process_vm_access: tidy up a bit

saner variable names, update linuxdoc comments, etc.

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

1 files changed, 19 insertions, 40 deletions

diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 15e4c2f312e8..d6bd3fdd6925 100644
--- 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