diff options
Diffstat (limited to 'fs/hpfs/file.c')
| -rw-r--r-- | fs/hpfs/file.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c new file mode 100644 index 000000000..6d8cfe9b5 --- /dev/null +++ b/fs/hpfs/file.c @@ -0,0 +1,211 @@ +/* + * 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, +}; |