On Wed, Dec 09, 2020 at 09:11:45PM +0800, Yafang Shao wrote: > The xfs_trans context should be active after it is allocated, and > deactive when it is freed. > > So these two helpers are refactored as, > - xfs_trans_context_set() > Used in xfs_trans_alloc() > - xfs_trans_context_clear() > Used in xfs_trans_free() > > This patch is based on Darrick's work to fix the issue in xfs/141 in the > earlier version. [1] > > 1. https://lore.kernel.org/linux-xfs/20201104001649.GN7123@magnolia > > Cc: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Dave Chinner <david@xxxxxxxxxxxxx> > Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx> > --- > fs/xfs/xfs_trans.c | 28 +++++++++++++++------------- > 1 file changed, 15 insertions(+), 13 deletions(-) > > diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c > index 11d390f0d3f2..4f4645329bb2 100644 > --- a/fs/xfs/xfs_trans.c > +++ b/fs/xfs/xfs_trans.c > @@ -67,6 +67,17 @@ xfs_trans_free( > xfs_extent_busy_sort(&tp->t_busy); > xfs_extent_busy_clear(tp->t_mountp, &tp->t_busy, false); > > + > + /* Detach the transaction from this thread. */ > + ASSERT(current->journal_info != NULL); > + /* > + * The PF_MEMALLOC_NOFS is bound to the transaction itself instead > + * of the reservation, so we need to check if tp is still the > + * current transaction before clearing the flag. > + */ > + if (current->journal_info == tp) Um, you don't start setting journal_info until the next patch, so this means that someone who lands on this commit with git bisect will have a xfs with broken logic. Because this is the patch that changes where we set and restore NOFS context, I think you have to introduce xfs_trans_context_swap here, and not in the next patch. I also think the _swap routine has to move the old NOFS state to the new transaction's t_pflags, and then set NOFS in the old transaction's t_pflags so that when we clear the context on the old transaction we don't actually change the thread's NOFS state. --D > + xfs_trans_context_clear(tp); > + > trace_xfs_trans_free(tp, _RET_IP_); > if (!(tp->t_flags & XFS_TRANS_NO_WRITECOUNT)) > sb_end_intwrite(tp->t_mountp->m_super); > @@ -153,9 +164,6 @@ xfs_trans_reserve( > int error = 0; > bool rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0; > > - /* Mark this thread as being in a transaction */ > - xfs_trans_context_set(tp); > - > /* > * Attempt to reserve the needed disk blocks by decrementing > * the number needed from the number available. This will > @@ -163,10 +171,9 @@ xfs_trans_reserve( > */ > if (blocks > 0) { > error = xfs_mod_fdblocks(mp, -((int64_t)blocks), rsvd); > - if (error != 0) { > - xfs_trans_context_clear(tp); > + if (error != 0) > return -ENOSPC; > - } > + > tp->t_blk_res += blocks; > } > > @@ -241,8 +248,6 @@ xfs_trans_reserve( > tp->t_blk_res = 0; > } > > - xfs_trans_context_clear(tp); > - > return error; > } > > @@ -284,6 +289,8 @@ xfs_trans_alloc( > INIT_LIST_HEAD(&tp->t_dfops); > tp->t_firstblock = NULLFSBLOCK; > > + /* Mark this thread as being in a transaction */ > + xfs_trans_context_set(tp); > error = xfs_trans_reserve(tp, resp, blocks, rtextents); > if (error) { > xfs_trans_cancel(tp); > @@ -878,7 +885,6 @@ __xfs_trans_commit( > > xfs_log_commit_cil(mp, tp, &commit_lsn, regrant); > > - xfs_trans_context_clear(tp); > xfs_trans_free(tp); > > /* > @@ -911,7 +917,6 @@ __xfs_trans_commit( > tp->t_ticket = NULL; > } > > - xfs_trans_context_clear(tp); > xfs_trans_free_items(tp, !!error); > xfs_trans_free(tp); > > @@ -971,9 +976,6 @@ xfs_trans_cancel( > tp->t_ticket = NULL; > } > > - /* mark this thread as no longer being in a transaction */ > - xfs_trans_context_clear(tp); > - > xfs_trans_free_items(tp, dirty); > xfs_trans_free(tp); > } > -- > 2.18.4 >
