mm/prfile.c

   1 /*
   2  * Mainly for aufs which mmap(2) different file and wants to print different
   3  * path 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) 2014-2017 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, %pD2\n", func, line, func2, f);
  23 #endif
  24 }
  25
  26 void vma_do_file_update_time(struct vm_area_struct *vma, const char func[],
  27                              int line)
  28 {
  29         struct file *f = vma->vm_file, *pr = vma->vm_prfile;
  30
  31         prfile_trace(f, pr, func, line, __func__);
  32         file_update_time(f);
  33         if (f && pr)
  34                 file_update_time(pr);
  35 }
  36
  37 struct file *vma_do_pr_or_file(struct vm_area_struct *vma, const char func[],
  38                                int line)
  39 {
  40         struct file *f = vma->vm_file, *pr = vma->vm_prfile;
  41
  42         prfile_trace(f, pr, func, line, __func__);
  43         return (f && pr) ? pr : f;
  44 }
  45
  46 void vma_do_get_file(struct vm_area_struct *vma, const char func[], int line)
  47 {
  48         struct file *f = vma->vm_file, *pr = vma->vm_prfile;
  49
  50         prfile_trace(f, pr, func, line, __func__);
  51         get_file(f);
  52         if (f && pr)
  53                 get_file(pr);
  54 }
  55
  56 void vma_do_fput(struct vm_area_struct *vma, const char func[], int line)
  57 {
  58         struct file *f = vma->vm_file, *pr = vma->vm_prfile;
  59
  60         prfile_trace(f, pr, func, line, __func__);
  61         fput(f);
  62         if (f && pr)
  63                 fput(pr);
  64 }
  65
  66 #ifndef CONFIG_MMU
  67 struct file *vmr_do_pr_or_file(struct vm_region *region, const char func[],
  68                                int line)
  69 {
  70         struct file *f = region->vm_file, *pr = region->vm_prfile;
  71
  72         prfile_trace(f, pr, func, line, __func__);
  73         return (f && pr) ? pr : f;
  74 }
  75
  76 void vmr_do_fput(struct vm_region *region, const char func[], int line)
  77 {
  78         struct file *f = region->vm_file, *pr = region->vm_prfile;
  79
  80         prfile_trace(f, pr, func, line, __func__);
  81         fput(f);
  82         if (f && pr)
  83                 fput(pr);
  84 }
  85 #endif /* !CONFIG_MMU */