xref: /linux/fs/btrfs/btrfs_inode.h (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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_I__
20 #define __BTRFS_I__
21 
22 #include <linux/hash.h>
23 #include "extent_map.h"
24 #include "extent_io.h"
25 #include "ordered-data.h"
26 #include "delayed-inode.h"
27 
28 /*
29  * ordered_data_close is set by truncate when a file that used
30  * to have good data has been truncated to zero.  When it is set
31  * the btrfs file release call will add this inode to the
32  * ordered operations list so that we make sure to flush out any
33  * new data the application may have written before commit.
34  */
35 #define BTRFS_INODE_ORDERED_DATA_CLOSE		0
36 #define BTRFS_INODE_ORPHAN_META_RESERVED	1
37 #define BTRFS_INODE_DUMMY			2
38 #define BTRFS_INODE_IN_DEFRAG			3
39 #define BTRFS_INODE_DELALLOC_META_RESERVED	4
40 #define BTRFS_INODE_HAS_ORPHAN_ITEM		5
41 #define BTRFS_INODE_HAS_ASYNC_EXTENT		6
42 #define BTRFS_INODE_NEEDS_FULL_SYNC		7
43 #define BTRFS_INODE_COPY_EVERYTHING		8
44 #define BTRFS_INODE_IN_DELALLOC_LIST		9
45 #define BTRFS_INODE_READDIO_NEED_LOCK		10
46 
47 /* in memory btrfs inode */
48 struct btrfs_inode {
49 	/* which subvolume this inode belongs to */
50 	struct btrfs_root *root;
51 
52 	/* key used to find this inode on disk.  This is used by the code
53 	 * to read in roots of subvolumes
54 	 */
55 	struct btrfs_key location;
56 
57 	/* Lock for counters */
58 	spinlock_t lock;
59 
60 	/* the extent_tree has caches of all the extent mappings to disk */
61 	struct extent_map_tree extent_tree;
62 
63 	/* the io_tree does range state (DIRTY, LOCKED etc) */
64 	struct extent_io_tree io_tree;
65 
66 	/* special utility tree used to record which mirrors have already been
67 	 * tried when checksums fail for a given block
68 	 */
69 	struct extent_io_tree io_failure_tree;
70 
71 	/* held while logging the inode in tree-log.c */
72 	struct mutex log_mutex;
73 
74 	/* held while doing delalloc reservations */
75 	struct mutex delalloc_mutex;
76 
77 	/* used to order data wrt metadata */
78 	struct btrfs_ordered_inode_tree ordered_tree;
79 
80 	/* list of all the delalloc inodes in the FS.  There are times we need
81 	 * to write all the delalloc pages to disk, and this list is used
82 	 * to walk them all.
83 	 */
84 	struct list_head delalloc_inodes;
85 
86 	/*
87 	 * list for tracking inodes that must be sent to disk before a
88 	 * rename or truncate commit
89 	 */
90 	struct list_head ordered_operations;
91 
92 	/* node for the red-black tree that links inodes in subvolume root */
93 	struct rb_node rb_node;
94 
95 	unsigned long runtime_flags;
96 
97 	/* Keep track of who's O_SYNC/fsyncing currently */
98 	atomic_t sync_writers;
99 
100 	/* full 64 bit generation number, struct vfs_inode doesn't have a big
101 	 * enough field for this.
102 	 */
103 	u64 generation;
104 
105 	/*
106 	 * transid of the trans_handle that last modified this inode
107 	 */
108 	u64 last_trans;
109 
110 	/*
111 	 * log transid when this inode was last modified
112 	 */
113 	u64 last_sub_trans;
114 
115 	/*
116 	 * transid that last logged this inode
117 	 */
118 	u64 logged_trans;
119 
120 	/* total number of bytes pending delalloc, used by stat to calc the
121 	 * real block usage of the file
122 	 */
123 	u64 delalloc_bytes;
124 
125 	/*
126 	 * the size of the file stored in the metadata on disk.  data=ordered
127 	 * means the in-memory i_size might be larger than the size on disk
128 	 * because not all the blocks are written yet.
129 	 */
130 	u64 disk_i_size;
131 
132 	/*
133 	 * if this is a directory then index_cnt is the counter for the index
134 	 * number for new files that are created
135 	 */
136 	u64 index_cnt;
137 
138 	/* the fsync log has some corner cases that mean we have to check
139 	 * directories to see if any unlinks have been done before
140 	 * the directory was logged.  See tree-log.c for all the
141 	 * details
142 	 */
143 	u64 last_unlink_trans;
144 
145 	/*
146 	 * Number of bytes outstanding that are going to need csums.  This is
147 	 * used in ENOSPC accounting.
148 	 */
149 	u64 csum_bytes;
150 
151 	/* flags field from the on disk inode */
152 	u32 flags;
153 
154 	/* a local copy of root's last_log_commit */
155 	unsigned long last_log_commit;
156 
157 	/*
158 	 * Counters to keep track of the number of extent item's we may use due
159 	 * to delalloc and such.  outstanding_extents is the number of extent
160 	 * items we think we'll end up using, and reserved_extents is the number
161 	 * of extent items we've reserved metadata for.
162 	 */
163 	unsigned outstanding_extents;
164 	unsigned reserved_extents;
165 
166 	/*
167 	 * always compress this one file
168 	 */
169 	unsigned force_compress;
170 
171 	struct btrfs_delayed_node *delayed_node;
172 
173 	struct inode vfs_inode;
174 };
175 
176 extern unsigned char btrfs_filetype_table[];
177 
178 static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
179 {
180 	return container_of(inode, struct btrfs_inode, vfs_inode);
181 }
182 
183 static inline unsigned long btrfs_inode_hash(u64 objectid,
184 					     const struct btrfs_root *root)
185 {
186 	u64 h = objectid ^ (root->objectid * GOLDEN_RATIO_PRIME);
187 
188 #if BITS_PER_LONG == 32
189 	h = (h >> 32) ^ (h & 0xffffffff);
190 #endif
191 
192 	return (unsigned long)h;
193 }
194 
195 static inline void btrfs_insert_inode_hash(struct inode *inode)
196 {
197 	unsigned long h = btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root);
198 
199 	__insert_inode_hash(inode, h);
200 }
201 
202 static inline u64 btrfs_ino(struct inode *inode)
203 {
204 	u64 ino = BTRFS_I(inode)->location.objectid;
205 
206 	/*
207 	 * !ino: btree_inode
208 	 * type == BTRFS_ROOT_ITEM_KEY: subvol dir
209 	 */
210 	if (!ino || BTRFS_I(inode)->location.type == BTRFS_ROOT_ITEM_KEY)
211 		ino = inode->i_ino;
212 	return ino;
213 }
214 
215 static inline void btrfs_i_size_write(struct inode *inode, u64 size)
216 {
217 	i_size_write(inode, size);
218 	BTRFS_I(inode)->disk_i_size = size;
219 }
220 
221 static inline bool btrfs_is_free_space_inode(struct inode *inode)
222 {
223 	struct btrfs_root *root = BTRFS_I(inode)->root;
224 
225 	if (root == root->fs_info->tree_root &&
226 	    btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)
227 		return true;
228 	if (BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID)
229 		return true;
230 	return false;
231 }
232 
233 static inline int btrfs_inode_in_log(struct inode *inode, u64 generation)
234 {
235 	if (BTRFS_I(inode)->logged_trans == generation &&
236 	    BTRFS_I(inode)->last_sub_trans <=
237 	    BTRFS_I(inode)->last_log_commit &&
238 	    BTRFS_I(inode)->last_sub_trans <=
239 	    BTRFS_I(inode)->root->last_log_commit)
240 		return 1;
241 	return 0;
242 }
243 
244 struct btrfs_dio_private {
245 	struct inode *inode;
246 	u64 logical_offset;
247 	u64 disk_bytenr;
248 	u64 bytes;
249 	void *private;
250 
251 	/* number of bios pending for this dio */
252 	atomic_t pending_bios;
253 
254 	/* IO errors */
255 	int errors;
256 
257 	/* orig_bio is our btrfs_io_bio */
258 	struct bio *orig_bio;
259 
260 	/* dio_bio came from fs/direct-io.c */
261 	struct bio *dio_bio;
262 	u8 csum[0];
263 };
264 
265 /*
266  * Disable DIO read nolock optimization, so new dio readers will be forced
267  * to grab i_mutex. It is used to avoid the endless truncate due to
268  * nonlocked dio read.
269  */
270 static inline void btrfs_inode_block_unlocked_dio(struct inode *inode)
271 {
272 	set_bit(BTRFS_INODE_READDIO_NEED_LOCK, &BTRFS_I(inode)->runtime_flags);
273 	smp_mb();
274 }
275 
276 static inline void btrfs_inode_resume_unlocked_dio(struct inode *inode)
277 {
278 	smp_mb__before_clear_bit();
279 	clear_bit(BTRFS_INODE_READDIO_NEED_LOCK,
280 		  &BTRFS_I(inode)->runtime_flags);
281 }
282 
283 #endif
284