253 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			253 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Created (MFS based):
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|  *   February 2010 (Evgeniy Ivanov)
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|  */
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| 
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| #include "fs.h"
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| #include <fcntl.h>
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| #include <string.h>
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| #include <minix/com.h>
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| #include <sys/stat.h>
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| #include "buf.h"
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| #include "inode.h"
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| #include "super.h"
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| #include <minix/vfsif.h>
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| #include <minix/bdev.h>
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| 
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| 
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| /*===========================================================================*
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|  *				fs_readsuper				     *
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|  *===========================================================================*/
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| PUBLIC int fs_readsuper()
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| {
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| /* This function reads the superblock of the partition, gets the root inode
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|  * and sends back the details of them. Note, that the FS process does not
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|  * know the index of the vmnt object which refers to it, whenever the pathname
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|  * lookup leaves a partition an ELEAVEMOUNT error is transferred back
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|  * so that the VFS knows that it has to find the vnode on which this FS
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|  * process' partition is mounted on.
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|  */
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|   struct inode *root_ip;
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|   cp_grant_id_t label_gid;
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|   size_t label_len;
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|   int r = OK;
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|   int readonly, isroot;
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|   u32_t mask;
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| 
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|   fs_dev    = fs_m_in.REQ_DEV;
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|   label_gid = fs_m_in.REQ_GRANT;
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|   label_len = fs_m_in.REQ_PATH_LEN;
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|   readonly  = (fs_m_in.REQ_FLAGS & REQ_RDONLY) ? 1 : 0;
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|   isroot    = (fs_m_in.REQ_FLAGS & REQ_ISROOT) ? 1 : 0;
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| 
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|   if (label_len > sizeof(fs_dev_label))
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| 	return(EINVAL);
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| 
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|   r = sys_safecopyfrom(fs_m_in.m_source, label_gid, 0,
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| 		       (vir_bytes)fs_dev_label, label_len, D);
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|   if (r != OK) {
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| 	printf("%s:%d fs_readsuper: safecopyfrom failed: %d\n",
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| 	       __FILE__, __LINE__, r);
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| 	return(EINVAL);
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|   }
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| 
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|   /* Map the driver label for this major. */
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|   bdev_driver(fs_dev, fs_dev_label);
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| 
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|   /* Open the device the file system lives on. */
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|   if (bdev_open(fs_dev, readonly ? R_BIT : (R_BIT|W_BIT)) != OK) {
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|         return(EINVAL);
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|   }
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| 
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|   /* Fill in the super block. */
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|   STATICINIT(superblock, 1);
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|   if (!superblock)
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| 	panic("Can't allocate memory for superblock.");
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|   superblock->s_dev = fs_dev;	/* read_super() needs to know which dev */
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|   r = read_super(superblock);
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| 
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|   /* Is it recognized as a Minix filesystem? */
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|   if (r != OK) {
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| 	superblock->s_dev = NO_DEV;
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| 	bdev_close(fs_dev);
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| 	return(r);
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|   }
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| 
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|   if (superblock->s_rev_level != EXT2_GOOD_OLD_REV) {
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| 	struct super_block *sp = superblock; /* just shorter name */
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| 	mask = ~SUPPORTED_INCOMPAT_FEATURES;
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| 	if (HAS_INCOMPAT_FEATURE(sp, mask)) {
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| 		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_COMPRESSION & mask))
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| 			printf("ext2: fs compression is not supported by server\n");
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| 		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_FILETYPE & mask))
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| 			printf("ext2: fs in dir filetype is not supported by server\n");
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| 		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_RECOVER & mask))
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| 			printf("ext2: fs recovery is not supported by server\n");
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| 		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_JOURNAL_DEV & mask))
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| 			printf("ext2: fs journal dev is not supported by server\n");
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| 		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_META_BG & mask))
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| 			printf("ext2: fs meta bg is not supported by server\n");
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| 		return(EINVAL);
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| 	}
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| 	mask = ~SUPPORTED_RO_COMPAT_FEATURES;
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| 	if (HAS_RO_COMPAT_FEATURE(sp, mask)) {
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| 		if (HAS_RO_COMPAT_FEATURE(sp, RO_COMPAT_SPARSE_SUPER & mask)) {
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| 			printf("ext2: sparse super is not supported by server, \
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| 				remount read-only\n");
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| 		}
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| 		if (HAS_RO_COMPAT_FEATURE(sp, RO_COMPAT_LARGE_FILE & mask)) {
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| 			printf("ext2: large files are not supported by server, \
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| 				remount read-only\n");
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| 		}
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| 		if (HAS_RO_COMPAT_FEATURE(sp, RO_COMPAT_BTREE_DIR & mask)) {
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| 			printf("ext2: dir's btree is not supported by server, \
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| 				remount read-only\n");
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| 		}
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| 		return(EINVAL);
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| 	}
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|   }
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| 
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|   if (superblock->s_state == EXT2_ERROR_FS) {
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| 	printf("ext2: filesystem wasn't cleanly unmounted previous time\n");
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|         superblock->s_dev = NO_DEV;
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| 	bdev_close(fs_dev);
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| 	return(EINVAL);
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|   }
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| 
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| 
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|   set_blocksize(superblock->s_block_size,
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|   	superblock->s_blocks_count,
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| 	superblock->s_free_blocks_count,
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| 	major(fs_dev));
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| 
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|   /* Get the root inode of the mounted file system. */
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|   if ( (root_ip = get_inode(fs_dev, ROOT_INODE)) == NULL)  {
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| 	printf("ext2: couldn't get root inode\n");
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| 	superblock->s_dev = NO_DEV;
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| 	bdev_close(fs_dev);
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| 	return(EINVAL);
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|   }
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| 
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|   if (root_ip != NULL && root_ip->i_mode == 0) {
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| 	printf("%s:%d zero mode for root inode?\n", __FILE__, __LINE__);
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| 	put_inode(root_ip);
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| 	superblock->s_dev = NO_DEV;
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| 	bdev_close(fs_dev);
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| 	return(EINVAL);
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|   }
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| 
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|   if (root_ip != NULL && (root_ip->i_mode & I_TYPE) != I_DIRECTORY) {
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| 	printf("%s:%d root inode has wrong type, it's not a DIR\n",
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| 		 __FILE__, __LINE__);
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| 	put_inode(root_ip);
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| 	superblock->s_dev = NO_DEV;
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| 	bdev_close(fs_dev);
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| 	return(EINVAL);
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|   }
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| 
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|   superblock->s_rd_only = readonly;
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|   superblock->s_is_root = isroot;
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| 
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|   if (!readonly) {
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| 	superblock->s_state = EXT2_ERROR_FS;
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| 	superblock->s_mnt_count++;
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| 	superblock->s_mtime = clock_time();
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| 	write_super(superblock); /* Commit info, we just set above */
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|   }
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| 
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|   /* Root inode properties */
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|   fs_m_out.RES_INODE_NR = root_ip->i_num;
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|   fs_m_out.RES_MODE = root_ip->i_mode;
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|   fs_m_out.RES_FILE_SIZE_LO = root_ip->i_size;
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|   fs_m_out.RES_UID = root_ip->i_uid;
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|   fs_m_out.RES_GID = root_ip->i_gid;
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| 
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|   fs_m_out.RES_CONREQS = 1;	/* We can handle only 1 request at a time */
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| 
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|   return(r);
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| }
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| 
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| 
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| /*===========================================================================*
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|  *				fs_mountpoint				     *
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|  *===========================================================================*/
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| PUBLIC int fs_mountpoint()
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| {
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| /* This function looks up the mount point, it checks the condition whether
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|  * the partition can be mounted on the inode or not.
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|  */
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|   register struct inode *rip;
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|   int r = OK;
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|   mode_t bits;
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| 
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|   /* Temporarily open the file. */
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|   if( (rip = get_inode(fs_dev, fs_m_in.REQ_INODE_NR)) == NULL)
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| 	  return(EINVAL);
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| 
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| 
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|   if(rip->i_mountpoint) r = EBUSY;
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| 
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|   /* It may not be special. */
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|   bits = rip->i_mode & I_TYPE;
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|   if (bits == I_BLOCK_SPECIAL || bits == I_CHAR_SPECIAL) r = ENOTDIR;
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| 
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|   put_inode(rip);
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| 
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|   if(r == OK) rip->i_mountpoint = TRUE;
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| 
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|   return(r);
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| }
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| 
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| 
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| /*===========================================================================*
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|  *				fs_unmount				     *
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|  *===========================================================================*/
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| PUBLIC int fs_unmount()
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| {
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| /* Unmount a file system by device number. */
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|   int count;
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|   struct inode *rip, *root_ip;
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| 
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|   if(superblock->s_dev != fs_dev) return(EINVAL);
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| 
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|   /* See if the mounted device is busy.  Only 1 inode using it should be
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|    * open --the root inode-- and that inode only 1 time. */
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|   count = 0;
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|   for (rip = &inode[0]; rip < &inode[NR_INODES]; rip++)
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| 	  if (rip->i_count > 0 && rip->i_dev == fs_dev) count += rip->i_count;
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| 
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|   if ((root_ip = find_inode(fs_dev, ROOT_INODE)) == NULL) {
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| 	printf("ext2: couldn't find root inode. Unmount failed.\n");
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| 	panic("ext2: couldn't find root inode");
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| 	return(EINVAL);
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|   }
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| 
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|   /* Sync fs data before checking count. In some cases VFS can force unmounting
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|    * and it will damage unsynced FS. We don't sync before checking root_ip since
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|    * if it is missing then something strange happened with FS, so it's better
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|    * to not use possibly corrupted data for syncing.
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|    */
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|   if (!superblock->s_rd_only) {
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| 	/* force any cached blocks out of memory */
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| 	(void) fs_sync();
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|   }
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| 
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|   if (count > 1) return(EBUSY);	/* can't umount a busy file system */
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| 
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|   put_inode(root_ip);
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| 
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|   if (!superblock->s_rd_only) {
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| 	superblock->s_wtime = clock_time();
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| 	superblock->s_state = EXT2_VALID_FS;
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| 	write_super(superblock); /* Commit info, we just set above */
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|   }
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| 
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|   /* Close the device the file system lives on. */
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|   bdev_close(fs_dev);
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| 
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|   /* Finish off the unmount. */
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|   superblock->s_dev = NO_DEV;
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|   unmountdone = TRUE;
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| 
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|   return(OK);
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| }
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