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 
37 /* A struct for the overall file system control.  Pointers to
38    jffs2_sb_info structs are named `c' in the source code.
39    Nee jffs_control
40 */
41 struct jffs2_sb_info {
42 	struct mtd_info *mtd;
43 
44 	uint32_t highest_ino;
45 	uint32_t checked_ino;
46 
47 	unsigned int flags;
48 
49 	struct task_struct *gc_task;	/* GC task struct */
50 	struct completion gc_thread_start; /* GC thread start completion */
51 	struct completion gc_thread_exit; /* GC thread exit completion port */
52 
53 	struct mutex alloc_sem;		/* Used to protect all the following
54 					   fields, and also to protect against
55 					   out-of-order writing of nodes. And GC. */
56 	uint32_t cleanmarker_size;	/* Size of an _inline_ CLEANMARKER
57 					 (i.e. zero for OOB CLEANMARKER */
58 
59 	uint32_t flash_size;
60 	uint32_t used_size;
61 	uint32_t dirty_size;
62 	uint32_t wasted_size;
63 	uint32_t free_size;
64 	uint32_t erasing_size;
65 	uint32_t bad_size;
66 	uint32_t sector_size;
67 	uint32_t unchecked_size;
68 
69 	uint32_t nr_free_blocks;
70 	uint32_t nr_erasing_blocks;
71 
72 	/* Number of free blocks there must be before we... */
73 	uint8_t resv_blocks_write;	/* ... allow a normal filesystem write */
74 	uint8_t resv_blocks_deletion;	/* ... allow a normal filesystem deletion */
75 	uint8_t resv_blocks_gctrigger;	/* ... wake up the GC thread */
76 	uint8_t resv_blocks_gcbad;	/* ... pick a block from the bad_list to GC */
77 	uint8_t resv_blocks_gcmerge;	/* ... merge pages when garbage collecting */
78 	/* Number of 'very dirty' blocks before we trigger immediate GC */
79 	uint8_t vdirty_blocks_gctrigger;
80 
81 	uint32_t nospc_dirty_size;
82 
83 	uint32_t nr_blocks;
84 	struct jffs2_eraseblock *blocks;	/* The whole array of blocks. Used for getting blocks
85 						 * from the offset (blocks[ofs / sector_size]) */
86 	struct jffs2_eraseblock *nextblock;	/* The block we're currently filling */
87 
88 	struct jffs2_eraseblock *gcblock;	/* The block we're currently garbage-collecting */
89 
90 	struct list_head clean_list;		/* Blocks 100% full of clean data */
91 	struct list_head very_dirty_list;	/* Blocks with lots of dirty space */
92 	struct list_head dirty_list;		/* Blocks with some dirty space */
93 	struct list_head erasable_list;		/* Blocks which are completely dirty, and need erasing */
94 	struct list_head erasable_pending_wbuf_list;	/* Blocks which need erasing but only after the current wbuf is flushed */
95 	struct list_head erasing_list;		/* Blocks which are currently erasing */
96 	struct list_head erase_checking_list;	/* Blocks which are being checked and marked */
97 	struct list_head erase_pending_list;	/* Blocks which need erasing now */
98 	struct list_head erase_complete_list;	/* Blocks which are erased and need the clean marker written to them */
99 	struct list_head free_list;		/* Blocks which are free and ready to be used */
100 	struct list_head bad_list;		/* Bad blocks. */
101 	struct list_head bad_used_list;		/* Bad blocks with valid data in. */
102 
103 	spinlock_t erase_completion_lock;	/* Protect free_list and erasing_list
104 						   against erase completion handler */
105 	wait_queue_head_t erase_wait;		/* For waiting for erases to complete */
106 
107 	wait_queue_head_t inocache_wq;
108 	int inocache_hashsize;
109 	struct jffs2_inode_cache **inocache_list;
110 	spinlock_t inocache_lock;
111 
112 	/* Sem to allow jffs2_garbage_collect_deletion_dirent to
113 	   drop the erase_completion_lock while it's holding a pointer
114 	   to an obsoleted node. I don't like this. Alternatives welcomed. */
115 	struct mutex erase_free_sem;
116 
117 	uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */
118 
119 #ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
120 	unsigned char *wbuf_verify; /* read-back buffer for verification */
121 #endif
122 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
123 	unsigned char *wbuf; /* Write-behind buffer for NAND flash */
124 	uint32_t wbuf_ofs;
125 	uint32_t wbuf_len;
126 	struct jffs2_inodirty *wbuf_inodes;
127 	struct rw_semaphore wbuf_sem;	/* Protects the write buffer */
128 
129 	unsigned char *oobbuf;
130 	int oobavail; /* How many bytes are available for JFFS2 in OOB */
131 #endif
132 
133 	struct jffs2_summary *summary;		/* Summary information */
134 	struct jffs2_mount_opts mount_opts;
135 
136 #ifdef CONFIG_JFFS2_FS_XATTR
137 #define XATTRINDEX_HASHSIZE	(57)
138 	uint32_t highest_xid;
139 	uint32_t highest_xseqno;
140 	struct list_head xattrindex[XATTRINDEX_HASHSIZE];
141 	struct list_head xattr_unchecked;
142 	struct list_head xattr_dead_list;
143 	struct jffs2_xattr_ref *xref_dead_list;
144 	struct jffs2_xattr_ref *xref_temp;
145 	struct rw_semaphore xattr_sem;
146 	uint32_t xdatum_mem_usage;
147 	uint32_t xdatum_mem_threshold;
148 #endif
149 	/* OS-private pointer for getting back to master superblock info */
150 	void *os_priv;
151 };
152 
153 #endif /* _JFFS2_FS_SB */
154