fs: allocate structure unconditionally in seq_open()
authorYann Droneaud <ydroneaud@opteya.com>
Tue, 30 Jun 2015 21:57:33 +0000 (14:57 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 1 Jul 2015 02:44:57 +0000 (19:44 -0700)
commit189f9841de23a58ecb4b2602db8581512ff08ba4
tree964d5a53219d3a89986518472c408253f4eaa1d4
parentede1bf0dcff2b07001c760992b1ca18fd0f419bc
fs: allocate structure unconditionally in seq_open()

Since patch described below, from v2.6.15-rc1, seq_open() could use a
struct seq_file already allocated by the caller if the pointer to the
structure is stored in file->private_data before calling the function.

    Commit 1abe77b0fc4b485927f1f798ae81a752677e1d05
    Author: Al Viro <viro@zeniv.linux.org.uk>
    Date:   Mon Nov 7 17:15:34 2005 -0500

        [PATCH] allow callers of seq_open do allocation themselves

        Allow caller of seq_open() to kmalloc() seq_file + whatever else they
        want and set ->private_data to it.  seq_open() will then abstain from
        doing allocation itself.

As there's no more use for such feature, as it could be easily replaced by
calls to seq_open_private() (see commit 39699037a5c9 ("[FS] seq_file:
Introduce the seq_open_private()")) and seq_release_private() (see
v2.6.0-test3), support for this uncommon feature can be removed from
seq_open().

Link: http://lkml.kernel.org/r/cover.1433193673.git.ydroneaud@opteya.com
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/seq_file.c