4 * Written 1992,1993 by Werner Almesberger
6 * regular file handling primitives for fat-based filesystems
9 #include <linux/time.h>
10 #include <linux/msdos_fs.h>
11 #include <linux/smp_lock.h>
12 #include <linux/buffer_head.h>
14 static ssize_t fat_file_write(struct file *filp, const char __user *buf,
15 size_t count, loff_t *ppos);
17 struct file_operations fat_file_operations = {
18 .llseek = generic_file_llseek,
19 .read = generic_file_read,
20 .write = fat_file_write,
21 .mmap = generic_file_mmap,
23 .readv = generic_file_readv,
24 .writev = generic_file_writev,
25 .sendfile = generic_file_sendfile,
28 struct inode_operations fat_file_inode_operations = {
29 .truncate = fat_truncate,
30 .setattr = fat_notify_change,
33 int fat_get_block(struct inode *inode, sector_t iblock,
34 struct buffer_head *bh_result, int create)
36 struct super_block *sb = inode->i_sb;
40 err = fat_bmap(inode, iblock, &phys);
44 map_bh(bh_result, sb, phys);
49 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
53 if (!((unsigned long)iblock & (MSDOS_SB(sb)->sec_per_clus - 1))) {
56 error = fat_add_cluster(inode);
60 MSDOS_I(inode)->mmu_private += sb->s_blocksize;
61 err = fat_bmap(inode, iblock, &phys);
66 set_buffer_new(bh_result);
67 map_bh(bh_result, sb, phys);
71 static ssize_t fat_file_write(struct file *filp, const char __user *buf,
72 size_t count, loff_t *ppos)
74 struct inode *inode = filp->f_dentry->d_inode;
77 retval = generic_file_write(filp, buf, count, ppos);
79 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
80 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
81 mark_inode_dirty(inode);
86 void fat_truncate(struct inode *inode)
88 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
89 const unsigned int cluster_size = sbi->cluster_size;
92 /* Why no return value? Surely the disk could fail... */
93 if (IS_RDONLY (inode))
95 if (IS_IMMUTABLE(inode))
99 * This protects against truncating a file bigger than it was then
100 * trying to write into the hole.
102 if (MSDOS_I(inode)->mmu_private > inode->i_size)
103 MSDOS_I(inode)->mmu_private = inode->i_size;
105 nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits;
108 fat_free(inode, nr_clusters);
109 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
111 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
112 mark_inode_dirty(inode);