--- /dev/null
+/*
+ * linux/fs/hpfs/file.c
+ *
+ * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ * file VFS functions
+ */
+
+#include "hpfs_fn.h"
+#include <linux/mpage.h>
+
+#define BLOCKS(size) (((size) + 511) >> 9)
+
+static int hpfs_file_release(struct inode *inode, struct file *file)
+{
+ hpfs_lock(inode->i_sb);
+ hpfs_write_if_changed(inode);
+ hpfs_unlock(inode->i_sb);
+ return 0;
+}
+
+int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+ struct inode *inode = file->f_mapping->host;
+ int ret;
+
+ ret = filemap_write_and_wait_range(file->f_mapping, start, end);
+ if (ret)
+ return ret;
+ return sync_blockdev(inode->i_sb->s_bdev);
+}
+
+/*
+ * generic_file_read often calls bmap with non-existing sector,
+ * so we must ignore such errors.
+ */
+
+static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs)
+{
+ struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
+ unsigned n, disk_secno;
+ struct fnode *fnode;
+ struct buffer_head *bh;
+ if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
+ n = file_secno - hpfs_inode->i_file_sec;
+ if (n < hpfs_inode->i_n_secs) {
+ *n_secs = hpfs_inode->i_n_secs - n;
+ return hpfs_inode->i_disk_sec + n;
+ }
+ if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
+ disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
+ if (disk_secno == -1) return 0;
+ if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
+ n = file_secno - hpfs_inode->i_file_sec;
+ if (n < hpfs_inode->i_n_secs) {
+ *n_secs = hpfs_inode->i_n_secs - n;
+ return hpfs_inode->i_disk_sec + n;
+ }
+ *n_secs = 1;
+ return disk_secno;
+}
+
+void hpfs_truncate(struct inode *i)
+{
+ if (IS_IMMUTABLE(i)) return /*-EPERM*/;
+ hpfs_lock_assert(i->i_sb);
+
+ hpfs_i(i)->i_n_secs = 0;
+ i->i_blocks = 1 + ((i->i_size + 511) >> 9);
+ hpfs_i(i)->mmu_private = i->i_size;
+ hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
+ hpfs_write_inode(i);
+ hpfs_i(i)->i_n_secs = 0;
+}
+
+static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
+{
+ int r;
+ secno s;
+ unsigned n_secs;
+ hpfs_lock(inode->i_sb);
+ s = hpfs_bmap(inode, iblock, &n_secs);
+ if (s) {
+ if (bh_result->b_size >> 9 < n_secs)
+ n_secs = bh_result->b_size >> 9;
+ map_bh(bh_result, inode->i_sb, s);
+ bh_result->b_size = n_secs << 9;
+ goto ret_0;
+ }
+ if (!create) goto ret_0;
+ if (iblock<<9 != hpfs_i(inode)->mmu_private) {
+ BUG();
+ r = -EIO;
+ goto ret_r;
+ }
+ if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
+ hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
+ r = -ENOSPC;
+ goto ret_r;
+ }
+ inode->i_blocks++;
+ hpfs_i(inode)->mmu_private += 512;
+ set_buffer_new(bh_result);
+ map_bh(bh_result, inode->i_sb, s);
+ ret_0:
+ r = 0;
+ ret_r:
+ hpfs_unlock(inode->i_sb);
+ return r;
+}
+
+static int hpfs_readpage(struct file *file, struct page *page)
+{
+ return mpage_readpage(page, hpfs_get_block);
+}
+
+static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ return block_write_full_page(page, hpfs_get_block, wbc);
+}
+
+static int hpfs_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ return mpage_readpages(mapping, pages, nr_pages, hpfs_get_block);
+}
+
+static int hpfs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ return mpage_writepages(mapping, wbc, hpfs_get_block);
+}
+
+static void hpfs_write_failed(struct address_space *mapping, loff_t to)
+{
+ struct inode *inode = mapping->host;
+
+ hpfs_lock(inode->i_sb);
+
+ if (to > inode->i_size) {
+ truncate_pagecache(inode, inode->i_size);
+ hpfs_truncate(inode);
+ }
+
+ hpfs_unlock(inode->i_sb);
+}
+
+static int hpfs_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int ret;
+
+ *pagep = NULL;
+ ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+ hpfs_get_block,
+ &hpfs_i(mapping->host)->mmu_private);
+ if (unlikely(ret))
+ hpfs_write_failed(mapping, pos + len);
+
+ return ret;
+}
+
+static int hpfs_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *pagep, void *fsdata)
+{
+ struct inode *inode = mapping->host;
+ int err;
+ err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
+ if (err < len)
+ hpfs_write_failed(mapping, pos + len);
+ if (!(err < 0)) {
+ /* make sure we write it on close, if not earlier */
+ hpfs_lock(inode->i_sb);
+ hpfs_i(inode)->i_dirty = 1;
+ hpfs_unlock(inode->i_sb);
+ }
+ return err;
+}
+
+static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
+{
+ return generic_block_bmap(mapping,block,hpfs_get_block);
+}
+
+const struct address_space_operations hpfs_aops = {
+ .readpage = hpfs_readpage,
+ .writepage = hpfs_writepage,
+ .readpages = hpfs_readpages,
+ .writepages = hpfs_writepages,
+ .write_begin = hpfs_write_begin,
+ .write_end = hpfs_write_end,
+ .bmap = _hpfs_bmap
+};
+
+const struct file_operations hpfs_file_ops =
+{
+ .llseek = generic_file_llseek,
+ .read_iter = generic_file_read_iter,
+ .write_iter = generic_file_write_iter,
+ .mmap = generic_file_mmap,
+ .release = hpfs_file_release,
+ .fsync = hpfs_file_fsync,
+ .splice_read = generic_file_splice_read,
+};
+
+const struct inode_operations hpfs_file_iops =
+{
+ .setattr = hpfs_setattr,
+};
Code Review / kvmfornfv.git / blobdiff