Commit Graph

9 Commits

Author SHA1 Message Date
Eric Dumazet 047fe36052 splice: fix racy pipe->buffers uses
Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered
by splice_shrink_spd() called from vmsplice_to_pipe()

commit 35f3d14dbb (pipe: add support for shrinking and growing pipes)
added capability to adjust pipe->buffers.

Problem is some paths don't hold pipe mutex and assume pipe->buffers
doesn't change for their duration.

Fix this by adding nr_pages_max field in struct splice_pipe_desc, and
use it in place of pipe->buffers where appropriate.

splice_shrink_spd() loses its struct pipe_inode_info argument.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Tom Herbert <therbert@google.com>
Cc: stable <stable@vger.kernel.org> # 2.6.35
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-06-13 21:16:42 +02:00
Hugh Dickins 708e3508c2 tmpfs: clone shmem_file_splice_read()
Copy __generic_file_splice_read() and generic_file_splice_read() from
fs/splice.c to shmem_file_splice_read() in mm/shmem.c.  Make
page_cache_pipe_buf_ops and spd_release_page() accessible to it.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:11 -07:00
Jens Axboe 35f3d14dbb pipe: add support for shrinking and growing pipes
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for
growing and shrinking the size of a pipe and adjusts pipe.c and splice.c
(and relay and network splice) usage to work with these larger (or smaller)
pipes.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:12:40 +02:00
Jens Axboe 2b1ccc0ee9 splice: fix misleading comment
Splice is tied to pipes by design, it'll not change. And now that
the splice stuff is in splice.h (and note pipe.h), the rest of the comment
is out-of-date as well.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-12 11:11:48 +02:00
Miklos Szeredi 328eaaba4e ocfs2: fix i_mutex locking in ocfs2_splice_to_file()
Rearrange locking of i_mutex on destination and call to
ocfs2_rw_lock() so locks are only held while buffers are copied with
the pipe_to_file() actor, and not while waiting for more data on the
pipe.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:12 +02:00
Miklos Szeredi b3c2d2ddd6 splice: split up __splice_from_pipe()
Split up __splice_from_pipe() into four helper functions:

  splice_from_pipe_begin()
  splice_from_pipe_next()
  splice_from_pipe_feed()
  splice_from_pipe_end()

splice_from_pipe_next() will wait (if necessary) for more buffers to
be added to the pipe.  splice_from_pipe_feed() will feed the buffers
to the supplied actor and return when there's no more data available
(or if all of the requested data has been copied).

This is necessary so that implementations can do locking around the
non-waiting splice_from_pipe_feed().

This patch should not cause any change in behavior.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:11 +02:00
Jens Axboe bbdfc2f706 [SPLICE]: Don't assume regular pages in splice_to_pipe()
Allow caller to pass in a release function, there might be
other resources that need releasing as well. Needed for
network receive.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:53:30 -08:00
Jens Axboe 497f9625c2 pipe: allow passing around of ops private pointer
relay needs this for proper consumption handling, and the network
receive support needs it as well to lookup the sk_buff on pipe
release.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-10 08:04:14 +02:00
Jens Axboe d6b29d7cee splice: divorce the splice structure/function definitions from the pipe header
We need to move even more stuff into the header so that folks can use
the splice_to_pipe() implementation instead of open-coding a lot of
pipe knowledge (see relay implementation), so move to our own header
file finally.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-10 08:04:14 +02:00