Re: [PATCH 5/6] treewide: use kv[mz]alloc* rather than opencoded variants

From: Michal Hocko
Date: Thu Jan 12 2017 - 12:19:40 EST


On Thu 12-01-17 17:54:34, Ilya Dryomov wrote:
> On Thu, Jan 12, 2017 at 4:37 PM, Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> > From: Michal Hocko <mhocko@xxxxxxxx>
> >
> > There are many code paths opencoding kvmalloc. Let's use the helper
> > instead. The main difference to kvmalloc is that those users are usually
> > not considering all the aspects of the memory allocator. E.g. allocation
> > requests < 64kB are basically never failing and invoke OOM killer to
> > satisfy the allocation. This sounds too disruptive for something that
> > has a reasonable fallback - the vmalloc. On the other hand those
> > requests might fallback to vmalloc even when the memory allocator would
> > succeed after several more reclaim/compaction attempts previously. There
> > is no guarantee something like that happens though.
> >
> > This patch converts many of those places to kv[mz]alloc* helpers because
> > they are more conservative.
> >
> > Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
> > Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
> > Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> > Cc: Anton Vorontsov <anton@xxxxxxxxxx>
> > Cc: Colin Cross <ccross@xxxxxxxxxxx>
> > Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> > Cc: Tony Luck <tony.luck@xxxxxxxxx>
> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> > Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
> > Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
> > Cc: Santosh Raspatur <santosh@xxxxxxxxxxx>
> > Cc: Hariprasad S <hariprasad@xxxxxxxxxxx>
> > Cc: Tariq Toukan <tariqt@xxxxxxxxxxxx>
> > Cc: Yishai Hadas <yishaih@xxxxxxxxxxxx>
> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> > Cc: Oleg Drokin <oleg.drokin@xxxxxxxxx>
> > Cc: Andreas Dilger <andreas.dilger@xxxxxxxxx>
> > Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> > Cc: David Sterba <dsterba@xxxxxxxx>
> > Cc: "Yan, Zheng" <zyan@xxxxxxxxxx>
> > Cc: Ilya Dryomov <idryomov@xxxxxxxxx>
> > Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
> > Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> > Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
> > Cc: netdev@xxxxxxxxxxxxxxx
> > Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
> > ---
> > arch/s390/kvm/kvm-s390.c | 10 ++-----
> > crypto/lzo.c | 4 +--
> > drivers/acpi/apei/erst.c | 8 ++---
> > drivers/char/agp/generic.c | 8 +----
> > drivers/gpu/drm/nouveau/nouveau_gem.c | 4 +--
> > drivers/md/bcache/util.h | 12 ++------
> > drivers/net/ethernet/chelsio/cxgb3/cxgb3_defs.h | 3 --
> > drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c | 25 ++--------------
> > drivers/net/ethernet/chelsio/cxgb3/l2t.c | 2 +-
> > drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 31 ++++----------------
> > drivers/net/ethernet/mellanox/mlx4/en_tx.c | 9 ++----
> > drivers/net/ethernet/mellanox/mlx4/mr.c | 9 ++----
> > drivers/nvdimm/dimm_devs.c | 5 +---
> > .../staging/lustre/lnet/libcfs/linux/linux-mem.c | 11 +------
> > drivers/xen/evtchn.c | 14 +--------
> > fs/btrfs/ctree.c | 9 ++----
> > fs/btrfs/ioctl.c | 9 ++----
> > fs/btrfs/send.c | 27 ++++++-----------
> > fs/ceph/file.c | 9 ++----
> > fs/select.c | 5 +---
> > fs/xattr.c | 27 ++++++-----------
> > kernel/bpf/hashtab.c | 11 ++-----
> > lib/iov_iter.c | 5 +---
> > mm/frame_vector.c | 5 +---
> > net/ipv4/inet_hashtables.c | 6 +---
> > net/ipv4/tcp_metrics.c | 5 +---
> > net/mpls/af_mpls.c | 5 +---
> > net/netfilter/x_tables.c | 34 ++++++----------------
> > net/netfilter/xt_recent.c | 5 +---
> > net/sched/sch_choke.c | 5 +---
> > net/sched/sch_fq_codel.c | 26 ++++-------------
> > net/sched/sch_hhf.c | 33 ++++++---------------
> > net/sched/sch_netem.c | 6 +---
> > net/sched/sch_sfq.c | 6 +---
> > security/keys/keyctl.c | 22 ++++----------
> > 35 files changed, 96 insertions(+), 319 deletions(-)
> >
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index 4f74511015b8..e6bbb33d2956 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -1126,10 +1126,7 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
> > if (args->count < 1 || args->count > KVM_S390_SKEYS_MAX)
> > return -EINVAL;
> >
> > - keys = kmalloc_array(args->count, sizeof(uint8_t),
> > - GFP_KERNEL | __GFP_NOWARN);
> > - if (!keys)
> > - keys = vmalloc(sizeof(uint8_t) * args->count);
> > + keys = kvmalloc(args->count * sizeof(uint8_t), GFP_KERNEL);
> > if (!keys)
> > return -ENOMEM;
> >
> > @@ -1171,10 +1168,7 @@ static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
> > if (args->count < 1 || args->count > KVM_S390_SKEYS_MAX)
> > return -EINVAL;
> >
> > - keys = kmalloc_array(args->count, sizeof(uint8_t),
> > - GFP_KERNEL | __GFP_NOWARN);
> > - if (!keys)
> > - keys = vmalloc(sizeof(uint8_t) * args->count);
> > + keys = kvmalloc(sizeof(uint8_t) * args->count, GFP_KERNEL);
> > if (!keys)
> > return -ENOMEM;
> >
> > diff --git a/crypto/lzo.c b/crypto/lzo.c
> > index 168df784da84..218567d717d6 100644
> > --- a/crypto/lzo.c
> > +++ b/crypto/lzo.c
> > @@ -32,9 +32,7 @@ static void *lzo_alloc_ctx(struct crypto_scomp *tfm)
> > {
> > void *ctx;
> >
> > - ctx = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL | __GFP_NOWARN);
> > - if (!ctx)
> > - ctx = vmalloc(LZO1X_MEM_COMPRESS);
> > + ctx = kvmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
> > if (!ctx)
> > return ERR_PTR(-ENOMEM);
> >
> > diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
> > index ec4f507b524f..a2898df61744 100644
> > --- a/drivers/acpi/apei/erst.c
> > +++ b/drivers/acpi/apei/erst.c
> > @@ -513,7 +513,7 @@ static int __erst_record_id_cache_add_one(void)
> > if (i < erst_record_id_cache.len)
> > goto retry;
> > if (erst_record_id_cache.len >= erst_record_id_cache.size) {
> > - int new_size, alloc_size;
> > + int new_size;
> > u64 *new_entries;
> >
> > new_size = erst_record_id_cache.size * 2;
> > @@ -524,11 +524,7 @@ static int __erst_record_id_cache_add_one(void)
> > pr_warn(FW_WARN "too many record IDs!\n");
> > return 0;
> > }
> > - alloc_size = new_size * sizeof(entries[0]);
> > - if (alloc_size < PAGE_SIZE)
> > - new_entries = kmalloc(alloc_size, GFP_KERNEL);
> > - else
> > - new_entries = vmalloc(alloc_size);
> > + new_entries = kvmalloc(new_size * sizeof(entries[0]), GFP_KERNEL);
> > if (!new_entries)
> > return -ENOMEM;
> > memcpy(new_entries, entries,
> > diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
> > index f002fa5d1887..bdf418cac8ef 100644
> > --- a/drivers/char/agp/generic.c
> > +++ b/drivers/char/agp/generic.c
> > @@ -88,13 +88,7 @@ static int agp_get_key(void)
> >
> > void agp_alloc_page_array(size_t size, struct agp_memory *mem)
> > {
> > - mem->pages = NULL;
> > -
> > - if (size <= 2*PAGE_SIZE)
> > - mem->pages = kmalloc(size, GFP_KERNEL | __GFP_NOWARN);
> > - if (mem->pages == NULL) {
> > - mem->pages = vmalloc(size);
> > - }
> > + mem->pages = kvmalloc(size, GFP_KERNEL);
> > }
> > EXPORT_SYMBOL(agp_alloc_page_array);
> >
> > diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
> > index 201b52b750dd..77dd73ff126f 100644
> > --- a/drivers/gpu/drm/nouveau/nouveau_gem.c
> > +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
> > @@ -568,9 +568,7 @@ u_memcpya(uint64_t user, unsigned nmemb, unsigned size)
> >
> > size *= nmemb;
> >
> > - mem = kmalloc(size, GFP_KERNEL | __GFP_NOWARN);
> > - if (!mem)
> > - mem = vmalloc(size);
> > + mem = kvmalloc(size, GFP_KERNEL);
> > if (!mem)
> > return ERR_PTR(-ENOMEM);
> >
> > diff --git a/drivers/md/bcache/util.h b/drivers/md/bcache/util.h
> > index cf2cbc211d83..d00bcb64d3a8 100644
> > --- a/drivers/md/bcache/util.h
> > +++ b/drivers/md/bcache/util.h
> > @@ -43,11 +43,7 @@ struct closure;
> > (heap)->used = 0; \
> > (heap)->size = (_size); \
> > _bytes = (heap)->size * sizeof(*(heap)->data); \
> > - (heap)->data = NULL; \
> > - if (_bytes < KMALLOC_MAX_SIZE) \
> > - (heap)->data = kmalloc(_bytes, (gfp)); \
> > - if ((!(heap)->data) && ((gfp) & GFP_KERNEL)) \
> > - (heap)->data = vmalloc(_bytes); \
> > + (heap)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL); \
> > (heap)->data; \
> > })
> >
> > @@ -136,12 +132,8 @@ do { \
> > \
> > (fifo)->mask = _allocated_size - 1; \
> > (fifo)->front = (fifo)->back = 0; \
> > - (fifo)->data = NULL; \
> > \
> > - if (_bytes < KMALLOC_MAX_SIZE) \
> > - (fifo)->data = kmalloc(_bytes, (gfp)); \
> > - if ((!(fifo)->data) && ((gfp) & GFP_KERNEL)) \
> > - (fifo)->data = vmalloc(_bytes); \
> > + (fifo)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL); \
> > (fifo)->data; \
> > })
> >
> > diff --git a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_defs.h b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_defs.h
> > index 920d918ed193..f04e81f33795 100644
> > --- a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_defs.h
> > +++ b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_defs.h
> > @@ -41,9 +41,6 @@
> >
> > #define VALIDATE_TID 1
> >
> > -void *cxgb_alloc_mem(unsigned long size);
> > -void cxgb_free_mem(void *addr);
> > -
> > /*
> > * Map an ATID or STID to their entries in the corresponding TID tables.
> > */
> > diff --git a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
> > index 76684dcb874c..606d4a3ade04 100644
> > --- a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
> > +++ b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
> > @@ -1152,27 +1152,6 @@ static void cxgb_redirect(struct dst_entry *old, struct dst_entry *new,
> > }
> >
> > /*
> > - * Allocate a chunk of memory using kmalloc or, if that fails, vmalloc.
> > - * The allocated memory is cleared.
> > - */
> > -void *cxgb_alloc_mem(unsigned long size)
> > -{
> > - void *p = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
> > -
> > - if (!p)
> > - p = vzalloc(size);
> > - return p;
> > -}
> > -
> > -/*
> > - * Free memory allocated through t3_alloc_mem().
> > - */
> > -void cxgb_free_mem(void *addr)
> > -{
> > - kvfree(addr);
> > -}
> > -
> > -/*
> > * Allocate and initialize the TID tables. Returns 0 on success.
> > */
> > static int init_tid_tabs(struct tid_info *t, unsigned int ntids,
> > @@ -1182,7 +1161,7 @@ static int init_tid_tabs(struct tid_info *t, unsigned int ntids,
> > unsigned long size = ntids * sizeof(*t->tid_tab) +
> > natids * sizeof(*t->atid_tab) + nstids * sizeof(*t->stid_tab);
> >
> > - t->tid_tab = cxgb_alloc_mem(size);
> > + t->tid_tab = kvmalloc(size, GFP_KERNEL);
> > if (!t->tid_tab)
> > return -ENOMEM;
> >
> > @@ -1218,7 +1197,7 @@ static int init_tid_tabs(struct tid_info *t, unsigned int ntids,
> >
> > static void free_tid_maps(struct tid_info *t)
> > {
> > - cxgb_free_mem(t->tid_tab);
> > + kvfree(t->tid_tab);
> > }
> >
> > static inline void add_adapter(struct adapter *adap)
> > diff --git a/drivers/net/ethernet/chelsio/cxgb3/l2t.c b/drivers/net/ethernet/chelsio/cxgb3/l2t.c
> > index 5f226eda8cd6..c9b06501ee0c 100644
> > --- a/drivers/net/ethernet/chelsio/cxgb3/l2t.c
> > +++ b/drivers/net/ethernet/chelsio/cxgb3/l2t.c
> > @@ -444,7 +444,7 @@ struct l2t_data *t3_init_l2t(unsigned int l2t_capacity)
> > struct l2t_data *d;
> > int i, size = sizeof(*d) + l2t_capacity * sizeof(struct l2t_entry);
> >
> > - d = cxgb_alloc_mem(size);
> > + d = kvmalloc(size, GFP_KERNEL);
> > if (!d)
> > return NULL;
> >
> > diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> > index 6f951877430b..671695cb3c15 100644
> > --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> > +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> > @@ -881,27 +881,6 @@ static int setup_sge_queues(struct adapter *adap)
> > return err;
> > }
> >
> > -/*
> > - * Allocate a chunk of memory using kmalloc or, if that fails, vmalloc.
> > - * The allocated memory is cleared.
> > - */
> > -void *t4_alloc_mem(size_t size)
> > -{
> > - void *p = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
> > -
> > - if (!p)
> > - p = vzalloc(size);
> > - return p;
> > -}
> > -
> > -/*
> > - * Free memory allocated through alloc_mem().
> > - */
> > -void t4_free_mem(void *addr)
> > -{
> > - kvfree(addr);
> > -}
> > -
> > static u16 cxgb_select_queue(struct net_device *dev, struct sk_buff *skb,
> > void *accel_priv, select_queue_fallback_t fallback)
> > {
> > @@ -1300,7 +1279,7 @@ static int tid_init(struct tid_info *t)
> > max_ftids * sizeof(*t->ftid_tab) +
> > ftid_bmap_size * sizeof(long);
> >
> > - t->tid_tab = t4_alloc_mem(size);
> > + t->tid_tab = kvmalloc(size, GFP_KERNEL);
> > if (!t->tid_tab)
> > return -ENOMEM;
> >
> > @@ -3416,7 +3395,7 @@ static int adap_init0(struct adapter *adap)
> > /* allocate memory to read the header of the firmware on the
> > * card
> > */
> > - card_fw = t4_alloc_mem(sizeof(*card_fw));
> > + card_fw = kvmalloc(sizeof(*card_fw), GFP_KERNEL);
> >
> > /* Get FW from from /lib/firmware/ */
> > ret = request_firmware(&fw, fw_info->fw_mod_name,
> > @@ -3436,7 +3415,7 @@ static int adap_init0(struct adapter *adap)
> >
> > /* Cleaning up */
> > release_firmware(fw);
> > - t4_free_mem(card_fw);
> > + kvfree(card_fw);
> >
> > if (ret < 0)
> > goto bye;
> > @@ -4432,9 +4411,9 @@ static void free_some_resources(struct adapter *adapter)
> > {
> > unsigned int i;
> >
> > - t4_free_mem(adapter->l2t);
> > + kvfree(adapter->l2t);
> > t4_cleanup_sched(adapter);
> > - t4_free_mem(adapter->tids.tid_tab);
> > + kvfree(adapter->tids.tid_tab);
> > cxgb4_cleanup_tc_u32(adapter);
> > kfree(adapter->sge.egr_map);
> > kfree(adapter->sge.ingr_map);
> > diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
> > index 5886ad78058f..a5c1b815145e 100644
> > --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
> > +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
> > @@ -70,13 +70,10 @@ int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
> > ring->full_size = ring->size - HEADROOM - MAX_DESC_TXBBS;
> >
> > tmp = size * sizeof(struct mlx4_en_tx_info);
> > - ring->tx_info = kmalloc_node(tmp, GFP_KERNEL | __GFP_NOWARN, node);
> > + ring->tx_info = kvmalloc_node(tmp, GFP_KERNEL, node);
> > if (!ring->tx_info) {
> > - ring->tx_info = vmalloc(tmp);
> > - if (!ring->tx_info) {
> > - err = -ENOMEM;
> > - goto err_ring;
> > - }
> > + err = -ENOMEM;
> > + goto err_ring;
> > }
> >
> > en_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
> > diff --git a/drivers/net/ethernet/mellanox/mlx4/mr.c b/drivers/net/ethernet/mellanox/mlx4/mr.c
> > index 395b5463cfd9..82354fd0a87e 100644
> > --- a/drivers/net/ethernet/mellanox/mlx4/mr.c
> > +++ b/drivers/net/ethernet/mellanox/mlx4/mr.c
> > @@ -115,12 +115,9 @@ static int mlx4_buddy_init(struct mlx4_buddy *buddy, int max_order)
> >
> > for (i = 0; i <= buddy->max_order; ++i) {
> > s = BITS_TO_LONGS(1 << (buddy->max_order - i));
> > - buddy->bits[i] = kcalloc(s, sizeof (long), GFP_KERNEL | __GFP_NOWARN);
> > - if (!buddy->bits[i]) {
> > - buddy->bits[i] = vzalloc(s * sizeof(long));
> > - if (!buddy->bits[i])
> > - goto err_out_free;
> > - }
> > + buddy->bits[i] = kvzalloc(s * sizeof(long), GFP_KERNEL);
> > + if (!buddy->bits[i])
> > + goto err_out_free;
> > }
> >
> > set_bit(0, buddy->bits[buddy->max_order]);
> > diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
> > index 0eedc49e0d47..3bd332b167d9 100644
> > --- a/drivers/nvdimm/dimm_devs.c
> > +++ b/drivers/nvdimm/dimm_devs.c
> > @@ -102,10 +102,7 @@ int nvdimm_init_config_data(struct nvdimm_drvdata *ndd)
> > return -ENXIO;
> > }
> >
> > - ndd->data = kmalloc(ndd->nsarea.config_size, GFP_KERNEL);
> > - if (!ndd->data)
> > - ndd->data = vmalloc(ndd->nsarea.config_size);
> > -
> > + ndd->data = kvmalloc(ndd->nsarea.config_size, GFP_KERNEL);
> > if (!ndd->data)
> > return -ENOMEM;
> >
> > diff --git a/drivers/staging/lustre/lnet/libcfs/linux/linux-mem.c b/drivers/staging/lustre/lnet/libcfs/linux/linux-mem.c
> > index a6a76a681ea9..8f638267e704 100644
> > --- a/drivers/staging/lustre/lnet/libcfs/linux/linux-mem.c
> > +++ b/drivers/staging/lustre/lnet/libcfs/linux/linux-mem.c
> > @@ -45,15 +45,6 @@ EXPORT_SYMBOL(libcfs_kvzalloc);
> > void *libcfs_kvzalloc_cpt(struct cfs_cpt_table *cptab, int cpt, size_t size,
> > gfp_t flags)
> > {
> > - void *ret;
> > -
> > - ret = kzalloc_node(size, flags | __GFP_NOWARN,
> > - cfs_cpt_spread_node(cptab, cpt));
> > - if (!ret) {
> > - WARN_ON(!(flags & (__GFP_FS | __GFP_HIGH)));
> > - ret = vmalloc_node(size, cfs_cpt_spread_node(cptab, cpt));
> > - }
> > -
> > - return ret;
> > + return kvzalloc_node(size, flags, cfs_cpt_spread_node(cptab, cpt));
> > }
> > EXPORT_SYMBOL(libcfs_kvzalloc_cpt);
> > diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
> > index 6890897a6f30..10f1ef582659 100644
> > --- a/drivers/xen/evtchn.c
> > +++ b/drivers/xen/evtchn.c
> > @@ -87,18 +87,6 @@ struct user_evtchn {
> > bool enabled;
> > };
> >
> > -static evtchn_port_t *evtchn_alloc_ring(unsigned int size)
> > -{
> > - evtchn_port_t *ring;
> > - size_t s = size * sizeof(*ring);
> > -
> > - ring = kmalloc(s, GFP_KERNEL);
> > - if (!ring)
> > - ring = vmalloc(s);
> > -
> > - return ring;
> > -}
> > -
> > static void evtchn_free_ring(evtchn_port_t *ring)
> > {
> > kvfree(ring);
> > @@ -334,7 +322,7 @@ static int evtchn_resize_ring(struct per_user_data *u)
> > else
> > new_size = 2 * u->ring_size;
> >
> > - new_ring = evtchn_alloc_ring(new_size);
> > + new_ring = kvmalloc(new_size * sizeof(*new_ring), GFP_KERNEL);
> > if (!new_ring)
> > return -ENOMEM;
> >
> > diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
> > index 146b2dc0d2cf..4fc9712d927d 100644
> > --- a/fs/btrfs/ctree.c
> > +++ b/fs/btrfs/ctree.c
> > @@ -5391,13 +5391,10 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
> > goto out;
> > }
> >
> > - tmp_buf = kmalloc(fs_info->nodesize, GFP_KERNEL | __GFP_NOWARN);
> > + tmp_buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
> > if (!tmp_buf) {
> > - tmp_buf = vmalloc(fs_info->nodesize);
> > - if (!tmp_buf) {
> > - ret = -ENOMEM;
> > - goto out;
> > - }
> > + ret = -ENOMEM;
> > + goto out;
> > }
> >
> > left_path->search_commit_root = 1;
> > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> > index 77dabfed3a5d..6f0b488c7428 100644
> > --- a/fs/btrfs/ioctl.c
> > +++ b/fs/btrfs/ioctl.c
> > @@ -3547,12 +3547,9 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
> > u64 last_dest_end = destoff;
> >
> > ret = -ENOMEM;
> > - buf = kmalloc(fs_info->nodesize, GFP_KERNEL | __GFP_NOWARN);
> > - if (!buf) {
> > - buf = vmalloc(fs_info->nodesize);
> > - if (!buf)
> > - return ret;
> > - }
> > + buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
> > + if (!buf)
> > + return ret;
> >
> > path = btrfs_alloc_path();
> > if (!path) {
> > diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
> > index d145ce804620..0621ca2a7b5d 100644
> > --- a/fs/btrfs/send.c
> > +++ b/fs/btrfs/send.c
> > @@ -6242,22 +6242,16 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
> > sctx->clone_roots_cnt = arg->clone_sources_count;
> >
> > sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
> > - sctx->send_buf = kmalloc(sctx->send_max_size, GFP_KERNEL | __GFP_NOWARN);
> > + sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
> > if (!sctx->send_buf) {
> > - sctx->send_buf = vmalloc(sctx->send_max_size);
> > - if (!sctx->send_buf) {
> > - ret = -ENOMEM;
> > - goto out;
> > - }
> > + ret = -ENOMEM;
> > + goto out;
> > }
> >
> > - sctx->read_buf = kmalloc(BTRFS_SEND_READ_SIZE, GFP_KERNEL | __GFP_NOWARN);
> > + sctx->read_buf = kvmalloc(BTRFS_SEND_READ_SIZE, GFP_KERNEL);
> > if (!sctx->read_buf) {
> > - sctx->read_buf = vmalloc(BTRFS_SEND_READ_SIZE);
> > - if (!sctx->read_buf) {
> > - ret = -ENOMEM;
> > - goto out;
> > - }
> > + ret = -ENOMEM;
> > + goto out;
> > }
> >
> > sctx->pending_dir_moves = RB_ROOT;
> > @@ -6278,13 +6272,10 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
> > alloc_size = arg->clone_sources_count * sizeof(*arg->clone_sources);
> >
> > if (arg->clone_sources_count) {
> > - clone_sources_tmp = kmalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN);
> > + clone_sources_tmp = kvmalloc(alloc_size, GFP_KERNEL);
> > if (!clone_sources_tmp) {
> > - clone_sources_tmp = vmalloc(alloc_size);
> > - if (!clone_sources_tmp) {
> > - ret = -ENOMEM;
> > - goto out;
> > - }
> > + ret = -ENOMEM;
> > + goto out;
> > }
> >
> > ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
> > diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> > index 045d30d26624..78b18acf33ba 100644
> > --- a/fs/ceph/file.c
> > +++ b/fs/ceph/file.c
> > @@ -74,12 +74,9 @@ dio_get_pages_alloc(const struct iov_iter *it, size_t nbytes,
> > align = (unsigned long)(it->iov->iov_base + it->iov_offset) &
> > (PAGE_SIZE - 1);
> > npages = calc_pages_for(align, nbytes);
> > - pages = kmalloc(sizeof(*pages) * npages, GFP_KERNEL);
> > - if (!pages) {
> > - pages = vmalloc(sizeof(*pages) * npages);
> > - if (!pages)
> > - return ERR_PTR(-ENOMEM);
> > - }
> > + pages = kvmalloc(sizeof(*pages) * npages, GFP_KERNEL);
> > + if (!pages)
> > + return ERR_PTR(-ENOMEM);
>
> ceph hunk looks fine:
>
> Acked-by: Ilya Dryomov <idryomov@xxxxxxxxx>

thanks!

[...]

> However I noticed that in some cases you've dropped the zeroing part:
> fq_codel_init() and hhf_zalloc() zeroed both k and v, and some others
> were inconsistent and zeroed only k. Given that the fallback branch
> was probably dead, I'd keep the k behaviour. Was that intentional?

No, that is an omission. Thanks for noticing. I will send the updated
patch.
--
Michal Hocko
SUSE Labs