diff options
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index b7f4a1f94d48..9c0485236e68 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -97,6 +97,23 @@ loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) } EXPORT_SYMBOL(generic_file_llseek); +/** + * noop_llseek - No Operation Performed llseek implementation + * @file: file structure to seek on + * @offset: file offset to seek to + * @origin: type of seek + * + * This is an implementation of ->llseek useable for the rare special case when + * userspace expects the seek to succeed but the (device) file is actually not + * able to perform the seek. In this case you use noop_llseek() instead of + * falling back to the default implementation of ->llseek. + */ +loff_t noop_llseek(struct file *file, loff_t offset, int origin) +{ + return file->f_pos; +} +EXPORT_SYMBOL(noop_llseek); + loff_t no_llseek(struct file *file, loff_t offset, int origin) { return -ESPIPE; @@ -258,6 +275,7 @@ ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *pp init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = *ppos; kiocb.ki_left = len; + kiocb.ki_nbytes = len; for (;;) { ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); @@ -313,6 +331,7 @@ ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, lof init_sync_kiocb(&kiocb, filp); kiocb.ki_pos = *ppos; kiocb.ki_left = len; + kiocb.ki_nbytes = len; for (;;) { ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); |