS2_IMMUTABLE_FL))) {
if (!capable(CAP_LINUX_IMMUTABLE))
goto bail_unlock;
}
status = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (status)
goto bail_unlock;
handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
if (IS_ERR(handle)) {

View File

@ -357,11 +357,28 @@ static ssize_t orangefs_file_write_iter(struct kiocb *iocb,
return ret;
}
static int orangefs_getflags(struct inode *inode, unsigned long *uval)
{
__u64 val = 0;
int ret;
ret = orangefs_inode_getxattr(inode,
"user.pvfs2.meta_hint",
&val, sizeof(val));
if (ret < 0 && ret != -ENODATA)
return ret;
else if (ret == -ENODATA)
val = 0;
*uval = val;
return 0;
}
/*
* Perform a miscellaneous operation on a file.
*/
static long orangefs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(file);
int ret = -ENOTTY;
__u64 val = 0;
unsigned long uval;
@ -375,20 +392,16 @@ static long orangefs_ioctl(struct file *file, unsigned int cmd, unsigned long ar
* and append flags
*/
if (cmd == FS_IOC_GETFLAGS) {
val = 0;
ret = orangefs_inode_getxattr(file_inode(file),
"user.pvfs2.meta_hint",
&val, sizeof(val));
if (ret < 0 && ret != -ENODATA)
ret = orangefs_getflags(inode, &uval);
if (ret)
return ret;
else if (ret == -ENODATA)
val = 0;
uval = val;
gossip_debug(GOSSIP_FILE_DEBUG,
"orangefs_ioctl: FS_IOC_GETFLAGS: %llu\n",
(unsigned long long)uval);
return put_user(uval, (int __user *)arg);
} else if (cmd == FS_IOC_SETFLAGS) {
unsigned long old_uval;
ret = 0;
if (get_user(uval, (int __user *)arg))
return -EFAULT;
@ -404,11 +417,17 @@ static long orangefs_ioctl(struct file *file, unsigned int cmd, unsigned long ar
gossip_err("orangefs_ioctl: the FS_IOC_SETFLAGS only supports setting one of FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NOATIME_FL\n");
return -EINVAL;
}
ret = orangefs_getflags(inode, &old_uval);
if (ret)
return ret;
ret = vfs_ioc_setflags_prepare(inode, old_uval, uval);
if (ret)
return ret;
val = uval;
gossip_debug(GOSSIP_FILE_DEBUG,
"orangefs_ioctl: FS_IOC_SETFLAGS: %llu\n",
(unsigned long long)val);
ret = orangefs_inode_setxattr(file_inode(file),
ret = orangefs_inode_setxattr(inode,
"user.pvfs2.meta_hint",
&val, sizeof(val), 0);
}

View File

@ -74,13 +74,11 @@ long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
err = -EPERM;
goto setflags_out;
}
if (((flags ^ REISERFS_I(inode)->
i_attrs) & (REISERFS_IMMUTABLE_FL |
REISERFS_APPEND_FL))
&& !capable(CAP_LINUX_IMMUTABLE)) {
err = -EPERM;
err = vfs_ioc_setflags_prepare(inode,
REISERFS_I(inode)->i_attrs,
flags);
if (err)
goto setflags_out;
}
if ((flags & REISERFS_NOTAIL_FL) &&
S_ISREG(inode->i_mode)) {
int result;

View File

@ -107,18 +107,11 @@ static int setflags(struct inode *inode, int flags)
if (err)
return err;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*/
mutex_lock(&ui->ui_mutex);
oldflags = ubifs2ioctl(ui->flags);
if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
err = -EPERM;
goto out_unlock;
}
}
err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (err)
goto out_unlock;
ui->flags = ioctl2ubifs(flags);
ubifs_set_inode_flags(inode);

View File

@ -3546,4 +3546,7 @@ static inline struct sock *io_uring_get_socket(struct file *file)
}
#endif
int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags,
unsigned int flags);
#endif /* _LINUX_FS_H */