1  /*
2   * JFFS2 -- Journalling Flash File System, Version 2.
3   *
4   * Copyright © 2001-2007 Red Hat, Inc.
5   * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6   *
7   * Created by David Woodhouse <dwmw2@infradead.org>
8   *
9   * For licensing information, see the file 'LICENCE' in this directory.
10   *
11   */
12  
13  #ifndef _JFFS2_FS_SB
14  #define _JFFS2_FS_SB
15  
16  #include <linux/types.h>
17  #include <linux/spinlock.h>
18  #include <linux/workqueue.h>
19  #include <linux/completion.h>
20  #include <linux/mutex.h>
21  #include <linux/timer.h>
22  #include <linux/wait.h>
23  #include <linux/list.h>
24  #include <linux/rwsem.h>
25  
26  #define JFFS2_SB_FLAG_RO 1
27  #define JFFS2_SB_FLAG_SCANNING 2 /* Flash scanning is in progress */
28  #define JFFS2_SB_FLAG_BUILDING 4 /* File system building is in progress */
29  
30  struct jffs2_inodirty;
31  
32  struct jffs2_mount_opts {
33  	bool override_compr;
34  	unsigned int compr;
35  
36  	/* The size of the reserved pool. The reserved pool is the JFFS2 flash
37  	 * space which may only be used by root cannot be used by the other
38  	 * users. This is implemented simply by means of not allowing the
39  	 * latter users to write to the file system if the amount if the
40  	 * available space is less then 'rp_size'. */
41  	bool set_rp_size;
42  	unsigned int rp_size;
43  };
44  
45  /* A struct for the overall file system control.  Pointers to
46     jffs2_sb_info structs are named `c' in the source code.
47     Nee jffs_control
48  */
49  struct jffs2_sb_info {
50  	struct mtd_info *mtd;
51  
52  	uint32_t highest_ino;
53  	uint32_t check_ino;		/* *NEXT* inode to be checked */
54  
55  	unsigned int flags;
56  
57  	struct task_struct *gc_task;	/* GC task struct */
58  	struct completion gc_thread_start; /* GC thread start completion */
59  	struct completion gc_thread_exit; /* GC thread exit completion port */
60  
61  	struct mutex alloc_sem;		/* Used to protect all the following
62  					   fields, and also to protect against
63  					   out-of-order writing of nodes. And GC. */
64  	uint32_t cleanmarker_size;	/* Size of an _inline_ CLEANMARKER
65  					 (i.e. zero for OOB CLEANMARKER */
66  
67  	uint32_t flash_size;
68  	uint32_t used_size;
69  	uint32_t dirty_size;
70  	uint32_t wasted_size;
71  	uint32_t free_size;
72  	uint32_t erasing_size;
73  	uint32_t bad_size;
74  	uint32_t sector_size;
75  	uint32_t unchecked_size;
76  
77  	uint32_t nr_free_blocks;
78  	uint32_t nr_erasing_blocks;
79  
80  	/* Number of free blocks there must be before we... */
81  	uint8_t resv_blocks_write;	/* ... allow a normal filesystem write */
82  	uint8_t resv_blocks_deletion;	/* ... allow a normal filesystem deletion */
83  	uint8_t resv_blocks_gctrigger;	/* ... wake up the GC thread */
84  	uint8_t resv_blocks_gcbad;	/* ... pick a block from the bad_list to GC */
85  	uint8_t resv_blocks_gcmerge;	/* ... merge pages when garbage collecting */
86  	/* Number of 'very dirty' blocks before we trigger immediate GC */
87  	uint8_t vdirty_blocks_gctrigger;
88  
89  	uint32_t nospc_dirty_size;
90  
91  	uint32_t nr_blocks;
92  	struct jffs2_eraseblock *blocks;	/* The whole array of blocks. Used for getting blocks
93  						 * from the offset (blocks[ofs / sector_size]) */
94  	struct jffs2_eraseblock *nextblock;	/* The block we're currently filling */
95  
96  	struct jffs2_eraseblock *gcblock;	/* The block we're currently garbage-collecting */
97  
98  	struct list_head clean_list;		/* Blocks 100% full of clean data */
99  	struct list_head very_dirty_list;	/* Blocks with lots of dirty space */
100  	struct list_head dirty_list;		/* Blocks with some dirty space */
101  	struct list_head erasable_list;		/* Blocks which are completely dirty, and need erasing */
102  	struct list_head erasable_pending_wbuf_list;	/* Blocks which need erasing but only after the current wbuf is flushed */
103  	struct list_head erasing_list;		/* Blocks which are currently erasing */
104  	struct list_head erase_checking_list;	/* Blocks which are being checked and marked */
105  	struct list_head erase_pending_list;	/* Blocks which need erasing now */
106  	struct list_head erase_complete_list;	/* Blocks which are erased and need the clean marker written to them */
107  	struct list_head free_list;		/* Blocks which are free and ready to be used */
108  	struct list_head bad_list;		/* Bad blocks. */
109  	struct list_head bad_used_list;		/* Bad blocks with valid data in. */
110  
111  	spinlock_t erase_completion_lock;	/* Protect free_list and erasing_list
112  						   against erase completion handler */
113  	wait_queue_head_t erase_wait;		/* For waiting for erases to complete */
114  
115  	wait_queue_head_t inocache_wq;
116  	int inocache_hashsize;
117  	struct jffs2_inode_cache **inocache_list;
118  	spinlock_t inocache_lock;
119  
120  	/* Sem to allow jffs2_garbage_collect_deletion_dirent to
121  	   drop the erase_completion_lock while it's holding a pointer
122  	   to an obsoleted node. I don't like this. Alternatives welcomed. */
123  	struct mutex erase_free_sem;
124  
125  	uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */
126  
127  #ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
128  	unsigned char *wbuf_verify; /* read-back buffer for verification */
129  #endif
130  #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
131  	unsigned char *wbuf; /* Write-behind buffer for NAND flash */
132  	uint32_t wbuf_ofs;
133  	uint32_t wbuf_len;
134  	struct jffs2_inodirty *wbuf_inodes;
135  	struct rw_semaphore wbuf_sem;	/* Protects the write buffer */
136  
137  	struct delayed_work wbuf_dwork; /* write-buffer write-out work */
138  
139  	unsigned char *oobbuf;
140  	int oobavail; /* How many bytes are available for JFFS2 in OOB */
141  #endif
142  
143  	struct jffs2_summary *summary;		/* Summary information */
144  	struct jffs2_mount_opts mount_opts;
145  
146  #ifdef CONFIG_JFFS2_FS_XATTR
147  #define XATTRINDEX_HASHSIZE	(57)
148  	uint32_t highest_xid;
149  	uint32_t highest_xseqno;
150  	struct list_head xattrindex[XATTRINDEX_HASHSIZE];
151  	struct list_head xattr_unchecked;
152  	struct list_head xattr_dead_list;
153  	struct jffs2_xattr_ref *xref_dead_list;
154  	struct jffs2_xattr_ref *xref_temp;
155  	struct rw_semaphore xattr_sem;
156  	uint32_t xdatum_mem_usage;
157  	uint32_t xdatum_mem_threshold;
158  #endif
159  	/* OS-private pointer for getting back to master superblock info */
160  	void *os_priv;
161  };
162  
163  #endif /* _JFFS2_FS_SB */
164