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 /* A struct for the overall file system control.  Pointers to
33    jffs2_sb_info structs are named `c' in the source code.
34    Nee jffs_control
35 */
36 struct jffs2_sb_info {
37 	struct mtd_info *mtd;
38 
39 	uint32_t highest_ino;
40 	uint32_t checked_ino;
41 
42 	unsigned int flags;
43 
44 	struct task_struct *gc_task;	/* GC task struct */
45 	struct completion gc_thread_start; /* GC thread start completion */
46 	struct completion gc_thread_exit; /* GC thread exit completion port */
47 
48 	struct mutex alloc_sem;		/* Used to protect all the following
49 					   fields, and also to protect against
50 					   out-of-order writing of nodes. And GC. */
51 	uint32_t cleanmarker_size;	/* Size of an _inline_ CLEANMARKER
52 					 (i.e. zero for OOB CLEANMARKER */
53 
54 	uint32_t flash_size;
55 	uint32_t used_size;
56 	uint32_t dirty_size;
57 	uint32_t wasted_size;
58 	uint32_t free_size;
59 	uint32_t erasing_size;
60 	uint32_t bad_size;
61 	uint32_t sector_size;
62 	uint32_t unchecked_size;
63 
64 	uint32_t nr_free_blocks;
65 	uint32_t nr_erasing_blocks;
66 
67 	/* Number of free blocks there must be before we... */
68 	uint8_t resv_blocks_write;	/* ... allow a normal filesystem write */
69 	uint8_t resv_blocks_deletion;	/* ... allow a normal filesystem deletion */
70 	uint8_t resv_blocks_gctrigger;	/* ... wake up the GC thread */
71 	uint8_t resv_blocks_gcbad;	/* ... pick a block from the bad_list to GC */
72 	uint8_t resv_blocks_gcmerge;	/* ... merge pages when garbage collecting */
73 	/* Number of 'very dirty' blocks before we trigger immediate GC */
74 	uint8_t vdirty_blocks_gctrigger;
75 
76 	uint32_t nospc_dirty_size;
77 
78 	uint32_t nr_blocks;
79 	struct jffs2_eraseblock *blocks;	/* The whole array of blocks. Used for getting blocks
80 						 * from the offset (blocks[ofs / sector_size]) */
81 	struct jffs2_eraseblock *nextblock;	/* The block we're currently filling */
82 
83 	struct jffs2_eraseblock *gcblock;	/* The block we're currently garbage-collecting */
84 
85 	struct list_head clean_list;		/* Blocks 100% full of clean data */
86 	struct list_head very_dirty_list;	/* Blocks with lots of dirty space */
87 	struct list_head dirty_list;		/* Blocks with some dirty space */
88 	struct list_head erasable_list;		/* Blocks which are completely dirty, and need erasing */
89 	struct list_head erasable_pending_wbuf_list;	/* Blocks which need erasing but only after the current wbuf is flushed */
90 	struct list_head erasing_list;		/* Blocks which are currently erasing */
91 	struct list_head erase_checking_list;	/* Blocks which are being checked and marked */
92 	struct list_head erase_pending_list;	/* Blocks which need erasing now */
93 	struct list_head erase_complete_list;	/* Blocks which are erased and need the clean marker written to them */
94 	struct list_head free_list;		/* Blocks which are free and ready to be used */
95 	struct list_head bad_list;		/* Bad blocks. */
96 	struct list_head bad_used_list;		/* Bad blocks with valid data in. */
97 
98 	spinlock_t erase_completion_lock;	/* Protect free_list and erasing_list
99 						   against erase completion handler */
100 	wait_queue_head_t erase_wait;		/* For waiting for erases to complete */
101 
102 	wait_queue_head_t inocache_wq;
103 	int inocache_hashsize;
104 	struct jffs2_inode_cache **inocache_list;
105 	spinlock_t inocache_lock;
106 
107 	/* Sem to allow jffs2_garbage_collect_deletion_dirent to
108 	   drop the erase_completion_lock while it's holding a pointer
109 	   to an obsoleted node. I don't like this. Alternatives welcomed. */
110 	struct mutex erase_free_sem;
111 
112 	uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */
113 
114 #ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
115 	unsigned char *wbuf_verify; /* read-back buffer for verification */
116 #endif
117 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
118 	unsigned char *wbuf; /* Write-behind buffer for NAND flash */
119 	uint32_t wbuf_ofs;
120 	uint32_t wbuf_len;
121 	struct jffs2_inodirty *wbuf_inodes;
122 	struct rw_semaphore wbuf_sem;	/* Protects the write buffer */
123 
124 	unsigned char *oobbuf;
125 	int oobavail; /* How many bytes are available for JFFS2 in OOB */
126 #endif
127 
128 	struct jffs2_summary *summary;		/* Summary information */
129 
130 #ifdef CONFIG_JFFS2_FS_XATTR
131 #define XATTRINDEX_HASHSIZE	(57)
132 	uint32_t highest_xid;
133 	uint32_t highest_xseqno;
134 	struct list_head xattrindex[XATTRINDEX_HASHSIZE];
135 	struct list_head xattr_unchecked;
136 	struct list_head xattr_dead_list;
137 	struct jffs2_xattr_ref *xref_dead_list;
138 	struct jffs2_xattr_ref *xref_temp;
139 	struct rw_semaphore xattr_sem;
140 	uint32_t xdatum_mem_usage;
141 	uint32_t xdatum_mem_threshold;
142 #endif
143 	/* OS-private pointer for getting back to master superblock info */
144 	void *os_priv;
145 };
146 
147 #endif /* _JFFS2_FS_SB */
148