Jason A. Donenfeld f29659bad1 fs: check FMODE_LSEEK to control internal pipe splicing
[ Upstream commit 97ef77c52b789ec1411d360ed99dca1efe4b2c81 ]

The original direct splicing mechanism from Jens required the input to
be a regular file because it was avoiding the special socket case. It
also recognized blkdevs as being close enough to a regular file. But it
forgot about chardevs, which behave the same way and work fine here.

This is an okayish heuristic, but it doesn't totally work. For example,
a few chardevs should be spliceable here. And a few regular files
shouldn't. This patch fixes this by instead checking whether FMODE_LSEEK
is set, which represents decently enough what we need rewinding for when
splicing to internal pipes.

Fixes: b92ce5589374 ("[PATCH] splice: add direct fd <-> fd splicing support")
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:23:31 +02:00
..
2022-06-29 09:03:25 +02:00
2021-08-19 09:02:55 +09:00
2022-07-02 16:41:14 +02:00
2022-06-22 14:22:05 +02:00
2022-08-17 14:22:56 +02:00
2021-08-26 22:28:02 +02:00
2022-06-09 10:22:55 +02:00
2021-12-29 12:28:59 +01:00
2021-09-03 15:33:47 -07:00
2021-08-16 10:50:32 -06:00
2022-05-15 20:18:52 +02:00
2021-08-19 09:02:55 +09:00
2022-06-09 10:23:09 +02:00
2022-07-02 16:41:17 +02:00
2022-07-12 16:35:08 +02:00
2021-12-14 10:57:15 +01:00
2021-08-10 17:57:22 +02:00
2022-07-02 16:41:17 +02:00