Implement File Attribute Support

We add support for lsattr and chattr to resolve a regression caused
by 88c283952f that broke Python's
xattr.list(). That changet broke Gentoo Portage's FEATURES=xattr,
which depended on Python's xattr.list().

Only attributes common to both Solaris and Linux are supported. These
are 'a', 'd' and 'i' in Linux's lsattr and chattr commands. File
attributes exclusive to Solaris are present in the ZFS code, but cannot
be accessed or modified through this method.  That was the case prior to
this patch. The resolution of issue zfsonlinux/zfs#229 should implement
some method to permit access and modification of Solaris-specific
attributes.

References:
  https://bugs.gentoo.org/show_bug.cgi?id=483516

Original-patch-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1691
This commit is contained in:
Richard Yao 2011-07-01 15:56:35 -07:00 committed by Brian Behlendorf
parent 3b4f425a5a
commit 9d317793aa
3 changed files with 114 additions and 6 deletions

View File

@ -152,9 +152,6 @@ typedef int zpl_umode_t;
#define zpl_sget(type, cmp, set, fl, mtd) sget(type, cmp, set, mtd)
#endif /* HAVE_5ARG_SGET */
#define ZFS_IOC_GETFLAGS FS_IOC_GETFLAGS
#define ZFS_IOC_SETFLAGS FS_IOC_SETFLAGS
#if defined(SEEK_HOLE) && defined(SEEK_DATA) && !defined(HAVE_LSEEK_EXECUTE)
static inline loff_t
lseek_execute(

View File

@ -446,6 +446,25 @@ error:
return (NULL);
}
void
zfs_set_inode_flags(znode_t *zp, struct inode *ip)
{
/*
* Linux and Solaris have different sets of file attributes, so we
* restrict this conversion to the intersection of the two.
*/
if (zp->z_pflags & ZFS_IMMUTABLE)
ip->i_flags |= S_IMMUTABLE;
else
ip->i_flags &= ~S_IMMUTABLE;
if (zp->z_pflags & ZFS_APPENDONLY)
ip->i_flags |= S_APPEND;
else
ip->i_flags &= ~S_APPEND;
}
/*
* Update the embedded inode given the znode. We should work toward
* eliminating this function as soon as possible by removing values
@ -479,6 +498,7 @@ zfs_inode_update(znode_t *zp)
ip->i_gid = SGID_TO_KGID(zp->z_gid);
set_nlink(ip, zp->z_links);
ip->i_mode = zp->z_mode;
zfs_set_inode_flags(zp, ip);
ip->i_blkbits = SPA_MINBLOCKSHIFT;
dmu_object_size_from_db(sa_get_db(zp->z_sa_hdl), &blksize,
(u_longlong_t *)&ip->i_blocks);

View File

@ -520,13 +520,104 @@ zpl_fallocate(struct file *filp, int mode, loff_t offset, loff_t len)
}
#endif /* HAVE_FILE_FALLOCATE */
/*
* Map zfs file z_pflags (xvattr_t) to linux file attributes. Only file
* attributes common to both Linux and Solaris are mapped.
*/
static int
zpl_ioctl_getflags(struct file *filp, void __user *arg)
{
struct inode *ip = filp->f_dentry->d_inode;
unsigned int ioctl_flags = 0;
uint64_t zfs_flags = ITOZ(ip)->z_pflags;
int error;
if (zfs_flags & ZFS_IMMUTABLE)
ioctl_flags |= FS_IMMUTABLE_FL;
if (zfs_flags & ZFS_APPENDONLY)
ioctl_flags |= FS_APPEND_FL;
if (zfs_flags & ZFS_NODUMP)
ioctl_flags |= FS_NODUMP_FL;
ioctl_flags &= FS_FL_USER_VISIBLE;
error = copy_to_user(arg, &ioctl_flags, sizeof (ioctl_flags));
return (error);
}
/*
* fchange() is a helper macro to detect if we have been asked to change a
* flag. This is ugly, but the requirement that we do this is a consequence of
* how the Linux file attribute interface was designed. Another consequence is
* that concurrent modification of files suffers from a TOCTOU race. Neither
* are things we can fix without modifying the kernel-userland interface, which
* is outside of our jurisdiction.
*/
#define fchange(f0, f1, b0, b1) ((((f0) & (b0)) == (b0)) != \
(((b1) & (f1)) == (f1)))
static int
zpl_ioctl_setflags(struct file *filp, void __user *arg)
{
struct inode *ip = filp->f_dentry->d_inode;
uint64_t zfs_flags = ITOZ(ip)->z_pflags;
unsigned int ioctl_flags;
cred_t *cr = CRED();
xvattr_t xva;
xoptattr_t *xoap;
int error;
if (copy_from_user(&ioctl_flags, arg, sizeof (ioctl_flags)))
return (-EFAULT);
if ((ioctl_flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL)))
return (-EOPNOTSUPP);
if ((ioctl_flags & ~(FS_FL_USER_MODIFIABLE)))
return (-EACCES);
if ((fchange(ioctl_flags, zfs_flags, FS_IMMUTABLE_FL, ZFS_IMMUTABLE) ||
fchange(ioctl_flags, zfs_flags, FS_APPEND_FL, ZFS_APPENDONLY)) &&
!capable(CAP_LINUX_IMMUTABLE))
return (-EACCES);
if (!zpl_inode_owner_or_capable(ip))
return (-EACCES);
xva_init(&xva);
xoap = xva_getxoptattr(&xva);
XVA_SET_REQ(&xva, XAT_IMMUTABLE);
if (ioctl_flags & FS_IMMUTABLE_FL)
xoap->xoa_immutable = B_TRUE;
XVA_SET_REQ(&xva, XAT_APPENDONLY);
if (ioctl_flags & FS_APPEND_FL)
xoap->xoa_appendonly = B_TRUE;
XVA_SET_REQ(&xva, XAT_NODUMP);
if (ioctl_flags & FS_NODUMP_FL)
xoap->xoa_nodump = B_TRUE;
crhold(cr);
error = -zfs_setattr(ip, (vattr_t *)&xva, 0, cr);
crfree(cr);
return (error);
}
static long
zpl_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case ZFS_IOC_GETFLAGS:
case ZFS_IOC_SETFLAGS:
return (-EOPNOTSUPP);
case FS_IOC_GETFLAGS:
return (zpl_ioctl_getflags(filp, (void *)arg));
case FS_IOC_SETFLAGS:
return (zpl_ioctl_setflags(filp, (void *)arg));
default:
return (-ENOTTY);
}