| Message ID | 20241023133755.524345-3-hch@lst.de (mailing list archive) |
|---|---|
| State | Under Review |
| Headers | show |
| Series | [1/2] xfs: fix finding a last resort AG in xfs_filestream_pick_ag | expand |
On Wed, Oct 23, 2024 at 03:37:23PM +0200, Christoph Hellwig wrote: > Directly return the error from xfs_bmap_longest_free_extent instead > of breaking from the loop and handling it there, and use a done > label to directly jump to the exist when we found a suitable perag > structure to reduce the indentation level and pag/max_pag check > complexity in the tail of the function. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Looks fine to me, Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/xfs/xfs_filestream.c | 96 ++++++++++++++++++++--------------------- > 1 file changed, 46 insertions(+), 50 deletions(-) > > diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c > index 88bd23ce74cd..290ba8887d29 100644 > --- a/fs/xfs/xfs_filestream.c > +++ b/fs/xfs/xfs_filestream.c > @@ -67,22 +67,28 @@ xfs_filestream_pick_ag( > xfs_extlen_t minfree, maxfree = 0; > xfs_agnumber_t agno; > bool first_pass = true; > - int err; > > /* 2% of an AG's blocks must be free for it to be chosen. */ > minfree = mp->m_sb.sb_agblocks / 50; > > restart: > for_each_perag_wrap(mp, start_agno, agno, pag) { > + int err; > + > trace_xfs_filestream_scan(pag, pino); > + > *longest = 0; > err = xfs_bmap_longest_free_extent(pag, NULL, longest); > if (err) { > - if (err != -EAGAIN) > - break; > - /* Couldn't lock the AGF, skip this AG. */ > - err = 0; > - continue; > + if (err == -EAGAIN) { > + /* Couldn't lock the AGF, skip this AG. */ > + err = 0; > + continue; > + } > + xfs_perag_rele(pag); > + if (max_pag) > + xfs_perag_rele(max_pag); > + return err; > } > > /* Keep track of the AG with the most free blocks. */ > @@ -107,7 +113,9 @@ xfs_filestream_pick_ag( > !(flags & XFS_PICK_USERDATA) || > (flags & XFS_PICK_LOWSPACE))) { > /* Break out, retaining the reference on the AG. */ > - break; > + if (max_pag) > + xfs_perag_rele(max_pag); > + goto done; > } > } > > @@ -115,56 +123,44 @@ xfs_filestream_pick_ag( > atomic_dec(&pag->pagf_fstrms); > } > > - if (err) { > - xfs_perag_rele(pag); > - if (max_pag) > - xfs_perag_rele(max_pag); > - return err; > + /* > + * Allow a second pass to give xfs_bmap_longest_free_extent() another > + * attempt at locking AGFs that it might have skipped over before we > + * fail. > + */ > + if (first_pass) { > + first_pass = false; > + goto restart; > } > > - if (!pag) { > - /* > - * Allow a second pass to give xfs_bmap_longest_free_extent() > - * another attempt at locking AGFs that it might have skipped > - * over before we fail. > - */ > - if (first_pass) { > - first_pass = false; > - goto restart; > - } > - > - /* > - * We must be low on data space, so run a final lowspace > - * optimised selection pass if we haven't already. > - */ > - if (!(flags & XFS_PICK_LOWSPACE)) { > - flags |= XFS_PICK_LOWSPACE; > - goto restart; > - } > - > - /* > - * No unassociated AGs are available, so select the AG with the > - * most free space, regardless of whether it's already in use by > - * another filestream. It none suit, just use whatever AG we can > - * grab. > - */ > - if (!max_pag) { > - for_each_perag_wrap(args->mp, 0, start_agno, pag) { > - max_pag = pag; > - break; > - } > + /* > + * We must be low on data space, so run a final lowspace optimised > + * selection pass if we haven't already. > + */ > + if (!(flags & XFS_PICK_LOWSPACE)) { > + flags |= XFS_PICK_LOWSPACE; > + goto restart; > + } > > - /* Bail if there are no AGs at all to select from. */ > - if (!max_pag) > - return -ENOSPC; > + /* > + * No unassociated AGs are available, so select the AG with the most > + * free space, regardless of whether it's already in use by another > + * filestream. It none suit, just use whatever AG we can grab. > + */ > + if (!max_pag) { > + for_each_perag_wrap(args->mp, 0, start_agno, pag) { > + max_pag = pag; > + break; > } > > - pag = max_pag; > - atomic_inc(&pag->pagf_fstrms); > - } else if (max_pag) { > - xfs_perag_rele(max_pag); > + /* Bail if there are no AGs at all to select from. */ > + if (!max_pag) > + return -ENOSPC; > } > > + pag = max_pag; > + atomic_inc(&pag->pagf_fstrms); > +done: > trace_xfs_filestream_pick(pag, pino); > args->pag = pag; > return 0; > -- > 2.45.2 > >
diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c index 88bd23ce74cd..290ba8887d29 100644 --- a/fs/xfs/xfs_filestream.c +++ b/fs/xfs/xfs_filestream.c @@ -67,22 +67,28 @@ xfs_filestream_pick_ag( xfs_extlen_t minfree, maxfree = 0; xfs_agnumber_t agno; bool first_pass = true; - int err; /* 2% of an AG's blocks must be free for it to be chosen. */ minfree = mp->m_sb.sb_agblocks / 50; restart: for_each_perag_wrap(mp, start_agno, agno, pag) { + int err; + trace_xfs_filestream_scan(pag, pino); + *longest = 0; err = xfs_bmap_longest_free_extent(pag, NULL, longest); if (err) { - if (err != -EAGAIN) - break; - /* Couldn't lock the AGF, skip this AG. */ - err = 0; - continue; + if (err == -EAGAIN) { + /* Couldn't lock the AGF, skip this AG. */ + err = 0; + continue; + } + xfs_perag_rele(pag); + if (max_pag) + xfs_perag_rele(max_pag); + return err; } /* Keep track of the AG with the most free blocks. */ @@ -107,7 +113,9 @@ xfs_filestream_pick_ag( !(flags & XFS_PICK_USERDATA) || (flags & XFS_PICK_LOWSPACE))) { /* Break out, retaining the reference on the AG. */ - break; + if (max_pag) + xfs_perag_rele(max_pag); + goto done; } } @@ -115,56 +123,44 @@ xfs_filestream_pick_ag( atomic_dec(&pag->pagf_fstrms); } - if (err) { - xfs_perag_rele(pag); - if (max_pag) - xfs_perag_rele(max_pag); - return err; + /* + * Allow a second pass to give xfs_bmap_longest_free_extent() another + * attempt at locking AGFs that it might have skipped over before we + * fail. + */ + if (first_pass) { + first_pass = false; + goto restart; } - if (!pag) { - /* - * Allow a second pass to give xfs_bmap_longest_free_extent() - * another attempt at locking AGFs that it might have skipped - * over before we fail. - */ - if (first_pass) { - first_pass = false; - goto restart; - } - - /* - * We must be low on data space, so run a final lowspace - * optimised selection pass if we haven't already. - */ - if (!(flags & XFS_PICK_LOWSPACE)) { - flags |= XFS_PICK_LOWSPACE; - goto restart; - } - - /* - * No unassociated AGs are available, so select the AG with the - * most free space, regardless of whether it's already in use by - * another filestream. It none suit, just use whatever AG we can - * grab. - */ - if (!max_pag) { - for_each_perag_wrap(args->mp, 0, start_agno, pag) { - max_pag = pag; - break; - } + /* + * We must be low on data space, so run a final lowspace optimised + * selection pass if we haven't already. + */ + if (!(flags & XFS_PICK_LOWSPACE)) { + flags |= XFS_PICK_LOWSPACE; + goto restart; + } - /* Bail if there are no AGs at all to select from. */ - if (!max_pag) - return -ENOSPC; + /* + * No unassociated AGs are available, so select the AG with the most + * free space, regardless of whether it's already in use by another + * filestream. It none suit, just use whatever AG we can grab. + */ + if (!max_pag) { + for_each_perag_wrap(args->mp, 0, start_agno, pag) { + max_pag = pag; + break; } - pag = max_pag; - atomic_inc(&pag->pagf_fstrms); - } else if (max_pag) { - xfs_perag_rele(max_pag); + /* Bail if there are no AGs at all to select from. */ + if (!max_pag) + return -ENOSPC; } + pag = max_pag; + atomic_inc(&pag->pagf_fstrms); +done: trace_xfs_filestream_pick(pag, pino); args->pag = pag; return 0;
Directly return the error from xfs_bmap_longest_free_extent instead of breaking from the loop and handling it there, and use a done label to directly jump to the exist when we found a suitable perag structure to reduce the indentation level and pag/max_pag check complexity in the tail of the function. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/xfs/xfs_filestream.c | 96 ++++++++++++++++++++--------------------- 1 file changed, 46 insertions(+), 50 deletions(-)