Merge to Fedora kernel-2.6.17-1.2187_FC5 patched with stable patch-2.6.17.13-vs2...

[linux-2.6.git] / mm / filemap.c

diff --git a/mm/filemap.c b/mm/filemap.c
index 4b04495..96f354e 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -518,18 +518,11 @@ EXPORT_SYMBOL(unlock_page);
  */
 void end_page_writeback(struct page *page)
 {
-       struct zone *zone = page_zone(page);
        if (!TestClearPageReclaim(page) || rotate_reclaimable_page(page)) {
                if (!test_clear_page_writeback(page))
                        BUG();
        }
        smp_mb__after_clear_bit();
-       if (zone->all_unreclaimable) {
-               spin_lock(&zone->lock);
-               zone->all_unreclaimable = 0;
-               zone->pages_scanned = 0;
-               spin_unlock(&zone->lock);
-       }
        wake_up_page(page, PG_writeback);
 }
 EXPORT_SYMBOL(end_page_writeback);
@@ -2022,14 +2015,21 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
        do {
                unsigned long index;
                unsigned long offset;
-               unsigned long maxlen;
                size_t copied;
 
                offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
                index = pos >> PAGE_CACHE_SHIFT;
                bytes = PAGE_CACHE_SIZE - offset;
-               if (bytes > count)
-                       bytes = count;
+
+               /* Limit the size of the copy to the caller's write size */
+               bytes = min(bytes, count);
+
+               /*
+                * Limit the size of the copy to that of the current segment,
+                * because fault_in_pages_readable() doesn't know how to walk
+                * segments.
+                */
+               bytes = min(bytes, cur_iov->iov_len - iov_base);
 
                /*
                 * Bring in the user page that we will copy from _first_.
@@ -2037,10 +2037,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
                 * same page as we're writing to, without it being marked
                 * up-to-date.
                 */
-               maxlen = cur_iov->iov_len - iov_base;
-               if (maxlen > bytes)
-                       maxlen = bytes;
-               fault_in_pages_readable(buf, maxlen);
+               fault_in_pages_readable(buf, bytes);
 
                page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec);
                if (!page) {
@@ -2048,6 +2045,12 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
                        break;
                }
 
+               if (unlikely(bytes == 0)) {
+                       status = 0;
+                       copied = 0;
+                       goto zero_length_segment;
+               }
+
                status = a_ops->prepare_write(file, page, offset, offset+bytes);
                if (unlikely(status)) {
                        loff_t isize = i_size_read(inode);
@@ -2077,7 +2080,8 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
                        page_cache_release(page);
                        continue;
                }
-               if (likely(copied > 0)) {
+zero_length_segment:
+               if (likely(copied >= 0)) {
                        if (!status)
                                status = copied;