[PATCH 2/6] proc: commit to genradix

From: Kent Overstreet
Date: Tue May 22 2018 - 20:26:45 EST


the new generic radix trees have a simpler API and implementation, and
no limitations on number of elements, so all flex_array users are being
converted

Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
fs/proc/base.c | 48 +++++++++++++++++-------------------------------
1 file changed, 17 insertions(+), 31 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 9298324325..0a762eda64 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>
#ifdef CONFIG_HARDWALL
#include <asm/hardwall.h>
@@ -2140,11 +2140,12 @@ 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)
@@ -2176,35 +2177,21 @@ 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;
+ goto out_put_mm;
}
- 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);

@@ -2212,7 +2199,7 @@ 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,
@@ -2222,13 +2209,12 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
break;
ctx->pos++;
}
- if (fa)
- flex_array_free(fa);
+out_put_mm:
mmput(mm);
-
out_put_task:
put_task_struct(task);
out:
+ genradix_free(&fa);
return ret;
}

--
2.17.0