Root/fs/btrfs/ordered-data.h

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 */
23struct btrfs_ordered_inode_tree {
24    spinlock_t lock;
25    struct rb_root tree;
26    struct rb_node *last;
27};
28
29/*
30 * these are used to collect checksums done just before bios submission.
31 * They are attached via a list into the ordered extent, and
32 * checksum items are inserted into the tree after all the blocks in
33 * the ordered extent are on disk
34 */
35struct btrfs_sector_sum {
36    /* bytenr on disk */
37    u64 bytenr;
38    u32 sum;
39};
40
41struct btrfs_ordered_sum {
42    /* bytenr is the start of this extent on disk */
43    u64 bytenr;
44
45    /*
46     * this is the length in bytes covered by the sums array below.
47     */
48    unsigned long len;
49    struct list_head list;
50    /* last field is a variable length array of btrfs_sector_sums */
51    struct btrfs_sector_sum sums[];
52};
53
54/*
55 * bits for the flags field:
56 *
57 * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
58 * It is used to make sure metadata is inserted into the tree only once
59 * per extent.
60 *
61 * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
62 * rbtree, just before waking any waiters. It is used to indicate the
63 * IO is done and any metadata is inserted into the tree.
64 */
65#define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */
66
67#define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */
68
69#define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */
70
71#define BTRFS_ORDERED_COMPRESSED 3 /* writing a compressed extent */
72
73#define BTRFS_ORDERED_PREALLOC 4 /* set when writing to prealloced extent */
74
75struct btrfs_ordered_extent {
76    /* logical offset in the file */
77    u64 file_offset;
78
79    /* disk byte number */
80    u64 start;
81
82    /* ram length of the extent in bytes */
83    u64 len;
84
85    /* extent length on disk */
86    u64 disk_len;
87
88    /* number of bytes that still need writing */
89    u64 bytes_left;
90
91    /* flags (described above) */
92    unsigned long flags;
93
94    /* reference count */
95    atomic_t refs;
96
97    /* the inode we belong to */
98    struct inode *inode;
99
100    /* list of checksums for insertion when the extent io is done */
101    struct list_head list;
102
103    /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
104    wait_queue_head_t wait;
105
106    /* our friendly rbtree entry */
107    struct rb_node rb_node;
108
109    /* a per root list of all the pending ordered extents */
110    struct list_head root_extent_list;
111};
112
113
114/*
115 * calculates the total size you need to allocate for an ordered sum
116 * structure spanning 'bytes' in the file
117 */
118static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
119                     unsigned long bytes)
120{
121    unsigned long num_sectors = (bytes + root->sectorsize - 1) /
122        root->sectorsize;
123    num_sectors++;
124    return sizeof(struct btrfs_ordered_sum) +
125        num_sectors * sizeof(struct btrfs_sector_sum);
126}
127
128static inline void
129btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
130{
131    spin_lock_init(&t->lock);
132    t->tree = RB_ROOT;
133    t->last = NULL;
134}
135
136int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
137int btrfs_remove_ordered_extent(struct inode *inode,
138                struct btrfs_ordered_extent *entry);
139int btrfs_dec_test_ordered_pending(struct inode *inode,
140                   struct btrfs_ordered_extent **cached,
141                   u64 file_offset, u64 io_size);
142int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
143                 u64 start, u64 len, u64 disk_len, int tyep);
144int btrfs_add_ordered_sum(struct inode *inode,
145              struct btrfs_ordered_extent *entry,
146              struct btrfs_ordered_sum *sum);
147struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
148                             u64 file_offset);
149void btrfs_start_ordered_extent(struct inode *inode,
150                struct btrfs_ordered_extent *entry, int wait);
151int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
152struct btrfs_ordered_extent *
153btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
154int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
155                struct btrfs_ordered_extent *ordered);
156int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
157int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
158int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
159                struct btrfs_root *root,
160                struct inode *inode);
161int btrfs_wait_ordered_extents(struct btrfs_root *root,
162                   int nocow_only, int delay_iput);
163#endif
164

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