From: Dave Chinner david@fromorbit.com
[ Upstream commit dc3ffbb14060c943469d5e12900db3a60bc3fa64 ]
xfs: gut error handling in xfs_trans_unreserve_and_mod_sb()
From: Dave Chinner dchinner@redhat.com
The error handling in xfs_trans_unreserve_and_mod_sb() is largely incorrect - rolling back the changes in the transaction if only one counter underruns makes all the other counters incorrect. We still allow the change to proceed and committing the transaction, except now we have multiple incorrect counters instead of a single underflow.
Further, we don't actually report the error to the caller, so this is completely silent except on debug kernels that will assert on failure before we even get to the rollback code. Hence this error handling is broken, untested, and largely unnecessary complexity.
Just remove it.
Signed-off-by: Dave Chinner dchinner@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/xfs/xfs_trans.c | 163 ++++++--------------------------------------- 1 file changed, 20 insertions(+), 143 deletions(-)
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index a87f657f59c9..cad4b04e31a7 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -493,57 +493,9 @@ xfs_trans_apply_sb_deltas( 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 + * xfs_trans_unreserve_and_mod_sb() is called to release unused reservations and + * apply superblock counter changes to the in-core superblock. The * t_res_fdblocks_delta and t_res_frextents_delta fields are explicitly NOT * applied to the in-core superblock. The idea is that that has already been * done. @@ -588,20 +540,17 @@ xfs_trans_unreserve_and_mod_sb( /* apply the per-cpu counters */ if (blkdelta) { error = xfs_mod_fdblocks(mp, blkdelta, rsvd); - if (error) - goto out; + ASSERT(!error); }
if (idelta) { error = xfs_mod_icount(mp, idelta); - if (error) - goto out_undo_fdblocks; + ASSERT(!error); }
if (ifreedelta) { error = xfs_mod_ifree(mp, ifreedelta); - if (error) - goto out_undo_icount; + ASSERT(!error); }
if (rtxdelta == 0 && !(tp->t_flags & XFS_TRANS_SB_DIRTY)) @@ -609,95 +558,23 @@ xfs_trans_unreserve_and_mod_sb(
/* apply remaining deltas */ spin_lock(&mp->m_sb_lock); - if (rtxdelta) { - error = xfs_sb_mod64(&mp->m_sb.sb_frextents, rtxdelta); - if (error) - goto out_undo_ifree; - } - - 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; - } + mp->m_sb.sb_frextents += rtxdelta; + mp->m_sb.sb_dblocks += tp->t_dblocks_delta; + mp->m_sb.sb_agcount += tp->t_agcount_delta; + mp->m_sb.sb_imax_pct += tp->t_imaxpct_delta; + mp->m_sb.sb_rextsize += tp->t_rextsize_delta; + mp->m_sb.sb_rbmblocks += tp->t_rbmblocks_delta; + mp->m_sb.sb_rblocks += tp->t_rblocks_delta; + mp->m_sb.sb_rextents += tp->t_rextents_delta; + mp->m_sb.sb_rextslog += tp->t_rextslog_delta; 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_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: - if (idelta) - xfs_mod_icount(mp, -idelta); -out_undo_fdblocks: - if (blkdelta) - xfs_mod_fdblocks(mp, -blkdelta, rsvd); -out: - ASSERT(error == 0); + /* + * Debug checks outside of the spinlock so they don't lock up the + * machine if they fail. + */ + ASSERT(mp->m_sb.sb_imax_pct >= 0); + ASSERT(mp->m_sb.sb_rextslog >= 0); return; }