mm/prfile.c

   1 /*
   2  * Mainly for aufs which mmap(2) diffrent file and wants to print different path
   3  * in /proc/PID/maps.
   4  * Call these functions via macros defined in linux/mm.h.
   5  *
   6  * See Documentation/filesystems/aufs/design/06mmap.txt
   7  *
   8  * Copyright (c) 2014 Junjro R. Okajima
   9  * Copyright (c) 2014 Ian Campbell
  10  */
  11
  12 #include <linux/mm.h>
  13 #include <linux/file.h>
  14 #include <linux/fs.h>
  15
  16 /* #define PRFILE_TRACE */
  17 static inline void prfile_trace(struct file *f, struct file *pr,
  18                               const char func[], int line, const char func2[])
  19 {
  20 #ifdef PRFILE_TRACE
  21         if (pr)
  22                 pr_info("%s:%d: %s, %s\n", func, line, func2,
  23                         f ? (char *)f->f_path.dentry->d_name.name : "(null)");
  24 #endif
  25 }
  26
  27 void vma_do_file_update_time(struct vm_area_struct *vma, const char func[],
  28                              int line)
  29 {
  30         struct file *f = vma->vm_file, *pr = vma->vm_prfile;
  31
  32         prfile_trace(f, pr, func, line, __func__);
  33         file_update_time(f);
  34         if (f && pr)
  35                 file_update_time(pr);
  36 }
  37
  38 struct file *vma_do_pr_or_file(struct vm_area_struct *vma, const char func[],
  39                                int line)
  40 {
  41         struct file *f = vma->vm_file, *pr = vma->vm_prfile;
  42
  43         prfile_trace(f, pr, func, line, __func__);
  44         return (f && pr) ? pr : f;
  45 }
  46
  47 void vma_do_get_file(struct vm_area_struct *vma, const char func[], int line)
  48 {
  49         struct file *f = vma->vm_file, *pr = vma->vm_prfile;
  50
  51         prfile_trace(f, pr, func, line, __func__);
  52         get_file(f);
  53         if (f && pr)
  54                 get_file(pr);
  55 }
  56
  57 void vma_do_fput(struct vm_area_struct *vma, const char func[], int line)
  58 {
  59         struct file *f = vma->vm_file, *pr = vma->vm_prfile;
  60
  61         prfile_trace(f, pr, func, line, __func__);
  62         fput(f);
  63         if (f && pr)
  64                 fput(pr);
  65 }
  66
  67 #ifndef CONFIG_MMU
  68 struct file *vmr_do_pr_or_file(struct vm_region *region, const char func[],
  69                                int line)
  70 {
  71         struct file *f = region->vm_file, *pr = region->vm_prfile;
  72
  73         prfile_trace(f, pr, func, line, __func__);
  74         return (f && pr) ? pr : f;
  75 }
  76
  77 void vmr_do_fput(struct vm_region *region, const char func[], int line)
  78 {
  79         struct file *f = region->vm_file, *pr = region->vm_prfile;
  80
  81         prfile_trace(f, pr, func, line, __func__);
  82         fput(f);
  83         if (f && pr)
  84                 fput(pr);
  85 }
  86 #endif /* !CONFIG_MMU */