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author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2013-11-14 23:31:56 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-15 01:32:20 +0100 |
commit | 839cc2a94cc3665bafe32203c2f095f4dd470a80 (patch) | |
tree | c48aa0e5bcd3f09ad5b7354396a50928c9211155 | |
parent | lockref: use BLOATED_SPINLOCKS to avoid explicit config dependencies (diff) | |
download | linux-839cc2a94cc3665bafe32203c2f095f4dd470a80.tar.xz linux-839cc2a94cc3665bafe32203c2f095f4dd470a80.zip |
seq_file: introduce seq_setwidth() and seq_pad()
There are several users who want to know bytes written by seq_*() for
alignment purpose. Currently they are using %n format for knowing it
because seq_*() returns 0 on success.
This patch introduces seq_setwidth() and seq_pad() for allowing them to
align without using %n format.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: David Miller <davem@davemloft.net>
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 | 15 | ||||
-rw-r--r-- | include/linux/seq_file.h | 15 |
2 files changed, 30 insertions, 0 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c index a290157265ef..1cd2388ca5bd 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -766,6 +766,21 @@ int seq_write(struct seq_file *seq, const void *data, size_t len) } EXPORT_SYMBOL(seq_write); +/** + * seq_pad - write padding spaces to buffer + * @m: seq_file identifying the buffer to which data should be written + * @c: the byte to append after padding if non-zero + */ +void seq_pad(struct seq_file *m, char c) +{ + int size = m->pad_until - m->count; + if (size > 0) + seq_printf(m, "%*s", size, ""); + if (c) + seq_putc(m, c); +} +EXPORT_SYMBOL(seq_pad); + struct list_head *seq_list_start(struct list_head *head, loff_t pos) { struct list_head *lh; diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index 4e32edc8f506..52e0097f61f0 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -20,6 +20,7 @@ struct seq_file { size_t size; size_t from; size_t count; + size_t pad_until; loff_t index; loff_t read_pos; u64 version; @@ -79,6 +80,20 @@ static inline void seq_commit(struct seq_file *m, int num) } } +/** + * seq_setwidth - set padding width + * @m: the seq_file handle + * @size: the max number of bytes to pad. + * + * Call seq_setwidth() for setting max width, then call seq_printf() etc. and + * finally call seq_pad() to pad the remaining bytes. + */ +static inline void seq_setwidth(struct seq_file *m, size_t size) +{ + m->pad_until = m->count + size; +} +void seq_pad(struct seq_file *m, char c); + char *mangle_path(char *s, const char *p, const char *esc); int seq_open(struct file *, const struct seq_operations *); ssize_t seq_read(struct file *, char __user *, size_t, loff_t *); |