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authorChristoph Hellwig <hch@lst.de>2021-08-06 21:05:36 +0300
committerDarrick J. Wong <djwong@kernel.org>2021-08-06 21:05:36 +0300
commit40b52225e58cd3adf9358146b4b39dccfbfe5892 (patch)
treeb568014194623e11cabb0a1feed8bb227d52e455 /fs/xfs/xfs_qm_syscalls.c
parentc500bee1c5b2f1d59b1081ac879d73268ab0ff17 (diff)
downloadlinux-40b52225e58cd3adf9358146b4b39dccfbfe5892.tar.xz
xfs: remove support for disabling quota accounting on a mounted file system
Disabling quota accounting is hairy, racy code with all kinds of pitfalls. And it has a very strange mind set, as quota accounting (unlike enforcement) really is a propery of the on-disk format. There is no good use case for supporting this. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Diffstat (limited to 'fs/xfs/xfs_qm_syscalls.c')
-rw-r--r--fs/xfs/xfs_qm_syscalls.c241
1 files changed, 12 insertions, 229 deletions
diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
index 13a56e1ea15c..d16deb75dc83 100644
--- a/fs/xfs/xfs_qm_syscalls.c
+++ b/fs/xfs/xfs_qm_syscalls.c
@@ -19,91 +19,11 @@
#include "xfs_qm.h"
#include "xfs_icache.h"
-STATIC int
-xfs_qm_log_quotaoff(
- struct xfs_mount *mp,
- struct xfs_qoff_logitem **qoffstartp,
- uint flags)
-{
- struct xfs_trans *tp;
- int error;
- struct xfs_qoff_logitem *qoffi;
-
- error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_quotaoff, 0, 0, 0, &tp);
- if (error)
- goto out;
-
- qoffi = xfs_trans_get_qoff_item(tp, NULL, flags & XFS_ALL_QUOTA_ACCT);
- xfs_trans_log_quotaoff_item(tp, qoffi);
-
- spin_lock(&mp->m_sb_lock);
- mp->m_sb.sb_qflags = (mp->m_qflags & ~(flags)) & XFS_MOUNT_QUOTA_ALL;
- spin_unlock(&mp->m_sb_lock);
-
- xfs_log_sb(tp);
-
- /*
- * We have to make sure that the transaction is secure on disk before we
- * return and actually stop quota accounting. So, make it synchronous.
- * We don't care about quotoff's performance.
- */
- xfs_trans_set_sync(tp);
- error = xfs_trans_commit(tp);
- if (error)
- goto out;
-
- *qoffstartp = qoffi;
-out:
- return error;
-}
-
-STATIC int
-xfs_qm_log_quotaoff_end(
- struct xfs_mount *mp,
- struct xfs_qoff_logitem **startqoff,
- uint flags)
-{
- struct xfs_trans *tp;
- int error;
- struct xfs_qoff_logitem *qoffi;
-
- error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_equotaoff, 0, 0, 0, &tp);
- if (error)
- return error;
-
- qoffi = xfs_trans_get_qoff_item(tp, *startqoff,
- flags & XFS_ALL_QUOTA_ACCT);
- xfs_trans_log_quotaoff_item(tp, qoffi);
- *startqoff = NULL;
-
- /*
- * We have to make sure that the transaction is secure on disk before we
- * return and actually stop quota accounting. So, make it synchronous.
- * We don't care about quotoff's performance.
- */
- xfs_trans_set_sync(tp);
- return xfs_trans_commit(tp);
-}
-
-/*
- * Turn off quota accounting and/or enforcement for all udquots and/or
- * gdquots. Called only at unmount time.
- *
- * This assumes that there are no dquots of this file system cached
- * incore, and modifies the ondisk dquot directly. Therefore, for example,
- * it is an error to call this twice, without purging the cache.
- */
int
xfs_qm_scall_quotaoff(
xfs_mount_t *mp,
uint flags)
{
- struct xfs_quotainfo *q = mp->m_quotainfo;
- uint dqtype;
- int error;
- uint inactivate_flags;
- struct xfs_qoff_logitem *qoffstart = NULL;
-
/*
* No file system can have quotas enabled on disk but not in core.
* Note that quota utilities (like quotaoff) _expect_
@@ -111,160 +31,23 @@ xfs_qm_scall_quotaoff(
*/
if ((mp->m_qflags & flags) == 0)
return -EEXIST;
- error = 0;
-
- flags &= (XFS_ALL_QUOTA_ACCT | XFS_ALL_QUOTA_ENFD);
/*
- * We don't want to deal with two quotaoffs messing up each other,
- * so we're going to serialize it. quotaoff isn't exactly a performance
- * critical thing.
- * If quotaoff, then we must be dealing with the root filesystem.
+ * We do not support actually turning off quota accounting any more.
+ * Just log a warning and ignore the accounting related flags.
*/
- ASSERT(q);
- mutex_lock(&q->qi_quotaofflock);
+ if (flags & XFS_ALL_QUOTA_ACCT)
+ xfs_info(mp, "disabling of quota accounting not supported.");
- /*
- * If we're just turning off quota enforcement, change mp and go.
- */
- if ((flags & XFS_ALL_QUOTA_ACCT) == 0) {
- mp->m_qflags &= ~(flags);
-
- spin_lock(&mp->m_sb_lock);
- mp->m_sb.sb_qflags = mp->m_qflags;
- spin_unlock(&mp->m_sb_lock);
- mutex_unlock(&q->qi_quotaofflock);
-
- /* XXX what to do if error ? Revert back to old vals incore ? */
- return xfs_sync_sb(mp, false);
- }
-
- dqtype = 0;
- inactivate_flags = 0;
- /*
- * If accounting is off, we must turn enforcement off, clear the
- * quota 'CHKD' certificate to make it known that we have to
- * do a quotacheck the next time this quota is turned on.
- */
- if (flags & XFS_UQUOTA_ACCT) {
- dqtype |= XFS_QMOPT_UQUOTA;
- flags |= (XFS_UQUOTA_CHKD | XFS_UQUOTA_ENFD);
- inactivate_flags |= XFS_UQUOTA_ACTIVE;
- }
- if (flags & XFS_GQUOTA_ACCT) {
- dqtype |= XFS_QMOPT_GQUOTA;
- flags |= (XFS_GQUOTA_CHKD | XFS_GQUOTA_ENFD);
- inactivate_flags |= XFS_GQUOTA_ACTIVE;
- }
- if (flags & XFS_PQUOTA_ACCT) {
- dqtype |= XFS_QMOPT_PQUOTA;
- flags |= (XFS_PQUOTA_CHKD | XFS_PQUOTA_ENFD);
- inactivate_flags |= XFS_PQUOTA_ACTIVE;
- }
-
- /*
- * Nothing to do? Don't complain. This happens when we're just
- * turning off quota enforcement.
- */
- if ((mp->m_qflags & flags) == 0)
- goto out_unlock;
-
- /*
- * Write the LI_QUOTAOFF log record, and do SB changes atomically,
- * and synchronously. If we fail to write, we should abort the
- * operation as it cannot be recovered safely if we crash.
- */
- error = xfs_qm_log_quotaoff(mp, &qoffstart, flags);
- if (error)
- goto out_unlock;
-
- /*
- * Next we clear the XFS_MOUNT_*DQ_ACTIVE bit(s) in the mount struct
- * to take care of the race between dqget and quotaoff. We don't take
- * any special locks to reset these bits. All processes need to check
- * these bits *after* taking inode lock(s) to see if the particular
- * quota type is in the process of being turned off. If *ACTIVE, it is
- * guaranteed that all dquot structures and all quotainode ptrs will all
- * stay valid as long as that inode is kept locked.
- *
- * There is no turning back after this.
- */
- mp->m_qflags &= ~inactivate_flags;
-
- /*
- * Give back all the dquot reference(s) held by inodes.
- * Here we go thru every single incore inode in this file system, and
- * do a dqrele on the i_udquot/i_gdquot that it may have.
- * Essentially, as long as somebody has an inode locked, this guarantees
- * that quotas will not be turned off. This is handy because in a
- * transaction once we lock the inode(s) and check for quotaon, we can
- * depend on the quota inodes (and other things) being valid as long as
- * we keep the lock(s).
- */
- error = xfs_dqrele_all_inodes(mp, flags);
- ASSERT(!error);
-
- /*
- * Next we make the changes in the quota flag in the mount struct.
- * This isn't protected by a particular lock directly, because we
- * don't want to take a mrlock every time we depend on quotas being on.
- */
- mp->m_qflags &= ~flags;
-
- /*
- * Go through all the dquots of this file system and purge them,
- * according to what was turned off.
- */
- xfs_qm_dqpurge_all(mp, dqtype);
-
- /*
- * Transactions that had started before ACTIVE state bit was cleared
- * could have logged many dquots, so they'd have higher LSNs than
- * the first QUOTAOFF log record does. If we happen to crash when
- * the tail of the log has gone past the QUOTAOFF record, but
- * before the last dquot modification, those dquots __will__
- * recover, and that's not good.
- *
- * So, we have QUOTAOFF start and end logitems; the start
- * logitem won't get overwritten until the end logitem appears...
- */
- error = xfs_qm_log_quotaoff_end(mp, &qoffstart, flags);
- if (error) {
- /* We're screwed now. Shutdown is the only option. */
- xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
- goto out_unlock;
- }
-
- /*
- * If all quotas are completely turned off, close shop.
- */
- if (mp->m_qflags == 0) {
- mutex_unlock(&q->qi_quotaofflock);
- xfs_qm_destroy_quotainfo(mp);
- return 0;
- }
-
- /*
- * Release our quotainode references if we don't need them anymore.
- */
- if ((dqtype & XFS_QMOPT_UQUOTA) && q->qi_uquotaip) {
- xfs_irele(q->qi_uquotaip);
- q->qi_uquotaip = NULL;
- }
- if ((dqtype & XFS_QMOPT_GQUOTA) && q->qi_gquotaip) {
- xfs_irele(q->qi_gquotaip);
- q->qi_gquotaip = NULL;
- }
- if ((dqtype & XFS_QMOPT_PQUOTA) && q->qi_pquotaip) {
- xfs_irele(q->qi_pquotaip);
- q->qi_pquotaip = NULL;
- }
+ mutex_lock(&mp->m_quotainfo->qi_quotaofflock);
+ mp->m_qflags &= ~(flags & XFS_ALL_QUOTA_ENFD);
+ spin_lock(&mp->m_sb_lock);
+ mp->m_sb.sb_qflags = mp->m_qflags;
+ spin_unlock(&mp->m_sb_lock);
+ mutex_unlock(&mp->m_quotainfo->qi_quotaofflock);
-out_unlock:
- if (error && qoffstart)
- xfs_qm_qoff_logitem_relse(qoffstart);
- mutex_unlock(&q->qi_quotaofflock);
- return error;
+ /* XXX what to do if error ? Revert back to old vals incore ? */
+ return xfs_sync_sb(mp, false);
}
STATIC int