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| author | Yann Droneaud <ydroneaud@opteya.com> | 2015-06-30 14:57:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-30 19:44:57 -0700 |
| commit | 189f9841de23a58ecb4b2602db8581512ff08ba4 (patch) | |
| tree | 964d5a53219d3a89986518472c408253f4eaa1d4 | |
| parent | ede1bf0dcff2b07001c760992b1ca18fd0f419bc (diff) | |
| download | lwn-189f9841de23a58ecb4b2602db8581512ff08ba4.tar.gz lwn-189f9841de23a58ecb4b2602db8581512ff08ba4.zip | |
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>
| -rw-r--r-- | fs/seq_file.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c index 555f82155be8..5f163c6c821c 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -51,15 +51,16 @@ static void *seq_buf_alloc(unsigned long size) */ int seq_open(struct file *file, const struct seq_operations *op) { - struct seq_file *p = file->private_data; + struct seq_file *p; + + WARN_ON(file->private_data); + + p = kzalloc(sizeof(*p), GFP_KERNEL); + if (!p) + return -ENOMEM; + + file->private_data = p; - if (!p) { - p = kmalloc(sizeof(*p), GFP_KERNEL); - if (!p) - return -ENOMEM; - file->private_data = p; - } - memset(p, 0, sizeof(*p)); mutex_init(&p->lock); p->op = op; #ifdef CONFIG_USER_NS |