treewide: use kv[mz]alloc* rather than opencoded variants

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 <= 32kB (with 4kB pages) 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.

Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390
Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim
Acked-by: David Sterba <dsterba@suse.com> # btrfs
Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph
Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Santosh Raspatur <santosh@chelsio.com>
Cc: Hariprasad S <hariprasad@chelsio.com>
Cc: Yishai Hadas <yishaih@mellanox.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: "Yan, Zheng" <zyan@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

6 files changed, 28 insertions, 58 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 7dc8844037e0..1c3b6c54d5ee 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -5392,13 +5392,10 @@ 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 824b2390812f..72a7c856adc0 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3544,12 +3544,9 @@ 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 456c8901489b..030d592ed1fe 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -6355,22 +6355,16 @@ 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;
@@ -6391,13 +6385,10 @@ 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 26cc95421cca..18c045e2ead6 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);
 
 	for (idx = 0; idx < npages; ) {
 		size_t start;
diff --git a/fs/select.c b/fs/select.c
index e2112270d75a..4fc77e1e3980 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -586,10 +586,7 @@ int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
 			goto out_nofds;
 
 		alloc_size = 6 * size;
-		bits = kmalloc(alloc_size, GFP_KERNEL|__GFP_NOWARN);
-		if (!bits && alloc_size > PAGE_SIZE)
-			bits = vmalloc(alloc_size);
-
+		bits = kvmalloc(alloc_size, GFP_KERNEL);
 		if (!bits)
 			goto out_nofds;
 	}
diff --git a/fs/xattr.c b/fs/xattr.c
index b9fb2a042cfa..9be54684e831 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -431,12 +431,9 @@ setxattr(struct dentry *d, const char __user *name, const void __user *value,
 	if (size) {
 		if (size > XATTR_SIZE_MAX)
 			return -E2BIG;
-		kvalue = kmalloc(size, GFP_KERNEL | __GFP_NOWARN);
-		if (!kvalue) {
-			kvalue = vmalloc(size);
-			if (!kvalue)
-				return -ENOMEM;
-		}
+		kvalue = kvmalloc(size, GFP_KERNEL);
+		if (!kvalue)
+			return -ENOMEM;
 		if (copy_from_user(kvalue, value, size)) {
 			error = -EFAULT;
 			goto out;
@@ -528,12 +525,9 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
 	if (size) {
 		if (size > XATTR_SIZE_MAX)
 			size = XATTR_SIZE_MAX;
-		kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
-		if (!kvalue) {
-			kvalue = vzalloc(size);
-			if (!kvalue)
-				return -ENOMEM;
-		}
+		kvalue = kvzalloc(size, GFP_KERNEL);
+		if (!kvalue)
+			return -ENOMEM;
 	}
 
 	error = vfs_getxattr(d, kname, kvalue, size);
@@ -613,12 +607,9 @@ listxattr(struct dentry *d, char __user *list, size_t size)
 	if (size) {
 		if (size > XATTR_LIST_MAX)
 			size = XATTR_LIST_MAX;
-		klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL);
-		if (!klist) {
-			klist = vmalloc(size);
-			if (!klist)
-				return -ENOMEM;
-		}
+		klist = kvmalloc(size, GFP_KERNEL);
+		if (!klist)
+			return -ENOMEM;
 	}
 
 	error = vfs_listxattr(d, klist, size);