115e19c53501edc11f730191f7f047736815ae3d is the first bad commit commit 115e19c53501edc11f730191f7f047736815ae3d Author: Boaz Harrosh <Boaz Harrosh bharrosh@xxxxxxxxxxx> exofs: Set i_mapping->backing_dev_info anyway OK It's stupid ME. But why please someone explain this issue? For now I'll send a revert, but I would like this explained, perhaps a more solid fix is needed. Please look at this patch: diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c index 24ab327..0ba9886 100644 --- a/fs/exofs/inode.c +++ b/fs/exofs/inode.c @@ -1030,6 +1030,7 @@ struct inode *exofs_iget(struct super_block *sb, unsigned long ino) memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data)); } + inode->i_mapping->backing_dev_info = sb->s_bdi; if (S_ISREG(inode->i_mode)) { inode->i_op = &exofs_file_inode_operations; inode->i_fop = &exofs_file_operations; @@ -1129,6 +1130,7 @@ struct inode *exofs_new_inode(struct inode *dir, int mode) sbi = sb->s_fs_info; + inode->i_mapping->backing_dev_info = sb->s_bdi; sb->s_dirt = 1; inode_init_owner(inode, dir, mode); inode->i_ino = sbi->s_nextid++; All it does is set the inode's bdi to point to the super-block bdi. In stead of this default "null" bdi from VFS. When we do so the read-ahead stops coming, completely. Is there something that needs to be implemented farther for a super-block's bdi to support read-ahead? Please help? Thanks Boaz -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html