proc: commit to genradix

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

Link: http://lkml.kernel.org/r/20181217131929.11727-6-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 1b548d060d28ad9f5d950f865459b622555fd181..f5ebdd87afb244fefa0cd3342728e1ade5342d83 100644 (file)
--- 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;
 }