Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
[linux-2.6.git] / fs / hpfs / file.c
1 /*
2  *  linux/fs/hpfs/file.c
3  *
4  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
5  *
6  *  file VFS functions
7  */
8
9 #include "hpfs_fn.h"
10
11 #define BLOCKS(size) (((size) + 511) >> 9)
12
13 static int hpfs_file_release(struct inode *inode, struct file *file)
14 {
15         hpfs_lock(inode->i_sb);
16         hpfs_write_if_changed(inode);
17         hpfs_unlock(inode->i_sb);
18         return 0;
19 }
20
21 int hpfs_file_fsync(struct file *file, int datasync)
22 {
23         /*return file_fsync(file, datasync);*/
24         return 0; /* Don't fsync :-) */
25 }
26
27 /*
28  * generic_file_read often calls bmap with non-existing sector,
29  * so we must ignore such errors.
30  */
31
32 static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
33 {
34         struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
35         unsigned n, disk_secno;
36         struct fnode *fnode;
37         struct buffer_head *bh;
38         if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
39         n = file_secno - hpfs_inode->i_file_sec;
40         if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n;
41         if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
42         disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
43         if (disk_secno == -1) return 0;
44         if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
45         return disk_secno;
46 }
47
48 static void hpfs_truncate(struct inode *i)
49 {
50         if (IS_IMMUTABLE(i)) return /*-EPERM*/;
51         hpfs_lock(i->i_sb);
52         hpfs_i(i)->i_n_secs = 0;
53         i->i_blocks = 1 + ((i->i_size + 511) >> 9);
54         hpfs_i(i)->mmu_private = i->i_size;
55         hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
56         hpfs_write_inode(i);
57         hpfs_i(i)->i_n_secs = 0;
58         hpfs_unlock(i->i_sb);
59 }
60
61 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
62 {
63         secno s;
64         s = hpfs_bmap(inode, iblock);
65         if (s) {
66                 map_bh(bh_result, inode->i_sb, s);
67                 return 0;
68         }
69         if (!create) return 0;
70         if (iblock<<9 != hpfs_i(inode)->mmu_private) {
71                 BUG();
72                 return -EIO;
73         }
74         if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
75                 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
76                 return -ENOSPC;
77         }
78         inode->i_blocks++;
79         hpfs_i(inode)->mmu_private += 512;
80         set_buffer_new(bh_result);
81         map_bh(bh_result, inode->i_sb, s);
82         return 0;
83 }
84
85 static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
86 {
87         return block_write_full_page(page,hpfs_get_block, wbc);
88 }
89
90 static int hpfs_readpage(struct file *file, struct page *page)
91 {
92         return block_read_full_page(page,hpfs_get_block);
93 }
94
95 static int hpfs_write_begin(struct file *file, struct address_space *mapping,
96                         loff_t pos, unsigned len, unsigned flags,
97                         struct page **pagep, void **fsdata)
98 {
99         int ret;
100
101         *pagep = NULL;
102         ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
103                                 hpfs_get_block,
104                                 &hpfs_i(mapping->host)->mmu_private);
105         if (unlikely(ret)) {
106                 loff_t isize = mapping->host->i_size;
107                 if (pos + len > isize)
108                         vmtruncate(mapping->host, isize);
109         }
110
111         return ret;
112 }
113
114 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
115 {
116         return generic_block_bmap(mapping,block,hpfs_get_block);
117 }
118
119 const struct address_space_operations hpfs_aops = {
120         .readpage = hpfs_readpage,
121         .writepage = hpfs_writepage,
122         .write_begin = hpfs_write_begin,
123         .write_end = generic_write_end,
124         .bmap = _hpfs_bmap
125 };
126
127 static ssize_t hpfs_file_write(struct file *file, const char __user *buf,
128                         size_t count, loff_t *ppos)
129 {
130         ssize_t retval;
131
132         retval = do_sync_write(file, buf, count, ppos);
133         if (retval > 0)
134                 hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1;
135         return retval;
136 }
137
138 const struct file_operations hpfs_file_ops =
139 {
140         .llseek         = generic_file_llseek,
141         .read           = do_sync_read,
142         .aio_read       = generic_file_aio_read,
143         .write          = hpfs_file_write,
144         .aio_write      = generic_file_aio_write,
145         .mmap           = generic_file_mmap,
146         .release        = hpfs_file_release,
147         .fsync          = hpfs_file_fsync,
148         .splice_read    = generic_file_splice_read,
149 };
150
151 const struct inode_operations hpfs_file_iops =
152 {
153         .truncate       = hpfs_truncate,
154         .setattr        = hpfs_setattr,
155 };