From 53a2731f9310a66beaf55677229ab067c85ce4fa Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Wed, 23 May 2007 13:58:15 -0700 Subject: eCryptfs: delay writing 0's after llseek until write Delay writing 0's out in eCryptfs after a seek past the end of the file until data is actually written. http://www.opengroup.org/onlinepubs/009695399/functions/lseek.html ``The lseek() function shall not, by itself, extend the size of a file.'' Without this fix, applications that lseek() past the end of the file without writing will experience unexpected behavior. Signed-off-by: Michael Halcrow Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/file.c | 59 +----------------------------------------------------- 1 file changed, 1 insertion(+), 58 deletions(-) (limited to 'fs/ecryptfs/file.c') diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 9881b5c5de5..59288d81707 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -32,63 +32,6 @@ #include #include "ecryptfs_kernel.h" -/** - * ecryptfs_llseek - * @file: File we are seeking in - * @offset: The offset to seek to - * @origin: 2 - offset from i_size; 1 - offset from f_pos - * - * Returns the position we have seeked to, or negative on error - */ -static loff_t ecryptfs_llseek(struct file *file, loff_t offset, int origin) -{ - loff_t rv; - loff_t new_end_pos; - int rc; - int expanding_file = 0; - struct inode *inode = file->f_mapping->host; - - /* If our offset is past the end of our file, we're going to - * need to grow it so we have a valid length of 0's */ - new_end_pos = offset; - switch (origin) { - case 2: - new_end_pos += i_size_read(inode); - expanding_file = 1; - break; - case 1: - new_end_pos += file->f_pos; - if (new_end_pos > i_size_read(inode)) { - ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) " - "> i_size_read(inode)(=[0x%.16x])\n", - new_end_pos, i_size_read(inode)); - expanding_file = 1; - } - break; - default: - if (new_end_pos > i_size_read(inode)) { - ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) " - "> i_size_read(inode)(=[0x%.16x])\n", - new_end_pos, i_size_read(inode)); - expanding_file = 1; - } - } - ecryptfs_printk(KERN_DEBUG, "new_end_pos = [0x%.16x]\n", new_end_pos); - if (expanding_file) { - rc = ecryptfs_truncate(file->f_path.dentry, new_end_pos); - if (rc) { - rv = rc; - ecryptfs_printk(KERN_ERR, "Error on attempt to " - "truncate to (higher) offset [0x%.16x];" - " rc = [%d]\n", new_end_pos, rc); - goto out; - } - } - rv = generic_file_llseek(file, offset, origin); -out: - return rv; -} - /** * ecryptfs_read_update_atime * @@ -425,7 +368,7 @@ const struct file_operations ecryptfs_dir_fops = { }; const struct file_operations ecryptfs_main_fops = { - .llseek = ecryptfs_llseek, + .llseek = generic_file_llseek, .read = do_sync_read, .aio_read = ecryptfs_read_update_atime, .write = do_sync_write, -- cgit v1.2.3-18-g5258