In case of filesystem corruption, passing unchecked block numbers into sb_bread can result in an infinite loop in __getblk(). Introduce a wrapper function omfs_sbread() to check the block numbers and to also perform the clus_to_blk() scaling. Signed-off-by: Bob Copeland <me@bobcopeland.com>
		
			
				
	
	
		
			69 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			69 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _OMFS_H
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| #define _OMFS_H
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| 
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| #include <linux/module.h>
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| #include <linux/fs.h>
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| 
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| #include "omfs_fs.h"
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| 
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| /* In-memory structures */
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| struct omfs_sb_info {
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| 	u64 s_num_blocks;
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| 	u64 s_bitmap_ino;
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| 	u64 s_root_ino;
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| 	u32 s_blocksize;
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| 	u32 s_mirrors;
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| 	u32 s_sys_blocksize;
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| 	u32 s_clustersize;
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| 	int s_block_shift;
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| 	unsigned long **s_imap;
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| 	int s_imap_size;
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| 	struct mutex s_bitmap_lock;
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| 	int s_uid;
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| 	int s_gid;
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| 	int s_dmask;
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| 	int s_fmask;
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| };
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| 
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| /* convert a cluster number to a scaled block number */
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| static inline sector_t clus_to_blk(struct omfs_sb_info *sbi, sector_t block)
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| {
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| 	return block << sbi->s_block_shift;
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| }
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| 
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| static inline struct omfs_sb_info *OMFS_SB(struct super_block *sb)
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| {
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| 	return sb->s_fs_info;
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| }
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| 
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| /* bitmap.c */
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| extern unsigned long omfs_count_free(struct super_block *sb);
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| extern int omfs_allocate_block(struct super_block *sb, u64 block);
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| extern int omfs_allocate_range(struct super_block *sb, int min_request,
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| 			int max_request, u64 *return_block, int *return_size);
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| extern int omfs_clear_range(struct super_block *sb, u64 block, int count);
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| 
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| /* dir.c */
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| extern const struct file_operations omfs_dir_operations;
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| extern const struct inode_operations omfs_dir_inops;
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| extern int omfs_make_empty(struct inode *inode, struct super_block *sb);
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| extern int omfs_is_bad(struct omfs_sb_info *sbi, struct omfs_header *header,
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| 			u64 fsblock);
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| 
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| /* file.c */
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| extern const struct file_operations omfs_file_operations;
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| extern const struct inode_operations omfs_file_inops;
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| extern const struct address_space_operations omfs_aops;
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| extern void omfs_make_empty_table(struct buffer_head *bh, int offset);
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| extern int omfs_shrink_inode(struct inode *inode);
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| 
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| /* inode.c */
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| extern struct buffer_head *omfs_bread(struct super_block *sb, sector_t block);
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| extern struct inode *omfs_iget(struct super_block *sb, ino_t inode);
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| extern struct inode *omfs_new_inode(struct inode *dir, int mode);
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| extern int omfs_reserve_block(struct super_block *sb, sector_t block);
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| extern int omfs_find_empty_block(struct super_block *sb, int mode, ino_t *ino);
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| extern int omfs_sync_inode(struct inode *inode);
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| 
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| #endif
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