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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2013-11-14 14:31:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-15 09:32:20 +0900
commit839cc2a94cc3665bafe32203c2f095f4dd470a80 (patch)
treec48aa0e5bcd3f09ad5b7354396a50928c9211155
parent57f4257eae33e036125973858934730250d464e3 (diff)
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.c15
-rw-r--r--include/linux/seq_file.h15
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 *);