xref: /openbmc/linux/fs/btrfs/ordered-data.h (revision 6774def6)
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18 
19 #ifndef __BTRFS_ORDERED_DATA__
20 #define __BTRFS_ORDERED_DATA__
21 
22 /* one of these per inode */
23 struct btrfs_ordered_inode_tree {
24 	spinlock_t lock;
25 	struct rb_root tree;
26 	struct rb_node *last;
27 };
28 
29 struct btrfs_ordered_sum {
30 	/* bytenr is the start of this extent on disk */
31 	u64 bytenr;
32 
33 	/*
34 	 * this is the length in bytes covered by the sums array below.
35 	 */
36 	int len;
37 	struct list_head list;
38 	/* last field is a variable length array of csums */
39 	u32 sums[];
40 };
41 
42 /*
43  * bits for the flags field:
44  *
45  * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
46  * It is used to make sure metadata is inserted into the tree only once
47  * per extent.
48  *
49  * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
50  * rbtree, just before waking any waiters.  It is used to indicate the
51  * IO is done and any metadata is inserted into the tree.
52  */
53 #define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */
54 
55 #define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */
56 
57 #define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */
58 
59 #define BTRFS_ORDERED_COMPRESSED 3 /* writing a zlib compressed extent */
60 
61 #define BTRFS_ORDERED_PREALLOC 4 /* set when writing to prealloced extent */
62 
63 #define BTRFS_ORDERED_DIRECT 5 /* set when we're doing DIO with this extent */
64 
65 #define BTRFS_ORDERED_IOERR 6 /* We had an io error when writing this out */
66 
67 #define BTRFS_ORDERED_UPDATED_ISIZE 7 /* indicates whether this ordered extent
68 				       * has done its due diligence in updating
69 				       * the isize. */
70 #define BTRFS_ORDERED_LOGGED_CSUM 8 /* We've logged the csums on this ordered
71 				       ordered extent */
72 #define BTRFS_ORDERED_TRUNCATED 9 /* Set when we have to truncate an extent */
73 
74 struct btrfs_ordered_extent {
75 	/* logical offset in the file */
76 	u64 file_offset;
77 
78 	/* disk byte number */
79 	u64 start;
80 
81 	/* ram length of the extent in bytes */
82 	u64 len;
83 
84 	/* extent length on disk */
85 	u64 disk_len;
86 
87 	/* number of bytes that still need writing */
88 	u64 bytes_left;
89 
90 	/* number of bytes that still need csumming */
91 	u64 csum_bytes_left;
92 
93 	/*
94 	 * the end of the ordered extent which is behind it but
95 	 * didn't update disk_i_size. Please see the comment of
96 	 * btrfs_ordered_update_i_size();
97 	 */
98 	u64 outstanding_isize;
99 
100 	/*
101 	 * If we get truncated we need to adjust the file extent we enter for
102 	 * this ordered extent so that we do not expose stale data.
103 	 */
104 	u64 truncated_len;
105 
106 	/* flags (described above) */
107 	unsigned long flags;
108 
109 	/* compression algorithm */
110 	int compress_type;
111 
112 	/* reference count */
113 	atomic_t refs;
114 
115 	/* the inode we belong to */
116 	struct inode *inode;
117 
118 	/* list of checksums for insertion when the extent io is done */
119 	struct list_head list;
120 
121 	/* If we need to wait on this to be done */
122 	struct list_head log_list;
123 
124 	/* used to wait for the BTRFS_ORDERED_COMPLETE bit */
125 	wait_queue_head_t wait;
126 
127 	/* our friendly rbtree entry */
128 	struct rb_node rb_node;
129 
130 	/* a per root list of all the pending ordered extents */
131 	struct list_head root_extent_list;
132 
133 	struct btrfs_work work;
134 
135 	struct completion completion;
136 	struct btrfs_work flush_work;
137 	struct list_head work_list;
138 };
139 
140 /*
141  * calculates the total size you need to allocate for an ordered sum
142  * structure spanning 'bytes' in the file
143  */
144 static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
145 					 unsigned long bytes)
146 {
147 	int num_sectors = (int)DIV_ROUND_UP(bytes, root->sectorsize);
148 	return sizeof(struct btrfs_ordered_sum) + num_sectors * sizeof(u32);
149 }
150 
151 static inline void
152 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
153 {
154 	spin_lock_init(&t->lock);
155 	t->tree = RB_ROOT;
156 	t->last = NULL;
157 }
158 
159 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
160 void btrfs_remove_ordered_extent(struct inode *inode,
161 				struct btrfs_ordered_extent *entry);
162 int btrfs_dec_test_ordered_pending(struct inode *inode,
163 				   struct btrfs_ordered_extent **cached,
164 				   u64 file_offset, u64 io_size, int uptodate);
165 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
166 				   struct btrfs_ordered_extent **cached,
167 				   u64 *file_offset, u64 io_size,
168 				   int uptodate);
169 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
170 			     u64 start, u64 len, u64 disk_len, int type);
171 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
172 				 u64 start, u64 len, u64 disk_len, int type);
173 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
174 				      u64 start, u64 len, u64 disk_len,
175 				      int type, int compress_type);
176 void btrfs_add_ordered_sum(struct inode *inode,
177 			   struct btrfs_ordered_extent *entry,
178 			   struct btrfs_ordered_sum *sum);
179 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
180 							 u64 file_offset);
181 void btrfs_start_ordered_extent(struct inode *inode,
182 				struct btrfs_ordered_extent *entry, int wait);
183 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
184 struct btrfs_ordered_extent *
185 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
186 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
187 							u64 file_offset,
188 							u64 len);
189 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
190 				struct btrfs_ordered_extent *ordered);
191 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
192 			   u32 *sum, int len);
193 int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr);
194 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr);
195 void btrfs_get_logged_extents(struct inode *inode,
196 			      struct list_head *logged_list);
197 void btrfs_put_logged_extents(struct list_head *logged_list);
198 void btrfs_submit_logged_extents(struct list_head *logged_list,
199 				 struct btrfs_root *log);
200 void btrfs_wait_logged_extents(struct btrfs_root *log, u64 transid);
201 void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid);
202 int __init ordered_data_init(void);
203 void ordered_data_exit(void);
204 #endif
205