From 05eb0b51fb46430050d5873458612f53e0234f2e Mon Sep 17 00:00:00 2001 From: OGAWA Hirofumi Date: Sun, 8 Jan 2006 01:02:13 -0800 Subject: [PATCH] fat: support a truncate() for expanding size (generic_cont_expand) This patch changes generic_cont_expand(), in order to share the code with fatfs. - Use vmtruncate() if ->prepare_write() returns a error. Even if ->prepare_write() returns an error, it may already have added some blocks. So, this truncates blocks outside of ->i_size by vmtruncate(). - Add generic_cont_expand_simple(). The generic_cont_expand_simple() assumes that ->prepare_write() can handle the block boundary. With this, we don't need to care the extra byte. And for expanding a file size by truncate(), fatfs uses the added generic_cont_expand_simple(). Signed-off-by: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fat/file.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) (limited to 'fs/fat') diff --git a/fs/fat/file.c b/fs/fat/file.c index 15229fe569c3..9b07c328a6fc 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -11,6 +11,7 @@ #include #include #include +#include int fat_generic_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) @@ -124,6 +125,24 @@ struct file_operations fat_file_operations = { .sendfile = generic_file_sendfile, }; +static int fat_cont_expand(struct inode *inode, loff_t size) +{ + struct address_space *mapping = inode->i_mapping; + loff_t start = inode->i_size, count = size - inode->i_size; + int err; + + err = generic_cont_expand_simple(inode, size); + if (err) + goto out; + + inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; + mark_inode_dirty(inode); + if (IS_SYNC(inode)) + err = sync_page_range_nolock(inode, mapping, start, count); +out: + return err; +} + int fat_notify_change(struct dentry *dentry, struct iattr *attr) { struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb); @@ -132,11 +151,17 @@ int fat_notify_change(struct dentry *dentry, struct iattr *attr) lock_kernel(); - /* FAT cannot truncate to a longer file */ + /* + * Expand the file. Since inode_setattr() updates ->i_size + * before calling the ->truncate(), but FAT needs to fill the + * hole before it. + */ if (attr->ia_valid & ATTR_SIZE) { if (attr->ia_size > inode->i_size) { - error = -EPERM; - goto out; + error = fat_cont_expand(inode, attr->ia_size); + if (error || attr->ia_valid == ATTR_SIZE) + goto out; + attr->ia_valid &= ~ATTR_SIZE; } } -- cgit v1.2.3