| Message ID | 157984320125.3139258.966527323692871610.stgit@magnolia (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | xfs: make buffer functions return error codes | expand |
On Thu, Jan 23, 2020 at 09:20:01PM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@oracle.com> > > Refactor xfs_read_agf and xfs_alloc_read_agf to return EAGAIN if the > caller passed TRYLOCK and we weren't able to get the lock; and change > the callers to recognize this. > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> > --- > fs/xfs/libxfs/xfs_alloc.c | 36 ++++++++++++++---------------------- > fs/xfs/libxfs/xfs_bmap.c | 11 ++++++----- > fs/xfs/xfs_filestream.c | 11 +++++------ > 3 files changed, 25 insertions(+), 33 deletions(-) The alloc flag assert changes make the error handling much simpler :) Reviewed-by: Dave Chinner <dchinner@redhat.com>
On Thu, Jan 23, 2020 at 09:20:01PM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@oracle.com> > > Refactor xfs_read_agf and xfs_alloc_read_agf to return EAGAIN if the > caller passed TRYLOCK and we weren't able to get the lock; and change > the callers to recognize this. > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> > --- > fs/xfs/libxfs/xfs_alloc.c | 36 ++++++++++++++---------------------- > fs/xfs/libxfs/xfs_bmap.c | 11 ++++++----- > fs/xfs/xfs_filestream.c | 11 +++++------ > 3 files changed, 25 insertions(+), 33 deletions(-) > > > diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c > index 34b65635ee34..d8053bc96c4d 100644 > --- a/fs/xfs/libxfs/xfs_alloc.c > +++ b/fs/xfs/libxfs/xfs_alloc.c > @@ -2502,12 +2502,11 @@ xfs_alloc_fix_freelist( > > if (!pag->pagf_init) { > error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp); > - if (error) > + if (error) { > + /* Couldn't lock the AGF so skip this AG. */ > + if (error == -EAGAIN) > + error = 0; > goto out_no_agbp; > - if (!pag->pagf_init) { > - ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); > - ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); > - goto out_agbp_relse; > } > } > > @@ -2533,11 +2532,10 @@ xfs_alloc_fix_freelist( > */ > if (!agbp) { > error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp); > - if (error) > - goto out_no_agbp; > - if (!agbp) { > - ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); > - ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); > + if (error) { > + /* Couldn't lock the AGF so skip this AG. */ > + if (error == -EAGAIN) > + error = 0; > goto out_no_agbp; > } > } > @@ -2768,11 +2766,10 @@ xfs_alloc_pagf_init( > xfs_buf_t *bp; > int error; > > - if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp))) > - return error; > - if (bp) > + error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp); > + if (!error) > xfs_trans_brelse(tp, bp); > - return 0; > + return error; > } > > /* > @@ -2961,12 +2958,6 @@ xfs_read_agf( > error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, > XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)), > XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops); > - /* > - * Callers of xfs_read_agf() currently interpret a NULL bpp as EAGAIN > - * and need to be converted to check for EAGAIN specifically. > - */ > - if (error == -EAGAIN) > - return 0; > if (error) > return error; > > @@ -2992,14 +2983,15 @@ xfs_alloc_read_agf( > > trace_xfs_alloc_read_agf(mp, agno); > > + /* We don't support trylock when freeing. */ > + ASSERT((flags & (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)) != > + (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)); Does this assert really work? Shouldn't it be ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING) || !(flags & XFS_ALLOC_FLAG_TRYLOCK)); Otherwise looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
On Fri, Jan 24, 2020 at 03:12:07PM -0800, Christoph Hellwig wrote: > > + /* We don't support trylock when freeing. */ > > + ASSERT((flags & (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)) != > > + (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)); > > Does this assert really work? Shouldn't it be > > ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING) || > !(flags & XFS_ALLOC_FLAG_TRYLOCK)); Actually, I'll take that back - your version is doing the right thing. It just isn't quite as obvious to read.
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 34b65635ee34..d8053bc96c4d 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -2502,12 +2502,11 @@ xfs_alloc_fix_freelist( if (!pag->pagf_init) { error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp); - if (error) + if (error) { + /* Couldn't lock the AGF so skip this AG. */ + if (error == -EAGAIN) + error = 0; goto out_no_agbp; - if (!pag->pagf_init) { - ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); - ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); - goto out_agbp_relse; } } @@ -2533,11 +2532,10 @@ xfs_alloc_fix_freelist( */ if (!agbp) { error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp); - if (error) - goto out_no_agbp; - if (!agbp) { - ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); - ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); + if (error) { + /* Couldn't lock the AGF so skip this AG. */ + if (error == -EAGAIN) + error = 0; goto out_no_agbp; } } @@ -2768,11 +2766,10 @@ xfs_alloc_pagf_init( xfs_buf_t *bp; int error; - if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp))) - return error; - if (bp) + error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp); + if (!error) xfs_trans_brelse(tp, bp); - return 0; + return error; } /* @@ -2961,12 +2958,6 @@ xfs_read_agf( error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)), XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops); - /* - * Callers of xfs_read_agf() currently interpret a NULL bpp as EAGAIN - * and need to be converted to check for EAGAIN specifically. - */ - if (error == -EAGAIN) - return 0; if (error) return error; @@ -2992,14 +2983,15 @@ xfs_alloc_read_agf( trace_xfs_alloc_read_agf(mp, agno); + /* We don't support trylock when freeing. */ + ASSERT((flags & (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)) != + (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)); ASSERT(agno != NULLAGNUMBER); error = xfs_read_agf(mp, tp, agno, (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0, bpp); if (error) return error; - if (!*bpp) - return 0; ASSERT(!(*bpp)->b_error); agf = XFS_BUF_TO_AGF(*bpp); diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index cfcef076c72f..9a6d7a84689a 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -3311,11 +3311,12 @@ xfs_bmap_longest_free_extent( pag = xfs_perag_get(mp, ag); if (!pag->pagf_init) { error = xfs_alloc_pagf_init(mp, tp, ag, XFS_ALLOC_FLAG_TRYLOCK); - if (error) - goto out; - - if (!pag->pagf_init) { - *notinit = 1; + if (error) { + /* Couldn't lock the AGF, so skip this AG. */ + if (error == -EAGAIN) { + *notinit = 1; + error = 0; + } goto out; } } diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c index 5f12b5d8527a..1a88025e68a3 100644 --- a/fs/xfs/xfs_filestream.c +++ b/fs/xfs/xfs_filestream.c @@ -159,16 +159,15 @@ xfs_filestream_pick_ag( if (!pag->pagf_init) { err = xfs_alloc_pagf_init(mp, NULL, ag, trylock); - if (err && !trylock) { + if (err) { xfs_perag_put(pag); - return err; + if (err != -EAGAIN) + return err; + /* Couldn't lock the AGF, skip this AG. */ + continue; } } - /* Might fail sometimes during the 1st pass with trylock set. */ - if (!pag->pagf_init) - goto next_ag; - /* Keep track of the AG with the most free blocks. */ if (pag->pagf_freeblks > maxfree) { maxfree = pag->pagf_freeblks;