kclient: avoid leaving pages pinned in writepages

diff --git a/src/kernel/addr.c b/src/kernel/addr.c
index 33754cf06222a1a221bc2ffd96ab6f498738ab80..11d8784f156432d99838869f0468885392213b5a 100644 (file)
--- a/src/kernel/addr.c
+++ b/src/kernel/addr.c
@@ -158,6 +158,7 @@ static int ceph_writepages(struct address_space *mapping,
        int done = 0;
        int rc = 0;
        unsigned wsize = 1 << inode->i_blkbits;
+       int pinned = 0, locked = 0;
 
        if (client->mount_args.wsize && client->mount_args.wsize < wsize)
                wsize = client->mount_args.wsize;
@@ -220,6 +221,7 @@ retry:
                pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index,
                                                PAGECACHE_TAG_DIRTY,
                                                want);
+               pinned += pvec_pages;
                dout(30, "lookup_tag want %d got %d pages\n", want, pvec_pages);
        
                for (i = 0; i < pvec_pages; i++) {
@@ -262,6 +264,7 @@ retry:
                        dout(20, "writepages locked page %p index %lu\n",
                             page, page->index);
                        */
+                       locked++;
                        kmap(page);
                        if (pages)
                                pages[locked_pages] = page;
@@ -276,12 +279,20 @@ retry:
                if (locked_pages == 0)
                        break;
 
-               if (pages && pvec_pages && i == pvec_pages &&
-                   locked_pages &&
-                   locked_pages < max_pages) {
-                       dout(10, "reached end pvec, trying for more\n");
-                       pagevec_reinit(&pvec);
-                       goto get_more_pages;
+               if (pages) {
+                       int j;
+                       if (pvec_pages && i == pvec_pages &&
+                           locked_pages && locked_pages < max_pages) {
+                               dout(10, "reached end pvec, trying for more\n");
+                               pagevec_reinit(&pvec);
+                               goto get_more_pages;
+                       }
+
+                       /* shift unused pages over in the pvec...  we
+                        * will need to release them below. */
+                       for (j = i; j < pvec_pages; j++)
+                               pvec.pages[j-i] = pvec.pages[j];
+                       pvec.nr -= i;
                }
 
                /* did we get anything? */
@@ -310,6 +321,8 @@ retry:
                                        SetPageError(page);
                                kunmap(page);
                                unlock_page(page);
+                               BUG_ON(locked == 0);
+                               locked--;
                                end_page_writeback(page);
                        }                               
 
@@ -321,11 +334,15 @@ retry:
                }
                
                if (pages) {
-                       /* pagevec_release does lru_add_drain(); ...? */
+                       /* hmm, pagevec_release also does lru_add_drain()...? */
                        release_pages(pages, locked_pages, 0);  /* cold? */
-                       pagevec_reinit(&pvec);
-               } else
-                       pagevec_release(&pvec);
+                       pinned -= locked_pages;
+                       BUG_ON(pinned < 0);
+               }
+               pagevec_release(&pvec);
+               pinned -= pvec.nr;
+               BUG_ON(pinned != 0);
+               BUG_ON(locked != 0);
        }
        
        if (should_loop && !done) {
@@ -373,17 +390,14 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
                return 0;
 
        /* full page? */
-       if (pos_in_page == 0 && len == PAGE_SIZE) {  
-               SetPageUptodate(page);
+       if (pos_in_page == 0 && len == PAGE_SIZE)
                return 0;
-       }
        
        /* past end of file? */
        i_size = i_size_read(inode);
        if (page_off >= i_size || 
            (pos_in_page == 0 && (pos+len) >= i_size)) {
                simple_prepare_write(file, page, pos_in_page, pos_in_page+len);
-               SetPageUptodate(page);
                return 0;
        }
        
@@ -423,6 +437,7 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
        SetPageUptodate(page);
        set_page_dirty(page);
        unlock_page(page);
+       //page_cache_release(page);
 
        return copied;
 }