ext4: avoid hangs in ext4_da_should_update_i_disksize()
[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, loff_t start, loff_t end, int datasync)
22 {
23         struct inode *inode = file->f_mapping->host;
24         int ret;
25
26         ret = filemap_write_and_wait_range(file->f_mapping, start, end);
27         if (ret)
28                 return ret;
29         return sync_blockdev(inode->i_sb->s_bdev);
30 }
31
32 /*
33  * generic_file_read often calls bmap with non-existing sector,
34  * so we must ignore such errors.
35  */
36
37 static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
38 {
39         struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
40         unsigned n, disk_secno;
41         struct fnode *fnode;
42         struct buffer_head *bh;
43         if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
44         n = file_secno - hpfs_inode->i_file_sec;
45         if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n;
46         if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
47         disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
48         if (disk_secno == -1) return 0;
49         if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
50         return disk_secno;
51 }
52
53 static void hpfs_truncate(struct inode *i)
54 {
55         if (IS_IMMUTABLE(i)) return /*-EPERM*/;
56         hpfs_lock_assert(i->i_sb);
57
58         hpfs_i(i)->i_n_secs = 0;
59         i->i_blocks = 1 + ((i->i_size + 511) >> 9);
60         hpfs_i(i)->mmu_private = i->i_size;
61         hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
62         hpfs_write_inode(i);
63         hpfs_i(i)->i_n_secs = 0;
64 }
65
66 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
67 {
68         int r;
69         secno s;
70         hpfs_lock(inode->i_sb);
71         s = hpfs_bmap(inode, iblock);
72         if (s) {
73                 map_bh(bh_result, inode->i_sb, s);
74                 goto ret_0;
75         }
76         if (!create) goto ret_0;
77         if (iblock<<9 != hpfs_i(inode)->mmu_private) {
78                 BUG();
79                 r = -EIO;
80                 goto ret_r;
81         }
82         if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
83                 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
84                 r = -ENOSPC;
85                 goto ret_r;
86         }
87         inode->i_blocks++;
88         hpfs_i(inode)->mmu_private += 512;
89         set_buffer_new(bh_result);
90         map_bh(bh_result, inode->i_sb, s);
91         ret_0:
92         r = 0;
93         ret_r:
94         hpfs_unlock(inode->i_sb);
95         return r;
96 }
97
98 static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
99 {
100         return block_write_full_page(page,hpfs_get_block, wbc);
101 }
102
103 static int hpfs_readpage(struct file *file, struct page *page)
104 {
105         return block_read_full_page(page,hpfs_get_block);
106 }
107
108 static int hpfs_write_begin(struct file *file, struct address_space *mapping,
109                         loff_t pos, unsigned len, unsigned flags,
110                         struct page **pagep, void **fsdata)
111 {
112         int ret;
113
114         *pagep = NULL;
115         ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
116                                 hpfs_get_block,
117                                 &hpfs_i(mapping->host)->mmu_private);
118         if (unlikely(ret)) {
119                 loff_t isize = mapping->host->i_size;
120                 if (pos + len > isize)
121                         vmtruncate(mapping->host, isize);
122         }
123
124         return ret;
125 }
126
127 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
128 {
129         return generic_block_bmap(mapping,block,hpfs_get_block);
130 }
131
132 const struct address_space_operations hpfs_aops = {
133         .readpage = hpfs_readpage,
134         .writepage = hpfs_writepage,
135         .write_begin = hpfs_write_begin,
136         .write_end = generic_write_end,
137         .bmap = _hpfs_bmap
138 };
139
140 static ssize_t hpfs_file_write(struct file *file, const char __user *buf,
141                         size_t count, loff_t *ppos)
142 {
143         ssize_t retval;
144
145         retval = do_sync_write(file, buf, count, ppos);
146         if (retval > 0) {
147                 hpfs_lock(file->f_path.dentry->d_sb);
148                 hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1;
149                 hpfs_unlock(file->f_path.dentry->d_sb);
150         }
151         return retval;
152 }
153
154 const struct file_operations hpfs_file_ops =
155 {
156         .llseek         = generic_file_llseek,
157         .read           = do_sync_read,
158         .aio_read       = generic_file_aio_read,
159         .write          = hpfs_file_write,
160         .aio_write      = generic_file_aio_write,
161         .mmap           = generic_file_mmap,
162         .release        = hpfs_file_release,
163         .fsync          = hpfs_file_fsync,
164         .splice_read    = generic_file_splice_read,
165 };
166
167 const struct inode_operations hpfs_file_iops =
168 {
169         .truncate       = hpfs_truncate,
170         .setattr        = hpfs_setattr,
171 };