add mount cache in sm_read_super

diff --git a/lustre/smfs/super.c b/lustre/smfs/super.c
index b146001..8a86d82 100644 (file)
--- a/lustre/smfs/super.c
+++ b/lustre/smfs/super.c
@@ -17,8 +17,6 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/loop.h>
-//#include <linux/jbd.h>
-//#include <linux/ext3_fs.h>
 #include <linux/errno.h>
 #include "smfs_internal.h" 
 
@@ -43,13 +41,92 @@ static char *smfs_options(char *options, char **devstr, char **namestr)
        }
        return pos;
 }
+static int get_fd(struct file *filp)
+{
+       struct files_struct *files = current->files;    
+       int fd = 0;
+       
+       write_lock(&files->file_lock);
+       for (fd = 0; fd < files->max_fds; fd++) {
+               if(files->fd[fd] == filp) {
+                       write_unlock(&files->file_lock);
+                       return fd;      
+               }       
+       }
+       write_unlock(&files->file_lock);
+       RETURN(-1);
+}
+#define MAX_LOOP_DEVICES       256
+static char *parse_path2dev(struct super_block *sb, char *dev_path)
+{
+       struct file   *filp;
+       int i = 0, fd = 0, error = 0;
+       char *name = NULL;
+               
+       filp = filp_open(dev_path, 0, 0);
+       if (!filp) 
+               RETURN(NULL);
+
+       if (S_ISREG(filp->f_dentry->d_inode->i_mode)) {
+               /*here we must walk through all the snap cache to 
+                *find the loop device */
+               for (i = 0; i < MAX_LOOP_DEVICES; i++) {
+                       fd = get_fd(filp);
+                       error = sb->s_bdev->bd_op->ioctl(filp->f_dentry->d_inode, 
+                                                filp, LOOP_SET_FD,
+                                                 (unsigned long)&fd);
+                       if (!error) {
+                               filp_close(filp, current->files); 
+                               /*FIXME later, the loop file should 
+                                *be different for different system*/
+                               SM_ALLOC(name, strlen("/dev/loop/") + 2);
+                               sprintf(name, "dev/loop/%d", i);
+                               RETURN(name);                                   
+                       }
+               }
+       }
+       SM_ALLOC(name, strlen(dev_path) + 1);
+       memcpy(name, dev_path, strlen(dev_path) + 1);
+       filp_close(filp, current->files); 
+       RETURN(name);
+}
 extern struct super_operations smfs_super_ops;
 
-static struct super_block *sm_mount_cache(struct super_block *sb, 
-                                         char *devstr,
-                                         char *typestr)
+static int sm_mount_cache(struct super_block *sb, 
+                         char *devstr,
+                         char *typestr)
 {
-       return NULL;    
+       struct vfsmount *mnt;   
+       struct smfs_super_info *smb;
+       char *dev_name = NULL;
+       unsigned long page;
+       int     err = 0;
+       
+       dev_name = parse_path2dev(sb, devstr);
+       if (!dev_name) {
+               GOTO(err_out, err = -ENOMEM);
+       }
+       if (!(page = __get_free_page(GFP_KERNEL))) {
+               GOTO(err_out, err = -ENOMEM);
+       }                                                                                                                                                   
+        memset((void *)page, 0, PAGE_SIZE);
+        sprintf((char *)page, "iopen_nopriv");
+                                                                                                                                                                                                     
+        mnt = do_kern_mount(typestr, 0, dev_name, (void *)page);
+        free_page(page);
+       
+       if (IS_ERR(mnt)) {
+                CERROR("do_kern_mount failed: rc = %d\n", err);
+                GOTO(err_out, 0);
+        }
+       smb = S2SMI(sb); 
+       smb->smsi_sb = mnt->mnt_sb;
+       smb->smsi_mnt = mnt;
+err_out:
+       if (dev_name) 
+               SM_FREE(dev_name, strlen(dev_name) + 2);
+               
+       return err;     
 }
 
 struct super_block *
@@ -59,10 +136,8 @@ smfs_read_super(
         int silent)
 {
        struct smfs_inode_info *smi;
-       struct smfs_super_info *smb;
        struct dentry *bottom_root;
        struct inode *root_inode = NULL;
-       struct super_block *cache_sb;
        char *devstr = NULL, *typestr = NULL;
        char *cache_data;
        ino_t root_ino;
@@ -84,17 +159,15 @@ smfs_read_super(
                GOTO(out_err, err=-EINVAL);
        }
        
-       cache_sb = sm_mount_cache(sb, devstr, typestr);
-       if (!cache_sb) {
+       err = sm_mount_cache(sb, devstr, typestr);
+       if (err) {
                CERROR("Can not mount %s as %s\n", devstr, typestr);
-               GOTO(out_err, err=-EINVAL);
+               GOTO(out_err, 0);
        }
        /* set up the super block */
-       smb = S2SMI(sb); 
-       smb->smsi_sb = cache_sb;
        sb->s_op = &smfs_super_ops;
 
-       bottom_root = dget(cache_sb->s_root);
+       bottom_root = dget(S2SMI(sb)->smsi_sb->s_root);
        if (!bottom_root) {
                CERROR("bottom not mounted\n");
                GOTO(out_err, err=-ENOENT);