linux-toradex.git/fs/pipe.c, branch v4.4.8

fs/pipe.c: return error code rather than 0 in pipe_write()

2015-11-11T07:18:26+00:00

pipe_write() would return 0 if it failed to merge the beginning of the
data to write with the last, partially filled pipe buffer.  It should
return an error code instead.  Userspace programs could be confused by
write() returning 0 when called with a nonzero 'count'.

The EFAULT error case was a regression from f0d1bec9d5 ("new helper:
copy_page_from_iter()"), while the ops->confirm() error case was a much
older bug.

Test program:

	#include 
	#include 
	#include 

	int main(void)
	{
		int fd[2];
		char data[1] = {0};

		assert(0 == pipe(fd));
		assert(1 == write(fd[1], data, 1));

		/* prior to this patch, write() returned 0 here  */
		assert(-1 == write(fd[1], NULL, 1));
		assert(errno == EFAULT);
	}

Cc: stable@vger.kernel.org # at least v3.15+
Signed-off-by: Eric Biggers 
Signed-off-by: Al Viro

fs/pipe.c: preserve alloc_file() error code

2015-11-11T07:18:23+00:00

If sys_pipe() was unable to allocate a 'struct file', it always failed
with ENFILE, which means "The number of simultaneously open files in the
system would exceed a system-imposed limit." However, alloc_file()
actually returns an ERR_PTR value and might fail with other error codes.
Currently, in addition to ENFILE, it can fail with ENOMEM, potentially
when there are few open files in the system.  Update sys_pipe() to
preserve this error code.

In a prior submission of a similar patch (1) some concern was raised
about introducing a new error code for sys_pipe().  However, for most
system calls, programs cannot assume that new error codes will never be
introduced.  In addition, ENOMEM was, in fact, already a possible error
code for sys_pipe(), in the case where the file descriptor table could
not be expanded due to insufficient memory.

	(1) http://comments.gmane.org/gmane.linux.kernel/1357942

Signed-off-by: Eric Biggers 
Signed-off-by: Al Viro

VFS: assorted weird filesystems: d_inode() annotations

2015-04-15T19:06:58+00:00

Signed-off-by: David Howells 
Signed-off-by: Al Viro

make new_sync_{read,write}() static

2015-04-12T02:29:40+00:00

All places outside of core VFS that checked ->read and ->write for being NULL or
called the methods directly are gone now, so NULL {read,write} with non-NULL
{read,write}_iter will do the right thing in all cases.

Signed-off-by: Al Viro

fs: move struct kiocb to fs.h

2015-03-26T00:28:11+00:00

struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

new helper: copy_page_from_iter()

2014-05-06T21:39:42+00:00

parallel to copy_page_to_iter().  pipe_write() switched to it (and became
->write_iter()).

Signed-off-by: Al Viro

pipe: switch to ->read_iter()

2014-05-06T21:37:58+00:00

Signed-off-by: Al Viro

start adding the tag to iov_iter

2014-05-06T21:32:49+00:00

For now, just use the same thing we pass to ->direct_IO() - it's all
iovec-based at the moment.  Pass it explicitly to iov_iter_init() and
account for kvec vs. iovec in there, by the same kludge NFS ->direct_IO()
uses.

Signed-off-by: Al Viro

switch pipe_read() to copy_page_to_iter()

2014-04-02T03:19:22+00:00

Signed-off-by: Al Viro

pipe: kill ->map() and ->unmap()

2014-04-02T03:19:19+00:00

all pipe_buffer_operations have the same instances of those...

Signed-off-by: Al Viro