xfs: simplify xfs_qm_dqusage_adjust

There is no need to have the users and group/project quota locked at the
same time.  Get rid of xfs_qm_dqget_noattach and just do a xfs_qm_dqget
inside xfs_qm_quotacheck_dqadjust for the quota we are operating on
right now.  The new version of xfs_qm_quotacheck_dqadjust holds the
inode lock over it's operations, which is not a problem as it simply
increments counters and there is no concern about log contention
during mount time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>

1 files changed, 61 insertions, 142 deletions

diff --git a/fs/xfs/quota/xfs_qm.c b/fs/xfs/quota/xfs_qm.c
index 9a92407109a1..121f632213a7 100644
--- a/fs/xfs/quota/xfs_qm.c
+++ b/fs/xfs/quota/xfs_qm.c
@@ -1199,87 +1199,6 @@ xfs_qm_list_destroy(
         mutex_destroy(&(list->qh_lock));
 }
 
-
-/*
- * Stripped down version of dqattach. This doesn't attach, or even look at the
- * dquots attached to the inode. The rationale is that there won't be any
- * attached at the time this is called from quotacheck.
- */
-STATIC int
-xfs_qm_dqget_noattach(
-        xfs_inode_t     *ip,
-        xfs_dquot_t     **O_udqpp,
-        xfs_dquot_t     **O_gdqpp)
-{
-        int             error;
-        xfs_mount_t     *mp;
-        xfs_dquot_t     *udqp, *gdqp;
-
-        ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
-        mp = ip->i_mount;
-        udqp = NULL;
-        gdqp = NULL;
-
-        if (XFS_IS_UQUOTA_ON(mp)) {
-                ASSERT(ip->i_udquot == NULL);
-                /*
-                 * We want the dquot allocated if it doesn't exist.
-                 */
-                if ((error = xfs_qm_dqget(mp, ip, ip->i_d.di_uid, XFS_DQ_USER,
-                                         XFS_QMOPT_DQALLOC | XFS_QMOPT_DOWARN,
-                                         &udqp))) {
-                        /*
-                         * Shouldn't be able to turn off quotas here.
-                         */
-                        ASSERT(error != ESRCH);
-                        ASSERT(error != ENOENT);
-                        return error;
-                }
-                ASSERT(udqp);
-        }
-
-        if (XFS_IS_OQUOTA_ON(mp)) {
-                ASSERT(ip->i_gdquot == NULL);
-                if (udqp)
-                        xfs_dqunlock(udqp);
-                error = XFS_IS_GQUOTA_ON(mp) ?
-                                xfs_qm_dqget(mp, ip,
-                                             ip->i_d.di_gid, XFS_DQ_GROUP,
-                                             XFS_QMOPT_DQALLOC|XFS_QMOPT_DOWARN,
-                                             &gdqp) :
-                                xfs_qm_dqget(mp, ip,
-                                             ip->i_d.di_projid, XFS_DQ_PROJ,
-                                             XFS_QMOPT_DQALLOC|XFS_QMOPT_DOWARN,
-                                             &gdqp);
-                if (error) {
-                        if (udqp)
-                                xfs_qm_dqrele(udqp);
-                        ASSERT(error != ESRCH);
-                        ASSERT(error != ENOENT);
-                        return error;
-                }
-                ASSERT(gdqp);
-
-                /* Reacquire the locks in the right order */
-                if (udqp) {
-                        if (! xfs_qm_dqlock_nowait(udqp)) {
-                                xfs_dqunlock(gdqp);
-                                xfs_dqlock(udqp);
-                                xfs_dqlock(gdqp);
-                        }
-                }
-        }
-
-        *O_udqpp = udqp;
-        *O_gdqpp = gdqp;
-
-#ifdef QUOTADEBUG
-        if (udqp) ASSERT(XFS_DQ_IS_LOCKED(udqp));
-        if (gdqp) ASSERT(XFS_DQ_IS_LOCKED(gdqp));
-#endif
-        return 0;
-}
-
 /*
  * Create an inode and return with a reference already taken, but unlocked
  * This is how we create quota inodes
@@ -1546,18 +1465,34 @@ xfs_qm_dqiterate(
 
 /*
  * Called by dqusage_adjust in doing a quotacheck.
- * Given the inode, and a dquot (either USR or GRP, doesn't matter),
- * this updates its incore copy as well as the buffer copy. This is
- * so that once the quotacheck is done, we can just log all the buffers,
- * as opposed to logging numerous updates to individual dquots.
+ *
+ * Given the inode, and a dquot id this updates both the incore dqout as well
+ * as the buffer copy. This is so that once the quotacheck is done, we can
+ * just log all the buffers, as opposed to logging numerous updates to
+ * individual dquots.
  */
-STATIC void
+STATIC int
 xfs_qm_quotacheck_dqadjust(
-        xfs_dquot_t             *dqp,
+        struct xfs_inode        *ip,
+        xfs_dqid_t              id,
+        uint                    type,
         xfs_qcnt_t              nblks,
         xfs_qcnt_t              rtblks)
 {
-        ASSERT(XFS_DQ_IS_LOCKED(dqp));
+        struct xfs_mount        *mp = ip->i_mount;
+        struct xfs_dquot        *dqp;
+        int                     error;
+
+        error = xfs_qm_dqget(mp, ip, id, type,
+                             XFS_QMOPT_DQALLOC | XFS_QMOPT_DOWARN, &dqp);
+        if (error) {
+                /*
+                 * Shouldn't be able to turn off quotas here.
+                 */
+                ASSERT(error != ESRCH);
+                ASSERT(error != ENOENT);
+                return error;
+        }
 
         trace_xfs_dqadjust(dqp);
 
@@ -1582,11 +1517,13 @@ xfs_qm_quotacheck_dqadjust(
          * There are no timers for the default values set in the root dquot.
          */
         if (dqp->q_core.d_id) {
-                xfs_qm_adjust_dqlimits(dqp->q_mount, &dqp->q_core);
-                xfs_qm_adjust_dqtimers(dqp->q_mount, &dqp->q_core);
+                xfs_qm_adjust_dqlimits(mp, &dqp->q_core);
+                xfs_qm_adjust_dqtimers(mp, &dqp->q_core);
         }
 
         dqp->dq_flags |= XFS_DQ_DIRTY;
+        xfs_qm_dqput(dqp);
+        return 0;
 }
 
 STATIC int
@@ -1629,8 +1566,7 @@ xfs_qm_dqusage_adjust(
         int             *res)           /* result code value */
 {
         xfs_inode_t     *ip;
-        xfs_dquot_t     *udqp, *gdqp;
-        xfs_qcnt_t      nblks, rtblks;
+        xfs_qcnt_t      nblks, rtblks = 0;
         int             error;
 
         ASSERT(XFS_IS_QUOTA_RUNNING(mp));
@@ -1650,51 +1586,24 @@ xfs_qm_dqusage_adjust(
          * the case in all other instances. It's OK that we do this because
          * quotacheck is done only at mount time.
          */
-        if ((error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_EXCL, &ip))) {
+        error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_EXCL, &ip);
+        if (error) {
                 *res = BULKSTAT_RV_NOTHING;
                 return error;
         }
 
-        /*
-         * Obtain the locked dquots. In case of an error (eg. allocation
-         * fails for ENOSPC), we return the negative of the error number
-         * to bulkstat, so that it can get propagated to quotacheck() and
-         * making us disable quotas for the file system.
-         */
-        if ((error = xfs_qm_dqget_noattach(ip, &udqp, &gdqp))) {
-                xfs_iunlock(ip, XFS_ILOCK_EXCL);
-                IRELE(ip);
-                *res = BULKSTAT_RV_GIVEUP;
-                return error;
-        }
+        ASSERT(ip->i_delayed_blks == 0);
 
-        rtblks = 0;
-        if (! XFS_IS_REALTIME_INODE(ip)) {
-                nblks = (xfs_qcnt_t)ip->i_d.di_nblocks;
-        } else {
+        if (XFS_IS_REALTIME_INODE(ip)) {
                 /*
                  * Walk thru the extent list and count the realtime blocks.
                  */
-                if ((error = xfs_qm_get_rtblks(ip, &rtblks))) {
-                        xfs_iunlock(ip, XFS_ILOCK_EXCL);
-                        IRELE(ip);
-                        if (udqp)
-                                xfs_qm_dqput(udqp);
-                        if (gdqp)
-                                xfs_qm_dqput(gdqp);
-                        *res = BULKSTAT_RV_GIVEUP;
-                        return error;
-                }
-                nblks = (xfs_qcnt_t)ip->i_d.di_nblocks - rtblks;
+                error = xfs_qm_get_rtblks(ip, &rtblks);
+                if (error)
+                        goto error0;
         }
-        ASSERT(ip->i_delayed_blks == 0);
 
-        /*
-         * We can't release the inode while holding its dquot locks.
-         * The inode can go into inactive and might try to acquire the dquotlocks.
-         * So, just unlock here and do a vn_rele at the end.
-         */
-        xfs_iunlock(ip, XFS_ILOCK_EXCL);
+        nblks = (xfs_qcnt_t)ip->i_d.di_nblocks - rtblks;
 
         /*
          * Add the (disk blocks and inode) resources occupied by this
@@ -1709,26 +1618,36 @@ xfs_qm_dqusage_adjust(
          * and quotaoffs don't race. (Quotachecks happen at mount time only).
          */
         if (XFS_IS_UQUOTA_ON(mp)) {
-                ASSERT(udqp);
-                xfs_qm_quotacheck_dqadjust(udqp, nblks, rtblks);
-                xfs_qm_dqput(udqp);
+                error = xfs_qm_quotacheck_dqadjust(ip, ip->i_d.di_uid,
+                                                   XFS_DQ_USER, nblks, rtblks);
+                if (error)
+                        goto error0;
         }
-        if (XFS_IS_OQUOTA_ON(mp)) {
-                ASSERT(gdqp);
-                xfs_qm_quotacheck_dqadjust(gdqp, nblks, rtblks);
-                xfs_qm_dqput(gdqp);
+
+        if (XFS_IS_GQUOTA_ON(mp)) {
+                error = xfs_qm_quotacheck_dqadjust(ip, ip->i_d.di_gid,
+                                                   XFS_DQ_GROUP, nblks, rtblks);
+                if (error)
+                        goto error0;
         }
-        /*
-         * Now release the inode. This will send it to 'inactive', and
-         * possibly even free blocks.
-         */
-        IRELE(ip);
 
-        /*
-         * Goto next inode.
-         */
+        if (XFS_IS_PQUOTA_ON(mp)) {
+                error = xfs_qm_quotacheck_dqadjust(ip, ip->i_d.di_projid,
+                                                   XFS_DQ_PROJ, nblks, rtblks);
+                if (error)
+                        goto error0;
+        }
+
+        xfs_iunlock(ip, XFS_ILOCK_EXCL);
+        IRELE(ip);
         *res = BULKSTAT_RV_DIDONE;
         return 0;
+
+error0:
+        xfs_iunlock(ip, XFS_ILOCK_EXCL);
+        IRELE(ip);
+        *res = BULKSTAT_RV_GIVEUP;
+        return error;
 }
 
 /*