From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm: allow !GFP_KERNEL allocations for kvmalloc Support for GFP_NO{FS,IO} and __GFP_NOFAIL has been implemented by previous patches so we can allow the support for kvmalloc. This will allow some external users to simplify or completely remove their helpers. GFP_NOWAIT semantic hasn't been supported so far but it hasn't been explicitly documented so let's add a note about that. ceph_kvmalloc is the first helper to be dropped and changed to kvmalloc. Link: https://lkml.kernel.org/r/20211122153233.9924-5-mhocko@xxxxxxxxxx Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Cc: Ilya Dryomov <idryomov@xxxxxxxxx> Cc: Jeff Layton <jlayton@xxxxxxxxxx> Cc: Neil Brown <neilb@xxxxxxx> Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/ceph/libceph.h | 1 - mm/util.c | 15 ++++----------- net/ceph/buffer.c | 4 ++-- net/ceph/ceph_common.c | 27 --------------------------- net/ceph/crypto.c | 2 +- net/ceph/messenger.c | 2 +- net/ceph/messenger_v2.c | 2 +- net/ceph/osdmap.c | 12 ++++++------ 8 files changed, 15 insertions(+), 50 deletions(-) --- a/include/linux/ceph/libceph.h~mm-allow-gfp_kernel-allocations-for-kvmalloc +++ a/include/linux/ceph/libceph.h @@ -295,7 +295,6 @@ extern bool libceph_compatible(void *dat extern const char *ceph_msg_type_name(int type); extern int ceph_check_fsid(struct ceph_client *client, struct ceph_fsid *fsid); -extern void *ceph_kvmalloc(size_t size, gfp_t flags); struct fs_parameter; struct fc_log; --- a/mm/util.c~mm-allow-gfp_kernel-allocations-for-kvmalloc +++ a/mm/util.c @@ -549,13 +549,10 @@ EXPORT_SYMBOL(vm_mmap); * Uses kmalloc to get the memory but if the allocation fails then falls back * to the vmalloc allocator. Use kvfree for freeing the memory. * - * Reclaim modifiers - __GFP_NORETRY and __GFP_NOFAIL are not supported. + * GFP_NOWAIT and GFP_ATOMIC are not supported, neither is the __GFP_NORETRY modifier. * __GFP_RETRY_MAYFAIL is supported, and it should be used only if kmalloc is * preferable to the vmalloc fallback, due to visible performance drawbacks. * - * Please note that any use of gfp flags outside of GFP_KERNEL is careful to not - * fall back to vmalloc. - * * Return: pointer to the allocated memory of %NULL in case of failure */ void *kvmalloc_node(size_t size, gfp_t flags, int node) @@ -564,13 +561,6 @@ void *kvmalloc_node(size_t size, gfp_t f void *ret; /* - * vmalloc uses GFP_KERNEL for some internal allocations (e.g page tables) - * so the given set of flags has to be compatible. - */ - if ((flags & GFP_KERNEL) != GFP_KERNEL) - return kmalloc_node(size, flags, node); - - /* * We want to attempt a large physically contiguous block first because * it is less likely to fragment multiple larger blocks and therefore * contribute to a long term fragmentation less than vmalloc fallback. @@ -582,6 +572,9 @@ void *kvmalloc_node(size_t size, gfp_t f if (!(kmalloc_flags & __GFP_RETRY_MAYFAIL)) kmalloc_flags |= __GFP_NORETRY; + + /* nofail semantic is implemented by the vmalloc fallback */ + kmalloc_flags &= ~__GFP_NOFAIL; } ret = kmalloc_node(size, kmalloc_flags, node); --- a/net/ceph/buffer.c~mm-allow-gfp_kernel-allocations-for-kvmalloc +++ a/net/ceph/buffer.c @@ -7,7 +7,7 @@ #include <linux/ceph/buffer.h> #include <linux/ceph/decode.h> -#include <linux/ceph/libceph.h> /* for ceph_kvmalloc */ +#include <linux/ceph/libceph.h> /* for kvmalloc */ struct ceph_buffer *ceph_buffer_new(size_t len, gfp_t gfp) { @@ -17,7 +17,7 @@ struct ceph_buffer *ceph_buffer_new(size if (!b) return NULL; - b->vec.iov_base = ceph_kvmalloc(len, gfp); + b->vec.iov_base = kvmalloc(len, gfp); if (!b->vec.iov_base) { kfree(b); return NULL; --- a/net/ceph/ceph_common.c~mm-allow-gfp_kernel-allocations-for-kvmalloc +++ a/net/ceph/ceph_common.c @@ -190,33 +190,6 @@ int ceph_compare_options(struct ceph_opt } EXPORT_SYMBOL(ceph_compare_options); -/* - * kvmalloc() doesn't fall back to the vmalloc allocator unless flags are - * compatible with (a superset of) GFP_KERNEL. This is because while the - * actual pages are allocated with the specified flags, the page table pages - * are always allocated with GFP_KERNEL. - * - * ceph_kvmalloc() may be called with GFP_KERNEL, GFP_NOFS or GFP_NOIO. - */ -void *ceph_kvmalloc(size_t size, gfp_t flags) -{ - void *p; - - if ((flags & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS)) { - p = kvmalloc(size, flags); - } else if ((flags & (__GFP_IO | __GFP_FS)) == __GFP_IO) { - unsigned int nofs_flag = memalloc_nofs_save(); - p = kvmalloc(size, GFP_KERNEL); - memalloc_nofs_restore(nofs_flag); - } else { - unsigned int noio_flag = memalloc_noio_save(); - p = kvmalloc(size, GFP_KERNEL); - memalloc_noio_restore(noio_flag); - } - - return p; -} - static int parse_fsid(const char *str, struct ceph_fsid *fsid) { int i = 0; --- a/net/ceph/crypto.c~mm-allow-gfp_kernel-allocations-for-kvmalloc +++ a/net/ceph/crypto.c @@ -147,7 +147,7 @@ void ceph_crypto_key_destroy(struct ceph static const u8 *aes_iv = (u8 *)CEPH_AES_IV; /* - * Should be used for buffers allocated with ceph_kvmalloc(). + * Should be used for buffers allocated with kvmalloc(). * Currently these are encrypt out-buffer (ceph_buffer) and decrypt * in-buffer (msg front). * --- a/net/ceph/messenger.c~mm-allow-gfp_kernel-allocations-for-kvmalloc +++ a/net/ceph/messenger.c @@ -1920,7 +1920,7 @@ struct ceph_msg *ceph_msg_new2(int type, /* front */ if (front_len) { - m->front.iov_base = ceph_kvmalloc(front_len, flags); + m->front.iov_base = kvmalloc(front_len, flags); if (m->front.iov_base == NULL) { dout("ceph_msg_new can't allocate %d bytes\n", front_len); --- a/net/ceph/messenger_v2.c~mm-allow-gfp_kernel-allocations-for-kvmalloc +++ a/net/ceph/messenger_v2.c @@ -308,7 +308,7 @@ static void *alloc_conn_buf(struct ceph_ if (WARN_ON(con->v2.conn_buf_cnt >= ARRAY_SIZE(con->v2.conn_bufs))) return NULL; - buf = ceph_kvmalloc(len, GFP_NOIO); + buf = kvmalloc(len, GFP_NOIO); if (!buf) return NULL; --- a/net/ceph/osdmap.c~mm-allow-gfp_kernel-allocations-for-kvmalloc +++ a/net/ceph/osdmap.c @@ -980,7 +980,7 @@ static struct crush_work *alloc_workspac work_size = crush_work_size(c, CEPH_PG_MAX_SIZE); dout("%s work_size %zu bytes\n", __func__, work_size); - work = ceph_kvmalloc(work_size, GFP_NOIO); + work = kvmalloc(work_size, GFP_NOIO); if (!work) return NULL; @@ -1190,9 +1190,9 @@ static int osdmap_set_max_osd(struct cep if (max == map->max_osd) return 0; - state = ceph_kvmalloc(array_size(max, sizeof(*state)), GFP_NOFS); - weight = ceph_kvmalloc(array_size(max, sizeof(*weight)), GFP_NOFS); - addr = ceph_kvmalloc(array_size(max, sizeof(*addr)), GFP_NOFS); + state = kvmalloc(array_size(max, sizeof(*state)), GFP_NOFS); + weight = kvmalloc(array_size(max, sizeof(*weight)), GFP_NOFS); + addr = kvmalloc(array_size(max, sizeof(*addr)), GFP_NOFS); if (!state || !weight || !addr) { kvfree(state); kvfree(weight); @@ -1222,7 +1222,7 @@ static int osdmap_set_max_osd(struct cep if (map->osd_primary_affinity) { u32 *affinity; - affinity = ceph_kvmalloc(array_size(max, sizeof(*affinity)), + affinity = kvmalloc(array_size(max, sizeof(*affinity)), GFP_NOFS); if (!affinity) return -ENOMEM; @@ -1503,7 +1503,7 @@ static int set_primary_affinity(struct c if (!map->osd_primary_affinity) { int i; - map->osd_primary_affinity = ceph_kvmalloc( + map->osd_primary_affinity = kvmalloc( array_size(map->max_osd, sizeof(*map->osd_primary_affinity)), GFP_NOFS); if (!map->osd_primary_affinity) _