The svn.clkao.org server seems to be a bittle unstable. I am attaching the
patch.
Rafael
Index: mm/filemap.c
===================================================================
--- mm/filemap.c (revision 21992)
+++ mm/filemap.c (revision 21993)
@@ -722,7 +722,10 @@
offset = *ppos & ~PAGE_CACHE_MASK;
isize = i_size_read(inode);
- end_index = isize >> PAGE_CACHE_SHIFT;
+ if (!isize)
+ goto out;
+
+ end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
if (index > end_index)
goto out;
@@ -730,6 +733,16 @@
struct page *page;
unsigned long nr, ret;
+ /* nr is the maximum number of bytes to copy from this page */
+ nr = PAGE_CACHE_SIZE;
+ if (index == end_index) {
+ nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+ if (nr <= offset) {
+ goto out;
+ }
+ }
+ nr = nr - offset;
+
cond_resched();
page_cache_readahead(mapping, &ra, filp, index);
@@ -742,16 +755,6 @@
if (!PageUptodate(page))
goto page_not_up_to_date;
page_ok:
- /* nr is the maximum number of bytes to copy from this page */
- nr = PAGE_CACHE_SIZE;
- if (index == end_index) {
- nr = isize & ~PAGE_CACHE_MASK;
- if (nr <= offset) {
- page_cache_release(page);
- goto out;
- }
- }
- nr = nr - offset;
/* If users can be writing to this page using arbitrary
* virtual addresses, take care about potential aliasing
@@ -827,11 +830,22 @@
* another truncate extends the file - this is desired though).
*/
isize = i_size_read(inode);
- end_index = isize >> PAGE_CACHE_SHIFT;
- if (index > end_index) {
+ end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+ if (unlikely(!isize || index > end_index)) {
page_cache_release(page);
goto out;
}
+
+ /* nr is the maximum number of bytes to copy from this page */
+ nr = PAGE_CACHE_SIZE;
+ if (index == end_index) {
+ nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+ if (nr <= offset) {
+ page_cache_release(page);
+ goto out;
+ }
+ }
+ nr = nr - offset;
goto page_ok;
readpage_error:
