From 1bf9d14dff4a2c4de6152c6f751bdaf6896b68bb Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 16 Jun 2013 20:27:42 +0400 Subject: [PATCH] new helper: fixed_size_llseek() Signed-off-by: Al Viro --- fs/read_write.c | 20 ++++++++++++++++++++ include/linux/fs.h | 2 ++ 2 files changed, 22 insertions(+) diff --git a/fs/read_write.c b/fs/read_write.c index f646c8b565b9..782dfc3acebc 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -144,6 +144,26 @@ loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) } EXPORT_SYMBOL(generic_file_llseek); +/** + * fixed_size_llseek - llseek implementation for fixed-sized devices + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * @size: size of the file + * + */ +loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) +{ + switch (whence) { + case SEEK_SET: case SEEK_CUR: case SEEK_END: + return generic_file_llseek_size(file, offset, whence, + size, size); + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(fixed_size_llseek); + /** * noop_llseek - No Operation Performed llseek implementation * @file: file structure to seek on diff --git a/include/linux/fs.h b/include/linux/fs.h index 1db01c13ddce..803b7fa2520a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2428,6 +2428,8 @@ extern loff_t no_llseek(struct file *file, loff_t offset, int whence); extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence); extern loff_t generic_file_llseek_size(struct file *file, loff_t offset, int whence, loff_t maxsize, loff_t eof); +extern loff_t fixed_size_llseek(struct file *file, loff_t offset, + int whence, loff_t size); extern int generic_file_open(struct inode * inode, struct file * filp); extern int nonseekable_open(struct inode * inode, struct file * filp); -- 2.34.1