Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

[pandora-kernel.git] / fs / ocfs2 / extent_map.c

diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index 23457b4..2f5b92e 100644 (file)
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -832,6 +832,102 @@ out:
        return ret;
 }
 
+int ocfs2_seek_data_hole_offset(struct file *file, loff_t *offset, int origin)
+{
+       struct inode *inode = file->f_mapping->host;
+       int ret;
+       unsigned int is_last = 0, is_data = 0;
+       u16 cs_bits = OCFS2_SB(inode->i_sb)->s_clustersize_bits;
+       u32 cpos, cend, clen, hole_size;
+       u64 extoff, extlen;
+       struct buffer_head *di_bh = NULL;
+       struct ocfs2_extent_rec rec;
+
+       BUG_ON(origin != SEEK_DATA && origin != SEEK_HOLE);
+
+       ret = ocfs2_inode_lock(inode, &di_bh, 0);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       down_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+       if (*offset >= inode->i_size) {
+               ret = -ENXIO;
+               goto out_unlock;
+       }
+
+       if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
+               if (origin == SEEK_HOLE)
+                       *offset = inode->i_size;
+               goto out_unlock;
+       }
+
+       clen = 0;
+       cpos = *offset >> cs_bits;
+       cend = ocfs2_clusters_for_bytes(inode->i_sb, inode->i_size);
+
+       while (cpos < cend && !is_last) {
+               ret = ocfs2_get_clusters_nocache(inode, di_bh, cpos, &hole_size,
+                                                &rec, &is_last);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out_unlock;
+               }
+
+               extoff = cpos;
+               extoff <<= cs_bits;
+
+               if (rec.e_blkno == 0ULL) {
+                       clen = hole_size;
+                       is_data = 0;
+               } else {
+                       clen = le16_to_cpu(rec.e_leaf_clusters) -
+                               (cpos - le32_to_cpu(rec.e_cpos));
+                       is_data = (rec.e_flags & OCFS2_EXT_UNWRITTEN) ?  0 : 1;
+               }
+
+               if ((!is_data && origin == SEEK_HOLE) ||
+                   (is_data && origin == SEEK_DATA)) {
+                       if (extoff > *offset)
+                               *offset = extoff;
+                       goto out_unlock;
+               }
+
+               if (!is_last)
+                       cpos += clen;
+       }
+
+       if (origin == SEEK_HOLE) {
+               extoff = cpos;
+               extoff <<= cs_bits;
+               extlen = clen;
+               extlen <<=  cs_bits;
+
+               if ((extoff + extlen) > inode->i_size)
+                       extlen = inode->i_size - extoff;
+               extoff += extlen;
+               if (extoff > *offset)
+                       *offset = extoff;
+               goto out_unlock;
+       }
+
+       ret = -ENXIO;
+
+out_unlock:
+
+       brelse(di_bh);
+
+       up_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+       ocfs2_inode_unlock(inode, 0);
+out:
+       if (ret && ret != -ENXIO)
+               ret = -ENXIO;
+       return ret;
+}
+
 int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
                           struct buffer_head *bhs[], int flags,
                           int (*validate)(struct super_block *sb,