Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - a few misc things

 - the rest of MM

-  remove flex_arrays, replace with new simple radix-tree implementation

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (38 commits)
  Drop flex_arrays
  sctp: convert to genradix
  proc: commit to genradix
  generic radix trees
  selinux: convert to kvmalloc
  md: convert to kvmalloc
  openvswitch: convert to kvmalloc
  of: fix kmemleak crash caused by imbalance in early memory reservation
  mm: memblock: update comments and kernel-doc
  memblock: split checks whether a region should be skipped to a helper function
  memblock: remove memblock_{set,clear}_region_flags
  memblock: drop memblock_alloc_*_nopanic() variants
  memblock: memblock_alloc_try_nid: don't panic
  treewide: add checks for the return value of memblock_alloc*()
  swiotlb: add checks for the return value of memblock_alloc*()
  init/main: add checks for the return value of memblock_alloc*()
  mm/percpu: add checks for the return value of memblock_alloc*()
  sparc: add checks for the return value of memblock_alloc*()
  ia64: add checks for the return value of memblock_alloc*()
  arch: don't memset(0) memory returned by memblock_alloc()
  ...

6 files changed, 30 insertions, 42 deletions

diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index 48ce50484e80..10d3bd3f534b 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -92,7 +92,7 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
 		return ret;
 
 	if (v9ses->cache)
-		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE;
+		sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
 
 	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
 	if (!v9ses->cache)
diff --git a/fs/afs/super.c b/fs/afs/super.c
index dcd07fe99871..e684f6769b15 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -399,7 +399,7 @@ static int afs_fill_super(struct super_block *sb,
 	ret = super_setup_bdi(sb);
 	if (ret)
 		return ret;
-	sb->s_bdi->ra_pages	= VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
+	sb->s_bdi->ra_pages	= VM_READAHEAD_PAGES;
 
 	/* allocate the root inode and dentry */
 	if (as->dyn_root) {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f0cdb53f3e2d..6fe9197f6ee4 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2958,7 +2958,7 @@ int open_ctree(struct super_block *sb,
 	sb->s_bdi->congested_fn = btrfs_congested_fn;
 	sb->s_bdi->congested_data = fs_info;
 	sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
-	sb->s_bdi->ra_pages = VM_MAX_READAHEAD * SZ_1K / PAGE_SIZE;
+	sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
 	sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
 	sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
 
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index c2d4099429be..16750ed591ae 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1010,7 +1010,7 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 	if (err)
 		return err;
 
-	sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
+	sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
 	/* fuse does it's own writeback accounting */
 	sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 5d99376d2369..c88088d92613 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -923,7 +923,7 @@ static void io_async_list_note(int rw, struct io_kiocb *req, size_t len)
 		/* Use 8x RA size as a decent limiter for both reads/writes */
 		max_pages = filp->f_ra.ra_pages;
 		if (!max_pages)
-			max_pages = VM_MAX_READAHEAD >> (PAGE_SHIFT - 10);
+			max_pages = VM_READAHEAD_PAGES;
 		max_pages *= 8;
 
 		/* If max pages are exceeded, reset the state */
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 5ab1849971b4..f5ebdd87afb2 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -59,6 +59,7 @@
 #include <linux/capability.h>
 #include <linux/file.h>
 #include <linux/fdtable.h>
+#include <linux/generic-radix-tree.h>
 #include <linux/string.h>
 #include <linux/seq_file.h>
 #include <linux/namei.h>
@@ -92,7 +93,6 @@
 #include <linux/sched/coredump.h>
 #include <linux/sched/debug.h>
 #include <linux/sched/stat.h>
-#include <linux/flex_array.h>
 #include <linux/posix-timers.h>
 #include <trace/events/oom.h>
 #include "internal.h"
@@ -2142,11 +2142,12 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
 	struct task_struct *task;
 	struct mm_struct *mm;
 	unsigned long nr_files, pos, i;
-	struct flex_array *fa = NULL;
-	struct map_files_info info;
+	GENRADIX(struct map_files_info) fa;
 	struct map_files_info *p;
 	int ret;
 
+	genradix_init(&fa);
+
 	ret = -ENOENT;
 	task = get_proc_task(file_inode(file));
 	if (!task)
@@ -2178,35 +2179,22 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
 	 */
 
 	for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
-		if (vma->vm_file && ++pos > ctx->pos)
-			nr_files++;
-	}
+		if (!vma->vm_file)
+			continue;
+		if (++pos <= ctx->pos)
+			continue;
 
-	if (nr_files) {
-		fa = flex_array_alloc(sizeof(info), nr_files,
-					GFP_KERNEL);
-		if (!fa || flex_array_prealloc(fa, 0, nr_files,
-						GFP_KERNEL)) {
+		p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
+		if (!p) {
 			ret = -ENOMEM;
-			if (fa)
-				flex_array_free(fa);
 			up_read(&mm->mmap_sem);
 			mmput(mm);
 			goto out_put_task;
 		}
-		for (i = 0, vma = mm->mmap, pos = 2; vma;
-				vma = vma->vm_next) {
-			if (!vma->vm_file)
-				continue;
-			if (++pos <= ctx->pos)
-				continue;
 
-			info.start = vma->vm_start;
-			info.end = vma->vm_end;
-			info.mode = vma->vm_file->f_mode;
-			if (flex_array_put(fa, i++, &info, GFP_KERNEL))
-				BUG();
-		}
+		p->start = vma->vm_start;
+		p->end = vma->vm_end;
+		p->mode = vma->vm_file->f_mode;
 	}
 	up_read(&mm->mmap_sem);
 	mmput(mm);
@@ -2215,7 +2203,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
 		char buf[4 * sizeof(long) + 2];	/* max: %lx-%lx\0 */
 		unsigned int len;
 
-		p = flex_array_get(fa, i);
+		p = genradix_ptr(&fa, i);
 		len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
 		if (!proc_fill_cache(file, ctx,
 				      buf, len,
@@ -2225,12 +2213,11 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
 			break;
 		ctx->pos++;
 	}
-	if (fa)
-		flex_array_free(fa);
 
 out_put_task:
 	put_task_struct(task);
 out:
+	genradix_free(&fa);
 	return ret;
 }
 
@@ -2459,11 +2446,10 @@ static struct dentry *proc_pident_instantiate(struct dentry *dentry,
 
 static struct dentry *proc_pident_lookup(struct inode *dir, 
 					 struct dentry *dentry,
-					 const struct pid_entry *ents,
-					 unsigned int nents)
+					 const struct pid_entry *p,
+					 const struct pid_entry *end)
 {
 	struct task_struct *task = get_proc_task(dir);
-	const struct pid_entry *p, *last;
 	struct dentry *res = ERR_PTR(-ENOENT);
 
 	if (!task)
@@ -2473,8 +2459,7 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
 	 * Yes, it does not scale. And it should not. Don't add
 	 * new entries into /proc/<tgid>/ without very good reasons.
 	 */
-	last = &ents[nents];
-	for (p = ents; p < last; p++) {
+	for (; p < end; p++) {
 		if (p->len != dentry->d_name.len)
 			continue;
 		if (!memcmp(dentry->d_name.name, p->name, p->len)) {
@@ -2610,7 +2595,7 @@ static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
 { \
 	return proc_pident_lookup(dir, dentry, \
 				  LSM##_attr_dir_stuff, \
-				  ARRAY_SIZE(LSM##_attr_dir_stuff)); \
+				  LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
 } \
 \
 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
@@ -2655,7 +2640,8 @@ static struct dentry *proc_attr_dir_lookup(struct inode *dir,
 				struct dentry *dentry, unsigned int flags)
 {
 	return proc_pident_lookup(dir, dentry,
-				  attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
+				  attr_dir_stuff,
+				  attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
 }
 
 static const struct inode_operations proc_attr_dir_inode_operations = {
@@ -3091,7 +3077,8 @@ static const struct file_operations proc_tgid_base_operations = {
 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 {
 	return proc_pident_lookup(dir, dentry,
-				  tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
+				  tgid_base_stuff,
+				  tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
 }
 
 static const struct inode_operations proc_tgid_base_inode_operations = {
@@ -3463,7 +3450,8 @@ static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 {
 	return proc_pident_lookup(dir, dentry,
-				  tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
+				  tid_base_stuff,
+				  tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
 }
 
 static const struct file_operations proc_tid_base_operations = {