process_vm_access: tidy up a bit

saner variable names, update linuxdoc comments, etc.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 15e4c2f..d6bd3fd 100644 (file)
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -23,20 +23,11 @@
 
 /**
  * process_vm_rw_pages - read/write pages from task specified
- * @task: task to read/write from
- * @mm: mm for task
- * @process_pages: struct pages area that can store at least
- *  nr_pages_to_copy struct page pointers
- * @pa: address of page in task to start copying from/to
+ * @pages: array of pointers to pages we want to copy
  * @start_offset: offset in page to start copying from/to
  * @len: number of bytes to copy
- * @lvec: iovec array specifying where to copy to/from
- * @lvec_cnt: number of elements in iovec array
- * @lvec_current: index in iovec array we are up to
- * @lvec_offset: offset in bytes from current iovec iov_base we are up to
+ * @iter: where to copy to/from locally
  * @vm_write: 0 means copy from, 1 means copy to
- * @nr_pages_to_copy: number of pages to copy
- * @bytes_copied: returns number of bytes successfully copied
  * Returns 0 on success, error code otherwise
  */
 static int process_vm_rw_pages(struct page **pages,
@@ -79,16 +70,12 @@ static int process_vm_rw_pages(struct page **pages,
  * process_vm_rw_single_vec - read/write pages from task specified
  * @addr: start memory address of target process
  * @len: size of area to copy to/from
- * @lvec: iovec array specifying where to copy to/from locally
- * @lvec_cnt: number of elements in iovec array
- * @lvec_current: index in iovec array we are up to
- * @lvec_offset: offset in bytes from current iovec iov_base we are up to
+ * @iter: where to copy to/from locally
  * @process_pages: struct pages area that can store at least
  *  nr_pages_to_copy struct page pointers
  * @mm: mm for task
  * @task: task to read/write from
  * @vm_write: 0 means copy from, 1 means copy to
- * @bytes_copied: returns number of bytes successfully copied
  * Returns 0 on success or on failure error code
  */
 static int process_vm_rw_single_vec(unsigned long addr,
@@ -103,7 +90,6 @@ static int process_vm_rw_single_vec(unsigned long addr,
        unsigned long start_offset = addr - pa;
        unsigned long nr_pages;
        ssize_t rc = 0;
-       unsigned long nr_pages_copied = 0;
        unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES
                / sizeof(struct pages *);
 
@@ -112,38 +98,32 @@ static int process_vm_rw_single_vec(unsigned long addr,
                return 0;
        nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1;
 
-       while ((nr_pages_copied < nr_pages) && iov_iter_count(iter)) {
-               int nr_pages_to_copy;
-               int pages_pinned;
-               size_t n;
-               nr_pages_to_copy = min(nr_pages - nr_pages_copied,
-                                      max_pages_per_loop);
+       while (!rc && nr_pages && iov_iter_count(iter)) {
+               int pages = min(nr_pages, max_pages_per_loop);
+               size_t bytes;
 
                /* Get the pages we're interested in */
                down_read(&mm->mmap_sem);
-               pages_pinned = get_user_pages(task, mm, pa,
-                                             nr_pages_to_copy,
-                                             vm_write, 0, process_pages, NULL);
+               pages = get_user_pages(task, mm, pa, pages,
+                                     vm_write, 0, process_pages, NULL);
                up_read(&mm->mmap_sem);
 
-               if (pages_pinned <= 0)
+               if (pages <= 0)
                        return -EFAULT;
 
-               n = pages_pinned * PAGE_SIZE - start_offset;
-               if (n > len)
-                       n = len;
+               bytes = pages * PAGE_SIZE - start_offset;
+               if (bytes > len)
+                       bytes = len;
 
                rc = process_vm_rw_pages(process_pages,
-                                        start_offset, n, iter,
+                                        start_offset, bytes, iter,
                                         vm_write);
-               len -= n;
+               len -= bytes;
                start_offset = 0;
-               nr_pages_copied += pages_pinned;
-               pa += pages_pinned * PAGE_SIZE;
-               while (pages_pinned)
-                       put_page(process_pages[--pages_pinned]);
-               if (rc < 0)
-                       break;
+               nr_pages -= pages;
+               pa += pages * PAGE_SIZE;
+               while (pages)
+                       put_page(process_pages[--pages]);
        }
 
        return rc;
@@ -156,8 +136,7 @@ static int process_vm_rw_single_vec(unsigned long addr,
 /**
  * process_vm_rw_core - core of reading/writing pages from task specified
  * @pid: PID of process to read/write from/to
- * @lvec: iovec array specifying where to copy to/from locally
- * @liovcnt: size of lvec array
+ * @iter: where to copy to/from locally
  * @rvec: iovec array specifying where to copy to/from in the other process
  * @riovcnt: size of rvec array
  * @flags: currently unused