Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

[sfrench/cifs-2.6.git] / fs / ocfs2 / uptodate.c

diff --git a/fs/ocfs2/uptodate.c b/fs/ocfs2/uptodate.c
index 04a684dfdd96be735036db62b4c67a1a7cb65197..39814b900fc0dda863895768dda78e1ab64afa45 100644 (file)
--- a/fs/ocfs2/uptodate.c
+++ b/fs/ocfs2/uptodate.c
@@ -69,7 +69,7 @@ struct ocfs2_meta_cache_item {
        sector_t        c_block;
 };
 
-static kmem_cache_t *ocfs2_uptodate_cachep = NULL;
+static struct kmem_cache *ocfs2_uptodate_cachep = NULL;
 
 void ocfs2_metadata_cache_init(struct inode *inode)
 {
@@ -206,7 +206,10 @@ static int ocfs2_buffer_cached(struct ocfs2_inode_info *oi,
 }
 
 /* Warning: even if it returns true, this does *not* guarantee that
- * the block is stored in our inode metadata cache. */
+ * the block is stored in our inode metadata cache. 
+ * 
+ * This can be called under lock_buffer()
+ */
 int ocfs2_buffer_uptodate(struct inode *inode,
                          struct buffer_head *bh)
 {
@@ -226,6 +229,16 @@ int ocfs2_buffer_uptodate(struct inode *inode,
        return ocfs2_buffer_cached(OCFS2_I(inode), bh);
 }
 
+/* 
+ * Determine whether a buffer is currently out on a read-ahead request.
+ * ip_io_sem should be held to serialize submitters with the logic here.
+ */
+int ocfs2_buffer_read_ahead(struct inode *inode,
+                           struct buffer_head *bh)
+{
+       return buffer_locked(bh) && ocfs2_buffer_cached(OCFS2_I(inode), bh);
+}
+
 /* Requires ip_lock */
 static void ocfs2_append_cache_array(struct ocfs2_caching_info *ci,
                                     sector_t block)
@@ -337,7 +350,7 @@ static void __ocfs2_set_buffer_uptodate(struct ocfs2_inode_info *oi,
             (unsigned long long)oi->ip_blkno,
             (unsigned long long)block, expand_tree);
 
-       new = kmem_cache_alloc(ocfs2_uptodate_cachep, GFP_KERNEL);
+       new = kmem_cache_alloc(ocfs2_uptodate_cachep, GFP_NOFS);
        if (!new) {
                mlog_errno(-ENOMEM);
                return;
@@ -349,7 +362,7 @@ static void __ocfs2_set_buffer_uptodate(struct ocfs2_inode_info *oi,
                 * has no way of tracking that. */
                for(i = 0; i < OCFS2_INODE_MAX_CACHE_ARRAY; i++) {
                        tree[i] = kmem_cache_alloc(ocfs2_uptodate_cachep,
-                                                  GFP_KERNEL);
+                                                  GFP_NOFS);
                        if (!tree[i]) {
                                mlog_errno(-ENOMEM);
                                goto out_free;
@@ -403,7 +416,11 @@ out_free:
  *
  * Note that this function may actually fail to insert the block if
  * memory cannot be allocated. This is not fatal however (but may
- * result in a performance penalty) */
+ * result in a performance penalty)
+ *
+ * Readahead buffers can be passed in here before the I/O request is
+ * completed.
+ */
 void ocfs2_set_buffer_uptodate(struct inode *inode,
                               struct buffer_head *bh)
 {