[GFS2] Fix a page lock / glock deadlock

[~andy/linux] / fs / gfs2 / ops_address.c

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 7523999afc53b4c1e7b2bf6fa4f398f57ed09b2d..fbb4a6aa15833f4aa040bec75e0d67bd8d294697 100644 (file)
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -508,23 +508,26 @@ static int __gfs2_readpage(void *file, struct page *page)
 static int gfs2_readpage(struct file *file, struct page *page)
 {
        struct gfs2_inode *ip = GFS2_I(page->mapping->host);
-       struct gfs2_holder gh;
+       struct gfs2_holder *gh;
        int error;
 
-       gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh);
-       error = gfs2_glock_nq_atime(&gh);
-       if (unlikely(error)) {
+       gh = gfs2_glock_is_locked_by_me(ip->i_gl);
+       if (!gh) {
+               gh = kmalloc(sizeof(struct gfs2_holder), GFP_NOFS);
+               if (!gh)
+                       return -ENOBUFS;
+               gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, gh);
                unlock_page(page);
-               goto out;
+               error = gfs2_glock_nq_atime(gh);
+               if (likely(error != 0))
+                       goto out;
+               return AOP_TRUNCATED_PAGE;
        }
        error = __gfs2_readpage(file, page);
-       gfs2_glock_dq(&gh);
+       gfs2_glock_dq(gh);
 out:
-       gfs2_holder_uninit(&gh);
-       if (error == GLR_TRYFAILED) {
-               yield();
-               return AOP_TRUNCATED_PAGE;
-       }
+       gfs2_holder_uninit(gh);
+       kfree(gh);
        return error;
 }
 
@@ -826,7 +829,7 @@ static int gfs2_write_end(struct file *file, struct address_space *mapping,
        unsigned int to = from + len;
        int ret;
 
-       BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == 0);
+       BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
 
        ret = gfs2_meta_inode_buffer(ip, &dibh);
        if (unlikely(ret)) {