Re: [PATCH 08/12] xfs: use GFP_KERNEL in pure transaction contexts

Darrick J. Wong
2024-01-18T23:38:22Z

On Tue, Jan 16, 2024 at 09:59:46AM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> When running in a transaction context, memory allocations are scoped
> to GFP_NOFS. Hence we don't need to use GFP_NOFS contexts in pure
> transaction context allocations - GFP_KERNEL will automatically get
> converted to GFP_NOFS as appropriate.
>
> Go through the code and convert all the obvious GFP_NOFS allocations
> in transaction context to use GFP_KERNEL. This further reduces the
> explicit use of GFP_NOFS in XFS.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> fs/xfs/libxfs/xfs_attr.c | 3 ++-
> fs/xfs/libxfs/xfs_bmap.c | 2 +-
> fs/xfs/libxfs/xfs_defer.c | 6 +++---
> fs/xfs/libxfs/xfs_dir2.c | 8 ++++----
> fs/xfs/libxfs/xfs_inode_fork.c | 8 ++++----
> fs/xfs/libxfs/xfs_refcount.c | 2 +-
> fs/xfs/libxfs/xfs_rmap.c | 2 +-
> fs/xfs/xfs_attr_item.c | 4 ++--
> fs/xfs/xfs_bmap_util.c | 2 +-
> fs/xfs/xfs_buf.c | 28 +++++++++++++++++-----------
> fs/xfs/xfs_log.c | 3 ++-
> fs/xfs/xfs_mru_cache.c | 2 +-
> 12 files changed, 39 insertions(+), 31 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> index 9976a00a73f9..269a57420859 100644
> --- a/fs/xfs/libxfs/xfs_attr.c
> +++ b/fs/xfs/libxfs/xfs_attr.c
> @@ -891,7 +891,8 @@ xfs_attr_defer_add(
>
> struct xfs_attr_intent *new;
>
> - new = kmem_cache_zalloc(xfs_attr_intent_cache, GFP_NOFS | __GFP_NOFAIL);
> + new = kmem_cache_zalloc(xfs_attr_intent_cache,
> + GFP_KERNEL | __GFP_NOFAIL);
> new->xattri_op_flags = op_flags;
> new->xattri_da_args = args;
>
> diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> index 98aaca933bdd..fbdaa53deecd 100644
> --- a/fs/xfs/libxfs/xfs_bmap.c
> +++ b/fs/xfs/libxfs/xfs_bmap.c
> @@ -6098,7 +6098,7 @@ __xfs_bmap_add(
> bmap->br_blockcount,
> bmap->br_state);
>
> - bi = kmem_cache_alloc(xfs_bmap_intent_cache, GFP_NOFS | __GFP_NOFAIL);
> + bi = kmem_cache_alloc(xfs_bmap_intent_cache, GFP_KERNEL | __GFP_NOFAIL);
> INIT_LIST_HEAD(&bi->bi_list);
> bi->bi_type = type;
> bi->bi_owner = ip;
> diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c
> index 75689c151a54..8ae4401f6810 100644
> --- a/fs/xfs/libxfs/xfs_defer.c
> +++ b/fs/xfs/libxfs/xfs_defer.c
> @@ -825,7 +825,7 @@ xfs_defer_alloc(
> struct xfs_defer_pending *dfp;
>
> dfp = kmem_cache_zalloc(xfs_defer_pending_cache,
> - GFP_NOFS | __GFP_NOFAIL);
> + GFP_KERNEL | __GFP_NOFAIL);
> dfp->dfp_ops = ops;
> INIT_LIST_HEAD(&dfp->dfp_work);
> list_add_tail(&dfp->dfp_list, &tp->t_dfops);
> @@ -888,7 +888,7 @@ xfs_defer_start_recovery(
> struct xfs_defer_pending *dfp;
>
> dfp = kmem_cache_zalloc(xfs_defer_pending_cache,
> - GFP_NOFS | __GFP_NOFAIL);
> + GFP_KERNEL | __GFP_NOFAIL);
> dfp->dfp_ops = ops;
> dfp->dfp_intent = lip;
> INIT_LIST_HEAD(&dfp->dfp_work);
> @@ -979,7 +979,7 @@ xfs_defer_ops_capture(
> return ERR_PTR(error);
>
> /* Create an object to capture the defer ops. */
> - dfc = kzalloc(sizeof(*dfc), GFP_NOFS | __GFP_NOFAIL);
> + dfc = kzalloc(sizeof(*dfc), GFP_KERNEL | __GFP_NOFAIL);
> INIT_LIST_HEAD(&dfc->dfc_list);
> INIT_LIST_HEAD(&dfc->dfc_dfops);
>
> diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c
> index 728f72f0d078..8c9403b33191 100644
> --- a/fs/xfs/libxfs/xfs_dir2.c
> +++ b/fs/xfs/libxfs/xfs_dir2.c
> @@ -236,7 +236,7 @@ xfs_dir_init(
> if (error)
> return error;
>
> - args = kzalloc(sizeof(*args), GFP_NOFS | __GFP_NOFAIL);
> + args = kzalloc(sizeof(*args), GFP_KERNEL | __GFP_NOFAIL);
> if (!args)
> return -ENOMEM;
>
> @@ -273,7 +273,7 @@ xfs_dir_createname(
> XFS_STATS_INC(dp->i_mount, xs_dir_create);
> }
>
> - args = kzalloc(sizeof(*args), GFP_NOFS | __GFP_NOFAIL);
> + args = kzalloc(sizeof(*args), GFP_KERNEL | __GFP_NOFAIL);
> if (!args)
> return -ENOMEM;
>
> @@ -435,7 +435,7 @@ xfs_dir_removename(
> ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
> XFS_STATS_INC(dp->i_mount, xs_dir_remove);
>
> - args = kzalloc(sizeof(*args), GFP_NOFS | __GFP_NOFAIL);
> + args = kzalloc(sizeof(*args), GFP_KERNEL | __GFP_NOFAIL);
> if (!args)
> return -ENOMEM;
>
> @@ -496,7 +496,7 @@ xfs_dir_replace(
> if (rval)
> return rval;
>
> - args = kzalloc(sizeof(*args), GFP_NOFS | __GFP_NOFAIL);
> + args = kzalloc(sizeof(*args), GFP_KERNEL | __GFP_NOFAIL);
> if (!args)
> return -ENOMEM;
>
> diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
> index 709fda3d742f..136d5d7b9de9 100644
> --- a/fs/xfs/libxfs/xfs_inode_fork.c
> +++ b/fs/xfs/libxfs/xfs_inode_fork.c
> @@ -402,7 +402,7 @@ xfs_iroot_realloc(
> if (ifp->if_broot_bytes == 0) {
> new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, rec_diff);
> ifp->if_broot = kmalloc(new_size,
> - GFP_NOFS | __GFP_NOFAIL);
> + GFP_KERNEL | __GFP_NOFAIL);
> ifp->if_broot_bytes = (int)new_size;
> return;
> }
> @@ -417,7 +417,7 @@ xfs_iroot_realloc(
> new_max = cur_max + rec_diff;
> new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
> ifp->if_broot = krealloc(ifp->if_broot, new_size,
> - GFP_NOFS | __GFP_NOFAIL);
> + GFP_KERNEL | __GFP_NOFAIL);
> op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
> ifp->if_broot_bytes);
> np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
> @@ -443,7 +443,7 @@ xfs_iroot_realloc(
> else
> new_size = 0;
> if (new_size > 0) {
> - new_broot = kmalloc(new_size, GFP_NOFS | __GFP_NOFAIL);
> + new_broot = kmalloc(new_size, GFP_KERNEL | __GFP_NOFAIL);
> /*
> * First copy over the btree block header.
> */
> @@ -512,7 +512,7 @@ xfs_idata_realloc(
>
> if (byte_diff) {
> ifp->if_data = krealloc(ifp->if_data, new_size,
> - GFP_NOFS | __GFP_NOFAIL);
> + GFP_KERNEL | __GFP_NOFAIL);
> if (new_size == 0)
> ifp->if_data = NULL;
> ifp->if_bytes = new_size;
> diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c
> index 6709a7f8bad5..7df52daa22cf 100644
> --- a/fs/xfs/libxfs/xfs_refcount.c
> +++ b/fs/xfs/libxfs/xfs_refcount.c
> @@ -1449,7 +1449,7 @@ __xfs_refcount_add(
> blockcount);
>
> ri = kmem_cache_alloc(xfs_refcount_intent_cache,
> - GFP_NOFS | __GFP_NOFAIL);
> + GFP_KERNEL | __GFP_NOFAIL);
> INIT_LIST_HEAD(&ri->ri_list);
> ri->ri_type = type;
> ri->ri_startblock = startblock;
> diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c
> index 76bf7f48cb5a..0bd1f47b2c2b 100644
> --- a/fs/xfs/libxfs/xfs_rmap.c
> +++ b/fs/xfs/libxfs/xfs_rmap.c
> @@ -2559,7 +2559,7 @@ __xfs_rmap_add(
> bmap->br_blockcount,
> bmap->br_state);
>
> - ri = kmem_cache_alloc(xfs_rmap_intent_cache, GFP_NOFS | __GFP_NOFAIL);
> + ri = kmem_cache_alloc(xfs_rmap_intent_cache, GFP_KERNEL | __GFP_NOFAIL);
> INIT_LIST_HEAD(&ri->ri_list);
> ri->ri_type = type;
> ri->ri_owner = owner;
> diff --git a/fs/xfs/xfs_attr_item.c b/fs/xfs/xfs_attr_item.c
> index 2a142cefdc3d..0bf25a2ba3b6 100644
> --- a/fs/xfs/xfs_attr_item.c
> +++ b/fs/xfs/xfs_attr_item.c
> @@ -226,7 +226,7 @@ xfs_attri_init(
> {
> struct xfs_attri_log_item *attrip;
>
> - attrip = kmem_cache_zalloc(xfs_attri_cache, GFP_NOFS | __GFP_NOFAIL);
> + attrip = kmem_cache_zalloc(xfs_attri_cache, GFP_KERNEL | __GFP_NOFAIL);
>
> /*
> * Grab an extra reference to the name/value buffer for this log item.
> @@ -666,7 +666,7 @@ xfs_attr_create_done(
>
> attrip = ATTRI_ITEM(intent);
>
> - attrdp = kmem_cache_zalloc(xfs_attrd_cache, GFP_NOFS | __GFP_NOFAIL);
> + attrdp = kmem_cache_zalloc(xfs_attrd_cache, GFP_KERNEL | __GFP_NOFAIL);
>
> xfs_log_item_init(tp->t_mountp, &attrdp->attrd_item, XFS_LI_ATTRD,
> &xfs_attrd_item_ops);
> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
> index c2531c28905c..cb2a4b940292 100644
> --- a/fs/xfs/xfs_bmap_util.c
> +++ b/fs/xfs/xfs_bmap_util.c
> @@ -66,7 +66,7 @@ xfs_zero_extent(
> return blkdev_issue_zeroout(target->bt_bdev,
> block << (mp->m_super->s_blocksize_bits - 9),
> count_fsb << (mp->m_super->s_blocksize_bits - 9),
> - GFP_NOFS, 0);
> + GFP_KERNEL, 0);
> }
>
> /*
> diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
> index a09ffbbb0dda..de99368000b4 100644
> --- a/fs/xfs/xfs_buf.c
> +++ b/fs/xfs/xfs_buf.c
> @@ -190,7 +190,7 @@ xfs_buf_get_maps(
> }
>
> bp->b_maps = kzalloc(map_count * sizeof(struct xfs_buf_map),
> - GFP_NOFS | __GFP_NOFAIL);
> + GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL);
> if (!bp->b_maps)
> return -ENOMEM;
> return 0;
> @@ -222,7 +222,8 @@ _xfs_buf_alloc(
> int i;
>
> *bpp = NULL;
> - bp = kmem_cache_zalloc(xfs_buf_cache, GFP_NOFS | __GFP_NOFAIL);
> + bp = kmem_cache_zalloc(xfs_buf_cache,
> + GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL);
>
> /*
> * We don't want certain flags to appear in b_flags unless they are
> @@ -325,7 +326,7 @@ xfs_buf_alloc_kmem(
> struct xfs_buf *bp,
> xfs_buf_flags_t flags)
> {
> - gfp_t gfp_mask = GFP_NOFS | __GFP_NOFAIL;
> + gfp_t gfp_mask = GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL;
> size_t size = BBTOB(bp->b_length);
>
> /* Assure zeroed buffer for non-read cases. */
> @@ -356,13 +357,11 @@ xfs_buf_alloc_pages(
> struct xfs_buf *bp,
> xfs_buf_flags_t flags)
> {
> - gfp_t gfp_mask = __GFP_NOWARN;
> + gfp_t gfp_mask = GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOWARN;
> long filled = 0;
>
> if (flags & XBF_READ_AHEAD)
> gfp_mask |= __GFP_NORETRY;
> - else
> - gfp_mask |= GFP_NOFS;
>
> /* Make sure that we have a page list */
> bp->b_page_count = DIV_ROUND_UP(BBTOB(bp->b_length), PAGE_SIZE);
> @@ -429,11 +428,18 @@ _xfs_buf_map_pages(
>
> /*
> * vm_map_ram() will allocate auxiliary structures (e.g.
> - * pagetables) with GFP_KERNEL, yet we are likely to be under
> - * GFP_NOFS context here. Hence we need to tell memory reclaim
> - * that we are in such a context via PF_MEMALLOC_NOFS to prevent
> - * memory reclaim re-entering the filesystem here and
> - * potentially deadlocking.
> + * pagetables) with GFP_KERNEL, yet we often under a scoped nofs
> + * context here. Mixing GFP_KERNEL with GFP_NOFS allocations
> + * from the same call site that can be run from both above and
> + * below memory reclaim causes lockdep false positives. Hence we
> + * always need to force this allocation to nofs context because
> + * we can't pass __GFP_NOLOCKDEP down to auxillary structures to
> + * prevent false positive lockdep reports.
> + *
> + * XXX(dgc): I think dquot reclaim is the only place we can get
> + * to this function from memory reclaim context now. If we fix
> + * that like we've fixed inode reclaim to avoid writeback from
> + * reclaim, this nofs wrapping can go away.
> */
> nofs_flag = memalloc_nofs_save();
> do {
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index ee39639bb92b..1f68569e62ca 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -3518,7 +3518,8 @@ xlog_ticket_alloc(
> struct xlog_ticket *tic;
> int unit_res;
>
> - tic = kmem_cache_zalloc(xfs_log_ticket_cache, GFP_NOFS | __GFP_NOFAIL);
> + tic = kmem_cache_zalloc(xfs_log_ticket_cache,
> + GFP_KERNEL | __GFP_NOFAIL);
>
> unit_res = xlog_calc_unit_res(log, unit_bytes, &tic->t_iclog_hdrs);
>
> diff --git a/fs/xfs/xfs_mru_cache.c b/fs/xfs/xfs_mru_cache.c
> index ce496704748d..7443debaffd6 100644
> --- a/fs/xfs/xfs_mru_cache.c
> +++ b/fs/xfs/xfs_mru_cache.c
> @@ -428,7 +428,7 @@ xfs_mru_cache_insert(
> if (!mru || !mru->lists)
> return -EINVAL;
>
> - if (radix_tree_preload(GFP_NOFS))
> + if (radix_tree_preload(GFP_KERNEL))
> return -ENOMEM;
>
> INIT_LIST_HEAD(&elem->list_node);
> --
> 2.43.0
>
>