xfs: refactor inode ownership change transaction/inode/quota allocation idiom

For file ownership (uid, gid, prid) changes, create a new helper
xfs_trans_alloc_ichange that allocates a transaction and reserves the
appropriate amount of quota against that transction in preparation for a
change of user, group, or project id.  Replace all the open-coded idioms
with a single call to this helper so that we can contain the retry loops
in the next patchset.

This changes the locking behavior for ichange transactions slightly.
Since tr_ichange does not have a permanent reservation and cannot roll,
we pass XFS_ILOCK_EXCL to ijoin so that the inode will be unlocked
automatically at commit time.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Darrick J. Wong 2021-01-29 11:32:09 -08:00
parent f2f7b9ff62
commit 7317a03df7
4 changed files with 77 additions and 43 deletions

View File

@ -1275,24 +1275,23 @@ xfs_ioctl_setattr_prepare_dax(
*/
static struct xfs_trans *
xfs_ioctl_setattr_get_trans(
struct xfs_inode *ip)
struct xfs_inode *ip,
struct xfs_dquot *pdqp)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
int error = -EROFS;
if (mp->m_flags & XFS_MOUNT_RDONLY)
goto out_unlock;
goto out_error;
error = -EIO;
if (XFS_FORCED_SHUTDOWN(mp))
goto out_unlock;
goto out_error;
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
error = xfs_trans_alloc_ichange(ip, NULL, NULL, pdqp,
capable(CAP_FOWNER), &tp);
if (error)
goto out_unlock;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
goto out_error;
/*
* CAP_FOWNER overrides the following restrictions:
@ -1312,7 +1311,7 @@ xfs_ioctl_setattr_get_trans(
out_cancel:
xfs_trans_cancel(tp);
out_unlock:
out_error:
return ERR_PTR(error);
}
@ -1462,20 +1461,12 @@ xfs_ioctl_setattr(
xfs_ioctl_setattr_prepare_dax(ip, fa);
tp = xfs_ioctl_setattr_get_trans(ip);
tp = xfs_ioctl_setattr_get_trans(ip, pdqp);
if (IS_ERR(tp)) {
code = PTR_ERR(tp);
goto error_free_dquots;
}
if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_PQUOTA_ON(mp) &&
ip->i_d.di_projid != fa->fsx_projid) {
code = xfs_qm_vop_chown_reserve(tp, ip, NULL, NULL, pdqp,
capable(CAP_FOWNER) ? XFS_QMOPT_FORCE_RES : 0);
if (code) /* out of quota */
goto error_trans_cancel;
}
xfs_fill_fsxattr(ip, false, &old_fa);
code = vfs_ioc_fssetxattr_check(VFS_I(ip), &old_fa, fa);
if (code)
@ -1608,7 +1599,7 @@ xfs_ioc_setxflags(
xfs_ioctl_setattr_prepare_dax(ip, &fa);
tp = xfs_ioctl_setattr_get_trans(ip);
tp = xfs_ioctl_setattr_get_trans(ip, NULL);
if (IS_ERR(tp)) {
error = PTR_ERR(tp);
goto out_drop_write;

View File

@ -700,13 +700,11 @@ xfs_setattr_nonsize(
return error;
}
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
error = xfs_trans_alloc_ichange(ip, udqp, gdqp, NULL,
capable(CAP_FOWNER), &tp);
if (error)
goto out_dqrele;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);
/*
* Change file ownership. Must be the owner or privileged.
*/
@ -722,21 +720,6 @@ xfs_setattr_nonsize(
gid = (mask & ATTR_GID) ? iattr->ia_gid : igid;
uid = (mask & ATTR_UID) ? iattr->ia_uid : iuid;
/*
* Do a quota reservation only if uid/gid is actually
* going to change.
*/
if (XFS_IS_QUOTA_RUNNING(mp) &&
((XFS_IS_UQUOTA_ON(mp) && !uid_eq(iuid, uid)) ||
(XFS_IS_GQUOTA_ON(mp) && !gid_eq(igid, gid)))) {
ASSERT(tp);
error = xfs_qm_vop_chown_reserve(tp, ip, udqp, gdqp,
NULL, capable(CAP_FOWNER) ?
XFS_QMOPT_FORCE_RES : 0);
if (error) /* out of quota */
goto out_cancel;
}
/*
* CAP_FSETID overrides the following restrictions:
*
@ -786,8 +769,6 @@ xfs_setattr_nonsize(
xfs_trans_set_sync(tp);
error = xfs_trans_commit(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
/*
* Release any dquot(s) the inode had kept before chown.
*/
@ -814,9 +795,6 @@ xfs_setattr_nonsize(
return 0;
out_cancel:
xfs_trans_cancel(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
out_dqrele:
xfs_qm_dqrele(udqp);
xfs_qm_dqrele(gdqp);

View File

@ -1107,3 +1107,65 @@ xfs_trans_alloc_icreate(
*tpp = tp;
return 0;
}
/*
* Allocate an transaction, lock and join the inode to it, and reserve quota
* in preparation for inode attribute changes that include uid, gid, or prid
* changes.
*
* The caller must ensure that the on-disk dquots attached to this inode have
* already been allocated and initialized. The ILOCK will be dropped when the
* transaction is committed or cancelled.
*/
int
xfs_trans_alloc_ichange(
struct xfs_inode *ip,
struct xfs_dquot *udqp,
struct xfs_dquot *gdqp,
struct xfs_dquot *pdqp,
bool force,
struct xfs_trans **tpp)
{
struct xfs_trans *tp;
struct xfs_mount *mp = ip->i_mount;
int error;
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
if (error)
return error;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
error = xfs_qm_dqattach_locked(ip, false);
if (error) {
/* Caller should have allocated the dquots! */
ASSERT(error != -ENOENT);
goto out_cancel;
}
/*
* For each quota type, skip quota reservations if the inode's dquots
* now match the ones that came from the caller, or the caller didn't
* pass one in.
*/
if (udqp == ip->i_udquot)
udqp = NULL;
if (gdqp == ip->i_gdquot)
gdqp = NULL;
if (pdqp == ip->i_pdquot)
pdqp = NULL;
if (udqp || gdqp || pdqp) {
error = xfs_qm_vop_chown_reserve(tp, ip, udqp, gdqp, pdqp,
force ? XFS_QMOPT_FORCE_RES : 0);
if (error)
goto out_cancel;
}
*tpp = tp;
return 0;
out_cancel:
xfs_trans_cancel(tp);
return error;
}

View File

@ -277,5 +277,8 @@ int xfs_trans_alloc_icreate(struct xfs_mount *mp, struct xfs_trans_res *resv,
struct xfs_dquot *udqp, struct xfs_dquot *gdqp,
struct xfs_dquot *pdqp, unsigned int dblocks,
struct xfs_trans **tpp);
int xfs_trans_alloc_ichange(struct xfs_inode *ip, struct xfs_dquot *udqp,
struct xfs_dquot *gdqp, struct xfs_dquot *pdqp, bool force,
struct xfs_trans **tpp);
#endif /* __XFS_TRANS_H__ */