xfs: replace xfs_mod_incore_sb_batched
Introduce helper functions for modifying fields in the superblock
into xfs_trans.c, the only caller of xfs_mod_incore_sb_batch(). We
can then use these directly in xfs_trans_unreserve_and_mod_sb() and
so remove another user of the xfs_mode_incore_sb() API without
losing any functionality or scalability of the transaction commit
code..
Based on a patch from Christoph Hellwig.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 4e4bc5a..220ef2c 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -485,6 +485,54 @@
sizeof(sbp->sb_frextents) - 1);
}
+STATIC int
+xfs_sb_mod8(
+ uint8_t *field,
+ int8_t delta)
+{
+ int8_t counter = *field;
+
+ counter += delta;
+ if (counter < 0) {
+ ASSERT(0);
+ return -EINVAL;
+ }
+ *field = counter;
+ return 0;
+}
+
+STATIC int
+xfs_sb_mod32(
+ uint32_t *field,
+ int32_t delta)
+{
+ int32_t counter = *field;
+
+ counter += delta;
+ if (counter < 0) {
+ ASSERT(0);
+ return -EINVAL;
+ }
+ *field = counter;
+ return 0;
+}
+
+STATIC int
+xfs_sb_mod64(
+ uint64_t *field,
+ int64_t delta)
+{
+ int64_t counter = *field;
+
+ counter += delta;
+ if (counter < 0) {
+ ASSERT(0);
+ return -EINVAL;
+ }
+ *field = counter;
+ return 0;
+}
+
/*
* xfs_trans_unreserve_and_mod_sb() is called to release unused reservations
* and apply superblock counter changes to the in-core superblock. The
@@ -492,13 +540,6 @@
* applied to the in-core superblock. The idea is that that has already been
* done.
*
- * This is done efficiently with a single call to xfs_mod_incore_sb_batch().
- * However, we have to ensure that we only modify each superblock field only
- * once because the application of the delta values may not be atomic. That can
- * lead to ENOSPC races occurring if we have two separate modifcations of the
- * free space counter to put back the entire reservation and then take away
- * what we used.
- *
* If we are not logging superblock counters, then the inode allocated/free and
* used block counts are not updated in the on disk superblock. In this case,
* XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we
@@ -506,20 +547,15 @@
*/
void
xfs_trans_unreserve_and_mod_sb(
- xfs_trans_t *tp)
+ struct xfs_trans *tp)
{
- xfs_mod_sb_t msb[9]; /* If you add cases, add entries */
- xfs_mod_sb_t *msbp;
- xfs_mount_t *mp = tp->t_mountp;
- /* REFERENCED */
- int error;
- bool rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
- int64_t blkdelta = 0;
- int64_t rtxdelta = 0;
- int64_t idelta = 0;
- int64_t ifreedelta = 0;
-
- msbp = msb;
+ struct xfs_mount *mp = tp->t_mountp;
+ bool rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
+ int64_t blkdelta = 0;
+ int64_t rtxdelta = 0;
+ int64_t idelta = 0;
+ int64_t ifreedelta = 0;
+ int error;
/* calculate deltas */
if (tp->t_blk_res > 0)
@@ -560,72 +596,90 @@
goto out_undo_icount;
}
+ if (rtxdelta == 0 && !(tp->t_flags & XFS_TRANS_SB_DIRTY))
+ return;
+
/* apply remaining deltas */
+ spin_lock(&mp->m_sb_lock);
if (rtxdelta) {
- error = xfs_mod_frextents(mp, rtxdelta);
+ error = xfs_sb_mod64(&mp->m_sb.sb_frextents, rtxdelta);
if (error)
goto out_undo_ifree;
}
- if (tp->t_flags & XFS_TRANS_SB_DIRTY) {
- if (tp->t_dblocks_delta != 0) {
- msbp->msb_field = XFS_SBS_DBLOCKS;
- msbp->msb_delta = tp->t_dblocks_delta;
- msbp++;
- }
- if (tp->t_agcount_delta != 0) {
- msbp->msb_field = XFS_SBS_AGCOUNT;
- msbp->msb_delta = tp->t_agcount_delta;
- msbp++;
- }
- if (tp->t_imaxpct_delta != 0) {
- msbp->msb_field = XFS_SBS_IMAX_PCT;
- msbp->msb_delta = tp->t_imaxpct_delta;
- msbp++;
- }
- if (tp->t_rextsize_delta != 0) {
- msbp->msb_field = XFS_SBS_REXTSIZE;
- msbp->msb_delta = tp->t_rextsize_delta;
- msbp++;
- }
- if (tp->t_rbmblocks_delta != 0) {
- msbp->msb_field = XFS_SBS_RBMBLOCKS;
- msbp->msb_delta = tp->t_rbmblocks_delta;
- msbp++;
- }
- if (tp->t_rblocks_delta != 0) {
- msbp->msb_field = XFS_SBS_RBLOCKS;
- msbp->msb_delta = tp->t_rblocks_delta;
- msbp++;
- }
- if (tp->t_rextents_delta != 0) {
- msbp->msb_field = XFS_SBS_REXTENTS;
- msbp->msb_delta = tp->t_rextents_delta;
- msbp++;
- }
- if (tp->t_rextslog_delta != 0) {
- msbp->msb_field = XFS_SBS_REXTSLOG;
- msbp->msb_delta = tp->t_rextslog_delta;
- msbp++;
- }
- }
-
- /*
- * If we need to change anything, do it.
- */
- if (msbp > msb) {
- error = xfs_mod_incore_sb_batch(tp->t_mountp, msb,
- (uint)(msbp - msb), rsvd);
+ if (tp->t_dblocks_delta != 0) {
+ error = xfs_sb_mod64(&mp->m_sb.sb_dblocks, tp->t_dblocks_delta);
if (error)
goto out_undo_frextents;
}
-
+ if (tp->t_agcount_delta != 0) {
+ error = xfs_sb_mod32(&mp->m_sb.sb_agcount, tp->t_agcount_delta);
+ if (error)
+ goto out_undo_dblocks;
+ }
+ if (tp->t_imaxpct_delta != 0) {
+ error = xfs_sb_mod8(&mp->m_sb.sb_imax_pct, tp->t_imaxpct_delta);
+ if (error)
+ goto out_undo_agcount;
+ }
+ if (tp->t_rextsize_delta != 0) {
+ error = xfs_sb_mod32(&mp->m_sb.sb_rextsize,
+ tp->t_rextsize_delta);
+ if (error)
+ goto out_undo_imaxpct;
+ }
+ if (tp->t_rbmblocks_delta != 0) {
+ error = xfs_sb_mod32(&mp->m_sb.sb_rbmblocks,
+ tp->t_rbmblocks_delta);
+ if (error)
+ goto out_undo_rextsize;
+ }
+ if (tp->t_rblocks_delta != 0) {
+ error = xfs_sb_mod64(&mp->m_sb.sb_rblocks, tp->t_rblocks_delta);
+ if (error)
+ goto out_undo_rbmblocks;
+ }
+ if (tp->t_rextents_delta != 0) {
+ error = xfs_sb_mod64(&mp->m_sb.sb_rextents,
+ tp->t_rextents_delta);
+ if (error)
+ goto out_undo_rblocks;
+ }
+ if (tp->t_rextslog_delta != 0) {
+ error = xfs_sb_mod8(&mp->m_sb.sb_rextslog,
+ tp->t_rextslog_delta);
+ if (error)
+ goto out_undo_rextents;
+ }
+ spin_unlock(&mp->m_sb_lock);
return;
+out_undo_rextents:
+ if (tp->t_rextents_delta)
+ xfs_sb_mod64(&mp->m_sb.sb_rextents, -tp->t_rextents_delta);
+out_undo_rblocks:
+ if (tp->t_rblocks_delta)
+ xfs_sb_mod64(&mp->m_sb.sb_rblocks, -tp->t_rblocks_delta);
+out_undo_rbmblocks:
+ if (tp->t_rbmblocks_delta)
+ xfs_sb_mod32(&mp->m_sb.sb_rbmblocks, -tp->t_rbmblocks_delta);
+out_undo_rextsize:
+ if (tp->t_rextsize_delta)
+ xfs_sb_mod32(&mp->m_sb.sb_rextsize, -tp->t_rextsize_delta);
+out_undo_imaxpct:
+ if (tp->t_rextsize_delta)
+ xfs_sb_mod8(&mp->m_sb.sb_imax_pct, -tp->t_imaxpct_delta);
+out_undo_agcount:
+ if (tp->t_agcount_delta)
+ xfs_sb_mod32(&mp->m_sb.sb_agcount, -tp->t_agcount_delta);
+out_undo_dblocks:
+ if (tp->t_dblocks_delta)
+ xfs_sb_mod64(&mp->m_sb.sb_dblocks, -tp->t_dblocks_delta);
out_undo_frextents:
if (rtxdelta)
- xfs_mod_frextents(mp, -rtxdelta);
+ xfs_sb_mod64(&mp->m_sb.sb_frextents, -rtxdelta);
out_undo_ifree:
+ spin_unlock(&mp->m_sb_lock);
if (ifreedelta)
xfs_mod_ifree(mp, -ifreedelta);
out_undo_icount: